Patent Publication Number: US-2005120595-A1

Title: Snowplow mounting assembly

Description:
FIELD OF THE INVENTION  
      This invention relates to snow removal equipment and, more particularly, to a snowplow mounting assembly for removably securing a snowplow to a vehicle.  
     BACKGROUND OF THE INVENTION  
      Snow removal has been a problem for as long as motorized vehicles have used public roadways for transportation. In response to the task of removing significant quantities of snow away from roadways, driveways and parking lots, many different types of snowplowing arrangements have been invented. Numerous of these snowplows have been configured to remove snow efficiently from a hill or other uneven surface. In addition, many of these snowplows have been built with hydraulics in order to lift the snowplow into and out of engagement with the road surface.  
      Numerous patents disclose snowplows with one or more pivot axes. U.S. Pat. No. 3,605,906 discloses a snowplow which is capable of rotating about a longitudinally extending axis as well as a transversely extending axis perpendicular to the direction of travel of the vehicle. By fixing the position of the snowplow along these two axes, the snowplow may be moved to a desired position. U.S. Pat. Nos. 3,822,751 and 4,821,436 also disclose snowplows which may be mounted to the front of a vehicle and rotated about at least two axes so as to adjust the snowplow blade to a desired position.  
      Another desirable feature of a snowplow assembly is a jack stand or lift stand capable of supporting the snowplow assembly when not in use. Several patents disclose snowplow assemblies which have lift stands. Applicants&#39; own U.S. Pat. No. 5,125,174, reissued as U.S. Pat. No. Re 35,700, discloses a snowplow assembly having a lift stand which is pivotable about a horizontal axis and may be lifted out of the way when the snowplow assembly is being used to plow snow.  
      Another patent which discloses a pivotable support stand is U.S. Pat. No. 3,150,884. This patent discloses a lift stand which is rotated to an upward position out of the way when a pair of ball joints at the front of a pair of rods secured to the vehicle are received within funnel-shaped guides extending rearwardly from a snowplow assembly.  
      Once a mounting apparatus secured to a vehicle is engaged with a snowplow assembly, it is known to utilize a latch mechanism in order to secure the snowplow assembly to the mount at the front of the vehicle. U.S. Pat. Nos. 5,031,927 and 3,987,562 disclose such latch mechanisms. However, with each of these latch mechanisms a lever must be activated in order to latch the two devices together.  
     SUMMARY OF THE INVENTION  
      The invention of this application provides a number of features and advantages over and above the noted prior art and comprises a snowplow mounting assembly comprising two principal elements: a mount frame adapted to be attached to a vehicle and a snowplow assembly removably attachable to the mount frame.  
      The mount frame of the snowplow mounting assembly comprises a first portion adapted to be attached to a vehicle and a second portion detachable from the first portion. The second portion comprises a pair of spaced receivers, each having a generally rectangular cross-sectional configuration. Each receiver has a top plate, a bottom plate and a pair of laterally spaced side plates. The bottom plate has a depending lip, and at least one of the side plates has a flared portion. A pair of spaced latch pins are located outside of the receivers of the mount frame.  
      The snowplow assembly of the snowplow mounting assembly is releasably securable to the mount frame located on the front of a vehicle. The snowplow assembly comprises a lift frame, a trunnion and an A-frame. The lift frame is generally vertically oriented and includes a pair of headlights. The trunnion is transversely oriented and pivotable about a first transverse horizontal axis relative to the lift frame. The A-frame is pivotable about a horizontal longitudinally extending axis relative to the trunnion. A snowplow blade is attached to the front end of the A-frame.  
      The lift frame includes a lifter or hydraulic cylinder, which is used to lift the snowplow blade vertically upward. A chain or other similar structure extends between the front of the A-frame and lift arms pivotably secured to the lift frame. When the hydraulic cylinder is activated, a piston rod pushes the lift arms upwardly causing the chain to pull the blade upwardly.  
      The lift frame also includes a pair of stand assemblies which are pivotable about a second transversely extending horizontal pivot axis. These stand assemblies are movable between a down position in which the stand assemblies support the snowplow assembly and an up position in which the stand assemblies do not support the snowplow assembly. A latch hook is located on an upper end of each of the stand assemblies. When the stand assemblies are pivoted from their down position toward their up position, the latch hooks move rearwardly and downwardly into engagement with the latch pins of the mount-frame to secure the snowplow assembly to the mount frame at the front of a vehicle. A lock pin assembly on each of the stand assemblies is adapted to lock the stand assemblies in either the up position or the down position.  
      The lift frame further comprises a pair of horns extending rearwardly from the lift frame. The horns of the lift frame are received in the receivers of the mount frame when the snowplow assembly and mount frame are secured together.  
      Each of the stand assemblies is separately and continuously adjustable in length. This adjustable length feature enables the snowplow assembly to be placed on an uneven surface, such as a hill, in such a position that it can easily be mounted on the front of a vehicle. The driver of the vehicle may drive the receivers of the mount frame into engagement with the horns projecting rearwardly from the lift frame of the snowplow assembly. The driver then manually rotates the stand assemblies about the second transversely extending pivot axis until the latch hooks of the stand assemblies engage the latch pins of the mount frame. Thus, with minimal effort in a minimal amount of time, the driver of the vehicle may secure the snowplow assembly to the mount frame secured to the vehicle and proceed to move snow.  
      These and other objectives and advantages of the present invention will be more readily apparent from the following drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION  
       FIG. 1 . is an exploded perspective view of the snowplow mounting assembly of the present invention including a mount frame and a snowplow assembly releasably securable to the mount frame.  
       FIG. 2A  is a side elevational view of the snowplow mounting assembly of the present invention with the mount frame secured to a vehicle before the mount frame is engaged with the snowplow assembly.  
       FIG. 2B  is a side elevational view of the mount frame and snowplow assembly of  FIG. 2A  secured with one another with the snowplow blade in a down position.  
       FIG. 2C  is a view of the mount frame and snowplow assembly secured to one another like  FIG. 2B  but with the snowplow blade being raised to an up position.  
       FIG. 3A  is a top view of the snowplow assembly of the present invention secured to the mount frame with the snowplow blade being perpendicular to the direction of travel of the vehicle.  
       FIG. 3B  is a top view of the snowplow assembly of  FIG. 3A  illustrating the snowplow blade being angled to one side in order to push the snow to one side of the road as the vehicle travels down the road.  
       FIG. 4  is a perspective view of one of the stand assemblies of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION  
      Referring to the drawings, and particularly to  FIG. 1 , there is illustrated a snowplow mounting assembly  10  and comprising a mount frame  12  adapted to be secured to a vehicle  14  and a snowplow assembly  16 .  
      As best illustrated in  FIG. 1 , mount frame  12  comprises a first portion  18  adapted to be attached or secured to the vehicle  14  and a second portion  20  quickly and readily detachable from the first portion  18  without the use of tools, i.e. not requiring wrenches, sockets, removing nuts from bolts, etc. Such a two piece design is advantageous in order that it provides improved, i.e. increased, ground clearance of the mount frame  12  on vehicle  14 , and/or increased “approach angle” of the vehicle  14 , when snowplow assembly  16  is removed from the vehicle  14  during nonuse, as second portion  20  can also be removed leaving only first portion  18  mounted to the vehicle. The term approach angle refers to the angle between the horizontal road surface and a straight line extending from the tangent point of the front tire contacting the road surface to the mount frame, at whatever mount frame location produces the smallest such angle. Stated otherwise, the approach -angle is the angle formed between the road surface and a straight line originating at the tangent point of where the front tire contacts the road surface and swung upwardly to the point where that line first contacts any point on the mount frame. Although one configuration of the first portion  18  of the mount frame  12  is illustrated, this portion may assume numerous other configurations and be attached to a number of different vehicles in numerous ways.  
      The second portion  20  of the mount frame  12  comprises a pair of receivers  22 . Each of the receivers  22  is detachably secured to a respective first portion  18  of the mount frame  12  with a fixed rear pin  24  and a removeable front pin  26 . A slot  30  in receiver  22  engages fixed rear pin  24  which is welded to first portion  18  in rearward most hole  28 . A through passageway  31  in receiver  22  is aligned with forward most hole  28  in first portion  18  and accepts removeable pin  26 . Removeable pin  26  includes a tab  27  fixedly secured thereto with a hole  29  therein that engages over a latch pin  94  secured to receiver  22 , which will be described in more detail below. A “hairpin” (not shown) is manually installed in a hole (not shown) in latch pin  94  (without the use of tools) to secure tab  27  on latch pin  94  and consequently to secure pin  26  in passageway  31 . Thus no tools, wrenches, sockets, etc are required to quickly and readily detach second portion  20  from first portion  18 .  
      Each of the receivers  22  has a generally rectangular cross-sectional configuration and has a bottom plate  34  and a pair of opposed laterally spaced side plates  36 . The bottom plate  34  and side plates  36  define an interior  44  of the receiver  22 . The outermost side plate of each receiver  22  has a flared portion  38 , and the bottom plate  34  has a depending lip  40 . This lip  40  and flared portion  38  aid in guiding horns  42  extending rearwardly from the snowplow assembly  16  into the interior  44  of the receivers  22  in a manner which will be described in more detail below.  
      The snowplow assembly  16  comprises three principal elements best illustrated in FIGS.  3 A and  3 B: a lift frame  46 , a trunnion  48  and an A-frame  50 . For the sake of clarity we will describe each of these elements in detail in the order in which they are located progressing from back to front.  
      The rearward most one of these elements is the lift frame  46  best illustrated in  FIG. 1 . The lift frame  46  is generally vertically oriented and includes lower portion  47  and a pair of supports  56  extending upwardly from the lower portion  47 . A pair of headlights  52  are located at the upper ends of the supports  56 . The lift frame  46  further includes a pair of lift arms  54  extending forwardly from vertical supports  56  at the upper ends of the supports  56 . The lift arms  54  are joined together with a lift bracket  55 . A hydraulically operated lifter  59  comprising piston rod  60  and cylinder  62  extends between the front of the lift arms  54  and a bracket  58  secured to a lower portion of the lift frame  46 . This hydraulically operated lifter  59  functions to lift the A-frame  50  from a lowered position illustrated in  FIG. 2B  to a raised position illustrated in  FIG. 2C . When the piston rod  60  of the lifter  59  is activated, the piston rod  60  raises the lift arms  54  causing a chain  61  to lift the front of the A-frame  50 , the A-frame  50  and trunnion  48  rotating about first transversely extending axis  64  shown in  FIGS. 3A and 3B .  
      As best illustrated in  FIGS. 3A and 3B , the second component of the snowplow assembly  16  is the trunnion  48 . The trunnion  48  comprises a transversely extending bar which is pivotable about the prior-mentioned first transversely extending horizontal axis  64  relative to the lift frame  46 . When the piston rod  60  of the lifter raises the A-frame  50 , both the A-frame  50  and trunnion  48  pivot about the first transversely extending axis  64 . As seen in  FIGS. 3A and 3B , the trunnion  48  is secured to the A-frame  50  with a bolt  66  or other fastener which defines a longitudinally extending axis  68 .  
      The third and last element of the snowplow assembly is the A-frame  50  best illustrated in  FIGS. 3A and 3B . The A-frame  50  comprises a back bar  70  and a pair of side bars  72  arranged in a triangular or “A” configuration. The back bar  70  is secured to the trunnion  48  with the prior-mentioned fastener  66 . A snowplow blade  74  is secured to the front of the A-frame  50 .  
      In order to adjust the snowplow blade  74  such that one is able to push the snow to one side of the road, the snowplow blade  74  is pivotable about a vertical axis  76  illustrated in  FIGS. 3A and 3B . The snowplow blade  74  is movable about this axis by the operation of a pair of hydraulic adjusters  77 . Each adjuster  78  comprises a piston rod  80  extending forwardly from a cylinder  78  in order to push one side of the snowplow blade  74  forwardly relative to the other side of the snowplow blade  74  as illustrated in  FIG. 3B .  
      The rears of the adjusters  78  are secured to the side bars  72  of the A-frame with fasteners  82 . Although hydraulic adjusters are illustrated and described, other mechanisms may be used to rotate the snowplow blade  74  about the vertical axis  76  and fix its position.  
      The A-frame  50  is pivotable about the horizontal longitudinally extending axis  68  relative to the trunnion  48  in order to accommodate further adjustment of the snowplow blade  74  relative to the terrain as will be described below in more detail.  
      The lift frame  46  of the snowplow assembly  16  is supportable by a pair of stand assemblies  84  when the snowplow assembly  16  is separated from the vehicle  14  as illustrated in  FIG. 2A . Each of the stand assemblies  84  is pivotable about a second horizontal transversely extending pivot axis  86  defined by bolt  97  securing stand assembly  84  to lift frame  46 , as illustrated in  FIG. 1 . Each of the stand assemblies  84  is independently pivotable about the axis  86  between a down position in which the stand assemblies  84  support the snowplow assembly  16  as illustrated in  FIG. 2A  and an up position illustrated in  FIG. 2B  in which the stand assemblies  84  do not support the snowplow assembly  16 . As best illustrated in  FIG. 4 , each of the stand assemblies  84  has a latch hook  88  having a concave inner surface  90  and a convex outer surface  92 . As illustrated in  FIG. 2B , the latch hooks  88  are engageable with latch pins  94  (see also  FIG. 1 ) which are a part of the mount frame  12 . The latch pins  94  extend outwardly from the outermost side plates  36  of the receivers  22  of the mount frame  12 . The geometry and configuration of the pins  94 , hooks  88  and bolts  97  (pivot axis  86 ) are such that, when engaged, pin  94  exerts a force on hook  88  which passes through bolt  97 , i.e. pin  94  and hook  88  generate no moment load about bolt  97 .  
      Each of the stand assemblies  84  has a locking assembly  102  which functions to lock the stand assembly in either the up position or the down position. At each side of the lift frame  46  at the lower portion  47  thereof there is a first hole  104  and a second hole  106 , the second hole  106  being located above the first hole  104  ( FIG. 2A ). Holes  104  and  106  are located the same radial distance from axis  86 , i.e. are on the same radius. Each stand assembly further comprises an L-shaped locking pin  108 , illustrated in  FIG. 4  as being within the first hole  104  of the lower portion  47  of the lift frame  46  of the snowplow assembly  16  ( FIG. 2B ). When the locking pin  108  is located inside the first hole  104 , the stand assembly  84  is locked in the down position. In order to move the stand assembly  84  from the down position to the up position, a user must pull outwardly on the locking pin  108  before raising the stand assembly  84  to its up position. To lock the stand assembly  84  in its up position the locking pin  108  is located inside the second hole  106  of the lift frame  46  as illustrated in  FIG. 2   d.  Preferably the locking pin is biased inwardly via a spring (not shown), i.e. is spring biased toward a locking position. Thus, a user need only pull outwardly on locking pin  108  to free the stand assembly  84  relative to the lift frame  46 , move the stand assembly  84  to the desired position i.e. either up or down, while maintaining locking pin  108  retracted, and then simply release the locking pin  108  which by action of the spring bias will automatically insert itself into either hole  104  or  106  as the case may be.  
      As illustrated in  FIGS. 2A and 2B , to secure the snowplow assembly  16  to the mount frame  12  once the horns  42  of the snowplow assembly  16  are located in the receivers  22  of the mount frame  12 , each of the stand assemblies  84  is pivoted upwardly about second transverse horizontal axis  86  (see  FIG. 1 ) causing the latch hooks  88  to engage the latch pins  94  of the mount frame  12 . The inner surfaces  90  of the latch hooks  88  surround the latch pins  94  of the mount frame  12  as illustrated in  FIG. 2B . Advantageously, the latch hooks  88  and the latch pins  94  are so positioned and configured such that a camming action of hooks  88  upon pins  94  occurs thereby drawing the snowplow assembly  16  to the mount frame  12  and hence drawing horns  42  into receivers  22 . And, as mentioned above, the resultant forces generated between hooks  88  and pins  94  pass through the transverse horizontal axis  86  defined by the bolt  97  and in doing so avoid generating a moment about the pivot axis  86 . In doing so the stand  84  is prevented from subjecting locking pin  108  to a shear force during plowing motions which cause plow assembly  16  to tend to be “separated” from the vehicle. Such plowing motions can either be “back dragging,” i.e., dragging plow blade  74  backwardly during “backing up” of the vehicle, or during “windowing,” i.e. plowing with only one lateral side of the blade  74 . By preventing lock pin  108  from being a shear force carrying member during such plowing actions pin  108  can be designed much smaller in diameter than it otherwise could.  
      Describing each stand assembly  84  now in more detail, and as best illustrated in  FIG. 4 , each stand assembly  84  comprises a foot stand  96  and a foot  98  which telescopes into and out of the foot stand  96 . The overall combined height of the foot stand  96  and foot  98  is set by passing a pin  100  through holes  101  in tube  103  of the foot  98  and through holes (not shown) in the foot stand  96 . The position of pins  100  and hence the overall combined height of foot stand  96  and foot  98  are established by the dealer during initial installation of mount frame  12  and snowplow assembly  16  onto a particular vehicle and are dependent upon the particular vehicle on which the plow assembly  16  is to be mounted, the mount frame  12  for that particular vehicle, etc. Thereafter pins  100  are not adjusted.  
      Each of the stand assemblies  84  further comprises a mechanism to continuously or infinitely (within a range) adjust the height of the stand assembly  84  so that each of the stand assemblies has an independently, continuously adjustable height. Such an adjustment feature or mechanism is advantageous when parking snowplow assembly  16  on unlevel ground. Referring still to  FIG. 4 , a handle  110  is fixedly secured to a locking plate  112 , which plate  112  has a hole  113  therein through which foot stand  96  passes. A C-shaped bracket  115  includes upper and lower plates  117  and  119  respectively interconnected by connecting plate  121 . Foot stand  96  passes through holes  123 ,  125  in the plates  117 ,  119  respectively. Slot  127  in connecting plate  121  acts as a fulcrum pivotally supporting the locking plate  112 . The locking plate  112  is normally biased upwardly by compression spring  129  operable between lower plate  119  of C-shaped bracket  115  and locking plate  112 . Thus the edge of hole  113  in locking plate  112  “bites,” or engages, and locks stand  96  in position vertically. A second compression spring  131  is operable between upper plate  117  of C-shaped bracket  115  and a stop  133  secured to an upper end of stand  96 , normally biasing stand  96  to an upward position relative to C-shaped bracket  115 .  
      In operation, and describing first the steps associated with attaching the snowplow assembly  16  to vehicle  14 , snowplow assembly  16  is situated parked with stand assemblies  84  deployed. Vehicle  14  is “driven onto” snowplow assembly  16 , i.e. horns  42  are driven into and received within receivers  22 . Then, each handle  110  for each stand assembly  84  is lifted upwardly slightly, pivoting plate  112  downwardly against the biasing force of compression spring  129  thereby freeing foot stand  96  from the bite of the locking plate  112 . Foot stand  96  is automatically driven upwardly in bracket  115  via compression spring  116 . Pin  100  limits the upward travel of stand  96 . Locking pin  108  is then pulled outwardly out of hole  104  (and retained there against the force of the spring bias). Handle  110  is then rotated upwardly thus rotating the freed stand  84  upwardly. This action causes hooks  88  to “cam” against pins  94  thereby “camming” the snowplow assembly  16  toward the mount frame  12 . Once in the fully up (and latched) position, locking pin  108  is released and automatically inserts into hole  106 . After these steps are performed for each stand assembly  84 , and the vehicle wiring harness (not shown) is connected to the snowplow wiring harness (not shown) the vehicle  14  may be driven off with snowplow assembly  16  attached thereto.  
