Adjustable backrest

Details Adjustable backrest Adjustable backrest

1996-01-22

1997-04-29

Brown, Peter R.

Chairs and seats

Supplemental back

Including a means to adjust supplemental back relative to a...

2972844, 2972847, A47C 746

Patent

active

056241585

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates in general to backrests, and more particularly an adjustable backrest having independent adjustment of lumbar and upper back height and curvature, as well as overall height adjustment to fit different size patients.


BACKGROUND OF THE INVENTION

Adjustable backrests or supports are well known in the art. U.S. Pat. No. 5,112,106 (Asbjornsen et al) discloses a backrest comprising a central spine or rail to which a lumbar support cushion and head cushion are connected via a sliding element. The sliding element is connected to the rail or spine via a ratchet-like connection. The '106 Patent is of interest for teaching the concept of height adjustable lumbar support where the adjusting means is connected to a spine for sliding engagement therewith.
U.S. Pat. No. 2,756,809 (Endresen) discloses a back support comprising a metal sheet with adjustable lumbar and upper-back portions. A screw adjusts the concavity of the upper-back portion while a further screw adjusts the convexity of the lumbar support portion. A pair of cross bars are provided for supporting and securing the lumbar and upper back portions of the sheet to the backrest. The two adjustment screws are mounted on a pair of sliding plates to provide vertical adjustment of the lumbar support area and the upper-back support area. Accordingly, this patent is of interest for teaching independent height and curvature adjustment of the lumbar support and upper-back support portions of a backrest.
Additional references are known which pertain to adjustable back support or backrests, as follows: U.S. Pat. Nos. 2,843,195; 3,241,879; 3,762,769; 4,153,293; 4,452,458; 4,541,670; 4,601,514; 4,632,454; 4,722,569; 4,909,568; 4,915,448; 4,968,093; 5,026,116; and 5,197,780, as well international patent application No. PCT/AU91/00487 (BackCare and Seating Pty. Ltd.).
While the known prior art backrests disclose the provision of lumbar and upper-back support members with independently adjustable curvature and positioning, none of the known prior art teaches the combination of height adjustment, lumbar height, curvature and position adjustment and side-to-side mobility. Nor does the prior art teach this combination with upper back curvature adjustment. The provision of these features in a backrest is important to ensure proper fitting of the backrest for adult bodies of different height and shapes. Furthermore, human beings tend not to be static but like to move or "fine tune" their sitting positions. The known prior art backrests do not provide adequate side-to-side mobility for such movement. Nor do they allow for the convenient minor adjustment of support. In addition, the known prior art back supports are generally bulky or heavy to carry and occupy excessive space at the bottom portions thereof, thereby leaving very little room to sit on a chair.


SUMMARY OF THE INVENTION

According to the present invention, a backrest is provided in which lumbar height and curvature adjustment are provided along with overall height adjustment to fit different sized persons. Side-to-side mobility is provided to accommodate twisting movements of the human back which are common when a person is sitting (e.g. turning to reach something, or "fine tuning" of one's sitting position). Furthermore, according to the backrest of the present invention a slight hollow is provided just above the base of the backrest to allow for curvature and space so that the backrest does not occupy excessive space on a chair. Additionally, in one embodiment upper-back curvature and height adjustment are provided along with side adjustment to suit each half side of the human back (i.e. for accommodating different torso shapes).


BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the backrest according to a first embodiment of the present invention resting on a chair;
FIG. 2 is a cross section along lines II--II of FIG. 1;
FIG. 3 is a rear perspective view of the backrest according to the present invention;
FIGS. 4A and 4B are cross sectiona

REFERENCES:
patent: D214119 (1969-05-01), Worley
patent: D345477 (1994-03-01), Infanti
patent: D345478 (1994-03-01), Infanti
patent: D358515 (1995-05-01), Adat et al.
patent: 2756809 (1956-07-01), Endresen
patent: 2843195 (1958-07-01), Darvaeus
patent: 3112137 (1963-11-01), Drenth
patent: 3241879 (1966-03-01), Castello et al.
patent: 3608960 (1971-09-01), Sherman
patent: 3762769 (1973-10-01), Poschl
patent: 4153293 (1979-05-01), Sheldon
patent: 4321044 (1982-03-01), Kron
patent: 4452458 (1984-06-01), Schueter
patent: 4502728 (1985-03-01), Sheldon et al.
patent: 4535495 (1985-08-01), Oldfield
patent: 4541670 (1985-09-01), Morgenstern et al.
patent: 4601514 (1986-07-01), Meiller
patent: 4632454 (1986-12-01), Neart
patent: 4647066 (1987-03-01), Walton
patent: 4722569 (1988-02-01), Morgenstern et al.
patent: 4909568 (1990-03-01), Dal Monte
patent: 4915448 (1990-04-01), Morgenstern
patent: 4965093 (1990-10-01), Dal Monte
patent: 4981325 (1991-01-01), Zacharkow
patent: 4993164 (1991-02-01), Jacobsen
patent: 5026116 (1991-06-01), Dal Monte
patent: 5050930 (1991-09-01), Schuster
patent: 5112106 (1992-05-01), Ashjornsen
patent: 5197780 (1993-03-01), Coughlin
patent: 5228747 (1993-07-01), Greene
patent: 5286083 (1994-02-01), Mattison
patent: 5314235 (1994-05-01), Johnson
patent: 5344211 (1994-09-01), Adat et al.

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