Apparatus for the Attachment of a Lower Back Support Upholstery to a Chair

The invention relates to an apparatus for the attachment of a back rest support upholstery to a chair.

In a known apparatus of the above-mentioned type, the back rest has a back rest support manufactured from a bar, in the manner of a bow spring. A back rest support carrier, which is also made of spring steel and to which the lower back support upholstery is connected, is arranged between the shanks of the back rest support, so that it can yield essentially independently of the back rest in a horizontal direction. See U.S. Pat. No. 3,059,971.

The object of the present invention is to create an apparatus in which the lower back support upholstery can be attached in a simple fashion to the chair back rest in an elastically resilient manner. This object is achieved according to the invention by means of a spring arranged indirectly between a back rest support of the chair back rest and the back rest support upholstery. The provided attachment saves space and is independent of the design of the back rest support, which can also be rigid.

An object of the invention is to assure a sturdy apparatus which acts to hinder a rotation of the lower back support upholstery about an axis which is arranged essentially vertically to the back rest support and runs above the seat of the chair.

Another object of the invention is to provide a tilting lever for the acting of a force on the upper end of the lower back support upholstery, by which means the lower back support upholstery can deflect, particularly at its upper side.

Yet another object of the invention is to make possible a simple attachment of the spring to the lower back support upholstery.

With the foregoing and other objects, advantages and features of the invention that will become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims and to the several views illustrated in the attached drawings.

FIG. 1 is a cross-section along the line I--I in FIG. 2, showing a portion of a chair illustrated schematically as an exemplary embodiment of the invention.

FIG. 2 is a cross-section according to the line II--II in FIG. 1 in which the elements lying in front of the section plane are illustrated with broken lines.

FIG. 3 is a top view in the direction of the arrow A in FIG. 1.

In the center of a cross support 1, which is pivotable about a horizontal axis, is attached an essentially perpendicular back rest support 2. Both supports consists of a tube which is rectangular in cross section. Identical springs 3 through 5, which are arranged in a triangular and are formed as rubber-metal elements, are each attached to the back rest support 2 by means of respective screws 6, which penetrate a wall of the back rest support and are screwed into the adjacent metal portion of the associated spring with a washer arranged between the screw heads and the back rest support. In order to provide access to the screws 6, the back rest support has an access hole 7 in its opposite wall. The metal element provided on the other side of the spring supports a threaded bolt 8, which is screwed into a tubular element 9, which, in turn, is arranged on the back side of a lower connecting piece 10 of a holder 11 for a lower back support upholstery (not shown). This lower back support upholstery is arranged on the other side of the back rest support 2 and is inserted into the ends of the holder 11. Viewed from above, the holder 11 and the lower back support upholstery give the back rest support 2 the shape of a narrow rectangle, the longitudinal sides of which are bowed.

As illustrated in FIG. 2, the three springs 3 through 5 are arranged in the shape of an isosceles triangle, whereby the upper, longer side runs horizontally. These springs alone support the lower back support upholstery together with the holder 11. The lower back support upholstery extends, like the holder 11, over the width of the chair seat and has upholstery on the side facing the chair seat. The abutting ends of the holder 11 and the lower back support upholstery are bent backwards.

The springs 3 through 5 make it possible for the lower back support upholstery to yield in a horizontal direction, to perform a tilting movement and also make possible a limited resiliency in a perpendicular direction. When the user of a seat provided with the apparatus described herein rests against the lower back support upholstery, the springs 3 through 5 are loaded in tension.

Although only preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.