WO1997035741A1

WO1997035741A1 - A seat device for a motor vehicle

Info

Publication number: WO1997035741A1
Application number: PCT/SE1997/000555
Authority: WO
Inventors: Karlo Smit; Janos Kovacs
Original assignee: Karlo Smit; Janos Kovacs
Priority date: 1996-03-27
Filing date: 1997-03-27
Publication date: 1997-10-02
Also published as: AU2315697A; SE9601183L; SE9601183D0

Abstract

A seat device for a motor vehicle comprises a seat bottom (2), a back support (1) and a head support (3). The back support and the head support are arranged to provide support of the head, the neck and the back portion of a user sitting in the seat device. The back support (1) has an angle of inclination which may be adjustable or fixed. The seat device comprises means (10, 11) which, at a violent vehicle accident, such as a rear-end collision but also secondarily after a frontal collision, during which the head, the neck and the back portion are rearwardly accelerated, and irrespective of the angle of inclination (O-U) of the back support (1), are arranged to provide the movement of the back support (1) to such a first safety position (N) that simultaneity of the retardation of said acceleration of the head, the neck and the back portion is essentially obtained.

Description

A seat device for a motor vehicle

THE BACK GROUND OF THE INVENTION AND PRIOR ART

The present invention refers to a seat device for a motor vehicle, comprising a seat bottom and a back support, arranged to provide support for the head, the neck and the back portion of a user sitting in the seat device, the back support having a first angle of inclination in relation to the normal travel direction of the vehicle.

The traffic intensity increases substantially in the world and together therewith the number of collisions of the type "rear-end collision", i.e. the front of a vehicle collides with the rear portion of another vehicle. Such collisions frequently causes so called whiplash injuries (or WAD = Whiplash Associated Disorders). It is to be noted that such injuries also may appear at other types of collisions than rear-end collisions. Whiplash injuries may appear already at relatively slow collision velocities and women are more subjected thereto than men, at least partly due to the fact that they have a less strong neck musculature.

The symptoms of injuries which appear in connection with whiplash injuries comprises pain, weakness or abnormal response in the parts of the body (mainly the neck, the shoulders and the upper back) which are in contact with the central nervous system via the cervical nerve roots. Today, medical scientists know to little about this type of injuries, how a whiplash injury arise and what it really is.

From own studies it has appeared that the most frequent type of whiplash injuries are stretching injuries of different degrees on the cervical nerve roots close to the spinal channel. Such stretching injuries may mainly arise at a certain angle deviation of the head/cervical spine in relation to the upper part of the body/the chest in connection with quick extension-flexion movements in the cervical spine at a collision and in particular in combination with acceleration differences between the head and the upper part of the body/the chest. Many different attempts have been made in order to reduce the whiplash injuries frequently appearing at collisions but up to now without any greater success.

Among other things one has tried to solve the problems with whiplash injuries by so called active neck protectors. These may be of different types such as neck supports, head supports or back supports in combination with neck supports and head supports. In normal cases, such supports are at a rear-end collision rotated forwardly upwardly or possibly first forwardly upwardly and thereafter rearwardly. One problem with these known devices are that they always rotate equally in completely uncontrolled manners irrespective of which driving or sitting position the driving persons have at a collision. The course of accident in connection with such known active neck protectors is now to be explained with reference to Fig 1 and 2. In Fig 1 the driving person has a rearwardly inclined driving position and at a rear-end collision the rotation forwardly of the neck protector will not be sufficient for retarding the rearward movement of the head at an early stage. Thus, the retardation of the reward movement of the head in relation to the body will be significantly delayed and this probably results in serious neck injuries. In Fig 2, which discloses the same active neck protector as Fig 1 , the driving person has a somewhat more upright adjustment of the back support than in Fig 1 , the head resting against the head support. At a rear-end collision the head support will rotate forwardly in a completely uncontrolled manner, which leads to the consequence that the head is forced more or less forwardly by a large force at the same time as the body continue its movement rearwardly. In the case disclosed the acceleration difference between the head and the body and thereby also the frequency of injuries would probably been significantly less if the actual driving person instead of an active neck protector would have had a usual vehicle seat having a real head support of conventional type. In addition, for both the adjustments which are disclosed in Fig 1 and 2 it is valid that when the rearward movement is completed the back support is located in its most rearward position powerfully forced by the rearwardly throwing driving person. Due to the elastic properties of the back support it will therefore throw the body forwardly by a large force into the safety belt, the head continuing forwardly by undiminished speed with risk for serious neck injuries.

Furthermore, it is known that by an active neck protector of the type disclosed herein the throwing forwardly of the body may be prevented by firstly displacing rearwardly the whole back support together with the head support by a certain tilting movement and thereafter bringing the back support further rearwardly by means of friction braking or the like. Thereby, it is known to provide such a rearward tilting by means of a friction brake positioned at a lower part of the back support. However, the problem with this solution is that the elastic properties of the back support are essentially maintained also after such a friction braking, especially at an upper part of the back support, which at a rear-end collision is most elastically rearwardly bent and thereafter consequently will throw the head forwardly in the same way as by previous known back supports. Such a completely uncontrolled manner of tilting the back support may by a great probability even cause significantly more serious whiplash or neck turn injuries, especially at the final phase of the back support tilting (the so called abrupt stop) than the injuries which would have arisen due to the throwing forwardly proper at the same time as the risk is also significantly increased that the body will be lifted out of the seat and thrown rearwardly out through the rear window at a so called "ramping" accident (overtaking accident at a very high speed), especially if the driving person already from the beginning has a rearwardly inclined driving position, as is illustrated in Fig 1.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a safety seat offering the user an improved protection against injuries especially at rear-end collisions but also secondarily after a frontal collision. In particular, it is aimed at a safety seat by which the risk for whiplash injuries may be reduced. A further purpose of the invention is that the safety seat is to offer an individually adapted permanent protection and thus reduce the risk of injuries irrespective of the weight, the length, the sex etc. of the driving person.

This purpose is obtained by the seat device initially defined and characterized by first means which, at a violent vehicle accident, such as a rear-end collision but also secondarily after a frontal collision, during which the head, the neck and the back portion is rearwardly accelerated, and irrespective of the first angle of inclination of the back support, are arranged to arranged to provide the movement of the back support to such a first safety position that simultaneity of the retardation of said acceleration of the head, the neck and the back portion is essentially obtained. Such a simultaneity of the retardation of the body parts of the driving person is particularly important for avoiding whiplash injuries. The simultaneity means that the whole body of the driving person, i.e. both the head and the upper part of the body, is given a support uniformly distributed along the backbone. By such a safety position, it is achieved that one may prevent the two uppermost cervical vertebrae, atlas and axis, at a collision from being locked or fixed in a certain position of rotation in relation to each other. Without such a fixation or blocking of the cervical vertebrae, the head may still maintain its normal capability of rotational movements at a collision and in such a manner the risk of skeleton, nerve or muscle injuries in the neck back is eliminated. Advantageously, the first safety position thereby comprises a protective angle of inclination of the back support, which may be predetermined or adaptable to different situations. One such protective angle of inclination, for obtaining the best possible result, may for instance be determined individually for each type of car at laboratory tests based on the body constitution of a normal person having a weight of 75 kg and a length of 175 cm. In such a protective angle of inclination may also a part, for example 50% of the total expected angle deviation, i.e. the downward bending of the back support from an initial position at a rear-end collision at low speed. Advantageously, the first safety position of the back support comprises a protective angle of inclination automatically adapted to different collision situations or different individuals i.e. different body constitutions. Such an optimal protective angle of inclination of the back support may be determined by means of different sensing means mounted in the seat bottom and the back support in order to calculate the weight and length of the driving persons. The information may then be transferred to a back support locking mechanism controlled via collision data. This back support locking mechanism may also have such a function that it is able to lock the back support in the direction of acceleration caused by the collisions at a collision obliquely from behind and/or obliquely from the front. By such an embodiment one may effectively eliminate the risk of neck injuries to a very large extent essentially irrespective of the angle of collision, except at rear-end collisions also at frontal collisions where the most disabling whiplash injuries actually are registered. Advantageously, the seat device is in this case provided with a four-point-belt of suitable type or with a three-point-belt in combination with an additional diagonal belt with a reel.

According to one embodiment of the invention displacement members are arranged, after the back support as taken said first safety position, to provide a rearward displacement of the back support when the body has completed its rearward movement. Advantageously, this rearward displacement is performed while maintaining said protective angle of inclination. In this manner the body is effectively prevented from being thrown forwardly after a collision due to the inherent elasticity of the back support (rebound effect) at the same time as the body may maintain its whiplash injury free position also under and after the rearward displacement. Said displacement members are advantageously arranged in such a manner that the back support is released only when the body definitively has completed its movement rearwardly, i.e. completely irrespective of which loading force the back support is subjected to at a collision.

According to a further embodiment of the invention, the first angle of inclination of the back support is adjustable, which enables each individual to find an comfortable proper driving position, or fixed in a position comfortable for the user, such as for example normally is the case in the rear seat.

According to a further embodiment of the invention, the first means, at said violent vehicle accident are arranged to utilise the kinetic energy of the user accelerated rearwardly in order to provide the force necessary to bring the back support to said first safety position.

According to a further embodiment of the invention, the first means comprises a reading device arranged to sense the first angle of inclination of the back support. By means of such a reading device the actual angle of inclination of the back support may be determined and it is thereby possible to determine the distance necessary for returning the back support to the first safety position. Thereby, the first means may also comprise a locking mechanism arranged to enable the movement of the back support from the read angle of inclination to said safety position and to block the back support in this position. The locking mechanism may comprise a reel onto which a wire member is wound and the locking mechanism may be arranged to cooperate with the reading device. The reading device and the locking mechanism may also according to a simple embodiment comprise a blocking piece, possibly adaptable for different types of vehicles, for instance a kind of angle bar iron, by means of which the back support at a collision will be brought to an angle of inclination determined by the blocking piece irrespective of the adjusted angle of inclination. To enable the back support to be tiltable forwardly to a maximum degree without any hinder, the blocking piece may be provided with an automatic engagement and disengagement. The blocking piece may also be shaped as a stop projection or the like being fixedly provided in the vehicle, in particular for the rear seats, which determines the protective angle of inclination of the back support and a stop projection or the like which determines the size of the displacement rearwardly.

According to a further embodiment of the invention, the back support comprises an outer frame member and an inner frame member comprising a back support member and being pivotably mounted to the outer frame member. Furthermore, the seat bottom may comprise a seat plate displaceably provided in the seat bottom and being journalled to the inner frame member. Thereby, blocking members may during normal use be arranged to lock the inner frame member in a fixed position in relation to the outer frame member and at said violent vehicle accident to release the inner frame member in relation to the outer frame member.

According to a further embodiment of the invention, the seat device comprises a head support provided on the back support, at least one of the head support and the back support being prolongable upwardly in a direction away from the seat bottom. In such a manner one may provide a safety adjustment for individuals having different length of the body essentially between 140 and 200 cm. Thereby, the head support may advantageously comprise a number of sections which during adjustment come apart and are moved upwardly with essentially the same distance increase between all sections. It is also possible to provide an energy storage member which at said violent vehicle accident is arranged to release a force providing said prolongation by an increase of the distance between adjacent sections. A certain height adjustment may also be obtained due to the fact that the back support proper is prolongable.

According to a further embodiment of the invention the back support comprises a holding-up member and a support element provided in front of the holding-up member, i.e. facing the user, and being arranged to take a shape individually adapted to the user. Thereby, the support element comprises a number of cells arranged to take a shape adapted to the user by discharge of gas contained in the cells. By such a construction of the support element, this may be given a completely individually adapted shape which at the same time is very stable and provides a safe protection at a collision or the like. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is now to be explained more closely by means of different embodiments disclosed merely by way of example and with reference to the drawings attached.

Fig 1 and 2 discloses how whiplash injuries arise during use of known so called "active neck protectors". Fig 3A and 3B discloses the function of the seat according to the invention at two different possible course of accident. Fig 4 discloses in a sideview the seat device according to the invention in different positions. Fig 5 discloses in a sideview how a user is moved in the seat device according to the invention at a collision. Fig 6 discloses a partly sectional front view of the back support of the seat device according to the invention.

Fig 7 discloses a sectional view from above of the back support of the seat device according to the invention. Fig 8 discloses a partly sectional view of the seat bottom of the seat device according to the invention. Fig 9 discloses a partly sectional sideview of a reading device and a locking mechanism of the seat device according to the invention. Fig 10 discloses a partly sectional sideview of a reading device and a locking mechanism according to a second embodiment Fig 11 discloses a front view of a warning device for the seat device according to the invention. Fig 12 discloses a partly sectional front view of a seat device according to a further embodiment of the invention. Fig 13A-D discloses the seat device in Fig 12 in different positions.

DETAILED DESCRIPTION OF DIFFERENT EMBODIMENTS

In Fig 3A is illustrated how a back support, which is adjusted into a very rearwardly inclined position U, together with the head support are reset at a rear-end collision where the risk of whiplash injuries exists, from the angle of inclination U to a predetermined protective angle of inclination N, where one always may obtain a simultaneity in the retardation of the rearward movement t1' of the head and the rearward movement t1 of the body. As is to be described below, the back support is shaped in such a manner that it, from all adjusted angles of inclination between the angles N and U will be moved p-a to the protective angle of inclination N at a violent vehicle accident, such as a rear-end collision or secondarily after a frontal collision.

In Fig 3B is illustrated how a back support, which is adjusted into a very forwardly inclined position O, together with the head support are reset at a rear-end collision from the angle of inclination O to the previously mentioned protective angle of inclination N, in order to in this manner also in this case provide a simultaneity in the retardation of the rearward movement t1' of the head and the rearward movement t1 of the body. Also in this case the back support will thus at such a mentioned vehicle accident always take the protective angle of inclination N irrespective of the adjustment of the back support between the angles of inclination O and U prior to the violent vehicle accident.

In order to prevent the body from being thrown forwardly after it has completed its rearward movement, the whole back support is slacked in a controlled manner, i.e. the back support and the head support is moved rearwardly to the position S at which the back support and the head support still take the protective angle of inclination N, as is disclosed in Fig 3A and 3B. The technical construction of the different embodiments of the present invention is now to be explained more closely with reference to the figures. It is to be noted that for the components having a corresponding function the same reference signs have been used in all embodiments.

Fig 4 - 9 discloses a seat device according to an embodiment of the invention. Fig 4 and 5 illustrate in a similar manner as Fig 3A and 3B how the back support is reset to the protective angle of inclination N from different adjusted positions. The seat device comprises a back support 1 , a seat bottom 2 and a head support 3. The back support 1 comprises an outer frame member 4 and an inner frame member 5. The inner frame member 5 has two pin-like members 6 which are provided in alignment with each other on a respective side of the inner frame member 4. The pin-like members 6 which are fixedly attached to the inner frame member 5 extends through a respective groove-like recess 7 in the outer frame member 4. Each pin-like member 6 is loosely provided in a groove¬ like recess 7 in such a manner that the inner frame member 5 may be pivoted about the pin-like members 6 and displaced in the longitudinal direction of the groove-like recesses 7 extending essentially vertically when the back support 1 is in the protective angle of inclination N. The pin-like members 6 are located at about the middle of the inner frame member 5. It is to be noted that in principle it is possible to provide the pin member 6 on the outer frame member 4 and the groove-like recess 7 in the inner frame member 5. The seat bottom 2 comprises a relatively stiff seat plate 8 which is displaceably provided in the seat bottom 2 and journalled to the inner frame member 5. Therefore, the seat plate 8 will be displaced rearwardly when the inner frame member 5 is tilted upwardly from the angle of inclination U to the protective angle of inclination N, see Fig 5. Fig 4 and 5 disclose schematically an adjustment mechanism 9 by which the back support 1 , i.e. the outer frame member 4, may be adjusted to a desired angle of inclination. The adjustment member 9 comprises a reading device 10, see Fig 8, 9, 10, by which the actual angle of inclination of the back support 1 may be read. At such a mentioned violent vehicle accident the inner frame member 5 may thus pivot about the pin-like member 6 in relation to the outer frame member 4. How much the inner frame member 5 may pivot is determined by a locking mechanism 11 , see Fig 8, 9, 10.

The outer and inner frame members 4, 5, see Fig 6, comprise a lower frame part 4', 5', and an upper frame part 4", 5", which are displaceably provided in the lower frame part 4' and 5'. In such a manner it is possible to prolong the frame members 4 and 5 and thus adapt the back support 1 to individuals having different lengths. This adjustment may be done automatically or manually. The inner frame member 5 comprises a holding-up member in the form of a number of transverse bands 12 which extend between side bars of the inner frame member, see Fig 6 and 7, and are arranged to provide a powerful support at a possible collision. The holding-up member may be shaped in many other ways, for instance as two whole pieces, one for each of the frame parts 5' and 5".

The back support 1 also comprises a support element 13 provided in front of the back support holding-up member or the bands 12 and arranged to take a shape individually adapted to the user. The support element 13, see Fig 6 and 7, comprises a number of ceils 14 which are filled with some suitable material, preferably polyurethane plastic. Between the cells 14 and the bands 12, a valve member 15 in the form of three plates 15', 15" and 15'" is provided, which are provided with holes. The two outer plates 15' and 15"' are provided in such a manner that the holes 16 are aligned to each other and the intermediate plate 15" is displaceably provided between the two outer plates 15' and 15"' by means of a schematically indicated operating member 17 in such a manner that in a normal position the holes 16 of the intermediate plate 15" will cover the holes 16 of the outer plates 15' and 15'". In an open adjustment position, which is obtained by means of the operating member 17, the holes 16 of all of the plates 15', 15" and 15'" will be aligned to each other. When the driving person puts himself in the seat and opens the valve device 15 by means of the operating member 17, the air contained in the cells will be forced out and the support element 13 will take a shape which is adapted to the back contour of the driving person. When the valve device 15 is closed by release of the operating member 17 the shape taken will be maintained. It is to be noted that the adjustment and adaptation of the support element 13, for obtaining the best result, ought to be done when the back support 1 is in the protective position of inclination N. Thanks to such an adaptation of the shape of the support element 13 to the shape of the back bone a stretching of the curvature of the back bone is reduces to a minimum at such a violent vehicle accident. This aspect of the invention is particularly essential concerning female driving persons, the back bone of which has a significantly greater curvature than those of men. In front of the cells 14, i.e. towards the user, there is a relatively soft comfort layer 18. The back support disclosed in Fig 6 also comprises a channel 19 which is centrially provided in the centre on the inner frame member 5 and connected to the climate equipment of the vehicle for supply of warm or cold conditioning air through the comfort layer 18 of the back support 1.

The head support 3, see Fig 6, is fixedly provided on the inner frame member 5 and comprises a first lower section 20 and a number of upwardly displaceable sections 21 , in order to enable an individually adapted adjustment of the height position of the head support 3. This adjustment may be performed automatically or by means of an adjustment member 22. It is to be noted that also this adjustment, as well as the adjustment of the frame parts 5' and 5", for obtaining the best result ought to be done when the back support 1 is in the protective position of inclination N. As is indicated in Fig 6, the lower section 20 of the head support 3 is rotatable downwardly to function as a head support for short persons. As an alternative it is also possible to let the lower section 20 be displaceable downwardly to the position disclosed. The head support 3 is constructed of a relatively hard plastic material around which a cell polyethane material is provided. Furthermore, there are two support members 23 which in their one end are journalled to the uppermost section 21 of the head support 3 and in their other end are journalled to the outer frame member 4. The support member 23 are telescopically extendible and provided with a locking mechanism preventing the extended support member 23 from being pushed together again. In such a manner the position of the head support 3 in relation to the outer frame member 4 is ensured after the inner frame member 5 has been pivoted forwardly to the protective angle of inclination N after a collision, see Fig 5. It is to be noted that the locking mechanism merely goes into function at such a violent vehicle accident.

According to an alternative embodiment, the head support 3 may be kept together by means of a number of piston-like bars extending through all sections and into a respective cylinder fixedly provided to the inner frame member 5. In each cylinder there is a compression spring which, in the normal compressed state of the head support 3, is compressed and pretensioned. Thereby, the head support 3 comprises a wire extending through all sections 20, 21 and being fixedly provided in the uppermost section. The wire keeps the head support 3 in the normal compressed state. At a violent vehicle accident mentioned above the wire is released and the springs provided in the cylinders will lift the bars and thereby increase the distance between each section. In order to achieve the same distance between each section to bands extend through all sections and these are fixedly attached to each section.

Fig 8 discloses the construction of the seat bottom 2. The seat bottom comprises a framework 24 attached to the vehicle and on which six bolt members 25 are provided. The bolt members 25 extend through a respective longitudinal groove 26 in a seat frame

27 functioning as a force limiting member in a manner to be explained more closely below. In longitudinal grooves of the seat frame 27 the seat plate 8 is displaceably provided. At the front edge of the seat plate 8 a band 28 is attached. The band 28 is a part of the locking mechanism 11 comprising a reel 29 onto which the band

28 is wound. The reel 29 is rotatable and fixedly provided on the seat frame 27. The locking mechanism 1 1 and the reel 29 co¬ operate via a wire 30, for example a so called Bowden-cable, with the reading device 10 in such a manner that at said violent vehicle accident as much of the band 28 is unrolled that the seat plate 28 may be displaced rearwardly and the inner frame member 5 of the back support 1 may take the first safety position N. In the example disclosed the reading device 10 comprises two gears, one of which is connected to the adjustment member 9 and one to the wire 30. When the adjustment member 9 is rotated this movement of rotation will thus be transferred to the reel 29 by means of said gears. The construction and the function of the locking mechanism 11 and the reel 29 is explained more closely in connection with Fig 9 and 10. In order to keep the seat plate 8 and the inner frame member 5 in position during normal use of the seat device the seat plate 8 is pulled forwardly by means of two spring members 31 which at a first end are connected to the seat plate 8 and at a second end to the seat frame 27. When the inner frame member 5 is in the first safety position N and the acceleration rearwardly of the user in the seat device has been definitively completed the seat frame 27 will be displaced rearwardly in the vehicle in two steps by means of two damping members comprising a respective cylinder 32 attached to the frame work 24 and a respective piston 33 attached to the seat frame 27 and displaceable in the respective cylinder 32. Each cylinder 32 comprises a valve member 34 which is arranged to open when a certain pressure has been obtained in the cylinder 32, said second step being initiated.

Fig 9 discloses, according to another embodiment, the reading device 10 of the seat device and a locking mechanism 11 co¬ operating therewith. The locking mechanism 11 comprises a reel 39 which has a similar construction and operating function as the reel 29 described above and as a safety belt reel of known type with the difference that onto the reel are two wires 40 wound instead of a band. The reel 39 is attached to the outer frame member 4 and the wires 40 are attached to the inner frame member 5 by their ends in order to determine how much the inner frame member 5 may pivot in relation to the outer frame member 4. On the reel 39 there is a controllable locking plate 41 the function of which is to activate the locking mechanism of the reel 39, which is known per se from such safety belt reels and therefore is not more closely disclosed. On the other hand a stop member 42 is disclosed, which is provided on the locking mechanism 11 and arranged to co-operate with a projection

43 provided on the locking plate 41. When the back support 1 , i.e. the outer frame member 4, is moved rearwardly the projection 43 of the locking plate 41 will go apart from the stop member 42 and the distance between the projection 43 and the stop member 42 which thereby arises determines how much of the wire 40 that may be unrolled from the reel 39 at a collision. In the case disclosed the projection 43 of the locking plate 41 is immediately adjacent the stop member 42 since the back support 1 is at the normal protective angle of inclination N. This means that at a possible rear-end collision the reel 39 would immediately at the smallest possible load of the body against the inner frame member 5 be locked and thus without any unrolling of the wire from the reel 39. The locking plate 41 comprises a gear portion 44 which is in engagement with a sector-shaped gear wheel 45 journalled to the outer frame member 4. The sector-shaped gear wheel 45 comprises in turn a smaller gear wheel 46 which may rotate concentrically to the sector-shaped gear wheel 45. The smaller gear wheel 46 is in engagement with a further sector-shaped gear wheel 47 which is concentric to the adjustment axis 48 of the back support. It is to be noted that the sector-shaped gear wheel 47 is fixedly provided in relation to the seat device and at an adjustment of the back support 1 the smaller gear wheel 46 and thus also the sector-shaped gear wheel 45 will consequently rotate due to the engagement of the smaller gear wheel 46 with the sector-shaped gear wheel 47. This rotation is transferred via the sector-shaped gear wheel 45 to the gear portion

44 of the locking plate 41. In order to further ensure the fixed position of the sector-shaped gear wheel 47, this is connected to a stabilizing device 49 comprising a horizontal rail 49A in which a rod 49B or the like is displaceably provided. The rod 49B carries a vertical rail 49C in which a rod 49D or the like projecting from the sector-shaped gear wheel 47 is displaceably provided. The stabilizing device 49 enables the vertical and horizontal movement of the sector-shaped gear wheel 47 but which ensures that the sector-shaped gear wheel 47 always takes the same angle of inclination, which is essential for the greatest possible precision of the function of the reading device even at external violence against the back support 1.

At a further downward movement of the back support rearwardly from the protective angle of inclination N disclosed in the figure the reading device 45, 47 will automatically inform the locking mechanism 11 about how much wire 40 is to be unrolled from the reel 39 at a rear-end collision in order to in such a manner enabling the reset of the inner frame member 5 and the head support 3 to the normal protective angle of inclination N. In such a manner an essentially simultaneous retardation of the rearward movement of the head and the body may be obtained irrespective of the circumstance that the back support has had an incorrect position of adjustment prior to the collision. Thus, Fig 9 refers to a simpler embodiment of the invention which permits a return movement back to the protective angle of inclination from a too rearwardly inclined position.

