WO1999020484A1

WO1999020484A1 - A device for recovery of wheeled vehicles

Info

Publication number: WO1999020484A1
Application number: PCT/SE1998/001911
Authority: WO
Inventors: Christer Forsberg
Original assignee: Skantz-Nyhammars Bruk Ab
Priority date: 1997-10-22
Filing date: 1998-10-22
Publication date: 1999-04-29
Also published as: SE9703853D0; SE9703853L

Abstract

In a device for recovering wheeled vehicles there is an elongated element (1, 7) movably connected to the recovering vehicle for lifting the front part of a vehicle to be recovered for towing thereof. The elongated element has two members, namely a second (1) pivotably connected to the recovering vehicle about a second axis (3) and a first member (7) pivotably connected to the second member about a first axis in parallel with the second pivot axis and intended to be equipped with means for lifting front portions of a vehicle to be recovered. At least a second power means (9) is arranged to act between the recovering vehicle and the second member (1) and one first power means (10) to act between the second member (1) and the first member (7) for moving the first member (7) with respect to the recovering vehicle.

Description

A DEVICE FOR RECOVERY OF WHEELED VEHICLES

FI ELD OF THE INVENTION AND PRIOR ART

The present invention relates to a device for recovery of wheeled vehicles through lifting a front member and towing thereof, which comprises an elongated element pivotably connected to a rear end of a recovering vehicle about a first axis being substantially horizontal in the normal position of this vehicle and which may be equipped with a means for gripping under and lifting front portions of a vehicle to be recovered when the element is pivoted upwardly so as to keep the vehicle in this position through the elongated element during towing, and at least one power means adapted to act between the recovering vehicle and the elongated element so as to produce the pivoting of the elongated element about said axis.

Said rear end of the recovering vehicle is here to give a broad sense and has not necessarily to be constituted by the very chassis of a motor vehicle, but it could also be there for example on a trailer pulled by such a motor vehicle. A device of this type may be adapted to recover all types of wheeled vehicles, such as for example cars, lorries and buses.

A disadvantage of devices already known of this type is that said first pivot axis has to be located at a comparatively low height above the ground, which is achieved through suitable brackets secured to the chassis of the recovering vehicle and extending downwardly, so that the angle of the elongated element with respect to the horizontal plane will not be to great in the position when it is pivoted down to the ground, which position necessarily has to be assumed for loading of for example private cars with the wheels thereof received in said means, which then are arranged at the rear end of the elongated ele- ment. This means in its turn that a horizontal position of the elongated element is reached at a comparatively low height when pivoting it upwardly, which makes it impossible to lift and recover heavy vehicles by means of so-called "lifting forks", since such forks, which grip under frame parts of these vehicles, have to be directed substantially horizontally with the support surfaces thereof, which means that the elongated element has to be directed substantially horizontally, and these forks have at the same time to be lifted to a considerable height so as to lift the heavy vehicle sufficiently. Should the elongated element be pivoted beyond the horizontal position and by that the heavy vehicle be lifted with support surfaces of said lifting forks inclined and by that an inclination of these forks with respect to the vertical line, the heavy vehicle will then when the arrangement is turning in curves during towing fall from the device. Thus, al- ready known devices of this type may not meet both demands mentioned above at the same time, so that a conventional equipment may not be used for lifting heavy vehicles, but various special measures being time consuming and costly have to be taken.

Another disadvantage of the devices already known is that the lifting power, which may be applied on the elongated element, of course will be dependent upon the angle of the elongated element with respect to the recovering vehicle, so that the power means has to be over-dimensioned so as to have a sufficient lifting power in all positions. Furthermore, it gets complicated to arrange the elongated element so that it may be pivoted upwardly and point substantially in the vertical direction upwardly, which is desirable when the recovering vehicle is driven without any vehicle on the device. However, should the arrangements be so that the elongated element, which preferably is made of a beam with possibly prolongation pieces possibly telescopically arranged therein, could after all be pivoted substantially straight upwardly, the lifting power of said power means would be so low that the elongated element may not under any circumstances be utilised in so-called "high hoisting", which often is necessary in recovering situations.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a device of the type defined in the introduction, which to a large extent finds a remedy to the inconveniences discussed above of such devices already known.

This object is according to the invention obtained by providing the elongated element in such a device with two members, namely a second member pivotably connected to the recovering vehicle about a second axis in parallel with said first axis and a first member pivotably connected to the second member about said first axis and intended to be equipped with said means, and it comprises at least one second power means acting between the recovering vehicle and the second member and one first power means acting between the second member and the first member for pivoting said members about said axes.

By dividing the elongated element in this way in two members connected in series in this way while obtaining two pivot axes and the arrangement according to the invention of at least two power means several considerable advantages with respect to the devices already known are obtained. It is now possible to obtain a horizontal position often desired of the member equipped with said means for lifting in several different vertical positions, and the pivot axis at the recovering vehicle (the second pivot axis) may now be arranged at a considerable height and the elongated element may nevertheless be given a desired direction in a lower position for loading, so that it will be possi- ble to obtain a substantially horizontal direction of said first member at such a high level above the ground that it will be possible to recover heavy vehicles by means of so-called "lifting forks" by the device according to the invention. Furthermore, thanks to the arrangement according to the invention of the two power means it will be possible to ensure that these compliment each other when lifting, so that a substantially constant lifting force is obtained in all conceivable vertical positions of the elongated element. It will also be possible, starting from every horizontal position, to tilt the first member of the elongated element upwardly or downwardly through the first power means. It will also easily be possible to arrange the power means and said pivot axes so that said first member may be put substantially straight upwardly with substantially full power counteracting a pivoting downwardly thereof, which makes it possible to utilise the device in so-called "high hoisting".

According to a preferred embodiment of the invention the first and second power means are individually controllable for inde- pendent pivoting of the first member about the first axis and the second member about the second axis. It gets in this way possible to obtain almost arbitrary directions of said first member, which may be equipped with means for lifting, with respect to the ground in a various of different vertical positions of the front end of the first member, which is connected to the recovering vehicle through the second member. An optimum adaption of the device to the appearance, the weight and so on of the vehicle to be recovered may in this way be obtained.

According to another preferred embodiment of the invention the device comprises an arrangement adapted to control said power means according to movement patterns desired for said first member of the elongated element. It will by this by possible, which for the rest is a subject of an additional preferred em- bodiment of the invention, to control the first and second power means depending upon each other for maintaining a substan- tially constant direction of the first member with respect to the ground independently of the vertical position thereof by pivoting in opposite directions about the first and second axis, and an automatic horizontal alignment of the first member with respect to the ground could in this way easily be obtained for different vertical positions desired of this member.

According to another preferred embodiment of the invention the power means are of the type with variable length, and they are arranged so that a prolongation of the first power means causes a pivoting of the first member about the first axis in the opposite direction to a pivoting of the second member about the second axis caused by a prolongation of the second power means. By arranging the power means in this way they complement each other to an optimum for obtaining a substantially constant lifting force independently of the position of said first member of the elongated element.

According to another preferred embodiment of the invention the second member of the elongated element has the character of a link piece and is substantially shorter than the first member, which forms the real elongated element. An appropriate arrangement of the power means for obtaining a good lifting force in different positions of the first member is facilitated by such a design of the second member.

According to another preferred embodiment of the invention the second power means is adapted to affect the second member close to the first pivot axis which, as an additional embodiment of the invention, in which the first power means is adapted to affect the second member close to the second pivot axis and has its connection to the first member at the rear end thereof close to the first pivot axis, contributes to good power transferring characteristics in different positions of operation of the de- vice. Further advantages as well as advantageous features of the invention appear from the following description and the other dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a description of a preferred embodiment of the invention cited as an example.

In the drawings:

Fig 1 is a schematic side-elevation illustrating a device according to a preferred embodiment of the invention in a possible operating position,

Fig 2 is a side-elevation enlarged with respect to fig 1 of a part of the device in fig 1 ,

Fig 3 is a view from above of the part of the device shown in fig 2,

Fig 4 is a side-elevation illustrating the device in a second possible operating position,

Fig 5 is a side-elevation of the device in a third possible operating position, and

Fig 6 is a side-elevation of the device in a fourth possible operating position.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

The construction of a device according to a preferred embodiment of the invention will now firstly be explained while referring simultaneously to fig 1 -3. The device comprises a second member 1 having the character of a link piece, which is pivotably connected to the rear end of a vehicle 2 about a second pivot axis 3 being substantially horizontal in a normal position of the recovering vehicle 2 schematically indicated through a bracket 5 secured to the chassis 4 of the vehicle.

The vehicle 2 is preferably a so-called platform recovering vehicle, i.e. a vehicle intended to receive a platform or wagon-bridge for recovering a vehicle by lifting the entire vehicle onto the platform, and which accordingly may recover two vehicles simultaneously thanks to the device according to the invention.

The device has also a first member 7 pivotably connected to the end of the second member opposite to the pivot axis 3 about a first pivot axis 6 being substantially parallel to the second pivot axis, said first member having the character of an elongated element and which may preferably be prolonged to a desired length by adding pieces preferably telescopically introducable into each other, as the one 8 shown in fig 1 . The first and second member 7 replace the so-called elongated element of the devices of this type already known, in which the name of this within this technical field is "stick", and it is here primarily the first member 7 that may be considered to be such a stick.

The device has also two second power means 9 in the form of hydraulic cylinders connected in parallel with each other and acting between the recovering vehicle (through the bracket 5) and the second member 1 , which may have a length of stroke of for example about 350 mm. The points of affection of the second power means 9 are located substantially directly over the second pivot axis 3 on the bracket 5 and at one end of the second member 1 close to said first pivot axis 6, respectively. Thus, by shortening and prolongation of the power means 9 the second member 1 may be brought to pivot about the second pivot axis 3 and the position of the first pivot axis 6 may by that be moved along a circle arc path upwardly and downwardly.

Furthermore, the device has two first power means 10 in the form of hydraulic cylinders connected in parallel with each other, which are adapted to act between the second member and the first member for pivoting the first member with respect to the second member about said pivot axis 6. The two first power members 10 are in fig 3 hidden by the second power means 9. The points of affection or attack of the first power means on the second member 1 are located close to the second pivot axis 3, and the points of affection on the first member 7 are located at one end thereof close to the first pivot axis 6. Thus, by shortening and prolongation of the first power means 10 said first mem- ber 7 may be brought to pivot with respect to the second member 1 about the first pivot axis 6 for adjusting the direction of the first member 7 with respect to the ground in a fixed position of the axis 6.

The function of the device according to the invention should well appear from above, but it will now nevertheless be explained with reference to fig 4-6. It is illustrated in fig 4 how the first member 7 of the device may be at the free end thereof equipped with means 1 1 for receiving the front wheels 12 of a private car 13 to be recovered. It is of course also possible to arrange other such means on the first member 7, such as for example lifting forks described above for recovering heavy vehicles, and it is possible to alternate between different such means in one and the same device. The means 1 1 is in the present case consti- tuted by pieces having frames for receiving the respective vehicle and protruding from the member 7 at a substantially right angle. The vehicle 13 may then in the position shown in fig 4 be towed while resting on the ground through the rear wheels. When a vehicle is to be recovered by means of the device ac- cording to the invention the power means 9, 10 are preferably actuated so that the lower position shown in fig 6 with the first member 7 being substantially horizontally directed is obtained. For example a private car may in this position be pulled onto the means 1 1 , or at another type of lifting means, such as for recovering heavy vehicles, the first member 7 may be brought under the vehicle to be recovered by reversing. The first member 7 may then from the position according to fig 6 be lifted by actuating the power means 9, 10, in which this takes place while maintaining a horizontal direction thereof if so desired. The first and second power means 10 and 9, respectively, are in the lat- ter case shortened all the time, so that the pivoting experienced by the second member with respect to the second axis 3 is counteracted by a pivoting in the opposite direction of the first member 7 about the axis 6. The device is adapted to reach a highest possible position of the member 7 with a horizontal di- rection thereof, which substantially corresponds to the wagon- bridge height of the recovering vehicle and is obtained when both the power means 9 and the power means 10 are contracted to a maximum. This position corresponds to the position according to fig 5 with respect to the second member 1 , but the first power means 10 have with respect to the position according to fig 5 to be contracted completely so as to obtain a horizontal direction. Preferably, this corresponds to a height of about 900 mm, which is completely sufficient for lifting heavy vehicles by conventional lifting forks.

The device according to the invention according to the preferred embodiment manages a load of about 6 tons at the extremity 14 of the fist member and about 10 tons at the other end 15 of the first member.

The lifting force delivered by the power means 9, 10 during the lifting of a vehicle to be recovered will through the arrangement of these power means according to the invention be substantially constant, so that the power means have not to be over-di- mensioned for managing certain extreme positions with unfavourable angles of attack. It is also illustrated in fig 5 how the first member 7 may be pivoted substantially straight upwardly by prolonging the first power means 10, and this member is held with full power in this posi- tion, so that it may be utilised in so-called "high hoisting" for for example pulling vehicles stuck free.

