US3568592A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power hammer
Assignee: Vyzkumny Ustav Tvarecich Stroju a Technologie Tvareni
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Filing: 1969-03-17
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Granted: 1971-03-09
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Expires: 1989-03-17
Abstract
Abstract In a power hammer wherein work located on an anvil is acted upon by a ram located over the anvil an upper piston-and-cylinder means coacts with the ram to lower the latter along a driving stroke by way of a gaseous fluid under pressure and to raise the ram back to its starting position along its return stroke by way of a hydraulic fluid under pressure. A frame means which carries the anvil also carries part of this upper piston-and-cylinder means, while another part thereof is operatively connected with the ram. Beneath the frame means the foundation carries part of a lower piston-and-cylinder means which is operatively connected with the frame means for raising and lowering the latter. A conduit provides communication between the hydraulic fluid of the upper piston-and-cylinder means and the lower piston-and-cylinder means. A control valve is provided in the conduit to open the latter so that when the gas drives the ram downwardly the hydraulic fluid under pressure will flow through the conduit from the upper piston-and-cylinder means into the lower piston-andcylinder means to raise the frame means, and the anvil therewith, simultaneously with the downward movement of the ram.
Inventors
- 👤 Pavel Harvanek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:00
CPC Classifications
B; B21; B21J; B21J7/00; B21J7/20; B21J7/22; B21J7/34
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
In a power hammer, a ram and an anvil situated therebeneath, movable frame means carrying said anvil for movement jointly therewith, upper piston-and-cylinder means carried in part by said frame means and operatively connected in part to said ram for driving the latter along a downward working stroke with a gaseous pressure fluid and for raising said ram along its return stroke with a hydraulic pressure fluid, lower piston-and-cylinder means carried by a foundation beneath said frame means and operatively connected with said frame means for raising and lowering the latter, operating conduit means providing communication between said lower piston-and-cylinder means and the hydraulic fluid of said upper piston-and-cylinder means, and control valve means operatively connected with said conduit means for opening the latter to provide for flow of the hydraulic fluid from said upper to said lower piston-and-cylinder means for raising said frame means and anvil while said ram is driven downwardly by said upper piston-and-cylinder means.
Claim 2
Dependent Claim
158 words
In a power hammer, a ram and an anvil situated therebeneath, movable frame means carrying said anvil for movement jointly therewith, upper piston-and-cylinder means carried in part by said frame means and operatively connected in part to said ram for driving the latter along a downward working stroke with a gaseous pressure fluid and for raising said ram along its return stroke with a hydraulic pressure fluid, lower piston-and-cylinder means carried by a foundation beneath said frame means and operatively connected with said frame means for raising and lowering the latter, operating conduit means providing communication between said lower piston-and-cylinder means and the hydraulic fluid of said upper piston-and-cylinder means, and control valve means operatively connected with said conduit means for opening the latter to provide for flow of the hydraulic fluid from said upper to said lower piston-and-cylinder means for raising said frame means and anvil while said ram is driven downwardly by said upper piston-and-cylinder means.
Claim 3
Dependent Claim
68 words
The combination of claim 1 and wherein a bypass valve means communicates with said operating conduit means bypassing said control valve means for directing hydraulic pressure fluid from said lower back to said upper piston-and-cylinder means for at least partially returning said ram upwardly to its starting position directly after impact on the work by the downwardly moving ram and anvil carried by the upwardly moving frame means.
Claim 4
Dependent Claim
79 words
The combination of claim 1 and wherein said upper piston-and-cylinder means includes a cylinder carried by said frame means and a piston operatively connected to said ram and movable in said cylinder, said cylinder having a space beneath said piston in which is located the hydraulic fluid under pressure which communicates through said operating conduit means with said lower piston-and-cylinder means, and the space within said cylinder above said piston being adapted to accommodate a gaseous fluid under pressure.
Claim 5
Dependent Claim
121 words
The combination of claim 1 and wherein a supply conduit means communicates with said operating conduit means at a location between said control valve means and said upper piston-and-cylinder means for supplying hydraulic fluid under pressure to the latter, pump means communicating with said supply conduit means for pumping hydraulic fluid under pressure thereto, suction conduit means leading into said pump means for delivering hydraulic fluid thereto, and connecting conduit means leading from said lower piston-and-cylinder means to said suction conduit means so that during downward movement of said frame means part of the hydraulic fluid displaced out of said lower piston-and-cylinder means will flow into and through said pump means along said supply conduit means to said upper piston-and-cylinder means.
Claim 6
Dependent Claim
34 words
The combination of claim 1 and wherein said lower piston-and-cylinder means includes stationary cylinders carried by the foundation and pistons respectively fixed to said frame means and extending therefrom downwardly into the latter cylinders.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |