Seat, particularly for motor vehicles

Abstract

A seat, particularly for motor vehicles, which automatically performs at adjustable time intervals, deformations of the seat pad and the seat back-rest cooperating with a strap system, causing changes in the sitting position so as to counteract fatigue symptoms of the body, especially of the spinal column.

Description

FIELD OF THE INVENTION

This invention relates to a seat particularly for motor vehicles. It is generally known that extended periods of driving bring about fatigue symptoms resulting from spinal troubles. Such spinal troubles are known to occur after any extended period in a sitting position and are generally caused by two factors:

1. FATIGUE DUE TO EXCESSIVE STRAIN ON INDIVIDUAL MOTION SEGMENTS,

2. IMPAIRED SUPPLY OF THE INTERARTICULAR DISKS DUE TO LACK OF MOVEMENT.

The interarticular disks are cushion-like pliable structures of a fibrous and cartilaginous nature disposed between individual vertebrae. As these disks do not contain any blood vessels, they are dependent on humoral blood supply, as far as admitted by the permeability of the tissue. This humoral blood supply can be considerably improved by changes in the pressure load, i.e. by a kind of "pumping effect" caused by movements particularly of the spinal column.

BACKGROUND OF THE INVENTION

It is well known to any motorist that even orthopedically well-designed seats are unable to prevent such fatigue phenomena over more than a rather short period. That is because even the most favourable sitting position cannot cause any movements, thus inevitably causing fatigue, since the weight of the upper part of the body is continually supported by the interarticular disks. Thus for preventing the occurrence of fatigue, the position of the spinal column should continually change, or the driver should assume a substantially reclining position, which is obviously impossible for the driver of a motor vehicle. It is an object of the invention to provide an antifatigue seat adapted to change the curvature of the spinal column of an occupant independent of any action on the part of such occupant. To attain this object the invention provides a seat comprising devices for causing the seat to perform movements, and thus, deformations, at certain time intervals so as to automatically bring about changes of the sitting position. This results in the advantage that the seat transmits a fatigue-reducing movement at certain time intervals to body portions affected by the sitting position, without the aid of the seat occupant.

In an advantageous embodiment of the invention the seat is provided with a shoulder strap for retaining the upper part of the body and pulling it back against the back of the seat, and a device for producing a forward curvature of the back-rest at the height of the lumbar region of the spinal column. In this case it is particularly advantageous if the backwards pulling action of the straps and the forward-arching of the back rest are coordinated in a certain manner, specifically, if the movements of the two devices occur simultaneously. This leads to an expansion and compression of the interarticulate disks resulting in a pumping action which has particularly beneficial effects on the turgor, i.e. the interior pressure and the strength of these tissues which in many motorists already show signs of damage. In addition there occurs simultaneously a mild massage of the back muscles effective to counteract fatigue.

The shoulder straps are preferably designed as "suspender straps" extending vertically or even slightly divergent downwards from the shoulders, so that they do not interfere with breathing or with the female breast. In this configuration the shoulder straps are retained by a horizontal cross-strap which may be formed to serve as an additional lap-strap. The cross-strap is preferably stiffened so as to prevent the shoulder straps approaching each other and to thus ensure the unhindered function of the thoracic organs. The cross-strap may further be formed as a two- or four-point buckle.

For further enhancing the movements of an occupant's spinal column there may be provided a further device at the back rest between the shoulder straps for urging the thoracic spinal column forwards at certain time intervals. This results in an additional direction of movement in a different plane.

Further there may be provided additional means for causing deformation of the seat pad itself as well as further deformations of the seat adapted to the needs of the particular occupant e.g. for massageing individual organs .

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described with reference to several embodiments thereof showing further particulars and advantages. In the accompanying drawings:

FIG. 1 shows a side elevation of a deformable seat provided with a shoulder retaining strap,

FIG. 2 shows a top plan view of the seat of FIG. 1,

FIG. 3 shows a side elevation corresponding to FIG. 1 of a deformed seat comprising a pneumatic system for deforming the region of the thoracic spinal column with simultaneous backpulling of the shoulders,

FIG. 4 shows a side elevation corresponding to FIGS. 1 and 3 of a deformed seat provided with a mechanical device for pulling the shoulder straps backwards,

FIG. 5 a diagram of a program of the time intervals for the continuous and alternating movement of the devices causing deformation of the seat,

FIG. 6 shows in dotted lines the back rest of a seat including a number of hollow body devices cooperating with a control device and a pressure source in a second embodiment of the invention,

FIG. 7 shows diagrammatically the deformation sequence of the hollow body devices shown in FIG. 6 with simultaneous backpulling of the shoulders,

FIG. 8 a diagram corresponding to that of FIG. 7, but with a different amplitude and frequency of the deformation movements of the hollow bodies,

FIG. 9 shows a front elevation of the strap system for retaining the shoulders in another embodiment,

FIG. 10 shows a front elevation of a person seated in front of the back rest of a seat with the shoulder loops in raised position,

FIG. 11 shows a view corresponding to FIG. 10 with the shoulder loops lowered to their operational position,

FIG. 12 shows a side elevation of the seat shown in FIG. 11,

FIG. 13 shows a front elevation of the back rest of a seat including deformable hollow bodies provided with sensing means, and

FIG. 14 shows a side elevation of the shoulder loops provided with sensors.

DETAILED DESCRIPTION

In the embodiment of FIGS. 1 to 5 there is shown, in FIGS. 1, 3, and 4, a person occupying the seat according to the invention. In order to avoid fatigue phenomena on motionless seat occupancy over extended periods, the seat pad 6 and the back rest 3 are adapted to be deformed by devices 1, 2, 5, and 7. The deformation device 2 serves for arching the back rest forwardly in the lumbar region. The device 5 serves for urging the thoracic spinal column forwards, while a further device simultaneously causes the strap 1 to be pulled backwards in the direction of arrow 4 for retaining the shoulders. Deformation of the seat pad 6 is effected by the device 7 acting on the thighs and the pelvis.

FIG. 2 shows the action of the device 5 on the thoracic spinal column intermediately between the attachment points 8 of the shoulder straps to the back rest for rounding the shoulders backwards. A further embodiment of a device 11 acting on the shoulder straps 10 and simultaneously on the thoracic spinal column in the direction of arrow 12 is shown in FIG. 3. This device causes deformation of the back rest and applies tension to the straps 10.

FIG. 4 shows a third embodiment of a mechanical device 13 for applying tension to the shoulder straps. This device 13 comprises a shaft adapted to wind the shoulder strap wound thereon. There are shown as well the hollow body devices 14 and 15, which are comparable to those devices 5 and 2 of FIG. 1.

An example of a program for the various deformation movements of the seat according to the invention at certain time intervals is shown in a cyclic diagram in FIG. 5. Therein the sequence of the movements is selected as follows: Deformation in the lumbar and thoracic region with simultaneous backpulling of the shoulders during a period 16 of 15 secs. duration. Decrease of these deformations during the following period 17 of 15 secs. duration. Backward movement of the pelvis with simultaneous lifting of the thighs during a time interval 18 of 30 to 45 secs. duration. During the following interval 19 the preceding deformations are reduced to zero, whereupon a new cycle is started.

In a further embodiment of the seat according to the invention shown in FIGS. 6 to 9, only the outline of the back rest 20 is shown for a better understanding of the invention. The seat may be a simple chair or it may be provided with upholstered seat pad and back rest in the manner known from conventional vehicle and aircraft seats. In order to avoid fatigue symptoms occurring after extended periods of motionless sitting, this embodiment is also provided, within the seating pad as well as in the back rest, with devices for automatically effecting changes in the sitting position.

According to the invention, the devices installed in the back rest are formed by resiliently expansible hollow bodies 21, 22 and 23. In this case there is provided for each shoulder region a hollow body 21 of a corresponding size, further an elongate hollow body 22 extending symmetrically to the longitudinal center of the back rest in the longitudinal direction of the back, and further a futher hollow body 23 engaging the lumbar or pelvic region, each of said hollow bodies being of a shape and size corresponding to the respective body region. The seat pad may be constructed in a like manner for acting on the thighs and/or on the pelvis of a seat occupant.

In order to enable the hollow body devices to bring about changes in the sitting position, they may be connected through pipes or hoses to a pressure medium source of constant or variable pressure. In the latter case, pressure variations are controlled in accordance with a predetermined timing program. The hollow bodies are supported at their rear sides, so that a pressure increase causes them to be resiliently expanded in a forward direction. A pressure decrease, possibly with controlled escape of the pressure medium, causes the hollow bodies to automatically resume their original configuration due to the resiliently expansible material thereof.

Preferably a hydraulic or pneumatic pressure medium source 24 usually incorporated in a motor vehicle or aircraft, for example, is employed for supplying the hollow bodies 21, 22 and 23. This type of pressure medium source, however, has usually a constant pressure. In this case the pressure medium is supplied to the hollow bodies 21, 22 and 23 through an electrically controllable distribution valve assembly 25 of a control device, and further through piping or tubing 26. For further pressure control, the hollow bodies are additionally connected to a further electrically controllable valve assembly 27 of the control device, said valve assembly consisting essentially of relief valves. Finally the control device comprises a selectively programmed electrical pulse generator 28 connected through leads 29 to the valve assemblies 25 and 27 for actuation thereof in accordance with electrical pulses scanned off a program card inserted therein. The program of said program card 30 may include all of the deformation movements of the two shoulder devices 21, of the back rest device 22 and of the lumbar device 23, as well as the sequence of the various deformation movements and the control thereof with respect to frequency and amplitude. Thus the entire sequence of the motion cycle of the hollow body devices may be controlled in accordance with a predetermined program by scanning a program card by means of a timing switch assembly in a similar manner as in an electrically controlled washing machine. The pulse generator 28 may also, however, comprise exteriorly actuable adjusting means 31, 32 for selecting the frequency and amplitude, respectively, so that the frequency and amplitude are the same for all hollow body devices during the motion cycle. On the other hand it is also possible to adjust the frequency and amplitude for each hollow body individually by means of individual adjusting means. Also the apparatus may be so constructed that the deformation movements of the seat pad and the back rest are separately adjustable.

The exit side of the valve assembly 27, which consists essentially of electrically controllable relief valves, is connected via a tube or pipe 33 to the intake side of the pressure medium source 24. This connection, however, is only provided in case of a hydraulic pressure medium being employed. If the employed pressure medium is air, the pressure reduction in the hollow body devices is effected by exhausting such air through the relief valves to the atmosphere.

In order that the hollow body devices 21, 22 and 23 may exert their full effect on the seat occupant for changing the curvature of his spinal column, there is provided a strap system as a counter support see FIG. 9. The strap system consists of two suspender-like shoulder straps 34 extending vertically or slightly divergent downwards from the shoulders along the front of the upper part of the body, so as not to interfere with breathing or with the female breast. In order to retain the straps 34 in this position they are connected, at the height of the pelvis, to a lap strap 35. To ensure the correct spacing of the shoulder straps 34, the portion of the lap strap 35 extending between the shoulder straps is stiffened or formed by a relatively rigid cross member 36. Possibly the cross member 36 may be provided with a buckle 37, or it may be designed as a two or four point buckle. The stiffened lap strap portion or member 36 prevents the shoulder straps' approaching each other so as to ensure unimpeded functioning of the thoracic organs. According to the invention, there is additionally provided a device acting on the shoulder straps so as to exert a backward pull on the shoulders during the deformation movement cycle for rounding the shoulders backwards. The strap system may be omitted, however, in a seat intended for a backwards reclining position such as in a television chair.

The timing sequence of the deformation movements of the back rest of a seat under the control of a complete program card 30 through the above described control device is shown in FIGS. 7 and 8 in the form of a half-wave along a time line substantially corresponding to one movement cycle the duration of which has been selected as being 10 minutes. The apex height of the half-waves represents the amplitude of the respective movements of the hollow body devices. In this diagram, the lumbar hollow body has been designated L, the back hollow body R, the hollow body, or bodies, respectively, for applying tension to the shoulder straps G and the shoulder hollow bodies, S. In the programmed sequence shown in FIG. 7, the first hollow body to be deformed is the hollow body L engaging the lumbar region, followed after an interval of one minute by the sequential deformation of the back hollow body R and the shoulder hollow bodies S, with intermediately superimposed tensioning of the shoulder straps by means of the hollow body G for pulling the shoulders backwards. The deformation movements of the four hollow body devices all have the same frequency and amplitude. If the pulse generator is equipped with adjustment means for the frequency and amplitude of the movements of the various hollow body devices, the frequencies and amplitudes during one movement cycle of the hollow bodies may be different for each one thereof, as shown in FIG. 7 by dotted lines.

FIG. 8 shows a corresponding diagram of a movement cycle of the four hollow body devices with a different sequence of the deformations. The frequencies and amplitudes of the deformations are again identical, although different from those of the preceding example. Deformation of the shoulder strap hollow body G occurs simultaneously with that of the back hollow body R. Also in this example, the frequencies and amplitudes of the various deformation movements within one movement cycle may be adjusted to different levels by suitable arrangement and programming of the pulse generator.

In the FIGS. 10 - 12 there is shown a further embodiment of the seat according to the invention. This seat is preferably used stationary. The suspender-like shoulder straps or lap straps from the foregoing embodiments are replaced by upholstered loops 38 and 39. While in FIG. 10 these loops are shown in their raised position, they are shown in FIG. 11 in their lowered, operational position. If the shoulder loops are arranged in their raised position as shown in FIG. 10, they may easily be twisted or tilted in whatever direction. In FIG. 12 a side elevation of the seat in question is shown. The arrow 41 shows the direction in which the shoulder loops are lowered from their raised position into their operational position. Furthermore, there is shown a pelvis loop 40 which is movable from its inoperational position shown in FIG. 12 in the direction of the arrow 42 into its operational, tight position. This pelvis loop may be upholstered as well.

In FIG. 13 a seat is shown similar to that shown in FIG. 6 with the one difference that the deformable hollow bodies 43, 44 and 45 are provided with sensing means 46. These sensing means are connected via sensing lines 47 to the electrical pulse generator 28. The sensing means will measure the pressure which is exerted either by the body of the sitting person or by the pressure within the hollow body devices and will send a signal back to the electrical pulse generator in order to limit or to lower the pressure exerted. The sensing means 46 may be regular art like they are sold for similar purposes. According to the kind of sensing means, the sensing lines might be electrical wires or fluid pipes. The signals coming from these sensing lines will be converted into convenient impulses which will cause reactions up to the pressure within the hollow body devices.

In FIG. 14 a shoulder loop 48 is shown which is provided with a sensor 49 which reacts in the same manner as those sensors 46 shown in FIG. 13. These sensors 49 are also connected by not shown sensing lines to the electrical pulse generator.

Claims

I claim:

1. In a seat comprising at least one support surface having a surface facing a user of said seat, the improvement comprising means for producing a forward curvature of said support surface as a function of time in a defined area of said support surface and at a level of a specific portion of the user's spinal column abutting on said support surface to physically flex said spinal column adjacent said support surface and at least one shoulder strap for holding the shoulders of said user in engagement with said support surface.

2. An improved seat according to claim 1, including control means for subjecting said shoulder strap to tension and releasing said tension in order to hold the body of said user adjacent said shoulders and to pull said user's shoulders backward against said support surface of said seat.

3. An improved seat according to claim 2, wherein said means for producing said forward curvature in said support surface of said seat is arranged at a level of the lumbar spinal column of said user and wherein said backward pulling of said shoulder strap and the production of the forward curvature are coordinated in a predetermined manner by said control means.

4. A seat according to claim 3, wherein said control means effects a simultaneous backward pulling of said shoulder strap and said forward curvature of said support surface.

5. An improved seat according to claim 2, wherein said control means urges said support surface between the shoulder strap and at the height of the shoulders forward at predetermined time intervals to flex the thoracic spinal column.

6. An improved seat according to claim 2, including a deformable seat pad, the deformations of which are caused by said control means which coordinate the movements thereof with the movements of the support surface.

7. An improved seat according to claim 1, wherein said strap can function as a safety belt.

8. An improved seat according to claim 1, wherein said surface is defined by resiliently expandable hollow bodies connected to a hydraulic or pneumatic pressure medium source.

9. An improved seat according to claim 8, including a deformable seat pad, the deformations of which are caused by said control means which coordinate the movements thereof with the movements of the support surface; and

wherein the cycle of deformations of the seat pad and of the support surface cooperating with said strap is adjustable with respect to its frequency, amplitude and sequence by means of said control means.

10. An improved seat according to claim 9, wherein said control means is a programmable control device.

11. An improved seat according to claim 10, wherein said control device cooperating with said pressure source comprises a valve assembly for distributing the pressure medium to the hollow body devices and including a further valve assembly formed by relief valves for the hollow body devices, and wherein said programmable control device is a pulse generator and wherein both valve assemblies are adapted to be electrically controlled by said pulse generator with respect to the frequency, amplitude and sequence of the deformation movements.

12. An improved seat according to claim 10, wherein said pulse generator is provided with at least two exteriorly accessible adjusting means for manual adjustment or readjustment of the frequency and amplitude of the deformation movements.

13. An improved seat according to claim 10, wherein said pressure source is a hydraulic pressure medium source, the outlet side of said relief valve assembly being connected through tubing or piping to an inlet side of said pressure medium source.

14. An improved seat according to claim 10, wherein said programmable control device effects a control of the pressure of said pressure medium source to cause the deformation movements of said hollow body devices and is adapted to be varied by means of a programmed timing switch assembly therein.

15. An improved seat according to claim 10, wherein said control device is so designed that the deformation movements of the seat pad and of the back rest are separately adjustable.

16. An improved seat according to claim 10, including two shoulder straps and a lap strap, said lap strap being stiffened or formed as a substantially rigid cross-member between said shoulder straps so as to maintain the spacing therebetween, and being optionally provided with a strap buckle.

17. An improved seat according to claim 16, wherein said suspenderlike shoulder straps or lap strap are comprised of upholstered loops.

18. An improved seat according to claim 2, wherein said support surfaces include sensors operatively connected to said control device for limiting the magnitude of deformation.