Fig 10 discloses a variant of the arrangement disclosed in Fig 9. Thereby, the arrangement according to Fig 10 comprises two locking mechanisms 11A and 11B, which each has the same construction per se as the locking mechanism 38 disclosed in Fig 9. However, the locking mechanism 11A is arranged to provide a return movement of the inner frame member 5 of the back support 1 in the case that the back support 1 is adjusted too far rearwardly (U), see Fig 3A. On the other hand, the locking mechanism 11 B is arranged to provide a return movement of the back support 1 when this is adjusted in a too far forwardly inclined position (O), see Fig 3B. Thereby, it is to be noted that in order to enable such a return movement the pins 6 are formed by a wire 59 which at a rear-end collision permits the connection point formed by the pins 6 and the groove 7 to be displaced rearwardly. Furthermore, in the normal locked position the inner frame member 4 is to be somewhat forwardly displaced in relation to the outer frame member 5 at the mounting of the head support 3. Possibly the upper cross beam of the outer frame member 5 may be dispensed with. During a movement forwardly of the back support 1 the sector-shaped gear wheel 45 will rotate rearwardly and influence the gear portion 44 of the locking mechanism 11 B. When the back support 1 is inclined rearwardly the sector-shaped gear wheel 45 will be rotated forwardly and influence the gear portion 44 of the locking mechanism 11 A. By the seat device disclosed in Fig 10 the adjustment of the back support is performed by rotating the adjustment axis 48 by means of an adjustment wheel not disclosed, which engages two recesses 50. Thereby, a gear wheel 51 which is in engagement with a smaller gear wheel 52 which is fixedly connected to a pulley 53 is rotated. The pulley 53 influences via a belt 54 in turn a second pulley 53 which is fixedly connected to a third pulley 56 which via a belt 57 influences a fourth pulley 58 fixedly connected to the sector-shaped gear wheel 45. By this gearing arrangement it is obtained that a turn of rotation of the adjustment axis 48 corresponds to a turn of rotation of the respective locking plate 41. It is to be noted that the transfer of the rotational movement from the adjustment axis 48 to the locking plates 41 may be performed in many alternative manners and that Fig 10 merely defines one example. The wire 40 of the locking mechanism 11A is in the same way as is disclosed in Fig 9 connected to the inner frame member 5 by its ends, see Fig 7. Thus, the wire 59 of the other locking mechanism 11B extends transverse to through the outer and inner frame members 4, 5 and the discharge of the wire 59 permits resetting of the inner frame member 5 to the protective position of inclination N at a collision if the back support 1 is adjusted to a too far forwardly inclined position O.

In order to enable the driving persons always to be able, in a controlled manner, to choose such an adjustment of the back support 1 and the head support 3 that the risk of the appearance of whiplash injuries at a possible collision is minimal, the seat device comprises suitably a whiplash warning device mounted to the instrument panel of the vehicle. An example of such a whiplash warning device is disclosed in Fig 11. It comprises an indicating member 60 having a number of lamp members 61 provided in a row, which are lightened successively when the back support 1 is moved from the normal position of inclination N, either forwardly, O, or rearwardly, U. In such a manner the user is given information about in which position the back support 1 is located, in the case that the back support 1 exceeds the limit where the device according to the invention is capable of resetting the back support 1 to the protective position of inclination N, the lamps 62 located outside the protective area will be lightened. The lightening of these lamps may also be combined by a warning signal from a summer 63. Of course, it is to be possible to disconnect the whiplash warning device if one desires to move down the back support 1 completely for some reason. If a back support 1 is electrically manoeuvrable the seat device may comprise an adjustment memory by which the position for the angle of inclination O-U of the back support may be stored for a number of users. By pushing one of the memory keys 64 the back support 1 may thus be automatically adjusted, preferably within the frame of the adjusting capacity of the seat device. It is to be noted that the seat device according to the invention is developed by such an adjustment capacity that it is sufficient for comprising all normal driving and seating positions. The indicating member 60 may be electrically connected to the reading device 10 or to a reading device 66, which is disclosed as an example in Fig 10. The reading device 66 may comprise an electric terminal 67 which dependant on the angle of inclination of the back support 1 will be in electrical contact with one of a plurality of electrical terminals 68. In such a manner it may be decided by means of the different terminals 68 which of the lamp members 61 is to be lightened.

With reference to Fig 12 and 13 another embodiment of the seat device according to the invention is disclosed. In Fig 13A is disclosed how the back support of the seat device is adjusted to a safety position. In this position all adjustments of the head support 3 and the support element (see Fig 6 and 7) may be performed. Thereafter, the driving person may move the back support downwardly to a comfort position disclosed in Fig 13B. At a violent vehicle accident mentioned above, the seat device will be turned about an axis of rotation 70 as much that the back support 1 again is brought to the safety position adjusted. This is disclosed in Fig 19

13C. In Fig 13D is disclosed how the seat device is returned to a rearwardly displaced position after the driving person definitively has completed its rearward movement and no force is thus any longer applied by the driving person to the back support 1. By such a rearward displacement of the back support 1 is prevented, as is mentioned above, that the back support 1 throws the driving person forwardly. In order to enable the upright movement disclosed in Fig 13C the seat device according to this embodiment comprises a link system comprising a first pair of arms 71 which by their upper end are journalled to a frame 72 of the back support. At their lower ends the arms 71 are connected to each other via a shaft 73. Furthermore, on the shaft 73 a pair of second arms 74 are rotatably provided and these are in turn at their other ends journalled to a respective third arm 75, which in turn is journalled to a frame work 76 fixedly provided in the vehicle and comprising the axis of rotation 70. Furthermore, the back support 1 comprises a support plate 77 which may be attached to the frame 72 by means of a number of spring members 78. Behind the support plate 77 there are a first band 79 extending essentially horizontally and a second band 80 attached to the upper transverse portion of the frame 71 and tightened around this portion in such a manner that it extends behind the frame downwardly behind the support plate 77 and through a passage of the shaft 73 and is attached to the front end (not disclosed) of the seat bottom 2. Further support members in the shape of wires 82 may extend between the upper part of the frame 72 and the shaft 73. The support plate 77 may be constructed in many different ways, for instance as a net structure as disclosed. The back support 1 may be adjusted to the comfort position disclosed in Fig 13B by means of an adjustment member 9. This may be connected to a reading device and a locking mechanism 10, 11 , schematically disclosed, in a corresponding member as has been disclosed in the previous embodiments. Thereby, the locking mechanism is to be arranged in such a manner that it limits the upward movement of the seat device until the back support 1 is in the safety position, i.e. is inclined by the protective angle of inclination N in relation to the travel direction of the vehicle. At such a violent vehicle accident the body of the driving person will be forced rearwardly especially at the lower portion of the back support 1 , the support plate 77 and the band 80 transferring a rearwardly directed force to the arms 71. This means that the link arm system 71 , 74, 75 will be straightened, the back support 1 being lifted upwardly, i.e. the seat device is rotated about the axis of rotation 70. In order to maintain the seat device in position during normal use a schematically disclosed damping member 83 may be provided in the seat bottom 2 and arranged to counteract the displacement rearwardly of the link between the arms 74 and 75 by a determined force. The seat bottom 2 may also according to this embodiment comprise a seat plate 8 which is connected to the shaft 73 and at its front edge bears against a frame work 76 or the floor of the vehicle via an arm 84. In such a manner the seat plate 8 will be able to maintain the same inclination as in the safety position although other parts of the seat is pivoted upwardly at a collision. The locking mechanism may also in this embodiment comprise a reel 85 which is arranged to wind a length of the band 80, which is determined by the reading device according to Fig 8, in order to limit the upright movement of the back support 1 to the safety position N.

The invention is not in any way limited to the embodiments disclosed above but may be modified and varied within the scope of the following claims.

For instance, It is to be noted that the mechanical reading device disclosed would be replaceable by an essentially electrical device with for example proximity sensing members sensing the exact position of inclination of the back support 1. By means of for instance an electric motor, this sensed position of inclination may result in a corresponding rotation of the locking plate 38.

Finally, it is to be mentioned that the mounting of the seat device in the vehicle may be such that the seat device is movable about a point of rotation provided under a forward part of the seat bottom 2. In such a manner it is obtained that at a rear-end collision from obliquely rearwardly the seat device is oriented in the direction of acceleration caused by the collision.

Claims

1. A seat device for a motor vehicle, comprising a seat bottom (2) and a back support (1 ), arranged to provide a support for the head, the neck and the back portion of a user sitting in the seat device, the back support (1 ) having a first angle of inclination in relation to the normal travel direction of the vehicle, characterized bv first means (10, 1 1 ) which, at a violent vehicle accident, such a rear-end collision but also secondarily after a frontal collision, during which the head, the neck and the back portion is rearwardly accelerated, and irrespective of the first angle of inclination (O-U) of the back support (1 ), are arranged to provide the movement of the back support to such a first safety position (N) that simultaneity of the retardation of said acceleration of the head, the neck and the back portion is essentially obtained.

2. A seat device according to claim 1 , characterized in that said first safety position comprises a protective angle of inclination (N) of the back support (1 ), which may be predetermined or adaptable to different situations.

3. A seat device according to any one of claims 1 and 2, characterized bv displacement members (32, 33) which, after the back support (1 ) has taken said first safety position (N), are arranged to provide a rearward displacement of the back support (1 ) when the body has completed its rearward movement.

4. A seat device according to claims 2 and 3, characterized in that the displacement members (32, 33) are arranged to provide said rearward displacement while maintaining said protective angle of inclination (N).

5. A seat device according to any one of the preceding claims, characterized in that the first angle of inclination of the back support

(1 ) is adjustable or fixed in a position of use which is comfortable to the user. 6. A seat device according to any one of the preceding claims, characterized in that the first means (10, 11 ), at said violent vehicle accident, are arranged to utilize the kinetic energy of the user accelerated rearwardly in order to provide the force necessary to bring the back support (1 ) to said first safety position (N).

7. A seat device according to any one of the preceding claims, characterized in that the first means comprises a reading device (10, 45 - 58) arranged to sense the first angle of inclination (O-U) of the back support (1 ).

8. A seat device according to claim 7, characterized in that the first means comprise a locking mechanism (11 , 11 A, 11 B) arranged to permit the movement of the back support (1 ) from the first angle of inclination to said safety position (N) and to lock the back support (1 ) in this position.

9. A seat device according to claim 8, characterized in that the locking mechanism (11 ) comprises a reel (29, 39) onto which a wire member is wound and that the locking mechanism (29, 38) is arranged to co-operate with the reading device (10, 45 47) in such a manner that as much of the wire member is unrolled that the back support may take the first safety position (N) at said violent vehicle accident.

10. A seat device according to any one of the preceding claims, characterized in that the back support (1 ) comprises an outer frame member (4) and an inner frame member (5) comprising a back support member and being pivotably mounted to the outer frame member.

11. A seat device according to claim 10, characterized in that the seat bottom (2) comprises a seat plate (8) displaceably provided in the seat bottom (2) and journalled to the inner frame member (5). 12. A seat device according to any one of claims 10 and 11 , characterized bv blocking members (31 ) arranged to lock the inner frame member (5) in a fixed position in relation to the outer frame member (4) during normal use and to release the inner frame member (5) in relation to the outer frame member (4) at said violent vehicle accident.

13. A seat device according to any one of the preceding claims, characterized bv a head support (3) provided on the back support (1 ) and in that at least one of the head support and the back support is prolongable upwardly in a direction away from the seat bottom (2) in order to ensure that the head of the user is supported by the head support (3) irrespective of the length of the user.

14. A seat device according to any one of the preceding claims, characterized in that the back support (1 ) comprises a holding-up member (12) and a support element (13) provided in front of the holding-up member, i.e. facing the user, and arranged to take a shape individually adapted to the user.

15. A seat device according to claim 14, characterized in that the support element (13) comprises a number of cells (14) arranged to take a shape which is adapted to the user by discharge of gas contained in the cells.

AMENDED CLAIMS

[received by the International Bureau on 15 August 1997 ( 15.08.97) ; original claims 1 -15 replaced by new claims 1 -19 (4 pages ) ]

1. A seat device for a motor vehicle, comprising a seat bottom (2) and a back support (1 ), arranged to provide a support for the head, the neck and the back portion of a user sitting in the seat device, the back support (1 ) having a first angle of inclination in relation to the normal travel direction of the vehicle, characterized bv first means (10, 11 ) which, at a violent vehicle accident, such a rear-end collision but also secondarily after a frontal collision, during which the head, the neck and the back portion is rearwardly accelerated, and irrespective of the first angle of inclination (O-U) of the back support (1 ), are arranged to provide the movement of the back support to such a first safety position (N) that simultaneity of the retardation of said acceleration of the head, the neck and the back portion is essentially obtained.

3. A seat device according to any one of claims 1 and 2, characterized in that the protective angle of inclination (N) of the back support is choosen in such a manner that the back support prevents the uppermost cervical vertebrae, atlas and axis, from being locked in a certain position of rotation in relation to each other.

4. A seat device according to any one of claims 1 -3, characterized by displacement members (32, 33) which, after the back support (1 ) has taken said first safety position (N), are arranged to provide a rearward displacement of the back support (1 ).

5. A seat device according to claim 4, characterized in that the displacement members (32, 33) are arranged to provide said rearward displacement while maintaining said protective angle of inclination (N).

6. A seat device according to any one of the preceding claims, characterized bv displacement members comprising at least one of a damping member (32, 33) in connection with a valve member (34) and a link arm system (71 , 74, 75) which are arranged to provide a rearward displacement of the back support (1 ) when the body has completed its rearward movement.

7. A seat device according to any one of the preceding claims, characterized in that the first angle of inclination of the back support (1 ) is adjustable or fixed in a position of use which is comfortable to the user.

8. A seat device according to any one of the preceding claims, characterized in that the first means (10, 11 ), at said violent vehicle accident, are arranged to utilize the kinetic energy of the user accelerated rearwardly in order to provide the force necessary to bring the back support (1 ) to said first safety position (N).

9. A seat device according to any one of the preceding claims, characterized in that the first means comprises a reading device (10, 45 - 58) arranged to sense the first angle of inclination (O-U) of the back support (1 ).

10. A seat device according to claim 9, characterized in that the first means comprise a locking mechanism (11 , 11 A, 11 B) arranged to permit the movement of the back support (1 ) from the first angle of inclination to said safety position (N) and to lock the back support (1 ) in this position.

11. A seat device according to claim 10, characterized in that the locking mechanism (11 ) comprises a reel (29, 39) onto which a wire member is wound and that the locking mechanism (29, 38) is arranged to co-operate with the reading device (10, 45, 47) in such a manner that as much of the wire member is unrolled that the back support may take the first safety position (N) at said violent vehicle accident.

12. A seat device according to claim 9, characterized in that the locking mechanism comprises a disengageable blocking piece, e.g. a kind of angle bar iron, by which the back support irrespective of the adjusted angle of inclination will be brought to an angle of inclination (N) determined by the blocking piece at a collision.

13. A seat device according to any one of the preceding claims, characterized in that the back support (1 ) comprises an outer frame member (4) and an inner frame member (5) comprising a back support member and being pivotably mounted to the outer frame member.

14. A seat device according to claim 13, characterized in that the seat bottom (2) comprises a seat plate (8) displaceably provided in the seat bottom (2) and journalled to the inner frame member (5).

15. A seat device according to any one of claims 13 and 14, characterized bv blocking members (31 ) arranged to lock the inner frame member (5) in a fixed position in relation to the outer frame member (4) during normal use and to release the inner frame member (5) in relation to the outer frame member (4) at said violent vehicle accident.

16. A seat device according to any one of the preceding claims, characterized bv a head support (3) provided on the back support (1 ) and in that at least one of the head support and the back support is prolongable upwardly in a direction away from the seat bottom (2) in order to ensure that the head of the user is supported by the head support (3) irrespective of the length of the user.

17. A seat device according to any one of the preceding claims, characterized in that the back support (1 ) comprises a holding-up member (12) and a support element (13) provided in front of the holding-up member, i.e. facing the user, and arranged to take a shape individually adapted to the user.

18. A seat device according to claim 17, characterized in that the support element (13) comprises a number of cells (14) arranged to take a shape which is adapted to the user by discharge of gas contained in the cells.

19. A seat device according to any one of the preceding claims, characterized in that the seat device is provided to be oriented in the direction of acceleration caused by the collision.