Patent Publication Number: US-2006005435-A1

Title: Snow plow having reversible wings

Description:
BACKGROUND OF THE INVENTION  
      Field of the Invention  
      The present invention relates generally to snow plows typically used with light and medium duty trucks, and particularly to an improved V-shaped snow plow having reversible wings.  
      Once the exclusive domain of municipality-operated heavy trucks, snow plows have been used with light and medium duty trucks for decades. As would be expected in any area of technology which has been developed for that period of time, snow plows for light and medium duty trucks have undergone tremendous improvement in a wide variety of ways over time, evolving to increase both the usefulness of the snow plows as well as to enhance the ease of using them. The business of manufacturing snow plows for light and medium duty trucks has been highly competitive, with manufacturers of competing snow plows differentiating themselves based on the features and enhanced technology that they design into their products.  
      One of the most important design features of a snow plow is the type of blade or moldboard used to plow the snow. The first type of snow plow design includes a straight, single snow plow blade that is not hinged or V-shaped. These types of blades can be operated in a straight position or can be pivoted left or right about a central axis to push snow to either side of the vehicle. The second type of snow plow design includes a hinged or pivotable snow plow blade. A hinged snow plow blade contains two wings or arms that are hinged about a central axis in order to permit several different blade configurations.  
      A hinged plow blade or moldboard (sometimes referred to as an “apex type” plow blade, “articulated plow blade” or a “V-plow” because the hinge is at the apex of the V formed when the arms or wings of the plow are in a swept back position) allows the operator of the vehicle a greater mechanical advantage since the plow moldboard, with its wings in the swept back V-shaped position, will act like a wedge into the snow. Each wing of the snow plow blade acts like an inclined plane depositing the snow to either side of the vehicle. In addition, the wings of a V-plow can be individually positioned into any configuration—allowing the snow to be pushed to either side of the snow plow.  
      A plow with a straight blade or moldboard also has difficulty in pushing a mound of snow to an out of the way location. For example, with a straight moldboard, snow spills out the sides of the plow while a hinged plow that can be articulated about a central axis can have its wings or arms swept forward to form a V-shaped scoop between the moveable wings/arms of the moldboard. This swept forward position allows for better containment of the snow so that the snow may be moved out of the way without significant spillage.  
      However, there are several disadvantages to conventional hinged snow plow designs. First, hinged snow plow designs include two distinct moldboard wing sections with each section specifically designed to be located on a particular side of the snow plow (i.e. there is a right side wing section and a left side wing section). Thus, each wing section of the snow plow must be separately designed and manufactured, increasing the overall cost of the wing sections and decreasing efficiency of production of the wing sections. Further, wing replacement and on-hand part storage is more difficult with conventional hinge snow plow designs because the plow owner must retain both a right and a left side wing replacement—resulting in increased cost and storage requirements for the plow owner.  
      Further, many hinged snow plow blades contain wings that are hinged together at a single center hinge, causing the plow vehicle and the plow blade to undergo significant stress if the plow blade encounters rocks, manhole covers, curbs or other objects. A single hinge construction can easily damage the snow plow wings/moldboard if the plow hits such objects—rendering replacement of the wings and center section of the plow expensive and time consuming.  
      Even where alternative constructions are utilized, hinged plows are generally not able to trip effectively when a curb or another object is encountered by the plow blade—especially when the plow&#39;s wings are in the V-shaped (swept back) or inverted V-shaped (swept forward) positions. Thus, when objects are hit, the snow plow blade is unable to effectively move, causing damage to the blade as well significant strain on the snow plow vehicle. In conventional constructions, even where the blade is designed to move when an object is encountered, the blade trips with a jerking or forceful effect and returns to plowing position in a similar manner causing significant strain on the snow plow vehicle.  
      In addition, snow plow blade designs typically include hydraulic systems for moving the blade/wings into position. In conventional snow plow designs, these systems are located near the middle or upper portions of the wing section, away from the ground to provide maximum leverage and force for movement and retention of the plow blade into position. However, such a location for the hydraulic system, requires extra force to move the wings, lending to the use of larger and heavier hydraulic cylinders/systems. In addition, this type of configuration requires a heavier snow plow blade in order to keep the blade/scrapers of the snow plow in contact with the road surface in order to effectively remove snow. Clearly, additional weight or mass of the snow plow adversely affects fuel economy, handling of the snow plow and the useful life of the snow plow vehicle.  
      It is accordingly the primary objective of the present invention that it provide a snow plow having reversible wings that are hinged about a center section, wherein the reversible snow plow wing of the present invention may be easily positioned on either side of the snow plow&#39;s center section, eliminating the need for two separately designed and manufactured wing sections. It is a related object of the present invention to provide a reversible snow plow wing that is easily positioned on to and removed from the center section of the snow plow blade, wherein the reversible snow plow wing can be removed from one side and rotated 180 degrees for use on the other side of the snow plow&#39;s center section. It is a further object of the present invention to provide a snow plow having wings positionable in a variety of configurations for the effective removal of snow.  
      It is a further objective to provide a snow plow having reversible wings including a trip spring and dampening cushion design in which the snow plow wings and center section are permitted to tip forward when the plow encounters an object and return back into position in a controlled manner without significant stress on the mechanical structure of the snow plow or the snow plow vehicle.  
      In addition, it can be another objective of the present invention to provide a lighter weight snow plow system in which the hydraulic system utilized in positioning the reversible wings of the present invention is configured in a manner that increases the force and stability of the snow plow blade when in contact with heavy snow, and which requires a lighter hydraulic system. It is a related objective of the present invention to provide snow plow wings, and hence, a lighter snow plow blade that can effectively remove snow and that is less expensive to produce, easier to transport and that causes less mechanical stress on the snow plow vehicle than other conventional snow plow blade configurations.  
      The snow plow of the present invention must also be of construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the snow plow of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the snow plow having reversible wings of the present invention be achieved without incurring any substantial relative disadvantage.  
     SUMMARY OF THE INVENTION  
      The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, a snow plow having reversible wings is presented. It will be at once appreciated by those skilled in the art that the reversible wing design and configuration of the snow plow of the present invention not only provides a lighter, more effective snow plow than conventional hinged snow plow designs, but also provides a snow plow blade having reduced manufacturing costs compared to other, conventional snow plow blade designs.  
      The snow plow of the present invention includes a snow plow blade assembly, an intermediate frame section, a main frame section, and additionally includes hitch pieces for mounting the snow plow onto the snow plow vehicle. The hinged snow plow blade assembly includes two reversible wings or arms and a center section. The reversible wing of the present invention has opposing vertical sides, with one side hinged to the center section and the opposite side extending away from the center section of the snow plow blade. Like typical plow blade constructions, the reversible wing is slightly curved or arcuate-shaped when viewed from either side, similar to that of a snow shovel.  
      The reversible wing of the present invention includes a generally rectangular-shaped frame having a top horizontal member, a bottom horizontal member, a first vertical side portion that is pivotally connected to the center section of the snow plow blade and a second vertical side portion that extends away from the center section of the snow plow blade. The reversible wing is symmetrical about an axis extending from the first vertical side portion to the second vertical side portion, such that top and bottom halves of the reversible wing of the present invention are mirror images of each other.  
      The top horizontal member of the frame of the reversible wing is a three sided U-shaped channel member having a wide channel bottom and side edges/legs of the “U” extending upwardly and outwardly therefrom. When configured as part of the frame, the top horizontal member will be upright i.e., U-shaped with the side edges/legs of the “U” pointing up). The side edge of the U-shaped channel member that will be orientated towards the front of the snow plow when assembled in the wing frame is the front side edge of the channel member, and the side edge of the channel member that will be orientated towards the snow plow vehicle/rear of the snow plow blade when assembled in the wing frame is the rear side edge of the channel member.  
      The top horizontal member contains four sets of apertures for adding additional components to the wing frame. The first and second sets of apertures are located in a spaced-apart fashion along both side edges of the U-shaped channel member. The apertures are located at substantially parallel locations, across from each other, and are spaced-apart along the length of each side edge of the channel member. The first and second sets of apertures can be used to secure the plow blade moldboard, a plow wearstrip, and/or a rear scraper on to the wing frame.  
      The third set of apertures is formed within the channel bottom of the top horizontal member near the middle of the horizontal member. The third set of apertures is used to secure the mounting hardware for a hydraulic, pneumatic or other movement system to the wing frame for moving the wing into different positions. The fourth set of apertures is provided near the outer end of the top horizontal member and can be used to secure mounting hardware for a shoe or support device that will ultimately bear the weight of the snow plow blade during use of the snow plow.  
      The bottom horizontal member of the wing frame of the present invention is also a U-shaped channel member and is the mirror image of the top horizontal member. Accordingly, when configured as part of the frame, the bottom horizontal member will be inverted “U” i.e., with the side edges/legs of the “U” extending downwardly. In addition, the bottom horizontal member contains four set of apertures having substantially symmetrical or mirror image placement on the U-shaped channel member as the top horizontal member. It will be readily apparent to those skilled in the art that the symmetry of the apertures on the top and bottom horizontal members permit the wing of the present invention to be reversible, i.e. to be rotated 180 degrees, with the top horizontal member being located in the position of the bottom horizontal member and vice versa, while permitting the wing components (such as the moldboard, wearstrip, support shoe, and cylinder hardware) to be mounted in the proper location on the wing frame.  
      The top horizontal member and the bottom horizontal member are joined at their respective outer ends by a vertical end rib, located at the second vertical side portion of the frame. The end rib is mounted to and overlies each of the ends of top horizontal member and the bottom horizontal member and has an arcuate shape when viewed from the side, providing the reversible wing with its overall shape. A curved face plate is located adjacent to the end rib and is mounted to the top and bottom horizontal members near the front side edges, respectively, to add additional support to the wing frame.  
      The top horizontal member and the bottom horizontal member are joined at their respective inner ends by a rectangular-shaped wing support member that extends from the front side edges of the top to the bottom horizontal members, respectively, to the rear side edges of the top to the bottom horizontal members—adding substantial strength to the wing frame. A vertical rib is mounted adjacent to the wing support member and extends from the top to the bottom horizontal member. A curved face plate is located adjacent to the vertical rib and is mounted to the top and bottom horizontal members near the front side edges, respectively, to add additional support to the inner vertical side of the wing frame.  
      A plurality of hollow tubular hinge pieces are welded to the wing support member along a side thereof to permit the first vertical portion of the reversible wing to be hinged to the center section of the snow plow blade. An L-shaped blade stop that extends from the top horizontal member to the bottom horizontal member is also joined to the wing support member along the side thereof, to provide a limit to the pivot movement of the wing.  
      Completing the wing frame is an additional vertical rib that is positioned between the outer and inner vertical ends of the wing frame. The vertical rib is joined at its top and bottom to the top and bottom horizontal members, respectively, to add support to the mid-section of the wing frame.  
      As previously described, complete assembly of the reversible wing of the present invention includes securing several additional components to the wing frame. For example, a skin or moldboard is mounted to the wing frame using retainer members and the apertures formed on the front side of the top and bottom horizontal members. In addition, the snow plow wearstrip, having approximately the same length as the top and bottom horizontal members, is removably bolted on to the bottom horizontal member at the front side edge thereof using the apertures provided therein. Optionally, a rear scraper blade having approximately the same length as the top and bottom horizontal members can be removably bolted on to the bottom horizontal member at the rear side edge thereof using the apertures provided therein.  
      The assembled wing also includes mounting hardware for retaining a hydraulic cylinder or other mechanism used for moving the snow plow wing into the desired position. The mounting hardware is removably attached to the bottom horizontal member of the wing frame using the third set of apertures formed therein.  
      Finally, the assembled reversible wing of the present invention also includes a support shoe for supporting the weight of the wing during use of the snow plow. The support shoe is removably mounted to the bottom horizontal member of the wing frame using the fourth set of apertures formed therein.  
      As described above, the frame of the reversible wing of the present invention is symmetrical about a horizontal axis at approximately the midpoint of the first vertical side portion and the second vertical side portion of the assembled wing frame. In this way, regardless of the components or accessories removably mounted to the wing frame, the wing may be removed from one side of the center section, rotated 180 degrees and remounted to the opposite side of the center section.  
      Likewise, the symmetry of the wing frame permits production of a single wing frame for use in the hinged snow plow of the present invention, rather than requiring two distinct wings to be manufactured—thus, reducing the manufacturing time and cost associated with production of a snow plow and reducing the maintenance time and cost in operating the snow plow.  
      The center section of the snow plow blade of the present invention is a substantially triangular-shaped tower and is oriented within the snow plow blade such that two slanted sides and one edge of the triangle tower formed at the intersection thereof project towards the rear of the snow plow blade and the snow plow vehicle, and with the flat side of the triangle and the other two edges of the triangle tower facing the front of the snow plow blade.  
      The top rear portion of the center section includes a flat plate that extends outwardly from the rear edge and sides of the triangle tower. The flat plate includes two spring retainer bolts for mounting a trip spring thereto—permitting the center section and wings to tip forward if the snow plow blade encounters an object.  
      The bottom portion of the front side of the center section includes apertures formed therein for mounting a center blade onto the center section. The two forward edges of the front side of the center section contain a plurality of hollow tubular hinge pieces for pivotally attaching two snow plow wings to the center section of the snow plow. The tubular hinge pieces are arranged along each of the forward edges of the center section in a manner that permits the tubular hinge pieces to coaxially interfit with the tubular hinge pieces located on each snow plow wing.  
      The hinged snow plow blade assembly of the present invention is assembled by removably attaching each reversible wing to the center. A first wing is pivotally attached at its first vertical side portion to the center section by interfitting the hollow tubular hinge pieces of the wing with the hollow tubular hinge pieces located on one side of the center section. The tubular hinge pieces form one elongated tube in which a pin may be fit, joining the wing to the center section. Likewise, a second wing is pivotally attached at its first vertical side portion to the center section by interfitting the hollow tubular hinge pieces of the wing with the hollow tubular hinge pieces located on the opposite side of the center section. The tubular hinge pieces form one elongated tube in which a pin may be fit, joining the wing to the center section.  
      The bottom rear portion of the center section includes two mounting brackets for retaining the end of the hydraulic cylinders which will be secured at the other end to each bottom horizontal member of the wings of the snow plow. It will be readily apparent to those skilled in the art that because the location of the cylinder is located at the bottom of the center section and each of the snow plow wings and substantially parallel to each of the snow plow wings, the cylinders will be able to deliver a larger, more effective amount of force to the wings provide the wings with greater stability and resistance to heavy load conditions over other more traditional cylinder positions.  
      The bottom rear portion of the center section also includes two apertures that will receive the intermediate frame section of the snow plow. Importantly, the bottom rear portion of the center section further includes a stop plate which will act as a limit to prevent the snow plow blade from tipping beyond a certain point when the snow plow blade encounters an object.  
      The intermediate frame section of the present invention is provided with apertures that will receive the opposite ends of the trip springs and a cushion which will engage the stop plate of the center section. When the snow plow blade hits an object, the trip springs permit the top blade to tip forward, preventing potential damage to the snow plow. When the object is no longer an impediment or when the snow plow vehicle backs away, the cushion and the stop plate prevent the snow plow blade from forcefully snapping back into position—elevating stress on both the snow plow blade and the snow plow vehicle.  
      Finally, assembly of the snow plow is completed by mounting the main frame section onto the intermediate frame section, and using hitch pieces to mount the snow plow onto a snow plow vehicle.  
      It may therefore be seen that the present invention teaches a snow plow having reversible wings wherein the snow plow blade may be more efficiently and more economically manufactured than other snow plow blade designs. The hinged snow plow blade of the present invention eliminates the need for wing designs that are specifically intended for the “right” side or the “left” side of the snow plow.  
      It may also be seen that the hinged snow plow blade of the present invention is provided with a hydraulic system that is located at the very bottom of each wing of the present invention, in order to more effectively transfer force to the snow plow blade, utilizing minimal hydraulic power. It will be appreciated by those skilled in the art that this configuration provides the hinged snow plow of the present invention a mechanical advantage over hydraulic mechanisms located further up on the snow plow blade, such that the reversible wing of the present invention may be lighter in weight while still retaining the structural strength and effectiveness of heavier snow plow wings.  
      The snow plow having reversible wings of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow having reversible wings of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved without incurring any substantial relative disadvantage.  
    
    
     DESCRIPTION OF THE DRAWINGS  
      These and other advantages of the present invention are best understood with reference to the drawings, in which:  
       FIG. 1  is a perspective view of a wing frame for use in a reversible wing of a snow plow blade assembly present invention;  
       FIG. 2  is a front view of the wing frame of the reversible wing illustrated in  FIG. 1 ;  
       FIG. 3  is a top plan view of the wing frame of the reversible wing illustrated in  FIGS. 1 and 2 ;  
       FIG. 4   a  is an exploded view of the wing frame of the reversible wing illustrated in  FIGS. 1 through 3 , showing the assembly of a moldboard and a wearstrip onto the wing frame as well as various other snow plow blade components;  
       FIG. 4   b  is a partial cross-sectional view of the top of the reversible wing illustrated in  FIG. 4   a , showing how the top of the moldboard is retained by the plow frame;  
       FIG. 4   c  is a partial cross-sectional view of the bottom of the reversible wing illustrated in  FIG. 4   a , showing how the bottom of the moldboard is retained by the plow frame;  
       FIG. 5  is perspective view of the rear side of the reversible wing illustrated in  FIGS. 4   a  through  4   c;    
       FIG. 6  is a perspective view of a center section for use in the snow plow blade assembly of the present invention;  
       FIG. 7  is a top plan view of the center section illustrated in  FIG. 6 ;  
       FIG. 8  is a side view of the center section illustrated in  FIGS. 6 and 7 ;  
       FIG. 9  is a front view of the center section illustrated in  FIGS. 6 through 8 ;  
       FIG. 10  is a rear view of the center section illustrated in  FIGS. 6 through 9 ;  
       FIG. 11  is a bottom plan view of the center section illustrated in  FIGS. 6 through 11 ;  
       FIG. 12  is a perspective view of an intermediate section for use in a snow plow frame assembly of the present invention;  
       FIG. 13  is a top plan view of the intermediate section illustrated in  FIG. 12 ;  
       FIG. 14  is a cross-section view of the intermediate section illustrated in  FIGS. 12 and 13  taken along the line  14 - 14 ;  
       FIG. 15  is a perspective view of a front portion of the intermediate section illustrated in  FIGS. 12 through 14 ;  
       FIG. 16  is a perspective view of a main frame for use in the snow plow frame assembly of the present invention;  
       FIG. 17  is a top plan view of the main frame illustrated in  FIG. 16 ;  
       FIG. 18  is a right side view of the main frame illustrated in  FIGS. 16 and 17 ;  
       FIG. 19  is a front view of the main frame illustrated in  FIGS. 16 and 17 ;  
       FIG. 20  is a rear view of the main frame illustrated in  FIGS. 16 through 19 ;  
       FIG. 21  is a cross-section view of the main frame illustrated in  FIG. 16 , taken along the line  21 - 21  of  FIG. 17 , with the intermediate section shown in shadow;  
       FIG. 22  is a perspective view of a pivoting lift bar which will be pivotally mounted at the rear end of the main frame illustrated in  FIGS. 16 through 21 ;  
       FIG. 23  is a perspective view of a hitch frame nose piece which will be mounted on a truck under the front bumper thereof;  
       FIG. 24  is a perspective view of a bellcrank which is used to operate the pivoting lift bar illustrated in  FIG. 22 ;  
       FIG. 25  is a perspective view of a lift link which connects the bellcrank illustrated in  FIG. 24  to the pivoting lift bar illustrated in  FIG. 22 ;  
       FIG. 26  is a cutaway view of the various components of the snow plow frame assembled together, showing the hydraulic cylinder used to pivot the lift bar;  
       FIG. 27  is a partial view from the top showing the hitch mounting mechanism on one side of the snow plow illustrated in  FIG. 26  prior to installation;  
       FIG. 28  is a partial view from the top showing the components illustrated in  FIG. 27  in a mounted position;  
       FIG. 29  is a front perspective view of the snow plow of the present invention, showing the snow plow blade assembly exploded;  
       FIG. 30  is a rear perspective view of the snow plow of the present invention, showing the snow plow blade assembly exploded;  
       FIG. 31  is a rear perspective view of the assembled snow plow of the present invention;  
       FIG. 32  is a side view of the center section illustrated in  FIGS. 6 through 11  and the intermediate section illustrated in  FIGS. 12 through 15 , showing the connection thereof;  
       FIG. 33  is a partial rear view of the assembled center section and the intermediate section illustrated in  FIG. 32 ;  
       FIG. 34  is a cross-sectional partial side view of the assembled center section and the intermediate section illustrated in  FIGS. 32 and 33 , taken along the line  34 - 34  of  FIG. 33 , showing the center section in its normal position;  
       FIG. 35  is a cross-sectional partial side view of the assembled center section and the intermediate section illustrated in  FIGS. 32 through 34 , taken along the line  34 - 34 , showing the center section in its tripped position;  
       FIG. 36  is a top plan view of the intermediate section illustrated in  FIGS. 12 through 15  and the main frame illustrated in  FIGS. 16 through 21 , showing the connection thereof;  
       FIG. 37  is a side view of the assembled intermediate section and the main frame illustrated in  FIG. 35 ;  
       FIG. 38  is a partial cross-sectional view from the front showing the components illustrated in  FIGS. 29 through 31  in a mounted position with the retaining pin inserted;  
       FIG. 39  is a side view of the snow plow illustrated in  FIGS. 29 through 31  as the hitch frame nose piece is brought into engagement with a mounting pin on the pivoting lift bar;  
       FIG. 40  is a schematic depiction of the engagement of the mounting pin with a slot in the hitch frame nose piece;  
       FIG. 41  is a side view similar to that of  FIG. 39 , with the pivoting lift bar beginning to pivot to bring the mounting pin into engagement with the slot in the hitch frame nose piece;  
       FIG. 42  is a side view similar to that of  FIGS. 39 and 41 , with the pivoting lift bar pivoted to bring the mounting holes in the pivoting lift bar into alignment with the mounting holes in the hitch frame nose piece;  
       FIG. 43   a  is a top plan view of the snow plow of the present invention illustrated with each of the reversible wings in a swept back position; and  
       FIG. 43   b  is a top plan view of the snow plow of the present invention illustrated with each of the reversible wings in a swept forward position.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      The snow plow having reversible wings of the present invention comprises, in its simplest form, a snow plow blade assembly  46  including a center section  48  and reversible wings  50  and  51  removably attached at opposite sides thereto, as best shown in  FIG. 29 . Accordingly, the preferred embodiment of the present invention is illustrated in a series of figures, of which  FIGS. 1 through 5  are components of the reversible wing  50 .  FIGS. 6 through 25  include components of the snow plow of the present invention and  FIGS. 26 through 43  illustrate the manner in which the snow plow having reversible wings is assembled and attached to a snow plow vehicle.  
      Referring first to  FIGS. 1 and 2 , a frame  52  for the reversible wing  50  of the present invention is illustrated. The frame  52  has a top portion indicated generally at  54 , a bottom portion indicated generally at  56 , and substantially parallel vertical side portions indicated generally at  58  and  60 . The frame  52  also has a front side indicated generally at  62  that will face away from the snow plow vehicle when the reversible wing  50  is positioned on to a snow plow blade, and a rear side indicated generally at  64  that will face towards the snow plow vehicle when the reversible wing  50  is positioned on to a snow plow blade.  
      The top portion  54  of the frame  52  includes a top horizontal member  66  that is constructed of a three sided channel member resembling a wide “U”, having a channel bottom  68 , front and rear legs  70  and  72  which angle upward and outward from the channel bottom  68  and having first and second ends  74  and  76 . A notch  78  is cut out of the front leg  70  on the second end  76  of the top horizontal member  66  for accommodating a hinge mechanism, as will be described below. The top horizontal member  66  is preferably constructed of steel.  
      Referring to  FIG. 3  in addition to  FIGS. 1 and 2 , the top horizontal member  66  of the frame includes several sets of apertures for securing several snow plow components to the frame  52  of the reversible wing  50 . A first set of apertures  80  is located on the front leg  70  of the top horizontal member  66 . The apertures  80  are substantially equally spaced in the longitudinal direction along the front leg  70  of the top horizontal member  66  and are linearly arranged with respect to each other. Preferably the first set of apertures  80  includes five equally spaced apertures. Apertures  80  are provided for securing a moldboard (or skin) to the frame  52  of the reversible wing  50 , as will be described in more detail with respect to  FIGS. 4   a - 4   c  and  5 .  
      A second set of apertures  82  is located on the rear leg  72  of the top horizontal member  66 . The apertures  82  are substantially equally spaced in the longitudinal direction along the rear leg  72  of the top horizontal member  66  are linearly arranged with respect to each other. Preferably the second set of apertures  82  includes five equally spaced apertures. Apertures  82  are provided for securing a rear scraper to the frame  52  of the reversible wing  50  when the is in an inverted position, as will be described in more detail herein.  
      A third set of apertures  84  is located within the channel bottom  68  of the top horizontal member  66 . The apertures  84  are located along the channel bottom  68  at approximately the midpoint of the top horizontal member  66 , slight towards the second end  76  of the top horizontal member  66 . Preferably, the third set of apertures  84  includes four apertures arranges substantially in a rectangular arrangement, as illustrated in  FIG. 3 . Apertures  84  are provided for securing the hardware and/or support mechanism for a hydraulic system to the frame  52  of the reversible wing  50  when the snow plow blade is completely assembled, as will be described in more detail with respect to  FIG. 5 .  
      A fourth set of apertures  86  is provided for securing additional components, such as a shoe support to the frame  52  of the reversible wing  50 , as will be described in more detail with regard to  FIG. 5 . The fourth set of apertures is located both within the channel bottom  68  and on the rear leg  72  of the top horizontal member  66 .  
      It will be appreciated by those skilled in the art that first, second, third and fourth sets of apertures  80 - 86  may contain any number and any size of apertures required to secure the required snow plow components to the frame  52  of the reversible wing  50 .  
      The bottom portion  56  of the frame  52  includes a bottom horizontal member  88  that is substantially the mirror image of the top horizontal member  66 . Accordingly, the bottom horizontal member  88  is constructed of a three sided channel member resembling a wide inverted “U”, having a channel bottom  90 , front and rear legs  92  and  94  which angle upward and outward from the channel bottom  90  and first and second ends  96  and  98 . A notch  100  is cut out of the front leg  92  on the second end  98  of the bottom horizontal member  88  for accommodating a hinge mechanism, as will be described more fully herein. The bottom horizontal member  88  is preferably constructed of steel.  
      The bottom horizontal member  88  of the frame  52  includes several sets of apertures for securing snow plow components to the frame  52  of the reversible wing  50 . A first set of apertures  102  is located on the front leg  92  of the bottom horizontal member  88 . The apertures  102  are substantially equally spaced in the longitudinal direction along the front leg  92  of the bottom horizontal member  88  and are linearly arranged with respect to each other. Preferably the first set of apertures  102  includes five equally spaced apertures. Apertures  102  are provided for securing a wearstrip and/or the moldboard to the frame  52  of the reversible wing  50 , as will be described in more detail with respect to  FIG. 5 .  
      A second set of apertures  104  is located on the rear leg  94  of the bottom horizontal member  88 . The apertures  104  are substantially equally spaced in the longitudinal direction along the rear leg  94  of the bottom horizontal member  88  are linearly arranged with respect to each other. Preferably the second set of apertures  104  includes five equally spaced apertures. Apertures  104  are provided for securing a rear scraper to the frame  52  of the reversible wing  50 , as will be described in more detail with respect to  FIG. 5 .  
      A third set of apertures  106  is located within the channel bottom  90  of the bottom horizontal member  88 . The apertures  106  are located along the channel bottom  90  at approximately the midpoint of the bottom horizontal member  88 , slightly towards the second end  98  of the bottom horizontal member  88 . Preferably, the third set of apertures  106  includes four apertures arranges substantially in a rectangular arrangement (not all apertures  106  are visible in  FIG. 1 ). Apertures  106  are provided for securing the hardware and/or support mechanism for a hydraulic system to the frame  52  of the reversible wing  50 , as will be described elsewhere herein.  
      A fourth set of apertures  108  is provided for securing additional components, such as a shoe support to the frame  52  of the reversible wing  50 , as will be described in more detail with regard to  FIG. 5 . The fourth set of apertures  108  is located both within the channel bottom  90  and on the rear leg  94  of the bottom horizontal member  88 . The first, second, third and fourth sets of apertures  102 - 108  may contain any number and any size of apertures required to secure the required snow plow components to the frame  52  of the reversible wing  50 .  
      It will be readily apparent to those skilled in the art that the top horizontal member  66  and the bottom horizontal member  88  may be provided pre-drilled with each of the sets of apertures  80 - 86  and  102 - 108 , respectively, before complete assembly of the frame  50 , or that the top horizontal member  66  and the bottom horizontal member  88  may be provided without such sets of apertures and drilled after assembly of the frame  52 . Consistent with the broader aspects of the present invention, however, the top horizontal member  66  and the bottom horizontal member  88  may be completely absent the sets of apertures  80 - 86  and  102 - 108 , respectively, with additional snow plow components of the reversible wing  50  being mounted to the frame  52  by welding or securing such components by other methods known to those skilled in the art.  
      Importantly, however, when arranged within the frame  52 , the top horizontal member  66  and the bottom horizontal member  88  are substantially the mirror image of each other. In particular, in highly preferred embodiments of the present invention, the configuration and placement of the first through fourth sets of apertures  102 - 104  in the bottom horizontal member  88  will be the mirror image of the first through fourth sets of apertures  80 - 86  in the top horizontal member  66  in order to permit the frame  52  of the reversible wing  50  to be utilized on either side of the center section  48  of the hinged snow plow blade assembly  46 .  
      The vertical side portion  58  of the frame  52  of the reversible wing  50  of the present invention includes an end rib  110 . The end rib  110  is mounted to the first end  74  of the top horizontal member  66  and the first end  96  of the bottom horizontal member  88 , thereby overlying them as best shown in  FIG. 1 . The end rib  110  is preferably made of steel and preferably welded to each of the top horizontal member  66  and the bottom horizontal member  88 , although any other method of attachment known to those skilled in the art is contemplated by the present invention. As illustrated in  FIG. 1 , the end rib  110  has an arcuate shape when viewed from the side.  
      A middle rib  112  is located between each of the vertical side portions  58  and  60  of the frame  52  of the reversible wing  50 . The middle rib  112  extends between the top horizontal member  66  and the bottom horizontal member  88  and is mounted at each end thereto. To mount the middle rib  112  in place on the frame  52 , the middle rib  112  may be provided with a length that permits each end of the middle rib  112  to extend through apertures in the channel bottom  68  and  90  of the top horizontal member  66  and the bottom horizontal member  88 , respectively. The middle rib  112  is preferably made of steel and preferably welded to each of the top horizontal member  66  and the bottom horizontal member  88 , although any other method of attachment known to those skilled in the art is contemplated by the present invention. As illustrated in  FIG. 1 , the middle rib  112  has an arcuate shape when viewed from the side.  
      The vertical side portion  60  of the frame  52  of the reversible wing  50  of the present invention is the side of the frame  52  that will be hinged in place to the center section  48  of the snow plow blade assembly  46 . Accordingly, the vertical side portion  60  includes a generally rectangular wing support member  114 . As best viewed from  FIG. 3 , the wing support member  114  has a front face  116 , a rear face  118  and sides  120  and  122 . The wing support member  114  is mounted at its top end to the channel bottom  68  of the top horizontal member  66  whereby the front face  116  of the wing support member  114  is mounted in substantial alignment with the channel bottom  68  near the front leg  70  thereof and the rear face  118  of the wing support member  114  is mounted in substantial alignment with the channel bottom  68  near the rear leg  72  thereof. Likewise, the wing support member  114  is mounted at its bottom end to the channel bottom  90  of the bottom horizontal member  98  whereby the front face  116  of the wing support member  114  is mounted in substantial alignment with the channel bottom  90  near the front leg  92  thereof and the rear face  118  of the wing support member  114  is mounted in substantial alignment with the channel bottom  90  near the rear leg  94  thereof. Preferably, the wing support member  114  is constructed of steel and welded to the top horizontal member  66  and the bottom horizontal member  88 .  
      A support rib  124  is located adjacent to the wing support member  114  near the side  122  thereof. The support rib  124  extends between the top horizontal member  66  and the bottom horizontal member  88 , is mounted at each end thereto and is mounted at one side to the side  122  of the wing support member  114 . Like the middle rib  112 , the support rib  124  may be provided with a length that permits each end of the support rib  124  to extend through apertures in the channel bottom  68  and  90  of the top horizontal member  66  and the bottom horizontal member  88 , respectively. The support rib  124  is preferably made of steel and preferably welded to each of the top horizontal member  66  and the bottom horizontal member  88 , although any other method of attachment known to those skilled in the art is contemplated by the present invention. The support rib  124  has an arcuate shape when viewed from the side.  
      As best shown in  FIGS. 2, 4   b  and  4   c , the frame  52  includes two retainer plates  126  and  128  for supporting the skin/moldboard on the reversible wing  50 . The retainer plate  126  extends from the vertical side portion  58  to the vertical side portion  60  of the frame  52  and is mounted to the top horizontal member  66  on the channel bottom  68  near the front leg  70  thereof. The retainer plate  126  is preferably constructed of steel and welded to the top horizontal member  66 , the end rib  110 , the middle rib, the support rib  124  and any other portion of the frame  52  required to secure the retainer plate  126  in place.  
      Likewise, the retainer plate  128  extends from the vertical side portion  58  to the vertical side portion  60  of the frame  52  and is mounted to the bottom horizontal member  88  on the channel bottom  90  near the front leg  92  thereof. The retainer plate  126  is preferably constructed of steel and welded to the bottom horizontal member  88 , the end rib  110 , the middle rib, the support rib  124  and any other portion of the frame  52  required to secure the retainer plate  126  in place.  
      A curved support plate  130  is located adjacent to the end rib  110  and is mounted at one side thereto. The curved support plate  130  extends from the retainer plate  126  on the top horizontal member  66  to the retainer plate  128  on the bottom horizontal member  88  and is mounted at one end to the retainer plate  126  and is mounted at the other end the retainer plate  128 . The curved support plate  130  is preferably constructed of steel and preferably mounted in place on to the frame  52  by welding.  
      A curved support plate  132  is located adjacent to the support rib  124  and is mounted at one side thereto. The curved support plate  132  extends from the retainer plate  126  on the top horizontal member  66  to the retainer plate  128  on the bottom horizontal member  88  and is mounted at one end to the retainer plate  126  and is mounted at the other end the retainer plate  128 . The curved support plate  132  is preferably constructed of steel and preferably mounted in place on to the frame  52  by welding.  
      A plurality of hollow, tubular hinge pieces  134  are mounted onto the vertical side portion  60  of the frame  52  in order to permit the reversible wing  50  to hingedly attach to the center section  48  of the snow plow blade assembly  46 . Preferably, four tubular hinge pieces  134  are used in the present invention. However, any number of tubular hinge pieces  134  may be used to secure the reversible wing  50  to the center section  48 . Further, any other pivotable connection mechanism know to those skilled in the art may also be used to attach the reversible wing  50  to the center section  48 .  
      As best illustrated in  FIG. 3 , the tubular hinge pieces  134  are mounted to the wing support member  114  along a corner  136  thereof at substantially the intersection of the front face  116  and the side  120  of the wing support member  114 . The tubular hinge pieces  134  are mounted spaced-apart in axial alignment on the corner  136  of the wing support member  112  from a position on the wing support member  114  just below the notch  78  on the second end  76  of the top horizontal member  66  to a position on the wing support member  114  just above the notch  100  on the second end  98  of the bottom horizontal member  88 . The tubular hinge pieces  134  are preferably constructed of steel and are mounted to the wing support member  114  by welding.  
      A blade stop  138  is mounted to the side  120  of the wing support member  114  to provide a limit to the hinged movement of the reversible wing  50 . The blade stop  138  is substantially L-shaped and is mounted to the wing support member  114  extending from the top to the bottom of the wing support member  114  at a position just adjacent to the tubular hinge pieces  134 . The blade stop  138  is preferably constructed of steel and is mounted to the wing support member  114  by welding.  
      Before additional snow plow components are attached to the frame  52  of the present invention, it will be readily apparent to those skilled in the art that the frame  52  is substantially symmetrical about a horizontal axis extending from approximately the midpoint of the vertical side portion  58  to approximately the midpoint of the vertical side portion  60 . Accordingly, the frame  52  may be hingedly attached to either side of the center section of the snow plow of the present invention by simply inverting the frame  52  (i.e. rotating the frame 180 degrees about that horizontal axis). Thus, the frame  52  can be used to construct the reversible wing  50  of the present invention, as described below, for use on one side, i.e. the left side, of the center section  48  of the snow plow blade assembly  46 , as shown in  FIG. 29 . It will also be apparent to those skilled in the art that the frame  52  may be used to construct the reversible wing  51  to be pivotally attached to the opposite side, i.e. the right side, of the center section  46 , depending on the position of the additional components mounted to the frame  52 , as shown in  FIG. 29 .  
      Referring to  FIGS. 4   a  through  4   c  and  5 , in addition to  FIGS. 1 through 3 , the frontmost portions of the top horizontal member  66 , the retainer plate  126 , the curved support plate  130 , the end rib  110 , the bottom horizontal member  88 , the retainer plate  128 , the curved support plate  132  and the support rib  124  together define a curved support surface which will support a moldboard  140  thereupon. The moldboard  140  may be made of steel, or alternatively may be constructed of a man-made material such as polycarbonate, which may be clear, or other man-made materials such as ultra-high molecular weight (UHMW) polyethylene.  
      Extending across the front side  62  of the frame  52  is a moldboard retainer strip  142  into which the top edge of the moldboard  140  fits and is retained. The moldboard retainer strip  142  contains a plurality of apertures  144  formed therein matching the pattern of the first set of apertures  80  formed in the top horizontal member  66 . (It will be appreciated by those skilled in the art that the apertures  144  formed in the moldboard retainer strip  142  also substantially match the pattern of the first set of apertures  102  formed in the front leg  92  of the bottom horizontal member  88  as the bottom horizontal member  88  is the mirror image of the top horizontal member  66 ). The moldboard retainer strip  142  is removably attached to the top horizontal member  66  using bolts  146  that secure the moldboard retainer strip  142  to the top horizontal member  66 . The moldboard retainer strip  142  is preferably constructed of steel, however, any rigid material known to those skilled in the art may be used.  
