ARRANGEMENT IN A LOADING BUCKET

Abstract: A loading bucket (16) is movably connected to an L-shaped supporting yoke (10) and maintained thereon by means of rigid link arms (21) which are pivotally connected to the lower rear end of the loading bucket and to a point which is located on a higher level on the columns (11) of the supporting yoke. At the front end of the lower forwardly directed fork tunnels (12) of the supporting yoke, there are provided support rollers (15) which cooperate with the loading bucket and allow forward displacement thereof when the supporting yoke is tilted slightly forwardly for emptying the loading bucket. The centre of mass of the empty loading bucket is situated between a vertical plane through the support rollers (15) and a plane defined by the columns (11), when the fork tunnels (12) are horizontal.

Description: ARRANGEMENT IN A LOADING BUCKET The present invention relates to an arrangement in a loading bucket of the type stated in the preamble of the main claim. Loading buckets of this type are often used for clearing snow and handling bulk material, such as grain and wood chips, by means of a fork-lift truck. Examples of such known devices are given in Swedish published patent application SE-A-8206412-2, German Offenlegungsschrift DE-A-2,210,082, and U.S. patent specifications US-A-2,482,692 and US-A-3,656,643. A common feature of these buckets is that they can be emptied by being tilted forwards such that the load will slide off from the bucket. The buckets are emptied and returned to starting position either hydrau- lically or mechanically. Entirely hydraulically operat¬ ed buckets have also been suggested, in which the rear edge is raised by means of a hydraulic piston and cylinder assembly for emptying the bucket. One example of devices of * this type is given in German Offenlegungs- schrift DE-A-1,909,542. A common drawback of the buckets disclosed in Swedish patent application SE-A-8206412-2 and German Offenlegungsschrift DE-A-2,210,082 is that the buckets must be lowered to the ground before they can be re- turned to starting position after emptying. Another drawback inherent in these two prior art devices is that the forks of the fork-lift truck will move into the loading space of the loading bucket during emptying of the bucket. Also, these buckets do not have entirely smooth bottoms, which may be disadvantageous in uses other than handling of bulk material and snow. Although these known buckets comprise but a few mechanical parts, they are relatively difficult to operate. The hydraulically driven buckets have a separate hydraulic equipment, or the hydraulic equipment is connected to the hydraulic system of the fork-lift truck. This renders the equipment considerably more expensive and also makes it impossible to use and operate the equipment by means of fork-lift trucks having no hydraulic system. In the mechanical variants of known loading buckets, the conventional system is also such that the centre of mass during transport of a filled bucket will be situat¬ ed well forward on the forks, thus making the fork- lift truck front-heavy and difficult to manoeuvre. Another drawback is that the tilting movement for emptying the bucket in these prior art mechanical devices is interrupted by a non-resilient stop, which causes heavy wear on the truck. If, on the other hand, use is made of a resilient stop for interrupting said tilting movement, the construction will become more expensive to manufacture. One object of the present invention is to elimi¬ nate or reduce the above-mentioned shortcomings in¬ herent in prior art devices. Another object of the invention is. to provide an arrangement which comprises but a few movable parts, yet ensuring a reliable func- tion, and is easy to manoeuvre. The above-mentioned further objects of the inven¬ tion are achieved by giving the arrangement the fea- tures recited in the main claim. Particularly advan¬ tageous embodiments of the arrangement according to the invention are recited in the subclaims. The invention will be described in greater detail hereinbelow with reference to the accompanying draw¬ ings. Fig. 1 is a side view of the arrangement accord¬ ing to the invention. Fig. 2 is an end view of the arrangement as seen from the rear. The arrangement according to the invention com¬ prises a rigid L-shaped supporting yoke 10 having two upwardly directed columns 11 and two lower, forward- ly directed fork tunnels 12. The L-shaped members formed of the fork tunnels and the columns are rigidly interconnected by means of a suitable cross-beam 13. The columns and the fork tunnels suitably consist of box girders. At their rear ends, the fork tunnels 12 have an opening 14 to allow the insertion of the forks of a fork-lift truck. At their front ends, the fork tunnels are provided with support rollers 15 which project but slightly above the upper planes of the fork tunnels. The