SAFETY SYSTEM AND SENSORS THEREFOR

Field of the Invention

This invention relates to a safety system, and more particularly, but not exclusively, to a safety system for a vehicle for protecting an occupant during an impact.

Background of the Invention

It is known to provide head and neck supporting devices for use in racing vehicles so as to protect occupants of vehicles during collisions. One such device is disclosed in United States Patent No. 6,009,566 and includes a collar which is worn over the occupant's shoulders and beneath shoulder belts of a racing harness. A helmet worn by the occupant is tethered to the collar so as to transfer forces from the helmet to the collar, thus reducing forces transmitted to the neck of the occupant. However, such devices have disadvantages in that the helmet must be tethered tightly to the collar so as to be effective during a collision, and thus the driver is limited in his or her freedom of movement during racing. Moreover, this device, although effective in restraining the head in front-end collisions, nevertheless still enables rolling of the head from side to side and is thus less effective in protecting the occupant's head and neck in side collisions.

Another form of previously proposed racing head restraint device is disclosed in United States Patent No. 6,499,149. This device uses a harness system which is worn around the occupant's body for transferring load from the head to a lap belt by means of helmet tethers connected to vertical straps of the harness. However, the helmet tethers must be worn tight in order to sufficiently restrict movement of the helmet during a collision, and thus the occupant is limited in his or her head movement during racing. The helmet tethers have also been found to be less effective in side collisions where the helmet is still allowed to move relative to the occupant's body despite the tethers.

Examples of the present invention seek to provide a safety system which overcomes or at least alleviates one or more of the above disadvantages of previously proposed head restraint devices.

Summary of the Invention

In accordance with one aspect of the present invention, there is provided a safety system for an occupant of a vehicle, the safety system including a restraining mechanism to secure the head of an occupant of the vehicle and a sensor, the mechanism having a first condition which allows movement of the occupant's head relative to a brace member and a second condition in which the occupant's head is restrained from movement relative to the brace member, wherein the mechanism adopts the second condition in response to the sensor sensing a predetermined event.

Preferably, the sensor is for sensing a predetermined acceleration/deceleration and/or orientation of the vehicle. Preferably, the sensor senses a predetermined horizontal and/or vertical acceleration of the occupant's seat, and/or an inversion of the occupant's seat. Preferably, the safety system is provided with a first sensor for sensing horizontal acceleration of the occupant's seat and a second sensor for sensing vertical acceleration and/or inversion of the occupant's seat.

Preferably, the brace member is a rigid member. More preferably, the brace member is adapted for supporting the occupant's back such that, when the restraining mechanism is in the second condition, the brace member supports the occupant's head in position relative to the occupant's back. In one form, the brace member includes a cradle into which the occupant's helmet is restrained when the restraining mechanism is in the second condition. Preferably, the brace member is pivotal about an axis extending laterally of the occupant's body, and in the proximity of the occupant's waist. Even more preferably, the brace member is or is part of a seatback of the occupant's seat, and is pivotal relative to a seat portion of the seat.

Preferably, the restraining mechanism adopts the second condition in response to activation of a manual override operable by the occupant.

Preferably, the restraining mechanism includes a retractable strap which is anchored to the brace member at one end and is adapted for coupling to a helmet of the occupant at an opposite end. More preferably, the retractable strap is anchored to the brace member by way of an inertia reel. Even more preferably, the restraining mechanism adopts the second condition by controlled retraction of the strap. Preferably, the strap has limited elasticity.

Preferably, the strap is adapted for coupling to the helmet by way of a selectively disengageable bracket which receives a connector mounted to the helmet. More preferably, the bracket is disengaged by pulling one or both actuators located on either side of the occupant's head. Even more preferably, when decoupled from the helmet, the bracket is automatically returned to a position behind the occupant's head. This enables the occupant to effect coupling by simply leaning his or her head back so as to engage the connector in the bracket.

Preferably, the safety system is able to operate other systems in response to activation of the sensor and/or the manual override. Such other systems may include, for example, a fuel shut-off system, a fire-retarding/extinguishing system, and/or a battery isolation system. More preferably, the safety system includes a reset actuator operable by the occupant for resetting the safety system by moving the restraining mechanism from the second condition to the first condition.

In accordance with another aspect there is provided an air bag system for use with a safety system as described above, wherein an air bag of the air bag system is adapted for inflation in response to activation of the sensor and/or the manual override.

Preferably, the air bag is reusable.

In accordance with another aspect of the present invention, there is provided a sensor for a vehicle safety system, including a first member spaced apart from a second member, wherein the sensor is movable from a rest condition in which the first member is spaced from the second member to an activated condition in which the first member contacts the second member in response to a predetermined acceleration of one of the two members relative to the other member.

Preferably, the first member is suspended relative to the second member. More preferably, the first member is suspended relative to the second member by at least one flexible member. Even more preferably, the flexible member is a resilient member.

In one form, the resilient member is a spring. Sensitivity of the sensor may be adjustable by adjusting tension in the spring.

In another form, the resilient member is a membrane.

Preferably, the sensor is adapted to sense acceleration in a plurality of directions. For example, the sensor may be adapted to sense acceleration from rear-end collisions and well as front-end collisions. The sensor may also be adapted to sense acceleration in directions lateral to the vehicle.

Preferably, the sensor is adapted to sense orientation. More preferably, the sensor includes an inversion sensing device. Even more preferably, the inversion sensing device is included by the first member containing a weight which is movable within the first member so as to activate a switch under its weight when the sensor is inverted. In one form, the sensor includes a housing having an upper switch, the first member in the form of a lower switch, and an actuating member which is free to move within the housing, wherein when the sensor is in an upright configuration the actuating member is supported by the second member in the form of a cradle suspended from the housing by a spring, such that the lower switch is actuated by the actuating member and cradle in response to

the sensor being subjected to a predetermined upward acceleration, and the upper switch is actuated by the actuating member falling from the cradle in response to inversion of the sensor.

In accordance with another aspect, there is provided a backboard adapted for being hingedly mounted at a lower end thereof to a seat in a vehicle, wherein the backboard includes a helmet restraint for coupling the backboard to a helmet of an occupant.

Preferably, the backboard includes a quick release for decoupling the hinge so as to remove the backboard from the seat.

Preferably, the helmet restraint includes an extendable strap mounted at one end to the backboard and having a coupling at an opposite end for coupling to the helmet. More preferably, the helmet restraint includes a lock for locking extension of the strap in response to a sensor sensing a predetermined event.

In accordance with another aspect, there is provided a restraint harness for securing a an occupant's head during extraction of the occupant from a vehicle.

Preferably, the harness includes straps adapted for fastening the harness relative to a structure behind the occupant. More preferably, the straps are adapted for fastening the harness relative to a backboard behind the occupant.

Alternatively, the straps are adapted for fastening the harness relative to a headrest behind the occupant's head.

In another aspect, there is provided a hood for covering a helmet of a driver to protect the driver from fire and/or fire extinguishing material and/or penetration in the case of an explosion.

In another aspect, there is provided a rug for covering a body of a driver to protect the driver from fire and/or fire extinguishing material and/or penetration in the case of an explosion.

Preferably, the hood and the rug are formed of material having at least one fire- retardant layer and at least one strengthening layer. More preferably, the material has a plurality of fire-retardant layers sandwiching said at least one strengthening layer. Even more preferably, the material is quilted.

In another aspect, there is provided a safety system for a vehicle, the system including a sensor and a device for operating a reel of a seatbelt of the vehicle to lock the seatbelt from extension in response to the sensor sensing a predetermined event.

Preferably, the sensor is as described above.

Brief Description of the Drawings

The invention is described, by way of non-limiting example only, with reference to the accompanying drawings in which:

Figure 1 is a side view of a seat of a safety system in accordance with an example of the present invention;

Figure 2 is a rear view of the safety system of Figure 1;

Figure 3 shows a base frame, seat sub frame and locking mechanism of the safety system of Figure 1;

Figure 4a shows a front view of a helmet cradle of the safety system of Figure 1 ;

Figure 4b shows a bracket for coupling to a helmet of the safety system of Figure 1 ;

Figure 4c shows a top view of the bracket of Figure 4b, shown during coupling to a connector;

Figures 5 a and 5b are side and rear views of a retraction mechanism of the safety system of Figure 1;

Figures 6a and 6b are rear and side views of a helmet activation switch mechanism of the safety system of Figure 1;

Figures 7a and 7b are side and rear views of a retraction stop mechanism of the safety system of Figure 1;

Figure 8 is a top view of a horizontal acceleration sensor of the safety system of Figure 1;

Figure 9 is a side view of a vertical acceleration and inversion sensor of the safety system of Figure 1;

Figures 10a and 10b show top and side cross-sectional views of an alternative sensor arrangement;

Figures 11a and l ib show top and side cross-sectional views of another alternative sensor arrangement;

Figures 12a and 12b show front and side views of a backboard;

Figures 13a, 13b and 13c show top, front and side views of a seat;

Figures 14a and 14b show side and top views of a helmet restraint harness;

Figures 14c and 14d are diagrammatic side and top views of a head restraint harness shown fitted to an occupant of a vehicle, and Figure 14e is a diagrammatic view of the head restraint harness shown prior to fitting;

Figure 15a is a top view of a protective rug;

Figure 15b is a perspective view of a protective hood;

Figure 15c is a cross-sectional view of material from which the rug of Figure 15a and the hood of Figure 15b are formed;

Figure 16 is a side diagrammatic view of a budget safety system for an occupant of a vehicle;

Figure 17 is a diagrammatic view of a switch mechanism for activation by a sensor arrangement;

Figures 18a to 18d are diagrammatic views of a reusable air bag;

Figure 19 is a diagrammatic view of an ignition/fuel pump shut down assembly; and

Figure 20 is a diagrammatic cross-sectional view of a modified inversion sensor.

Detailed Description

A safety system 10 for an occupant of a vehicle is shown in Figures 1 to 17 and includes a restraining mechanism 12, a sensor 14, and a brace member 16. In the example shown, the restraining mechanism 12 includes a retractable strap 18 which is anchored to the brace member 16 at one end by way of an inertia reel 20 (see Figure 2). An opposite end of the retractable strap 18 extends forwardly through a helmet cradle 22, and has a

disengageble bracket 24 for coupling to a helmet of the occupant. The strap 18 is retractable by way of a drive motor 26 and drive chain 28 such that the restraining mechanism 12 is movable between a first condition which allows movement of the occupant's head relative to the brace member 16 and a second condition in which the occupant's head is restrained from movement relative to the brace member 16. The restraining mechanism 12 is movable from the first condition to the second condition automatically in response to the sensor 14 sensing a predetermined event.

Advantageously, the safety system 10 is able to be incorporated into the occupant's seat 30, for example the driver's seat of a racing car, and can be kept in the first condition during racing which allows the occupant to have sufficient freedom of movement of his or her head so as not to interfere with driving of the vehicle. Further, as the retractable strap

18 is anchored to the brace member 16 by way of the inertia reel 20, the inertia reel 20 is able to be chosen with a suitable tension so as to prevent excessive movement of the occupant's helmet relative to the brace member 16, for example when high G-forces are experienced.

The sensor 14 is a horizontal acceleration sensor which senses predetermined events in the form of predetermined levels of horizontal acceleration (positive or negative) which correspond to forces on the occupant's neck deemed sufficiently high that movement of the restraining mechanism 12 to the second condition is necessary. It is foreseen that the predetermined level of acceleration required to activate the restraining mechanism 12 to the second condition will be chosen such that it is in the order of magnitude experienced only during collisions so that the restraining mechanism 12 does not unwantedly move to the second condition during normal racing/driving.

In the example shown, the restraining mechanism 12 is also movable from the first condition to the second condition automatically in response to a second sensor sensing a predetermined event in the form of a predetermined vertical acceleration and/or inversion of the occupant's seat and vehicle. Accordingly, the restraining mechanism 12 will automatically be brought to the second condition in the event that the vehicle becomes

airbome and lands sufficiently hard that the predetermined vertical acceleration is reached. Also, if the vehicle is to become inverted during a roll, this will be sensed and the restraining mechanism 12 will be brought automatically to the second condition so as to protect the occupant. The second sensor 32 (see Figure 9) may be located on the occupant's seat 30 or, alternatively, may be located elsewhere in the vehicle.

The safety system 10 may also include other mechanisms for activating movement of the restraining mechanism 12 to the second condition. With particular regard to Figure 2, the example safety system 10 of the drawings also has a helmet activation mechanism 34 in addition to the sensors 14, 32 for activating the safety system 10. More particularly, the helmet activation mechanism 34 activates movement of the restraining mechanism 12 from the first condition to the second condition in response to abrupt forward movement of the occupant's head.

A retraction stop mechanism 36 is provided on a rear side of the helmet cradle for arresting retraction of the strap 18 at a specified position corresponding to the restraining mechanism 12 being in the second condition, such that the drive motor 26 is switched off when the retractable strap 18 reaches the desired position.

Primary power is fed to the safety system 10 from an electrical system of the vehicle. However, if the primary power supply fails, a backup power supply from a battery storage 38 is used. The safety system 10 is also provided with indicators which show the occupant and scrutineers the readiness or state of the safety system 10, indicating whether it is running on the primary power supply or power from the battery storage 38. Accordingly, it can be determined if the primary power supply has failed in which case scrutineers may stop the vehicle from being used.

With reference to Figure 2, the safety system 10 further includes a relay cluster 40 for control of operation of the electrical components of the safety system 10, and an external connector 42 for connection with other systems such that the safety system 10 is able to operate these other systems in response to activation of the sensors 14, 32, the

helmet activation mechanism, or other activation means. Such other systems may include, for example, a fuel shut-off system, a fire-retarding/extinguishing system, an ignition isolation system, and/or a battery isolation system. The safety system 10 may also include a reset actuator (not shown) operable by the occupant for resetting the safety system 10 by moving the restraining mechanism 12 from the second condition to the first condition. Accordingly, the safety system 10 may be reset in the event that the driver and vehicle are still able to continue racing after a minor collision in which the safety system 10 is activated. A manual override (not shown) may be incorporated with or near the reset system to enable manual overriding of the safety system 10. The manual override feature may be used, for example, when an experienced driver is aware in advance that he or she is going to crash, such that the safety system 10 is able to secure the driver's head, neck and back in alignment prior to the collision.

The brace member 16 is a rigid member which is adapted for supporting the occupant's back such that, when the restraining mechanism 12 is in the second condition, the brace member 16 supports the occupant's head in position relative to the occupant's back. As such, with the safety system 10 activated at the start of a crash, the driver is protected through the remainder of the crash as if strapped to a rigid backboard, so that alignment of the occupant's body is maintained, and straining or breakage of the neck may be prevented. This is of particular advantage as many accidents occurring during racing involve several impacts in succession.

When the restraining mechanism 12 is in the second condition, the occupant's head is restrained in the helmet cradle 22 located at a distal end of the brace member 16. The helmet cradle 22 is formed so as to extend around sides of the occupant's helmet for providing further support to the occupant's head in side impacts. A proximal end of the brace member 16 is pivotable about a hinge 44 which extends laterally and rearwardly of the occupant's body when seated, and in the proximity of the occupant's waist. In the example shown, the brace member 16 forms a central part of a seat back 46 of the occupant's seat 30, and is pivotable relative to a seat portion 48 of the seat 30. As such, by incorporating the hinged brace member 16, the safety system 10 is able to prevent or at

least reduce injuries to the occupant where a safety harness fails or is worn loose, as is known to be done, particularly by inexperienced drivers. Where a safety harness is worn loose or fails, the body of the occupant is allowed to travel forwardly during a collision. However, by virtue of the pivotable brace member 16, the occupant's head, neck and back move forward in alignment provided by the rigid brace member 16. With reference to Figure 1, the brace member 16 is shown in both a rearward position 16a and a forward position 16b.

The seat 30 may be manufactured from aluminium and bolted to a seat subframe 50 made from tubular steel. The seat 30 and subframe 50 are installed in a vehicle by attachment of the subframe 50 to a base frame 52. This may be achieved by way of one or more forward flanges or hooks 54 of the subframe 50 which are inserted beneath a front bar of the base frame 52, and by way of a locking mechanism 56 for locking a seat back 58 of the seat subframe 50 to a seat back 60 of the base frame 52. With particular reference to Figure 3, the locking mechanism 56 includes a hinged clasp 62 which is able to be locked in front of a flange 64 of the seat back 58, by way of a locking bar 66 and locking pins 68. As such, the seat 30 is able to be quickly released from a vehicle by way of the locking mechanism 56, and is designed to be interchangeable so as to enable installation of the seat 30 in any vehicle fitted with the base frame 52. Accordingly, drivers can individually personalise their seat and safety system according to their body type, comfort and preferences. Advantageously, in races requiring a driver change, different drivers are able to quickly and easily install and remove their seats to and from the vehicle. The seat subframe 50 includes holes 70 for attachment of the seat 30 to the seat subframe 50, and holes 72 for attachment of a racing harness.

Mountings for a five point harness may be built into the seat 30, as may be mountings for the subframe 50. Such construction of the seat may be advantageous in saving construction time and in increasing strength of the seat.

The retractable strap 18 may be manufactured from material similar to seatbelt-type material such that the strap 18 has limited elasticity so as to absorb impacts.

With reference to Figures 4a to 4c, one end of the strap 18 is adapted for coupling to the occupant's helmet by way of the bracket 24. The bracket 24 has a connector in the form of a bar 74 for connection to an end of the strap 18. The bracket 24 has a pair of disengageable jaws 76 for receiving a connector 78 which protrudes rearwardly from the occupant's helmet. The connector 78 may be attached to the helmet or, alternatively, may be formed integrally with the helmet. As shown in the top view of Figure 4c, the bracket 24 has a trumpeted front plate 80 for guiding the connector 78 into the jaws 76. The trumpeted front plate 80 may be formed from nylon. The jaws 76 are held together in an engaging configuration by way of a spring 82, and are able to be moved apart by levers 84 which are connected to the jaws 76 by linkages 86. Each lever 84 is provided with an actuator in the form of a tether 88, and the tethers 88 are located on either side of the occupant's head. The jaws 76 are disengaged for release of the connector 78 by pulling one or both of the tethers 88. By virtue of the retractable nature of the inertia reel 20, the bracket 24 is automatically returned to the position shown in Figure 4a when the bracket 24 is decoupled from the helmet, thus enabling the occupant to effect coupling by simply leaning his or her head back so as to engage the connector 78 in the bracket 24.

With reference to Figures 5a and 5b, the mechanism for retracting the strap 18 includes a solenoid reel lock 90 for locking the reel from rotation relative to the drive motor 26. Accordingly, when the safety system 10 is activated so as to move the restraining mechanism 12 from the first condition to the second condition, the inertia reel

20 is locked by way of the solenoid reel lock 90, and the drive motor 26 is engaged to retract the strap 18 and thus the occupant's helmet and head to a predetermined secure position governed by the retraction stop mechanism 36. When the reset system is operated, the motor 26 is reversed and the inertia reel 20 is unlocked so that the driver can continue racing with the restraining mechanism 12 in the first condition.

With reference to Figures 6a and 6b, the helmet activation mechanism 34 includes an arm 92, a spring 94, and a micro switch 96. With particular reference to Figure 6b, when the helmet is moved forward abruptly, such as in the case of a collision, the inertia

reel 20 locks and the arm 92 is brought forward in the direction of arrow 98 against the tension force of spring 94. Such forward movement of the arm 92 causes the micro switch 96 to be activated, and this in turn causes the restraining mechanism 12 to be moved from the first condition to the second condition by controlled retraction of the strap 18, as described previously. Retraction of the strap 18 is stopped when the occupant's helmet is moved into the helmet cradle 22 by way of the retraction stop mechanism 36 shown in Figures 7a and 7b. The retraction stop mechanism 36 includes a strike plate 100 and a micro switch 102. At a location of the strap 18 corresponding to the second condition of the restraining mechanism 12, the strap 18 is provided with a change in thickness, for example by sewing the strap 18 to form a double or triple thickness, so as to raise the strike plate 100 to activate the micro switch 102. Activation of the micro switch 102 stops operation of the drive motor 26.

Figure 8 shows detail of the horizontal acceleration sensor 14, which includes a first member in the form of a steel disk 104 which, in a preferred embodiment, has a mass of 80 grams. The steel disk 104 is suspended within a second member in the form of a steel ring 106 by a retainer 108 and a plurality of springs 110. The sensor 14 is movable from a rest condition in which the steel disk 104 is spaced from (ie. is not in direct contact with) the steel ring 106, to an activated condition in which the steel disk 104 contacts the steel ring 106, in response to a predetermined acceleration of one of the two members 104, 106 relative to the other member 106, 104. The steel ring 106 is mounted to a base plate 112 by way of springs 114 which are adjustable so as to adjust the sensitivity of the sensor 14. Micro switches 116 are mounted to the base plate 112 around an outside perimeter of the steel ring 106 such that, during an impact, the steel disk 104 will push against the steel ring 106 and, in turn, the steel ring 106 will operate one of the micro switches 116 closest to the point of impact. A terminal connector 118 is provided for connecting the sensor 14 to the rest of the safety system 10, The sensor 14 may be mounted to an underside of the seat 30, as shown in Figure 2, or alternatively, may be mounted elsewhere on the seat 30 or in the vehicle. Tension in the springs 114 is adjusted by way of a thread and nut arrangement, as shown by reference numeral 120.

Figure 9 shows a sectional view of the second sensor 32 in the form of a vertical acceleration and inversion sensor, taken through a vertical section. The sensor 32 includes a housing 122 having an upper micro switch 124, a lower micro switch 126, and an actuating member in the form of a ball bearing 128. The ball bearing 128 is free to move within the housing 122 and, when the sensor 32 is in an upright configuration, the ball bearing 128 rests in and is supported by a cradle 130 suspended from the housing 122 by a plurality of springs 132. When the sensor 32 is subjected to a predetermined upward acceleration (as set by the tension in the springs 132), the lower switch is actuated by the ball bearing 128 and cradle 130. When the sensor 32 is inverted, the ball bearing 128 falls from the cradle 130 and actuates the upper micro switch 124. Accordingly, sensor 32 is able to activate the safety system 10 when a vehicle in which the sensor 32 is mounted is inverted. Also, when a vehicle becomes airborne and lands with great impact, the sensor 32 will be activated provided that the acceleration (ie. deceleration of downward motion) exceeds a predetermined threshold as set by the tension in the springs 132. The sensor 52 may be mounted upright to the seat 30 or, alternatively, may be mounted upright elsewhere in the vehicle.

The safety system 10 has been described above by way of an example only, and modifications are possible within the scope of the invention. For example, although the seat 30 is described above as being manufactured from aluminium and bolted to the seat subframe 50 which is made from tubular steel, in another example, the seat and/or the subframe and/or the base frame may be formed from carbon fibre. A lightweight metal, such as titanium, may also (or instead) be used for forming the seat, the subframe and/or the base frame.

Examples of the safety system 10 provide the following advantages:

• If the driver of a vehicle is unconscious after an accident, there is no necessity for a crash team to elevate the helmet to open the driver's airway as this is already secured by the safety system 10 during the accident.

• If it is deemed necessary to remove the driver from the car, the driver can be removed while still in the seat as it is already acting as a rigid backboard, ensuring the alignment of the driver's head, neck and back.

• Drivers can individually personalise their own seat and safety system to suit their own body type and comfort, and are able to interchange their seat between different cars fitted with the base frame.

• The seat can remotely operate such things as a solenoid fuel valve, ignition systems, and/or battery isolation systems etc. These will only operate when the car is inverted or the driver actuates the panic button.

The applicant has determined that the sensors 14, 32 and/or other features of the safety system 10 may serve other applications in the automotive industry. For example, one or both of the sensors 14, 32 may be used for activation of safety equipment in cars, such as air bags and remote shut-off systems. The sensors are capable of being mounted anywhere within the car, and sensing impact from any direction will be capable of operating systems in the direction of the impact, thus being more efficient and safer. Also, particularly with trucks, a problem in roll-over accidents is having to access a battery isolation switch. Battery isolation can automatically occur as soon as a truck reaches a predetermined angle, for example 45°, by use of one or more of the sensors 14, 32.

An alternative sensor arrangement 150 is shown in Figures 10a and 10b, and comprises a casing 152 with an inner housing 154 suspended in the casing 152 by a membrane 156. The membrane 156 may be formed of silicon or rubber, to allow dampened movement of the inner housing 154 within the casing 152. The inner housing 154 may be formed of brass and houses a steel ball 157, which is able to move within the housing 154 such that the sensor arrangement 150 is operable to activate a safety system in response to horizontal impact, vertical impact and/or inversion.

Electrical cables 158 are connected to the housing 154, and to a lower contact 160 and an inversion contact 162 mounted to the casing 152. The sensor arrangement 150 relies on stored memory and resistance in the membrane 156 to operate. In the case of horizontal impact or vertical impact, the membrane 156 deforms such that a contact 164 on the underside of the inner housing 154 contacts the lower contact 160 mounted to the casing 152. In the case of inversion, the ball 157 rests on top of a movable contact element

166, causing same to contact with a contact element 168 mounted to the casing 152.

Advantageously, the alternative sensor arrangement 150 has few parts, is simple and inexpensive to produce, and is able to sense lateral impact, vertical impact and inversion.

Owing to efficiency of the alternative sensor arrangement 150 in activating the safety system, use of the helmet activation switch mechanism 34 (shown in Figures 6a and 6b) may not be necessary.

Figures 11a and 1 Ib show top and side cross-sectional views of another alternative sensor arrangement 170, including an alloy base plate 172, an alloy float plate 174 resiliently mounted to the alloy base plate 172, and a nylon case 176 mounted within the alloy float plate 174. A range of vertical movement of the float plate 174 relative to the base plate 172 is represented by the double-headed arrow 178. Electrical connections 180 and brass contacts 182 enable passage of current through the sensor arrangement 170 when the connections 180 are brought into contact by lateral impact, vertical impact or inversion.

A backboard brace member 184 is shown in Figures 12a and 12b. The backboard 184 includes a strap 186, helmet coupling 188 for coupling the strap 186 to an occupant's helmet, and a retraction mechanism 190 for retracting the strap 186 on sensing of a predetermined event. A hinge 192 is provided at a lower end of the backboard 184 such that the backboard 184 is able to pivot relative to a seat to which it is mounted, about an axis in the proximity of the occupant's waist. The backboard 184 may be constructed from carbon fibre and aluminium, or just carbon fibre. It is designed to dissipate shock during an accident, so as to greatly reduce the likelihood of brain injury. The backboard 184 acts

as a shock absorber during a crash and will continue to do so during a multiple impact accident.

Figures 13a, 13b and 13c show top, front and side views of a seat 194 having a mechanism cavity 196 such that a backboard brace member 184 (such as the one shown in

Figures 12a and 12b) can be fitted to the seat 194. The seat 194 also has harness portholes

198 to accommodate a racing harness. Advantageously, the backboard 184 is shaped and the portholes 198 are located such that the backboard 184 does not obstruct passage of a racing harness through the portholes 198. Even if the occupant's racing harness is worn loosely, by virtue of the backboard 184 the occupant's head and back will be supported in relative positioning in an accident so as to prevent or at least minimise neck injury.

Figures 14a and 14b show side and top views of a helmet restraint 200 for assisting a medical crew attending to the scene of an accident. The helmet restraint 200 includes a centre strap 202, crossover straps 204 and chin straps 206 for restraining an occupant's helmet in position, as well as a visor clip 208 for retaining a visor of the helmet in a retracted position. The helmet restraint 200 can be used to secure a driver's head during extraction of the driver from a vehicle, and is particularly useful in cases where the vehicle requires being moved from an inverted position to complete the extraction.

With reference to Figures 14c to 14e, in an adaptation there is provided a disposable head restraint harness 264 for use in securing occupants of a vehicle in road accidents. The disposable head restraint harness 264 includes support straps 266 for securing an occupant's head 267 to their seat, velcro pads 268 for fastening the support straps 266 to a headrest 270 of the seat, foam head supports 272 for preventing movement of the head 267 within the space defined by the fastened support straps 266, and cloth membrane material 274 for contact with the occupant's head 267. Advantageously, the disposable head restraint harness 264 can be used to stabilise the occupants and to free up an emergency crew allowing the extractions to proceed faster, particularly in situations where there are more than one occupant requiring extraction.

A protective rug 210 is shown in Figure 15 a, and is adapted for use in covering a driver during extraction from a vehicle after an impact to protect the driver from loss of body heat, fire, and penetration by sharp objects. A hood 212, as shown in Figure 15b, may also be provided to cover the driver's head during extraction. The rug 210 and hood 212 may be formed from protective laminate material 214 as shown in the cross-sectional diagram of Figure 15c, comprising outer layers of Proban® fire retardant material 216 sandwiching inner layers of Kevlar® strengthening material 218. The protective laminate material 214 may have a quilting-type pattern 220 to maximise strength and durability.

By virtue of the protective rug 210 and hood 212, the driver can be totally encapsulated, for example while the roof of the vehicle is being removed. The driver may be fully restrained under cover of the fire and puncture resistant rug, such that if the car catches fire during the extraction of the driver, the recovery crew are much safer because the crew can stand back and douse the car and driver with foam and safely return to the extraction after the fire is extinguished. The driver would be unaffected by both the fire and foam and will be able to breathe easy because of the captured pocket of air under the hood. Accordingly, if (for example) a driver is seriously injured during a race he/she can be fully restrained in and to the seat by a rescue crew, covered with the protective rug 210 and hood 212, and removed from the car while being secure in the seat.

Figure 16 shows a budget safety system 222 for an occupant of a vehicle, the safety system 222 comprising a backboard 224 which may be similar to the backboard 184 shown in Figures 12a and 12b. The safety system 222 also includes an inertia reel 226 for feeding and housing a strap used to anchor the occupant's helmet to the backboard 224, a helmet coupling 227 attached to an end of the strap, release tethers 228 for releasing the helmet coupling 227 from a helmet, and a hinge 229 for mounting the backboard 224 to a seat. Electrical componentry, including a solenoid 230 and relays 232, is mounted to a rear side of the backboard 224 for controlling operation of the strap. A sensor 234 for activating the system 222 may be in the form of a sensor arrangement 150 as shown in Figures 10a and 10b. An activation switch 236 is provided for manual operation of the system 222, as is a

power supply 238 which may be used to back-up a main power supply of the vehicle in which the system 222 is fitted.

In the event of an accident, the strap is automatically locked by way of the solenoid 230 and relays 232 in response to the sensor 234 sensing an impact or inversion of the vehicle. The budget safety system 222 has no drive system for driving the inertia reel 226, thus the strap is locked but not retracted, in contrast to the system 10 described above with reference to Figures 1 to 9. A recovery crew is able to detach the backboard 224 from the seat at the hinge 229 (which may have a quick-release mechanism), and remove the backboard 224 with the driver. Advantageously, the budget safety system 222 is able to be fitted to an existing driver's seat, so as to avail the system to people (eg. amateur racing car drivers) who may not be able to afford a full system as shown in Figures 1 to 9.

Figure 17 shows a switch mechanism 240 for activation by a sensor arrangement such as the sensor arrangement 150 shown in Figures 10a and 10b. As the sensor arrangement 150 provides only a very brief pulse in the event of an impact, and the panic button (manual override) may only provide a brief pulse in the event it is operated, the applicant has developed the switch mechanism 240 which switches in response to a pulse from the sensor arrangement 150 and/or the panic button so as to operate the restraining mechanism.

The switch mechanism 240 includes a steel actuator 242 which is pivotally mounted to be movable between a first condition in which the steel actuator 242 forms an electrical connection between a pair of contacts 244, 246, and a second condition in which the contacts 244, 246 are separated such that there is no electrical connection. When in the first condition (as shown in Figure 17), electricity fed from a supply switch to input lead 248 is transmitted via the contacts 244, 246 and output lead 250 to a motor for operating the inertia reel.

A pair of electro-magnets 252, 254 are provided for moving the steel actuator 242 between the first and second conditions by selectively attracting the steel actuator 242.

One electro-magnet 252 is connected via lead 256 for operation by the sensor arrangement and/or panic button (manual override) so as to bring the steel actuator 242 to the first condition, and the other electro-magnet 254 is connected via lead 258 for operation by a reset switch so as to bring the steel actuator 242 to the second condition. Accordingly, the switch mechanism 240 will supply power to the output lead 250 until the reset switch is operated. An opposite terminal of each of the electro-magnets 252, 254 is connected to a supply lead 260. A tension spring 262 biases the steel actuator 242 to prevent it from moving under its own weight.

In a variation of the invention, a safety system for a regular road car has a sensor for sensing an impact, and a device for operating a reel of a seatbelt to tension the seatbelt in response to the sensor sensing a predetermined event. The sensor may be the same as or similar to the sensor arrangement 150 shown in Figures 10a and 10b, and the device for operating the reel may be the same as or similar to the arrangement shown in Figures 5 a and 5b.

The above safety system for a regular road car has the following advantages:

• It can react to force from any direction, inversion and high gravitational load.

• Under load the reel will simply lock before a normal inertia reel can. • A normal inertia reel requires the belt to run on before it can lock where the above safety system does not.

• As run on is effectively eliminated this reduces the need and effectiveness of a pretensioner.

• A pyrotechnic pretensioner needs to be replaced after an accident, whereas the safety system is able to be simply reset.

• The safety system is able to be arranged to also deploy any or all air bags in a vehicle and has the potential to determine direction and strength of the force and react accordingly.

• The safety system presents no risk to emergency crews as un-deployed pyrotechnics do.

• The safety system can determine if air bags are required or not.

• The safety system can also be installed with an independent power system to ensure full operation during an accident.

Figure 18a shows a reusable air bag 276 which may be activated by operation of a sensor as described above. The reusable air bag 276 has a pyrotechnic charge 278 for inflation of the air bag 276, the pyrotechnic charge 278 being adapted for electrical coupling to the sensor, and a pressure relief valve 280 for deflation of the air bag 276. The pyrotechnic charge 278 is removably attached to the air bag 276 by way of mating threads on the air bag 276 and the pyrotechnic charge 278 such that the pyrotechnic charge 278 can be removed and replaced with a fresh charge once it is used. Figure 18b shows an enlarged view of the pyrotechnic charge 278, and Figure 18c shows an enlarged view of the 280 pressure relief valve. The cross-sectional view of the air bag 276 in Figure 18d shows where side membranes of the air bag 276 are attached, for example by way of welding or adhesion. The air bag 276 itself may be formed of reinforced latex material.

The air bag 276 can be manufactured in any shape or size to suit different vehicles, and can be configured to be activated in response to operation of a sensor as described above, in a set of specific circumstances which may not necessarily be identical to the set of circumstances under which other components of the safety system are activated.

Figure 19 shows an example of an ignition/fuel pump shut down assembly 282 for operation in response to activation of the sensor and/or the manual override of a safety system as described above. The ignition/fuel pump shut down assembly 282 includes a first (changeover) relay 284, and a second (5 -pin) relay 286, a solenoid 288, a rotary activator 290, and an isolation switch 292. The first relay 284 receives an impulse from the sensor and turns off the ignition of the vehicle, then sends an impulse to the second relay 286 which activates the solenoid 288. The solenoid 288 switches off the isolation switch 292, which in turn shuts down a fuel pump of the vehicle.

A modified inversion sensor 294 is shown in Figure 20, and includes a ball bearing

296, a rubber stopper 298 and a microswitch 300 which is activated in response to travel of

the ball bearing 296 in the case of inversion of the vehicle. A housing 302 in which the ball bearing 296 travels is inclined at 30 degrees such that rotation of the vehicle about a vertical axis through the vehicle's centre of gravity will serve to assist operation of the sensor 294, provided the sensor 294 is mounted at a location of the vehicle spaced from the centre of gravity and with the angled housing 302 directed away from the centre of gravity. This can be achieved by mounting the modified inversion sensor 294 at an outward side of the driver of the vehicle. It is intended that the modified inversion sensor 294 is used in conjunction with the sensor shown in Figure 10b, to compensate for the potential inability of that sensor to sense inversion in the presence of large centrifugal forces.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Throughout this specification, unless the context requires otherwise, the word

"comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated step or integer or group of steps or integers but not the exclusion of any other step or integer or group of steps or integers.