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US3923280A Expired / Lapsed US ⏱️ 0.0 years remaining

Adjustable support column for a pivotal chair

Assignee: Harter Corp
•
Filing: 1975-03-21
•
Granted: 1975-12-02
•
Expires: 1995-03-21
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Abstract

Abstract An adjustable support column for pivotally mounting the seat section of a chair to the base portion thereof. The nave of the base portion has an upwardly flared bore into which the lower, tapered end portion of a sheath tube is supportingly received. A thrust bearing is mounted inside the lower end portion of the sheath tube and rotatably supports an adjusting screw. The seat section has a conical spindle that is received within a conical socket at the upper end of the spindle tube. A bushing is fixed to the lower end portion of the spindle tube and is threaded onto the adjusting screw. The bearing and bushing are selected such that the bearing offers less resistance to relative rotation between the adjusting screw and the sheath tube than the bushing offers to relative rotation between the adjusting screw and the spindle tube. A knob means is attached to the adjusting screw exteriorily of the support column in order to afford a means by which to overcome the aforesaid resistance to relative rotation offered by the bushing in order to permit selective adjustment in the height of the seat section with respect to the base portion of the seat.

Inventors

  • 👤 Wayne W Good

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 14:55
CPC Classifications
A; A47; A47C; A47C3/00; A47C3/20; A47C3/24

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 119 words
An adjustable support column for pivotally mounting the seat section of a chair to a base portion comprising: a sheath tube extending upwardly from the base portion; bearing means carried by said sheath tube; an adjusting screw supported by said bearing means for rotation relative to said sheath tube; knob means to control rotation of said adjusting screw; a spindle tube supporting the seat section extending downwardly therefrom; a bushing fastened to said spindle tube and threaded onto said adjusting screw to rotate with and with respect thereto; and, means to assure that the resistance to relative rotation between said bushing and said adjusting screw exceeds the resistance to relative rotation between said adjusting screw and said sheath tube.
Claim 2
Dependent Claim 119 words
An adjustable support column for pivotally mounting the seat section of a chair to a base portion comprising: a sheath tube extending upwardly from the base portion; bearing means carried by said sheath tube; an adjusting screw supported by said bearing means for rotation relative to said sheath tube; knob means to control rotation of said adjusting screw; a spindle tube supporting the seat section extending downwardly therefrom; a bushing fastened to said spindle tube and threaded onto said adjusting screw to rotate with and with respect thereto; and, means to assure that the resistance to relative rotation between said bushing and said adjusting screw exceeds the resistance to relative rotation between said adjusting screw and said sheath tube.
Claim 3
Dependent Claim 39 words
An adjustable support column, as set forth in claim 1, in which said spindle tube is insertable axially within said sheath tube and means are provided slidably to support said spindle tube concentriCally with respect to said sheath tube.
Claim 4
Dependent Claim 47 words
An adjustable support column, as set forth in claim 2, in which the lower end portion of said sheath tube is directed radially inwardly to present an annular cup and supporting flange, said bearing means being removably positioned within said cup and carried on said supporting flange.
Claim 5
Dependent Claim 53 words
An adjustable support column, as set forth in claim 3, in which said knob means is demountably secured to said adjusting screw and the diameter of said bearing means is of lesser dimension than the internal diameter of the means slidably to support said spindle tube concentrically with respect to said sheath tube.
Claim 6
Dependent Claim 55 words
An adjustable support column, as set forth in claim 1, in which said base portion comprises a plurality of leg members extending radially outwardly from a nave, a conically upwardly flared bore presented from said nave, the lower end portion of said sheath tube being conically tapered to be supportingly received within said flared bore.
Claim 7
Dependent Claim 49 words
An adjustable support column, as set forth in claim 1, in which a conically tapered spindle is secured to and extends downwardly from said seat section, a conically flared socket is presented from the upper end portion of said spindle tube, said spindle being supportingly received within said socket.

References Cited (Backward Citations)

US526045A Cited
US682844A Cited
US1242110A Cited
US2219814A Cited
US3799486A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-12-01 1979-06-02 1979-12-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-12-01 1983-06-02 1983-12-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-12-01 1987-06-02 1987-12-02 $7700.00 Window Closed / Lapsed

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