US3815480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable stroke cylinder
Assignee: Individual
•
Filing: 1969-11-17
•
Granted: 1974-06-11
•
Expires: 1989-11-17
Abstract
Abstract In a variable stroke cylinder having a pair of pistons in which the distance between the pistons is selectively variable for selectively varying the stroke of the cylinder, a vent communicates with the space between the pistons for venting the space when the distance between the pistons is being varied.
Inventors
- 👤 R Spyra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:33
CPC Classifications
F; F03; F03C; F03C1/00; F01; F01B; F01B17/00; F01B17/02; F15; F15B; F15B15/00; F15B15/20; F15B15/24
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
In a variable stroke cylinder, a cylinder member, a pair of piston members spaced a predetermined distance from each other so as to define a space therebetween, said piston members being mounted for simultaneous axial movement in said cylinder member during normal operation thereof, means for selectively moving at least one of said piston members relative to the other said piston member for adjustably varying the stroke of said piston members by moving said piston members relative to each other to vary said predetermined distance between said members, the improvement which enables rapid and extensive stroke adjustment therein and which comprises in combination therewith: vent means communicating with said space between said piston members for venting said space when said predetermined distance between the piston members is varied to vary the stroke of the cylinder to maintain the pressure in said space substantially constant during said stroke adjustment, wherein said vent means comprises a bleed orifice in one of said piston members communicating between the face of said piston member adjacent said space and the opposite face of said piston member.
Claim 2
Dependent Claim
181 words
In a variable stroke cylinder, a cylinder member, a pair of piston members spaced a predetermined distance from each other so as to define a space therebetween, said piston members being mounted for simultaneous axial movement in said cylinder member during normal operation thereof, means for selectively moving at least one of said piston members relative to the other said piston member for adjustably varying the stroke of said piston members by moving said piston members relative to each other to vary said predetermined distance between said members, the improvement which enables rapid and extensive stroke adjustment therein and which comprises in combination therewith: vent means communicating with said space between said piston members for venting said space when said predetermined distance between the piston members is varied to vary the stroke of the cylinder to maintain the pressure in said space substantially constant during said stroke adjustment, wherein said vent means comprises a bleed orifice in one of said piston members communicating between the face of said piston member adjacent said space and the opposite face of said piston member.
Claim 3
Dependent Claim
16 words
The cylinder of claim 1 wherein said bleed orifice is in said selectively moveable piston member.
Claim 4
Dependent Claim
46 words
The cylinder of claim 1 wherein said piston members include an elongated rod, the rod of one of said piston members being threadedly journaled through the other of said rods, whereby rotation of one of said rod effects said selective relative movement of said piston members.
Claim 5
Dependent Claim
28 words
The cylinder of claim 3 further including locking means, comprising threaded plug means positioned in the second mentioned rod and movable into contact with the first mentioned rod.
Claim 6
Dependent Claim
49 words
The cylinder of claim 3 wherein said piston members and said cylinder member are non-circular in cross section for preventing rotation of said piston members, and at least one of said rods is rotatable relative to its piston member to effect said selective relative movement of said piston members.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |