AU726300B2 - Vehicle suspension - Google Patents

Description

S F Ref: 414610

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: R J Walsh Son Pty Limited 122 Gow Street Padstow New South Wales 2211

AUSTRALIA

James Walsh Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Vehicle Suspension ASSOCIATED PROVISIONAL APPLICATION DETAILS [311 Application No(s) [33] Country P05961 AU [32] Application Date 2 April 1997 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815 VEHICLE SUSPENSION Field of the Invention The following invention relates to a suspension system particularly adaptable for use in a sulky used in harness racing. However, it should be appreciated that the suspension system is equally adaptable for use in trailers, caravans or other vehicles which may be towed by animals or motorised vehicles.

In harness racing, single seat vehicles known as "sulkies" carry a driver and are pulled behind horses around oval tracks at speeds of up to 60 kilometres per hour. In addition to carrying the driver, the function of the sulky is to cause as little impediment to the progress of the horse as possible. All sulkies currently used in all harness racing nations lack an effective sprung and damped suspension whereby the vehicle's unsprung weight is reduced substantially and whereby the energy the horse must provide to overcome the vertical oscillations of the sulky and driver caused, inter alia, by contact between the sulky's tyres and the indentations in the track surface produced by the impact of the horse's hooves, may be reduced.

The track surface is normally "conditioned" between races. During conditioning, .o the surface is harrowed to a depth of about 75mm to 100mm and then lightly rolled to a S' smooth surface. The impact of the hooves of horses will typically cause indentations to a •depth of some 30 to 50mm from the highest adjacent track surface.

The horse itself oscillates vertically during pacing, typically leaving the ground all together once every seven odd metres of distance at racing speeds. The ends of the sulky shafts oscillate vertically with the horse and, with the rigidly mounted wheel axles serving as a fulcrum, may cause the sulky's driver to oscillate vertically at the same rate but with lesser amplitude.

Another problem frequently occurs with conventional sulkies whereby adjacent sulkies will lock together when the formed between the undercarriage outer leg and stay of one sulky drops into the formed by the outer carriage leg and wheel stay of the adjacent sulky. A further problem is that the nested Vs thus locked together may very 30 strongly resist separation by relative forward or backward movement of the sulkies.

Punctures are a not infrequent occurrence in harness racing. In the event of a puncture, it is necessary that the affected wheel be quickly and easily removed. The wheels of conventional sulkies are retained by a pull-through axle which effectively locks together two arms of the wheel stay, two upright undercarriage members, and the wheel itself. In order to insert this axle, the wheel, undercarriage and stay members must all be aligned manually.

One major impediment to the wider use of stub axles on sulkies has been the propensity of wheels so mounted to interlock in close racing. The inner and outer struts of conventional designs are rigidly fixed together, so that a conventional strut arrangement is incapable of easily allowing the removal of a wheel fitted to a stub axle.

[N:\LIBLL]00860:KEH 2 Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages and/or more generally to provide an improved suspension system particularly adapted for use in a harness racing sulky.

Disclosure of the Invention There is disclosed herein a sulky suspension system having: a frame; a first axle having a proximal end thereof pivotally mounted to the frame, a distal end of said first axle being adapted to rotatably receive a first wheel; a second axle having a proximal end thereof pivotally connected to said distal end of said first axle, a distal end of said second axle being adapted to rotatably receive a second wheel; first resilient means associating the distal end of the first axle with the frame so as to control movement of said first wheel; and too second resilient means associating the distal end of the second axle with the frame so as to control movement of said second wheel.

Preferably, the suspension system further has one or more struts connected to the to first axle nearby its distal end, remote ends of the struts being pivotally mountable to a sulky to which the suspension system is attached.

Preferably, the suspension system is so adapted that axes about which the axles pivot cross each other. Typically, the pivot axes cross at approximately 900 with respect S•to one another.

Preferably, said first and second axles are substantially straight.

Preferably, the first and second resilient means are each combined spring and 25 damper units.

There is further disclosed herein a sulky to which the above disclosed suspension system is attached.

[R:\LIBLL]09893 .doc.MFF 't 3 Definitions As used herein the word "frame" is intended to mean any rigid supporting structure to which other components can be connected. This might encompass a single elongate rigid beam or a number of rigidly interconnected components, the conglomeration of which can provide means to which other components can be affixed.

As used herein the term "resilient means" is to encompass a spring, a combined spring and damper unit or separate spring and damper units.

Brief Description of the Drawings Preferred forms of the present invention will now be described by way of example only with reference to the accompanying drawings, wherein: Fig. 1 is a schematic side elevational view of a sulky, Fig. 2 is a schematic rear elevational view of the sulky of Fig. 1, Fig. 3 is a schematic front elevational view of the sulky of Figs. 1 and 2, Fig. 3A is a schematic front elevational view of a sulky having alternative axles, 15 Fig. 3B is a schematic front elevational view of a sulky having yet further alternative axles, Fig. 4 is a schematic plan view of the sulky of Figs. 1 to 3, Fig. 5 is a schematic rear elevational view of a sulky showing the suspension system fully contracted, Fig. 6 is a schematic rear elevational view of a sulky showing the suspension system in a fully extended position, Fig. 7 is a schematic side elevational view of a shaft clamp, Fig. 8 is a schematic end elvational view of the clamp of Fig. 7, and Fig. 9 is a schematic illustration of the first or off-side axle mounting arrangement to the frame of the sulky.

Description of the Preferred Embodiment In Figs. 1 to 3 of the accompanying drawings there is schematically depicted a sulky 10. Sulky 10 has a wheel 11 which is rotatably attached to the first or off-side axle 12. Axle 12 is laterally located by a rod end to an undercarriage leg 13 at point 14.

Undercarriage leg 13 forms part of an undercarriage frame 30. Axle 12 is rigidly affixed to a strut 15 through a clamp 16. The upper end of strut 15 is pivotally attached to the shaft 17 of the sulky at a point 18 by a rod end to a clamp. An outer strut 19 is pivotally attached to strut 15 at a point adjacent to the latter's attachment to the shaft 17 at point 18.

A An off-side wheel 11 is rotatably mounted to the distal end of the off-side axle 12.

43 Effectively, the wheel 11/axle 12 assembly pivots about an axis A passing through points [R:\LIBLL09893.doc:MFF 14 and 18. This pivotal rotation is constrained by a combined spring and shock absorber unit 20 which connects clamp 16 to the undercarriage 30 of the sulky Near-side wheel 21 is rotatably attached to a second or near-side axle 22 which is pivotally attached to the clamp 16 at point 50 of the first or off-side axle 12 as best seen in Figures 5 and 6. Axle 22 is rigidly affixed to a strut 23 through a clamp at point 24. The upper end of strut 23 is pivotally attached to shaft 25 of sulky 10 at a clamp at point 26.

The upper end of strut 23 is pivotally attached to shaft 25 at a clamp at point 26. An outer strut 27 is attached at its lower end to axle 22 by a screw at point 28. At its upper end, the strut 27 is pivotally attached to strut 23 adjacent to point 26. Effectively, the wheel 21/axle 22 assembly pivots about an axis B passing through points 26 and 16. This rotation is constrained by a combined spring/shock absorber 29 connected between the undercarriage 30 and the clamp at point 24.

The undercarriage frame 30 is rotatably attached to the shafts 17 and 25 by two "U"-bolts at points 31 and 32. It should be noted that the shafts 17 and 25 continue to a S is seat support 37 which along with undercarriage frame 30 supports a driver's seat 35. The i: sulky 10 also has a cross member 38 to which there is affixed a pair of foot holders 36.

The undercarriage 30 is prevented from rotating by means of a strut 33 which rigidly joins point 14 with shaft 25 at point 34.

In Fig. 5 there is shown the rear elevational view of another embodiment of a

S

o* o 20 sulky with suspension system fully compressed in a bottomed-out state. In this condition, :oo: the near-side wheel 21 maintains a substantially vertical orientation, whereas the off-side wheel 11 has undergone an angular movement which is roughly twice that as undergone by near-side wheel 21. This results from the fact that the axle 12 to which off-side wheel 11 is mounted is connected directly to the frame 30. By comparison, the near-side axle S 25 22 is not mounted directly to the frame but, to the distal end of axle 12 at point In the embodiment of Fig. 3A, an alternative axle arrangement is provided.

Rather than connecting the near-side axle 22 to the distal end of axle 12, this end is mounted directly to a cross member or frame member 30 which replaces the undercarriage of the embodiment of Figs. 1 to 3. Member 30 is typically a hollow section which is rectangular in cross-sectional shape. Furthermore, each axle 12 and 22 is provided with a bend 42 which provides greater clearance between the mid-portions of each axles 12 and 22 and the ground.

In order to provide even more ground clearance, and as shown in Fig. 3B a pAiAv second bend 43 can be provided in each axles 12 and 22. For example, a first portion 44 l of axle 12 might extend at an angle of approximately 380 from horizontal. The second [R:LIBLL]09893.doc:MFF 4a portion 45 might extend at an angle of about 160 from the line of portion 44. These angles could of course vary.

Each of the axles of Figs. 3A and 3B would present a compromise in stiffness in terms of lateral displacement. Where lateral stiffness is required, the axle arrangement of Fig. 3 is more appropriate. A certain amount of ground clearance is required by legislation in some jurisdictions for racing sulkies. The straight axle embodiment of Fig.

3 might still however be used for training purposes.

In Fig. 6, the suspension system is shown in its fully extended position wherein off-side wheel 11 has undergone substantial angular movement, whereas near-side wheel 21 remains substantially vertical.

In Figs. 7 and 8 there is shown a shaft clamp typically used at points 18 and 26.

The clamp is adapted to surround a tubular member such as the struts 17 and 25 and is .i q. a q [R:\LIBLL] 09893 doc: MFF tightened thereon by means of a threaded fastener passing though an internally threaded aperture 40 in flange 41.

Fig. 9 shows the arrangement whereby axle 21 is pivotally mounted to undercarriage leg 13.

As a result of the present invention, both forms of vertical oscillation of the driver as noted earlier are reduced. This serves to both reduce the horse's energetic cost of locomotion and to increase the driver's comfort. Thus, the sulky is both faster and more comfortable. In addition, the damped independent suspension should provide superior road-holding on uneven surfaces. The present invention should increase safety during racing through a reduction in the lateral sliding on corners resulting from the substantially vertical maintenance of the orientation of near-side wheel 21. The suspension system should increase safety during racing through a reduction in lateral sliding on corners.

Also, since the sulky has no Vs the problem of interlocking sulkies is greatly reduced, both in respect of mixed racing with conventional sulkies and in racing where all starters are equipped with the present invention.

Also, an advantage of the present invention is that through the use of stub axles and the removal of a single retaining screw, the outer struts 19 and 27 can drop away allowing easy removal and replacement of the wheels. Where the outer struts are provided with a slotted end, only such slotted ends need be visually aligned before the retaining screw is replaced. The outer struts 19 and 27 serve to prevent the wheel of an adjacent sulky locking with the nearest wheel of a sulky fitted with the present invention.

The present invention also allows free movement of the outer strut in both the horizontal and vertical planes, permitting the wheel to be easily removed, while still offering the essential protection from wheel lock. In the close and competitive world of harness racing, this is an important feature.

Without significant weight penalty the present invention provides a sulky with less resistance to forward motion, enhanced road-holding, improved driver comfort, easier and quicker wheel replacement, and improved resistance to locking outer members with adjacent vehicles.

It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, while the present system is shown fitted to both offset and symmetrical sulkies of predominantly tubular steel construction, it is intended to be fittable to both conventional race sulkies and to work sulkies of aluminium or other metals or timber or composite construction, where the smoothness of the ride available will appeal to many trainers who suffer back problems brought on by the harsh and unforgiving nature of present rigid suspension systems. Also, the invention is applicable in its broad sense to trailers, caravans and other vehicles capable of being drawn by a powered vehicle or animal.

[N:\LIBLL]00860:KEH

Claims (3)

1. 2. The suspension system of claim 1, further having onte or more struts connected to the first axle nearby its distal end, remote ends of the struts being pivotally mountable to a sulky to which the suspension system is attached.
2. 3. The suspension system of claim 1, wherein axes about which the axles pivot cross each other. The suspension system of claim 3, wherein the pivot axes cross at approximately 900 with respect to one another.
3. 205. h suspension system of claim 1,wherein the first and second axles are substantially straight. 6. The suspension system of any one of the preceding claims, wherein said first and second resilient means are each combined spring and damper units. 7. A sulky suspension system substantially as hereinbefore described with 25 reference to Figs. 1 to 3 and 4 to 9 of the accompanying drawings. 8. A sulky having attached thereto the suspension system of any one of the preceding claims. Dated 31 August, 2000 R J Walsh Son Pty Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON IUAIV A 1TE> (RA\UBLfLO9893.dc MIF 2