Lumbar Support

The subject invention relates to an adjustable support assembly for use in the backrest of a seat, and, more particularly, to a pneumatically adjustable lumbar support allowing the passenger of a motor vehicle to adjust the seat back cushion to desired contour.

Conventionally, lumbar support assemblies are used for maintaining a seat cushion in a contoured position. Such lumbar support assemblies usually include either bellows, air bladder or a pump to force air into the cushion pocket to reach a desired contour.

British Patent Number 1,299,789 discloses an adjustable self inflated support cushion with an air impermeable exterior shell which surrounds an open self foamed material. Further, U.S. Pat. No. 4,516,568 to Baxter et al discloses yet another pressure exerting device comprising a resilient wedged shape member and modified U-shaped air bladder which may be filled to selected air pressures. However, these systems of lumbar adjustment are inadequate as they are sensitive to temperature change thus rendering adjustment hard to achieve. Moreover, foam tends disintegrate with wear over time, thus, decreasing contour effect. And none have a normal state with the bladder in the inflated state without air pressure being applied.

The subject invention is an assembly including a seat having a seat frame and backrest. The assembly comprises a mounting member for mounting to a seat frame and a pneumatic adjustment means supported on the mounting member for moving between inflated and deflated states. The assembly also includes control means for controlling movement of the pneumatic adjustment means between the inflated and deflated states with the control means characterized by including back support means independently supported on the mounting member and extending over the pneumatic adjustment means for biasing the pneumatic adjustment means toward the inflated state and moving inwardly toward a deflated state in response to a passenger to an infinitely adjustable contour.

Accordingly, the present invention provides durable back support means having a flexible contoured plate with a free state contour which maintains the pneumatic adjustment means in an inflated state forming the backrest while forming the backrest in a maximum outwardly contoured position. Hence, inflation of the pneumatic adjustment means will not be dependent on temperature. Likewise, foam is not required in order for inflation of the pneumatic adjustment means to occur since the back support means necessarily will try to maintain its inflated free state position. Additionally, the contoured plate provides for sturdy back support means, thus allowing manufacturers to vary the thickness of the seat cushion as desired to provide for a more comfortable seat.

Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 a perspective view partially broken away and in cross section of the preferred embodiment of the subject invention within the seat frame;

FIG. 2 is a perspective view of the assembly of the preferred embodiment of FIG. 1 without the foam seat cushion;

FIG. 3 is a perspective view of the pneumatic adjustment means in an inflated state;

FIG. 4 is a perspective view of the pneumatic adjustment means in the deflated state;

FIG. 5 is a fragmentary cross sectional view of the preferred embodiment of the subject invention;

FIG. 6 is a cross section of the control means attached to the pneumatic adjustment means;

FIG. 7 is a perspective view of an alternative embodiment;

FIG. 8 is a fragmentary perspective view of a coupler means of the alternative embodiment of FIG. 7; and

FIG. 9 is a cross section of yet another alternative embodiment.

Referring to the Figures wherein like numerals indicate like or corresponding parts throughout the several views, a lumbar support assembly 10 is shown in FIG. 1 for a seat 12 including a seat frame 14 on a backrest 16 including a seat cushion 17. The assembly 10 shown in FIG. 2 includes a mounting member 18 for mounting to the seat frame 14. A pneumatic adjustment means 20 is supported on the mounting member 18 and includes a control means 22 for controlling movement of the pneumatic adjustment means 20 between inflated and deflated states. A back support means 24 is supported on the mounting member 18 which extends over and biases the pneumatic adjustment means 20.

The mounting member 18 includes suspension means 26 for supporting the mounting member 18 on the seat frame 14. The suspension means 26 includes a plurality of springs 28 as shown in FIGS. 2 and 5. The springs 28 extend outwardly from and are spaced about the periphery of the mounting member 18 for supporting the mounting member 18 on the seat frame 14. The mounting member 18 further includes a plurality of rectangular, or more particularly U-shaped, guides 30 as shown in FIG. 2.

The pneumatic adjustment means 20 comprises an accordian-like shaped impermeable bladder 32. FIGS. 3 and 4 show the bladder 32 in inflated and deflated states respectively. A tube 34 is in fluid tight communication with the bladder 32 for directing air into and out of the pneumatic adjustment means 20.

Referring to FIGS. 1, 2 and 6, the control means 22 is shown. The control means 22 includes a control valve 36, shown in FIG. 6, in fluid communication with the tube 34 for controlling the flow of air into and out of the pneumatic adjustment means 20. A biasing means 38 is provided within the control means 22 for continuously urging the control valve 36 to the closed position preventing the passage of air through the tube 34. The control means 22 also includes a clip 40 as shown in FIG. 6 allowing easy attachment of the control valve 36 to the seat 12.

The back support means 24 as in FIGS. 1 and 2, is shown to include a flexible contoured plate 42 having a free state contour to maintain the pneumatic adjustment means 20 in an inflated state thus forming the backrest 16 in the maximum outwardly contoured position. The contoured plate 42 has a bulged middle portion spaced from the mounting member 18 and extends between upper 44 and lower 46 ends having at least one of the upper 44 and lower 46 ends supported on the mounting member 18.

The bulged middle portion of the contoured plate 42 is coupled to the pneumatic adjustment means 20 by coupler means 48 preferably through the use of VELCRO, i.e., a nylon material made with both a surface of tiny hooks and a complementary surface of an adhesive pile used in matching strips that can be pressed together and pulled apart for easy fastening and infastening, but not limited thereto. The coupler means 48 also couples the pneumatic adjustment means 20 to the mounting member 18. Therefore, the pneumatic adjustment means 20, the contoured plate 42, and the mounting member 18 are fastened together as an operational unit by the coupler means 48.

