US5020418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piston lock for power cylinders
Assignee: Individual
•
Filing: 1989-08-02
•
Granted: 1991-06-04
•
Expires: 2009-08-02
Abstract
Abstract A power cylinder of the type in which the piston may be locked to maintain the associated tool or clamp in a fixed position. A pair of guide rods extend in parallel spaced fashion through the bore of the cylinder from end to end of the cylinder and the piston includes a pair of spaced apertures passing the guide rods so that the piston may slide within the bore of the cylinder on the guide rods. The piston apertures are internally threaded and the guide rods include an externally threaded portion so that, following movement of the piston within the bore through a rapid advance portion of its stroke under the influence of pressure fluid, the internal threads in the piston apertures are brought into engagement with the externally threaded portions of the guide rods and the guide rods are thereafter rotated so as to threadably advance the piston to its final desired position in which the piston is lockingly held by the coacting threads. Rotation of the guide rods is achieved in one embodiment by a rack and pinion arrangement and is achieved in another embodiment by an air motor.
Inventors
- 👤 Jack J. Sendoykas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:00
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/20; F15B15/26; F15B15/262; F15B15/264; F15B15/08; F15B15/14; F15B2015/1495
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
76 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for movement in said bore along said guide rod through a stroke; fluid pressure means operative to move said piston along said guide rod through a first portion of said stroke; and thread means operative to move said piston along said guide rod through a second portion of said stroke.
Claim 2
Dependent Claim
76 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for movement in said bore along said guide rod through a stroke; fluid pressure means operative to move said piston along said guide rod through a first portion of said stroke; and thread means operative to move said piston along said guide rod through a second portion of said stroke.
Claim 3
Dependent Claim
49 words
A power cylinder according to claim 1 wherein: said thread means includes thread means on said piston and thread means on said guide rod coacting with said piston thread means in response to rotation of said guide rod to move said piston through said second portion of said stroke.
Claim 4
Dependent Claim
29 words
A power cylinder according to claim 2 wherein: said piston thread means comprises internal threads in an aperture in said piston coating with external threads on said guide rod.
Claim 5
Dependent Claim
202 words
A power cylinder comprising: a cylinder housing defining a front end wall, a rear end wall, and a cylindrical bore extending axially between said end walls; a pair of guide rods extending axially through said bore between said end walls in parallel, spaced relation; a piston positioned in said bore and including a pair of spaced apertures respectively passing said guide rods; a piston rod rigid with said piston and extending through said front end wall; means for delivering pressure fluid to said bore so as to move said piston axially in said bore along said guide rods; means for rotating said guide rods; means operative in response to rotation of said guide rods to advance said piston axially in said bore independently of the action of the pressure fluid; each of said guide rods including a smooth unthreaded portion an da threaded portion; each of said apertures including a guide portion slidably receiving the unthreaded portion of a respective guide rod and a threaded portion for coaction with the threaded portion of a respective guide rods; and said advancing means being provided by the threaded coaction of said threaded portions of said apertures with said threaded portions of said guide rods.
Claim 6
Dependent Claim
202 words
A power cylinder comprising: a cylinder housing defining a front end wall, a rear end wall, and a cylindrical bore extending axially between said end walls; a pair of guide rods extending axially through said bore between said end walls in parallel, spaced relation; a piston positioned in said bore and including a pair of spaced apertures respectively passing said guide rods; a piston rod rigid with said piston and extending through said front end wall; means for delivering pressure fluid to said bore so as to move said piston axially in said bore along said guide rods; means for rotating said guide rods; means operative in response to rotation of said guide rods to advance said piston axially in said bore independently of the action of the pressure fluid; each of said guide rods including a smooth unthreaded portion an da threaded portion; each of said apertures including a guide portion slidably receiving the unthreaded portion of a respective guide rod and a threaded portion for coaction with the threaded portion of a respective guide rods; and said advancing means being provided by the threaded coaction of said threaded portions of said apertures with said threaded portions of said guide rods.
Claim 7
Dependent Claim
31 words
A power cylinder according to claim 4 wherein: said rotating means comprises means defining a spur gear on each guide rod and a central drive gear meshingly engaging said spur gear.
Claim 8
Dependent Claim
64 words
A power cylinder according to claim 5 wherein: said threaded portions of said guide rods are provided proximate said front end wall; said piston is mounted on said guide rods with said threaded portions of said apertures between said guide portions of said apertures and said front end wall; and said spur gears are provided on said guide rods proximate said rear end wall.
Claim 9
Dependent Claim
87 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for reciprocal movement in said bore along said guide rod; means operative in response to rotation of said guide rod to advance said piston axially in said bore; and means operative in response to delivery of pressure fluid to said bore to move said piston axially in said bore along said guide rod independently of the operation of said advancing means.
Claim 10
Dependent Claim
87 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for reciprocal movement in said bore along said guide rod; means operative in response to rotation of said guide rod to advance said piston axially in said bore; and means operative in response to delivery of pressure fluid to said bore to move said piston axially in said bore along said guide rod independently of the operation of said advancing means.
Claim 11
Dependent Claim
22 words
A power cylinder according to claim 7 wherein: said advancing means comprises coacting threads on said piston and on said guide rod.
Claim 12
Dependent Claim
137 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for reciprocal movement in said bore along said guide rod; means for delivering pressure fluid to said bore to move said piston axially in said bore along said guide rod; means operative in response to rotation of said guide rod to advance said piston axially in said bore independently of the action of the pressure fluid; said guide rod including an unthreaded portion and a threaded portion; said piston including an internally threaded aperture passing said unthreaded guide rod portion and threadably coating with said threaded guide rod portion; and said advancing means comprising the threads in said piston aperture in coaction with the threads on said threaded guide rod portion.