support rollers may consist e.g. of sealed needle bearings the outer rings of which serve as support rollers. The arrangement further comprises a loading bucket 16 which in the illustrated embodiment is open at the top and forwardly and whose bottom 17 bears on the support rollers 15 and has its front end curved downwardly to serve as a ramp to the loading bucket. At the lower rear end of the loading bucket, there are provided projecting bearing lugs 18 each of which supports a journal 19. At the upper ends of the columns, there is provided a shaft 20 which extends through suitable bearing, bushings in the column and which at the outside of the solu ns is rigidly connected to one end of link arms 21 the other ends of which are pivotally mounted on a respective one of the jour¬ nals 19. The arrangement further comprises locking de¬ vices 22 which may be of a very simple construction and consist of latches which are mounted each on a column 11 and can be brought into locking engagement with a suitable projection on the rear side of the bucket. The function of the loading bucket appears from Fig. 1. When the fork tunnels 12 are in a horizontal position and the locking bucket is empty, the centre of mass of the bucket is located at a point between the columns 11 and a vertical plane extending through the support rollers 15. Thus, even if the bucket 16 is not locked by the locking devices 22, it will assume a stable resting position shown by full lines in Fig. 1. If the supporting yoke 10 is tilted forwardly down¬ wardly, as intimated by dash-dot lines, the bucket will slide forwardly over the support rollers 15 as at the same time the rear end of the loading bucket is swung upwardly by the intermediary of the link arms 21. Since the link arms are rigid, the forward movement of the bucket will be gently stopped at the position of emptying which is shown by dash-dot lines and at which the link arms 21 and the bottom 17 of the bucket form a straight line between the shaft 20 and the support rollers 15. It is here particularly advantageous if the length of the link arms, as shown in the drawings, amounts to approximately half the distance between the shaft 20 and the support rollers 15. At the beginning of the emptying operation, the rear end of the bucket is quickly raised while the movement of the bucket is interrupted at the position of emptying or position of equilibrium in a gentle manner and, possibly, with a certain oscillation about this position of emptying, i.e. the journals 19 may move upwardly in relation to the position shown by broken lines. This gives an advantageous tossing motion when emptying bulk goods. As soon as the loading bucket has been emptied and the yoke 10 starts returning to the position shown in full lines or is swung further rearwardly, the loading bucket 16 is caused to return to its starting position. If the loading bucket should be used for other purposes than for bulk goods, snow or the like, the bucket can be locked in its rear position by the lock¬ ing devices 22. The bucket may then be used e.g. for handling pallets which can be placed in the bucket for transportation in a factory or the like. The bucket may have a substantial size, e.g. a width of 2.6 m, a depth of 2.1 m and a height of 1 m. Because of such dimensions, several pallets can be placed beside each other in the bucket. During normal transport of a loaded bucket which is not locked by means of the latches 22, the yoke is preferably tilted slightly rearwardly, as is custo¬ mary in the handling of pallets by means of fork-lift trucks. In snow clearing or loading of bulk goods, the bucket is tilted slightly forwardly such that the downwardly directed ramp of the bucket engages the ground. When the fork-lift truck is driven for¬ wards, the bucket will be pressed up to the position shown in full lines in Fig. 1, and when the bucket is full, the supporting yoke returns to the position shown in full lines or is tilted slightly rearwardly. As mentioned above, the bucket is emptied by tilting the supporting yoke forwardly, whereby the bucket will slide forwardly on the ■ ■support rollers 15. At the same time, the rear end of the bucket is swung upwardly, as are the link arms. Since these execute a pivotal movement, the braking effect at the extreme position will be gentle. Especially in the case of a heavily loaded bucket, the rear edge of the bucket and the link arms may pivot upwardly to a slightly greater extent than what is shown by dash-dot lines. This results in an oscillation about the position of equilibrium shown by dash-dot lines, thus facilitat- ing emptying of the bucket. The drawings show only one embodiment of the invention, many modifications being possible within the scope thereof. Thus, the bucket need not have the illustrated design with obliquely cut side walls, and the bucket may have e.g. a top cover and an open front end. It is however essential