      Alternately, if the apertures  144  and  80  are not tapped, bolts and nuts could be used to mount the moldboard retainer strip  142  onto the top horizontal member  66 . Optionally, the apertures  144  in the moldboard retainer strip  142  may be countersunk to recess the heads of the bolts  146  to the level of the surface of the wearstrip moldboard retainer strip  142 .  
      The bottom edge of the moldboard  140  comes just to the top of the bottom horizontal member  88 , as shown in  FIG. 4   c . A wearstrip  148  which is approximately the same width as the bottom horizontal member  88  has a plurality of apertures  150  formed therein that substantially match the pattern of the first set of apertures  102  formed in the front leg  92  of the bottom horizontal member  88 . (It will be appreciated by those skilled in the art that the apertures  150  formed in the wearstrip  148  also substantially match the pattern of the first set of apertures  80  formed in the front leg  70  of the top horizontal member  66 , as the top horizontal member  66  is the mirror image of the bottom horizontal member  88 ).  
      The wearstrip  148  is bolted on to the bottom horizontal member  88  with a plurality of bolts  152 . Alternately, if the apertures  150  and  102  are not tapped, bolts and nuts could be used to mount the wearstrip  148  onto the bottom horizontal member  88 . Optionally, the apertures  150  in the wearstrip  148  may be countersunk to recess the heads of the bolts  152  to the level of the surface of the wearstrip  148 . The front leg  92  of the bottom horizontal member  88  is arranged and configured such that the wearstrip  148  will be mounted with its bottom edge angled forwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred.  
      When the wearstrip  148  is bolted to the bottom horizontal member  88 , it will be appreciated by those skilled in the art that it extends well below the bottom horizontal member  88 , so that as it is worn down, the bottom horizontal member  88  will not be damaged by contact with the ground. The wearstrip  148  is preferably constructed of a high carbon steel such as AISI 1080 high carbon steel. However, the wearstrip may be constructed of any strong, rigid material known to those skilled in the art able to withstand the force necessary for moving a substantial amount of snow.  
      The wearstrip  148  retains the bottom of the moldboard  140  in place, and it will at once be appreciated that the moldboard  140  may be replaced by merely removing the wearstrip  148 , making the replacement substantially easier than in earlier snow plow blade designs.  
      As best illustrated in  FIG. 5 , mounting hardware  154  for mounting a hydraulic system or other system for moving the reversible wing  50  is removably attached to the frame  52  on the bottom horizontal member  88 . The mounting hardware  154  has a plurality of apertures  156  formed therein that substantially match the pattern of the third set of apertures  106  formed in the channel bottom  90  of the bottom horizontal member  88 . (It will be appreciated by those skilled in the art that the apertures  156  formed in the mounting hardware  154  also substantially match the pattern of the third set of apertures  84  formed in the channel bottom  68  of the top horizontal member  66 , as the top horizontal member  66  is the mirror image of the bottom horizontal member  88 ).  
      The mounting hardware  154  is removably bolted on to the bottom horizontal member  88  with a plurality of bolts (not shown in  FIG. 5 ). Alternately, if the apertures  156  and  106  are not tapped, bolts and nuts could be used to secure the mounting hardware  154  onto the bottom horizontal member  88 .  
      Support shoe mounting hardware  160  for mounting a support shoe assembly  162  onto the frame  52  is secured to the bottom horizontal member  88 . The support shoe mounting hardware  160  has a plurality of apertures  164  formed therein that substantially match the pattern of the fourth set of apertures  108  formed in the bottom horizontal member  88 . (It will be appreciated by those skilled in the art that the apertures  164  formed in the support shoe mounting hardware  160  also substantially match the pattern of the fourth set of apertures  86  formed in the top horizontal member  66 , as the top horizontal member  66  is the mirror image of the bottom horizontal member  88 ).  
      The support shoe mounting hardware  160  is removably bolted on to the bottom horizontal member  88  with a plurality of bolts (not shown in  FIG. 5 ). Alternately, if the apertures  164  and  108  are not tapped, bolts and nuts could be used to mount the support shoe mounting hardware  160  on to the bottom horizontal member  88 .  
      Optionally, the reversible wing  50  of the present invention includes a rear scraper blade  168 , which is approximately the same length as the bottom horizontal member  88 . The rear scraper blade  168  has a plurality of apertures  170  formed therein that substantially match the pattern of the second set of apertures  104  formed in the rear leg  94  of the bottom horizontal member  88 . (It will be appreciated by those skilled in the art that the apertures  170  formed in the rear scraper blade  168  also substantially match the pattern of the second set of apertures  82  formed in the rear leg  74  of the top horizontal member  66 , as the top horizontal member  66  is the mirror image of the bottom horizontal member  88 ).  
      The rear scraper blade  168  is removably bolted on to the bottom horizontal member  88  with a plurality of bolts  172 . Alternately, if the apertures  170  and  104  are not tapped, bolts and nuts could be used to mount the rear scraper blade  168  onto the bottom horizontal member  88 . Optionally, the apertures  170  in the rear scraper blade  168  may be countersunk to recess the heads of the bolts  172  to the level of the surface of the rear scraper blade  168 . The rear leg  94  of the bottom horizontal member  88  is arranged and configured such that the rear scraper blade  168  will be mounted with its bottom edge angled forwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred.  
      Consistent with the broader aspects of the present invention, the reversible wing  51  of the present invention, which is hingedly attached to the center section  48  of the snow plow blade assembly  46  opposite of the reversible wing  50 , is easily constructed using the frame  52  and removable snow plow components as described above. It will be appreciated by those skilled in the art that in order to provide the reversible wing  51 , the frame  52  is provided and is rotated 180 degrees so that the bottom horizontal member  88  and the top horizontal member  66  are inverted with respect to the reversible wing  50 . The moldboard retainer strip  142 , the wearstrip  148 , the mounting hardware  154 , the support shoe mounting hardware  160  and the rear scraper  168  are then removably secured to the frame  52  in the manner described above, using the apertures provided therein.  
      Turning next to  FIGS. 6 and 7 , the center section  48  of the snow plow blade assembly  46  of the present invention is described. The center section  48  includes a tower indicated generally at  174  that is a hollow, substantially triangular elongated member formed from a front plate indicated generally at  176  which is the front side of the tower  174  and two angled side plates indicated generally at  178  and  180  which angle away from the front plate  176 , towards the rear of the snow plow. Together the front plate  176  and the side plates  178  and  180  form three corner edges  182 ,  184  and  186  of the tower  174 . The tower  174  has a top indicated generally at  188  and a bottom indicated generally at  190 .  
      The tower  174  is preferably constructed of steel, and is constructed by welding the front plate  176  and the side plates  178  and  180  together at the corner edges  182 ,  184  and  186 . However, any rigid metal material known to those skilled in the art may be used to construct the tower  174 . Further, the tower  174  may be constructed of a triangular member that requires no assembly.  
      The internal perimeter of the tower  174  is reinforced with four reinforcing plates  192  that are spaced apart along the length of the tower  174  from the top  188  to the bottom  190 . Reinforcing plates  192  are provided to supplement the structural strength of the tower  174 . The reinforcing plates  192  are preferably constructed of steel and welded to the tower  174 .  
      Referring next to  FIGS. 8 through 10 , in addition to  FIGS. 6 and 7 , the top of the front plate  176  includes a forwardly projecting angled portion  194  that extends upwardly toward the front side of the snow plow. The angled portion  194  includes apertures  196 . The front plate  176  also includes two tabs  198  located on either side of the front plate  176  near each of the corner edges  182  and  184 . The tabs  198  project slightly above the top of the side plates  178  and  180  and each include an aperture  200  that will be used to secure the reversible wings  50  and  51  to the center section  48 , as will be described further below.  
      The edges of the front plate  174  angle slightly rearwardly to the corner edges  182  and  184 , forming mounting surfaces  202  and  204  located near each of the corner edges  182  and  184  of the tower  174 , respectively (as best illustrated in  FIGS. 7 and 9 ). Each mounting surface  202  and  204  extend from the top  188  to the bottom  190  of the tower  174 .  
      Mounting surface  202  contains a plurality of hollow, tubular hinge pieces  206  secured thereto. Preferably, four tubular hinge pieces  206  are used in the present invention. However, any number of tubular hinge pieces  206  may be used. The tubular hinge pieces  206  are mounted spaced-apart in axial alignment on the mounting surface  202  of the tower  174  from a position just below the tab  198  near the top  188  of the tower  174  to the bottom  190  of the tower  174 . The tubular hinge pieces  206  are arranged in a manner that will permit the tubular hinge pieces to interfit with the tubular hinge pieces  134  on the reversible wing  50 . The tubular hinge pieces  206  are preferably constructed of steel and are secured to the mounting surface  202  by welding.  
      Likewise, mounting surface  204  contains a plurality of hollow, tubular hinge pieces  208  secured thereto. Preferably, four tubular hinge pieces  208  are used in the present invention. However, any number of tubular hinge pieces  208  may be used. The tubular hinge pieces  208  are mounted spaced-apart in axial alignment on the mounting surface  204  of the tower  174  from a position just below the tab  198  near the top  188  of the tower  174  to the bottom  190  of the tower  174 . The tubular hinge pieces  208  are arranged in a manner that will permit the tubular hinge pieces to interfit with the tubular hinge pieces  134  on the reversible wing  51 . The tubular hinge pieces  208  are preferably constructed of steel and are secured to the mounting surface  204  by welding.  
      A trip spring retainer plate  210  is mounted near the top  188  of the tower  174  and extends outwardly from the sides  178  and  180 . Preferably, the trip spring retainer plate  210  is constructed of steel and is secured to the tower  174  by welding. Two apertures  212  are formed within the trip spring retainer plate  210  towards the rear portion of the trip spring retainer plate  210 . As best illustrated in  FIG. 10 , two spring retainer eye bolts  214  are secured to the trip spring retainer plate  210 . Each eye bolt passes through one of the apertures  212  and is retained in place by a nut  216 .  
      Referring next to  FIG. 11 , in addition to  FIGS. 6 through 10 , a blade mounting plate  218  is attached to the front plate  176  at the bottom  190  of the tower  174 . The blade mounting plate  218  extends from the corner edge  182  to the corner edge  184  and angles forwardly towards the front of the snow plow. The blade mounting plate  218  is preferably constructed from steel and welded into place on the tower  174 . The blade mounting plate  218  includes two sets of apertures  220  and  222 , a first set of three apertures  220  for securing a center blade  224  thereto. The second set of two apertures  222  are provided for securing a cushion block  226  thereto.  
      The center blade  224  is substantially trapezoidal in shape, having a top portion that is narrower than the bottom portion, as illustrated in  FIGS. 9 and 10 . The center blade  224  is wider than the tower  174  is its bottom portion in order to prevent snow from getting past the snow plow in any configuration of the reversible wings  50 ,  51 . The center blade  224  contains a plurality of apertures matching the pattern of the apertures  220  formed in blade mounting plate  218 .  
      A securing section  228  containing apertures  230  matching the pattern of the apertures  220  formed in blade mounting plate  218  removably secures the center blade  224  to the front side of the blade mounting plate  218 . Bolts  231  passing through the apertures  230  in the securing section  228 , the apertures in the center blade and the apertures  220  in the blade mounting plate  218  are used to retain the center blade  224  onto the tower  174 , as illustrated in  FIG. 8 . The center blade  224  is preferably constructed of rubber, urethane, or a rubberized material. However, the center blade  224  can alternatively be a steel material, a polycarbonate material, thermoplastic material or any other suitable material known to those skilled in the art.  
      The center blade  224  will be mounted with its bottom edge angled forwardly with respect to the ground at angle of between approximately zero and forty-five degrees, with between approximately fifteen and thirty degrees being preferred, and an angle of approximately twenty-five degrees being most preferred.  
      The cushion block  226  is provided to absorb the impact of the plow blade as it moves between its limits, i.e. when the blade trips during an encounter with an object as will be described in more detail herein. The cushion block  226  is generally rectangular in shape and has apertures matching the pattern of the apertures  222  formed in blade mounting plate  218  (apertures not visible in the figures). The cushion block  226  is secured to the rear side of the blade mounting plate  218  using a smaller reinforcing plate  234  also having apertures  236  matching the pattern of the apertures  222  formed in blade mounting plate  218 . Bolts  238  passing through the apertures  222  in the blade mounting plate  218 , the apertures in the cushion block  226  and the apertures  236  in the reinforcing plate  234  and nuts  240  are used to removably secure the cushion block  226  in place on the tower  174 . In addition, washers may be used to ensure that the cushion block  226  and reinforcing plate  234  are tightly secured to the blade mounting plate  218 .  
      As best illustrated in  FIG. 10 , an opening  242  is formed within in the tower  174  wherein portion of each of the side plates  178  and  180  is removed therefrom, providing access to the rear side of the front plate  176 . A substantially square stop plate  280  is located just underneath the corner edge  186  where the side plates  178  and  180  meet, at the top of the opening  242 . The stop plate  280  is preferably constructed of steel and welded to the tower  174 .  
      Trip plates  252  and  254  are vertically located on the rear side of the tower  174 . Trip plates are identical to each other and each includes a triangular top portion  256 , a middle portion  260  and a bottom portion  264  (as shown in  FIG. 8  for the trip plate  252 . Trip plate  254 , not shown, has a corresponding top portion  256 , a middle portion  260  and a bottom portion  264 ). The trip plate  252  is preferably made of steel and is welded at its triangular top portion  256  and middle portion  260  to the side plate  178  and is welded at its bottom portion  264  to the blade mounting plate  218 . Likewise, the trip plate  254  is preferably made of steel and is welded at its triangular top portion  256  and middle portion  260  to the side plate  180  and is welded at its bottom portion  264  to the blade mounting plate  218 .  
      As best illustrated in  FIGS. 8 and 10 , the trip plates  252  and  254  each contain an aperture  267  and  269 , respectively. The apertures  267  and  269  are located in horizontal coaxial alignment with each other on the trip plates  252  and  254  such that a pin or another elongated member may be passed through both apertures  267  and  269 .  
      A U-shaped cylinder mount bracket  268  is mounted on trip plate  252  for securing the end of a hydraulic cylinder (or other mechanism for moving the reversible wings  50 ,  51  into position). Each leg of the U-shaped cylinder mount bracket  268  includes an aperture  270 . The apertures  270  are in vertical coaxial alignment with each other so as to permit a pin  272  to pass therethrough. Likewise, a U-shaped cylinder mount bracket  274  is mounted on trip plate  254  for securing the end of a hydraulic cylinder (or other mechanism for moving the reversible wings  50 ,  51  into position). Each leg of the U-shaped cylinder mount bracket  274  includes an aperture  276 . The apertures  276  are in vertical coaxial alignment with each other so as to permit a pin  278  to pass therethrough.  
      Turning next to  FIGS. 12 through 15 , an intermediate section  282  is illustrated. The intermediate section  282  has a top side indicated generally at  284 , a bottom side indicated generally at  286 , a front side indicated generally at  288 , which will face towards the tower  174 , and a rear side indicated generally at  290 , which will face the snow plow vehicle.  
      The intermediate section  282  includes a top plate  292  and a bottom plate  294 . The top plate  292  includes a substantially square aperture  296  and three securing apertures  298  for securing a cushion thereto, which will be described in further detail with reference to  FIGS. 34 and 35  herein. The top plate  292  also contains a larger, round aperture  300  for securing a support shoe or another support mechanism to the intermediate section  282 , which will be described with reference to  FIGS. 32 through 35  also herein.  
      The bottom plate  294  is identical in configuration as the top plate  292  and, accordingly, contains a substantially square aperture  302  and three securing apertures  304  for securing a cushion thereto, which will be described in further detail with reference to  FIGS. 32 through 35  herein. The bottom plate  294  also contains a larger, round aperture  306  for securing a support shoe or another support mechanism to the intermediate section  282 , which will also be described with reference to  FIGS. 32 through 35  herein.  
      The intermediate section  282  is arranged and configured such that the top and bottom plates  292  and  294  are positioned horizontally parallel to each other with the square apertures  296  and  302 , securing apertures  298  and  304 , and round apertures  300  and  306  substantially aligned. Both the top and bottom plates  292  and  294  are preferably constructed of steel.  
      Referring next to  FIGS. 13 through 15 , the top and bottom plates  292  and  294  are secured together by first and second sides  308  and  310 , respectively. The first side  308  includes a first circular aperture  312  located near the rear side  290  of the intermediate section  282  and a second circular aperture  314  located near the front side  288  of the intermediate section  282 . The first side  308  also includes an upwardly projecting tab  316  including an aperture  318  for securing the end of a trip spring thereto. The first side  308  also contains a downwardly projecting fin  320  located near the front side  288  of the intermediate section  282 .  
      The second side  310  of the intermediate section  282  is substantially the mirror image of the first side  308  and thus includes a first circular aperture  322  located near the rear side  290  of the intermediate section  282  and a second circular aperture  324  located near the front side  288  of the intermediate section  282 . The second side  310  also includes an upwardly projecting tab  326  including an aperture  328  for securing the end of the trip spring thereto. The second side  310  also contains a downwardly projecting fin  330  located near the front side  288  of the intermediate section  282 .  
      The first and second sides  308  and  310  are positioned such that the first circular apertures  312  and  322 , the second circular apertures  314  and  324 , the tabs  316  and  326 , and the fins  320  and  330  are vertically aligned, as shown in  FIGS. 12, 13  and  15 . The first and second sides  308  and  310  are preferably constructed of steel and welded into position.  
      The intermediate section  282  also includes a hollow, pivot tube  332  having ends  334  and  336 . The pivot tube  332  extends through the second circular aperture  314  in the first side  308  of the intermediate section  282  and through the second circular aperture  324  in the second side  310  of the intermediate section  282 , with ends  334  and  336  extending out from the first and second sides  308  and  310 , respectively. The pivot tube  332  may optionally include a grease fitting  338  that will permit lubrication of the pivoting element when the snow plow blade is completely assembled, as will be described in more detail herein. The pivot tube  332  is preferably steel and is secured in place on the intermediate section  282  by welding.  
      Turning next to  FIGS. 16 through 21 , a main frame  344  of the snow plow of the present invention is illustrated. The main frame  344  will be mounted to the intermediate section  282 , as will be described in detail with respect to  FIGS. 21, 36  and  37 . The main frame  344  has a front end  346  and a rear end  348  and contains right and left sides  350  and  352 , respectively, that are symmetric around an axis running from the front end  346  to the rear end  348  thereof. The main frame  344  tapers from a narrower width at the front end  346  to a wider width at the rear end  348  thereof.  
      The basic shape of the main frame  344  is formed by a top plate  354  and a bottom plate  356 , which are essentially parallel and are spaced apart from each other. There is a large aperture extending through each of the top plate  354  and the bottom plate  356  which resembles an isosceles trapezoid. The top plate  354  and the bottom plate  356  are preferably made of steel.  
      Portions of all four sides of the top plate  354 , substantially around the perimeter of the main frame  344 , are bent downwardly at a ninety degree angle to extend to the top of the bottom plate  356  (as illustrated in  FIGS. 16 and 18  through  21 ). For example, as best illustrated in  FIG. 16 , the top plate  354  is bent downwardly and welded to the top of the bottom plate  356  forming the left side  352  of the main frame  344 . The front end  346 , the rear end  348  and the right side  350  are similarly formed from the top plate  354  and are welded to the top side of the bottom plate  356 , respectively.  
      Mounted between the sides of the top plate  354  and the bottom plate  356  and extending rearwardly from the rear end  348  of the main frame  344  are lugs  358  and  360 . The lugs  358  and  360  are preferably made of steel and are welded onto the sides of the top plate  354  and the bottom plate  356 . The portion of the lug  358  which extends upwardly and rearwardly from the top plate  354  and the bottom plate  356  has an aperture  362  extending therethrough, and the portion of the lug  360  which extends rearwardly from the top plate  354  and the bottom plate  356  has an aperture  364  extending therethrough.  
      Mounted adjacent to each of the lugs  358  and  360  are lug gusset plates  366  and  368  for adding additional support to lugs  358  and  360 . The lug gusset plates  366  and  368  are preferably made of steel and each are welded to the top plate  354  and to the lugs  358  and  360 , respectively.  
      Mounted at substantially the center of the rear end  348  of the top plate  354  and the bottom plate  356  are two lift cylinder mounts  370  and  372 . The lift cylinder mounts  370  and  372  are parallel both to each other and to the plane which divides the main frame  344  into left and right sides thereof. The lift cylinder mounts  370  and  372  each extend from slots  374  and  376 , respectively, in the bottom plate  356  to the slots  378  and  380 , respectively, in the top plate  354 . The lift cylinder mounts  370  and  372  are also preferably made of steel and their ends are welded into the slots  374  and  376 , respectively, in the bottom plate  356  and the slots  378  and  380 , respectively, in the top plate  354 . The lift cylinder mounts  370  and  372  each have an aperture  382  and  384 , respectively, located therein which are coaxial to each other.  
      An inner support plate  386  is mounted between the top plate  354  and the bottom plate  356  near the top of the aperture in the main frame  344 , near the front end  346 . Located at the top of the trapezoidal aperture in the main frame  344 , are two spaced-apart pivot mount plates  388  and  390 . The pivot mount plates  388  and  390  are also preferably made of steel and are welded onto the inner support plate  386 , the portion of the top plate  354  adjacent thereto, and the portion of the bottom plate  356  adjacent thereto. The pivot mount plates  388  and  390  are mounted on opposite sides of the centerline of the main frame  344 , and extend rearwardly and upwardly from the inner support plate  386 , and extend downward from the bottom plate  356 . Located near the rearmost and uppermost ends of the pivot mount plates  388  and  390  are apertures  392  and  394 , respectively, which are coaxial to each other.  
      As best illustrated in  FIGS. 18 through 21 , a platform  396  is mounted on to the topmost edges of the pivot mount plates  388  and  390  for securing hydraulic and/or electrical equipment to the main frame  344 . The platform  396  is preferably constructed of steel. To secure the platform  396  to the main frame  344 , a portion of each of the pivot mount plates  388  and  390  extends through slots in the platform  396  and the pivot mount plates  388  and  390  are welded therein.  
      Hinge brackets  402  and  404  are mounted near the front end  346  on each of the left and right sides  352  and  350  of the main frame  344 . Hinge brackets  402  and  404  are secured to the ends of the left and right sides  352  and  350 , respectively, and extend beyond the front end  346  of the top and bottom plates  354  and  356 . The hinge brackets  402  and  404  are also preferably made of steel and are preferably secured in place onto the main frame  344  by welding.  
      The hinge brackets  402  and  404  are substantially L-shaped having a rear portion that extends outwardly from left and sides  352  and  350 , respectively, of the main frame  344  and that curves inwardly near a front portion thereof, as best illustrated in  FIG. 17 . The rear portion of each hinge bracket  402  and  404  extends above the top plate  354  and contains an aperture  406  and  408 , respectively. The rear portion of each hinge bracket  402  and  404  also extends below the bottom plate  356  and contains an aperture  410  and  412 , respectively. Nuts  414 ,  416 ,  418  and  420  are welded onto the apertures  406 ,  408 ,  410 , and  412 , respectively, so that the opening in each nut is coaxial with each respective aperture. The front portion of each hinge bracket  402  and  404  contain apertures  422  and  424 , respectively, that are coaxial with each other.  
      A hollow tube  426  extends from the hinge bracket  402  to the hinge bracket  404  having an end  428  that extends through the aperture  422  in the hinge bracket  402  and an end  430  that extends through the aperture  424  in the hinge bracket  404 .  
      Referring next to  FIG. 22 , a lift bar  432  is illustrated which forms part of the hitch mechanism of the snow plow. The lift bar  432  has two lift bar support members  434  and  436 , which are located on the left and right sides, respectively, of the lift bar  432 . Each of the lift bar support members  434  and  436  has a configuration consisting of three segments: rear mounting supports  438  and  440 , respectively, which extend upward vertically; central support arms  442  and  444 , respectively, which extend forwardly and upwardly from the top of the rear mounting supports  438  and  440 , respectively; and front light bar supports  446  and  448 , respectively, which extend upwardly from the forwardmost and upwardmost ends of the central support arms  442  and  444 , respectively. The lift bar support members  434  and  436  are preferably made of steel plate.  
      Extending inwardly from the rear sides of rear mounting supports  438  and  440  are segments of angled stock  450  and  452 , respectively. It should be noted that the angle defined by each of the segments of angled stock  450  and  452  is less than ninety degrees, as, for example, approximately seventy degrees. The reason for this angle will become apparent below in conjunction with the discussion of  FIGS. 27 and 28 . The angled stock segments  450  and  452  are also preferably made of steel, and are welded onto rear mounting supports  438  and  440 , respectively, so that the rear mounting supports  438  and  440  and the angled stock segments  450  and  452  together form vertically-oriented channels which are essentially U-shaped. Referring for the moment to  FIG. 16  in addition to  FIG. 22 , the space between the rear mounting support  438  and the angled stock segment  450  of the lift bar  432  is designed to admit the lug  358  of the main frame  344  with space between the lug  358  and the inside of the angled stock segment  450 , and similarly the space between the angled stock segment  452 , and the rear mounting support  440  of the lift bar  432  is designed to admit the lug  360  of the main frame  344  with space between the lug  360  and the inside of the angled stock segment  452 .  