The invention is of course not in any way restricted to the preferred embodiments described above, but many possibilities to modifications thereof would be apparent to a man skilled in the art without departing from the basic idea of the invention.

The device could for example have one single first and single second power means.

It would also be possible to arrange a greater number of prolongation pieces for forming the first member 7, or to completely refrain from such prolongation pieces.

Claims

1 . A device for recovery of wheeled vehicles through lifting a front member and towing thereof, which comprises an elon- gated element pivotably connected to a rear end of a recovering vehicle (2) about a first axis (6) being substantially horizontal in the normal position of this vehicle and which may be equipped with a means (1 1 ) for gripping under and lifting front portions of a vehicle (13) to be recovered when the element is pivoted upwardly so as to keep the vehicle in this position through the elongated element during towing, and at least one power means adapted to act between the recovering vehicle and the elongated element so as to produce the pivoting of the elongated element about said axis, char- acterized in that the elongated element comprises two members, namely a second member (1 ) pivotably connected to the recovering vehicle about a second axis (3) in parallel with said first axis and a first member (7) pivotably connected to the second member about said first axis and intended to be equipped with said means, and that it comprises at least one second power means (9) acting between the recovering vehicle and the second member and one first power means (10) acting between the second member and the first member for pivoting said members about said axes (3, 6).

2. A device according to claim 1 , characterized in that the first (10) and second (9) power means are individually controllable for independent pivoting of the first member about the first axis and the second member about the second axis.

3. A device according to claim 1 or 2, characterized in that it comprises an arrangement adapted to control said power means (9, 10) according to movement patterns desired for said first member (7) of the elongated element.

4. A device according to claim 3, characterized in that the control arrangement is adapted to control the first and second power means (9, 10) depending upon each other for maintaining a substantially constant direction with respect to the ground of the first member independently of the vertical position thereof by pivoting in opposite directions about the first and second axis.

5. A device according to claim 4, characterized in that said di- rection is substantially parallel to the ground when the recovering vehicle stands on a substantially horizontal ground.

6. A device according to any of claims 1 -5, characterized in that the power means (9, 10) are of the type with variable length, and that they are arranged so that a prolongation of the first power means (10) causes a pivoting of the first member (7) about the first axis (6) in the opposite direction to a pivoting of the second member (1 ) about the second axis (3) caused by a prolongation of the second power means (9).

7. A device according to claim 6, characterized in that the first power means (10) is adapted to pivot the rear end of the first member upwardly when prolonged, and the second power means (9) is adapted to pivot the rear end of the second member downwardly and by that the front end of the first member downwardly when prolonged, so that the second power means is adapted to determine the vertical position of the first axis (6) and the first power means is adapted to determine the inclination of the first member (7) in a certain vertical position of the first axis.

8. A device according to claim 6 or 7, characterized in that the first and second power means (9, 10) are, starting from a lower position with a substantially horizontal extension of the first member, adapted to both be shortened so as to both be shortened substantially to a maximum when a maximum lifted position with said first member directed substantially horizontally is reached.

9. A device according to claim 8, characterized in that the first member (7) is adapted to be located about 900 mm above the ground in said position lifted to a maximum.

10. A device according to any of claims 1 -9, characterized in that the second member (1 ) of the elongated element has the character of a link piece and is substantially shorter than the first member (7) forming the real elongated element.

1 1 . A device according to claim 10, characterized in that the length of the second member (1 ) is of the same order of magnitude as the length of said first and second power means (9, 10), which are of the type with a variable length.

12. A device according to any of claims 1 -1 1 , characterized in that the first and second power means (9, 10) is of the type with variable length and have substantially the same length of stroke.

13. A device according to any of claims 1 -12, characterized in that the power means (9, 10) are hydraulically driven.

14. A device according to any of claims 1 -13, characterized in that it comprises two first power means (10) connected in parallel and two second power means (9) connected in parallel.

15. A device according to any claims 1 -14, characterized in that the second power means (9) is adapted to affect the second member (1 ) close to the first pivot axis (6).

16. A device according to any of claims 1 -15, characterized in that the first power means (10) is adapted to affect the sec- ond member (1 ) close to the second pivot axis (3) and has its connection to the first member (7) at the rear end thereof close to the first pivot axis (6).

17. A device according to any claims 1 -16, characterized in that it is adapted to be arranged behind a space of a recovering vehicle (2) intended to receive a platform for recovering an additional vehicle through the recovering vehicle by lifting the entire vehicle onto the platform.