GB2295081A

GB2295081A - Fluid lumbar support, especially for vehicle seats

Info

Publication number: GB2295081A
Application number: GB9523085A
Authority: GB
Inventors: James Francis Nixon
Original assignee: PROTOTRIM Inc
Current assignee: PROTOTRIM Inc
Priority date: 1994-11-18
Filing date: 1995-11-10
Publication date: 1996-05-22
Also published as: CA2136153A1; GB9523085D0

Abstract

A lumbar support bladder (10) primarily for a vehicle seat (20) is contoured as a U-shaped plenum containing liquid silicone occupying approximately 65% of the volumetric space of the plenum, the balance of the plenum evacuated. The bladder is encapsulated either within the inside foam rubber bun (22) normally associated with the back of a automotive seating structure, or is an integral interior part of a seat cover assembly (21) whereupon the seat cover with bladder (10) is pulled over the foam rubber bun (22) to form the seat assembly. Once installed, the bladder (10) automatically adjusts to the anatomical condition of the seated occupant. <IMAGE>

Description

LUMBAR SUPPORT This invention relates to a lumbar support for a vehicle seat which provides variability of lumbar support pressure, irrespective of the weight or size of the seated occupant.

Various proposals have been made for a vehicle seat lumbar support. OJALA in U.S. Patent No. 4,534,593 issued 13 August, 1985 discloses a VEHICLE SEAT LUMBAR SUPPORT INSERT AND METHOD OF UTILIZING THE SAME where the support structure is encapsulated or at least overcovered by the foam padding normally found in the conventional automobile seat but his support structure is a rigid or solid piece of preferably synthetic material which is contoured to provide lumbar support; hence, it is non-yielding.

QUINTON ET AL. in U.S. Patent No. 4,718,724 issued 12 January, 1988 discloses a LUMBAR SUPPORT FOR SEAT ATTACHMENT which is adjustable but which is only a foam cushion, generally contourly shaped as a longitudinal part with a cross section resembling that of an airfoil.

Others, such as SAITO in U.S. Patent No. 4,728,148 issued 1 March, 1988 discloses a SUPPORTING STRUCTURE OF THE LUMBAR PORTION OF THE FOAM CUSHION MEMBER IN AN AUTOMOBILE SEAT which is additionally impregnated with non-soft components so as to attempt to make it more rigid.

SURBER in U.S. Patent No. 4, 738,486 issued 19 April, 1988 discloses A WATER-FILLED LUMBAR SUPPORT STRUCTURE INCLUDING WATER-FILLED SEAT PORTION AND BACK PORTION all enclosed in one or more water encapsulating bladders.

The disadvantages of the foregoing are the rigidity and the fixed formation of each of the supports, save and except that of the water-filled bladder of SURBER which does not, for very tall or heavy persons, provide adequate lumbar support force across the lumbar portion of the back when the occupant is seated.

These Froblens can be solved by a lumbar support bladder or structure consisting of a contoured bladder encapsulating a U-shaped plenum containing silicone which is suspended within the plenum under vacuum so as to occupy a substantial portion of the plenum space.

The bladder is encapsulated either within the inside foam rubber bun, normally associated with the back of an automotive seating structure, or is an integral interior part of a seat cover assembly whereupon the seat cover with bladder is pulled over the foam rubber bun to form the seat assembly. Once installed, my novel bladder automatically adjusts to the anatomical condition of the seated occupant, regardless of size or weight.

The invention therefore achieves, in combination with an automotive seating structure including a seat, a back having an outer seat cover overcovering an inside foam rubber bun, a lumbar support bladder comprising an inverted U-shaped plenum containing by volume, in excess of 50% liquid silicone, the balance of the plenum space substantially evacuated of air whereby the silicone may flow when pressured by the spine and the posterior cheeks of a person sitting against it. Preferably, the bladder is composed of EPDM rubber and bonded urethane sheet material, and the liquid plenum has the viscosity essentially that of water and occupies approximately 65% of the volumetric space of the plenum.

The invention will now be described by way of example and reference to the accompanying drawings in which: Figure 1 is a perspective view of the operational environment of the invention; Figure 2 is a front plan view of the bladder insert, according to the invention; Figure 3 is a side elevational view of Figure 2; Figure 4 is a cross sectional view of the novel lumbar support structure being a bladder showing it in a situ application, within the inside foam rubber bun, normally associated with the back of an automotive seating structure; Figure 5 is the same cross sectional view along lines 44, but only of the bladder.

Figure 6 is a cross sectional view along lines 6-6 of the bladder of Figure 2.

Figure 7 is a cross-sectional view of a seat cover with internal novel bladder which is prior to assembly over a seat foam rubber bun.

Referring to Figure 4, the novel lumbar support structure is generally indicated as (10) and is either a bag or bladder constructed from either EPDM rubber or bonded polyurethane sheet material referenced (12) defining therein a contoured plenum, generally (14) which, in front plan view, appears as the inverted letter "U". There are anchoring mounts or apertures (16) which secure the bag or bladder (10) into a seat structure, generally shown as (20) in Figures 1 and 4.

The plenum (14) is preferably 65%, by volume, filled with liquid silicone having the viscosity of water, the balance of the volume is evacuated into a vacuum region. The profile of the plenum is contoured so that the plenum has distal arms (18) positioned so that they occupy an area which generally will expand across the rear of the prolongation of the cheeks of the posterior so as to fill a void "V", being the nape of the back following the vertical prolongation, parallel to the spine, of the posterior cheeks.

The volumetric contents of the plenum (14) is such that the majority of the liquid silicone rests in the distal arms (18) and this is most clearly seen in the cross sectional Figures 4 and 5. In the preferred embodiment, the bladder is sized into a square sheet of approximately 13 inches and referring to Figure 2 and 4, the U-shaped plenum (14) has an outside width (W) of approximately 12 inches, a proximate arm width (D) of approximately 5 inches, and a distal arm length (L) of approximately 124 inches.

Cross sectional Figure 6 shows a very narrow volumetric area through the proximate arm (19) of the plenum (14).

In an alternative embodiment of the invention, and referring to Figure 7, the seat assembly (20) has an outer seat cover (21), the inner forward panel thereof having secured thereto the novel bladder (lo), as shown. The foam rubber bun (22) is assembled separately and then the seat cover assembly (21) is pulled down, in the direction of the arrows, over the bladder (22) whereupon the bottom seams sewn or fastened together and the bladder (10) is concealed within the seat assembly (20), as shown in Figure 4.

Claims

I CLAIM:

1. In combination with a. seat.

structure including a seat, a back having an outer seat cover overcovering an inside foam rubber bun, a lumbar support bladder comprising: (a) an inverted U-shaped plenum containing by volume, in excess of 50% liquid silicone, the balance of the plenum space substantially evacuated of air whereby the silicone may flow when pressured by the spine and the posterior cheeks of a person sitting against it.

2. The bladder as claimed in claim 1 comprising material selected from EPDM rubber and bonded urethane sheet material.

3. The bladder as claimed in claim 1 or 2, wherein the silicone within the plenum occupies approximately 65% of the volume thereof.

4. The bladder as claimed in claim 1, 2 or 3, including means for attaching the bladder to the inside surface of an outer seat cover overcovering the bladder.

5. The bladder as claimed in claim 1, 2, 3, or 4, wherein the silicone has the viscosity essentially that of water.

6. The bladder as claimed in claim 1, 2 3, 4 or 5, including means for attaching the bladder to the inside surface of an outer seat cover overcovering the bladder and the silicone has the viscosity essentially that of water.

7. The bladder and seat combination of any preceding claim, wherein the seat is a vehicle seat preferably an automobile seat.

8. A bladder for a vehicle seat and vehicle seat incorporating such bladder substantially as herein described with reference to and as shown in the accompanying drawings.