US3628637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extendable support column
Assignee: ZF Friedrichshafen AG
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Filing: 1970-02-17
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Granted: 1971-12-21
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Expires: 1990-02-17
Abstract
Abstract A hydropneumatic support column for a table top or the like has a cylinder, a two-part piston in the cylinder and a piston rod extending outwardly of the cylinder. Respective axial faces of the two piston parts conformingly engage axially spaced portions of the inner cylinder wall, and spacedly opposite radial walls of the piston parts bound a receptacle for an O-ring dimensioned to define a gap with the inner cylinder wall in the relaxed position. The inner end of the piston rod threadedly engages one piston part and abuttingly engages the other so that the resilient O-ring may be axially compressed between the radial walls of the piston parts by turning the external portion of the piston rod until it closes the gap, thereby breaking communication between two axial grooves in the piston parts which jointly connect the two compartments on opposite sides of the piston when the gap is open.
Inventors
- 👤 Ludwig Axthammer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:16
CPC Classifications
A; A47; A47B; A47B9/00; A47B9/10; F; F16; F16F; F16F9/00; F16F9/32; F16F9/34; F16F9/346
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
333 words
An extendable support column comprising, in combination: a. a cylinder member having an axis and an inner face of uniform cross section transversely of said axis, said face bounding a cavity in said cylinder member; b. sealing means sealing said cavity from the ambient atmosphere; c. piston means axially movable in said cavity and dividing the same into two compartments varying in their capacity during axial movement of said piston means, 1. said piston means including two piston members having respective axial faces conformingly engaging two axially spaced portions of said inner face and respective radially extending faces spacedly opposite each other and axially bounding a receptacle therebetween, the axial walls of said receptacle being constituted by said inner face and one of said piston members, 2. each piston member being formed with a conduit having an orifice in said receptacle and one of said compartments; d. a piston rod axially movable relative to said cylinder member and having a first terminal portion axially projecting from said cylinder member and a second terminal portion in said cavity threadedly engaging one of said piston members, said terminal portions being connected for joint angular movement in respective planes transverse to said axis; e. abutment means on said second terminal portion engageable with the other piston member for moving the other piston member inwardly of said receptacle toward said one piston member when said first terminal portion is turned relative to said one piston member; f. a resilient member interposed between said radially extending faces and said axial walls in said receptacle, said resilient member being dimensioned 1. to define a gap with one of said axial walls when in the relaxed condition, the gap connecting the orifices of said conduits in said receptacle, and 2. to engage said wall and thereby to close said gap when compressed between said radially extending faces during movement of said other piston member inwardly of said receptacle; and g. a fluid filling said compartments, said recesses and said gap.
Claim 2
Dependent Claim
333 words
An extendable support column comprising, in combination: a. a cylinder member having an axis and an inner face of uniform cross section transversely of said axis, said face bounding a cavity in said cylinder member; b. sealing means sealing said cavity from the ambient atmosphere; c. piston means axially movable in said cavity and dividing the same into two compartments varying in their capacity during axial movement of said piston means, 1. said piston means including two piston members having respective axial faces conformingly engaging two axially spaced portions of said inner face and respective radially extending faces spacedly opposite each other and axially bounding a receptacle therebetween, the axial walls of said receptacle being constituted by said inner face and one of said piston members, 2. each piston member being formed with a conduit having an orifice in said receptacle and one of said compartments; d. a piston rod axially movable relative to said cylinder member and having a first terminal portion axially projecting from said cylinder member and a second terminal portion in said cavity threadedly engaging one of said piston members, said terminal portions being connected for joint angular movement in respective planes transverse to said axis; e. abutment means on said second terminal portion engageable with the other piston member for moving the other piston member inwardly of said receptacle toward said one piston member when said first terminal portion is turned relative to said one piston member; f. a resilient member interposed between said radially extending faces and said axial walls in said receptacle, said resilient member being dimensioned 1. to define a gap with one of said axial walls when in the relaxed condition, the gap connecting the orifices of said conduits in said receptacle, and 2. to engage said wall and thereby to close said gap when compressed between said radially extending faces during movement of said other piston member inwardly of said receptacle; and g. a fluid filling said compartments, said recesses and said gap.
Claim 3
Dependent Claim
137 words
each piston member being formed with a conduit having an orifice in said receptacle and one of said compartments; d. a piston rod axially movable relative to said cylinder member and having a first terminal portion axially projecting from said cylinder member and a second terminal portion in said cavity threadedly engaging one of said piston members, said terminal portions being connected for joint angular movement in respective planes transverse to said axis; e. abutment means on said second terminal portion engageable with the other piston member for moving the other piston member inwardly of said receptacle toward said one piston member when said first terminal portion is turned relative to said one piston member; f. a resilient member interposed between said radially extending faces and said axial walls in said receptacle, said resilient member being dimensioned
Claim 4
Dependent Claim
137 words
each piston member being formed with a conduit having an orifice in said receptacle and one of said compartments; d. a piston rod axially movable relative to said cylinder member and having a first terminal portion axially projecting from said cylinder member and a second terminal portion in said cavity threadedly engaging one of said piston members, said terminal portions being connected for joint angular movement in respective planes transverse to said axis; e. abutment means on said second terminal portion engageable with the other piston member for moving the other piston member inwardly of said receptacle toward said one piston member when said first terminal portion is turned relative to said one piston member; f. a resilient member interposed between said radially extending faces and said axial walls in said receptacle, said resilient member being dimensioned
Claim 5
Dependent Claim
40 words
to engage said wall and thereby to close said gap when compressed between said radially extending faces during movement of said other piston member inwardly of said receptacle; and g. a fluid filling said compartments, said recesses and said gap.
Claim 6
Dependent Claim
40 words
to engage said wall and thereby to close said gap when compressed between said radially extending faces during movement of said other piston member inwardly of said receptacle; and g. a fluid filling said compartments, said recesses and said gap.
Claim 7
Dependent Claim
31 words
A column as set forth in claim 1, wherein said one piston member has a radially reduced portion, said other piston member being annular and slidably receiving said reduced portion therein.
Claim 8
Dependent Claim
42 words
A column as set forth in claim 1, wherein said axial faces of said piston members are formed with respective grooves open toward said inner face, said grooves constituting said conduits, said one axial wall of said receptacle being said inner face.
Claim 9
Dependent Claim
20 words
A column as set forth in claim 1, wherein said receptacle and said resilient member are annular about said axis.
Claim 10
Dependent Claim
20 words
A column as set forth in claim 4, wherein said resilient member is substantially tore-shaped when in said relaxed condition.
Claim 11
Dependent Claim
38 words
A column as set forth in claim 1, wherein the overall axial length of said piston means, as measured over said axial faces of said piston members, is at least equal to the radius of said inner face.
Claim 12
Dependent Claim
36 words
A column as set forth in claim 6, wherein the axial length of one of said axial faces is approximately equal to and not substantially smaller than one-half of said axial length of said piston means.
Claim 13
Dependent Claim
22 words
A column as set forth in claim 7, wherein said one axial face is said axial face of said one piston member.
Claim 14
Dependent Claim
43 words
A column as set forth in claim 8, wherein said one piston member has a radially reduced portion axially offset from said axial face thereof, said other piston member being annular and having a bore slidably receiving said reduced portion in conforming engagement.
References Cited (Backward Citations)
US3376957A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |