GB2375332A

GB2375332A - Wheel restraint system

Info

Publication number: GB2375332A
Application number: GB0108569A
Authority: GB
Inventors: Nigel Howard Mckrill
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-05
Filing date: 2001-04-05
Publication date: 2002-11-13
Anticipated expiration: 2021-04-05
Also published as: GB0108569D0; GB2375332B

Abstract

A wheel restraint system for a wheeled vehicle, to restrain a wheel which becomes detached, comprises retaining straps 30 which are connected between an extendable and retractable operating means 5 and part of the wheels 50. The operating means 5 comprises four shock attenuators linked to a pressure boost accumulator 60 which will retract the strap 30 when a wheel is detached to prevent the wheel flailing about in an uncontrolled manner at the end of its tether.

Description

WHEEL RESTRAINT SYSTEM This invention relates to vehicles equipped with wheels, most typically of automobile type, though the invention may be applied also to other types of wheeled vehicle, requiring the retention of their wheels in an accident.

The following description is for a wheel restraint system, for use on racing cars.

Over a period of many years, race car suspension systems have been prone to wheel loss in an accident situation; such loss of wheels having already caused the death of drivers, participants and spectators in many motor races.

The controlling bodies of the sport of motor racing have introduced regulations with the intention of ensuring that the the wheel system or systems and their associated appendages remain with the race car in an accident.

Such legislation has brought about wheel retention systems which generally utilise a strap or straps, these being attached to each wheel via its hub, and the cars hull or body.

Thus far, such systems of wheel retention have not been successful in restraining the wheels in an accident.

Therefore it is the intention of this invention to provide a wheel restraint system capable of restraining the wheels, so that they will remain with the vehicle even when detached from the chassis, and if required, may also pull the wheels back into the car after the initial shock of the accident has been overcome; this to prevent the equipment so retained, from flailing about in an uncontrolled manner on the end of its restraining tether.

Present wheel restraint systems attempt to restrain the wheels by the use of straps which are attached rigidly, to their strap attachment points on the vehicle chassis, with little or no provision being made for the high shock loads occuring in an accident, other than local reinforcement of the strap attachment points.

Whilst such a design path allows the minimum intrusion upon the vehicles design, this method of installing retaining straps, has invariably failed in preventing the separation and loss of the wheel and or suspension systems.

The invention will solve this problem, by restraining the wheels via a shock restraint system incorporating shock load damping, using extensible and retractable restraint means.

A restraint system so equipped will permit a controlled and graduated extension of the restraining system, to reduce the shock loadings to the restraint system attachment to the vehicle and the equipment so attached, in an accident sufficient to separate the wheels from the chassis.

The invention will allow said components to remain with the car, even when the suspension attachment points are separated from the car, being extendably attached, by the restraint strap.

Furthermore the extensible system may be arranged to retract the separated components, selectably or automatically if so required, and for the system to vary its restraint pressure according to the severity of the accident.

The system may be actuated by rapidly changing loads ie negative force or positive force loadings, automatic sensing system or selectively, and may incorporate both compressible, and/or incompressible means for extension and retraction.

An embodiment of the invention will now be described with reference to the accompanying drawings in which; FIGURE 1 shows a perspective view of the wheel restraint system installed on a race car ; FIGURE 2 shows in perspective a pressure boost accumulator ; FIGURE 3 shows in perspective a shock attenuator assembly; FIGURE 4 shows in cut away perspective a shock attenuator assembly; FIGURE 5 shows in cut away perspective a shock attenuator assembly partly extended with port body closed; FIGURE 6 shows in cut away perspective a detail of the port body open;

As shown in Figure 1, the restraint system is shown installed on a race car, comprising four shock attenuator assemblies 5, installed back to back, each being linked by supply lines 65 to pressure boost accumulator 60.

Attached to each of the shock attenuator assemblies 5, is restraint strap 30, which passes through strap guide 40, thence to attachment point 50 at each wheel.

Shown in Figure 2, the pressure boost accumulator 60, is connected to each shock attenuator assembly 5, via supply lines 65, and is arranged to supply increased pressurised operating means 61, to each shock attenuator 5.

As shown in Figure 4, the shock attenuator assembly 5, comprises cylinder 10, piston 12, motivationally controlled by pressurised means 13, shaft 20, port body 25, and fork-strap attachment 26, to which is attached retaining strap 30, secured by shear pin 35. Supply from pressure boost accumulator 60, is delivered via supply line 65, to port 68.

Referring to Figure 5, the supply of increased pressurised operating means 61, delivered via supply line 65, is controlled by port body 25, this being opened by piston 12, when in the maximum extended position shown in Figure 6, the abutment of piston 12 against port body 25, forces it to rotate on thread 69, to align port 67 with supply port 68, allowing the flow of increased pressurised operating means 61 from pressure boost accumulator 60, to be superimposed over the normal operating pressure of shock attenuator 5, thereby increasing pressure to piston 12, to increase system retraction ability when restraint strap 30 extends shaft 20, sufficiently to activate port body 25.

Shear pin 35 is provided, to shear at a predetermined load to prevent breakout of the attenuator assembly 5, in extreme and unforseen operating circumstances.

Each attenuator may be provided with individual boost supply, or may have two sources of boost supply, divided between the four attenuators, or may operate without boost supply or its associated supply mechanisms.

Claims

1. A wheel restraint system for a wheeled vehicle including means for extension and retraction of the wheels, characterised in that extendible and retractable means [5], are attached to extendable and retractable wheel-restraining member 30, attached to a least a part of the wheel.

2. A wheel restraint system as claimed in claim 1, characterised in that increased retraction means [60] is used in conjunction with extendable and retractable means [5] attached to at least a part of the wheel, via wheel-restraining member [30].

3. A wheel restraint system as claimed in claim 1, characterised in that extension and retraction of restraining member [30] attached to at least a part of the wheel, is achieved by pressurised operating means.

4. A wheel restraint system as claimed in claim 1, characterised in that extension and retraction of restraining member [30] attached to at least a part of the wheel, is achieved by electronic operating means.

5. A wheel restraint system as claimed in claim 1, 2 and 3, wherein extension and retraction of restraining member [30], is controlled electronically.

6. A wheel restraint system as claimed in claim 1, wherein extension and retraction of restraining member [30], is achieved by fluidic means.

7. A wheel restraint system as claimed in claim 1, wherein extension and retraction of restraining member [30], is achieved by sprung means.