GB2326868A

GB2326868A - Industrial masted lift truck

Info

Publication number: GB2326868A
Application number: GB9714025A
Authority: GB
Inventors: Paul John Eckersley
Original assignee: Lansing Linde Ltd
Current assignee: Linde Material Handling UK Ltd
Priority date: 1997-07-02
Filing date: 1997-07-02
Publication date: 1999-01-06
Also published as: DE19828937A1; GB9714025D0

Description

2326868 1 INDUSTRIAL TRUCK The invention concerns an industrial truck, for

example a reach truck, with a lifting framework which is tiltable relative to a frame of the industrial truck and which is displaceable relative to the frame in, a substantially horizontal reaching direction.

Industrial trucks are known in which the lifting framework is connected to a sliding carriage on which at least two rollers are disposed, the rollers being spaced, in the reaching direction. The rollers are movably guided in the reaching direction on the frame of the industrial truck.

Industrial trucks of the above described type, in which the lifting framework is displaceable relative to the frame of the industrial truck, are often additionally equipped with a device for tilting the lifting framework. In this case it is known for the lifting framework to be pivotably mounted about a horizontal pivot axis on the sliding carriage. This pivotable connection of the lifting framework to the sliding carriage involves significant construction costs and reduces the rigidity of the connection of the lifting framework to the frame of the industrial truck.

The object of the present invention is to provide an industrial truck in which tilting of the lifting framework is achieved at reduced cost while permitting a high degree of rigidity of the lifting framework. Ideally, the tilting arrangement also occupies less space than known arrangements.

According to the invention there is provided an industrial truck incorporating a lifting framework which is tiltable relative to a frame of the industrial truck and is displaceable relative to the frame in a substantially horizontal reaching direction, the lifting framework being connected to a sliding carriage on which at least two rollers are disposed, the rollers being spaced in the reaching direction and being movably guided in the reaching direction on the frame of the industrial truck, wherein the sliding carriage is moveable relative to at least one roller in a direction which includes a vertical component.

. 1 1 f 2 Thus in the industrial truck according to the invention, the rollers allow displacement of the lifting framework in the horizontal direction. Additionally, when the position of the at least one roller is altered relative to the sliding carriage, the sliding carriage - and hence the lifting framework - is tilted relative to the frame of the industrial truck. With this arrangement there is no need for the lifting framework to be mounted on the sliding carriage in a manner which enables relative movement because the tilting movement for the lifting framework is produced in the region of the rollers of the sliding carriage. This leads to reduced construction costs and, at the same time, increased rigidity of the industrial truck.

The lifting framework may be rigidly connected rigidly to the sliding carriage. In this case, both the number of force-transmitting components and the number of moveable connections between components are reduced.

In one embodiment of the invention at least one of the rollers is mounted on a beam axle which is pivotably mounted about a pivot axis on the sliding carriage. In this case, the beam axle can be rotated relative to the sliding carriage. Rotation of the beam axle moves the roller relative to the sliding carriage in a circular direction which incorporates a vertical component by means of which the sliding carriage and thus the lifting framework are tilted.

The pivot axis of the beam axle may be substantially parallel to the axis of rotation of the roller mounted on the beam axle, the pivot axis and the axis of rotation being spaced from one another.

The sliding carriage may incorporate a turning device for turning the beam axle about its pivot axis. The turning device determines the degree of tilting of the lifting framework and provides the force required for tilting the lifting framework.

The turning device may comprise a linear actuating unit, preferably an hydraulic cylinder.

The linear actuating unit may be attached at one end thereof to the sliding carriage and at the other end thereof to the beam axle. The linear actuating unit produces a linear movement which results in a turning movement of the beam axle.

1 3 Four rollers may be disposed on the sliding carriage, two rollers being disposed coaxial with one another on the sliding carriage and two rollers being disposed coaxial with one another on the beam axle. This arrangement corresponds to the usual arrangement with reach trucks with regard to the physical position of the rollers..; For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 is a diagrammatic side elevational view of one embodiment of an industrial truck according to the present invention; Figure 2 is a diagrammatic side elevation of a sliding carriage forming part of the industrial truck of Figure 1; and Figure 3 is a diagrammatic perspective view of the sliding carriage shown in Figure 2.

Figure 1 shows an industrial truck in the form of a reach truck. With industrial trucks of this type a lifting framework 1 is movably guided in a substantially horizontal reaching direction 3 on a frame 2 of the industrial truck. A load fork 4 is mounted on the lifting framework 1 in a manner so as to be moveable upwardly and downwardly on the lifting framework. A driving position 5 is also provided on the frame 2.

The lower end of the lifting framework 1 is rigidly connected to a sliding carriage 6. Four rollers 7, 8, which are displaceably guided in the frame 2 of the industrial truck, are provided on the sliding carriage. According to the invention the rollers 7 are moveable relative to the sliding carriage 6 in a direction which includes a vertical component. Considered in a spatially fixed reference system, this allows the sliding carriage to be tilted since the rollers 8 are fixed to the frame 2 in a manner which does not permit movement in a vertical direction.

In Figure 2 the sliding carriage 6 is shown in a side view opposite to the side view of Figure 1. The sliding carriage 6 can be seen with its rollers 7, 8 guided in the frame 2. As can be seen from Figure 2, the rollers 7 are mounted on a beam axle 9, the beam axle being pivotably mounted about a pivot axis 10 on the sliding carriage 6 The turning movement of the beam axle 9 is produced by means of a linear actuating unit in the form of an hydraulic cylinder 11. The hydraulic cylinder is attached at one end thereof to the beam of the axle 4 intermediate the ends of the beam and is attached at the other end thereof to the sliding carriage 6.

The arrangement of the beam axle is such that the axis of rotation of the rollers 7 is spaced from the pivot axis 10 in the reaching direction 3, while the beam of the beam axle 9 is offset from the pivot axis in a generally upward direction.

Thus, when the piston 11a of the hydraulic cylinder 11 is extended, the axle beam 9 turns clockwise (in Figure 2) about the pivot axis 10, that is in a direction which includes a vertical component, as a result of which the lifting framework is tilted forwards in the direction of the arrow 12. In the same way, retraction of the piston 11 a causes the lifting framework 1 to tilt backwards in the direction of the arrow 13.

The tilting axis of the lifting framework 1 and of the sliding carriage 6 is determined by the point of contact 14 of each of the front rollers 8 on the frame 2. At least one auxiliary roller 16 is disposed on the beam axle 9 to eliminate play in the rear rollers 7 which would otherwise arise within the frame 2. To permit rotational movement of the beam axle 9 the rotational axis of the auxiliary roller 16 lies on an arc 15 about the axis 10, the rotational axis of the rollers 7 also lying on the arc 15.

Figure 3 shows the sliding carriage 6 of Figure 2 in a perspective view. In particular, the design of the beam axle 9 and the arrangement of the hydraulic cylinder 11 can be seen in Figure 3.

1

Claims

1. An industrial truck incorporating a lifting framework which is tiltable relative to a frame of the industrial truck and is displaceable relative to the frame in a substantially horizontal reaching direction, the lifting framework being connected to a sliding carriage on which at least two rollers are disposed, the rollers being spaced in the reaching direction and being movably guided in the reaching direction on the frame of the industrial truck, wherein the sliding carriage is moveable relative to at least one roller in a direction which includes a vertical component.

2. An industrial truck according to claim 1, wherein the lifting framework is rigidly connected to the sliding carriage.

3. An industrial truck according to claim 1 or 2, wherein at least one of the rollers is mounted on a beam axle which is pivotably mounted about a pivot axis on the sliding carriage.

4. An industrial truck according to claim 3, wherein the pivot axis of the beam axle is substantially parallel to the axis of rotation of the roller mounted on the axle beam, the pivot axis and the axis of rotation of the roller being spaced from one another.

5. An industrial truck according to claim 3 or 4, wherein the sliding carriage incorporates a turning device for turning the beam axle about its pivot axis.

6. An industrial truck according to claim 5, wherein the turning device comprises a linear actuating unit.

7. An industrial truck according to claim 6, wherein the linear actuating unit comprises an hydraulic cylinder.

8. An industrial truck according to claim 6 or 7, wherein the linear actuating unit is attached at one end thereof to the sliding carriage and at the other end thereof to the beam axle.

9. An industrial truck according to any one of claims 3 to 8, wherein four rollers are disposed on the sliding carriage, two rollers being disposed coaxial with one another on the sliding carriage and two rollers being disposed coaxial with one another on the beam axle.

10. An industrial truck substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.