that it be ensured that the centre of mass of the empty bucket is situated behind a vertical plane through the support rollers 15, preferably far behind such vertical plane. Further, the shaft 20 may be replaced by separate journals for each link arm but, in such a case, use should instead be made of a through shaft replacing the jour¬ nals 19, such that parallel guiding is obtained in this case as well. In the illustrated embodiment, the connection of the link arms to the loading bucket is disposed as far down as the lower rear edge of the bucket. Similarly, the upper end of the link arm has been mounted as far up as the upper end of the column. It is however possible within the scope of the invention to provide these articulations adjacent the lower rear end edge of the loading bucket and adjacent the upper ends of the columns. In the il¬ lustrated embodiment, the dimensions of the columns, fork tunnels, link arms and the bucket are such that the columns, the fork tunnels and a line between the support rollers and the shaft 20 form approximately a right-angled triangle having internal angles of 30 , 60 and 90 , the columns 11 forming the shorter leg and the fork tunnels 12 the longer leg of triangle. If such dimensions are maintained, it is conceivable with¬ in the scope of the invention to extend the columns 11 upwardly beyond the shaft 20, if so required for any purpose which is not related to the emptying and filling functions of the bucket. The angular arrangement illu¬ strated is the preferred one but other angular arrange¬ ments are conceivable, although the columns 11 and the fork tunnels 12 preferably are at right angles to each other. A further modification within the scope of the inven¬ tion is to provide the bucket with guides for the support rollers so as to maintain a connection between the fork tunnels and the bucket during the movement of the bucket. One possibility then is to provide the underside of the bucket with four U-beams which by pairs have their flanges directed towards each other to serve as guides for support rollers on each side of the associated fork tunnel.

Claims: CLAIMS 1. An arrangement in a loading bucket (16) which is connected to and movable in relation to a supporting yoke (10) having rear, upwardly directed columns (11) and lower, forwardly directed fork tunnels for receiv- ing the forks of a fork-lift truck, by means of which forks the supporting yoke and the loading bucket are intended to be transported and operated, said arrange¬ ment comprising anchoring means (21) adapted, when the loading bucket is emptied by tilting thereof, to prevent the loading bucket from being separated from the supporting yoke, and support rollers (15) adapted to cooperate with the loading bucket (16) and disposed at the free front ends of the fork tunnels (12), c h a r a c t e r i z e d in that the anchoring means (21) consist of rigid link arms (21) which ex¬ tend between a point, adjacent the lower rear end of the loading bucket and a point (20) located on a higher level on the columns (11) and are pi otally connected to the columns and the loading bucket, and that the loading bucket has such mass distribution when it is empty that the centre of mass of the empty bucket is situated between a vertical plane extending through the support rollers (15) and a plane defined by the columns when the fork tunnels are horizontal, in order that the loading bucket, when the fork tunnels are inclined in the direction of tilting for emptying, should slide forwardly on the support rollers (15) as at the same time the rear end of the loading bucket is swung upwardly by the intermediary of the link arms (21). 2. Arrangement as claimed in claim 1, c h a ¬ r a c t e r i z e d in that the link arms (21) extend between a point adjacent the upper ends of the columns and the lower rear end edge of the loading bucket. 3. Arrangement as claimed in claim 1 or 2, c h a ¬ r a c t e r i z e d in that the columns (11), the fork tunnels (12) and a line between the support rollers (15) and the pivot connections (20) of the link arms (21) to the columns (11) form approximately a right- angled triangle having internal angles of 30 , 60 and 90 , said columns forming the shorter leg of the triangle and said fork tunnels forming the longer leg thereof. 4. Arrangement as claimed in claim 1, 2 or 3, c h a r a c t e r i z e d in that the length of the link arms (21) is approximately half the distance between the pivot connections (20) of the link arms to the columns (11) and the support rollers (15) pro- vided on the fork tunnels (12). 5. Arrangement as claimed in any one of the pre¬ ceding claims, c h a r a c t e r i z e d in that the loading bucket (16) has guides for the support rollers (15) .

Inventors: GRIBERG BENGT GEORG, GRIBERG, BENGT, GEORG
Applicants: GRIBERG BENGT GEORG, GRIBERG, BENGT, GEORG
Application year: 1985
Main classification: B66F9
IPC codes: B66F9