GB2303300A

GB2303300A - Lumbar support for a seat

Info

Publication number: GB2303300A
Application number: GB9614735A
Authority: GB
Inventors: Dennis J Gryp; Edward L Stulik
Original assignee: Sears Manufacturing Co
Current assignee: Sears Manufacturing Co
Priority date: 1995-07-13
Filing date: 1996-07-12
Publication date: 1997-02-19
Also published as: GB9614735D0

Description

Backqround of The Invention The present invention relates generally to a lumbar support system for a seat and, more specifically, to a lumbar device having a unique configuration to allow fully adjustable ergonomically correct lumbar support for a wide variety of seat occupants and a pneumatic actuation means for a lumbar device.

The present invention provides a lumbar support device including a body portion, or support pan, and appendages having compound curvature, curving both horizontally and vertically, to fully support the lumbar region of a seat occupant.

support support systems have become increasing popular in the vehicular seating market in recent years. The demand for adjustable, eronomically appropriate lumbar support in seats has led to a proliferation of developments in this area. Nonetheless, a need still exists for a mechanically simple, cost-effective, highly adjustable and ergonomically correct lumbar support for use in vehicle seating.

Summary of the Invention The present invention is directed to a simple, cost-effective lumbar support device which is both adjustable and ergonomically correct. The lumbar support system of the present invention comprises a support pan which is curved horizontally to provide support around the body and is curved vertically to provide support to the spine. Extending above and below the support pan are a plurality of flexible support appendages. The support pan, configured to be relatively inflexible, provides the primary support. The appendages provide additional support extending up and down from the support pan and forming the same general multiple curvature contours to provide full, ergonomically correct support.

Further, because the appendages are somewhat flexible, as the occupant moves within the seat, or as occupants vary, the appendages will flex to provide lumbar support to the seat occupant as needed.

The present invention also provides a pneumatic actuator which consists of an air bag, an air-tight flexible enclosure with an air inlet and outlet. This pneumatic actuator is attached to the support pan, preferably across the entirety of the support pan. It expands when pressurized air is received to move the support pan into the seatback cushion toward the occupant to provide lumbar support. It deflates when air is discharged, allowing the support pan to recede. Use of a pneumatic actuator allows the seat occupant to adjust the lumbar support device of the present invention to an infinite number of positions rather than, as with most mechanical configurations, a discreet number of predetermined positions.

The present invention can also be employed with mechanical adjustment devices well known in the art. For instance, a suitable mechanical adjustment device is disclosed in U.S. Patent No.

5,299,851 to Lin and is incorporated herein by reference.

Thus, an object of the present invention is to provide a support pan of a lumbar support device contoured to provide ergonomic support both horizontally and vertically.

Another object of the present invention is to provide a lumbar support device with flexible appendages extending from the support pan which provide flexible and self-adjusting lumbar support.

Another object of the present invention is to provide a single-piece support pan which is relatively easy and economical to manufacture and service.

Another object of the present invention is to provide an ergonomically correct lumbar support pan with compound, horizontal and vertical, curvature and which is sufficiently resilient to retain its ergonomically correct curvature as it is employed to provide varying lumbar support.

Another object of the present invention is to provide a lumbar device which, when actuated, has only smooth contours and transitions to provide maximum support, comfort and flexibility.

Another object of the present invention is to provide simple and economical pneumatic actuation means for a lumbar support device.

Another object of the present invention is to provide a variably flexible lumbar support device to accommodate a wide variety of seat occupants and seat occupant positioning.

Description Of The Drawings The novel features which are characteristic of the present invention are set forth in the appended claims. However, the invention's preferred embodiments, together with further objects and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which:: FIGURE 1 is a perspective view showing the support pan and appendages of the lumbar support system of the present invention in conjunction with a seatback cushion; FIGURE 2 is a rear, elevational view showing some key components of the lumbar support system of the present invention; FIGURE 3 is a rear. elevatinnsl view showing some kev components of the lumbar support system of the present invention; FIGURE 4 is a cross-sectional view of the lumbar support system of the present invention along the line 4-4 of FIGURE 3 in conjunction with a seat backrest, shown in an inactivated state; FIGURE 5 is a cross-sectional view of the present invention along the line 5-5 of FIGURE 3 similar to FIGURE 4 but illustrating the inflatable actuator operationally engaging the lumbar support device;; FIGURE 6 is a cross-sectional view of the lumbar support system of the present invention.

FIGURE 7 is a cross-sectional view of the lumbar support system of the present invention along the line 7-7 of FIGURE 6.

FIGURE 8 is a cross-sectional view of the present invention along the line 8-8 of FIGURE 4; FIGURE 9 is a side cross-sectional view of the present invention along the line 9-9 of FIGURE 5 showing the inflatable actuator inflated.

Detailed Description Of The Preferred Embodiment The preferred embodiment of the lumbar support device, as shown in FIGURE 1 and designated generally 10, includes a body portion, or support pan, 12 and outwardly extending appendages 15.

Support pan 12 is preferably made of substantially inflexible plastic material and is curved horizontally and vertically. A side cross-sectional view, shown in FIGURE 6, shows that support pan 12 is vertically convex with the forward-most portion directed toward seatback cushion 20. A top cross-sectional view, as shown in FIGURES 7 and 8, shows that support pan 12 is also horizontally concave. The compound curvature of support pan 12 provides full lumbar support to a seat occupant. The convex curvature supports the spine of the seat occupant while the concave curvature wraps around the back of the seat occupant to support the back of the seat occupant in any position in the seat. Furthermore, support pan 12 is relatively inflexible and resilient to provide constant support of the seat occupant.

Extending from support pan 12 in both vertical directions are a plurality of relatively flexible support appendages 15.

Appendages 15 extend from support pan 12 to define substantially similar contours as support pan 12.

Lumbar support device 10 of the present invention is attached to seatback cushion 20 such that when, in operation, support pan 12 is pushed into seatback cushion 20, seatback cushion 20 bulges outward toward a seat occupant and maintains the contours of support pan 12 to support the lumbar, spine and back of a seat occupant. In operation, when support pan 12 is forced inward toward seatback cushion 20, appendages 15 will flex around and behind support pan 12 to provide variable support to a seat occupant. Support pan 12 is relatively inflexible and provides primary support to a seat occupant. Appendages 15 are more flexible and will flex somewhat based on the pressure exerted on them by the seat occupant.Thus, a seat occupant requiring more support in one region of his or her lumbar region will receive more support from appendages 15 and a seat occupant requiring less support will receive less. It will be appreciated by those of ordinary skill in the art that varying the number, shape, length and flexibility of appendages 15 will vary the support provided by appendages 15. The preferred embodiment of the present invention thus provides variable, self-adjustable support.

As shown in FIGURES 3 and 4, the lumbar support system of the present invention is preferably assembled between a seatback cushion 20 and a resilient seatback plate 22. Between plate 22 and lumbar support device 10 of the present invention is means for causing support pan 12 to be moved into seatback cushion 20. The preferred means of actuating lumbar support device 10 of the present invention is with an air bag pneumatic actuator 30.

Pneumatic actuator 30 is preferably connected to support pan 12 along the entire length of support pan 12. Air bag 30 has integrally heat-molded thereto a durable plastic mounting strap 26.

Mounting strap 26 is attached to support pan 12 via rivets or any other suitable means as is well known to those of ordinary skill in the art.

As shown in FIGURE 9, actuator 30 has an air inlet and outlet 34. Air inlet/outlet 34 has an air hose 35 in fluid communication with a pressurized air source (not shown). The preferable pressure of the compressed air is approximately 6-10 pounds per square inch ("p.s.i"), and most preferably approximately 8 p.s.i., as is available in many class 6, 7, and 8 vehicles. Along air hose 35 is a common rocker type valve (not shown) to allow or prevent air flow through hose 35 which is well known to those of ordinary skill in the art and can be actuated by the user to cause air to enter air bag 30 or to vent from air bag 30.

The air hose rocker valve is preferably mounted in convenient proximity to the seat occupant. As such, a seat occupant, when desiring to actuate lumbar support system 25 of the present invention, can conveniently operate the rocker valve to allow pressurized air to fill air bag 30. As air bag 30 fills with air, it expands which exerts a force against back plate 22. Because back plate 22 is relatively immovable, the expansion of air bag 30 causes support pan 12 to be pushed into seatback cushion 20 thus pushing seatback cushion 20 towards the seat occupant to provide lumbar and back support, as described above.

As shown in FIGURES 4 and 5, when the seat occupant desires less support, or no support, he or she can actuate the rocker valve to release the pressurized air to the atmosphere. When air is released from air bag 30, air bag 30 deflates which eliminates the force against seatback cushion 20 and allows seatback cushion 20 to return to its equilibrium position. Preferably, as shown in FIGURES 8 and 9, air bag 30 has a central constraint, or crease, 27 down the middle such that as air is delivered to fill air bag 30, both halves 32, 33 of air bag 30 fill with air to provide a force against each respective side of support pan 12 to allow ergonomic support to the back of a seat occupant. Such a "butterfly" configuration of air bag 30 thus allows the lumbar support actuation force to be delivered laterally displaced from the centerline of the support pan.This feature ensures full support around the entire back of the seat occupant.

Although preferably lumbar support system 25 of the present invention is actuated by means of air bag 30, it may also be actuated mechanically. Many suitable mechanical actuation devices exist which are well known to those of ordinary skill in the art and will not be discussed here. One such means is disclosed in United States Patent No. 5,299,851.

Furthermore, preferably, appendages 15 extending upward from support pan 12 are fixed relative to seatback cushion 20.

Preferably, as shown in FIGURE 2, appendages 15 are secured via a snap-fit relationship with seatback upper strut 19 in seatback cushion 20. As such, as support pan 12 is pushed inward toward seatback cushion 20, support pan 12 will travel upward as appendages 15 flex inward with support pan 12. Appendages 15 extending downward thus preferably include flanged extensions the flat surfaces of which abut and are guided by seatback lower strut 17, as shown in FIGURES 1 and 2. As will be appreciated by those of ordinary skill in the art, struts 17 and 19 may be attached to the seatback cushion or may be secured to a seat frame. Allowing support pan 12 to travel upward as it is actuated allows full actuation of lumbar support device 10 of the present invention with only a single air bag pneumatic actuation means.

Additionally, lumbar support system 25 of the present invention is preferably used in conjunction with a backrest cushion 20 contoured to accommodate the human form. Actuation of lumbar support system 25 of the present invention allows accentuation of those contours. Further, as shown in FIGURES 3 and 4, seat 28 with which lumbar support system 25 of the present invention is assembled, preferably includes a frame equipped with rigid bolster supports which help maintain the ergonomically correct contours while lumbar support device 10 of the present invention is actuated.

It will be appreciated, therefore, to those of ordinary skill in the art, that lumbar support device 10 of the present invention can be manufactured as a one-piece device with few components and few moving pieces. This construction greatly reduces assembly time and serviceability time. Lumbar support system 25 of the present invention thus provides a greater range of actuation than presently available lumbar support devices, prevents, to a greater extent, seat occupant back fatigue, and ensures greater comfort.

Of course, it should be understood that various changes and modifications to the preferred embodiments described herein will be apparent to those skilled in the art. Other changes and modifications, such as those expressed here or others left unexpressed but apparent to those of ordinary skill in the art, can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the following claims.

Claims

What Is Claimed Is:

1. A lumbar support system for a seat comprising a seatback cushion; a lumbar support positioned behind said cushion and having a generally rigid body portion, a plurality of flexible appendages extending upward and downward from the body portion; and means for moving the lumbar support body portion into the seatback cushion and causing the seatback cushion to protrude forwardly.

2. The lumbar support system of claim 1 wherein the lumbar support is vertically convex and horizontally concave.

3. The lumbar support system of claim 1 further comprising a horizontally extending support member secured relative to the seatback cushion, and at least one of the appendages terminating at a free end having a lip, said lip being secured to the support member.

4. The lumbar support system of claim 1 wherein the seatback cushion has a front surface which is vertically convex and horizontally concave.

5. The lumbar support system of claim 1 wherein the seatback cushion has a rear surface which contacts the lumbar support and which is vertically convex and horizontally concave.

6. The lumbar supporting system of claim 1 wherein the seatback cushion has a front surface and a rear surface, both surfaces being vertically convex and horizontally concave.

7. The lumbar support system of claim 1 further comprising: a seat frame; and at least one of the appendages being secured to the seat frame.

8. The lumbar support system of claim 7 further comprising a first horizontally extending support member secured to the seat frame, and at least one of either the upward-extending or downward-extending appendages terminating at a free end having a lip, the lip being secured to the first member; and a second horizontally extending support member secured to the seat frame, the other of the plurality of appendages terminating at a free end slidably engaging the second member.

9. The lumbar support system of claim 3 wherein the lip is secured to the support member in a snap-fit relationship.

10. A lumbar support system for a seat comprising a seatback cushion; a lumbar support positioned behind said cushion and having a generally rigid body portion, a plurality of appendages extending upward and downward from the body portion; and an air bag attached to the lumbar support for causing the body portion to be moved into the seatback cushion and causing the seatback cushion to protrude forwardly.

11. The lumbar support system of claim 10 wherein the air bag has a generally centrally positioned vertical constraint such that, when inflated, the air bag forms two lateral segments, each segment exerting a force on the body portion at a point laterally displaced from the center of the body portion.

12. The lumbar support system of claim 10 further comprising: a seat frame; and at least one of the appendages secured to the seat frame.

13. The lumbar support system of claim 12 further comprising a first horizontally extending support member secured to the seat frame, and at least one of either the upward-extending or downward-extending appendages terminating at a free end having a lip, the lip being secured to the first member; and a second horizontally extending support member secured to the seat frame, the other of the plurality of appendages terminating at a free end slidably engaging the second member.

14. The lumbar support system of claim 12 further comprising a rigid back plate secured to the seat frame wherein the air bag is positioned between the cushion and the plate.

15. A lumbar support system for a seat comprising a seatback cushion; a lumbar support positioned behind said cushion and having a generally rigid body portion plurality of appendages extending downward and upward from the body portion; and at least one air bag attached to the lumbar support for causing the support to be moved into the seatback cushion and causing the seatback cushion to protrude forwardly.

16. The lumbar support system of claim 15 further comprising: a seat frame; and at least one of the appendages being secured to the seat frame.

17. The lumbar support system of claim 16 further comprising a first horizontally extending support member secured to the seat frame, and at least one of either the upwardly-extending or downwardly-extending appendages terminating at a free end having a lip, the lip being secured to the first member; and a second horizontally extending support member secured to the seat frame, the other of the plurality of appendages terminating at a free end slidably engaging the second member.

18. A lumbar support for a seat comprising a generally rigid body portion being horizontally concave and vertically convex, and a plurality of substantially resilient appendages extending upward and downward from the body portion, the appendages defining substantially the same contours as the body portion and which may provide variable lumbar support.

19. The lumbar device of claim 18 wherein the support pan and appendages comprise one integral piece.

20. The lumbar device of claim 18 wherein the body portion and the appendages are plastic.

21. A lumbar support comprising: a central substantially rigid body portion being vertically convex and horizontally concave; a plurality of flexible, upward extending appendages; and a plurality of flexible, downward extending appendages.

22. The lumbar device of claim 21 wherein the support pan and appendages comprise one integral piece.

23. The lumbar device of claim 21 wherein the body portion and the appendages are plastic.

24. A lumbar support comprising: a horizontally extending substantially rigid body portion; a plurality of flexible, upward extending appendages; and a plurality of flexible, downward extending appendages; the body portion and appendages being vertically convex and horizontally concave.

25. The lumbar device of claim 24 wherein the support pan and appendages comprise one integral piece.

26. The lumbar device of claim 24 wherein the body portion and the appendages are plastic.