GB1566537A - Transport truck - Google Patents

Abstract

This transport truck is provided with a load carrier (2) which can be lifted and lowered relative to a vehicle chassis (1). The load carrier (2) has two fork arms (10) with front running rollers (11). These running rollers (11) are each connected via a plunger (12, 13) to an articulation device in such a way that they can be swung up and down. The articulation device is attached between the chassis (1) and the load carrier (2) and comprises an articulated lever (16) whose ends (18, 22) are mounted in an articulated manner on the chassis (1) and the load carrier (2) respectively. A horizontal beam (17) is pivotably connected to the articulated lever (16) about a vertical axis (24). The ends of the plungers (12, 13) opposite the running rollers (11) are each fastened in an articulated manner to one side of the horizontal beam (17). The articulation device consists of few individual parts and it can be adapted in a simple manner to transport trucks of a different track gauge. <IMAGE>

Description

(54) TRANSPORT TRUCK (71) We, SIG SCHWEIZERISCHE INDUSTRIE-GESELLSCHAFT, a Swiss body corporate, of 8212 Neuhausen Am Rheinfall, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a transport truck having a load carrier which can be raised and lowered relative to a vehicle chassis. A transport truck of this kind is known from Swiss Patent No. 443,930. In this transport truck there Is provided a joint device between the chassis and the load carrier to ensure that the rear support and driving wheels, as well as the front tread rollers, always remain in contact with the ground.

This joint device is, however disadvantageous in some respects. Its design is costly as it comprises many individual parts and the kinematics are complicated so that production and assembly is rendered very expensive.

Moreover the joint device cannot be adapted in a simple manner to transport trucks of a different track width as such an adaptation implies an alteration of the chassis. This is a great disadvantage as it is thus not possible to undertake alterations in accordance with the mechanical assembly technique. The object of the invention is thus to eliminate the aforementioned disadvantages.

In accordance with this invention there is provided a transport truck comprising a load carrier, which can be raised and lowered relative to a chassis of the truck and which has two fork arms provided with tread rollers, and a joint device connected by way of push rods to the tread rollers for raising and lowering said rollers relative to the tork arms, said joint device comprising a hinged link hinged to the chassis and to the load carrier so as to be pivotable m a substantially vertical plane. and a balance beam which is connected to the tinged link and which is pivotable m a substantialls horizontal plane, the ends of the balance beam being articulated with, and bearing against, the push rods associated with the tread rollers.

In contrast to the known trucks the transport truck in accordance with the invention is adaptable to trucks of different track widths, is relatively uncomplicated and hence cheaper to produce.

The invention will be further described hereinafter with reference to the accompanying drawing in which there is illustrated a perspective view of a truck embodying the invention.

The transport truck in the figure comprises a chassis 1 and a load carrier 2 which can be raised and lowered relative to the chassis. Two hydraulic cylinders 3 are provided for this purpose and are supported on two projecting support arms 4 of the chassis 1. Their pistons 5 act on a transverse beam 6 of the load carrier 2.

A steerable driving wheel 7 and a non-driven support wheel 8 are disposed in the chassis 1. A motive power battery 9 and the control and motor units (which are not shown), are also accommodated in the chassis.

The load carrier 2 has two fork arms 10 in each of whose front ends a tread roller 11 is mounted so as to be able to be swivelled up and down. The swivelling motion of the tread rollers 11 is caused by the to and fro movement of two push rods 12, 13 which are accommodated on the fork arms and act on associated rocking levers 14. The rocking levers 14 are mounted in the fork arms 10 by means of bearing pins 15 and each carry one of the tread rollers 11.

In order to equalise uneven portions of the ground, a joint device is provided between the chassis 1 and the load carrier 2 which has a hinged link to and a balance beam 17 which is rotatable about a vertical axle 24 and connected to the hinged link.

the one end X of the hinged link lf engages In a fusel heating block 19 which is welded ontt the t chassis 1 whereby the bearing pm 2() ot he bearing hlock iC) is seated in a guide slot of the hinged link end 18.

The other end 22 of the hinged link 16 is connected in an articulated manner to the load carrier 2 by means of a further bearing pin 23 and a second bearing block 26 welded onto the load carrier.

The ends of the push rods 12, 13 which are remote from the tread rollers 11 are each attached on one side of the balance beam 17 by means of ball-and-socket joints (25) and can be pivoted about the vertical axle 24 of the toggle joint 16. This vertical axle 24 is located somewhat medially in the toggle joint 16 and the balance beam 17.

When the load carrier 2 is raised by means of the hydraulic cylinders 3 the two cam followers 12, 13 are pressed forwards by the joint device where they cause the tread rollers 11 to swivel downwards. The hinged link 16 thereby describes a curved movement in its vertical plane determined by the two joints. Now in the case of uneven ground as soon as one tread roller, for example, has lifted itself up somewhat and pushes back its associated push rod 12 against the balance beam, the latter is swivelled about its vertical axle 24. The other push rod 13 is thereby moved forwards in the opposite direction in order to swivel the other tread roller downwards.

It is possible by means of the present transport truck to traverse uneven ground without any one of the wheels lifting off the ground. The complete- adhesion of the driving wheel is thus always ensured. The danger of high heavy loads tipping over is also largely eliminated as the fork arms are always kept horizontal.

The joint device is of a simple design and the kinematics are advantageously designed.

The adaptation of the joint device to transport trucks of different track widths is very simple as only the balance beam has to be altered. It is thus possible to adapt the joint device at once to the purpose for which it is to be used using mechanical assembly techniques, which in the case of other transport trucks was hitherto not possible.

WHAT WE CLAIM IS: 1. A transport truck comprising a load carrier, which can be raised and lowered relative to a chassis of the truck and which has two fork arms provided with tread rollers, and a joint device connected by way of push rods to the tread rollers for raising and lowering said rollers relative to the fork arms, said joint device comprising a hinged link hinged to the chassis and to the load carrier so as to be pivotable in a substantially vertical plane, and a balance beam which is connected to the hinged link and which is pivotable in a substantially horizontal plane, the ends of the balance beam being articulated with, and bearing against, the push rods associated with the tread rollers.

2. A transport truck as claimed in claim 1 in which said hinge mounted on the chassis is a bearing block disposed on the chassis, its bearing pin engaging in a guide slot which is provided in the end of the link.

3. A transport truck as claimed in claims 1 or 2 in which the balance beam, connected to the link, is disposed substantially medially on the link.

4. A transport truck as claimed in any of the preceding claims in which ball-andsocket joints are provided connecting the push rods to the ends of the balance beam.

5. A transport truck substantially as hereinbefore particularly described with reference to, and as illustrated in, the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. seated in a guide slot of the hinged link end 18. The other end 22 of the hinged link 16 is connected in an articulated manner to the load carrier 2 by means of a further bearing pin 23 and a second bearing block 26 welded onto the load carrier. The ends of the push rods 12, 13 which are remote from the tread rollers 11 are each attached on one side of the balance beam 17 by means of ball-and-socket joints (25) and can be pivoted about the vertical axle 24 of the toggle joint 16. This vertical axle 24 is located somewhat medially in the toggle joint 16 and the balance beam 17. When the load carrier 2 is raised by means of the hydraulic cylinders 3 the two cam followers 12, 13 are pressed forwards by the joint device where they cause the tread rollers 11 to swivel downwards. The hinged link 16 thereby describes a curved movement in its vertical plane determined by the two joints. Now in the case of uneven ground as soon as one tread roller, for example, has lifted itself up somewhat and pushes back its associated push rod 12 against the balance beam, the latter is swivelled about its vertical axle 24. The other push rod 13 is thereby moved forwards in the opposite direction in order to swivel the other tread roller downwards. It is possible by means of the present transport truck to traverse uneven ground without any one of the wheels lifting off the ground. The complete- adhesion of the driving wheel is thus always ensured. The danger of high heavy loads tipping over is also largely eliminated as the fork arms are always kept horizontal. The joint device is of a simple design and the kinematics are advantageously designed. The adaptation of the joint device to transport trucks of different track widths is very simple as only the balance beam has to be altered. It is thus possible to adapt the joint device at once to the purpose for which it is to be used using mechanical assembly techniques, which in the case of other transport trucks was hitherto not possible. WHAT WE CLAIM IS:

1. A transport truck comprising a load carrier, which can be raised and lowered relative to a chassis of the truck and which has two fork arms provided with tread rollers, and a joint device connected by way of push rods to the tread rollers for raising and lowering said rollers relative to the fork arms, said joint device comprising a hinged link hinged to the chassis and to the load carrier so as to be pivotable in a substantially vertical plane, and a balance beam which is connected to the hinged link and which is pivotable in a substantially horizontal plane, the ends of the balance beam being articulated with, and bearing against, the push rods associated with the tread rollers.

2. A transport truck as claimed in claim 1 in which said hinge mounted on the chassis is a bearing block disposed on the chassis, its bearing pin engaging in a guide slot which is provided in the end of the link.

3. A transport truck as claimed in claims 1 or 2 in which the balance beam, connected to the link, is disposed substantially medially on the link.

4. A transport truck as claimed in any of the preceding claims in which ball-andsocket joints are provided connecting the push rods to the ends of the balance beam.

5. A transport truck substantially as hereinbefore particularly described with reference to, and as illustrated in, the accompanying drawing.