Patent US4538506A successfully refreshed from Google Patents.
US4538506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cylinder with two-step movement
Assignee: Volvo AB
•
Filing: 1983-09-22
•
Granted: 1985-09-03
•
Expires: 2003-09-22
Abstract
Abstract In a cylinder with two-step movement there is in a housing (7) a first piston (6) which slides in contact with the inside of the housing. A second piston (10), which supports a piston rod (11), which moves sealingly through a first end-piece (8) also slides against the inside of the housing. In the second end-piece (9) of the housing, there is a pressure medium tube (12) passing through the first piston (6) and which extends with its end distant from the second end-piece (9) into, and is guided against the inside of the tubular piston rod (11).
Inventors
- 👤 Karl E. Mattsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:45
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/08; F15B15/14; F15B15/1409
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
191 words
In a cylinder with two-step movement, comprising a housing with a first and a second end piece, a first and a second piston sliding in contact with the inside of the housing, said second piston supporting a tube-shaped piston rod which moves sealingly through the first end piece of the housing, a pressure medium tube which is mounted in the second end piece and which passes through the first piston and extends into the tube-shaped piston rod and through which pressure medium can be led into or out of a first chamber between the first and the second pistons, and between the first end piece and the second piston a second chamber, and between the second end piece and the first piston a third chamber, the second and the third chambers each having a pressure medium connection; the improvement in which the end of the pressure medium tube extending into the piston rod has a contact portion adapted to contact the inside of the piston rod thus making the pressure medium tube serve as a guide both for the piston rod and for the second piston connected to the piston rod.
Claim 2
Dependent Claim
191 words
In a cylinder with two-step movement, comprising a housing with a first and a second end piece, a first and a second piston sliding in contact with the inside of the housing, said second piston supporting a tube-shaped piston rod which moves sealingly through the first end piece of the housing, a pressure medium tube which is mounted in the second end piece and which passes through the first piston and extends into the tube-shaped piston rod and through which pressure medium can be led into or out of a first chamber between the first and the second pistons, and between the first end piece and the second piston a second chamber, and between the second end piece and the first piston a third chamber, the second and the third chambers each having a pressure medium connection; the improvement in which the end of the pressure medium tube extending into the piston rod has a contact portion adapted to contact the inside of the piston rod thus making the pressure medium tube serve as a guide both for the piston rod and for the second piston connected to the piston rod.
Claim 3
Dependent Claim
20 words
Cylinder according to claim 1, in which said contact portion comprises a slide sleeve mounted on the pressure medium tube.
Claim 4
Dependent Claim
33 words
Cylinder according to claim 2, in which said pressure medium tube and said slide sleeve have aligned openings therethrough that communicate between the interior of the pressure medium tube and said first chamber.
Claim 5
Dependent Claim
35 words
Cylinder according to claim 2, in which the end of the pressure medium tube remote from said second end piece has a radially outwardly extending flange against which one end of said slide sleeve abuts.
Claim 6
Dependent Claim
21 words
Cylinder according to claim 1, in which the pressure medium tube is a guide for the first piston as it moves.
Claim 7
Dependent Claim
28 words
Cylinder according to claim 5, in which the pressure medium tube has a stop for the first piston to limit its movement away from the second end piece.
Claim 8
Dependent Claim
15 words
Cylinder according to claim 6, in which said stop is adjustable axially of the housing.
Claim 9
Dependent Claim
26 words
Cylinder according to claim 7, in which said stop is rigidly mounted on the pressure medium tube which is in turn adjustable axially in the cylinder.
Claim 10
Dependent Claim
44 words
Cylinder according to claim 8, in which said pressure medium tube is screw-threadedly engageable within said second end piece, whereby axial adjustment of said pressure medium tube in said cylinder is effected by rotating said pressure medium tube relative to said second end piece.
Claim 11
Dependent Claim
26 words
Cylinder according to claim 1, in which the pressure medium tube extends with its end distant from the second end piece into the first end piece.
Claim 12
Dependent Claim
29 words
Cylinder according to claim 1, in which the pressure medium tube at its end distant from the second end piece is sealed against the inside of the piston rod.
Claim 13
Dependent Claim
36 words
Cylinder according to claim 11, in which said end of said pressure medium tube distant from said second end piece carries an annular seal that slides on and seals against the inside of the piston rod.
Claim 14
Dependent Claim
17 words
Cylinder according to claim 1, which is the cylinder of a welding gun for use in welding.
References Cited (Backward Citations)
GB625711A
Cited
US2596471A
Cited
GB743603A
Cited
US3150563A
Cited
US3139004A
Cited
US3168853A
Cited
DE2247596A1
Cited
US3968735A
Cited
US4076465A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |