Backrest

• US 6,971,717 B1
• Filed: 06/17/2004
• Issued: 12/06/2005
• Est. Priority Date: 06/17/2004
• Status: Expired due to Fees

• Current Assignee: IWI Incorporated
• Original Assignee: IWI Incorporated
• Inventors: Rhodes, Paul
• Primary Examiner(s): Cranmer, Laurie K.
• Application Number:
  US10/868,864
• Publication Number:
  US 20050280306A1
• Time in Patent Office: 537 Days
• Field of Search: 297/230.1, 297/230.11, 297/230.14, 297/452.63
• US Class Current: 297/230.1
• CPC Class Codes: A47C 7/46 with special, e.g. adjustable , lumbar region support profile; "Ackerblom" profile chairs

Abstract

An adjustable backrest has a series of adjustable straps extending across a front opening cavity of a backrest support. The straps are held in a locked, fitted position by a series of buckles at one side of the backrest which engage and lock the straps. Each strap is acted on by a bias arrangement and urges the straps to a drawn position across the front open cavity. This drawn position is an initial setup position that allows fitting of the backrest for a particular user.

Claims

1. A backrest comprising:

a molded support having a generally “

U”

shaped cross section with a plurality of adjustable straps attached to said molded support and extending across said “

U”

shaped cross section with each of the plurality of straps being adjustable to allow the strap to partially move into said “

U”

shaped section;

each strap is attached to said molded support and extends through a buckle arrangement provided on a rear face of said molded support;

each buckle arrangement is movable between a release position allowing adjustment of the length of strap across the “

U”

shaped section and a locked position, where the strap is locked, relative to the buckle arrangement;

each strap also includes a bias arrangement automatically urging each strap in a direction to draw the strap across said “

U”

shaped section to an initial set position when the respective buckle arrangement is in a release position.

2. A backrest support as claimed in claim 1, wherein said bias arrangement is attached to a rear surface of said molded support and acts on a portion of each strap located on said rear surface after the strap has passed through the buckle arrangement.

3. A backrest support as claimed in claim 1, wherein one end of each strap is connected to a rear surface of said molded support, and an opposite end of said strap passes through said buckle arrangement.

4. A backrest support as claimed in claim 3 wherein said bias arrangement is a series of independent bias members, each associated with one of said straps.

5. A backrest support as claimed in claim 4 wherein each independent bias arrangement is an elastic member with one end thereof attached to one end of the respective strap and an opposite end of the elastic member held in a fixed position relative to said molded support.

6. A backrest support as claimed in claim 5, wherein each strap and each independent bias member is attached to said rear surface of said molded support.

7. A backrest comprising:

a molded support;

a series of adjustable straps extending across said molded support;

a releasable lock means for engaging each strap and maintaining a set relationship of the strap, relative to said molded support when said lock means is in a lock position;

each strap including a bias arrangement for urging the strap towards an initial set position, where the strap is drawn across a front cavity of said molded support when said releasable lock means is released, and said strap is able to move relative to the releasable lock means.

8. A backrest support comprising a molded support a series of adjustable straps extending across said molded support;

a releasable lock means for engaging each strap and maintaining a set relationship of the strap, relative to said molded support when said lock means is in a lock position;

said molded support defining a “

U”

shaped cavity with a series of reinforcing ribs extending across at least a base of the “

U”

shaped cavity; and

said molded support having on a rear surface of the base of said “

U”

shaped cavity a series of channels with each strap being secured within one of said series of channels.

9. A backrest support comprising a molded support a series of adjustable straps extending across said molded support;

a releasable lock means for engaging each strap and maintaining a set relationship of the strap, relative to said molded support when said lock means is in a lock position;

said molded support defining a “

U”

shaped cavity with a series of reinforcing ribs extending along the “

U”

shaped cavity; and

said molded support having on a rear surface of said “

U”

shaped cavity a series of channels with each strap being secured within one of said series of channels wherein said “

U”

shaped cavity includes two downwardly extending support legs with the support legs being positioned either side of said “

U”

shaped cavity.

10. A backrest support as claimed in claim 9 wherein said support legs are outwardly and rearwardly resiliently deflectable.

11. A backrest support as claimed in claim 10 wherein said “

U”

shaped cavity is stiff relative to said support legs in normal operating conditions of said backrest support.