PREASSEMBLY UNIT FOR THE DRIVE OF AN INDUSTRIAL TRUCK

Abstract

A preassembly unit for the drive of an industrial truck, with a fifth wheel on which the driving wheel is rotatably mounted around a horizontal axis and which on its part is rotatably mounted in a bearing member around a vertical axis, a drive motor arranged on the fifth wheel, which is coupled with a driving shaft of the driving wheel via a gearbox, optionally a steering motor on the bearing member in order to turn the fifth wheel in the bearing member around the vertical axis, a parallel rod assembly between the bearing member and a frame of the industrial truck, which permits an essentially vertical movement of the preassembly unit in relation to the frame, and a spring arrangement between the bearing member and a frame-fixed section, wherein at least one upper drag rod of the parallel rod assembly is articulated on the lower end of a separate attachment section, which forms an interface with a counter-attachment position on the frame by attachment positions, and that at least one spring acts between a shoulder of the bearing member and an abutment of the attachment portion below the attachment positions.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention is explained in the following by means of an example of its realisation, depicted in drawings.

FIG. 1 shows a preassembly unit of the present invention in a low-lift industrial truck in a perspective view.

FIG. 2 shows the side view at the right side of the preassembly unit of FIG. 1.

FIG. 3 shows the front view of the preassembly unit of FIG. 2.

FIG. 4 shows the side view at the left side of the preassembly unit of FIG. 2.

FIG. 5 shows the top view on the preassembly unit of FIG. 2.

FIG. 6 shows the preassembly unit of FIGS. 2 to 4 in a perspective view.

DETAILED DESCRIPTION OF THE INVENTION

While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated

In FIG. 1, a low-lift industrial truck is partially depicted. It has a drive portion and a load portion. The drive portion is only represented with a frame 100 and a drive unit 10. The drive unit 10 will be described in more detail below by means of the FIGS. 2 to 6.

A load portion 102 has two parallel wheel arms 104, 106. Further, a battery accommodation can be recognised, which is fixedly connected to the wheel arms 104, 106. It will not be further dealt with the same. The part of the battery accommodation drawn upward, which is designated with 108, is connected with the lifting cylinder of the drive portion 10, as will be shown later.

A three-arm lever 110 is pivotally mounted on the load portion 102 around a horizontal axis at 112. On the opposing side, a corresponding lever is provided. One arm of the lever 110 is pivotally articulated on the flame 100 at 114. A third arm of the lever is articulated at 116 on a presser rod, which is lead inside the wheel arm 106. The same applies for the wheel arm 104. At the end of the wheel arms 104, 106, there are load wheels (not shown), which are mounted in a rocker which is connected with the respective presser rod. When the load portion 102 is lifted, the lever 110 pivots in the clock direction and by this it exerts a pressure on the presser rod. This kinematics is commonly known in low-lift industrial trucks.

In FIGS. 2 to 6, the drive unit 10 is depicted in more detail. In FIG. 1, the industrial truck is a three-wheel vehicle. It may be an usual handlebar- or drawbar-steered industrial truck, also with a four-wheel or five-wheel chassis.

A driving wheel 12 is rotatably mounted in a fifth wheel 14 around a horizontal axis. The fifth wheel 14 has an angle gearbox 16 and an upper horizontal toothed ring 18, on which a drive motor 20 is attached. The drive motor 20 may be a three-phase current motor or even a direct current motor, which brings the driving wheel 12 into rotation via the gearbox 16. The toothed ring 18 is rotatably mounted around a vertical axis in a bearing member 22. On the top side of the bearing member 22 sits upright a steering motor 24, which turns the fifth wheel 14 around the vertical axis when it is correspondingly triggered via a steering transmitter. The described components are conventional and therefore they have not to be discussed further in detail.

As results from the figures, the bearing member 22 has an upper horizontal section and a skirt 26 extending downward from the same in various degrees, which is partly formed in the shape of an arc of a circle. However, it is partly open on the rear side and there it forms a horizontal shoulder 28 below the disc 18. From the same, bearing lugs 30, 32 stand downward. They are approximately parallel and in a distance to each other. As becomes clear from the figures, relatively short drag rods are articulated on the beatings lugs 30, 32. On the bearing lug 30 a drag rod 34 is articulated, and on the bearing lug 32 a drag rod 36. The drag rod 36 is articulated on the outer side of the bearing lug 32, and the drag rod 34 on the inner side of the bearing lug 30. The articulation takes place via rotational necks in corresponding bores of the bearing lugs 30, 32, which are not shown in more detail. Only in FIGS. 2 and 6, a bearing neck can be recognised at 38.

The drag rods 34, 36 are welded together with a pipe 40. They form an entity with the pipe. Through the pipe, a bearing rod or -shaft 42 is guided through, which is attached on the frame 100 of the industrial truck (FIG. 1).

On the top side of the bearing member 22, an upper bearing lug 44 is attached on the rear side of the drive motor 20, which is arranged approximately in the centre between the lower bearing lugs 30, 32. On the bearing lug 44, one single upper drag rod 46 is articulated, which is articulated on a lower lug 48 of an attachment section 50 at its other end. Thus, the drag rods 34, 36 and 46, the bearing lugs 30, 32 and the attachment section 50 form a parallel rod assembly, which permits an approximately vertical movement of the drive unit 10.

The attachment section 50 has attachments flanges 54, 56 located in one plane on opposing sides of a shell of a lifting cylinder 52, formed in one piece therewith, each with two attachment bores for attachment on a wall section of the vehicle frame 100. On the piston rod of the lifting cylinder 52, a flange plate 58 is attached for connection with the load portion 102 of the industrial truck.

Below the flanges 54, 56, disc-shaped abutments 60, 62 for springs 64, 66 are arranged. The springs 64, 66 are supported at the lower end on a plate section of the shoulder 28.

In order to dismount the drive unit 10, it is only necessary to bring the bearing necks out of engagement with the bearing lugs 30, 32 through a small sideways movement of the drive unit 10. When the bearing rod 42 is pulled out of the pipe 40, the drive unit is free and it can be removed. Naturally, this functions only when the fastening of the flanges 54, 56 on the frame has been released before.

As results from FIG. 1 in particular, the lower drag rods 34, 36 on the frame 100 of the drive portion are mounted on the same axle as the one arm of the lever 110 for the lifting rod assembly. Thus, the construction expenditure is kept very low and the drive unit is realised compactly.

The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.

Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.

This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.

Claims

1. A preassembly unit for the drive of an industrial truck, with a fifth wheel on which the driving wheel is rotatably mounted around a horizontal axis and which on its part is rotatably mounted in a bearing member around a vertical axis, a drive motor arranged on the fifth wheel, which is coupled with a driving shaft of the driving wheel via a gearbox, optionally a steering motor on the bearing member in order to turn the fifth wheel in the bearing member around the vertical axis, a parallel rod assembly between the bearing member and a frame of the industrial truck, which permits an essentially vertical movement of the preassembly unit in relation to the frame, and a spring arrangement between the bearing member and a frame-fixed section, characterised in that at least one upper drag rod (46) of the parallel rod assembly is articulated on the lower end of a separate attachment section (50), which forms an interface with a counter-attachment position on the frame by attachment positions, and that at least one spring (64) acts between a shoulder (28) of the bearing member (22) and an abutment (60) of the attachment section (50) below the attachment positions.

2. A preassembly unit according to claim 1, characterised in that the industrial truck has a drive portion and a load portion and the attachment section (50) is formed in one piece with a cylinder shell of a lifting cylinder (52), the piston rod of which acts on the load portion (102) above the attachment section (50).

3. A preassembly unit according to claim 1, characterised in that the attachment section (50) has two flanges (54, 56) located in one plane, with attachment holes (57).

4. A preassembly unit according to claim 1, characterised in that it is realised with a drawbar.

5. A preassembly unit according to claim 1, characterised in that the attachment section (50) has a bearing lug pointing downward and the shoulder of the bearing member (22) has a bearing lug (44) pointing upward, for one single upper drag rod (46).

6. A preassembly unit according to claim 1, characterised in that two parallel spaced springs (64, 66) are provided.

7. A preassembly unit according to claim 1, characterised in that an abutment for a spring is provided below the flanges.

8. A preassembly unit according to claim 1, characterised in that the bearing member (22) has two parallel spaced downward standing bearing lugs (30, 32), the lower drag rods (34, 36) are fixedly connected to a hollow member which is arranged between the bearing lugs (30, 32) and through which a bearing shaft (40) is lead through, and the lower drag rods (34, 36) and the bearing lugs (30, 32) are arranged such that the member can be moved in a direction away from the bearing lugs (30, 32).

9. A preassembly unit according to claim 8, characterised in that the upper drag rod (46) is bearing mounted on the upper bearing lug (44) at the same side as the lower drag rod (36), bearing mounted on the outside on the facing bearing lug (32).

10. A preassembly unit according to claim 2, characterised in that lifting rod assemblies act on front load wheels of the load portion (102), which are each articulated on an arm of a lever (110), rotatably mounted on the load portion (102), and the axles of the lower drag rods (34, 36) and the articulation of the levers (110) on the frame (100) are coaxial.

11. A preassembly unit according to claim 7, characterised in that the lever's (110) are pivotally mounted on the bearing shaft (42).

12. A set of different preassembly units according to claim 1, characterised in that each one has the same attachment section (50) for mounting on an identical interface on the frame (100) of an industrial truck.