      Referring again solely to  FIG. 22 , a rectangular reinforcing segment  454  (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support  438  and the angled stock segment  450 , and is welded to the bottoms of the rear mounting support  438  and the angled stock segment  450 . Similarly, a rectangular reinforcing segment  456  (preferably also made of steel) is located at the bottom of the U-shaped channel formed by the rear mounting support  440  and the angled stock segment  452 , and is welded to the bottoms of the rear mounting support  440  and the angled stock segment  452 .  
      Not illustrated in the figures but used to reinforce the construction of the lift bar  432  are two additional rectangular reinforcing segments which are respectively located above the reinforcing segments  454  and  456 . On the left side of the lift bar  432 , the first of these additional reinforcing segments (preferably also made of steel) is located near the top of the U-shaped channel formed by the rear mounting support  438  and the angled stock segment  450 , and is welded to the tops of the rear mounting support  438  and the angled stock segment  450 . Similarly, the other of these reinforcing segments (preferably also made of steel) is located at near the top of the U-shaped channel formed by the rear mounting support  440  and the angled stock segment  452 , and is welded to the tops of the rear mounting support  440  and the angled stock segment  452 .  
      Extending between the lift bar support members  434  and  436  are a larger diameter hollow round upper pin support tube  458  and a smaller diameter round light bar brace  460 . The upper pin support tube  458  and the light bar brace  460  are both also preferably made of steel. One end of the upper pin support tube  458  extends through an aperture  462  located in an intermediate position in the central support arm  442  of the lift bar support member  434 , and the other end of the upper pin support tube  458  extends through an aperture  464  located in an intermediate position in the central support arm  444  of the lift bar support member  436 . The ends of the upper pin support tube  458  are welded onto the central support arms  442  and  444 . One end of the light bar brace  460  is welded onto the lift bar support member  434  at the intersection of the central support arm  442  and the light bar support  446 , and the other end of the light bar brace  460  is welded onto the lift bar support member  436  at the intersection of the central support arm  444  and the light bar support  448 .  
      Two upper pin hanger plates  466  and  468  are mounted on the upper pin support tube  458  in spaced-apart fashion near the middle of the upper pin support tube  458 . The upper pin hanger plates  466  and  468  have apertures  470  and  472 , respectively, extending therethrough near one end thereof, and the upper pin support tube  458  extends through these apertures  470  and  472 . The upper pin hanger plates  466  and  468  are both also preferably made of steel, and are welded onto the upper pin support tube  458  in a manner whereby they are projecting forwardly. A tubular upper pin  474  extends through apertures  476  and  478  in the upper pin hanger plates  466  and  468 , respectively, near the other end thereof. The upper pin  474  is also preferably made of steel, and is welded onto the upper pin hanger plates  466  and  468 .  
      Located in the rear mounting support  438 , the angled stock segment  450 , the angled stock segment  452 , and the rear mounting support  440  near the bottoms thereof are apertures  480 ,  482 ,  484 , and  486 , respectively, which are aligned with each other and which together define a pivot axis about which the lift bar  432  will pivot when it is mounted onto the main frame  344  (illustrated in  FIG. 26 ). Located in the rear mounting support  438 , the angled stock segment  450 , the angled stock segment  452 , and the rear mounting support  440  nearer the tops thereof than the bottoms thereof are apertures  488 ,  490  (not shown in  FIG. 22 ),  492 , and  494 , which are also aligned with each other.  
      The apertures  488  and  490  define a first location into which a retaining pin (not shown in  FIG. 22 ) will be placed to mount the snow plow of the present invention onto a truck, and the apertures  492  and  494  define a second location into which another retaining pin (not shown in  FIG. 22 ) will be placed to mount the snow plow of the present invention onto the truck. Located in the light bar support  446  are three apertures  496 , and located in the light bar support  448  are three apertures  498 . The apertures  496  and  498  will be used to mount a light bar (not illustrated in  FIG. 22 ) onto the lift bar  432 .  
      Referring now to  FIG. 23 , a hitch frame nose piece  500  which will be mounted onto a truck under the front bumper (not illustrated in  FIG. 23 ) thereof is illustrated. The hitch frame nose piece  500  has a square hitch frame tube  502  which is horizontally oriented. Four hitch brackets  504 ,  506 ,  508 , and  510  are mounted on the square hitch frame tube  502  in spaced-apart pairs located nearer the ends of the square hitch frame tube  502  than the center thereof. The hitch brackets  504 ,  506 ,  508 , and  510  have square apertures  512 ,  514 ,  516 , and  518 , respectively, extending therethrough to receive therein the square hitch frame tube  502 . Both the square hitch frame tube  502  and the hitch brackets  504 ,  506 ,  508 , and  510  are preferably made of steel, and the hitch brackets  504 ,  506 ,  508 , and  510  are welded onto the square hitch frame tube  502 .  
      Referring for the moment to  FIG. 22  in addition to  FIG. 23 , the space between the hitch bracket  504  and the hitch bracket  506  of the hitch frame nose piece  500  is designed to admit the rear mounting support  438  and the angled stock segment  450  of the lift bar  432 , and similarly the space between the hitch bracket  508  and the hitch bracket  510  of the hitch frame nose piece  500  is designed to admit the angled stock segment  452  and the rear mounting support  440  of the lift bar  434 . The hitch brackets  504 ,  506 ,  508 , and  510  have rectangular notches  520 ,  522 ,  524 ,  526 , respectively, cut into the front sides thereof.  
      Located in the hitch brackets  504 ,  306 ,  508 , and  510  in the bottoms of the rectangular notches  520 ,  522 ,  524 , and  526 , respectively, are slots  528 ,  530 ,  532 , and  534 , respectively. The slots  528 ,  530 ,  532 , and  534  have rounded bottoms, and are axially aligned. Also located in the hitch brackets  504 ,  506 ,  508 , and  510  above the tops of the rectangular notches  520 ,  522 ,  524 , and  526 , respectively, are apertures  536 ,  538 ,  540 , and  542 , respectively. The apertures  536 ,  538 ,  540 , and  542  are also axially aligned.  
      Unlike the hitch brackets  506  and  508  which are flat, the hitch brackets  504  and  510  have their forward-most portions flanged outwardly to act as guides to direct the lift bar  432  (illustrated in  FIG. 22 ) into engagement with the hitch frame nose piece  500 . Thus, the portions of the hitch brackets  504  and  510  at the front of the rectangular notches  520  and  526 , respectively, extend outwardly, both on the top of the rectangular notches  520  and  526  and on the bottom of the rectangular notches  520  and  526 . It should be noted that, if desired, the hitch brackets  504  and  510  may also be flat. The ramifications of having them flat instead of flanged will eliminate the utility of the left and right sides of the lift bar  432 .  
      The respective ends of the square hitch frame tube  502  are mounted onto mounting plates  544  and  546 . The mounting plates  544  and  546  are also preferably made of steel, and the ends of the square hitch frame tube  502  are welded onto the mounting plates  544  and  546 . Located in the mounting plates  544  and  546  are a plurality of apertures  548  and  550 , respectively, which will be used to mount the hitch frame nose piece  500  onto the frame of a truck (not shown in  FIG. 23 ) using mounting brackets (not shown in  FIG. 23 ) in a manner which is conventional.  
      Referring next to  FIG. 24 , a bellcrank  560  is illustrated. The bellcrank  560  has parallel, spaced apart triangular pivot plates  562  and  564 . One of the sides of the triangle is shorter than the other two in each of the pivot plates  562  and  564 . A gusset plate  566  is mounted between the pivot plates  562  and  564  with one side thereof near the shortest side of the triangle to support the pivot plates  562  and  564  in their spaced-apart configuration. In the preferred embodiment, both the pivot plates  562  and  564  and the gusset plate  566  are made of steel, and are welded together.  
      The pivot plates  562  and  564  have apertures  570  and  572 , respectively, located therein near a first corner of the triangle which will be used to mount the bellcrank  560  for pivotal movement from the apertures  392  and  394  of the pivot mount plates  388  and  390 , respectively (illustrated in  FIG. 16 ). The pivot plates  562  and  564  have apertures  574  and  576 , respectively, located therein near a second corner of the triangle which will be connected via the element to be discussed in  FIG. 25  below to drive the upper pin  474  of the lift bar  432  (illustrated in  FIG. 22 ). The pivot plates  562  and  564  have apertures  578  and  580  (not shown in  FIG. 24 ), respectively, located therein near the third corner of the triangle will be connected to a hydraulic cylinder (not shown in  FIG. 24 ). The short side of the triangle is between the first and third corners of the triangle. The side of the gusset plate  566  adjacent this short side will act as a lift stop to limit pivotal movement of the gusset plate  566  when this side of the gusset plate  566  contacts the pivot mount plates  388  and  390  (illustrated in  FIG. 16 ).  
      Referring now to  FIG. 25 , a lift link  590  is illustrated. The lift link  590  has parallel, spaced apart arms  592  and  594 . A gusset plate  596  is mounted between the arms  592  and  594  in their spaced-apart configuration. The side of the gusset plate  596  which is oriented toward one end of the arms  592  and  594  has a notch  598  cut therein. In the preferred embodiment, both the arms  592  and  594  and the gusset plate  596  are made of steel, and are welded together. The one end of the arms  592  and  594  have apertures  600  and  602 , respectively, located therein, and the other ends of arms  592  and  594  have apertures  604  and  606 , respectively, located therein.  
      Referring next to  FIG. 26 , the linkage used to attach the snow plow of the present invention to the hitch frame nose piece  500  is illustrated. The components which are linked together are the main frame  344 , the lift bar  432 , the bellcrank  560 , and the lift link  590 . Accordingly, reference may also be had to  FIGS. 16 and 22  through  26  as well as to  FIGS. 27 and 28  in the following description of the interconnection of these components. The lift bar  432  is pivotally mounted on the main frame  344  using two pins  608  and  610  (the pin  610  is not shown in  FIGS. 16, 27  and  28 ) which are each of a length longer than distance between the opposite-facing sides of the pairs of the hitch brackets  504  and  506 , or  508  and  510  (illustrated in  FIG. 28 ). The pins  608  and  610  are preferably made of steel.  
      In the preferred embodiment, a hollow cylindrical collar  612  (shown in  FIGS. 27 and 28 ) having a setscrew  614  (also shown in  FIGS. 27 and 28 ) is used with the pin  608  as a spacer. A similar collar which a setscrew (not shown in the drawings) is used with the pin  610  as a spacer. The collar  612  will be located intermediate the lug  358  on the plow main frame  344  and the angled stock segment  450  on the lift bar  432 . The setscrew  614  on the collar  612  may be used to lock the collar  612  in place on the pin  608 . The other collar will be located intermediate the lug  360  on the main frame  344  and the angled stock segment  452  on the lift bar  432 , with a setscrew in that collar being used to lock that collar in place on the pin  610 .  
      The pin  608  will thus extend sequentially through the aperture  480  in the rear mounting support  438  of the lift bar  432 , the aperture  362  in the lug  358  of the main frame  344 , the collar  612 , and the aperture  482  in the angled stock segment  450  of the lift bar  432 . The pin  608  will be retained in place by the setscrew  614  on the collar  612 , which will contact the pin  608  when it is screwed into the collar. Approximately equal lengths of the pin  408  extend outwardly beyond the rear mounting support  438  and the angled stock segment  450  at each end of the pin  608 . Alternately, the pin  608  may be welded in place on the rear mounting support  438  and the angled stock segment  450  of the lift bar  432 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin  608  at locations which correspond to the ends of the collar.  
      Likewise, the pin  610  will thus extend sequentially through the aperture  484  in the angled stock segment  452  of the lift bar  432 , the other collar, the aperture  364  in the lug  360  of the main frame  344 , and the aperture  486  in the rear mounting support  440  of the lift bar  432 . The pin  610  will be retained in place by the setscrew on the collar, which will contact the pin  610  when it is screwed into the collar. Equal lengths of the pin  610  extend outwardly beyond the angled stock segment  452  and the rear mounting support  440  at each end of the pin  610 . Alternately, the pin  610  may be welded in place on the angled stock segment  452  and the rear mounting support  440  of the lift bar  432 , or C-clips (not shown herein) could be installed in annular groves (not shown herein) in the pin  610  at locations which correspond to the ends of the collar.  
      It will thus be appreciated by those skilled in the art that the lift bar  432  is pivotally mounted onto the main frame  344  using the pins  608  and  610 . When the snow plow of the present invention is mounted onto a vehicle using the hitch frame nose piece  500 , the ends of the pins  608  and  610  will be received in the pairs of slots  528  and  530 , and  532  and  534  in the hitch frame nose piece  300  (illustrated in  FIG. 23 ). Thus, the pins  608  and  610  function both to pivotally mount the lift bar  432  onto the main frame  344 , and to help to mount the snow plow onto the hitch frame nose piece  500 .  
