US3831774A

US3831774A - Vehicle outrigger pad structure

Info

Publication number: US3831774A
Application number: US00404092A
Authority: US
Inventors: H Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-05
Filing date: 1973-10-05
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27

Abstract

A pad structure of generally circular configuration for attachment to the stabilizing outriggers of a vehicle such as a backhoe. The structure includes a base and peripheral side wall covered with rubber. Each pad structure is mounted to its associated outrigger by a ball joint which allows the pad to rotate and also to conform to the grade of the supporting surface. The pad is resistant to wear because of the rubber material, because of its configuration, and because of its capacity for rotation. Instead of dragging and digging into the supporting surface and adjacent structures, such as curbs and the like, it moves and thereby continually presents new wearing surfaces. Other features include means enabling ready removal and replacement of worn pads.

Description

United States Patent [191 Moore Aug. 27, 1974 VEHICLE OUTRIGGER PAD STRUCTURE Harold K. Moore, 4833 Dunrobin Ave., Lakewood, Calif. 90713 Filed: Oct. 5, 1973 Appl. No.: 404,092

Inventor:

US. Cl. 212/145, 248/24 Int. Cl. B66c 23/62 Field of Search 212/145; 254/86 R; 188/7;

References Cited UNITED STATES PATENTS 3/l962 Kramcsak, Jr. et a]. 254/86 R 10/1966 Noller 212/145 ABSTRACT A pad structure of generally circular configuration for attachment to the stabilizing Outriggers of a vehicle such as a backhoe. The structure includes a base and peripheral side wall covered with rubber. Each pad structure is mounted to its associated outrigger by a ball joint which allows the pad to rotate and also to conform to the grade of the supporting surface. The pad is resistant to wear because of the rubber material, because of its configuration, and because of its capacity for rotation. Instead of dragging and digging into the supporting surface and adjacent structures, such as curbs and the like, it moves and thereby continually presents new wearing surfaces. Other features include means enabling ready removal and replacement of worn pads.

5 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION ground or roadway as the backhoe progressively advances along a predetermined digging path. Often the digging is closely adjacent a street curb or the like and the commonly used rectangular steel plates which are used for the outrigger pads strike against the curb and break it up so that it has to be replaced. The dragging sharp cornered plates also often tear up street surfaces so that they too have to be replaced.

SUMMARY OF THE INVENTION According to the present invention, an outrigger pad structure is provided for attachment to the end of each of the usual outriggers that are used to support and stabilize a vehicle such as a backhoe. The pad structure comprises a foot having a base and a generally circular peripheral side wall over which is fitted a resilient pad. The pad is anchored in position on the wall by surface protrusions such as ribs or the like provided on the wall. The foot is connected to its outrigger by a ball joint assembly operative to permit the foot to pivotally conform to the grade of the road or other supporting surface, and further operative to permit the foot to rotate about a generally vertical axis. With this arrangement the resilient pad does not tear up or destroy the roadway or adjacent street curbs or the like. Instead, the pivotal conformation of the pad to the roadway tends to wear the pad more evenly; there are no sharp corners to dig into the roadway; and, as the pad is dragged over the roadway, or strikes a curb, it tends to rotate, presenting new wearing surfaces, reducing abrading, and making it easier to advance the backhoe on the dragging outrigger pads.

The forces acting upon the pad tend to strip the pad off the foot. According to the present invention, the pad is preferably adhesively bonded to the foot, and the peripheral wall of the foot is provided with surface protrusions such as ribs or the like to reduce the side shear loads on the adhesive bond.

The present outrigger pad structure also includes a ball joint which utilizes an annular collar overlying the ball to increase the bearing area. The collar is associated with a releasable lock means such as a snap ring which allows the collar to be quickly removed so that a worn pad can be easily replaced.

Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawing.

DESCRIPTION OF THE DRAWING FIG. I is a side elevational view of a backhoe mounted on a tractor, only a portion of the tractor being illustrated;

FIG. 2 is a partial front elevational view of the backhoe of FIG. I, particularly illustrating the pair ofoutriggers;

FIG. 3 is an enlarged view taken along the line 3-3 of FIG. 2; and

FIG. 4 is an enlarged view taken along the line 44 of FIG. 3.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is illustrated a usual and conventional backhoe 10 attached to a vehicle or tractor 12. The backhoe 10 includes a bucket 14 attached by a bucket linkage 16 to an elongated dipstick 18. The dipstick in turn is connected by an element 20 to a boom 22 which is mounted to the backhoe frame for pivotal movement about a generally horizontal axis. This axis is defined by a pivot pin 24, as best seen in FIG. 1. As is well known to those skilled in the art, selective operation of a lift cylinder 26 and a crowd cylinder 28 manipulates the bucket 14 in a digging operation. i

During digging, the backhoe 10 is stabilized and supported by a pair of stabilizers or outriggers 30 which are pivotally connected at their upper extremities to the backhoe frame. The lower extremity of each outrigger 30 includes an outrigger pad structure and each outrigger 30 is raised and lowered by operation of an outrigger cylinder 34. The present invention is concerned with a particular pad structure 32.

More particularly, in a typical backhoe operation, the operator aligns the tractor 12 along a predetermined digging or work path and then actuates the outrigger cylinders 34 so that the padstructures 32 engage the supporting surface or roadway 36. Then, by operating the

cylinders

26 and 28, the operator lowers the bucket 14 and scoops out a bucketful of earth. After raising the bucket 14, the backhoe I0 is pivoted to one side or the other to dump the excavated material. This operation is repeated until a hole is dug of the desired depth.

Next the backhoe is advanced, that is, moved to the left, as viewed in FIG. 1, to enlarge the hole to form, for example, a trench for a drain line or the like. Al-

though it is possible to do this by actuating the cylin-' ders 34 to raise the pad structures 32 out of engagement with the roadway 36, and then rolling the backhoe to the left, this is not normally done because it takes too much time. Instead, the operator lowers the boom 22 until the element 20 rests upon the bottom of the trench. This has the effect of raising the backhoe slightly and pushing it to the left, as viewed in FIG. 1, moving the tractor l2 and dragging the pad structures 32 over the supporting roadway 36. When the cylinder 26 is extended to its maximum, theadvancement of the backhoe stops and its weight is again steadied by the outriggers 30. The digging phase :is repeated, and this cycle continued until the trench is finished. The progressive advancement of the backhoe 10 which occurs during this operation repeatedly drags the pad structures 32 over the roadway 36.

In the prior art the outrigger pads were generally rectangular steel plates which often had only one axis of pivotal movement and were therefore incapable of confonning to the grade of the roadway 36. Consequently, their sharp corners and edges would dig into the roadway 36 and damage it so that expensive replacement was required. Moreover, where adjacent structures such as curbings were very close. the prior art pad plates often struck and damaged such curbs so that they too had to be replaced.

In contrast to such prior art pads, the present pad structure 32 comprises, as best seen in FIGS. 3 and 4, a foot 38 made of tough material such as steel and having a generally circular base 40, a generally cylindrical peripheral side wall 42 and a central hub 44. A plurality of radial strengthening ribs 46 extend between the hub 44 and the side wall 42.

The side wall 42 is provided with a plurality of surface protrusions in the form of elongated, circumferentially spaced, and generally vertically extending ribs 48.

The pad structure 32 also includes a resilient pad 50 fitted over the base 40 and the side wall 42. The pad 50 is preferably made of rubber adhesively bonded to the foot 38 in close conformity with the ribs 48. The pad 50 is thus anchored to the ribs 48 so that shear loads imposed upon the pad 50 tend to be assumed by the ribs 48. This helps to preserve the adhesive bond and greatly reduces the incidence of stripping or tearing away of the pad 50 from the base 40 and side wall 42. It has been found in actual use that without the presence of the ribs 48 or equivalent anchoring surface protrusions. the hard use and rough treatment to which backhoe outrigger pads are subjected causes an accelerated failure of the adhesive bond between the pad 50 and the base 40 and side wall 42.

As seen in FIG. 2, the usual outrigger 30 is provided with a U-shaped swivel 52 at its end for pivotal movement of the conventional pad about a single axis defined by a transverse pin 54. In contrast, the present pad structure 32 is "universally" movable, that is, about many axes, and for this purpose comprises a mounting stud 55 whose upper end is rigidly secured by any suitable means (not shown) to the base of the U- shaped swivel 52, and whose lower end includes a spherical ball 56. The ball 56 forms part of a ball joint assembly which connects the pad structure 32 to the outrigger swivel 52.

The hub 44 includes an upwardly opening cylindrical cavity 58 having a hemispherical socket 60 in its bottom wall. The lower hemisphere of the ball 56 is seated in the socket 60 and is maintained in the socket 60 by an annular collar 62. The collar 62 is closely received within the cavity 58 in surrounding relation to the ball 56 and includes an inner annulus which is curved to fit in close conformity to the spherical contour of that portion of the ball 56 located just above the socket 60. In effect, the collar serves as a continuation of the socket 60 and provides extra bearing area.

The ball 56 is free to universally" pivot within the socket 60 and within the socket continuation formed by the collar 62. The open area of the cavity 58 above the collar 62 permits the foot 38 to pivot a greater amount before it engages the stud 55. Consequently, the pad structure 32 is able to accommodate steeper grades compared to prior art pads. and the increased bearing area provided by the collar 62 gives the added support needed in such situations.

The collar 62 is retained in operative position by releasable lock means in the form of a usual snap ring 64 which engages upon the upper outer periphery of the collar 62. The ring 64 is received with an annular retaining groove 66 in the hub 44. When it is necessary to remove the foot 38, perhaps to remove a worn pad and recap the foot with another pad, the snap ring 64 is quickly removable to allow the foot 38 to drop off the collar 62 and the stud ball 56.

The capability of the ball 56 for movement in virtually any direction permits the foot 38 to pivotally conform to the grade of the supporting roadway 36, and further permits the foot 38 to rotate about the longitudinal axis of the mounting stud 55. Therefore, the present pad structure is ideally suited to a backhoe operation in which the backhoe digs, slides forward, digs, and slides forward in a high-production sequence, without raising the outriggers. That is, the resilience of the pad structure 32 resists wear, the rounded configuration does not dig into and tear up roadways and curbs and, being able to rotate, the pad continually presents new wearing surfaces, thereby reducing any tendency of the pad to wear in one place, and reducing the dragging friction when the backhoe is successively advanced. The backhoe tends to roll on the rotating pads, as well as on the tractor wheels. In addition, the provision of shear bearing surface protrusions on the foot greatly reduces the tendency of the pad to be stripped away under high shear and impact loads, and the provision of the ball socket joint allows the foot to be quickly removed for replacement of worn pads and the like.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

I claim:

1. In a vehicle having a plurality ofoutriggers to support and stabilize the vehicle during the intervals when the vehicle is stationary between progressive advancements of the vehicle along a predetermined work path, an improved outrigger pad structure on each of said outriggers comprising:

a foot including a generally circular base and a generally cylindrical peripheral wall, said wall having a multiplicity of surface protrusions",

a resilient pad fitted over and bondedto said base and said wall and anchored in position on said wall by said surface protrusions; and

ball joint means connecting said foot to the outrigger and operative to permit said foot to pivotally conform to the grade of the supporting surface, and further operative to permit said foot to rotate about a generally vertical axis.

2. Outrigger pad structure according to claim I wherein said pad is made of rubber adhesively bonded to said foot.

3. Outrigger pad structure according to claim 1 wherein said surface protrusions comprise a plurality of elongated, circumferentially spaced, and generally vertically extending ribs.

4. Outrigger pad structure according to claim 1 wherein said ball joint means comprises means on said foot defining a centrally located hemispherical socket; a mounting stud sttached to the outrigger and having a spherical ball portion received in said socket; a collar in surrounding relation to said ball portion and retaining said ball portion in said socket; and releasable lock means securing said collar in said surrounding relation.

5. Outrigger pad structure according to claim 1

Claims

1. In a vehicle having a plurality of outriggers to support and stabilize the vehicle during the intervals when the vehicle is stationary between progressive advancements of the vehicle along a predetermined work path, an improved outrigger pad structure on each of said outriggers comprising: a foot including a generally circular base and a generally cylindrical peripheral wall, said wall having a multiplicity of surface protrusions; a resilient pad fitted over and bonded to said base and said wall and anchored in position on said wall by said surface protrusions; and ball joint means connecting said foot to the outrigger and operative to permit said foot to pivotally conform to the grade of the supporting surface, and further operative to permit said foot to rotate about a generally vertical axis.

2. Outrigger pad structure according to claim 1 wherein said pad is made of rubber adhesively bonded to said foot.

5. Outrigger pad structure according to claim 1 wherein the vehicle is a backhoe.