A lost motion connector means 50 slideably connects one of the upper 44 and lower 46 ends of the contoured plate 42 to the mounting member 18 as shown in FIGS. 3, 4 and 5. It should be understood that either of the upper 44 or lower 46 ends of the contoured plate can be connected or supported on the mounting member 18, but in the preferred embodiment illustrated in FIGS. 1-5, the upper end 44 of the contoured plate 42 is connected to the mounting member 18 by the lost motion connector means 50. The assembly 10 further includes attachment means 52 for attaching the lower end 46 of the contoured plate 42 to the mounting member 18 to prevent vertical movement of the lower end 46 relative to the mounting member 18. More specifically, the attachment means 52 includes a plurality of semicircular hooks 54 extending from the mounting member 18. The hooks 54 rotatably support the lower end 46 of the bulged contoured plate 42 to the mounting member 18 while preventing linear movement therebetween, i.e., preventing any movement parallel to the mounting member 18. A plurality of rectangular fingers 56 on the contoured plate 42 operatively engage with the lost motion connector means 50 provided on the upper end 44 of the bulged contour plate 48. The fingers 56 on the contoured plate 42 are slideably disposed within the plurality of guides 30 connected to the mounting member 18.

In operation, the subject invention provides a simple yet durable and effective lumbar support assembly 10. Referring to FIGS. 4 and 5, the bladder 32 is shown in a fully inflated state, thus yielding the maximum outward projection from the backrest 16. It is probable that this maximum outward projection will be uncomfortable for most persons sitting in the seat 12, and therefore inward adjustment will be required. To accomplish such inward adjustment, the user first depresses the button of the control valve 36 against the biasing means 38, thereby aligning the passage in the button with the tube 34. While still depressing the button of the control valve 36, the user exerts a compressive force against the lumbar support assembly 10, such as by leaning rearwardly against the seat backrest 16. This compressive force tends to flatten the bulged central portion of the contoured plate 42 toward the mounting member 18, thereby compressing and deflating the bladder 32 disposed inbetween. Deflation of the bladder 32, in turn, forces air out of the bladder 32 and through the tube 34, which eventually passes through the passage in the button of the control valve 36 and into the ambient environment.

Once the user has achieved a comfortable adjusted position of the assembly 10, the button of the control valve 36 is released thus moving the passage in the button out of communication with the tube 34 and thereby sealing the tube 34 from communication with the ambient environment. This prevents the bladder 32 from either inflating or deflating until the control valve 36 is once again actuated. With the control valve 36 now in its normally closed state, the contoured plate 42 is locked, or frozen, in a semi-flattened position due to its coupling to the bladder 32, which, in turn, is coupled to the mounting member 18. Hence, the lumbar support assembly 10 is maintained in an adjusted state so long as the control valve 36 remains closed, as shown in FIG. 4.

If a user of the seat 12 should desire to adjust the lumbar support assembly 10 back to its maximum outward projection, the user simply depresses the button of the control valve 36, thus aligning the passage in the button with the tube 34. Because the contoured plate 42 has a natural bow, or memory, the contoured plate 42 urges, or pulls, the bladder 32 to a fully inflated condition, thus causing air to be drawn into the bladder 32 through the tube 34 and the control valve 36. If the bladder 32 were not fastened to both the mounting member 18 and the contoured plate 42, the bladder 32 would not automatically reinflate as the contoured plate 42 moved back to its natural, free state, maximum outward projection. Likewise, if the bladder 32 were not fastened to both the mounting member 18 and the contoured plate 42, then the contoured plate 42 would not remain in a semi-flattened position after inward adjustment by the user as described above.

Hence, it will become apparent that a primary advantage of the subject lumbar support assembly 10 is that the user of the seat 12 supplies the energy for adjusting the assembly 10 inwardly only. Outward adjustment of the assembly 10 is accomplished automatically by way of the contoured plate 42, with the bladder 32 serving merely to lock, or retain, the contoured plate 42 in any desired position to which the user moves it.

The embodiment of FIG. 7 shows an alternative suspension means 26 comprising a plurality of integral clips or arms 58 spaced about the periphery of the mounting member 18 for supporting the mounting member 18 on the seat frame 14.

This embodiment also includes an alternative coupler means 48 including slots 60 and fasteners 61. The slots 60 are disposed in the mounting member 18 and have enlarged ends for receiving the heads of the fasteners 61 which slideably fit within elongated slots 60 disposed in the mounting member 18. Therefore, the fasteners 61 disposed in the slots 60 are effective for slideably connecting the pneumatic adjustment means 20 to the mounting member 18 as the pneumatic adjustment means 20 moves between the inflated and deflated states.

The embodiment of FIG. 9 shows a variation for supporting the contoured plate 42' on the mounting member 18. The contoured plate 42' extends in a horizontal direction from end-to-end instead of vertically. Slider means 62 is provided for unconnected sliding movement of the contoured plate 42 relative to the mounting member 18. The slider means includes rounded ends 62 for slideably supporting the contoured plate 42' on the mounting member 18. That is, the rounded ends 62 provide unconnected sliding movement of the contoured plate 42' relative to the mounting member 18. The ends 62 of the contoured plate 42' will slide and the bow thereof moves inward as the bladder (32) moves toward deflated state, and vice versa.

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.