      Describing now the steps associated with detattaching the snowplow assembly  16  from vehicle  14 , snowplow assembly  16  is situated attached to mount frame  12 , with stand assemblies  84  in their up. (and latching) positions. Locking pin  108  is retracted from hole  106  and is held there against the force of its spring bias while freed stand assembly  84  is pivoted downwardly with handle  110 . Once stand assembly  84  is in the fully down position locking pin  108  is released and automatically inserts into hole  104  thereby locking stand assembly  84  in the down position. The foot stand  96  is then pressed downwardly as by the action of an operator&#39;s hand or foot on disk or stop  133  in the direction of arrow  114 , until the foot  98  contacts the ground surface. After these steps are performed for each stand assembly  84 , and the vehicle wiring harness is disconnected from the snowplow wiring harness, the vehicle  14  may then be backed away from snowplow assembly  16 .  
      To facilitate and ease reattachment of snowplow assembly  16  to vehicle  14 , it is desirable that the horns  42  of lift frame  46 , after snowplow assembly  16  is detached from vehicle  14 , remain positioned so as to still be aligned with receivers  22  of mount frame  12  during reattachment, i.e. during “drive on” of the vehicle  14  and mount frame  12  to the snowplow assembly  16 . The ability of the A-frame  50  and hence blade  74  to pivot about the longitudinal, horizontal axis  68  relative to the rest of the snowplow assembly  16 , and the independently and continuously or infinitely adjustable height feature of the stands  96 , greatly facilitates this later reattachment of the snowplow assembly  16  to the vehicle  14 , when the snowplow assembly  16  has been parked on uneven terrain and detached from the vehicle  14 . During detachment, by incorporating the pivot axis  68  the blade  74  can naturally pivot, independently of the lift frame  46 , as it is lowered onto the ground surface so as to be supported at both ends, i.e. supported at two spaced points along the width of the blade  74 . The lift frame  46  can likewise be supported at both transverse sides by stands  96 , which may require extending one of the stands  96  downwardly (relative to the lift frame  46 ) further than the other stand  96  depending on the terrain. With blade  74  and lift frame  46  so supported, horns  42  will remain generally stationary during withdrawal of receivers  22  from horns  42  as vehicle  14  is backed away from snowplow assembly  16 , and thus will remain generally parallel to and vertically aligned with the receivers  22 . In other words, snowplow assembly  16  will generally undergo no “shifting” upon backing vehicle  14  away therefrom, as the blade  74  and frame  46  have already “reached equilibrium” prior thereto by virtue of the pivot axis  68  and stands  96 . Accordingly, when an operator of the vehicle  14  returns the vehicle  14  to the parked snowplow assembly  16 , the horns  42  will already be aligned with receivers  22  (at least within a margin of error correctable by the flared portions of the receivers  22 ) and vehicle  14  and mount  12  can readily be driven back onto horns  42  and snowplow assembly  16 .  
      An additional advantage of the ability of blade  74  to pivot about the longitudinal, horizontal axis  68  during operation is that it provides a “hugging” action of the blade  74  to the ground surface to provide a cleaner scrape and more even plow blade cutting edge wear.  
      While we have described one preferred embodiment of this invention, persons skilled in the art to which it applies will appreciate changes and modifications which may be made without departing from the spirit of the invention. For example, while the preferred latching mechanism of latching snowplow assembly to mount frame has been described herein as being latch hooks cooperating with latch pins, many other latching mechanisms incorporating cooperating latching elements other than hooks and pins may be used in the practice of the present invention and yet still be within the scope thereof. For another example, while the preferred construction of the snowplow assembly according to the principles of the present invention has been described herein as being comprised of a plow blade, an A-frame, a trunnion and a lift frame, other elements or subassemblies, and both greater in number and fewer in number, than those described and illustrated, may be employed in the practice of the present invention and yet still be within the scope thereof. As yet another example, while the term “A-frame” has been used herein, it is to be understood that other configurations of frames other than “A&#39;s” may be substituted therefore in the practice of the present invention and yet still be within the scope thereof. Therefore, we do not intend to be limited except by the scope of the following claims and their equivalents.