Abstract:
A stabilizer pad apparatus that includes a pair of plate members; and a pad assembly that is adapted for mounting from the pair of plate members. The pad assembly includes a resilient pad having at least one ground engageable work surface and a holder for the resilient pad. A first pivot is provided for supporting the pair of plate members from a stabilizer base; and a second pivot is provided that is substantially transverse to the first pivot for supporting the pad assembly from the plate members.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to stabilizer pads for vehicles, and pertains more particularly to pivotally mounted stabilizer pads. 
   BACKGROUND OF THE INVENTION 
   Most of the major backhoes in production today utilize a stabilizer leg design where the leg (arm) attaches to the frame utilizing a pivot or hinge pin that is basically parallel to the ground, with it&#39;s axis extending in the machine front to rear orientation, when the machine is on its wheels, that is, unsupported by either the stabilizer leg or the front bucket. The stabilizer pad mounting pin to the arm connection, which is parallel to the arm pin, allows the stabilizer pad to pivot so that it is parallel to the ground when supporting or raising the machine. 
   In some machines there may be an unusual stabilizer leg or arm geometry due to the fact that the stabilizer pad is oriented so as to not make contact with the cab structures when the stabilizer leg is in the up position. In these machines the stabilizer arm mounting pin, on the other hand, may be approximately 5 degrees from being parallel in relationship to the ground and this geometry creates an undesirable situation for the stabilizer pad which is mounted on the opposite end of the arm by a pivot pin that is parallel to the arm pivot pin. As a result the pad is very seldom in even parallel contact with the ground when the arm is lowered to support and raise the machine. This, in turn, creates very uneven loading on the resilient surface of the stabilizer pad which results in an uneven wear pattern and premature failure of the resilient pad surface. 
   Accordingly, it is an objective of the present invention to provide an improved stabilizer pad construction that allows the pad to remain parallel to the ground supporting surface when the arm is used to support and raise the machine. The improved pad construction enables this ground parallel support, within certain rotational limits, regardless of the arm pivoting structure and arm orientation. 
   SUMMARY OF THE INVENTION 
   To accomplish the foregoing objective, in accordance with the present invention there is provided a stabilizer pad apparatus that comprises a pair of plate members; and a pad assembly that is adapted for mounting from the pair of plate members. The pad assembly includes a resilient pad having at least one ground engageable work surface and a holder for the resilient pad. A first pivot is provided for supporting the pair of plate members from a stabilizer base; and a second pivot is provided that is substantially transverse to the first pivot for supporting the pad assembly from the plate members. 
   Additional features of the present invention include a pair of side plates between opposite respective sides of the resilient pad and opposite respective sides of the holder. The resilient pad may be a laminated pad including multiple layers, and including a series of pins that hold the layers together, the ends of which engage holes in the side plates. The pad assembly may also include a pair of bolts passing through the holder, side plates and resilient pad. The holder may comprise a walled open pan that receives the resilient pad. The first pivot is defined by a pivot pin that extends between the pair of plate members. The second pivot may include a pair of end plates supported from the plate members. The holder has opposite end rotational flanges that engage with holes in the end plates. The holder preferably has at least one hole for access to the resilient pad for removal thereof. The resilient pad may be formed of multiple layers. 
   In accordance with other embodiments of the present invention there is provided a stabilizer pad apparatus in which the holder comprises a support plate, and means for securing the resilient pad to an underside surface of the support plate. The means for securing may include a pair of unshaped bracket and associated fasteners. The second pivot may include oppositely disposed rods attached to the support plate and pivoted from the plate members. 
   In accordance with another aspect of the present invention there is provided a stabilizer pad apparatus that comprises a metal weldment that is adapted for support from a stabilizer arm of a machine; a resilient pad that is adapted for ground engagement on at least one side thereof; a holder for the resilient pad for supporting the resilient pad from the weldment; and a pivot for supporting the holder from the weldment to permit limited rotation therebetween. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention, reference is made to the drawings which are incorporated herein by reference and in which: 
       FIG. 1  is a perspective view of one embodiment of the stabilizer pad of this invention as attached to a stabilizer arm; 
       FIG. 2  is a front elevation view of the stabilizer pad of  FIG. 1 ; 
       FIG. 3  is a cross-sectional side view of the stabilizer pad of  FIG. 1 , as taken along line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is a cross-sectional front view of the stabilizer pad of  FIG. 1  as taken along line  4 - 4  of  FIG. 3  and showing the arm axis as tilted to the ground; 
       FIG. 5  is a cross-sectional front view of the stabilizer pad of  FIG. 1  as taken along line  5 - 5  of  FIG. 3 ; 
       FIG. 6  is an exploded perspective view of the stabilizer pad of  FIG. 1 ; 
       FIG. 7  is a front elevation view of an alternate embodiment of a stabilizer pad; 
       FIG. 8  is a cross-sectional side view of the alternate stabilizer pad of  FIG. 7  as taken along line  8 - 8  of  FIG. 7 ; and 
       FIG. 9  is an exploded perspective view of the stabilizer pad of the alternate embodiment of  FIG. 7 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” “containing”, “involving”, and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. 
   In the following descriptions the following patents and applications are also incorporated by reference herein in their entirety. These documents describe further details of stabilizer pad structures. U.S. Pat. Nos. 3,897,079; 3,913,942; 4,023,828; 4,761,021; 4,889,362; 5,050,904; 5,054,812; 5,466,004; 5,547,220; 5,667,245; 5,957,496; 5,992,883; 6,109,650; 6,270,119; 6,422,603; 6,471,246; 6,634,672; 6,726,246; U.S. application Ser. Nos. 10/387,898; 10/632,242; 10/773,867. 
   A first embodiment of the present invention is depicted in  FIGS. 1-6 . A second embodiment of the present invention is depicted in  FIGS. 7-9 . In both of the illustrated embodiments the pad arrangement is constructed so that the pad can pivot, about a first axis, from the vehicle stabilizer arm. When the pad arrangement is used on, for example, a backhoe/loader vehicle this first axis extends generally in a direction front-to-back of the vehicle, when in use. To compensate for stabilizer arms that may be slightly tilted forward or back of the center line of the machine, the pad arrangement also has a second pivot, about a second axis, that is preferably transverse to the first axis direction, and that is generally in a direction side-to-side of the vehicle, when in use. In the first embodiment of the present invention, such as in  FIG. 1  the first axis is pivot axis A, while the second axis is the pivot axis B. In the second embodiment of the present invention, such as in  FIG. 7  the first axis is similarly pivot axis A, while the second axis is similarly the pivot axis B. 
   One embodiment of a stabilizer pad  20  in accordance with the present invention will now be described with reference to  FIGS. 1-6 . The second embodiment in  FIGS. 7-9  is described hereinafter. Stabilizer pads that are described in accordance with embodiments of the present invention may be used with a backhoe/loader machine or vehicle, and may also be used with other types of vehicles or machines having stabilizing members for stabilization thereof. The concepts described herein may be applied to either street type pads (primarily for use only on a solid pavement) or reversible pads using grousers. Also, the concepts described herein may be applied to either one-sided pads (resilient pad not meant to be reversed) or two-sided pads (resilient pad meant to be reversed from one side to the other). 
   In the embodiment of  FIGS. 1-6 , the stabilizer pad  20  is shown mounted to a stabilizer arm  22  (base) of a backhoe/loader machine. This particular embodiment is a reversible pad having a resilient side and also a grouser side.  FIGS. 1 and 6  show the grouser points  25 . A cross rod  27 , and its associated hitch pin  29 , illustrated in  FIG. 1 , may be used to limit the rotation of the pad between opposite positions (prevents self-flipping). The pad  20  is mounted by means of the support pin or axle  26  that intercouples the distal end of the stabilizer arm with the stabilizer pad  20 . The pin  26  may be either a one-piece or two-piece pin.  FIG. 4  illustrates the one-piece pin  26 . In this embodiment the resilient laminated pad itself is reversible so as to provide two opposite work surfaces between which the pad can be positioned. 
   The stabilizer pad  20  includes a pair of plate members  24  each having a support collar  28  ( FIGS. 4 and 6 ) for receiving the pin  26 . In  FIG. 1  arrow  31  depicts the direction of rotation of the stabilizer pad  20  relative to the stabilizer arm  22  about axis A.  FIG. 1  also depicts the orthogonal rotation of the pad by arrow  33  about axis B. The pair of plate members  24  are connected together by means of the cross bars  30  and  34 . These cross bars may be welded at each end to the plate members  24  forming a unitary weldment. Each of the plate members  24  is also provided with aligned holes  35  for receiving the cross rod  27 .  FIG. 1  depicts the cross rod  27  in place in one of the sets of aligned holes for assisting in maintaining the pad in the resilient pad side. The other set of aligned holes  35  can receive the cross rod  27  when the pad assembly is rotated, about axis A, to the grouser side of the pad. In that position the cross rod  27  essentially locks the pad assembly in the grouser side position with limited rotation. The stabilizer pad  20  also includes lower cut-outs  36  ( FIGS. 4 and 6 ) for accommodating fasteners, as discussed in more detail hereinafter. 
   The plate members  24  support the pad assembly  40  therebetween, pivoted at opposite ends to enable slight transverse rotation of the pad assembly about axis B. The pad assembly  40  includes the laminated resilient pad  42 , the support pan  44 , side plates  46  and various fasteners that are described later. The support pan  44  is meant for somewhat permanent positioning in the weldment while the laminated resilient pad  42  is replaceable. The support pan  44  has a top wall  47  and four side walls  48  that together form a metal panned structure that is dimensioned to be accommodated between the plate members  24 , and to receive the laminated resilient pad  42 . The top wall  47  is provided with access holes  51  so as to enable one to remove the resilient pad  42  should it get stuck within the support pan. Two holes  51  are illustrated but it is understood that one, or more than two holes may be used. Opposite end walls  48  of the support pan  44  have attached thereto, preferably by welding, circular flanges  52  that are instrumental in pivoting the pad assembly  40  from the weldment about axis B. The circular flanges  52  may be constructed of 2.25 inch outer diameter pipe segments. The support pan  44  is also provided with pairs of holes  55  (see  FIG. 6 ) in the other side walls  48  for accommodating securing bolts  56 . 
   The support pan  44  is pivotally supported between the plate members  24  from the cross bars  30  and  34 . One of the flanges  52  fits within a hole  57  in the cross bar  30 . At the opposite end of the support pan  44 , the other flange  52  is retained in a hole  58  in the retaining piece  60 . The retaining piece  60 , in turn, is fixed by screws  62  to the cross bar  34 . The flanges, being round, enable slight rotation of the pad assembly relative to the weldment (plate members  24  and cross bars  30 ,  34 ).  FIG. 4  shows this rotation by arrow C. The possible angle of rotation may be in a range of 3 to 10 degrees, preferably around 5 degrees. 
   The laminated resilient pad or rubber pack  42  is meant to engage between the lateral side plates or plate members  24 . The pad pack  42  is illustrated in  FIGS. 1-6 , and is formed of a plurality of laminated rubber layers  43  that are stacked together to form the pack. These layers may be compressed and the support rods  66  then engaged. The support for the pack is preferably about midway of the pack so that it can be readily reversed from one working surface to the other. These working surfaces are depicted in  FIG. 4  as ground engaging or working surfaces  67  and  68 .  FIG. 4  shows the work surface  68  in ground engagement. In the embodiments described herein a force fit may used to secure the rods or pins  66  in place. However, there may be a need in certain applications to secure these pins or rods more positively. This may be accomplished by means of a pin structure that is in the form of a reinforcing rod or other roughened surface rod or pin. Also refer to other ways of securing the rods or pins in place such as described in U.S. patent application Ser. Nos. 10/632,242; 10/773,867, which are incorporated by reference herein. 
   A jig or the like may be used to stack the laminate layers  43  with the layers having been drilled with holes of a diameter so that the rods  66  have to be force-fitted into the holes. In this way the rods are held firmly in place and the laminate layers are also firmly stacked against each other. This forms a unitary pad pack  42  that can be easily secured in place with the use of only a couple of securing pins or bolts  56  and associated nuts. In an alternate arrangement, in place of the laminated structure, a solid molded resilient pad can be employed. 
   As indicated hereinbefore, the pad assembly  40  also includes the side plates  46 , one on either side of the resilient laminated pack  42 . Each of these side plates  46  has a series of linearly arranged holes  69  (see  FIG. 6 ), the pattern of which matches the placement of the rods or pins  66  in the resilient pad  42 . The side plates  46  and laminated pack  42  are also provided with holes that line up with the holes  55  in the support pan  44  for accommodating the securing bolts  56 . The exploded perspective view of  FIG. 6  clearly shows the arrangement of the pack  42  and side plates  46 .  FIG. 6  also shows the nuts  72 , washers  73  and spacers  74  associated, respectively, with the securing bolts  56 . 
   Refer also to  FIGS. 3 and 4  for further details of the pad construction. The cross-sectional view of  FIG. 3  is taken through the laminated pad pack  42  showing the securing bolts  56  in place and the rods  66  that tie the laminate structure together.  FIG. 4  is another cross-sectional view illustrating, in particular, the manner in which the pad pack is held in place. In  FIG. 4  it is noted that the spacer or bushing  74  is pressed against one of the side plates  46  against an end layer of the laminate pad  42 . The nut  72  and washer  73  are urged against the bushing  74  and support pan  44 , thus clamping the entire laminated resilient pad structure to the support pan. There is a clearance hole  55  about the bushing  74 . The nut  72  and washer  73  snug up against the side of the support pan  44 . As indicated before,  FIG. 4  also shows the tilt of the pad structure about axis B. The cut-outs  36  in the respective plate members  24  accommodate this slight movement, as is illustrated in  FIG. 4 . 
   The pad pack  42  is also readily reversible once one side thereof is worn down. The pad pack is then dis-assembled by removal of the securing pins or bolts  56  and the pad pack is reversed in position. For example, if the surface  68  is the first working surface and gets worn down, the pad pack can then be reversed 180 degrees so that the surface  69  then is facing downwardly and functions as the ground-engaging surface. Once the bolts  56  are withdrawn the pad pack  42  and side plates  46  can be removed from the support pan  44 . The pad pack  42  can then be reversed in position. The embodiment depicted in  FIGS. 1-6  is also provided with a grouser point side so that, not only is the pad pack reversible, but the weldment itself can be reversed between respective resilient and grouser point sides. 
   Reference is now made to a second embodiment of the present invention that is illustrated herein in  FIGS. 7-9 . This stabilizer pad construction is reversible between resilient and grouser sides, as with the first embodiment. However, the second embodiment uses a non-reversible resilient member, actually two members supported side-by-side, as illustrated in  FIG. 9 . In this second embodiment of the invention the same reference characters are used to identify similar elements found in the first embodiment. 
   In the embodiment of  FIGS. 7-9 , the stabilizer pad  20  is shown mounted to a stabilizer arm  22  of a backhoe/loader machine. This particular embodiment is a reversible pad having a resilient side and also a grouser side.  FIG. 9  shows the grouser points  25 . A cross rod  27  and its associated hitch pin  29  may be used to limit the rotation of the pad between opposite positions (prevents self-flipping), as in the first embodiment. The pad  20  is mounted by means of the support pin or axle  26  that intercouples the distal end of the stabilizer arm with the stabilizer pad  20 . The pin  26  may be either a one-piece or two-piece pin.  FIG. 7  illustrates the one-piece pin  26 . In this embodiment the resilient laminated pad itself is non-reversible, but readily replaceable. 
   In the second embodiment the stabilizer pad  20  includes a pair of plate members  24  each having a support collar  28  ( FIG. 9 ) for receiving the pin  26 . In  FIGS. 7 and 8  the direction of rotation of the stabilizer pad  20  relative to the stabilizer arm  22  is about axis A.  FIGS. 7 and 8  also depict the orthogonal rotation of the pad about axis B. The pair of plate members  24  are connected together by means of the cross bars  30  and  34 . These cross bars may be welded at each end to the plate members  24  forming a unitary weldment. Each of the plate members  24  is also provided with aligned holes  35  for receiving the cross rod  27 .  FIG. 1  depicts the cross rod  27  in place in one of the sets of aligned holes for assisting in maintaining the pad in the resilient pad side. The other set of aligned holes  35  can receive the cross rod when the pad assembly is rotated, about axis A, to the grouser side of the pad. In that position the cross rod essentially locks the pad assembly in the grouser side position. The stabilizer pad  20  also includes lower cut-outs  36  ( FIG. 9 ) for accommodating fasteners, as discussed in more detail hereinafter. 
   The plate members  24  support the pad assembly  140  therebetween, pivoted at opposite ends to enable slight transverse rotation of the pad assembly about axis B. The pad assembly  140  includes the laminated resilient pad  142 , the support plate  144  and various fasteners that are described later. The support plate  144  is meant for somewhat permanent positioning in the weldment while the laminated resilient pad  142  is replaceable. The support plate  144  has a top surface  147  and two end walls  148  that together form a structure that is dimensioned to be accommodated between the plate members  24 , and to receive, or have attached thereto, the laminated resilient pad structure  142 . The top surface  147  is provided with a pair of end rods  151  welded thereto so as to enable pivoting of the pad assembly  140  from the weldment. The tubular rods  151  may be constructed of one half inch diameter metal rods. 
   The support plate  144  is pivotally supported between the plate members  24  from the cross bars  30  and  34 . One of the rods  151  fits within a hole  57  in the cross bar  30 . At the opposite end of the support plate  144 , the other rod  151  is retained in a hole  58  in the retaining piece  60 . The retaining piece  60 , in turn, is fixed by screws  62  to the cross bar  34 . The rods  151 , being round, enable slight rotation of the pad assembly relative to the weldment (plate members  24  and cross bars  30 ,  34 ). This is like  FIG. 4  which shows this rotation by arrow C. The possible angle of rotation may be in a range of 3 to 10 degrees, preferably around 5 degrees. 
   The laminated resilient pad or rubber pack  142  is meant to engage between the lateral side plates or plate members  24 . The pad pack  142  is illustrated in  FIGS. 7-9 , and is formed of a plurality of laminated rubber layers  143  that are stacked together to form the rwo separate packs in the embodiment of  FIGS. 7-9 . These layers may be compressed between U-shaped holders  166  and pins or rods  161  may be used through both the laminated stack and walls of the holder to tie the pad assembly together. The support for each pack is preferably above the midway of the pack so as to provide a sufficient wear surface  163 . 
   In the embodiments described herein a force fit may used to secure the rods or pins  161  in place. However, there may be a need in certain applications to secure these pins or rods more positively. This may be accomplished by means of a pin structure that is in the form of a reinforcing rod or other roughened surface rod or pin. 
   A jig or the like may be used to stack the laminate layers  143  with the layers having been drilled with holes of a diameter so that the rods  161  have to be force-fitted into the holes. In this way the rods are held firmly in place and the laminate layers are also firmly stacked against each other. This forms a unitary pad pack  142  that can be easily secured in place with the use of a few securing studs  156  and associated nuts  157 .  FIG. 9  illustrates the support plate  144  and the two pad assemblies  142 . The plate surface  147  has a series of holes for accommodating the studs  156 .  FIGS. 7 and 8  show the final position of the pad assemblies. In an alternate arrangement, in place of the laminated structure, a solid molded resilient pad can be employed. 
   The second embodiment of the invention provides a relatively simple structure having the characteristic of limited pivoting in a transverse direction to accommodate any slight deviation of the main support pin from the horizontal. The main pivot is shown at axis A while the offsetting pivot is at axis B. Again, refer to  FIG. 4  for an illustration of how the pad surface is essentially self-leveling even when the main pin axis is angularly displaced. 
   Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.