Patent US3889586A successfully refreshed from Google Patents.
US3889586A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control for fluid pressure actuators
Assignee: USM Corp
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Filing: 1973-08-21
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Granted: 1975-06-17
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Expires: 1993-08-21
Abstract
Abstract A control for hydraulic actuators preferably relatively moving platens of a press toward each other has means for coordinating the operation of the actuators. Preferably, the coordinating means comprise valves throttling fluid supply to each actuator and means for coordinating the operation of the valves. The control preferably also has a device for adjusting a preset function of the actuators, a device responsive to fluid pressure in the actuators for relieving excess pressure to the actuators and a device for preventing operation of the actuators during preparation for press operation.
Inventors
- 👤 Frederick A Pretty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:16
CPC Classifications
B; B30; B30B; B30B15/00; B30B15/16; B21; B21D; B21D28/00; B21D28/002
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
249 words
In a press having a movable platen which is driven by fluid piston and cylinder means against a relatively fixed platen, a system for supplying and controlling fluid under pressure to the piston and cylinder means comprising: A. a first pump connected to supply pressurized fluid to the piston and cylinder means at low pressure and high volume; B. a second pump connected to supply pressurized fluid to the piston and cylinder means at high pressure and low volume; C. a conduit connected to receive the pressurized fluid frOm both pumps and for directing said fluid to the piston and cylinder means; D. first valve means connected to the first pump and the conduit to divert fluid from said pump away from said conduit when the pressure in the conduit reaches a predetermined value, thereby allowing further movement of the movable platen to be caused solely by the pressurized fluid from the second pump; E. mechanically actuated second valve means associated with the piston and cylinder means to control the flow of pressurized fluid from the conduit to the piston and cylinder means; F. a mechanical assembly operatively associated with a lead screw for actuating the second valve means, said lead screw being driven by a first fluid motor; and G. third valve means connected to the first pump to cause said first pump to supply low pressure, high volume fluid to the first fluid motor in order to drive said lead screw, thereby actuating the second valve means.
Claim 2
Dependent Claim
249 words
In a press having a movable platen which is driven by fluid piston and cylinder means against a relatively fixed platen, a system for supplying and controlling fluid under pressure to the piston and cylinder means comprising: A. a first pump connected to supply pressurized fluid to the piston and cylinder means at low pressure and high volume; B. a second pump connected to supply pressurized fluid to the piston and cylinder means at high pressure and low volume; C. a conduit connected to receive the pressurized fluid frOm both pumps and for directing said fluid to the piston and cylinder means; D. first valve means connected to the first pump and the conduit to divert fluid from said pump away from said conduit when the pressure in the conduit reaches a predetermined value, thereby allowing further movement of the movable platen to be caused solely by the pressurized fluid from the second pump; E. mechanically actuated second valve means associated with the piston and cylinder means to control the flow of pressurized fluid from the conduit to the piston and cylinder means; F. a mechanical assembly operatively associated with a lead screw for actuating the second valve means, said lead screw being driven by a first fluid motor; and G. third valve means connected to the first pump to cause said first pump to supply low pressure, high volume fluid to the first fluid motor in order to drive said lead screw, thereby actuating the second valve means.
Claim 3
Dependent Claim
123 words
In a press having a movable platen which is driven by fluid piston and cylinder means against a relatively fixed platen, a system for supplying and controlling fluid under pressure to the piston and cylinder means as described in claim 1 wherein the relatively fixed platen may be moved to and from an out-of-the-way position and said movement is caused by a system comprising: A. a second fluid motor operatively connected to the relatively fixed platen to move said platen into and out of its operative position; and B. fourth valve means connected to the second pump to cause said pump to supply high pressure low volume fluid to the second fluid motor in order to actuate movement of the relatively fixed platen.
Claim 4
Dependent Claim
106 words
In a press having a movable platen which is driven by fluid piston and cylinder means against a relatively fixed platen, a system for supplying and controlling fluid under pressure to the piston and cylinder means as described in claim 2, further comprising a switch actuated by movement of the relatively fixed platen into its operative position, said switch being connected to the fourth valve means to cause said valve to direct fluid from the second pump away from the second fluid motor to the conduit; and to the third valve means to cause said first pump to supply pressurized fluid to the first fluid motor.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |