US3625637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conversion of variable delivery pump to fixed delivery pump
Assignee: Caterpillar Inc
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Filing: 1970-04-13
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Granted: 1971-12-07
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Expires: 1990-04-13
Abstract
Abstract A variable delivery fluid pump and a variable delivery fluid motor are used to accelerate the spindle of an inertia welding machine to the welding speed, and the pump is then converted to a fixed delivery pump in order to provide a nonfluctuating pressure to power the thrust cylinders for application of the welding pressure.
Inventors
- 👤 Jozef Kiwalle
- 👤 Ira H Sage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:12
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/08; B; B23; B23K; B23K20/00; B23K20/12; B23K20/121; F04B1/00; F04B1/12; F04B1/26; F04B1/30; F04B1/32; F04B1/324
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
165 words
A control for a hydraulic pump of the kind in which the displacement of the pump is varied by changing the angular position of a wobble plate and comprising, a hydraulic servomotor including a servo piston connected to the wobble plate, said servomotor having a fluid pressure chamber on each side of the servo piston, servomotor control means responsive to the output pressure of the pump for controlling the servomotor to cause the pump to operate as a variable displacement pump in one condition of operation, and locking means for locking the servomotor in a predetermined position to cause the pump to operate as a fixed displacement pump in a second condition of operation, said locking means including disabling means for disabling the servomotor control means, said disabling means including first valve means for shutting off the flow of pressurized fluid from the pump to the servomotor control means and second valve means for equalizing the fluid pressures in the chambers of the hydraulic servomotor.
Claim 2
Dependent Claim
165 words
A control for a hydraulic pump of the kind in which the displacement of the pump is varied by changing the angular position of a wobble plate and comprising, a hydraulic servomotor including a servo piston connected to the wobble plate, said servomotor having a fluid pressure chamber on each side of the servo piston, servomotor control means responsive to the output pressure of the pump for controlling the servomotor to cause the pump to operate as a variable displacement pump in one condition of operation, and locking means for locking the servomotor in a predetermined position to cause the pump to operate as a fixed displacement pump in a second condition of operation, said locking means including disabling means for disabling the servomotor control means, said disabling means including first valve means for shutting off the flow of pressurized fluid from the pump to the servomotor control means and second valve means for equalizing the fluid pressures in the chambers of the hydraulic servomotor.
Claim 3
Dependent Claim
33 words
A control as defined in claim 1 wherein the locking means include a shaft attached to the servo piston to hold the piston in a fixed position during the second condition of operation.
Claim 4
Dependent Claim
28 words
A control as defined in claim 2 wherein the locking means include a hydraulic motor having piston means for positioning the shaft in the second condition of operation.
Claim 5
Dependent Claim
221 words
A control for a hydraulic pump of the kind in which the displacement of the pump is varied by changing the angular position of a wobble plate and comprising, a hydraulic servomotor including a servo piston connected to the wobble plate, said servomotor having a fluid pressure chamber on each side of the servo piston, servomotor control means responsive to the output pressure of the pump for controlling the servomotor to cause the pump to operate as a variable displacement pump in one condition of operation, and locking means for locking the servomotor in a predetermined position to cause the pump to operate as a fixed displacement pump in a second condition of operation, said locking means including disabling means for disabling the servomotor control means by equalizing the fluid pressures in the chambers of the hydraulic servomotor, a shaft attached to the servo piston to hold the piston in a fixed position during the second condition of operation, a hydraulic motor having piston means for positioning the shaft in the second condition of operation and wherein the locking means include a fixed stop, the piston means include a first piston member connected to the shaft and a second floating piston member which engages the stop and stops movement of the first piston and shaft in the second condition of operation.
Claim 6
Dependent Claim
221 words
A control for a hydraulic pump of the kind in which the displacement of the pump is varied by changing the angular position of a wobble plate and comprising, a hydraulic servomotor including a servo piston connected to the wobble plate, said servomotor having a fluid pressure chamber on each side of the servo piston, servomotor control means responsive to the output pressure of the pump for controlling the servomotor to cause the pump to operate as a variable displacement pump in one condition of operation, and locking means for locking the servomotor in a predetermined position to cause the pump to operate as a fixed displacement pump in a second condition of operation, said locking means including disabling means for disabling the servomotor control means by equalizing the fluid pressures in the chambers of the hydraulic servomotor, a shaft attached to the servo piston to hold the piston in a fixed position during the second condition of operation, a hydraulic motor having piston means for positioning the shaft in the second condition of operation and wherein the locking means include a fixed stop, the piston means include a first piston member connected to the shaft and a second floating piston member which engages the stop and stops movement of the first piston and shaft in the second condition of operation.
Claim 7
Dependent Claim
50 words
A control as defined in claim 4 wherein the connection between the shaft and the first piston member is a threaded connection which is adjustable to vary the position of the servo piston and thus the amount of the fixed output of the pump in the second condition of operation.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |