Patent US4666121A successfully refreshed from Google Patents.
US4666121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spring-tilt mechanism for a chair or seat
Assignee: President Office Furniture Ltd
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Filing: 1986-05-12
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Granted: 1987-05-19
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Expires: 2006-05-12
Abstract
Abstract The spring-tilt mechanism comprises a support frame (4), a seat portion (1) tiltable on the support frame (4) about a substantially horizontal axis (2) between a first and a second position, e.g. defined by stops (13, 13'). One end (15') of a torsion spring (15) is fixed against rotation in the support frame (4). A gear box (16) is operatively engaged with the other end (15") of the torsion spring (15) and has an extendible member (24) engageable with a tracking surface (31) of the seat portion (1). An operating member (29) on the gear box (17) is easily accessible to a user sitting on the seat portion (1) to pre-load the torsion spring (15) for cushioning the user on the seat portion (1) between the said first and second positions (stops 13, 13').
Inventors
- 👤 John Choong
- 👤 Geoffrey Hollington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:21
CPC Classifications
A; A47; A47C; A47C3/00; A47C3/02; A47C3/025; A47C3/026; A47C7/00; A47C7/36; A47C7/40; A47C7/44; A47C7/441; A47C7/445; A47C7/4454
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
126 words
A spring-tilt mechanism for a chair or seat comprising a support frame, a seat portion tiltable on the support frame about a substantially horizontal axis between a first and a second position, a torsion spring having two ends, one end of said torsion spring being fixed against rotation in the support frame, a gear box operatively engaged with the other end of said torsion spring and having an extendible member engageable with a tracking surface of the seat portion, and an operating member easily accessible to a user sitting on the seat portion for operating said gear box to extend said extendible member thereby pre-loading the torsion spring for cushioning the user on the seat portion between said first and second positions of the seat portion.
Claim 2
Dependent Claim
126 words
A spring-tilt mechanism for a chair or seat comprising a support frame, a seat portion tiltable on the support frame about a substantially horizontal axis between a first and a second position, a torsion spring having two ends, one end of said torsion spring being fixed against rotation in the support frame, a gear box operatively engaged with the other end of said torsion spring and having an extendible member engageable with a tracking surface of the seat portion, and an operating member easily accessible to a user sitting on the seat portion for operating said gear box to extend said extendible member thereby pre-loading the torsion spring for cushioning the user on the seat portion between said first and second positions of the seat portion.
Claim 3
Dependent Claim
30 words
A spring-tilt mechanism according to claim 1, wherein said support frame comprises a substantially triangular-shaped member adjustably attached at one apex to a vertical support of a chair or seat.
Claim 4
Dependent Claim
21 words
A spring-tilt mechanism according to claim 1, wherein said tilting axis of said seat portion is adjacent a front edge thereof.
Claim 5
Dependent Claim
21 words
A spring-tilt mechanism according to claim 1, wherein said operating member is a rotatable knob or handle on said gear box.
Claim 6
Dependent Claim
27 words
A spring-tilt mechanism according to claim 4, wherein said knob or handle has an axis of rotation substantially coinciding with the longitudinal axis of said torsion spring.
Claim 7
Dependent Claim
42 words
A spring-tilt mechanism according to claim 1 wherein said extendible member comprises a threaded push-rod engaged by a threaded spindle of said gear box, said push-rod being axially movable on rotation of said threaded spindle caused by actuation of said operating member.
Claim 8
Dependent Claim
37 words
A spring-tilt mechanism according to claim 6, wherein said gear box comprises a first gearing in driving engagement with the operating member, and a second gearing drivingly connected to said first gearing and to said threaded spindle.
Claim 9
Dependent Claim
26 words
A spring-tilt mechanism according to claim 7, wherein said first and second gearings each comprise a toothed pulley, the pulleys being drivingly interconnected by toothed belting.
Claim 10
Dependent Claim
25 words
A spring-tilt mechanism according to claim 7, wherein said first gearing comprises a bevel gear engaged with a bevel gear connected to said operating member.
Claim 11
Dependent Claim
27 words
A spring-tilt mechanism according to claim 6, wherein said gear box comprises a gearing in driving engagement with the operating member and mounted on said threaded spindle.
Claim 12
Dependent Claim
20 words
A spring-tilt mechanism according to claim 1, wherein said seat portion is tiltable on said support frame via depending brackets.
Claim 13
Dependent Claim
26 words
A spring-tilt mechanism according to claim 11, wherein said depending brackets are pivotable against stops of said support frame providing said said first and second positions.
Claim 14
Dependent Claim
23 words
A spring-tilt mechanism according to claim 11, wherein said brackets are mounted on tubular means, said torsion spring passing through said tubular means.
Claim 15
Dependent Claim
24 words
A spring-tilt mechanism according to claim 13, wherein said tubular means comprises a single hollow tube, said brackets being attached to said hollow tube.
Claim 16
Dependent Claim
126 words
A chair or seat having a spring-tilt mechanism comprising a support frame, a seat portion tiltable on the support frame about a substantially horizontal axis between a first and a second position, a torsion spring having two ends, one end of said torsion spring being fixed against rotation in the support frame, a gear box operatively engaged with the other end of said torsion spring and having an extendible member engageable with a tracking surface of the seat portion, and an operating member easily accessible to a user sitting on the seat portion for operating said gear box to extend said extendible member thereby pre-loading the torsion spring for cushioning the user on the seat portion between said first and second positions of the seat portion.
Claim 17
Dependent Claim
126 words
A chair or seat having a spring-tilt mechanism comprising a support frame, a seat portion tiltable on the support frame about a substantially horizontal axis between a first and a second position, a torsion spring having two ends, one end of said torsion spring being fixed against rotation in the support frame, a gear box operatively engaged with the other end of said torsion spring and having an extendible member engageable with a tracking surface of the seat portion, and an operating member easily accessible to a user sitting on the seat portion for operating said gear box to extend said extendible member thereby pre-loading the torsion spring for cushioning the user on the seat portion between said first and second positions of the seat portion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |