US3952987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chair adjustment construction
Assignee: BEVCO PRECISION Manufacturing Co
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Filing: 1974-10-24
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Granted: 1976-04-27
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Expires: 1994-10-24
Abstract
Abstract A chair construction of the type including a base with an upstanding supporting tube and a seat with a depending tube telescopically fitted within the upstanding tube, includes an improved height adjustment mechanism for the seat. A manually operated handle or trigger on the upstanding tube has an inclined planar tab that fits into any one of a plurality of slots defined in the depending tube to provide desired seat elevation. The tubes have a hexagonal cross section with complementary wedge surfaces so that the depending tube is guided by the planar tab into wedging engagement with the upstanding tube.
Inventors
- 👤 Kenneth A. Bevington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:54
CPC Classifications
A; A47; A47C; A47C3/00; A47C3/20; A47C3/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
175 words
In a chair construction of the type including a base having an upstanding supporting tube, and a seat with a depending guide tube connected at its upper end to said seat, said depending tube being telescopically fitted within said upstanding tube, the improvement comprising an elevation adjustment mechanism for the telescoped tubes; said mechanism including a plurality of verically spaced openings, each opening defining a substantially horizontal planar bearing surface in said depending tube; a lever arm attached to one side of said upstanding tube, said lever arm including a downwardly inclined member having a planar surface for engaging the bearing surface through a chosen one of said openings; means for normally biasing said lever member downwardly into said one opening; and said tubes including at least a pair of engaging, complementary, wedge surfaces generally opposite said lever arm, whereby the depending tube wedge surface is directed by said inclined member into frictional wedge locking engagement with the upstanding member wedge surface while simultaneously retaining said opening in alignment for engagement by said lever arm.
Claim 2
Dependent Claim
175 words
In a chair construction of the type including a base having an upstanding supporting tube, and a seat with a depending guide tube connected at its upper end to said seat, said depending tube being telescopically fitted within said upstanding tube, the improvement comprising an elevation adjustment mechanism for the telescoped tubes; said mechanism including a plurality of verically spaced openings, each opening defining a substantially horizontal planar bearing surface in said depending tube; a lever arm attached to one side of said upstanding tube, said lever arm including a downwardly inclined member having a planar surface for engaging the bearing surface through a chosen one of said openings; means for normally biasing said lever member downwardly into said one opening; and said tubes including at least a pair of engaging, complementary, wedge surfaces generally opposite said lever arm, whereby the depending tube wedge surface is directed by said inclined member into frictional wedge locking engagement with the upstanding member wedge surface while simultaneously retaining said opening in alignment for engagement by said lever arm.
Claim 3
Dependent Claim
39 words
The improved chair construction of claim 1 wherein said lever arm includes a handle connected to the downwardly depending member, said handle being manually engageable to transport said downwardly depending member into and out of engagement with said openings.
Claim 4
Dependent Claim
34 words
The improved chair construction of claim 1 wherein said openings comprise slots transverse to the longitudinal axis of said tubes and wherein said downwardly inclined member comprises a planar tab for engaging said slots.
Claim 5
Dependent Claim
38 words
The improved chair construction of claim 1 wherein said tubes have the same cross sectional shape and each tube includes at least two surfaces parallel to the longitudinal axis thereof joined together to define an included acute angle.
Claim 6
Dependent Claim
15 words
The improved chair construction of claim 4 wherein said tubes have a hexagonal cross section.
Claim 7
Dependent Claim
15 words
The improved chair construction of claim 4 wherein said angle includes said downwardly inclined member.
Claim 8
Dependent Claim
42 words
The improved chair construction of claim 1 wherein said downwardly inclined member has a locking position and a release position, said member engaging the top edge of said tube and simultaneously engaging the top of one opening when in the locking position.
Claim 9
Dependent Claim
23 words
The improved chair construction of claim 1 including stop means on said lever arm to limit the biased travel of said lever arm.
Claim 10
Dependent Claim
24 words
The improved chair construction of claim 1 wherein said lever arm projects over the top edge of the upstanding tube and into said tube.
References Cited (Backward Citations)
US1007322A
Cited
US1725312A
Cited
US2019753A
Cited
GB451122A
Cited
US2122868A
Cited
GB565820A
Cited
US2382291A
Cited
US2542480A
Cited
DE902779C
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |