Patent Publication Number: US-7900962-B2

Title: Stabilizer pad for vehicles

Description:
RELATED APPLICATION 
     Priority for this application is hereby claimed under 35 U.S.C. §119(e) to commonly owned and co-pending U.S. Provisional Patent Application No. 60/861,218 which was filed on Nov. 27, 2006. The content of all of the aforementioned application is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates in general to stabilizer pads for vehicles, and more particularly to stabilizer pads that are used with backhoe-type vehicles for supporting stabilizer arms of the vehicle. 
     BACKGROUND OF THE INVENTION 
     Various types of stabilizer pads are described in, for example, U.S. Pat. Nos. 5,992,883 and 6,270,119. These pad structures have a generally flanged first surface for engagement with a soft irregular ground surface such as gravel and have a resilient opposite surface for engagement with a smooth ground surface such as concrete or asphalt. With the increased cost of commodities it is desirable to be able to make a pad product that is sufficiently durable and yet can be made lighter in weight. 
     It is thus an object of the present invention to provide an improved stabilizer pad arrangement that can preferably be constructed lighter in weight and yet is just as durable is past structures. 
     Another object of the present invention is to provide an improved stabilizer pad construction that is more stable in its function whether on the resilient pad side or the grouser side. 
     Still another object of the present invention is to provide an improved stabilizer pad construction that can be manufactured more inexpensively and with fewer production steps. 
     SUMMARY OF THE INVENTION 
     To accomplish the foregoing and other objects, features and advantages of the present invention there is provided a stabilizer pad structure comprising: a weldment formed of a metal plate material that is arranged in a generally U-shaped form including side legs and a connecting base; a resilient pad mounted to said weldment; and means forming pockets in the legs of the weldment for receiving the resilient pad. 
     In accordance with other aspects of the present invention the pockets may be formed by bending the plate material on either side of each leg; the resilient pad may be a laminated pad; a clamp bar and securing bolts may be provided for securing the resilient pad in the pocket; the weldment may also include a pair of grouser flanges on the opposed side of the pocket and with each grouser flange overlying the footprint of the resilient pad; each grouser flange may be disposed within the center 80% of the resilient pad; a clamp bar may be disposed between the resilient pad and one of the side legs and at least one securing bolt; the clamp bar may have a threaded hole for receiving a threaded section of the bolt; the bolt may have an end post received in a hole in the leg; an L-shaped bracket may be provided having one arm for contacting one of said legs and another arm for contacting the resilient pad, and at least one securing bolt. 
     In accordance with another feature of the present invention there is provided a stabilizer pad structure comprising: a weldment formed of a metal plate material that is arranged in a generally U-shaped form including side legs and a connecting base; and a resilient pad mounted to the weldment; wherein the weldment also includes a pair of grouser flanges on the opposed side of the pocket and with each grouser flange overlying the footprint of the resilient pad. 
     In accordance with other aspects of the present invention each grouser flange may be disposed within the center 80% of the resilient pad; means are provided forming pockets in the legs of the weldment for receiving the resilient pad; a clamp bar and securing bolts are provided for securing the resilient pad in the pocket. 
     In accordance with another feature of the present invention there is provided a method of constructing a stabilizer pad structure comprising the steps of: forming a blank that includes a pair of side legs connected by a base member with the blank being of generally U-shaped configuration; providing a pair of side wings on each leg; bending the side wings of both side legs to form respective side leg pockets; and attaching a pair of grouser flanges extending along respective side legs. 
     In accordance with other aspects of the present invention including securing a resilient pad in each of the formed pockets; wherein said side wings are bent in a first direction and the grouser flanges are attached so as to extend in a second direction that is substantially orthogonal to the first direction; including securing the resilient pad by means of one or more securing bolts; including providing a clamp bar between the resilient pad and bent leg or including providing an L-shaped clamp bracket between the resilient pad and bent leg. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       It should be understood that the drawings are provided for the purpose of illustration only and are not intended to define the limits of the disclosure. The foregoing and other objects and advantages of the embodiments described herein will become apparent with reference to the following detailed description when taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of a preferred embodiment of the improved stabilizer pad of the present invention; 
         FIG. 2  is a right side elevation view of the stabilizer pad of  FIG. 1 ; 
         FIG. 3  is a front elevation view of the stabilizer pad of  FIG. 1 ; 
         FIG. 4  is a fragmentary cross-sectional view as taken along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is a perspective view of the pad blank that is used in constricting the pad of  FIG. 1 ; 
         FIG. 6  is an exploded perspective view of the stabilizer pad of  FIG. 1 ; 
         FIG. 7  is a fragmentary cross-sectional view like that shown in  FIG. 4  but with an alternate clamping arrangement; and 
         FIG. 8  is a plan view of the blank of  FIG. 5  in relation to the grouser flanges. 
     
    
    
     DETAILED DESCRIPTION 
     Reference is now made to the drawings for an illustration of the stabilizer pad of the present invention. The pad is comprised of a metal weldment that has a grouser on one side and mounts a pair of resilient pads on the other side. The basic weldment is of generally U-shape. The stabilizer pad is meant for support from a stabilizer arm  6  of earth moving equipment such as a backhoe. The weldment of the stabilizer pad is supported from the stabilizer arm  6  by means of a pin  10 .  FIG. 1  shows the pin  10 . For a similar support stabilizer arm refer, for example, to my earlier U.S. Pat. No. 6,270,119 which is hereby incorporated by reference in its entirety. 
     The stabilizer pad is constructed using a main plate member  12  that is generally of U-shape. The plate member  12  includes opposed legs  14  and contiguous base  16 . Each of the legs  14  has attached thereto grouser flanges  20 . Each of the grouser flanges is attached to the main plate by means of weld joints  22  only some of which are shown in  FIG. 1 . The grouser flanges  20  are disposed substantially orthogonal to the plane of the weldment plate.  FIG. 1-3  also illustrate the counterweights  24  which may be attached to the respective grouser flanges  20  and/or the legs  14 . Due to the arrangement of the grouser flanges relative to the plate member, the counterweights  24  are of relatively light weight, as is discussed in further detail hereinafter. 
       FIG. 1  also illustrates the pivot pin  10  which is attached to the flanges  20  at bushings  26 . Each of the bushings  26  may be welded to their corresponding grouser flange  20 . In accordance with the present invention the pin  10 , rather than being free rotating in the bushings  26  is secured by a bolt  27  or the like. The bolt  27  may extend through holes  29  provided in the bushing  26  and the pin  10  and each bolt  27  is secured by means of an associated nut  28 . The pin  10  also passes through the hole  8  inn the stabilizer arm  6 . This securing between the pin  10  and the stabilizer pad weldment provides the proper force transfer. The pin  10  functions, not only to provide the rotation, but also force transfer, absorbing some of the force directly at the pin and thus not relying exclusively upon the weldment itself for load transfer. 
     Each of the grouser flanges  20  is provided with spaced grouser points  25 . In this regard refer to the side view of  FIG. 2  that shows the grouser points  25  one disposed on each side of the pin  10 . More than two grouser points may also be provided associated with each of the grouser flanges  20 . 
       FIGS. 5 and 8  are an illustration of the configuration of the plate member  12  at an initial step. This may be cut from a piece of plate steel by a well known process such as by means of a plasma cutting technique. The plate member  12  is preferably symmetric about the center line  13 . After the plate member is cut into, the shape shown in  FIG. 5 , then a bending operation is provided so as to bend side portions  30  associated with each of the legs  14 . These side portions are bent at a 90 degree angle and form the respective side walls  30  depicted in  FIGS. 1 and 3 .  FIGS. 4 and 6  show how the sidewalls  30  form a pocket  32  for receiving the resilient pad  34 . There is a resilient pad  34  associated with each of the pockets  32 . Each pocket  32  has opposed sidewalls  30 . 
     The resilient pad  34  may be a molded rubber pad but is preferably a laminated pad that is comprised of a series of laminated layers  36 . These laminated layers  36  are preferably held together by a series of pins  38  that pass through holes  39 .  FIGS. 2 and 6  illustrate the configuration of each pad layer. Each of these pad layers preferably has a wave-like ground contact surface  37 . As illustrated in  FIG. 6 , the laminated layers may be tied together by means of three force fit pins  38  that are forced into passages in each of the laminated layers by a pressing operation. 
     As illustrated in  FIG. 6 , each of the sidewalls  30  is also provided with holes  31  that are positioned in alignment with holes  41  in the laminated pad. Refer also to  FIG. 4  for an illustration of the position of the holes  31  and  41 . These holes in the pocket and in the resilient pad are for accommodating the securing bolts  40 . The configuration of the securing bolts  40  is illustrated in  FIGS. 4 and 6 .  FIG. 4  is a partial cross-sectional view illustrating the manner in which the bolt  40  passes through the sidewalls  30  and also through the resilient pad  34 . The securing bolt  40  includes a head  42  that may be a hex head and a shaft  44  that is threaded near its distal end as illustrated at  46 . The very distal end of the bolt  40  is provided with an end post  48  that is of slightly smaller diameter than the diameter of the main shaft of the bolt. 
     As illustrated in  FIG. 4  the bolt  40  passes through one of the sidewalls  30 , through the resilient pad  34  and is threaded at  46 . The clamp bar  50  has internally threaded holes  51  for receiving the threaded part of each bolt. The end post  48  is adapted to fit within a hole in the opposite sidewall  30 . The end post  48  is preferably not threaded and is provided with a slight loose fit in the unthreaded hole in the sidewall  30 . The threading of the bolt  40  with the clamp plate  50  clamps the entire resilient pad within its pocket. This is clearly shown in  FIG. 4  where the tightening of the bolts  40  causes the clamp bar  50  to be urged against the laminated layers  36 . 
     One of the stable aspects of the present construction is the relationship between the grouser flange  20  as it relates to the location of the resilient pad  34 . In this regard refer to  FIG. 8  which shows the grouser flanges  20  and, in dotted outline, the position of the resilient pad  14 . It is noted that the grouser flange  20  is disposed over the resilient pad (in  FIGS. 1 and 2 ). In other words the flange is constructed and arranged over the footprint  15  of the resilient pad as represented in  FIG. 8  by the dotted outline of the pad  14 . The grouser flange  20  is disposed, in the longitudinal direction of the resilient pad, near the center of the resilient pad but offset just slightly. In  FIG. 8  the grouser flange  20  is approximately at a position one-third of the width of the resilient pad. 
     By placing the flange  20  within the footprint  15  the loading of the pad is more effectively transferred to the pin  10 . The pin  10  could also be lengthened to bring the flanges  20  closer to or at the center of the footprint, however, the longer the pin, it tends to cantilever out from the arm more and possibly become overloaded. The flange position relative to the resilient pad footprint is preferably within the center 80% of the footprint as illustrated in  FIG. 8 . Refer also to  FIG. 3  for an illustration of the relationship between the flanges  20  and the pad footprint  15 . This transfers the load more directly to the mounting pin  10 . As can also be seen from  FIGS. 1 ,  6  and  8 , each grouser flange  20  extends substantially the full length of each leg  14  and further includes a slightly turned end  20 A, terminating at the cross base  16 . These ends  20 A provide some additional strengthening of the pad structure. 
     Another feature relating to the stability of the pad construction of the present invention is illustrated in  FIG. 2  wherein it is noted that, regarding the elongated dimension of the resilient pad, the resilient pad  34  is disposed so that the pin  10  is approximately at the center thereof. Refer to the center line  11  in  FIG. 2 . This provided for a stable centering and proper force transfer from the stabilizer arm to the pad. The pin is located preferably within the center 40% of the longitudinal length of the resilient pad  34 . 
     Another feature of the design of the present invention is that the complete stabilizer pad construction can be made lighter, and yet without compromising the strength and effectiveness of the design. This lighter, simplified construction requires less material and far fewer manufacturing operations than previous designs. Particularly, there is far less need of separate welding operations. For example, the thickness of the main plate material need only be about ⅜ inch thick. Part of the reason as to why the pad can be made lighter relates to the way in which the pin  10  is bolted with the weldment so as to absorb load transfer. In this way some of the twisting/pivoting forces on legs  14  are transfered onto/through the pin  10  making for a very robust construction. When the earthmoving equipment is working on uneven surfaces these legs  14  tend to have a scissoring motion about pin  10  independently of each other. This motion transfers through the base  16  onto the pin  10  which resists this rotation through its connections at each end through bolt  27 , bushing  26 , grouser flanges  20 , legs  14  and base  16 , thus essentially unifying both legs  14 . 
     Another attribute allowing the utilization of lighter construction materials is the more symmetrical location of the grouser points  25  over the resilient pad  34 , and relative to the pin  10 . Refer to the side view of  FIG. 2  showing that relationship with the pin  10  disposed between the grouser points  25 . This lessens the rotational forces placed upon the supporting weldment about an axis that is parallel to the long axis of the laminated rubber pocket  32 . 
     Reference is now made to an alternate arrangement shown in  FIG. 7  for securing the resilient pad in place in its accommodating pocket. This uses a separate angle bracket  50 A that has arms  52  and  54 . The bracket  50 A is mounted on the outside of the pocket thus making for a somewhat more compact arrangement. Arm  52  is shown against the sidewall  30  while the free end of arm  54  is urged against the laminate layers  36  to compress and hold the pad in place. The bracket may be used without any clamp bar or may be used with a clamp bar.  FIG. 7  also shows the bolt  56  with its head at the bracket end, but the bolt may also pass in the opposite direction. In  FIG. 7  the outer sidewall  30  may have a smooth hole or an internally threaded hole  31  for receiving the end of the bolt  56 . The bracket  50 A may be disposed on either side of the pocket. Alternatively, the hole  31  may be non-threaded and a nut  58  and lock washer  57  may be used to clamp the laminated layers in place, as shown in  FIG. 7 . 
     Having now described some embodiments of the present invention it should be apparent to those skilled in the art that other embodiments and modifications thereof are contemplated as falling within the scope of the present invention. For example, a two-sided pad has been described herein including both grouser and resilient pad sides. However, certain aspects of the present invention can also be practiced with a one-sided pad in which only the resilient pad is used and the pad is not reversible between sides.