US3407945A - Locking means for offset backhoe - Google Patents

Description

Oct. 29, 1968 v A. H. LEESE I 3,407,945

LOCKING MEANS FOR OFFSET BACKHOE Filed Dec. 7, 1966 5 Sheets-Sheet l INVENTOR 4450?? fif 142s:

AE'MJ Oct. 29, 1968 A. H. LEESE LOCKING MEANS FOR OFFSET BACKHOE 5 Sheets-Sheet 2 Filed Dec. 7, 1966 INVENTOR A1554? h. 1:21;: I er ATTORNEY United States Patent x v 3,407,945 LOCKING MEANS FOR OFFSET BACKI IOE Albert Harold Leese, Basildon, England, assignor to Ford .Motor Company, Dearborn, Mich., a corporation of Delaware Filed Dec. 7, 1966, Ser. No. 599,770

4 Claims, (Cl. 214-138) ABSTRACT OF THE DISCLOSURE A locking means for the carriage of an adjustable offset backhoe of the type including a transverse frame having a pair of C-shaped slots and expansible blocks within the slots for supporting the carriage and holding it against movement along the slots is actuated by tightening the bolts holding the carriage against the frame. Preferably, a cam surface on each of the blocks laterally expands the blocks upon tightening the bolts so that the blocks tightly engage opposing side walls of the C-shaped slots.

This invention relates to offset backhoes.

Tractor-mounted adjustable offset backhoes often are provided with a frame extending transversely of the rear of the tractor and forming a track along which a carriage supporting thebackhoe boom may be moved to position the backhoe to either side of the tractor. Clamps, including bolts carried by the carriage, engage the track to hold the backhoe at any set position along the length of the track.

In the backhoe of the present invention, the track consists of a pair of horizontally-extending, rearwardly-opening C-shaped slots in the transverse frame which receives clamping blocks and bolts, the threaded end of each of which projects through the slot and is received in a bore in the carriage. Upon tightening a nut on each bolt against the carriage, the carriage is securely clamped against displacement along the track.

The improved clamping mechanism includes blocks within the C-shaped slots which, upon tightening the clamping bolts, laterally expand to span across the inner walls of the slot and secure the carriage against loosening and movement as the backhoe is operated.

Among the objects of the present invention is to provide an improved backhoe construction in which the carriage clamp does not tend to loosen during operation; to provide such a construction in which the carriage is firmly clamped without the necessity of tightening auxiliary bolts or wedgers; and generally to improve mechanisms of the type described.

Other objects, and objects relating to details and economies of construction and use will be more apparent from the detailed description to follow.

My invention is clearly defined in the appended claims. In the claims, as well as in the description, parts may at times be identified by specific names for clarity and convenience, but such nomenclature is to be understood as having the broadest meaning consistent with the context and with the concept of my invention as distinguished from the pertinent prior art. The best form in which I have contemplated applying my invention is illustrated in the accompanying drawings forming a part of this specification in which:

FIGURE 1 is an isometric view of a tractor with backhoe and loader attached, only the rear portion of the tractor and loader being shown.

FIGURE 2 is a side elevation of the backhoe unit, the

boom being broken away and the dipstick and bucket not being shown. Portions of the hydraulic hoses are broken away for convenience of illustration, and a portion of the frame is broken away to show details of interior construction.

FIGURE 3 is an enlarged elevation of the clamping mechanism for clamping the carriage in any adjusted p0 sition along the frame, portions of the frame being broken away or shown in vertical section and portions of the carriage being broken away.

FIGURE 4 is a perspective view of the bolts, clamping blocks and associated parts for clamping the carriage in any adjusted position.

Referring to FIGURE 1, the backhoe of the present invention is adapted for mounting on a tractor 11. The backhoe comprises a boom 12, a dipstick 14 and a bucket 15 which are articulated and operated in the usual manner. The boom 12 is pivotally mounted for vertical swinging movement on a swing frame 16, which is supported for horizontal swinging movement on a rotary cylinder 17 supported by a carriage 19. The boom 12, dipstick 14 and bucket 15 are operated in the customary manner by hydraulic cylinders 20*, 21 and 22, respectively. Operation of these cylinders is controlled by a bank 24 of manually operated hydraulic control valves connected with the cylinders 20', 21 and 22 by hoses 23.

The backhoe 10 is supported on the tractor 11 by a main frame 25 secured to the chassis of the tractor. The main frame 25 extends between the rear wheels of the tractor, one wheel 26 being shown and projects somewhat behind the wheels, terminating in a vertical, relatively flat rear face 27 provided with a pair of vertically-spaced, parallel, horizontal, rearwardly-opening C- shaped slots extending from side to side of the tractor and supporting the carriage 19, as will be described. A pair of stabilizers 30 and 31 are pivotally mounted on the lower portion of the main frame 25 and may be lowered during use of the backhoe to aid in stabilizing the tractor 11 against overturning and to take the weight off the rear wheels of the tractor.

A rearwardly facing operator seat is mounted on the backhoe main frame 25 adjacent the valve bank 24.

Referring now more specifically to FIGURES 2 and 3, the backhoe main frame 25 preferably is a welded assembly of parts including four channels 34, each of the channels extending transversely from side to side of the tractor and being arranged in pairs with facing spaced flanges 35 forming the lips of the C-shaped slots 29. The outer surface of the rear flange 35 lies generally in the plane of the rear face 27 of the main frame, as indicated in FIGURE 3. The webs 36 of the channels 34 extend forwardly from the rear face 27 of the main frame and form the opposite side faces of the C-shaped slots 29. Preferably, a plate 37 extending between the webs 36 of each pair of flanges forms the bottom of each C- shaped slot 29 and holds the flanges against spreading due to clamping action against the webs 36, as will be explained.

The carriage 19 is supported on the rear face 27 of the main frame 25 and clamped in any adjusted position along the C-shaped slots 29 by the clamping mechanism best shown in FIGURE 4. This clamping mechanism comprises a first block 39 adapted to be received within each C-shaped slot 29 and having a hole 40 adjacent each end for closely receiving a bolt 41. Two bolts 41 project through each C-shaped slot 29, extend beyond the rear face 27 of the main frame and. are received within bores 42 in the carriage 19. Nuts 44 on the bolts 41 serve to clamp the carriage in any adjusted position along the C-shaped slots, as indicated in FIGURE 3.

A second block 45 is located within each C-shaped slot 29, the second block having a rearwardly tapering hole 46 adjacent each end to receive bolts 41, the blocks 45 preferably having a stepped or offset cross section to locate the offset portion 47 of the block in the general plane of the block 39 (see FIG. 3). A bushing 49 is received on each bolt 41 between the blocks 39 and 45 3 and is provided with a conical or tapering outer periphery 50 coacting with the holes 46 of the block 45.

The arrangement is such that as the nuts 44 are tightened, the blocks 39 and 45 will be drawn together, the block 39 carrying the bushings 49 into engagement with the block 45 so as to laterally expand the assembly of blocks 39 and 45, In addition, the rear face 51 of each block 45 preferably is provided with converging upper and lower surfaces generally matching the taper of the flanges 35 forming the lips of the C-shaped slot. Thus, upon tightening the nuts 44, not only is the carriage 19 firmly clamped against the rear face 27 of the main frame, but the outer edge portion of the block 39 and the opposite, offset portion 47 of the block 45 also is pressed outwardly into firm engagement with the opposite side faces of each C-shaped slot so as to lock the above-described clamping assembly against any movement within the C- shaped slots and thereby prevent loosening of the clamps and unintended movement of the carriage 19 along the slots. At the same time, upon loosening nuts 44, the blocks 39 and 45 will separate slightly, thus loosening the clamping means and permitting ready adjustment of the carriage along the slots. The plate 37 extending between the webs 36 of each pair of channels prevents spreading of the channels by the outwardly-pressed blocks 39 and 45.

I claim:

1. In an adjustable offset backhoe in which a backhoe boom is supported on a tractor by a carriage slidable along a track carried by a frame on the rear of the tractor, the improvement comprising: the track being formed by a frame having members defining two spaced, parallel rearwardly-opening, C-shaped slots extending across the rear of the tractor, bolts extending from the slots and 4 received within holes in the carriage and adapted to be tightened to draw the carriage against the frame, a block within each slot and engaged by at least one of the bolts, the block having two complementary portions adapted to be cammed laterally outwardly upon tightening of the bolt so as to cause the block to laterally expand and wedge between opposite walls of the C-shaped slot and to clamp the block against the inner face of the margins of the slot.

2. In an adjustable offset backhoe as claimed in claim 1, the members defining each of the slots comprising two parallel, transversely extending channels having facing, spaced flanges defining the margins of the slot.

3. In an adjustable offset backhoe as claimed in claim 2, the mid-portion of the flanges of the channels defining each slot being joined by a plate forming the bottom of the slot and aiding in preventing spreading of the channels due to outward force of the blocks.

4. In an adjustable offset backhoe as claimed in claim 1, one of the blocks being laterally fixed relative to the bolt and the other block having a tapering hole receiving the bolt, and a cooperating tapering member carried into engagement with said tapering hole by said one block to center the hole of said other block about said bolt, centering movement of said other block serving to press the lateral edges of the blocks outwardly into firm engagement with the opposite side faces of the slot.

References Cited UNITED STATES PATENTS HUGO O. SCHULZ, Primary Examiner.

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