Patent US4096727A successfully refreshed from Google Patents.
US4096727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Punching, stamping and rivetting apparatus
Assignee: Individual
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Filing: 1976-04-29
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Granted: 1978-06-27
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Expires: 1996-04-29
Abstract
Abstract A hydraulic punch press having a base adapted to receive a workpiece and a cylinder axially disposed opposite to the base. The cylinder includes a first and second piston slidable defining within its interior, a first chamber formed between the surface of said first piston and one end of said cylinder and a second chamber formed between the first and second pistons. The pistons have coaxial rods extending outwardly of the other end of the cylinder in opposition to said base. The rod of the first piston extends axially through the rod of said second piston and carries at its end a tool while the rod of the second piston is tubular and is adapted to carry at its end holding means for the workpiece blank. Conduit means lead to each of the first and second chambers, from means for alternately delivering, simultaneously to said first and second chamber, hydraulic fluid of high pressure and lower pressure, respectively, to thereby reciprocate the rods of both pistons outwardly in a work phase, and the rod of the first piston inwardly in a retraction phase while maintaining the rod of said second piston in holding engagement with the workpiece blank and the workpiece holder is released and retracted when the second chamber is freed of hydraulic pressure fluid.
Inventors
- 👤 Daniel Pierre Gargaillo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:11
CPC Classifications
B; B21; B21J; B21J15/00; B21J15/10; B21D; B21D28/00; B21D28/002; B21D28/24; Y; Y10; Y10T; Y10T83/00; Y10T83/566; Y10T83/5669; Y10T83/5787; Y10T83/5805; Y10T83/869; Y10T83/8821; Y10T83/8858
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
213 words
A hydraulic punch press comprising a base adapted to receive a workpiece, a cylinder axially disposed opposite to said base, first and second pistons slidably mounted within said cylinder and defining therewithin a first chamber formed between the upper surface of said first piston and one end of said cylinder and a second chamber formed between the first and second pistons, said pistons having coaxial rods extending outwardly of the other end of said cylinder in opposition to said base, the rod of the first piston extending axially through the rod of said second piston and being adapted to carry at its free end a tool, the rod of said second piston being tubular and being adapted to carry at its end holding means for the workpiece, conduit means leading to each of said first and second chambers, and means for alternately delivering simultaneously to said first and second chambers hydraulic fluid of high pressure and lower pressure respectively to thereby sequentially reciprocate the rods of both said pistons outwardly in a work phase in which said workpiece holding means engages the workpiece prior to the tool and said rod of said first piston inwardly in a retraction phase while maintaining the rod of said second piston in holding engagement with said workpiece.
Claim 2
Dependent Claim
213 words
A hydraulic punch press comprising a base adapted to receive a workpiece, a cylinder axially disposed opposite to said base, first and second pistons slidably mounted within said cylinder and defining therewithin a first chamber formed between the upper surface of said first piston and one end of said cylinder and a second chamber formed between the first and second pistons, said pistons having coaxial rods extending outwardly of the other end of said cylinder in opposition to said base, the rod of the first piston extending axially through the rod of said second piston and being adapted to carry at its free end a tool, the rod of said second piston being tubular and being adapted to carry at its end holding means for the workpiece, conduit means leading to each of said first and second chambers, and means for alternately delivering simultaneously to said first and second chambers hydraulic fluid of high pressure and lower pressure respectively to thereby sequentially reciprocate the rods of both said pistons outwardly in a work phase in which said workpiece holding means engages the workpiece prior to the tool and said rod of said first piston inwardly in a retraction phase while maintaining the rod of said second piston in holding engagement with said workpiece.
Claim 3
Dependent Claim
44 words
The press according to claim 1 including a compression spring interposed between said second piston and the end of said cylinder for resiliently biasing said second piston towards the interior of said cylinder, and means for relieving the hydraulic fluid in said second chamber.
Claim 4
Dependent Claim
146 words
The press according to claim 1 wherein said means for delivering said hydraulic fluid comprises a slide valve connected to a source of fluid under high pressure, a source of fluid under a constant pressure lower than said high pressure, and a discharge tank, said slide valve having three positions, (a) a first work position in which the first chamber is connected to the source of high fluid pressure and the second chamber is connected to the source of constant lower fluid pressure; (b) a second retraction of position in which the first chamber is connected to the source of constant lower fluid pressure and the second chamber is connected to the source of high fluid pressure; (c) a third inoperative position in which the first chamber is connected to the tank and the second chamber is connected to the source of constant lower fluid pressure.
Claim 5
Dependent Claim
24 words
The press according to claim 3 wherein said high pressure fluid source is a pump and said lower pressure fluid source is an accumulator.
Claim 6
Dependent Claim
27 words
The press according to claim 3 including pressure limiting valves interposed between said slide valves and said high pressure fluid source and said low pressure fluid source.
Claim 7
Dependent Claim
22 words
The press according to claim 1 wherein the workpiece holder and the base have complementary formed means to cooperatively hold the workpiece.
Claim 8
Dependent Claim
14 words
The press according to claim 6 including means to prevent rotation of said tool.
Claim 9
Dependent Claim
47 words
The press according to claim 1, in which the holder piston has an extended piston-rod emerging from the cylinder, on which, by a mechanical means external of the cylinder, a force at least partially constituting the force actuating the tool in its work stroke can be applied.
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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) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |