SKEWING ATTACHMENT FOR WHEEL-MOUNTED LOADERS, TRACTORS, OR LIKE MACHINES

Abstract: Attachment for wheel-mounted loaders, tractors, and like machines, the attachment being mounted between the normal coupling of the loader and the connection points on an implement, for skewing the implement in a plane transversely of the travelling direction of the loader. The attachment is adapted, at its front end, to be fixedly mounted on an existing implement and, at its rear end, to be hooked on and secured to said loader, on the one hand by means of fixed pins in hooks and, on the other hand by means of movable fixation pins in associated fixation lugs mounted on a connecting plate (16).

Description: SKEWING ATTACHMENT FOR WHEEL-MOUNTED LOADERS, TRACTORS, OR LIKE MACHINES The present invention relates to an attachment for wheel-mounted loaders, tractors, or like machines, said attachment being mounted between the normal coupling of the loader and the connection points on an implement, for skewing the implement in a plane transversely of the travelling direction of the loader. Attachments for the skewing of vehicle-borne imple¬ ments are known from, for example, U.S. patent specifi¬ cations 3,182,831, 2,924,345, 2,932,101 and 3,599,819, of which the first two publications show arrangements similar to that of the present invention. However, these two prior art arrangements are technically more compli¬ cated and, consequently, more expensive than that of the present invention. Furthermore, after the arrangements according to these publications have been in operation for some time, the lost motion due to wear of the components may be considerable. The two last-mentioned publications relate to arrangements for side dumping of excavated loads, and these arrangements are not dimensioned to have full breaking-up capacity when the skewing equipment is operated. The object of the present invention is to eliminate these difficulties and problems, and a loader which is driven over broken ground, e.g. forest ground, will have full loading and breaking-up capacity also during skewing of the attachment, regardless of the skewing angle. The invention presents a solution to the above- mentioned problems and drawbacks, and also a number of interesting solutions aiming at economy of manufacture and economic use of the attachment. The invention will be described in greater detail hereinbelow, reference being had to the accompanying drawings illustrating preferred embodiments. Fig. 1 is a view of the attachment as seen from behind and mounted on a so-called grate bucket or stone fork. Fig. 2 is a view along line A-A in Fig. 1. Fig. 3 shows a screw joint for controlling the skewing, along line B-B in Fig. 1. Fig. 4 is a section along line C-C in Fig. 1. Fig. 5 shows an example of a toggle mechanism to be mounted on the skewing attachment according to the invention. The attachment 1 according to the invention for wheel loaders comprises a pivot plate 12 made of heavy steel sheet and connected to the loader unit of the wheel loader, to which pivot plate a plurality of spacer brackets 13 recessed for screw joints 11 adapted to guide the skewing movements of an implement 3, are welded and adapted to uniformly take up the stress upon the construction at, for example, breaking-up loads. The skewing movement is centered by means of a bolt joint 7 disposed centrally on the pivot plate 12 and symmetrically in relation to arcuate guiding grooves 8 for the screw joints 11. The rear end 4 of the attachment 1 comprises two connecting. plates 16 welded to the spacer brackets 13 and substantially conforming to the guiding grooves 8, to which connecting plates 16 fixed hooks 5 and fixation lugs 6 are, in turn, welded so as to allow for snap-on coupling to the loader unit, by means of fixed pins in the hooks 5 and by means of movable fixation pins in the fixation lugs 6. The attachment is adapted to be fixedly mounted on the implement 3 by means of the screw joints 11 running in the grooves 8 and extending through strong bushings 9 fixedly mounted on the implement, said screw joints being tightened so as to be slidable between the pivot plate 12 and wearing washers 10 on the main beams of the implement. It should be observed that these wearing washers are made of steel softer than the rest of the construction, and therefore they are worn out first and are easily replaced. The arrangement, i.e. the skewing attachment 1 and the implement fixedly mounted thereon, is operated by at least one hydraulic cylinder 14 which is connected to the pivot plate 12 at 17 and to the implement 3 at 18. It should here be mentioned that an existing implement is easily convertible for mounting of a skewing attachment in that strong bushings 9 accord- ing to the invention are mounted on the main beams of the implement, and mountings for the hydraulic cylinder(s) are provided at 18. The screw joints 11 are thus provided in strong bushings which are welded to the main beams of the implement. The clear space of the bushings has been widened to the dimension of the screws to extend there¬ through. At the rear end 20 of each screw, a special washer 19 is mounted which is designed such that it runs in the groove 8 in a specific manner. As shown in Figs. 3 and 4, the washer 19 has two planes of symmetry, one along a line straight through the screw transversely of the extension of the groove 8 and the other along the tangent line of the groove through the screw bolt. The hole in the pivot plate 12 fits a shoulder which projects from the washer and which also is un- symmetric in the manner described above. The washer is designed to be slidingly guided in the groove 8 such that the washer goes clear of the spacer brackets 13 when the attachment is operated. Finally, it should be stressed that the attachment is designed and dimensioned to hold, for example, so- called stone forks or grate buckets, excavation buckets or any implements intended for wheel loaders. The attach¬ ment is further dimensioned for breaking-up loads and similar loads in any skewing position to the full capacity of the wheel loader. If a very powerful skewing moment is desired, the attachment can be operated by a toggle mechanism 15 (Fig. 5). Moreover, the operating cylinder(s) of the attachment can be hydraulically connected to a safety valve 21 (so-called shock valve) (Fig. 6) to protect the cylinder(s) on extreme overloading of the attachment.

Claims: CLAIMS 1. An attachment for wheel loaders, .adapted to be mounted between the normal implement coupling of the loader and the connection points on an implement (3), for skewing the implement in a plane transversely of the travelling direction of the loader, said attachment being adapted, at its front end (2), to be fixedly mounted on the implement (3) and, at its rear end (4), to be hooked on and secured to the implement coupling, on the one hand by means of fixed pins in hooks (5) and, on the other hand, by means of movable fixation pins in associated fixation lugs (6) mounted on a connecting plate (16), c h a r a c t e r i s e d in that the skewing movement of the attachment (1) is centered on a centrally disposed, strong bolt joint (7), and that the movement is guided by screw joints (11) arranged in through grooves (8) in a pivot plate (12), running in the grooves (8) and extending through strong bushings (9) fixedly mounted on said implement, said screw joints being tightened so as to be slidable between said pivot plate and wearing washers (10) arranged on the main beams of the implement. 2. A skewing attachment as claimed in claim 1, c h a r a c t e r i s e d in that the load applied to the implement (3) is transmitted to and uniformly taken up by the attachment (1) via said screw joints (11) and a plurality of spacer members (13) arranged above the screw joints and the grooves (8), welded to the pivot plate (12) and recessed for the screw or nut and the wearing washers (10) of said screw joint (11), and that the attachment (1) is loadable to its utmost capacity regardless of skewing movements within an angle of say + 15°. 3. A skewing attachment as claimed in claim 1 and 2, c h a r a c t e r i s e d in that mounting on existing can be carried out easily by providing a small number of fixation members (5, 6) (in Fig. 1 at 18) on said implement, on the one hand for fastening and mounting and, on the other hand, for operating the implement. 4. A skewing attachment as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that skewing can be hydraulically operated by at least two hydraulic cylinders (14) arranged between said attachment and said implement. 5. A skewing attachment as claimed in claim 5, c h a r a c t e r i s e d in that, if more power is required for the hydraulic operation of the skewing movement, the hydraulic cylinders can be connected to a toggle mechanism (15). 6. A skewing attachment as claimed in anyone of the preceding claims,, c h a r a c t e r i s e d in that skewing is operated by two hydraulic cylinders (14) which are hydraulically interconnected via a double- acting safety valve (21), a so-called shock valve so as to protect the hydraulic cylinders on extreme over¬ loading of the skewing attachment.

Inventors: LARSSON KARL GUSTAV GUNNAR, LARSSON, KARL, GUSTAV, GUNNAR
Applicants: VRETEN AB
Application year: 1986
Main classification: B66F9
IPC codes: E02F3