Claim 13
Dependent Claim
137 words
A power cylinder comprising: a cylinder housing defining an axial bore; a guide rod extending axially in said bore; a piston mounted on said guide rod for reciprocal movement in said bore along said guide rod; means for delivering pressure fluid to said bore to move said piston axially in said bore along said guide rod; means operative in response to rotation of said guide rod to advance said piston axially in said bore independently of the action of the pressure fluid; said guide rod including an unthreaded portion and a threaded portion; said piston including an internally threaded aperture passing said unthreaded guide rod portion and threadably coating with said threaded guide rod portion; and said advancing means comprising the threads in said piston aperture in coaction with the threads on said threaded guide rod portion.
Claim 14
Dependent Claim
77 words
A power cylinder according to claim 9 wherein: said guide rod comprises a first guide rod; said cylinder further includes a second guide rod extending axially in said bore in parallel spaced relation to said first guide rod and including an unthreaded portion and a threaded portion; and said piston includes another internally threaded aperture slidably passing said unthreaded portion of said second guide rod and threadably coacting with said threaded portion of said second guide rod.
Claim 15
Dependent Claim
43 words
A power cylinder according to claim 10 wherein: each of said guide rods includes means defining a driven gear; and said rotating means comprises a drive gear meshingly engaging said driven gears on said guide rods and means for rotating said drive gear.
Claim 16
Dependent Claim
29 words
A power cylinder according to claim 11 wherein: said means for rotating said drive gear comprises an air motor having an output shaft drivingly coupled to said drive gear.
Claim 17
Dependent Claim
55 words
A power cylinder according to claim 11 wherein: said means for rotating said drive gear comprises a rack engaging the periphery of said drive gear and operative in response to linear movement of said rack to rotate said drive gear and thereby rotate said driven gears to rotate said guide rods and advance said piston.
Claim 18
Dependent Claim
47 words
A power cylinder according to claim 9 wherein: said internally threaded aperture is defined in a drive portion of said piston; and said piston further includes a guide portion defining a smooth walled aperture coaxial with said threaded aperture and slidably receiving said unthreaded guide rod portion.
Claim 19
Dependent Claim
46 words
A power cylinder according to claim 14 wherein: said piston is mounted on said guide rod with said piston guide portion slidably mounted on said guide rod unthreaded portion and said piston drive portion positioned between said piston guide portion and said guide rod threaded portion.
Claim 20
Dependent Claim
38 words
A power cylinder according to claim 15 wherein: said guide rod threaded portion is proximate one end of said guide rod; and said rotating means includes a spur gear defined proximate the other end of said guide rod.
Claim 21
Dependent Claim
133 words
A power cylinder comprising: a cylinder housing defining a front end wall, a rear end wall, and a cylindrical bore extending axially between said end walls; a pair of guide rods extending axially through said bore between said end walls in parallel, spaced relation; a piston positioned in said bore and including a pair of spaced apertures respectively passing said guide rods; a piston rod rigid with said piston and extending through said front end wall; means for rotating said guide rods; means operative in response to rotation of said guide rods to advance said piston axially in said bore; and means operative in response to delivery of pressure fluid to said bore to move said piston axially in said bore along said guide rods independently of the operation of said advancing means.
Claim 22
Dependent Claim
133 words
A power cylinder comprising: a cylinder housing defining a front end wall, a rear end wall, and a cylindrical bore extending axially between said end walls; a pair of guide rods extending axially through said bore between said end walls in parallel, spaced relation; a piston positioned in said bore and including a pair of spaced apertures respectively passing said guide rods; a piston rod rigid with said piston and extending through said front end wall; means for rotating said guide rods; means operative in response to rotation of said guide rods to advance said piston axially in said bore; and means operative in response to delivery of pressure fluid to said bore to move said piston axially in said bore along said guide rods independently of the operation of said advancing means.
Claim 23
Dependent Claim
121 words
A power cylinder comprising: a cylinder housing defining an axial bore; a piston mounted in said bore for movement through a stroke and including an aperture having internal threads; a rod mounted for rotation in said bore about an axis parallel to the central axis of said bore, passing through said piston aperture, and including external threads for threaded coaction with said piston threads; fluid pressure means for moving said piston in said bore through a portion of its stroke; said rod including a smooth unthreaded portion and a threaded portion defining said external threads; and said piston aperture including a smooth unthreaded portion slidably guiding on said unthreaded portion of said rod and a threaded portion defining said internal threads.
Claim 24
Dependent Claim
121 words
A power cylinder comprising: a cylinder housing defining an axial bore; a piston mounted in said bore for movement through a stroke and including an aperture having internal threads; a rod mounted for rotation in said bore about an axis parallel to the central axis of said bore, passing through said piston aperture, and including external threads for threaded coaction with said piston threads; fluid pressure means for moving said piston in said bore through a portion of its stroke; said rod including a smooth unthreaded portion and a threaded portion defining said external threads; and said piston aperture including a smooth unthreaded portion slidably guiding on said unthreaded portion of said rod and a threaded portion defining said internal threads.
References Cited (Backward Citations)
US2886008A
Cited
US2773485A
Cited
US2815005A
Cited
US2918786A
Cited
US2970573A
Cited
US3236489A
Cited
US3576151A
Cited
US3668977A
Cited
US3702535A
Cited
US3732783A
Cited
US3763747A
Cited
JPS5224680A
Cited
US4196654A
Cited
US4462768A
Cited
US4790234A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |