GB2206329A

GB2206329A - Roll-over jacks

Info

Publication number: GB2206329A
Application number: GB08814332A
Authority: GB
Inventors: Edward Albert Peedell
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-18
Filing date: 1988-06-16
Publication date: 1989-01-05
Also published as: GB8714277D0; GB8814332D0

Abstract

A roll-over jack for vehicles is actuated by an hydraulic ram 11 that comprises a cylinder 12 which is mounted on the free end 10 of a pivoted lifting arm 8, and a piston within the cylinder 12, which is pivotally coupled via a hollow piston-rod 14 to the triangular base 1 of the jack. The cylinder 12 is pivoted to a bracket 13 on the end 10 of the arm 8 to extend upwardly therefrom away from the working area beneath the arm 8. Hydraulic fluid supplied to the cylinder 12 via the hollow rod 14 from an hydraulic power pack 17 on the base 1, causes the arm 8 to rise from the base 1 about its pivot at the apex-end 7 and it may be locked there by aligning and locking together two pivotable struts (26-28). A rod 21, which may be fitted with extension tubes 24 and 25, lies horizontally and transversely of the base 1 at the apex-end 7 to provide an abutment for wheels of the vehicle and arrest tendency of the vehicle to slip sideways from the jack. <IMAGE>

Description

Jacks This invention relates to jacks.

The invention is in particular, though not exclusively, concerned with jacks of the kind known as roll-over jacks, in which a pivoted arm for carrying the load to be lifted, turns about its pivot, to incline the load, in the jacking action. Such jacks are used for example for gaining access to the underparts of a motor car or other vehicle, where the use of more sophisticated and expensive lifting gear is precluded or not justified; this may be the case where, for example, the underside of the vehicle is to be cleaned or coated with a sealant against corrosion, and adequate access can be obtained by rolling the vehicle over slightly.

It is one of the objects of the present invention to provide a form of jack that is readily applicable as a roll-over jack and offers economy of construction and simplicity of operation.

According to the present invention there is provided a jack having a lifting arm that is pivoted towards one of its ends to a base of the jack, and means that is actuable to exert jacking force to incline the arm upwardly from the arm about the pivot, wherein the actuable means is carried on the arm remotely from the said one end to exert the jacking force between the arm and the base.

The said actuable means may be an hydraulic ram comprising a piston acting within a cylinder, and in this case the cylinder of the ram may be mounted on the arm towards the end remote from the pivot and extend upwardly from the lifting arm. The piston may have a rod that extends to the base and is coupled to the base such that actuation of the ram causes the lifting arm to pivot upwardly from the base. The base of the jack, which may be in the general form of a triangular- or Aframe structure, may carry an hydraulic unit for control of supply of hydraulic fluid to the cylinder.

The base of the jack may be mounted on castors so as to enable the jack as a whole to be readily manoeuvred.

Furthermore, the jack may be equipped with one or more arresting arms that project outwardly from the base substantially parallel to the pivot axis of the lifting arm, for use in restraining movement between the jack and the load being lifted, during jack operation. In this latter respect, two arresting arms may be provided, one projecting in one horizontal direction, and the other in the opposite horizontal direction, from the base, and in this case the two arms may be formed by a rod or bar mounted on the base adjacent the lifting-arm pivot with its ends projecting in opposite directions from the base, and two extension tubes or other members that couple to respective ends of the rod or bar, in line with it.

A roll-over jack in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side perspective view of the jack with its lifting arm lowered; and Figures 2 and 3 are perspective views of the jack from opposite ends, showing the jack with the lifting arm lowered and raised, respectively.

Referring to the drawings, the jack has a horizontal, rigid base 1 of a generally elongate triangular- or Aframe structure, that stands clear of the ground on four castors 2 to 5. The castors 2 and 3 at the wideend 6 of the base 1 are free to swivel for manoeuvring the jack, whereas the castors 4 and 5 located towards the apex-end 7 of the base 1, are fixed to run in the lengthwise direction of the jack.

The lifting arm 8 of the jack is pivoted at one end 9 to the apex-end 7 of the base 1. From the end 9, the arm 8 extends lengthwise of the base 1 with its other, free end 10 located adjacent the base wide-end 6. An hydraulic ram 11 is carried at the free end 10 of the arm 8, this comprising a cylinder 12 mounted directly on a bracket 13 which is fixed to the arm 8 at the end 10, and a piston (not shown) within the cylinder 12 and coupled through a hollow piston-rod 14 to the base 1.

More especially, the piston-rod 14 is pivoted to a bracket 15 which is carried by a cross-member 16 of the base 1 at the wide-end 6, and the cylinder 12 is pivotally-mounted on the bracket 13 to project upwardly from the arm 8 at substantially a right angle to it.

An electrically-operated hydraulic power pack 17 is mounted on the base 1 at the wide-end 6 and is coupled by a pipe 18 to regulate supply of hydraulic fluid under pressure to the cylinder 12 via the hollow piston-rod 14. In this respect, the pack 17, as well as incorporating a reservoir for hydraulic fluid, contains (not shown) an hydraulic pump and a control unit for regulating supply and release of fluid to and from the cylinder 12 of the ram 11. An electrical motor assembly 19 for driving the pump is included with the pack 17, and in addition to an electric motor incorporates an electrical solenoid for controlling energisation of the motor from an external (or internal) electrical supply source (not shown).

Operation of the control unit to actuate the ram 11, whether by supplying or releasing fluid to, or from, the cylinder 12, is effected from a manually-actuable control 20 of the pack 17. When the control 20 is operated to supply fluid to the cylinder 12, the cylinder 12 is driven upwardly on the piston-rod 14 and thereby lifts the end 10 of the lifting arm 8, inclining it upwardly about the pivot at the apex-end 7 of the base 1. Operation of the control 20 to release fluid from the cylinder 12, allows the arm 8 to fall under its own weight out of the inclined position.

A rod 21 is fixed at its mid-point to the apex-end 7 of the base 1 for use in restraining tendency for relative movement between the jack and the load lifted by the arm 8. The rod 21 extends horizontally and transversely of the base 1 adjacent and substantially parallel to the pivot axis of the lifting arm 8, with its ends 22 and 23 projecting in opposite directions from the base 1. Two tubes 24 and 25 (shown in Figure 3 only) may be slid onto the ends 22 and 23 respectively of the rod 21, to extend the rod 21, in line, in both directions.

The roll-over jack may be used to roll a vehicle, such as a motor van or passenger car, through an angle up to some forty-five degrees (in the manner illustrated in broken line in Figure 3), in order, for example, to enable access to be gained to the underside of the vehicle for cleaning and/or undersealing. The jack is initially inserted from one side of the vehicle, apexend 7 first, to extend transversely under the vehicle about mid-way between the vehicle's front and back wheels, with the cylinder 12 projecting perpendicularly upwards from the end 10 of the arm 8, spaced from the vehicle side. The jack is inserted to such an extent that the rod 21 lies just beyond the line of the front and back wheels on the far side of the vehicle, so as to enable the extension tubes 24 and 25 to be slid onto the ends 22 and 23 of the rod 21. It is then pulled back slightly to bring the tubes 24 and 25 against the outsides of those wheels.

A source of electrical supply, which may be the battery of the vehicle to be lifted, is now connected to the motor assembly 19 of the power pack 17, ready for actuation of the jack. In this respect, operation of the control 20 to supply fluid to the ram 11 causes the arm 8 to lift up into contact with the underside of the vehicle and then to roll the vehicle about the two wheels on its far side, as the inclination of the arm 8 is increased. Abutment of the extension tubes 24 and 25 with those wheels arrests tendency of the vehicle to slip sideways as the inclination increases and the other two wheels leave the ground.

Once the desired inclination has been reached, release of the control 20 stops supply of fluid to the ram 11, and lifting is halted. Although the pack 17 maintains the established fluid pressure in the cylinder 12, so as to hold the arm 8 still, it is desirable for safety purposes that the arm 8 be locked mechanically in position before any work is carried out under the vehicle. To this end, a simple lock mechanism can be provided on the jack, and may, for example and as illustrated in broken line in Figure 3 alone, involve a pair (or possibly a plurality of such pairs) of rigid links 26 and 27 which are pivoted together and, respectively, to the arm 8 and the base 1.A tube or collar 28 threaded on the links 26 and 27 of the pair may be used to lock their interconnecting pivot joint, and thereby the appropriately-raised arm 8, simply by locating the tube or collar 28 securely over that joint. Subsequent release of the tube or collar 28 from the pivot joint frees the arm 8 for movement again, so that operation of the control 20 then enables the arm 8 to be raised further, or lowered, as desired.

The jack described is simply constructed. For example, the base 1 and arm 8 may be fabricated of welded mildsteel channel-section, with the section of the arm 8 at the end 10 lying between, and mounted by a pivot pin to, two sections forming the sides of the triangular frame where these come in towards one another at the apex-end 7.

Although the ram 11 may have a telescopic piston-rod to achieve the length of stroke required, this is generally not necessary, since a stroke of one metre or more, may be readily achieved otherwise.

The form of jack described, in which the ram 11 is mounted on the lifting arm 8, and the cylinder 12 project upwardly from that arm 8, has especial advantage. In particular, it has the advantage that the ram 11 is away from the working area under the lifting arm 8, leaving that area clear, and is not subjected to dirt, grease and fluids that may fall from the lifted vehicle.

Claims

Claims:

1. A jack having a lifting arm that is pivoted towards one of its ends to a base of the jack, and means that is actuable to exert jacking force to incline the arm upwardly from the arm about the pivot, wherein the actuable means is carried on the arm remotely from the said one end to exert the jacking force between the arm and the base.

2. A jack according to Claim 1 wherein the said actuable means is an hydraulic ram comprising a piston acting within a cylinder.

3. A jack according to Claim 2 wherein the cylinder of the ram is mounted on the arm towards the end remote from the pivot, and the piston has a rod that extends to the base and is coupled to the base such that actuation of the ram causes the lifting arm to pivot upwardly from the base.

4. A jack according to Claim 3 wherein the base of the jack carries an hydraulic unit for controlling supply of hydraulic fluid to the cylinder.

5. A jack according to any one of Claims 2 to 4 wherein the cylinder is pivoted to the lifting arm.

6. A jack according to any one of Claims 2 to 5 wherein the cylinder extends upwardly from the lifting arm.

7. A jack according to any one of Claims 1 to 6 wherein the base of the jack is in the general form of a triangular- or A-frame structure with the lifting arm pivoted to an apex of the frame.

8. A jack according to any one of Claims 1 to 7 wherein the base of the jack is mounted on castors so as to enable the jack as a whole to be readily manoeuvred.

9. A jack according to any one of Claims 1 to 8 including one or more arresting arms that project outwardly from the base substantially parallel to the pivot axis of the lifting arm, for use in restraining movement between the jack and the load being lifted, during jack operation.

10. A jack according to Claim 9 wherein there are two arresting arms, one projecting in one horizontal direction, and the other in the opposite horizontal direction, from the base.

11. A jack according to Claim 10 wherein the two arms are formed by a rod or bar mounted on the base adjacent the lifting-arm pivot with its ends projecting in opposite directions from the base, and two extension tubes or other members that couple to respective ends of the rod or bar, in line with it.

12. A jack substantially as hereinbefore described with reference to the accompanying drawings.