Chair having adjustable synchronous tilting

• US 5,931,531 A
• Filed: 09/21/1998
• Issued: 08/03/1999
• Est. Priority Date: 01/23/1997
• Status: Expired due to Fees

• Current Assignee: Comforto GmbH
• Original Assignee: Comforto GmbH
• Inventors: Assmann, Jorg
• Primary Examiner(s): Cuomo, Peter M.
• Assistant Examiner(s): BARFIELD, ANTHONY DERRELL
• Application Number:
  US09/157,878
• Time in Patent Office: 316 Days
• Field of Search: 297/316, 297/320, 297/300.1, 297/300.2, 297/300.3, 297/300.8, 297/301.6, 297/301.7, 297/300.4, 297/300.5, 297/300.6, 297/300.7, 297/340
• US Class Current: 297/316
• CPC Class Codes: A47C 1/03255 with a central column, e.g. rocking office chairs
• CPC Class Codes: A47C 1/03294 slidingly movable in the base frame, e.g. by rollers

Abstract

A chair having adjustable synchronous tilting, where a seat (7) pivotable about a seat pivot axis (5) and a back-rest support (11) pivotable about a back-rest pivot axis (9) are coupled by a coupling link (15) for simultaneous inclination changes, the synchronous tilting ratio, i.e. the ratio of the coupled inclination changes of seat and back-rest can be changed and individually adjusted, for example by displacing the engagement points of the coupling link (15) at the seat (7) and the back-rest support (11), respectively.

Claims

1. A chair having adjustable synchronous tilting, comprising:

a base support;

a seat having a means for pivotably mounting said seat to said base support about a horizontal seat pivot axis, said seat having a normal position and a tilted position which define a first pivot angle, said seat having at least one guide means that is substantially horizontal when said seat is in said normal position;

a back rest support having a means for pivotably mounting said back rest support to said base support about a horizontal back rest support pivot axis, said back rest support having a normal position and a tilted position which define a second pivot angle, said back rest support having at least one guide means that is substantially horizontal when said back rest support is in said normal position;

wherein a synchronous tilting ratio is defined by the ratio between said first pivot angle and said second pivot angle;

a back rest which is attached to said back rest support;

at least one coupling link means, each said coupling link means having an upper pivot engaging at least one said seat guide means, said upper pivot being displaceably guided in said seat guide means, and a lower pivot engaging at least one said back rest support guide means, said lower pivot being fixed in relation to said upper pivot and displaceably guided in said back rest support guide means;

at least one adjusting means for displacing and fixing a position of said coupling link upper pivot along said seat guide means and said coupling link lower pivot along said back rest support guide means; and

a means for urging said seat and said back rest support toward said normal position from said tilted position;

wherein said synchronous tilting ratio is adjustably determined by the displacement of said seat pivot axis and said back rest support pivot axis from said coupling link upper pivot engagement and said coupling link lower pivot engagement, respectively, as established by said adjustment means.

2. A chair having adjustable synchronous tilting as in claim 1, wherein:

said adjustment means, said seat guide means and said back rest support guide means are chosen to provide a range of displacement of said coupling link upper pivot along said seat guide means and said coupling link lower pivot along said back rest support guide means relative to said seat pivot axis and said back rest support pivot axis so that said synchronous tilting ratio is 0.4;

1 at one end of said displacement range and 0.7;

1 at the other end of said displacement range.

3. A chair having adjustable synchronous tilting, comprising:

a base support;

a seat pivotably mounted to said base support about a physical or imaginary horizontal seat pivot axis, said seat having a normal position and a tilted position which define a first pivot angle, said seat having at least one slot that is substantially horizontal when said seat is in said normal position;

a back rest support pivotably mounted to said base support about a physical or imaginary horizontal back rest pivot axis, said back rest support having a normal position and a tilted position which define a second pivot angle, said back rest support having at least one slot that is substantially horizontal when said back rest is in said normal position;

wherein a synchronous tilting ratio is defined by the ratio between said first pivot angle and said second pivot angle;

a back rest which is attached to said back rest support;

at least one coupling link, each said coupling link having an upper pivot engaging at least one said seat slot, said upper pivot being displaceably guided in said seat slot and a lower pivot engaging at least one said back rest support slot, said lower pivot being fixed in relation to said upper pivot and displaceably guided in said back rest support slot; and

at least one adjusting means for displacing and fixing said coupling link upper pivot along said seat slot and said coupling link lower pivot along said back rest support slot;

wherein said synchronous tilting ratio is determined by the displacement of said seat pivot axis and said back rest support pivot axis from said coupling link upper pivot engagement and lower pivot engagement, respectively, as established by said adjustment means.

4. A chair having adjustable synchronous tilting as in claim 3, wherein:

said adjusting means comprises a lead screw assembly.

5. A chair having adjustable synchronous tilting as in claim 3, wherein:

said adjustment means, said seat slot and said back rest support slot are chosen to provide a range of displacement of said coupling link upper pivot along said seat slot and said coupling link lower pivot along said back rest support slot relative to said seat pivot axis and said back rest support pivot axis so that the synchronous tilting ratio is 0.4;

1 at one end of said displacement range and 0.7;

1 at the other end of said displacement range.