Patent Publication Number: US-2013248211-A1

Title: Method and apparatus for maintaining level plow when angling

Description:
This application claims priority to U.S. Ser. No. 61/614,594, entitled METHOD AND APPARATUS FOR MAINTAINING LEVEL PLOW WHEN ANGLING, filed Mar. 23, 2012, which is incorporated herein by reference. 
    
    
     I. BACKGROUND OF THE INVENTION 
     This invention pertains to the art of methods and apparatuses for plow assemblies and more specifically to methods and apparatuses for supporting a plow blade to a vehicle so that it is maintained in a level orientation even when the plow blade is both raised and moved side-to-side. 
     II. SUMMARY OF THE INVENTION 
     According to one embodiment of this invention, a plow assembly may comprise a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and, a support assembly that supports the plow blade assembly to an associated vehicle. The support assembly may comprise: (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly; (2) a blade height adjustment mechanism that is operable to raise and lower the blade support structure and the plow blade assembly with respect to an associated ground surface; and, (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a substantially vertical first pivot axis about which the blade support structure and the plow blade assembly are pivotal together with respect to the first frame component; and a second end; (b) a second frame component comprising: a first end defining a second substantially horizontal pivot axis about which the second frame component is pivotal with respect to the vehicle when the blade height adjustment mechanism operates to raise and lower the blade support structure and the plow blade assembly; and a second end; (c) at least a first power device that is operable to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a substantially horizontal third pivot axis so that the first frame component, the blade support structure and the plow blade assembly are automatically pivotal together about the third pivot axis to maintain the plow blade in a level orientation when: (i) the blade height adjustment mechanism is operated to raise the blade support structure and the plow blade assembly with respect to the associated ground surface; and, (ii) the first power device is operated to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis. 
     According to another embodiment of this invention, a plow assembly may comprise a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and, a support assembly that supports the plow blade assembly to an associated vehicle. The support assembly may comprise: (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly; (2) a blade height adjustment mechanism that is operable to raise and lower the blade support structure and the plow blade assembly with respect to an associated ground surface; and, (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a first pivot axis about which the blade support structure and the plow blade assembly are pivotal together with respect to the first frame component; and a second end; (b) a second frame component comprising: a first end defining a second pivot axis about which the second frame component is pivotal with respect to the vehicle when the blade height adjustment mechanism operates to raise and lower the blade support structure and the plow blade assembly; and a second end; (c) at least a first power device that is operable to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a third pivot axis so that the first frame component, the blade support structure and the plow blade assembly are pivotal together about the third pivot axis. 
     According to one embodiment of this invention, a method of maintaining a plow blade in a level orientation may comprise the steps of: (A) providing a plow assembly comprising: (I) a plow blade assembly comprising: a plow blade having a plow surface that is suitable to contact and plow an associated plowable substance; and, (II) a support assembly that supports the plow blade assembly to an associated vehicle, the support assembly comprising: (1) a blade support structure that is attached to the plow blade assembly and that supports the plow blade assembly to the support assembly; (2) a blade height adjustment mechanism; (3) a blade side-to-side adjustment mechanism comprising: (a) a first frame component comprising: a first end attached to the blade support structure and defining a first pivot axis; and a second end; (b) a second frame component comprising: a first end defining a second pivot axis; and a second end; (c) at least a first power device; and, (d) wherein the second end of the first frame component is pivotally attached to the second end of the second frame component about a third pivot axis; (B) operating the blade height adjustment mechanism to pivot the second frame component about the second pivot axis and to raise the blade support structure and the plow blade assembly with respect to an associated ground surface; (C) operating the first power device to cause the blade support structure and the plow blade assembly to pivot together about the first pivot axis with respect to the first frame component; and, (D) maintaining the plow blade in a level orientation by automatically pivoting the first frame component, the blade support structure and the plow blade assembly together about the third pivot axis with respect to the second frame component. 
    
    
     
       III. BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may take physical form in certain parts and arrangement of parts, embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein: 
         FIG. 1  is a perspective front view of a vehicle equipped with a plow assembly. 
         FIG. 2  is a side perspective close-up view of the vehicle and plow assembly shown in  FIG. 1 . 
         FIG. 3  is a top perspective close-up view of the plow assembly shown in  FIG. 1 . 
         FIG. 4  is a perspective side close-up view of the plow assembly shown in  FIG. 1 . 
         FIG. 5  is a side perspective schematic view of the lift mechanism shown in  FIG. 1  with the chain represented as a pair of rods. 
         FIG. 6  is a top perspective view of a support frame. 
         FIG. 7  is a bottom perspective view of the first frame component. 
         FIG. 8  is a top perspective view of the first frame component. 
         FIG. 9  is a view taken along the line  9 - 9  of  FIG. 8 . 
         FIG. 10  is a view taken along the line  10 - 10  of  FIG. 8 . 
         FIG. 11  is a top perspective view of the second frame component. 
         FIG. 12  is a view taken along the line  12 - 12  of FIGURE 
         FIG. 13  is an end view of the second frame component of  FIG. 11 . 
         FIG. 14  is a perspective view of a clevis. 
         FIG. 15  is a top view of the clevis of  FIG. 16 . 
         FIG. 16  is a side view of the clevis of  FIG. 16 . 
         FIG. 17  is a perspective end view of a support frame according to another embodiment. 
         FIG. 18  is a side perspective view of the support frame shown in  FIG. 17 . 
         FIG. 19  is an end view of the support frame shown in  FIG. 17 . 
         FIG. 20  is a view similar to that shown in  FIG. 17  but it shows the first frame component rotated relative to the second frame component. 
         FIG. 21  shows a support frame according to yet another embodiment. 
     
    
    
     IV. DETAILED DESCRIPTION 
     Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the invention only and not for purposes of limiting the same, and wherein like reference numerals are understood to refer to like components,  FIG. 1  shows a vehicle  10  equipped with a plow assembly  30  according to one embodiment of this invention. While the vehicle shown is commonly known as a pick-up truck, it should be understood that the plow assembly  30  of this invention will work well with any vehicle chosen with the sound judgment of a person of skill in the art. The plow assembly  30  may include a plow blade assembly  32  and a support assembly  34  that supports the plow blade assembly  32  to the vehicle  10 . The plow blade assembly  32  has a plow blade  36  with a plow surface  38  that is suitable to be used to contact and plow snow, ice or the like as is well known to those of skill in the art. However, it should be understood that the plow assembly of this invention can be used with plow blades that are suitable to be used to contact and plow any plowable substance, such soil, chosen with the sound judgment of a person of skill in the art. While the plow blade  36  shown is of a specific type and shape, it should be understood that any plow blade chosen with the sound judgment of a person of skill in the art will work well with this invention. 
     With reference now to  FIGS. 1 ,  2  and  5 , the support assembly  34  may include a blade support structure  40 , a blade height adjustment mechanism  42 , and a blade side-to-side adjustment mechanism  44 . The blade support structure  40  may have a distal (away from the vehicle) side to which the plow blade assembly  32  attaches. One or more tabs  46  may extend from the distal side and receive pins  48  that hold the plow blade assembly  32  to the support assembly  34 . For the embodiment shown, the pins  48  also define a pivot axis A 5  about which the plow blade assembly  32  can pivot or “trip” as is well known to those of skill in the art. 
     With reference now to  FIGS. 1-5 , the blade height adjustment mechanism  42  may include a lift frame  50  having a proximal (near the vehicle) end with one or more attachment brackets  52  which attach to the vehicle in a known manner. A lift arm  54  may have a proximal end pivotally attached, about generally horizontal and perpendicular to the length of the plow assembly  30  pivot axis Al, to the distal end of the lift frame  50 . The lift arm  54  may extend distally from the distal end of the lift frame  50 , as shown. A middle portion of a chain  56  may attach to the distal end of the lift arm  54  (such as via openings  58 ) and the opposite ends of the chain  56  may extend downwardly and attach to the blade support structure  40 , as shown. Alternatively, two separate chains could be used. A power device or ram  60 . such as hydraulic cylinder, may be connected between the lift frame  50  and the lift arm  54 . as shown. In other embodiments, the power device may comprise a pneumatic cylinder or an electric motor. When the power device  60  is extended, the lift arm  54  pivots in direction D 1  and exerts a lift force (tension) onto the chain  56  which cause the blade support structure  40  (and the plow blade assembly  32 ) to be lifted. When the power device  60  is contracted, the lift arm  54  pivots in the opposite direction which permits the blade support structure  40  (and the plow blade assembly  32 ) to be lowered. As the operation of a power device with a plow blade is well known to those of skill in the art, further details will not be provided here. 
     With reference now to  FIGS. 2 ,  5  and  6 , the blade side-to-side adjustment mechanism  44  may include a support frame  64  having a proximal end that pivots with respect to the vehicle  10 . For the embodiment shown, the support frame  64  includes one or more attachment brackets  66  which pivotally attach, about a generally horizontal and perpendicular to the length of the plow assembly  30  pivot axis A 2 , to the lift frame  50 , as shown. Alternatively, the proximal end of the support frame  64  could be pivotally attached to the vehicle. The distal end of the support frame  64  may have one or more attachment brackets  70  with pivotally attach, about a generally vertical axis A 3 , to the blade support structure  40 . This permits the blade support structure  40  (and thus the plow blade assembly  32 ) to be pivoted about axis A 3  from side to side. The blade support structure  40  may have one or more (two shown) contact surface  68  that contact the support frame  64  to limit the degree of pivoting about axis A 3 . 
     With reference now to FIGS.  2  and  5 - 10 , the support frame  64  may be an A-frame (a frame shaped like the letter A), as shown. Unlike known support frames, however, support frame  64  is made of two primary frame components that are moveable relative to each other. Specifically, the support frame  64  shown has a first frame component  72  positioned relatively distally and a second frame component  74  positioned relatively proximally. The first frame component  72  includes the attachment brackets  70 ,  70  (two shown) which may have bushings  76  with openings  78  that receive a pivot pin  80  that is received in at least one opening in the blade support structure  40  and that defines the generally vertical pivot axis A 3 . The attachment brackets  70 ,  70  may “sandwich” the top and bottom surfaces of the blade support structure  40 . The first frame component  72  may include a pair of tubes  82 ,  82  that form a V-shape with the distal ends attached to the attachment brackets  70 ,  70 , as shown. A plate  84  may be attached to the proximal end of the first frame component  72 . The plate  84  may have a pair of tabs  86 ,  86  extending from opposite sides of the first frame component  72 , as shown. To provide further support and stability, atop and bottom plate  88 ,  90  may attached to the first frame component  72 . 
     With reference now to  FIGS. 2 ,  5 - 6  and  10 - 13 , the second frame component  74  includes the attachment brackets  66 ,  66  which may extend proximally from an angle member  94  and which may have openings  92 ,  92  that receive pivot pins defining the pivot axis A 2 . A pair of tubes  96 ,  96  may form a V-shape and have proximal ends attached to the angle member  94 . The distal ends of the tubes  96 ,  96  may be attached to a plate  98 . Onto each side of the plate  98  at least one contact surface  101  may be provided. For the embodiment shown, each side of the plate  98  has a bracket  100  fixed thereto with an opening  102 . Surfaces of the bracket  100  defining the opening  102  define two contact surfaces  101 ,  101  on the top and bottom of the opening  102 , as indicated in  FIG. 12 . The plate  98  and brackets  100 ,  100  may be sized such that the plate  84  is positioned juxtaposed to the plate  98  and the tabs  86 ,  86  are received within the openings  102 ,  102 . The height of each opening  102  may be greater than the height of each tab  86  so that relative motion is possible. In one embodiment, shown in  FIGS. 11-12 , the brackets  100  have an even thickness around the openings  102 . In another embodiment, seen best in  FIG. 18 , one side  101 A of the bracket  101  has a curved outer surface to provide additional strength. 
     With continuing reference to  FIGS. 2 ,  5 - 6  and  10 - 13 , the plate  98  may have a hole  104  and the plate  84  may have a hole  106 . The holes  104 ,  106  may be positioned concentrically and receive a pivot pin  108  (most visible in  FIG. 18 ) that defines a generally horizontal and parallel to the length of the plow assembly  30  pivot axis A 4 . In this way, the first frame component  72  is relatively pivotal with respect to the second frame component  74  about pivot axis A 4 . The top and bottom surfaces of the tabs  86  contact the contact surfaces to limit the relative pivotal motion in both rotational directions. The design shown is capable of providing about  12  degrees of relative pivoting of the first frame component  72  with respect to the second frame component  74 . Other relative degrees of relative pivoting are easily attainable, as known by those of skill in the art. In an alternate embodiment, one or more contact surfaces  101  are provided on the first frame component  72  and one or more tabs are provided on the second frame component  74 . 
     With reference now to  FIGS. 2 ,  4 - 6 , and  14 - 16  at least one power device or ram  110  (two shown), such as a hydraulic cylinder, may be connected between the second frame component  74  and the blade support structure  40 . In other embodiments, the power device may comprise a pneumatic cylinder, an electric motor, or a biasing member such as a spring. For the embodiment shown, the proximal ends of the power devices  110 ,  110  are attached to a pair of attachment brackets  112 ,  112  on opposite sides of the second frame component  74  and the distal ends of the power devices  110 ,  110  are attached to a pair of attachment brackets  114  on the blade support structure  40 . A clevis  116  may be used for each of these four attachments thus providing each end of each cylinder  110  with the capability of pivoting relatively both about a generally horizontal and perpendicular to the length of the plow assembly  30  pivot axis and about a generally vertical pivot axis. 
     With reference now to all the FIGURES, one advantage of this invention is realized when mounting and dismounting. It is well known for the ground surface upon which the plow assembly  30  is stored to be uneven. As a result, the elevation of the wheels on the vehicle (to which the plow assembly  30  is to be mounted) may be different that the elevation of the plow assembly  30 . The relative motion permitted between the first frame component  72  and the second frame component  74 , which occurs automatically, minimizes this problem. 
     Another advantage of this invention is realized when the plow blade assembly  32  is raised/lifted. The relative motion permitted between the first frame component  72  and the second frame component  74  allow the plow blade assembly  32  to remain substantially flat or level (at the same elevation) when it is raised/lifted (off the ground) and pivoted from side to side. Prior to this invention, lifting and side-to-side pivoting of known plow blade assemblies causes one end of the plow blade assembly to dip or drop in elevation. This creates a greater likelihood of inadvertently striking an object (including the ground) with the dipping edge of the plow blade. Suppose, for example, that the plow blade assembly  32  is in the position shown in  FIG. 1 , raised and angled generally straightforward. Suppose further that the operator then activates the controls to cause the plow blade assembly  32  to pivot to one side. Before this invention, such action by the operator would cause one end of the plow blade assembly  32  to dip. With this invention, however, such dipping does not occur. Instead, when the forces exerted on the blade support structure  40  by the chain  56  become uneven (this occurs when the side-to-side motion occurs) the first frame component  72  automatically pivots with respect to the second frame component  74  and the dipping is eliminated (or greatly minimized). Because of the use of the clevises  116 , this relative motion of the first frame component  72  with respect to the second frame component  74  does no damage to the cylinders  110  as they easily accommodate to the corresponding differing elevations at the distal ends of the cylinders  110 . 
     Yet another advantage of this invention is realized when the plow is used on an uneven surface. If the ground surface is angled to one side or undulates during plowing, the relative motion permitted between the first frame component  72  and the second frame component  74  allows the plow blade assembly  32  to automatically follow the ground surface contour. 
       FIGS. 17-20  show another embodiment. For this embodiment, the support frame  64  includes first and second frame components  72 ,  74  each having plates  84 ,  98 , respectively, that are pivotal about pivot pin  108 , as with previously described embodiments. However, this embodiment also includes an additional component(s) to maintain the plates  84 ,  98  in the proper relative position. Specifically, at least one bracket  130 , two shown, “sandwich” the plates  84 ,  98  to maintain the proper relative position. The brackets  130 ,  130  may be positioned substantially equidistant from the longitudinal axis of the frame  64 , as shown. In one embodiment, shown. the brackets  130  are fixed to the plate  98  but are movable with respect to the plate  84 . This can be seen by comparing  FIG. 17  to  FIG. 20 . In another embodiment, the brackets  130  are fixed to the plate  84  but are movable with respect to the plate  98 . Each plate  84 ,  98  may have a tab  132 ,  134  respectively, extending from their upper surface, as shown. These tabs  132 ,  134  would contact the brackets  130 ,  130  if the side-to-side relative position of the plates  84 ,  98  was too great. In this way, the brackets  130 ,  130  and tabs  132 ,  134  together work as a “stop” to prevent undesirable relative motion. 
       FIG. 21  shows another embodiment where once again the support frame  64  includes first and second frame components  72 ,  74  each having plates  84 ,  98 , respectively, that are pivotal about pivot pin  108 . This embodiment uses a bracket  136  with an opening  138  that receives the tabs  132 ,  134  (similar to those shown in  FIGS. 17-20 ) to prevent undesirable relative motion between the plates  84 ,  98  in a manner similar to the brackets  130 ,  130  discussed above. 
     Numerous embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof. 
     Having thus described the invention, it is now claimed: