VEHICLE SAFETY SYSTEM

Abstract: A vehicle safety system for restricting the movement of a vehicle occupant's head relative to the vehicle in cases of extreme acceleration or retardation as a result of a collision or similar, comprising a net (12) or similar which on release can rapidly be deployed in front of the vehicle occupant's head, wherein the device is in the form of a headrest, the net (12) is stowed in a net compartment (27) in the headrest and the net can be drawn out of the net compartment (27) and to a position forward of the vehicle occupant's head by arms (3, 4) which can be swivelled out of the device by means of a pretensioned elastic body (25).

Description: VEHICLESAFETYSYSTEM The present invention relates to a vehicle safety system, in particular a safety system which protects against whiplash injuries. Motoring injuries are a major and growing problem with today's ever-increasing traffic. Whiplash injuries seem to be on the increase more than other types of motoring injuries, which may be due to the extensive use of car seat belts. In a collision from behind, the car and thus the car occupant's body, experiences an increase in speed forward, whilst the head continues at the same speed. The effect of this is that the head is flung against the headrest which only in exceptional cases is in contact with the head when driving is in progress, whereupon a first injury occurs due to the head being flung back in this way. The occupant's head is then thrown forward whilst the upper part of the body is restrained by the seat belt. Thus, the neck is subjected to a sudden flexural stress which may result in another injury in the neck region. These whiplash injuries are a major problem both for the individual and for society. The individual suffers a lot of pain and often loss or reduction of capacity to work. For society, this causes loss as an additional strain on the health service and loss of earnings. For the insurance companies, whiplash injuries mean enormous losses in the form of compensation and so forth. Despite intense research into car safety and the introduction of safety belts and airbags, no equipment has been developed for the prevention of whiplash injuries. Airbags have gradually become quite common, especially in new cars, but this equipment does not provide adequate protection against whiplash injuries. Certain other vehicle safety systems have also been developed, which for various reasons have not become common in cars, for example, US Patent 4,909,459 teaches a helmet-mounted head restraint, intended preferably for use in aeroplanes. The device is rather unsuitable for a car as there are few people who drive wearing a helmet. Moreover, certain systems involving inflatable devices are known. For example, US Patent 3,779,577 teaches an installation having two airbags, one in front and one behind the headrest of the front seat, which in the event of a collision are inflated and are able to protect the driver's head from injurious impact against the headrest, and can also prevent a back-seat passenger from injuring himself on the back of the front seat. US Patent 3,753,576 and US Patent 3,953,049 both teach hoop devices for supporting and/or conveying an inflatable member which according to need is triggered by a sensor, is inflated and prevents the vehicle occupant's body and/or head from being flung forward. Solutions are also known where shields, nets or similar which in normal conditions are positioned above the head of the driver and/or passengers, and which upon collision are actuated, pulled down in front of the person and embrace the head and upper part of the person's body. Of the devices of this type mention can be made of US Patent 5,226,672, where a net, which is normally stowed in the vehicle roof above and forward of the person's head, in the event of a collision is drawn down and back by a number of cables which are pulled by suitable quick-action drive mechanisms. DE 2601314 Al , DE 3636040 A 1 and US Patent 3692327 all teach devices where hoops with a shield, respectively a net, are extended down in front of the head and upper part of the vehicle occupant's body in the event of a collision. Common to all these hoop-based systems is that the devices are large and bulky, and difficult to incorporate in an acceptable manner into a vehicle, especially when mounted subsequent to the vehicle being built. Common to all these known devices is that they require sizeable installations and are difficult to build into a new car or in particular to mount in a used car in a manner that is acceptable to the users. The objective of the present invention is thus to provide a car safety system which upon collision from behind will prevent or reduce neck injuries whilst being acceptable to the user both when it is in stored pre-operative position and also after it has been released, and furthermore that the device can be mounted in new and used cars in an acceptable manner. This problem has been solved by means of a vehicle safety system for restricting the movement of a person's head relative to a vehicle on extreme acceleration or retardation as a result of a crash impact from behind or similar, comprising a net or similar which when released is rapidly deployed in front of the person's head, where the device has the form of a headrest, the net is stowed in a net compartment in the headrest and can be drawn out of the net compartment and into a position forward of the person's head by arms operated by a pretensioned elastic body. The device according to the present invention is not intended to be a replacement for the seat belt, but a supplement thereto. The seat belt ensures that in the event of a collision the body is not thrown forward in the car, whilst having little or no effect in terms of restraining the head. The device according to the present invention will, however, restrain the head so that the combined effect of the use of a seat belt and the present device will be that both the body and the head are prevented from being thrown forward on collision, thereby also avoiding or effectively preventing neck injuries which occur in association with the head being thrown forward. The present invention will now be described with reference to the accompanying figures, wherein: Figure 1 is a side view of a preferred embodiment of the device through section B in Figure 2.. Figure 2 is a front view of the present device with the front partly removed. Figure 3 is a side view of the device when released. Figure 4 is a partial cutaway side view of a second embodiment. Figure 5 is a front view of the same embodiment as in Figure 4, where some of the covering elements have been removed. Figure 6 is a partial cutaway plan view of the device according to Figure 5. Figure 7 shows a device according to the present invention secured to a chair back for use in connection with a child seat. Figure 8 is a partial cutaway front view of a third embodiment of the present invention. Figure 9 shows a section along the line A-A on Figure 8. Figure 10 shows a section along the line B-B on Figure 8. Figure 11 is a side view of the embodiment from Figure 8 in released positioned. Figure 12 shows a section of the locking mechanism illustrated in Figure 8. The device illustrated in Figures 1 to 3 is a first preferred embodiment of the present invention and Figure 1 is a side view of a preferred device according to the invention in stowed, pre-operative position. The outside of the device is covered by a cover 1 and is preferably padded with non-illustrated padding, so that the device will be suitable and comfortable as a headrest. The headrest can be secured in the headrest mount in the seat back by means of a fixing device 2 secured to the basic body 33 of the headrest. The basic body of the headrest 33 is affixed to an attachment section 34 which is a section for securing a number of the device components by means of screws 23. The angle of the headrest relative to the seat back on which it is mounted can be adjusted by means of the screws 23 and groove 24 in the basic body 33. Arm 3,4 is pivotally mounted on the basic body 33, in that the arm 3,4 is secured to drum 21 which is rotatable with little friction against the basic body 33. Spring 25 lies around the drum 21 and is secured to the basic body in the spring retainer 35. Spring 25 is secured to drum 21 and to spring retainer 36. ln a normal position as shown in Figure 1 spring 25 is tensioned, but arm 3,4 is prevented from swinging forward by a locking device which will be described in more detail below. In order to render the present device acceptable to the majority of users, i.e., that the headrest is at an acceptable height from the seat back and that the device nevertheless is effective in ensuring that the net is in fact brought down over the seat occupant's head, it is preferable that arm 3,4 is telescopically extendible as shown in the accompanying figures. In the principal embodiments, arm 3,4 consists of an outer arm 3 by which there runs an inner arm 4. When the device is triggered, the inner arm 4 is pulled outwards by means of an elastic cord 7 which runs from a static attachment 5 on the outer arm 3 over a roll 8 on the other end of the outer arm 3 and down to attachment 6 on the inner arm 4. The attachment 6 runs in groove 32 in the outer arm 3. The present safety device has two such arms 3,4 as described above, one on each side of the headrest. The two arms are connected by shaft 29 which connects the drums 21 on both sides of the headrest. The shaft 29 is secured to sleeve 31 on the drums 21 by means of a screw. Sleeve 31 turns with little friction against the basic body in slide bearing 28. Moreover, the arms 3,4 in the upper end thereof are connected to net holder 26. Net holder 26 may be a rigid rod or preferably of a more flexible material which will not injure a person's head if the device is released in error or the head is in the wrong position at the instant of release. The purpose of the net holder 26 is to pull the net 12 forward when the device is released. In this preferred embodiment, the locking device comprises an inertia device having release bar 16 which runs transverse to the headrest, transverse to which a bar 18 and a release bar 37 are secured. Roll 15 on the release bar 37 rests against pin 14 on the outer arm 3 and prevents the arm 3,4 from swinging forward. A weight 17 is secured to the release shaft 16 in such manner that on rapid acceleration/retardation it swings forward respectively backwards, turns the release shaft 16 and thus also release bar 37. If the turning of the release shaft 16 due to the speed change is sufficient for roll 15 to disengage from the pin 14, the device is released. Spring 19, which is secured to attachment section 34 and to bar 18, and the inertia in turning the release shaft 16 and the release bar 37 are decisive for the retardation/acceleration on which the present device is to be released. When the device is in the stowed, pre-operative position, i.e., tensioned and ready for release, the telescopic extension of the inner arm 3 is prevented in that roll 1 1 rests against the outer wall 1 of the device. When the device is triggered, i.e., the locking is released by means of the locking device as described above, arm 3,4 swings forward driven by springs 25, one for each arm. When arm 3,4 is swung forward, roll 1 1 disengages with the cover 1 at a given angle, on Figure 1 indicated as angle α. On the release of this telescopic arm, arm 3,4 is first brought forward through the given angle α so that roll 11 disengages from the outer wall. At this angle roll 10 also rests against inclined plane 9. The purpose of this is that the inner arm 4 is to be extracted to a certain length, corresponding to the length of the inclined plane 9 before the arm 3,4 is swung further forward in order to ensure that net holder 38 is in fact above the head of the seat occupant. The arms 3,4 swing until they either rest against the shoulders/chest of the occupant of the seat furnished with the headrest, or have swung to a predetermined angle. The net 12 is drawn forward from the net holder 26. The net 12 is also firmly suspended from the headrest in one or more net attachments 20 and in two hoops 13. In this way the net is swung over the head of the seat occupant and ensures that the head is restrained. The hoops 13 which are secured to the attachment section 37 ensure that the net 12 can be folded together when the device is in the pre-operative position, whilst ensuring that the net 12 comes into position in the best possible way when the device is released. Figure 3 shows the device as shown in Figures 1 and 2 in released state, and shows clearly how a person's head is restrained by the net. The net, which preferably is a net as illustrated, may be made of a more or less elastic material. It is however preferable that the material is not highly elastic as this will allow the head to be pulled forward. The material must, however, be so flexible that it falls around the head in a soft and agreeable fashion. Once the device has been released, the inner arm 4 can again be pushed into the outer arm 3, and retracted, and the device can be locked. The device is then ready for use once again. Figures 4 to 7 show an alternative and also preferred embodiment of the present device. In contrast to the first illustrated device, this is adapted to be clamped onto a vehicle seat back by means of a clamping plate 41 having straps 47 and buckle 42. This device may, for example, be used for securing a child in a child seat 45, where the child sits in a child seat 45 secured with the car's regular seat belt. 44. This alternative embodiment also has a locking mechanism which is of a mechanical inertia release form having the same mode of operation as the other, but with a somewhat different construction. Figure 5 is a front view of the embodiment in Figure 4 and Figure 6 is a plan view thereof. In this embodiment all the inner parts of the device, apart from shaft 29, release shaft 16 and net compartment 27, are located in side cushions 47. This embodiment can be secured to the seat back in another way than that shown in Figure 7, by means of attachment eye 39 or fixing bracket 40. As shown in section in Figure 4, the net compartment 27 may be equipped with a separate cover 38. Figure 7 shows a headrest according to the present invention positioned in connection with another seat. In this embodiment, the present device is secured by means of straps to the car seat back 46, and is not secured to the seat back mount for headrest attachments as disclosed above. Mounted as shown in this figure, the back 48 of the child seat is forward of the release shaft 16 and shaft 29 so that the headrest on the child seat back 48 supports the child's head. It may therefore be preferable for the distance between the cushions 47 to be adjustable by means of a form of telescopic extension of shaft 29, release shaft 16 and net compartment 27. The height of the position of the present device can be adjusted by conventional adjustment of the back length of the child seat. The device shown in Figures 8 to 12 is a third preferred embodiment of the present invention. Like the previously described embodiments, this embodiment has two arms, one on each side of the device. Both arms and the means around these are constructed in the same way on both sides. In contrast to the above-described embodiments, the arms 50 in this embodiment are made of a flexible material. When the device is tensioned, the arms 50 are rolled up around a hub 54 and are guided by a plurality of guide rolls or pins 57. The arms 50 in this embodiment can be made of an elastic material so that they themselves form a spring such that on release they are thrust out by their own spring force. They may be thrust out by a separate spring 58 or a combination of their own spring force and a separate spring 58. The hubs 54 on each side are connected by means of a shaft 56 which runs transverse to the device. This shaft 56, which in the illustrated embodiment is surrounded by a sleeve 62, ensures simultaneous and identical release of both arms 50. The sleeve 62 is fixed relative to the basic body 60 of the device, and an optional elastic body, for example, in the form of a spring 58, may be located between the shaft 56 and a spring retainer 59 which is mounted on the sleeve 62. In the embodiment shown in the figures, an inertia released locking means 61, which will be described in detail below is located along the shaft 56 and locks this. This locking device 61, together with the elastic body 58 in the form of a rotary spring, is shown in greater detail in Figure 12. When the device is triggered, the locking of the locking means 61 is released and hub 54 is rotated by means of the spring force in the arms 50 and/or spring 58. As a result of this rotation of hub 54, the arms 50 are rolled by the hub 54 and thrust out of the device with a ball 52 first. A cord 51 which is also rolled up on the hub 54 and which is secured to the ball 52 is also drawn out with the arm 50. Cord 51 is however secured to the hub 54 in such a way that a certain roll-out length is rolled in again. By virtue of the fact that the arm 50 lies above the uppermost of the rolls 57 and cord 51 lies below this uppermost roll 57, the arm 50 is thus pulled downwards and forward of the person's head as shown on Figure 1 1. As in the other embodiments, a net holder 53 is located between the balls 52 on the arms 50. The net holder 53 is preferably of a flexible material and can, when loaded in a certain way, be pulled free of the arms 50 thereby avoiding an unfortunate/unpleasant point loading on the upper part of the person's body. The net 12 is stowed in a net compartment 63 and the rear portion of the net 12 is secured here by non-illustrated net attachments. At the front edge the net is secured to the net holder 53 and along the sides the net is partially secured to the arms 50 by means of rings 64 which on release can slide along the arms 50. The last illustrated embodiment is also made for stepwise adjustment of the angle of the headrest and thus also its distance from the person's head during normal use. Figure 10 shows a section along the line B-B in Figure 8 and here shows clearly adjustment disc 65 with teeth 66 in which a cam 69 on a spring-loaded arm 67 which is pivotally mounted on the basic body 60, can engage and retain a desired position. The locking means 61 which is shown in Figure 12 is, as in the case of the preferred embodiments, an inertia device. The tensioned spring 58 is locked in that cam 77 on the release shaft 56 against which spring 58 rests is retained by locking roll 76 on locking arm 74. Locking arm 74 is pivotally mounted in shaft 75 and its tip 79 rests against locking pin 80 on weight arm 71. Weight arm 71 is rotatable about an axis 72. A weight 70 located on weight arm 71 will on great change of speed swing out so that locking pin 80 is pulled out of engagement with the tip of the locking arm 79. The locking arm will then be pulled by spring 78 so that locking roll 76 is drawn out of engagement with pin 77. The spring 58 will then turn the release arm 56 and the arms 50 will be thrust out. The mesh of the net can vary over large areas. Thus, if so desired, a relatively dense net having a very small mesh can be used in some cases, whilst in other cases it will be natural to use a relatively coarse net. Thus, it is conceivable to use everything from coarse-meshed net via relatively densely woven material to perforated films. A relatively coarse-meshed net is, however, preferred. By using a relatively coarse- meshed net, the net itself after release will not obstruct the driver's view. This may be important if the net is released in error. If the mesh is too large, the net will feel unpleasant because of the relatively large point loading at the places where the net rests against the head. Thus, there is no set answer to what the most desirable mesh is, but it can vary greatly without having any major effect on the inventive idea. The locking means for the arms 3,4, 61 may also have an entirely different design than that shown. Other mechanical inertia means are conceivable, as are electronically controlled devices analogous with those used for airbags in cars. Moreover, it is possible for the locking means to be coupled to the car's electronics, in order to obtain release of the device when this is desirable for various reasons. In the case of an electronically controlled locking means, it can also be ensured that only the devices on occupied seats are released, and also that the release of some of the devices in a vehicle can be locked if for some reason or another it is not desirable that on collision the device should be released. The device is moreover described mounted in a headrest, but can of course also be built into the vehicle seat back in seats where the headrest is an integral part of the seat back.

Claims: P a t e n t c l a i m s 1. A vehicle safety system for restricting the movement of a vehicle occupant's head relative to the vehicle in cases of extreme acceleration or retardation as a result of a collision from behind or similar, comprising a net (12) or similar which on release can rapidly be deployed in front of the vehicle occupant's head, characterised in that the device is in the form of a headrest, that the net (12) is stowed in a net compartment (27,63) in the headrest and that the net can be drawn out of the net compartment (27,63) and into a position forward of the vehicle occupant's head by arms (3,4,50) which can be swivelled out of the device by means of a pretensioned elastic body (25,58). 2. A safety system according to Claim 1, characterised in that the elastic body (25) is a spring. 3. A safety system according to Claim 1 or 2, characterised in that the arms (3,4) are telescopically extendible. 4. A safety system according to Claim 3, characterised in that the arms (3,4) on release of the device are prevented from swinging forward before they have been telescopically extended to a predetermined length. 5. A safety system according to Claim 1 or 2, characterised in that the arms (50) are of a flexible material which, when the device is tensioned, is partially rolled up around a hub (54). 6. A safety system according to Claim 5, characterised in that the arms (50) are of a resilient material. 7. A safety device according to Claim 5 or 6, characterised in that the arms (50) are pulled down towards the upper part of the vehicle occupant's body by means of cords (51) attached to the forward ends of the arms (50). 8. A safety system according to one or more of the preceding claims, characterised in that the arms (3,4) can be locked in the tensioned position by means of an inertia-controlled lock device.

Inventors: KALLEBERG JACOB, KALLEBERG, JACOB
Applicants: KALLEBERG JACOB, KALLEBERG, JACOB
Application year: 1996
Main classification: B60N2
IPC codes: B60N2, B60R21