AU2981701A

AU2981701A - Fixed caravan jack

Info

Publication number: AU2981701A
Application number: AU29817/01A
Authority: AU
Inventors: Bernice W.A. Eshman; Keith Eshman
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-03-24
Filing date: 2001-03-23
Publication date: 2001-09-27

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Names of Applicants: Actual Inventors: Address for Service: Invention Title: KEITH ESHMAN and BERNICE W A ESHMAN KEITH ESHMAN and BERNICE W A ESHMAN Barker Blenkinship Associates Patent Attorneys PO Box 34, CHATSWOOD NSW 2067 FIXED CARAVAN JACK Details of Associated Provisional Application No: PQ6474 filed 24 March 2000 The following statement is a full description of this invention, including the best method of performing it known to me:- FIXED CARAVAN JACK The present invention relates to a caravan or trailer jack of a type permanently affixed to the vehicle.

Caravans, trailers and like vehicles can be difficult to raise from the ground utilising a jack in order that a tyre may be changed. This is due to the fact that car jacks are usually not well suited to utilisation in connection with caravans or trailers. This is due to the fixing points **provided on trailers, the different heights of trailers as compared with motor vehicles, different caravan/trailer suspension systems, uneven ground and other factors.

It is accordingly an object of the present invention to provide a convenient and safe trailer jacking system or at least to provide the market with an alternative.

According to the present invention there is provided a jacking system for a caravan, trailer or like vehicle comprising a transverse track extending substantially from one side of the vehicle to the other; a hydraulic ram pivotally secured to the track adjacent a first end of the ram in such a manner that the ram is capable of sliding along the track and being fixed at either of at least two positions therealong the positions being adjacent either extremity of the track; the pivot facilitating arcuate movement of the hydraulic ram from a retracted first position whereat its downward projection from the underside of the track is minimal to a second position whereat the ram is substantially perpendicular to the underside of the vehicle; a second end of the ram remote from the first end carrying a ground engaging foot; a pump in hydraulic communication with the ram to facilitate extension of the ram so as to effect jacking when the ram is in a position substantially perpendicular to the underside of the vehicle; releasable locking means adapted to maintain the ram in its first position; o.

folding brace means adapted to brace the ram into its operational second position but to fold out of such position to facilitate storage of the ram in othe first position.

S.

One embodiment of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a side elevation of a jacking system in accordance with the present invention; and Figure 2 is an end elevation of a jacking system in accordance with the present invention.

According to the embodiment of figure 1 there is disclosed a track 1 being bolted at 2 to the chassis rails 3 of a vehicle.

The track is mounted transversely with respect to the longitudinal fore/aft axis of the vehicle and is adapted to captivate carriage 4 for sliding movement therealong.

Carriage 4 in turn carries single acting spring return ram 5 with four tonne capacity. In this instance the ram has a five inch stroke. It will be appreciated that the ram 5 is pivotally affixed at 6 adjacent its first and upper end to carriage 4.

.°oooo This pivot facilitates movement of the ram from the "in use" position depicted whereat the ram is perpendicular to the track and carriage to a retracted position whereat the ram lies substantially parallel to the track (not shown) and carriage. This pivoting motion occurs under control of folding over-centre brace 7. Folding brace 7 is comprised of two principal components being upper arm 8 and lower arm 9. Upper arm 8 is pivotally affixed at 10 to an upper extremity of lower arm 9 and at its opposite end it is pivotally affixed to carriage 6 by pivot bolt 11.

Lower arm 9 is similarly pivotally affixed at 13 to collar 12 about the lower extremity of ram 5. Brace 7 is in this instance an over-centre device such that when it is pushed in the direction indicated by arrow 14 it assumes a locked orientation whereat stop 15 on the upper extremity of arm 9 bears against the underside of the lower extremity of upper arm 8 above pivot point 10. Release of the over-centre action of the brace is achieved by merely pulling down adjacent the mid-length of the brace in a direction opposite to direction 14.

It will be appreciated that adjustment may be provided in order to ensure correct working of the over-centre brace and this adjustment may be provided by way of movement of collar 12 about the lower extremity of ram 5 or alternatively by a screw threaded arrangement at 16 which allows for slight lengthening or contraction of lower arm 9.

oooo *.The lower extremity of ram 15 is provided with foot 17 pivotally :attached thereto at 18, the pivot being present in order to accommodate uneven ground.

It will be appreciated that by sliding carriage 4 along track 1 ram 5 may be moved from one side of the vehicle to the other in order to accommodate jacking of either one side of the vehicle or the other. Stop and locking means (not shown) are provided in order to maintain the carriage in a fixed position with respect to the track during a jacking operation.

Rod 19 is provided in order to facilitate moving the carriage along the track by manipulation of that end of the rod 20 not affixed to the carriage.

The rod may be provided in detachable segments in case the vehicle should be parked against a wall which precludes pulling the rod 6 substantially beyond the sides of the vehicle in order to effect movement of the carriage. It will be observed that stop 21 is provided in order to prevent movement of the ram into an other than vertical position with respect to the track although the primary constraint in respect of this movement is provided by brace 7.

Locking means are provided in order to secure the ram in its retracted ,o ~(not shown) position substantially parallel to the track and carriage. A hand pump and flexible hydraulic lines (neither shown) are provided in *order to actuate the ram. It will be appreciated that by use of the carriage S. S the ram may be moved from one side of the vehicle to the other i according to which side of the vehicle requires jacking at the time. As the 5555

S

ram is fully secured to the vehicle at all times and the brace it provides a safe working environment when a tyre needs to be changed or other

S

service performed on the vehicle. There is no possibility of the fixing of S. the ram to the vehicle failing due to movement of the vehicle or movement of the ground or misalignment of the jack.

Claims

1. A jacking system for a caravan, trailer or like vehicle comprising a transverse track extending substantially from one side of the vehicle to the other; a hydraulic ram pivotally secured to the track adjacent a first end of the ram in such a manner that the ram is capable of sliding along the track and being fixed at either of at least two positions therealong the positions being adjacent either extremity of the track; the pivot facilitating arcuate movement of the hydraulic ram from a retracted first position whereat its downward projection from the underside of the track is minimal to a second position whereat the ram is substantially perpendicular to *the underside of the vehicle; a second end of the ram remote from the first end carrying a ground engaging foot; a pump in hydraulic communication with the ram to facilitate extension of the ram so as to effect jacking when the ram is in a position substantially perpendicular to the underside of the vehicle; releasable locking means adapted to maintain the ram in its first position; folding brace means adapted to brace the ram into its operational second position but to fold out of such position to facilitate storage of the ram in the first position.

2. A jacking system in accordance with claim 1 hereof wherein the folding brace device is a brace having a first end fixed at the same 8 height as the pivot for the ram but spacially removed therefrom and having a second end fixed to the ram at a position removed from the pivot.

3. A jacking system in accordance with claim 2 hereof wherein the folding brace substantially comprises two arms joined at a pivot and capable of folding about said pivot relative to each other but being designed so as to form an over-centre locking device capable of locking the two arms when they are folded out into their extended position and the ram is substantially perpendicular to the o underside of the vehicle.

4. A jacking system in accordance with any one of claims 2-3 hereof wherein the pivot adjacent the first end of the ram is affixed to a carriage slideably engaged with the track and the upper pivot point for the folding brace is also on the carriage substantially at the same height as the pivot for the ram.

A jacking system in accordance with any one of claims 2-4 hereof wherein the folding brace is provided with adjustments so that its longitudinal reach in its extended position may be extended or contracted.

6. A jacking system in accordance with any one of the preceding claims hereof wherein a stop is provided for the ram in order to prevent folding of the ram from a position substantially horizontally aligned with the underside of the vehicle to a predetermined position not substantially exceeding that at which the ram is perpendicular with the underside of the vehicle.

7. A jacking system in accordance with any one of the preceding claims hereof wherein the pump for the hydraulic ram is a hand pump affixed to the vehicle and the ram is of the single acting spring return type.

8. A device in accordance with any one of the preceding claims S•hereof wherein the hose between the pump and the ram is flexible hose in order to accommodate movement of the ram along a track. o•

9. A jacking system in accordance with any one of the preceding claims hereof wherein the transverse track is just behind the rearmost wheel of the vehicle and as close as practicable thereto.

A jacking system in accordance with claim 4 hereof having rod means attached to the carriage and extending along the axis of the rails so as to facilitate movement of the carriage along the rail by pushing or pulling the rod.

11. A jacking system in accordance with claim 10 hereof wherein the rod means is adjustable in length so that the rod may not extend excessively past the side of the vehicle irrespective of the position of the carriage on the rail.

12. A jacking system in accordance with any one of the preceding claims hereof wherein the ground engaging foot attached to the second end of the ram remote from its pivot is itself pivoted so as to accommodate uneven ground. DATED this 21 s t day of March 2001. KEITH ESHMAN and BERNICE W.A. ESHMAN by their Patent Attorneys Barker Blenkinship Associates