Lumbar support

Abstract

A lumbar support uses a molded plastic shell and a series of adjustable straps to provide a support that can be easily fitted to a user's lower back profile. A thing cushion member, preferably a cushion sleeve, is supported on the straps and does not extend to the rear portion of the plastic shell, and preferably does not extend to the sides of the shell. Air circulation channels are defined between the thin cushion member and the rear of the molded plastic shell to assist in heat removal during use of the lumbar support. This lumbar support structure is also readily modified for increased durability that different applications demand.

Description

FIELD OF THE INVENTION

The present invention relates to a lumbar support that is durable, cost effective to manufacture and has improved operating characteristics.

BACKGROUND OF THE INVENTION

Published United States Patent 2004/0104610 discloses a lumbar support device having a series of adjustable straps extending between the side portions of a molded shell. The straps extend across the shell and are adjustable in length to provide a customized fit for the back profile of a user and in particular, to provide proper support for the lumbar region of the user. The device includes a full cover over the face of the device such that the straps between the side portions of the shell are positioned and hidden behind the cover. Typically, the cover includes a foam cushion member between the straps and the cover providing an effective insulation layer and heat retention adjacent the user's back can be a problem.

Our own U.S. Pat. No. 6,971,717 discloses an improved arrangement where the straps are biased when the straps are released to automatically return the straps to an initial position in preparation for custom fitting by a user. The cover and the foam layer provide a drag on the straps returning to the initial position, such that the bias members must be relatively strong and costly.

Each of the above lumbar supports include the full cover providing a finished front face to the lumbar support as well as a finished face to the rear of the support device. In the case of our own patent, the full fitted cover provides additional resistance to the straps returned to the initial position and thus, the biasing member provided for each strap, must be relatively strong. Furthermore, the fabric cover includes an intermediate foam cushion layer, further increasing the drag and heat retention can cause some user inconvenience.

The lumbar support of the present invention provides improved durability of the device.

SUMMARY OF THE INVENTION

A lumbar support according to the present invention includes a molded plastic shell of a shallow U-shape defined by a rear portion with two forwardly extending side portions. A series of adjustable straps extend between the side portions of the molded shell adjacent a forward edge of each side portion and positioned in front of, and spaced from, the rear portion. Each strap is independently adjustable in length across the shell to allow setting thereof to accommodate setting thereof to the back profile of a user. Each strap is lockable relative to the shell to secure the strap in a set position of the user. The lumbar support includes a cushion member supported by these straps and defining a front face of the lumbar support. The lumbar support includes an open air circulation channel between the rear portion of the shell and the straps.

In a preferred aspect of the invention, the cushion member terminates inwardly of each side portion and defines side air circulation portions between the side portions of the molded shell and the cushion member.

In a further aspect of the invention, the cushion member is a sleeve with the straps passing through the sleeve.

In yet a further aspect of the invention, the sleeve includes a central seam extending across the sleeve with some of the straps positioned to one side of the central seam. Other straps positioned to an opposite side of the central seam.

In yet a further aspect of the invention, the cushioned sleeve is sized to generally correspond to the vertical dimensions between an upper strap and a lower strap of such straps.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are shown in the drawings, wherein:

FIG. 1 is a perspective view of the backrest support supported on an office chair;

FIG. 2 is a front perspective view of the backrest support;

FIG. 3 is a rear perspective view of the backrest support;

FIG. 4 is a partial perspective view of the cushioned sleeve and its cooperation with the support straps;

FIG. 5 is a partial perspective view showing securement of the straps to the rear of the shell;

FIG. 6 is a planned schematic view of the backrest support; and

FIG. 7 is a rear perspective view showing the clamping mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The lumbar support 2 shown in FIG. 1 is placed on an office chair 80 and is retained adjacent the back of the office chair by means of a retaining strap 40. The lumbar support 2 includes a molded shell 4 having a rear portion 6 and side portions 8 and 10 supporting the rear portion at a raised position. Each of the side portions extend forwardly of the rear portion and include support legs 12 and 14. With this arrangement, the support legs are positioned either side of the open central portion 16 below the rear portion 6. This basically provides additional space to accommodate the user's buttocks in close proximity to the cushioned back portion of the office chair or an upright back of a different chair like support structure.

The straps 20 are adjustable in length to allow a user to set each of the straps at a particular length to provide the necessary customized support for the user's lower back profile. The straps are essentially non elastic to provide firm support at the desired position. The straps are of a fixed non yielding length across said shell when the straps are secured in a fitted configuration.

The straps as shown in FIG. 5 include an elastic portion 50 that provides a return bias force when the locking buckle 40 is released. The releasing of the buckle as shown in FIG. 7 allows the strap to return to a drawn initial position across the face of the shell. The user can then set the appropriate length of the strap by pushing his lower back into the lumbar support and assuming a correct posture position at which time the particular lengths of the straps can be locked by the individual buckles. At that point, the elastic bias member 50 of each strap no longer affects the straps secured between the two side portions.

In the embodiment as shown in FIG. 2, four straps 20 are placed across the base of the shell and the straps are exposed either side of a cushioned sleeve 22. This cushion sleeve 22 preferably floats or is slidable on the straps 20 and is generally positioned in a central portion at the front face of the molded shell 4. The purpose of the cushion sleeve is to provide some cushioning of the user's back when he forces the same against the support straps 20. This cushion sleeve does not extend over to the shell and an air circulation channel 30 is provided between the rear portion 6 of the molded shell 4 and the cushioned sleeve 22. This air circulation channel helps to reduce heat buildup at the user's back. Furthermore, the cushion sleeve 22 preferably terminates short of the sides of the molded channel and thus, the ends of the cushion sleeve are exposed as well as several inches of the straps 20 adjacent the sides of the shell. With this arrangement, air can also circulate from the sides of the shell towards the center, further improving the dissipation of heat.

The cushion sleeve 22 preferably includes a central seam 24 with two of the straps 20 being retained in an upper passageway 26 of the sleeve and two straps retained in a lower passageway 28 of the sleeve. This arrangement allows the straps 20 to support the cushion sleeve 22 and generally retain this cushion sleeve in a central position. The straps can essentially freely pass through the sleeve to allow adjustment. The sleeve essentially slides on the support straps and allows the straps to be set at different lengths. This slide support allows length adjustment to occur at one side of the lumbar support. The cushion sleeve preferably includes a fabric type outer face and a thin foam back. Different sleeves can be used for different applications such as indoor versus outdoor appliances.

The lumbar support as shown in FIG. 2 includes the molded shell 4 which can be of a durable plastic material with a series of adjustable straps 20, also of a durable, non stretch material such as a nylon web material, in combination with the cushion sleeve 22. This can also be of a durable material whereby the resulting lumbar support is also appropriate for many outdoor applications, for example, sporting events, boat seat applications such as applications where the lumbar support may be exposed to the elements.

The lumbar support as described with respect to FIG. 2 is cost effective to manufacture and the use of the cushion sleeve also provides a simple mechanism to allow the movement of the straps 20 within the sleeve. This is an important aspect in that each of the straps 20, as shown in FIGS. 5 and 6, is secured at a rear face of the lumbar support. Each strap 20 includes a first fastening end 52 that receives one arm of the rigid “U” shaped member 54. The elastic bias member 50 of the opposite end of the strap engages the other arm of the “U” shaped member.

The “U” shaped member 54 has a snug interference type fit with the securing lug 56 formed in the rear of the shell. In addition, the “U” shaped member 54 is effectively trapped between the opposed stiffening channels 58 and 60. Thus, the “U” shaped member 54 in cooperation with the lug 56 provides an effective simple means for securing of the strap to the shell. When a user presses on a strap 20 with the strap effectively locking by a buckle 59 at one side of the shell, the “U” shaped member 54 in cooperation with the lug 56, secure the opposite end of the strap. When the buckle is released, the elastic biased member 50 draws the strap to a partially drawn state across the face of the shell and defines an initial position to allow a user to adjust the length of the straps.

FIG. 6 also illustrates the central air circulation channel 30 which allows movement of air vertically between the cushion sleeve 22 and the rear portion 6 of the shell, as well as the side air channels shown as 70 and 72 at opposite ends of the cushion sleeve 22. This air circulation at the rear of the cushion sleeve 22 allows cool air at the user's back and renders the support more comfortable for longer periods of time.

A further advantage of the lumbar support, in addition to the improved durability and improved air circulation, is the immediate understanding of how the device is to be used by a user. The exposed straps either side of the cushion sleeve 22 and the exposed buckles on the rear surface of the shell, allow a user to easily understand how the device operates. With the prior art arrangements, the full cover provided on the lumbar support hid the working components and, a user did not necessarily appreciate the ease of adjustment or the different principles of operation of the support. With a full cover, a user mistakenly assumed the lumbar support had the traditional foam cushion insert.

With the exposed straps and simplified cushion member, a user readily appreciates the functionality of the device and is more likely to consider the purchase of the device. Furthermore, the manufacturing costs have been significantly reduced with improved operational characteristics.

The lumbar support with the series of adjustable straps is the preferred structure but other support substrates can be used, including substrates that have some elasticity. The air circulation channel or channels would still reduce heat build up and make the support more convenient to use. The floating cushion support is optional but preferred.

Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims

1. A lumbar support comprising a molded plastic shell of a shallow “U” shape defined by a rear portion and two forwardly extending side portions; said molded plastic shell including a series of adjustable straps extending between said side portions adjacent a forward edge of each side portion and positioned in front of and spaced from said rear portion; each strap being independently adjustable in length across said shell to allow settings thereof to a lower back profile of a user; each strap being releasably fixable to said shell to define a strap in a set position of the user; said lumbar support including a cushion member supported by said straps and defining a front face of said lumbar support; and wherein said lumber support includes an open air circulation channel intermediate said rear portion of said molded plastic shell and said straps.

2. A lumbar support as claimed in claim 1 wherein said cushion member terminates inwardly of each side portion defining side air circulation portions between said side portions of said molded plastic shell and said cushion member.

3. A lumbar support as claimed in claim 2 wherein said cushion member is a sleeve with said straps passing through said sleeve.

4. A lumber support as claimed in claim 3 wherein said sleeve includes a central seam extending across the sleeve with some of said straps positioned on one side of said central seam and some of said straps positioned on an opposite side of said central seam.

5. A lumber support as claimed in claim 3 wherein said cushion sleeve is of a size to generally correspond to a vertical spacing between an upper strap and a lower strap of said straps.

6. A lumbar support comprising a molded plastic shell of a shallow “U” shape defined by a rear portion and two forwardly extending side portions; said molded plastic shell including an adjustable support substrate extending between said side portions adjacent a forward edge of each side portion and positioned in front of and spaced from said rear portion; said adjustable support substrate allowing adjustment to conform to a lower back profile of a user; and wherein said lumber support includes an open air circulation channel intermediate said rear portion of said molded plastic shell and said adjustable support substrate.

7. A lumbar support as claimed in claim 6 wherein said adjustable support substrate includes a cushion portion supported in front of said support substrate.

8. A lumbar support as claimed in claim 7 wherein said cushion portion terminates inwardly of each side portion to define side air circulation portions between said side portions of said molded plastic shell and said cushion portion.

9. A lumbar support as claimed in claim 7 wherein said cushion portion is a sleeve with said support substrate passing through said sleeve.