FORK BODY

Abstract: The invention relates to a lift fork rack (1) which comprises a first beam (5), a second beam (10) and at least two spacer elements (15, 20), which fix the first and second beams (5, 10) at a distance from and substantially parallel to each other. The load-bearing fork members (40, 45; 40', 45') can be mounted on the first and second beams (5, 10). The fork members (40, 45; 40', 45') can be displaced along the length of the beams (5, 10). The spacer elements (15, 20) have fastening means (80, 85) which are intended to releasably fasten the lift fork rack (1) to a lift mechanism (75). The upper beam (5) has a web (35) and a flange (25) which are joined to each other at an angle alpha different from 90 DEG . The upper beam (5) is joined to each spacer element (15, 20) via the web (35). The web (35) is directed away from the lower beam (10).

Description: 2 The purpose of the present invention is to achieve a lift fork rack and a fork member of the type described by way of introduction which provides a large field vision for an operator when the lift fork rack is mounted on the lift mechanism of the vehicle. Another purpose of the present invention is to achieve a lift fork rack which has high fatigue strength. An additional purpose of the present invention is to achieve a lift fork rack which permits loading and unloading of an object on an inclined surface. This is achieved according to the invention by virtue of the fact that the upper beam has a web and a flange which are joined to each other at an angle α differing from 90°, that the upper beam is joined to each spacer element via the web, and that the web is directed away from the lower beam. By making the web of the first beam inclined, the flange will be displaced downwards towards the lower beam. This means that the operator will be better able to see the fork members mounted on the rack when the lift mechanism is in its lower position. According to one embodiment, the fork members are displaceable relative to the coupling means, which connect the fork members to the lift fork rack, to permit loading and unloading on inc lined surfaces. The invention will be described in more detail below with reference to examples shown in the accompanying drawings, where Fig. 1 shows a perspective view of a lift fork rack with fork members mounted on the rack, Fig. 2 shows a front view of a lift fork rack with fork members mounted on the rack, Fig. 3 shows a side view of a lift fork rack, Fig. 4 shows a perspective view of a lift fork rack, and 3 Fig. 5 shows a side view of a lift fork rack with fork members mounted on the rack and being displaceable relative to a coupling means. Figs. 1- 4 show a lift fork rack 1, which comprises an upper beam 5 and a lower beam 10, which are fixed spaced from and essentially parallel to each other by means of two spacer elements 15, 20. The upper beam 5 has a flange 25 provided with a web 35. The lower beam 10 is a T-beam. For strength considerations it is important that the anchoring points of the upper and lower beams 5, 10 to the respective spacer elements 15, 20 be arranged at a substantial distance from each other. This means, however, that the upper beam 5 will limit the field of vision of an operator of the vehicle on which the lift fork rack 1 is mounted. In order to solve this problem, the web 35 of the upper beam 5 is made inclined, which means that the flange 25 will be displaced relative to the second beam 10. The upper beam 5 has a cross-section substantially in a V-shape. This means that the web is joined to the flange 25 of the upper beam 5 at an angle α which is not 90°. Preferably this angle α lies in the interval 40° - 50°. The web 35 is directed into the respective spacer elements 15, 20 and the flange 25 is free of the respective spacer elements 15, 20. By virtue of the fact that the flange 25 is displaced towards the lower beam 10, the field vision of the operator is increased. The operator is provided with a larger overview of the fork members 40,45 mounted on the lift fork rack 1, making it easier for the operator to aim the fork members 40,45 under the object to be lifted and to place the object where it is to be left. As can best be seen in Figs. 3 and 4, the upper beam 5 is joined to the respective spacer elements 15, 20 by means of the web 35. The web 35 of the upper beam 5 is inserted into a slot 55 in each spacer element 15, 20. This joint provides high fatigue strength in the joint between the upper beam 5 and the spacer elements 15, 20. The fatigue strength can be increased further by rounding the bottom of the slot 55. 4 The web 35 of the upper beam 5 thus extends obliquely upwards towards the hook 80, and the flange 25 of the upper beam 5 substantially extends in a vertical plane. Vertical plane in this context means the plane perpendicular to a horizontal surface on which there rests, for example, a pallet to be lifted by means of the lift fork rack. The lower beam 10, which is made as a T-beam, has a web 60 which is joined to the respective spacer elements 15, 20. A second slot 65 is made in each spacer element 15, 20 into which the web 60 is inserted. In order to reduce the concentrations of stress, the bottom of the second slot 65 is rounded. A heel 70 is arranged on each spacer element 15. 20 and is joined both the web 60 and to the respective spacer elements 15, 20. The spacer elements 15, 20 are arranged at a substantial distance from each other and form together with the upper and lower beam 5, 10 a frame. The distance be- tween the spacer elements 15, 20 is also dependent on the design of the lifting mechanism 75 to which the lift fork rack 1 is to be coupled. Each spacer element 15, 20 comprises attachment means in the form of a hook 80 and an opening 85. The hook 80 is designed to be hooked on a lifting mechanism 75 which has a pin 90 designed to be inserted into the opening 85 (Fig. 3). As can best be seen in Fig. 1, on the lift fork rack 1 ύiere are preferably mounted two fork members 40,45, such as pallet fork members, each having first and second legs 95, 100. The first 95 and the second 100 legs form essentially a right angle with each other, the first leg 95 having coupling means 105 for coupling together with the upper and lower beams 5, 10 of the lift fork rack 1. The coupling means 105 is joined to the first leg 95 and is coupled to the flange 25 of the upper beam 5, and the first leg 95 at the same time abuts against the flange 110 of the lower beam 10. The second leg 100 has a load surface 115 for carrying a load. In order to be able to lift objects of different shapes, the distance between the fork members 40,45 can be changed. The flange 25 of the upper beam 5 comprises a plurality of notches 120 along its length. These notches are intended to determine the positions of the fork members 40,45 and cooperate with the coupling means 105 to fix the fork members 40,45 laterally. If, for example, long objects are to be lifted, it is suitable that the distance between the fork members 40,45 be great to distribute the load. Preferably both the upper and the lower beams 5,10 extend laterally to either side of each spacer element 15, 20 to make possible a large distance between the fork members 40,45. If smaller objects are to be lifted, the distance between the fork members 40,45 should be small. When the distance between the fork members 40,45 is small, the field of vision of the operator will be limited by the first legs 95 of the fork members 40,45. In order to solve this problem, the first and second legs 95, 100 extend in separate planes. The fork members 40,45 are arranged so on the lift fork rack 1 that the distance between the first legs 95 is greater than the distance between the second legs 100. According to an alternative embodiment, which is shown in Fig. 5, the respective fork members 40', 45' can be made displaceable relative to the coupling means 105' in the longitudinal direction of the first leg 95'. The coupling means 105' is coupled to the upper and the lower beams 5, 10. The coupling means 105' has an elongated opening 125 in which a pin 130 mounted on the first leg 95' can move. This arrangement enables the fork members 40 ',45' to be inserted under an object which is placed on an inclined surface without having to tip the entire Uft fork rack 1 to the same inclination as the surface. When the lift fork rack 1 with the fork members 40', 45' is lowered against the inclined surface, one of the fork members 40',45' will strike the surface before the other fork member 40',45' does. The fork 40',45' which first strikes the surface will be displaced relative to the coupling means 105' and thus also relative to the lift fork rack 1. When the lift fork rack 1 is lowered further, the other fork member 40',45' will strike the surface. Thereafter the lower- ing of the lift fork rack 1 will cease and the fork members 40',45' will be pushed in under the object to be lifted. Fig. 5 shows the fork members 40',45' in staggered position. Claims 1. Lift fork rack, comprising an upper beam (5), a lower beam (10) and at least two spacer elements (15, 20), which fix the upper and lower beams (5, 10) at a distance from and essentially parallel to each other, load-bearing fork members (40,45;40', 45') being mountable on the upper and lower beams (5, 10), said fork members (40,45;40',45') being displaceable along the length of the beams (5, 10), said spacer elements (15, 20) comprising attachment means (80,85) which are intended to releasably attach the lift fork rack (1) to a lift mechanism (75), characterized in that the upper beam (5) has a web (35) and a flange (25) which are joined to each other at an angle α differing from 90°; that the upper beam (5) is joined to each spacer element (15, 20) via the web (35); and that the web (35) is directed away from the lower beam (10). 2. Lift fork rack according to Claim 1, characterized in that the flange (25) extends transversely to its longitudinal direction substantially in a vertical plane and that the angle α between the web (35) and the flange (25) lies within the interval 40°- 50°. 3. Lift fork rack according to one of the preceding claims, characterized in that the web (35) of the upper beam (5) is inserted in a slot (55) which is arranged in each spacer element (15, 20). 4. Lift fork rack according to one of the preceding claims, characterized in that the flange (25) has a plurality of notches (120) along its length to determine the position of the fork members (40,45 ;40 ',45'). 5. Lift fork rack according to one of the preceding claims, characterized in that the lower beam (10) is a T-beam.

Claims: 7 6. Fork member intended to be mounted on a lift fork rack (1), comprising first and second legs (95, 100; 95', 100'), which form essentially a right angle to each other, said first leg (95 95') having coupling means (105; 105 ') for coupling together with a first and a second beam (5,10) of the Uft fork rack (1), said second leg (100,100') having a load surface (115) for carrying a load, characterized in that the first and second legs (95, 95'; 100,100') extend in separate planes. 7. Fork member according to Claim 6, characterized in that each fork member (40,45 ;40', 45') is displaceable laterally relative to the upper and lower beams (5, 10). 8. Fork member according to one of Claim 6 or 7, characterized in that each fork member (40',45') is displaceable relative to the coupling means (105') in the longi- tudinal direction of the first leg (95'). 9. Fork member according to Claim 8, characterized in that the coupling means (105') in the longitudinal direction of the first leg (95') has an elongated opening (125) in which a pin (130) on the first leg (95') can move. 1/5

Inventors: BACK DANIEL, LINDGREN GUNNAR, BACK, DANIEL, LINDGREN, GUNNAR
Applicants: BACK DANIEL, LINDGREN GUNNAR, VOLVO WHEEL LOADERS AB, BACK, DANIEL, LINDGREN, GUNNAR
Application year: 1997
Main classification: B66F9
IPC codes: B66F9