      The bellcrank  560  is pivotally mounted on the main frame  344  using two bolts  620  and two nuts  622 . The pivot plates  562  and  564  of the bellcrank  560  will fit outside of the pivot mount plates  388  and  390  of the main frame  344 , respectively. One of the bolts  620  will extend through the aperture  392  in the pivot mount plate  388  of the main frame  344  and the aperture  570  in the pivot plate  562  of the bellcrank  560 , and one of the nuts  622  will be mounted on that bolt  620  to retain it in place. The other one of the bolts  620  will extend through the aperture  394  in the pivot mount plate  390  of the main frame  344  and the aperture  572  in the pivot plate  564  of the bellcrank  560 , and the other one of the nuts  622  will be mounted on that bolt  620  to retain it in place.  
      The bolts  620  allow the bellcrank  560  to pivot on the main frame  344 . In the preferred embodiment, a spacer and two washers (not shown) may be used with each of the bolts  620 , the spacer going through the apertures in the parts being pivotally joined and being longer than the combined thickness of the apertures in the parts, and a washer being located on either end of the spacer to facilitate free rotation of parts, here movement of the bellcrank  560  with reference to the main frame  344 . It will be understood by those skilled in the art that a spacer and two washers will preferably be used at other points of relative movement between two elements of linkage of the snow plow described herein, although the spacer and two washers will not be specifically mentioned in conjunction with each of these pivoting connections made between two elements using a bolt. In addition, it will be understood by those skilled in the art that a pin retained by a cotter pin (not shown herein) could be used instead of a bolt and nut in many of the applications for a fastener used in the linkage discussed herein.  
      A hydraulic lift cylinder  624  is mounted at one end to the cylinder mounts  370  and  372  of the main frame  344  using a bolt  626  which extends through the aperture  382  in the cylinder mount  370  and the aperture  384  in the cylinder mount  372 , with a nut  628  being used to retain the bolt  626  in place. The other end of the hydraulic cylinder  624  drives the third corner of the triangular pivot plates  562  and  564  of the bellcrank  560 , with a bolt  630  extending between the aperture  578  in the pivot plate  562  of the bellcrank  560  and the aperture  580  in the pivot plate  564  of the bellcrank  560 . A nut  632  is used to retain the bolt  630  in place. The bolts  626  and  630  allow the hydraulic cylinder  624  to move as it drives the bellcrank  560 . Spacers (not shown herein) may be used on each side of the other end of the hydraulic cylinder  624  on the insides of the pivot plates  562  and  564  to center the hydraulic cylinder  624 .  
      The lift link  590  is used to connect the bellcrank  560  to pivot the lift bar  432 . A bolt  634  is used to connect the lift link  590  to the lift bar  344 , with the bolt  634  extending sequentially through the aperture  604  in the arm  592  of the lift link  590 , the upper pin  474  from the end extending through the upper pin hanger plate  466  to the end extending through the upper pin hanger plate  468  of the lift bar  432 , and the aperture  606  in the arm  594  of the lift link  590 . A nut  636  is used to retain the bolt  634  in place. The bolt  634  allows the lift link  590  to pivot on the lift bar  432 , and a spacer and two washers may also be used as mentioned hereinabove.  
      The second corner of the triangle formed by the pivot plates  562  and  564  of the bellcrank  560  drives the ends of the arms  592  and  594  of the lift link  590  which are not connected to the lift bar  432 . Two bolts  638  are used to connect the bellcrank  560  to the lift link  590 , with one of the bolts  638  also being used to mount a stand  640 . The stand  640  is described in U.S. Pat. No. 5,894,688, to Struck et al., which patent is assigned to the assignee of the inventions described herein. U.S. Pat. No. 5,894,688 is hereby incorporated herein by reference.  
      One bolt  638  extends through the aperture  600  in the arm  692  of the lift link  590  and the aperture  574  of the pivot plate  562  of the bellcrank  560 , with a nut  642  being used to retain the first bolt  638  in place, and a spacer and two washers may also be used as mentioned hereinabove. The other bolt  638  (not shown) extends sequentially through an aperture (not shown) in the upper portion of the stand  640 , the aperture  576  of the pivot plate  564  of the bellcrank  560 , and the aperture  602  in the arm  594  of the lift link  590 , with a nut  642  being used to retain the second bolt  638  in place. The second bolt  638  allows the lift link  590  to pivot on the bellcrank  560 , and a spacer and two washers may again be used as mentioned hereinabove. A removable pin (not shown) extending through an aperture near the top of the stand  640  and apertures located in the lift link  590  is used to link the stand  640  with the lift link  590 .  
      The hydraulic cylinder  624  is shown in  FIG. 26  nearly in its fully retracted position. When the hydraulic cylinder  624  is fully extended, it will be appreciated by those skilled in the art that the lift bar  432  will rotate counterclockwise from the position in which it is shown in  FIG. 26 , and the stand  640  will be lowered to engage the ground (not shown) and thereby tend to lift the rear end of the main frame  344  upwardly. It will also be appreciated that once the pins  608  and  610  are in engagement with the slots  528 ,  530 ,  532 , and  534  in the hitch brackets  504 ,  506 ,  508 , and  510 , respectively, of the hitch frame nose piece  500 , the hydraulic cylinder  624  may be used to align the apertures  488 ,  490 ,  492 , and  494  on the lift bar  432  with the apertures  536 ,  538 ,  540 , and  542 , respectively, in the hitch brackets  504 ,  506 ,  508 , and  510 , respectively, of the hitch frame nose piece  500 .  
      Turning next to  FIGS. 29 and 30 , in addition to  FIGS. 1 through 6 , installation of the reversible wings  50  and  51  onto the center section  48  of snow plow of the present invention is illustrated. The reversible wing  50  is arranged on the tower  174  so that the tubular hinge pieces  134  on the reversible wing  50  coaxially interfit with the tubular hinge pieces  206  on the tower  174 , as best illustrated in  FIG. 29 . An elongated pin  650  passes through both the tubular hinge pieces  134  on the reversible wing  50  and the tubular hinge pieces  206  on the tower  174 , forming a pivotable hinge. To secure the pin  650  in place, a bolt  652  passes through the aperture  200  in one of the tabs  198  of the tower  174  and through apertures  654  in the top of the pin  650  and is secured in place by a nut  656 .  
      Likewise, the reversible wing  51  is arranged on the tower  174  so that the tubular hinge pieces  134  on the reversible wing  51  coaxially interfit with the tubular hinge pieces  208  on the tower  174 , as best illustrated in  FIG. 29 . An elongated pin  658  passes through both the tubular hinge pieces  134  on the reversible wing  51  and the tubular hinge pieces  208  on the tower  174 , forming a pivotable hinge. To secure the pin  658  in place, a bolt  660  passes through the aperture  200  in the other tab  198  of the tower  174  and through apertures (not shown in  FIGS. 29 and 30 ) in the top of the pin  658  and is secured in place by a nut (not shown).  
      Thus, it will be apparent to those skilled in the art that the reversible wing  50  is hingedly attached to the tower  174  and can move forward and back accordingly. In addition, in case of damage to either reversible wing  50  or  51 , the reversible wings  50  and  51  are easily removed from the center section  48  by simply removing the nuts and bolts and removing the elongated pins  650  and  658 , respectively. Accordingly, replacement wings are easily mounted to the center section  48  as described above.  
      Turning next to  FIG. 31 , in addition to  FIGS. 1-6  and  29  and  30 , installation of hydraulic swing cylinders  670  and  672  is shown. The swing cylinder  670  is secured at one end to the cylinder mount bracket  268  on the trip plate  252  of the center section  48  using the pin  272  (shown in  FIG. 16 ) which passes consecutively through the top aperture  270  in the cylinder mount bracket  268 , through the end of swing cylinder  670 , and through the bottom aperture  270  of the cylinder mount bracket  268 . The swing cylinder  670  is secured at its other end to the mounting hardware  154  on the reversible wing  50  with a pin  674 .  
      Likewise, the swing cylinder  672  is secured at one end to the cylinder mount bracket  274  on the trip plate  254  of the center section  48  using the pin  278  which passes consecutively through the top aperture  276  in the cylinder mount bracket  274 , through the end of swing cylinder  672 , and through the bottom aperture  276  of the cylinder mount bracket  274  (not shown in  FIG. 31 ). The swing cylinder  672  is secured at its other end to the mounting hardware  154  on the reversible wing  51  with a pin  676 . It will be understood that the pins  272 ,  276 ,  674  and  676  are all retained in place with cotter pins (not shown) as is well known to those skilled in the art. However, any securing mechanism known to those skilled in the art may be used to retain the swing cylinders  670  and  672  in place on the snow plow blade assembly  46 .  
      As best illustrated in  FIGS. 30 and 31 , in addition to  FIGS. 1 through 5 , installation of support shoes  162  onto the support shoe mounting hardware  160  on each reversible wing  50  and  51 , respectively, is shown. The shoes  162  are designed to ride in sliding contact with the surface to be plowed and are particularly useful on gravel or during spring when the ground may not be fully frozen. The shoes are mounted to each reversible wing  50  and  51  using the support shoe mounting hardware  160  thereupon.  
      Each of the shoes  162  includes a post  680  which are received by the support shoe mounting hardware  160 . The shoes  162  are adjusted using a combination of washers and tubular spacers, which are placed on the posts  680  either above or below the support shoe mounting hardware  160  to adjust the height of the shoes  162 . The position of the shoes  162  relative to the reversible wings  50  and  51  (and the plow blade assembly  46 ) may be adjusted to adjust the height of the reversible wings  50  and  51  relative to the surface to be plowed. This allows the degree to which the wearstrip  148  scrapes the surface to be plowed to be controlled. Retaining pins  682  are used on the posts  680  to retain them in the support shoe mounting hardware  160 . The support shoes  162 , however, may be removably attached to the support shoe mounting hardware  160  using any means known to those skilled in the art that will permit easy replacement of the support shoe if it becomes worn or damaged.  
      The shoes  162  are typically made of cast iron. It should be noted that although the rear scraper  168  is not shown in  FIGS. 30 and 31 , it can optionally be used with the shoes  162  in place, so long as the support shoe mounting hardware  160  extends sufficiently back on the reversible wings  50  and  51  to clear the rear scraper  168 .  
      Referring next to  FIGS. 32 through 33 , in addition to  FIGS. 6, 13 ,  15  and  29  through  31 , assembly of the tower  174  and intermediate section  282  is illustrated. The pivot tube  332  of the intermediate section  282  is inserted between the trip plates  252  and  254  of the tower  174 , with the pivot tube  332  being brought into alignment with the apertures  262  and  269  of the trip plates  252  and  254  of the tower  174 . An elongated pivot member  686  is inserted sequentially through the aperture  267  in the trip plate  252 , the pivot tube  332  of the intermediate section  282  and the aperture  269  in the trip plate  254 , as best shown in  FIG. 13 . Each end of the elongated pivot member  686  can be secured in position using a locking pin  688 , or other similar locking device. Optionally, washers may also be used. Accordingly, the pivot member  686  permits the tower  174  to pivot with respect to the intermediate section  282 , as will be discussed in more detail in regard to  FIG. 35 .  
      Referring next to  FIGS. 34 and 35 , in addition to  FIGS. 32 and 33 , the intermediate section  282  includes a cushion  690  that is positioned within and projects upwardly from the square aperture  296  on the top plate  292 . The cushion  690  is provided to absorb the impact of the plow blade and tower  174  as it moves between its limits, i.e. when the snow plow blade trips during an encounter with an object. The cushion  690  may be secured into place using the apertures  296  formed in the top plate  292  and bolts (not shown). However, the cushion  690  may be removably secured to the intermediate section  282  using silicone adhesive (or any suitable type of adhesive) or by any mechanical means known to those skilled in the art. For example, an alternative retaining mechanism would be to have the cushion  690  held in place with an interference fit.  
      The intermediate section  282  also includes a support shoe  692 . The shoe  692  will bear at least a portion of the overall weight of the snow plow frame and is designed to ride in sliding contact with the surface to be plowed. The shoe  692  is preferably constructed of cast iron. The shoe  692  is mounted on a post  694  to secure the shoe  692  to the intermediate section  282 . The post  694  of the shoe  692  is inserted consecutively through both the aperture  306  in the bottom plate  294  and through the coaxial aperture  300  in the top plate  292  of the intermediate section  282 .  
      Like the shoes  162  on each reversible wing  50  and  51 , the shoe  692  is adjusted using a combination of washers and tubular spacers, which are placed on the post  694  either below or above the bottom plate  294  and/or top plate  292  to adjust the height of the shoe  301 . The position of the shoe  692  relative to the snow plow blade may be adjusted relative to the surface to be plowed. The shoe  692  is secured in place using a retaining pin  696 . Optionally, washers may also be inserted onto the post  694  to ensure the shoe  692  is tightly secured in place. It will be readily apparent to one skilled in the art that more than one shoe may be located on the intermediate section  282  and such shoes may be located in any position in which it would be convenient to secure a support shoe for support of the snow plow blade. For example, support shoes may be secured to one or both of the first and second sides  308  and  310  of the intermediate section  282  for adding additional support to the snow plow blade assembly  46 .  
