WO2008147218A2

WO2008147218A2 - Forklift truck and method for transporting a forklift truck

Info

Publication number: WO2008147218A2
Application number: PCT/NO2008/000193
Authority: WO
Inventors: Olav Lauvdal
Original assignee: Olav Lauvdal
Priority date: 2007-05-30
Filing date: 2008-05-30
Publication date: 2008-12-04
Also published as: WO2008147218A3

Abstract

Forklift (3) comprising - a body (2) with a front side, a left side, a right side and a rear side, the rear side having a lower edge; - a mast (4) which is provided with movable forks (5), the mast being arranged at the front side of the body,- - front wheels and a rear wheel (7) provided in the body close to the front side of the body and the rear side of the body respectively; - protective means enabling the forklift to function as an underrun protector when the forklift is attached to the rear side of a truck or a trailer of a truck (1).

Description

FORKLIFT TRUCK AND METHOD FOR TRANSPORTING A FORKLIFT TRUCK

The present invention relates to a forklift and a method for transporting a forklift attached to the rear of a truck or the trailer of a truck such that the forklift satisfies official requirements for underrun protection. For a truck and the truck's trailer the are government regulations that require that there is a maximum vertical height from the ground and up to the lower rear and side edges of the truck and the trailer. This maximum underrun height may differ from county to country - in for example Norway, the maximum height is 40cm at present. If the height from ground up to the lower edge of the truck or the trailer is more than the allowed maximum height, an underrun protector must be attached to the truck and/or the trailer. The reason for these regulations is that in the case that the truck slows down quickly or the truck is involved in an accident, other cars should not get in under the truck or the trailer.

Often it is desirable to carry a forklift together with a truck for quick and easy unloading and/or loading of transported goods or goods to be transported. In order not to take up space in the truck that is better used for the transportation of goods, the forklift can be attached to the rear side of the truck or the trailer of the truck by using the forks of the forklift.

The problem is that the requirements to the maximum vertical height from the ground and up to the lower rear edge of the truck, which means the rear side of the forklift when it is attached to the truck, still applies. The problem is that the rear wheel or wheels extends down lower than the rear edge of the forklift such that if the rear edge of the forklift is raised to the maximum height allowed (for instance 40 cm in Norway), the distance from the ground up to the wheel may be just 20 cm or less. When taking into account that the distance from the rear wheels of the truck to its rear side may be more that 240cm and adding the length of the forklift, which is attached to the rear side of the truck, the distance from the rear wheels of the truck to the rear wheel of the forklift may be 350cm. That means that the rear wheel of the forklift will very easily hit the ground when the truck passes just a small bump in the road. If the forklift is raised higher up, the requirements to the maximum height allowed between the ground and the lower egde of the rear side of the truck will not be met.

The objective of the present invention is therefore to provide a forklift and a method for transporting a forklift from one place to another where the forklift, which is mounted at the rear part of a truck or a trailer of the truck, can function as the required underrun protector. It is also an objective of the invention that the attaching and detaching of the forklift should be easy and quick for the user. These objectives are achieved with the invention as defined in the attached independent claims. Further embodiments of the invention are defined in the dependent claims.

There is provided a forklift comprising: - a body with a front side, a left side, a right side and a rear side, the rear side having a lower edge; a mast which is provided with movable forks, the mast being arranged at the front side of the body;

- front wheels and a rear wheel provided in the body close to the front side of the body and the rear side of the body respectively;

- protective means enabling the forklift to function as an underrun protector when the forklift is attached to the rear side of a truck or a trailer of a truck.

The mast of the forklift is preferably tiltable, which is normal for forklifts. The forklift may also have two rear wheels in stead of one. Throughout the description and claims only a rear wheel is mentioned. It should, however, be understood that forklifts which are provided with two rear wheels are included.

In an embodiment of the invention, the protective means comprises a height adjustable rear wheel and locking means for locking the wheel in at least one lower position and at least one upper position. Preferably the underside of the body of the forklift comprises a cavity into which the rear wheel at least partly can be placed in its upper position.

One way to achieve this is to mount the rear wheel to a lower end of a support column. The support column and the rear wheel can be raised and lowered in a substantially vertical direction between the at least one lower position and at least one upper position. In order to raise and lower the support column, it may be connected to a hydraulic system for the raising and lowering of the support column and the rear wheel. The support column itself can be part of a cylinder/piston arrangement or external cylinder/piston arrangements can be connected to the support column for raising and lowering the support column and the rear wheel. It would also be possible to arrange the support column such that the raising and lowering of the support column and the wheel is done manually by an operator. Another option would be to use the weight of the forklift and let it sink down on the rear wheel and locking the rear wheel in that position. The lowering of the support column and the wheel would the preferably be carried out using the gravitational force acting on the support column and the rear wheel and possibly with some help from the operator.

Another way to raise and lower the rear wheel is to mount the rear wheel to a support column, where the support column can be rotatably connected to the body of the forklift. When the support column is rotated, the vertical position of the rear wheel is raised or lowered between the at least one lower and one upper position. As for the embodiment above, the rotation of the support column may be effected by a hydraulic system or an operator may rotate the support column manually.

The locking means may comprise a bolt that fixes the support column and the rear wheel in the desired upper or lower position. Alternatively, the locking means may comprise a hydraulic system that fixes the support column and the rear wheel in the desired upper or lower position. This would preferably be the same hydraulic system that effects the raising and lowering of the support column between its upper position and its lower position. Obviously, it would also be possible to use a combination of the two locking means to lock the support column and the rear wheel in its positions.

There is also a requirement to the length of the underrun protection as compared to the breadth of the truck. If the breadth of the forklift is not sufficient to satisfy this requirement, the protective means may comprise at least one side cross bar mounted to a rear part of the body of the forklift such that, in a transport position, the at least one cross bar extends in a sideways direction to the left or to the right. The side cross bar will then, at least in part, can function as an underrun protector. The at least one side cross bar and the lower edge of the forklift will form the underrun protector and together the will have a length that fulfills the official requirements. Since the forklift, for stability reasons, preferably are mounted to the truck or the trailer more or less in the middle between the left and the right side of the truck or the trailer, the forklift will normally be provided with a side cross bar on each side of the forklift. The cross side bars may be mounted to the rear side of the forklift or directly below the lower edge of the rear side of the body of the forklift. In another embodiment of the invention, the protective means comprises a frame, the frame comprising two bars and a cross bar connected to two ends of the side bars while the other two ends of the bars are connected to the body of the forklift such that the frame is movable between an upper position and a lower position in which the cross bar can function as an underrun protector. The shape of the frame will be similar to the Greek letter pi (FI) where the crossbar may extend slightly beyond the connection where it is joined to the two bars in order to meet the requirement to the length of the underrun protector.

The bars are preferably rotatably connected to the left side and the right side of the body such that the cross bar can be rotated between an upper position and a lower position in which the cross bar can function as an underrun protector. The frame can be raised and lowered between the lower position and the upper position by using a hydraulic system or by lifting and lowering the frame manually. An alternative would be to connect the two bars to the rear part of the body of the forklift such that frame is movable in a substantially vertical direction between an upper position and a lower position in which the cross bar can function as an underrun protector. The two bars could be slideably connected to guides mounted to the rear side of the body of the forklift or the two bars could be placed into correspondingly shaped openings in the underside of the rear part of the body of the forklift. The two bars would then move up and down inside the openings in the body itself when the frame is raised or lowered between the lower and upper positions. Again, the raising and lowering of the frame may be effected by a hydraulic system or manually by an operator.

If the crossbar extends beyond the connections joining the crossbar and the two bars, then the end sections of the crossbar extending beyond the connection joining the bars and the cross bar, may be arranged movably between a retracted position and an extended position. This can be done by arranging the two end sections telescopically into the middle part of the crossbar or attaching the end sections hingedly to the middle of the cross bar or the connection between the cross bar and the two bars.

Furthermore, the forklift preferably comprises means for locking the frame in an upper position and in a lower position in which the cross bar can function as an underrun protector. As before this may be done with a hydraulic system, particularly if the frame is arranged so that the raising and lowering of the frame between the lower position and the upper position is effected with a hydraulic system. Optionally, the locking of the frame in the upper and lower position may be effected with a bolt. A combination of the two may also be used if that is desirable. An alternative embodiment for an underrun protector would be a single cross bar having the required length and being arranged such that it can be attached to attaching means on provided to the rear part of the body of the forklift. When the forklift is being prepared for transport, the single crossbar is attached and secured to the attachment means and before the forklift is being used to carry loads, the single crossbar is removed. The attachment means on the body of the forklift may be a number of pins, bolts or any other suitable attachment means. The locking means could be bolts or similar means.

It is also possible to form the frame in two parts such that there are two cross bars that function as underrun protection together with the rear wheel. One frame with its cross bar on each side of the rear wheel. The two frames may be rotatably connected to the body of the forklift between a working position for the forklift and a position where the crossbars of the frames and the rear wheel together forms an underrun protector. The two frames may also be connected to the body of the forklift such that the two frames can be lowered and raised in a substantially vertical direction between an upper position and a lower position where the crossbars of the frames and the rear wheel together forms an underrun protector. For both alternatives a hydraulic system may be employed for moving the frames between its different positions. Similarly, f there are two rear wheels on the forklift one can imagine using three frames, each with a crossbar that, together with the two rear wheels, can function as an underrun protector. One frame should be arranged on the outside of each rear wheel and one frame should be arranged between the two rear wheels.

There is also provided a method for making a forklift as described above, ready for transport, wherein the forklift comprises a body with a front side, a left side, a right side and a rear side, the rear side having a lower edge; - a mast which is provided with forks, the mast being arranged at the front side of the body; - front wheels and a rear wheel kan vcere flere enn ett provided in the body close to the front side of the body and the rear side of the body respectively; protective means enabling the forklift to function as an underrun protector when the forklift is attached to the rear side of a truck or a trailer of a truck; and wherein the method comprises the following steps: - positioning the forks so that they can be entered into corresponding fork holders arranged on the rear side of the truck or the trailer of the truck; enter the forks into the fork holders by moving the forklift forward on the ground; raising the forklift off the ground by using the forks of the forklift; and - arranging the protective means such that the forklift can function as an underrun protector.

It should be mentioned that in the description the forklift is referred to having a rear wheel. This should be understood such that the forklift also can be provided with two rear wheels. A further step of the method according to the invention is to secure the forks in the fork holders, either before raising the forklift from the ground or after the forklift has been raised from the ground. This can be done with one or more bolts or any other suitable means for securing the forks of the forklift in the fork holders.

The method also comprises the step of adjusting the vertical height of the rear wheel from a lower position to a upper position in the vertical direction and locking the rear wheel in the higher position. The lower position can be regarded as the working position of the rear wheel, while the upper position may be regarded as the transportation position of the rear wheel. The locking of the wheel in its upper position may be effected by a hydraulic system, manually or by using a combination of the two locking methods as described above.

The method also comprises the step of extending the side cross bar or side cross bars such that the underrun protector, formed by the has the required length. In an alternative embodiment of the method, the frame, comprising two bars mounted to the left and right sides of the body, and a crossbar connected to the end of the bars, is lowered to the lower position such that the cross bar can function as a underrun protector. The frame is preferably locked in its lower position before the transportation of the forklift starts. In an embodiment of the method, the ends of the cross bar are extended such that the crossbar gets the required length to function as an underrun protector.

According to the invention, there is also provided a use of a forklift as an underrun protector on a truck or a trailer of a truck, the forklift being attached to the rear side of the truck or the trailer of the truck. In the following, a few embodiments of the invention will be described with reference to the drawings, which all show the invention in schematic way, where

Figure 1 shows side view of truck with forklift attached. Figure 2 shows a rear view of an embodiment. Figure 3 shows a top view of an embodiment with a frame. Figure 4 shows a side view of the embodiment in figure 3.

Figure 5 shows a side view of another embodiment with a frame. Figure 6 shows a rear view of the embodiment in figure 5.

Figure 1 shows the forklift 3 mounted to a truck 1 comprising a body 2. As can be seen from the figure, the forks 5, attached to the mast 4 of the body 2, are held by the fork holders 6 which are mounted on the truck 1. The distance h indicated on the figure is the distance to which there in many countries are requirements of a maximum distance. In order to be able to meet the requirement when transporting a forklift at the rear side of a truck, it will be necessary to provide a underrun protector. In the embodiment shown on figure 2 shows that the lower edge of the rear side of the forklift 3 is used as an underrun protector by lifting the rear wheel 7 and thereby allowing the forklift to assume a lower position without the rear wheel 7 bumping into the ground 14 when the truck is moving. In order to meet the requirement of the length/breadth of the underrun protector, side cross bars 8 are provided. The side cross bars 8 may be telescopically or hingedly attached to the rear part of the body 2 of the fork lift. The height 15 now satisfy the requirement to the maximum height.

In figures 3 and 4 a different embodiment of the invention is shown where the forklift is provided with a rotatable frame 10. The frame 10 comprises bars 11 connected to a crossbar 12 in connections 9. The frame can be raised and lowered between an upper and a lower position as indicated on figure 4. The frame can be locked in both positions with suitable locking means (not shown). In its lower position, the frame 10 satisfies the requirement to a maximum height 15 for underrun protection. The crossbar 12 is shown provided with end sections 13 in order to meet the requirement to length/breadth of the underrun protector.

In figures 5 and 6 shows a slightly different version of the frame 10 where the frame is mounted to the underside of body 2 (could also be mounted at the rear side of the body) such that the frame 10 moves up and down between an upper position and a lower position. The frame 10 is lockable in both positions by using suitable locking means (not shown). Again the height 15 satisfies the requirement to maximum height. The crossbar 12 is also shown with end sections 13 to ensure that the crossbar meets the length requirement.

Reference numbers: 1. truck

2. body of forklift

3. forklift

4. mast

5. forks 6. fork holder

7. rear wheel of forklift

8. side cross bar

9. connection joining the middle section of the cross bar and end section

10. frame 11. bar

12. cross bar

13. end sections

14. ground

15. maximum height between the ground and the lowest part of the rear part of the forklift.

Claims

1. Forklift comprising a body with a front side, a left side, a right side and a rear side, the rear side having a lower edge; - a mast which is provided with movable forks, the mast being arranged at the front side of the body;

- front wheels and a rear provided in the body close to the front side of the body and the rear side of the body respectively; characterized in that - the forklift is provided with protective means enabling the forklift to function as an underrun protector when the forklift is attached to the rear side of a truck or a trailer of a truck.

2. Forklift according to claim 1, characterized in that the protective means comprises a height adjustable rear wheel and locking means for locking the wheel in at least one lower position and at least one upper position.

3. Forklift according to claim 2, characterized in that the rear wheel is mounted to a lower end of a support column, and that the support column and the rear wheel can be raised and lowered in a substantially vertical direction between the at least one lower position and at least one upper position.

4. Forklift according to claim 3, characterized in that the support column is connected to a hydraulic system for the raising and lowering of the support column and the rear wheel.

5. Forklift according to claim 2, characterized in that the rear wheel is mounted to a support column, the support column being rotatably connected to the body whereby the vertical position of the rear wheel can be raised or lowered between the at least one lower and one upper position by rotating the support column.

6. Forklift according to one of the claims 2-5, characterized in that the locking means comprises a bolt that fixes the support column and the rear wheel in the desired upper or lower position.

7. Forklift according to one of the claims 2-5, characterized in that the locking means comprises a hydraulic system that fixes the support column and the rear wheel in the desired upper or lower position.

8. Forklift according to one of the claims 1-7, characterized in that the protective means comprises at least one side cross bar mounted to a rear part of the body of the forklift such that, in a transport position, the at least one cross bar extends in a sideways direction whereby the side cross bar, at least in part, can function as an underrun protector.

9. Forklift according to claim 1, characterized in that the protective means comprises a frame comprising two bars and a cross bar connected to two ends of the side bars while the other two ends of the bars are connected to the body of the forklift such that the frame is movable between an upper position and a lower position in which the cross bar can function as an underrun protector.

10. Forklift according to claim 9, characterized in that the bars are rotatably connected to the left side and the right side of the body such that the cross bar can be rotated between an upper position and a lower position in which the cross bar can function as an underrun protector.

11. Forklift according to claim 9, characterized in that the bars are connected to the rear part of the body of the forklift such that frame is movable in a substantially vertical direction between an upper position and a lower position in which the cross bar can function as an underrun protector.

12. Forklift according to claim 1, characterized in that the ends of the cross bar extending from the connection joining the bars and the cross bar, is movable between a retracted position and an extended position.

13. Forklift according to one of the claims 9-12, characterized in that the forklift comprises means for locking the frame in an upper position and in a lower postion in which the cross bar can function as an underrun protector.

14. Method for making a forklift, according to one of the claims 1-13, ready for transport, the forklift comprising - a body with a front side, a left side, a right side and a rear side, the rear side having a lower edge; a mast which is provided with forks, the mast being arranged at the front side of the body; front wheels and a rear wheel provided in the body close to the front side of the body and the rear side of the body respectively; protective means enabling the forklift to function as an underrun protector when the forklift is attached to the rear side of a truck or a trailer of a truck; characterized in that the method comprises the following steps:

- positioning the forks so that they can be entered into corresponding fork holders arranged on the rear side of the truck or the trailer of the truck;

- enter the forks into the fork holders; raising the forklift off the ground by using the forks of the forklift; and - arranging the protective means such that the forklift can function as an underrun protector.

15. Method according to claim 14, wherein the forks are secured in the fork holders.

16. Method according to one of the claims 14-15, wherein the vertical height of the rear wheel is adjusted from a lower, working position to a higher, transport position and locked in the higher position.

17. Method according to claim 16, wherein the side cross bar or side cross bars are extended such that the underrun protector, formed by the side cross bar or bars and the lower edge of the rear side of the body of the forklift, has the required length.

18. Method according to claim 14, wherein the frame, comprising two bars mounted to the left and right sides of the body, and a crossbar connected to the end of the bars, is lowered to the lower position such that the cross bar can function as a underrun protector.

19. Method according to claim 18, wherein frame is locked in its lower position.

20. Method according to claim 18-19, wherein the ends of the cross bar are extended such that the crossbar gets the required length to function as an underrun protector.

21. Use of a forklift as an underrun protector on a truck or a trailer of a truck, the forklift being attached to the rear side of the truck or the trailer of the truck.