AU701019B2

AU701019B2 - Vehicle jack and stand

Info

Publication number: AU701019B2
Application number: AU71744/96A
Authority: AU
Inventors: Douglas G. Story
Original assignee: HILLAND Pty Ltd TRADING AS EDM
Current assignee: HILLAND Pty Ltd TRADING AS EDMO EQUIPMENT
Priority date: 1995-11-14
Filing date: 1996-11-13
Publication date: 1999-01-21
Anticipated expiration: 2016-11-13
Also published as: AU7174496A

Description

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1 TITLE: VEHICLE JACK AND STAND BACKGROUND OF THE INVENTION Field of the Invention THIS INVENTION relates to a vehicle jack and stand.

Prior Art The Industrial Standard AS/NZS 2643-1993 states that a person must not get under a vehicle supported on a vehicle jack, but that a vehicle must be supported by a suitable support stand.

Australian Standard AS 2538-1985 specifies the requirements for suitable vehicle support stands.

With more and more emphasis on Quality Assurance and on workplace health and safety, the provision of suitable vehicle jacks and vehicle support stands is a necessity in the, eg. transport and mining industries.

15 In most cases, vehicles are provided with sufficient specified jacking points so that to change a tyre, a jack can be provided at one jacking point and a support stand provided at a second °I jacking point to support the vehicle while the wheel is removed and replaced.

20 However, in certain instances, the jacking points are too close together to enable separate jacks and support stands to be used, or there are insufficient jacking points to enable both a jack and a o°°oo °stand to be used simultaneously.

SUMMARY OF THE PRESENT INVENTION 25 It is an object of the present invention to provide a unit which can operate both as a jack and as a stand.

It is a preferred object of the present invention to provide a unit where the locking mechanism for the stand can be remotely operated.

Other preferred objects of the present invention will become apparent from the following description.

In a broad aspect, the present invention resides in a vehicle jack and stand including: a base, optionally mounted on wheels; a jack cylinder on the base; and a jack piston, having a head, telescopically mounted in the cylinder and extensible therefrom, the head being engageable with a vehicle to lift the vehicle; wherein: a support stand tube, connected to the piston (and/or the head) coaxially surrounds the jack cylinder; and locking means on the tube are co-operable with complementary means on the cylinder to releasably lock the tube to the cylinder at at least one level of extension of the jack.

Preferably, the base, mounted on wheels, is provided with a handle to enable the jack and stand to be wheeled under a specified jacking point without the operator being positioned below the vehicle.

Preferably, remote operating controls are provided at the distal end of the handle.

Preferably, hydraulic fluid is selectively introduced into 20 the cylinder to cause the piston, and the tube, to be selectively S"extended to lift the vehicle.

Preferably, the locking means includes locking rings or :fingers selectively extendible inwardly towards the cylinder for releasable engagement with the complementary means on the cylinder.

25 Preferably, the complementary means include peripheral grooves about the wall of the jack cylinder, or teeth, preferably with substantially horizontal or undercut upper abutment faces for releasable engagement with the locking rings or teeth.

Preferably, the locking rings are mounted on guide pins received in slots on cam rings, to selectively move the locking rings into, and out of, engagement with the grooves or teeth on the wall of the jack cylinder.

Preferably, the cam rings are operable by a hydraulic or pneumatic cylinder remotely controlled by the operator.

In an alternative embodiment, the hydraulic cylinder and piston may be substituted by a mechanical jack, eg. of the screw type, where the support cylinder is connected to the head of the jack screw.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred embodiment will now be described with reference to the accompanying drawings, in which: FIG. 1 is a sectional side view of the jack and stand; FIG. 2 is a plan view of the locking mechanism; FIG. 3 is an enlarged view of the detail at A on FIG. 1; 15 and FIG. 4 is a sectional view taken on line B-B on FIG. 3.

~DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the jack and stand 10 has a base 11 mounted on transport wheels 100 and provided with a handle 101 to 20 enable the jack and stand 10 to be wheeled under a specified jacking point on a vehicle.

A jack cylinder 12 is mounted on the base and is provided with a jack piston 13, having a releasable head 14 secured by a cap screw 14a. Seal assemblies 15, 16 provide a sliding seal between the 25 piston 13 and the inner face 17 of the cylinder 12. Hydraulic fluid, under pressure, is introduced into the cylinder 12 via a hydraulic fitting 18, the flow of hydraulic fluid being controlled by a control valve (on a control unit 102) on the handle.

A stand support tube 20 is connected to the head 14 on the jack piston 13 and is provided coaxially around the jack cylinder 12. A locking mechanism 21, to be hereinafter described in more detail, with reference to FIGS. 2-4, is provided at the lower end of the support tube A plurality of circumferential grooves 22 are provided around the outer face of the jack cylinder 12 and each groove has a lower, horizontal abutment face 23. (If preferred, the faces 23 may be undercut, eg. in the range of 1 A peripheral flange 24 is provided at the lower end of the stand support tube 20 and supports three locking rings 25 arranged to be moved inwardly into (releasable) locking engagement with the abutment faces 23 in the circumferential grooves 22 on the jack cylinder 12.

Each locking ring 25 has a head 26 in which is engaged the shanks of a pair of guide pins 27. Each guide pin 27 is received in a respective slot 28 in a cam ring 29, which is selectively rotated by a hydraulic or pneumatic ram 30, remotely controlled from the control unit 102 on the handle 101.

Adjacent ends of the locking rings 25 are supported by a T-section extension 31 extending below the flange 24.

The operation of the jack and stand 10 will now be 20 described.

The operator wheels the jack and stand 10, using the handle 101, below the specified jacking point on the vehicle.

By operating the control valve in the control unit 102, high pressure hydraulic fluid is introduced to the hydraulic cylinder 12 25 to cause the piston rod 13 to be telescopically extended, moving the ~head 14 and the support tube 20 upwardly until the head 14 engages the jacking point.

Further extension of the piston 13 will raise the vehicle, eg. to enable a wheel to be changed.

The hydraulic or pneumatic ram 30 is retracted to rotate the cam ring 29 in a clockwise direction (see FIG. 2) so that the guide pins 27 are moved substantially radially inwardly to cause the locking rings 25 to enter a circumferential groove 22 on the jack cylinder.

If preferred, the jack piston 13 may be lowered until the locking rings 25 engage the abutment face 23 of the circumferential groove 22 into which all the locking rings 25 extend.

If the hydraulics of the jack should fail, the engagement of the locking rings 25 with the abutment face 23 on the jack cylinder 12 will prevent the jack piston 13, and head 14, being retracted and so the unit acts as a vehicle stand.

When the vehicle is to be lowered, the hydraulic or pneumatic ram 30 is extended to rotate the cam rings 29 counterclockwise (as shown in FIG. 2) to cause the locking rings 20 to be retracted from the circumferential groove 22 and the jack piston 13 can then be retracted into the cylinder 12 to enable the vehicle to be 15 lowered. The piston 13 may be raised slightly before the locking rings ~20 are retracted to reduce the loading on the rings 20. As the °°°operation of the jack piston 13 and the ram 30 for the locking rings °can be controlled remotely, the unit complies with the requirement of the Standards discussed above.

o 20 While the present invention has been described and illustrated with respect to a hydraulic jack, it will be readily apparent to the skilled addressee that the concept can also be applied to a mechanical screw jack where the circumferential grooves 22 will be provided around the body of the mechanical jack.

25 Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention.

CLAIMS:

1. A vehicle jack and stand including: a base, optionally mounted on wheels; a jack cylinder on the base; and a jack piston, having a head, telescopically mounted in the cylinder and extensible therefrom, the head being engageable with a vehicle to lift the vehicle; wherein: a support stand tube, connected to the piston (and/or the head) coaxially surrounds the jack cylinder; and locking means on the tube are co-operable with complementary means on the cylinder to releasably lock the tube to the cylinder at at least one level of extension of the jack.

2. A jack and stand as claimed in Claim 1 wherein: the base, mounted on wheels, is provided with a handle 15 to enable the jack and stand to be wheeled under a specified jacking point without the operator being positioned below the vehicle; and i remote operating controls are provided at a distal end of ooeo• the handle.

o..

3. A jack and stand as claimed in Claim 3 wherein: *20 hydraulic fluid is selectively introduced into the cylinder to cause the piston, and the tube, to be selectively extended to lift the vehicle.

4. A jack and stand as claimed in any one of Claims 1 to 3 wherein: 25 the locking means includes locking rings or fingers selectively extendible inwardly towards the cylinder for releasable engagement with the complementary means on the cylinder.

A jack or stand as claimed in Claim 4 wherein: the complementary means include peripheral grooves about the wall of the jack cylinder, or teeth, optionally with

I

Claims

6. A jack and stand as claimed in Claim 5 wherein: the locking rings are mounted on guide pins received in slots on cam rings, to selectively move the locking rings into, and out of, engagement with the grooves or teeth on the wall of the jack cylinder.
7. A jack or stand as claimed in Claim 6 wherein: the cam rings are operable by a hydraulic or pneumatic cylinder remotely controlled by the operator.
8. A jack and stand as claimed in Claim 1 wherein: the jack cylinder and piston are substituted by a medical jack, optionally of the screw type, where the support cylinder is connected to the head of the jack screw. DATED this thirteenth day of November 1996. HILLAND PTY LTD By its Patent Attorneys 20 FISHER ADAMS KELLY e~e e *e 8 TITLE: A VEHICLE JACK AND STAND ABSTRACT A vehicle jack and stand (10) has a cylinder (12) and piston (13) operable to raise and support a vehicle. A head (14) on the piston (13) is connected to a stand support tube (20 which surrounds the cylinder (12) and locking rings are selectively moved, by a cam ring (29) into releasable locking engagement with abutment faces (23) in grooves 922) about the cylinder The cam ring (29) is remotely controlled via a control unit (102) on the handle (101), the handle (101) and wheels (100) allowing the jack and stand to be located and operated with the operator at a safe distance from the vehicle. 9*O* 9* 9*99** *eo *o *eoe *oe I I