      Trip springs  700  and  702  are connected at one end to the eyebolts  214  on the tower  174  and to the tabs  316  and  326  on the intermediate section  282 , respectively. The trip springs  700  and  702  will be used to bias the tower  174  and the reversible wings  50  and  51  into a trip return position and to resist movement of the tower  174  and the reversible wings  50  and  51  into the tripped position. Thus, the intermediate section  282  is pivotally mounted onto the tower  174  such that the trip springs  700  and  702  permit the tower  174  to move between a tipped forward position (as shown in  FIG. 35 ) when an obstruction is encountered and a release position (as shown in  FIG. 34 ) when the obstruction is removed.  
      Accordingly, when the plow blade encounters and object, the trip springs  700  and  702  permit the top  188  (see  FIG. 6 ) of the tower  174 , and thus the reversible wings  50  and  51  of the snow plow blade assembly  46 , to tip forward to a maximum (or tripped) position where the fins  320  and  330  on the intermediate section  282  contact the cushion block  226  on the tower  174 , as illustrated in  FIG. 35 . Thus, the cushion block  226  not only provides a limit for movement of the snow plow blade, the cushion also absorbs the impact of the obstruction and abrupt movement of the snow plow blade, shielding the snow plow and snow plow vehicle from significant force.  
      As illustrated in  FIG. 34 , when the object no longer interferes with the snow plow blade, the tower  174  tips back into the release position and movement of the tower  174  is limited by the stop plate  280 . The force of the retraction of the trip springs  700  and  702  on the snow plow and the snow plow vehicle is dampened by the cushion  690  which absorbs the impact of the movement of the tower  174  when the stop plate  280  makes contact with the cushion  690 .  
      In the preferred embodiment, the cushions  226  and  690  are made of polyurethane, such as, for example, Quazi formulated methylenebisdiphenyl diisocyanate (MDI) polyester-based 93 durometer (Shore A scale) polyurethane, available commercially from Kryptonics, Inc. under the trademark Kaptane 93 black.  
      Referring next to  FIGS. 36 and 37 , in addition to  FIGS. 12, 16  and  29  through  31 , assembly intermediate section  282  onto the main frame  344  is illustrated. The hollow tube  426  of the main frame  344  is inserted between the top and bottom plates  292  and  294  of the intermediate section  282 , with the hollow tube  426  being brought into alignment with the apertures  312  and  322  in each of the first and second sides  308  and  310 , respectively, of the intermediate section  282 . An elongated pivot member  706  is inserted sequentially through the aperture  312  in the intermediate section  282 , the hollow tube  426  of the main frame  344  and the aperture  322  in the intermediate section  282 . Each end of the elongated pivot member  706  can be secured in position using a locking pin  708 , or other similar locking device. Optionally, washers may also be used. Accordingly, the pivot member  706  permits intermediate section  282  to pivot with respect to the main frame  344  to account for variation in height in the surface of the road and to permit some blade flow during operation of the snow plow.  
      In addition, bolts  710  are provided in each of the apertures  406 ,  408 ,  410 , and  412  of the hinge brackets  402  and  404 , respectively. The bolts  708  are secured into place by nuts  414 ,  416 ,  418  and  420  secured onto the apertures  406 ,  408 ,  410 , and  412 , respectively. The bolts  708  are adjustable to permit movement of the intermediate section  282  and act as limits to such movement.  
      Referring back to  FIGS. 30 and 31  for the moment, support towers  712  and  714 , respectively, are mounted on the light bar supports  446  and  448 , respectively, of the lift bar  432 , and a light support bar  716  is mounted on the top ends of the light support towers  712  and  714 . Lights (not shown herein) would be mounted on the light support bar  716 , in a manner well known to one skilled in the art.  
      Also not shown or discussed herein is the hydraulic system to operate the snow plow, the construction and operation of which is also well known to those skilled in the art. The swing cylinders  670  and  672  are used to pivot reversible wings  50  and  51 , respectively. The hydraulic cylinder  624  (shown in  FIG. 26 ) is used to operate the stand  640  (also shown in  FIG. 26 ) prior to the snow plow being mounted onto a truck, to facilitate the mounting of the snow plow onto the truck (as will become apparent below in conjunction with the discussion of  FIGS. 38 through 42 ), and to raise and lower the plow main frame  344 , the intermediate section  282 , the tower  174  and the reversible wings  50  and  51  after the snow plow has been mounted onto the truck. Preferably, the hydraulic system for the snow plow may be mounted on the platform  396  on the main frame  344 , and if so mounted would have a hydraulic system cover mounted thereupon to protect it (not shown).  
      Turning next to  FIGS. 38 through 42 , and with reference to  FIGS. 27 and 28 , the operation of the mounting system used to mount the snow plow on the hitch frame nose piece  500  is shown. Referring first to  FIGS. 27, 28  and  38 , in conjunction with  FIGS. 16, 22 ,  23 , and  26 , the mechanism used to connect the snow plow to the hitch frame nose piece  500  is shown. In the discussion herein, all references are to the left side of the snow plow and the hitch frame nose piece  500 , but those skilled in the art will understand that the principles thereof are equally applicable to the right side of the snow plow and the hitch frame nose piece  500 .  
      The snow plow is mounted onto the hitch frame nose piece  300  with the plow standing on the stand  640  (shown in  FIG. 10 ). In this position, the pin  608  which extends laterally at the rear of the snow plow on the left side will be at a height such than when the truck having the hitch frame nose piece  500  mounted thereon moves forward, the pin  608  will fit into the rectangular notches  520  and  522  at the front of the hitch brackets  504  and  506 , respectively. The pin  608  is brought fully into the rectangular notches  520  and  522  by moving the truck forward. It will be noted that the flange at the front of the hitch bracket  528  as well as the approximately seventy degree bend in the angled stock segment  450  will assist in guiding the rear mounting support  438  and the angled stock segment  450  of the lift bar  432  into position intermediate the hitch bracket  504  and  506 .  
      A this point, the hydraulic cylinder  624  (shown in  FIG. 26 ) is actuated to begin to retract it to raise the stand  640  (also shown in  FIG. 10 ), causing the pin  608  to drop into the slots  528  and  530  in the hitch brackets  504  and  506 , respectively. By continuing to actuate the hydraulic cylinder  624  to retract it, the lift bar  432  is pivoted to bring the apertures  488  and  490  in the rear mounting support  438  and the angled stock segment  450 , respectively, of the lift bar  432  into alignment with the apertures  536  and  536  in the hitch brackets  504  and  506 , respectively, of the hitch frame nose piece  500 . At this point, a retaining pin  730  having a handle  732  may be inserted sequentially through the aperture  536  in the hitch bracket  504 , the aperture  488  in the rear mounting support  438 , the aperture  490  in the angled stock segment  450 , and the aperture  538  in the hitch bracket  506 . The retaining pin  730  has an aperture  734  extending through near the distal end thereof, and a retaining spring pin  736  is used to retain the retaining pin  730  in place.  
      Turning next to  FIGS. 39 through 42 , and with reference to  FIGS. 27, 28  and  38 , the installation of the snow plow onto the hitch frame nose piece  500  mounted on a truck  800  (shown in phantom lines in  FIG. 42 ) is illustrated. In  FIG. 39 , the snow plow is shown in its stored position, supported on the stand  640 . In this position, the hydraulic cylinder  624  is in its fully extended position, and the rear end of the snow plow is raised. In this position, the pin  610  (not shown in  FIGS. 39 through 42 ) at the right rear of the snow plow will be received by the rectangular notches  524  and  526  (not shown in  FIGS. 39 through 42 ) at the front of the hitch brackets  508  and  510  (not shown in  FIGS. 39 through 42 ), respectively, at the right side of the hitch frame nose piece  500 . Similarly, the pin  608  at the left rear of the snow plow will be received by the rectangular notches  520  and  522  (not shown in  FIGS. 39 through 42 ) at the front of the hitch brackets  504  and  506  (not shown in  FIGS. 39 through 42 ), respectively, at the left side of the hitch frame nose piece  500 . The truck  800  may be driven forward to fully engage the pins  608  and  610  with the hitch frame nose piece  300  as shown in  FIG. 39 .  
      Next, as shown in  FIG. 41 , as the hydraulic cylinder  624  begins to retract, the main frame  344  will lower at the rear end thereof as the stand  640  begins to move upwardly relative to the main frame  344 . This causes the pin  610  (not shown in  FIGS. 39 through 42 ) to drop into the slots  532  and  534  (not shown in  FIG. 41 ) in the hitch brackets  508  and  510  (not shown in  FIG. 41 ), respectively, at the right side of the hitch frame nose piece  500 . Similarly, the pin  608  drops into the slots  528  and  530  (not shown in  FIG. 41 ) in the hitch brackets  504  and  506  (not shown in  FIG. 41 ), respectively, at the left side of the hitch frame nose piece  500 . This initial retraction of the hydraulic cylinder  624  also causes the lift bar  432  to begin to rotate counterclockwise as viewed from the left side of the snow plow, as is evident from the movement of the right light support towers  712  and  714  and the light support bar  716 .  
      As shown in  FIG. 42 , as the hydraulic cylinder  624  continues to retract, the lift bar  432  rotates counterclockwise until the light support towers  712  and  714  are oriented nearly vertically. As this further rotation occurs, the pin  610  (not shown in  FIG. 42 ) remains in the slots  532  and  534  in the hitch brackets  508  and  510 , respectively (none of which are shown in  FIG. 42 ). Similarly, the pin  608  remains in the slots  528  and  530  (not shown in  FIG. 42 ) in the hitch brackets  504  and  506  (not shown in  FIG. 42 ), respectively. On the right side of the lift bar  432  and the hitch frame nose piece  500  (best shown in  FIGS. 22 and 23 ), the apertures  492  and  494  in the angled stock segment  452  and the rear mounting support  440 , respectively, of the lift bar  432  move into engagement with the apertures  540  and  542  in the hitch brackets  508  and  510 , respectively, of the hitch frame nose piece  500 . Likewise, on the left side of the lift bar  432  and the hitch frame nose piece  500  (portions of which are also best shown in  FIGS. 22 and 23 , respectively), the apertures  488  and  490  in the rear mounting support  438  and the angled stock segment  450 , respectively, of the lift bar  432  move into alignment with the apertures  536  and  538  in the hitch brackets  504  and  506 , respectively, of the hitch frame nose piece  500 .  
      At this point, one of the retaining pins  730  is inserted sequentially through the aperture  542  in the hitch bracket  510 , the aperture  494  in the rear mounting support  440 , the aperture  492  in the angled stock segment  452 , and the aperture  540  in the hitch bracket  508  (all of which are best shown in  FIGS. 22 and 23 ). The other one of the retaining pins  730  is inserted sequentially through the aperture  536  in the hitch bracket  504 , the aperture  488  in the rear mounting support  438 , the aperture  490  in the angled stock segment  450 , and the aperture  538  in the hitch bracket  506  (many of which are also best shown in  FIGS. 22 and 23 ). The retaining spring pins  736  are then inserted into the apertures  734  near the distal ends of the retaining pins  730  to retain the retaining pins  730  in place. At this point, the stand  640  may also be moved to a stowed position by disconnecting it from the lift link  590  (by removal of the pin (not shown) and rotating it to the stowed position as is taught in U.S. Pat. No. 5,894,688, which was incorporated by reference above.  
      Turning next to  FIGS. 43   a  and  43   b , operation of the reversible wings  50  and  51  of the present invention is shown. Accordingly, the swing cylinders  670  and  672  may be used to pivot the reversible wings  50  and  51  into any position required by the snow plow operator.  
      It may therefore be appreciated from the above detailed description of the preferred embodiment of the present invention that it teaches a snow plow having reversible wings wherein the snow plow wing frame may be used on either side of a hinged/articulated snow plow. Thus, the reversible wing of the present invention completely eliminates the need for manufacture, assembly and purchase snow plow blade wings specifically designed for either the “left” or the “right” side of the hinged snow plow blade assembly. Accordingly, the reversible wing of the present invention is less expensive to manufacture than conventional hinged snow plow wings.  
      The reversible wing of the present invention is of high strength, yet it is light of weight. Accordingly, the present invention provides a lighter weight snow plow system in which the hydraulic system utilized in positioning each reversible wing is configured in a manner that increases the force and stability of the snow plow blade when in contact with heavy snow, and which requires a lighter hydraulic system. Thus, the snow plow wings, and hence, the snow plow blade can be of a lighter weight construction and yet can effectively remove snow. Such a light snow plow blade construction is light/easier to transport and causes less mechanical stress on the snow plow vehicle than other conventional hinged snow plow blade configurations.  
      The snow plow having reversible wings of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The snow plow having reversible wings of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives of the snow plow having reversible wings of the present invention are achieved without incurring any substantial relative disadvantage.  
      Although the foregoing description of the snow plow having reversible wings of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made, none of which depart from the spirit or scope of the present invention. The particular embodiments and applications were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such changes, modifications, variations, and alterations should therefore be seen as being within the scope of the present invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.