GB2436711A

GB2436711A - Industrial tractor with a coupling device

Info

Publication number: GB2436711A
Application number: GB0705700A
Authority: GB
Inventors: Jean-Marie Martin
Original assignee: Linde Material Handling GmbH; Linde Material Handling GmbH and Co KG
Current assignee: Linde Material Handling GmbH; Linde Material Handling GmbH and Co KG
Priority date: 2006-03-28
Filing date: 2007-03-26
Publication date: 2007-10-03
Anticipated expiration: 2027-03-26
Also published as: FR2899153B1; GB2436711B; DE102006014336A1; FR2899153A1; DE102006014336B4; GB0705700D0

Abstract

Industrial tractor for the transportation of mobile transport containers (12 Fig. 2), in particular roll containers or box pallets. The industrial tractor has a coupling device (8) for coupling a mobile transport container (12 Fig 2) to the industrial tractor. According to the invention, the coupling device (8) has a hook (9), which is open at the top and can be moved in the vertical direction in such a way that by raising the hook (9), a transport container (12 Fig 2) can be coupled to the industrial tractor. According to a development of the invention, the coupling device (8) has a safety element (10), which prevents an unintentional movement of the transport container (12 Fig 2) relative to the hook (9) in the upward direction. The safety element (10) can be formed by an inflatable airbag.

Description

1 2436711 * Industrial tractor with a coupling device The invention

relates to an industrial tractor for the transportation of mobile transport containers, in particular roll containers or box pallets, the industrial tracfor having a coupling device for coupling a mobile transport container fo the industrial tractor.

Industrial tractors of said type are especially designed for the transportation of mobile transport containers, such as are used, in particular, in the retail food trade and wholesale food trade. These transport containers generally have four wheels, a base plate and at least two side grid walls which project upwardly from the base plate. Two pivot rollers and two non-pivotable wheels are generally provided as wheels. If is also known to equip transport containers of this type with four pivot rollers. The goods to be transported are stacked on top of one another to a height of about 2 metres on the base plate between the side grid walls.

The mobile transport containers are frequently pushed manually by warehouse workers. However, there is a risk here of the transport container tipping over, above all in the case of goods which are heavy and piled up high.

This risk is particularly great during the manual pushing or pulling of the transport containers because the force introduction point is located at the level of the hands of the warehouse worker and therefore at the top of the transport container.

* Known industrial tractors are only suitable to a limited degree for the transportation of the above-described transport containers. These industrial tractors are frequently derived from drawbar-sleered lifting trucks and have a drive wheel which can be steered by means of a steering drawbar and two wheels, which are not driven, cannot be steered and are not pivotable. The coupling device in known industrial tractors is designed similarly to a coupling known from the lorry or passenger car sector and, to a limited degree, allows a rotary movement of the transport container relative to the industrial tractor in all directions. This is necessary in known industrial tractors in order to produce the steerability of the system consisting of the industrial tractor and transport container.

However, the risk exists of lateral bending of the transport container relative to the industrial tractor, for example, in the case of a laterally inclined road or when the transport container is pushed. Moreover, the coupling devices of known industrial tractors prove unpractical with respect to handling.

The present invention is based on the object of providing an industrial tractor with a coupling device, which is easy to handle and ensures a reliable connection between the industrial tractor and transport container.

This object is achieved according to the invention in that the coupling device has a hook, which is open at the fop and is moveable in the vertical direction in such a way that by raising the hook a transport container can be coupled to the industrial tractor. In this case, the hook hooks into a defined component of the transport container. The component may expediently be a horizontal strut, which is arranged in the region of a base plate, on the transport container. In the open position of the coupling device, the hook is located completely below said component of the transport container. To couple the transport container, the industrial tractor is positioned in such a way that the hook is located below the component. The hook is then raised, so it hooks in the component of the transport container. The coupling device is therefore closed.

According to an expedient configuration, the hook is biased upwardly by means of a spring. The force exerted upwardly on the hook is defined, in this case, by the spring. The spring is designed, in this case, such that the transport container is not raised by the force of the hook.

To allow the coupling device to be opened, the hook can be moved downwardly by means of an actuator against the force of the spring. The actuator may be designed, for example, as an electrically driven threaded spindle, as a hydraulic cylinder or as a pneumatic cylinder.

The actuator is particularly advantageously designed as a pneumatic actuator. Pneumatic actuators are available economically and, in contrast to hydraulic actuators, there is no risk of soiling the road by escaping pressure medium.

According to a particularly advantageous development of the invention, the coupling device has a safety element, which prevents an unintentional movement of the transport container relative to the hook in the upward direction. The safety element prevents the component of the transport means picked up by the hook from jumping up out of the hook. The safety element is activated precisely when the hook is located in the raised position and the coupling device is therefore closed.

A limited relative movement of the transport container relative to the industrial tractor can be made possible in that the safety element is formed by a flexible component.

According to a possible embodiment, the flexible component is formed by an inflatable airbag. The airbag consists of a flexible material and can be filled with compressed air, so it increases its volume.

The airbag is arranged in such a way that the airbag in the inflated state is located at least partially over the hook which is open at the top. In this case, the airbag closes the opening of the hook in such a way that a component of the transport container picked up in the hook is held in the hook.

The coupling device is designed in such a way here that a transport container coupled to the industrial tractor is fixed with respect to a rotation about a vertical axis relative to the industrial tractor. This means that a rotation

I

of the transport container about a vertical axis is only possible together with the industrial tractor. The transport container bending away when the industrial tractor is in coasting mode or with a laterally inclined road is reliably prevented thereby.

Driving onto ramps with an upwardly or downwardly inclined road is made possible in that the coupling device is designed in such a way that a transport container coupled to the industrial tractor can be pivoted about a horizontal transverse axis of the industrial tractor relative to the industrial tractor.

The subject of the invention is also a transport system with an industrial tractor with the above-described features, the transport container having a horizontally extending profiled strut, into which the hook of the coupling device can be hooked. The profiled strut on the transport container is used, for example, as a support for a base of the transport container and is also used for coupling to the industrial tractor.

Further advantages and details of the invention are described in more detail with the aid of the embodiment shown in the schematic figures, in which: Figure 1 shows an industrial tractor according to the invention in a side view; Figure 2 shows a plan view of an industrial tractor with a coupled transport container; Figure 3 shows a coupling device in the opened state; and Figure 4 shows a coupling device in the closed state.

Figure 1 shows an industrial tractor according to the invention in a side view. A frame 1 of the industrial tractor, on which a drive unit 2 with a drive wheel 3 is mounted in a steerable manner, can be seen. The required steering force is exerted on the drive unit 2 by an operator by means of a drdwbar 4.

Located at the end of the industrial tractor opposing the drive unit 2 is a total of four non-driven wheels. These are two wheels 6 which cannot be pivoted

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relative to the frame 1 and two wheels 7 pivotably mounted on the frame 1, which are designed as pivot rollers. Mounted on the load end of the industrial tractor is a coupling device 8. which comprises a hook 9 which can be moved in the vertical direction. A horizontal strut of a mobile transport container can be hooked into from below with the hook 9. The coupling device 8 also comprises a safety element 10, which prevents the horizontal strut of the transport container from jumping up out of the hook 9. The safety element 10 is configured as an inflatable airbag, which, in the inflated slate, arches to the right in the drawing over the hook 9. The various units of the industrial tractor, for example electric drive batteries, an electrically driven compressor and a power electronics unit to supply the compressor and the drive unit 2 are located under a housing 11.

Depending on the operating situation of the industrial tractor, in particular depending on whether a transport container 12 is coupled to the industrial tractor, the non-pivotable wheels 6 are raised or are in contact with the road.

For this purpose, the non-pivotable wheels 6 are height-adjustably mounted on the frame 1. When the hook 9 is lowered and therefore the coupling device 8 is open, the non-pivot able wheels 6 are lowered. If, on the other hand, the hook 9 is raised and therefore the coupling device 8 is closed, the non-pivotable wheels 6 are raised. The pivotable wheels 7 arranged on the outside are in contact with the road in every situation. When, with the coupling device 8 closed, both the pivotable wheels 7 and the non-pivotable wheels 6 are in contact with the road, the non-pivotable wheels 6 are used for track guidance of the industrial tractor and the pivotable wheels 7 prevent lateral tipping over of the industrial tractor.

Figure 2 shows a plan view of an industrial tractor with a coupled transport container 12. The industrial tractor and the transport container 12 together form a transport system. The transport container 12 is rigidly coupled to the industrial tractor. The coupling device 8, in particular, prevents rotation of the transport container 12 relative to the industrial tractor about an axis which is perpendicular onto the plane of the drawing. With the transport container 12 coupled, the industrial tractor stands with the pivofable wheels 7 on the road.

The turning radius of the transport system is then determined by the arrangement of the wheels on the transport container 12. When the wheels 13 adjacent to the industrial tractor are not pivotable and the wheels 14 spaced apart from the industrial tractor are pivotable, the turning radius Ri is produced.

On the other hand, the turning radius R2 is produced when the wheels 13 of the transport container 12 adjacent to the industrial tractor are pivofable and the wheels 14, which are spaced apart from the industrial tractor, are not pivotable.

Figure 3 and Figure 4 show a coupling device 8 according to the invention. In the view according to Figure 3, the coupling device is in the opened state. Also shown is the component 31, formed by a horizontal profile, of a transport container (Figure 2, pos. 12) in which the hook 9 can engage.

One of the wheels 32 of the transport container is also shown.

In the opened position of the coupling device 8 according to Figure 3, the hook 9 is located clearly below the component 31. In this case, the hook 9 is pressed downward against the force of a spring 33 by a pneumatic actuator 34, a pneumatic cylinder here. The transport container 12 is freely moveable. A safety element 10 is located inside a housing lOa. If the coupling device 8 is now closed, the hook 9 is raised and the safety element 10 is activated at the same time.

The closed position of the coupling device is shown in Figure 4. It can be seen here how the hook 9 is hooked in the component 31 of the transport container. The force of the spring 33 is such that the transport container is not raised. The safety element 10 formed by an inflatable airbag archesover the component 31 and presses it against the hook 9. As a result, the component 31 in the hook has no play at all, so rotation of the transport container 12 relative to the industrial tractor about a vertical axis is prevented. The component 31 jumping out in the upward direction is also prevented, as the inflated safety element 10 is located partly over the component 31. This arrangement allows a slight rotation between the industrial tractor and transport means about a horizontal axis which is perpendicular to the plane of the drawing, the safety element 10 being slightly deformed.

Claims

Claims 1. An industrial tractor for the transportation of mobile

transport containers, in particular roll containers or box pallets, wherein the industrial tractor has a coupling device for coupling a mobile transport container to the industrial tractor, characterised in that the coupling device has a hook, which is open at the top and can be moved in the vertical direction in such a way that, by raising the hook, a transport container can be coupled to the industrial tractor.

2. An industrial tractor according to claim 1, characterised in that the hook can be upwardly biased by means of a spring.

3. An industrial tractor according to claim 2, characterised in that the hook can be moved downwardly against the force of the spring by means of an actuator.

4. An industrial tractor according to claim 3, characterjsed in that the actuator is designed as a pneumatic actuator.

5. An industrial tractor according to any one of claims 1 to 4, characterised in that the coupling device has a safety element, which prevents an unintentional movement of the transport container in the upward direction relative to the hook.

6. An industrial tractor according to claim 5. characterised in that the safety element is formed by a flexible component.

7. An industrial tractor according to claim 6. characterised in that the flexible component is formed by an inflatable airbag.

8. An industrial tractor according to claim 7, characterised in that the airbag is arranged in such a way that the airbag, in the inflated state, is located at least partially over the hook which is open at the fop.

9. An indusfrial tractor according to any one of claims 1 to 8, characferised in that the coupling device is designed in such a way that a transport container coupled to the industrial tractor is fixed with regard to a rotation about a vertical axis relative to the industrial tractor.

10. An industrial tractor according to any one of claims 1 to 9, characterised in that the coupling device is designed in such a way that a transport container coupled to the industrial tractor can be pivoted about a horizontal transverse axis of the industrial tractor relative to the industrial tractor.

11. Transport system with an industrial tractor according to any one of claims 1 to 10 and a mobile transport container, characterised in that the transport container has a horizontally extending profiled strut, info which the hook of the coupling device can be hooked.