US3662544A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combined auxiliary power and engine starter systems
Assignee: Plessey Overseas Ltd
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Filing: 1970-05-15
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Granted: 1972-05-16
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Expires: 1990-05-15
Abstract
Abstract To permit an auxiliary power unit to start an engine without drastic temporary reduction of the running speed of that unit, the engine is coupled to the auxiliary power unit by a differential gear drive whose third element drives a gear pump having in that outlet which is the delivery outlet when the auxiliary power unit drives the engine, a normally unloaded pressure retaining valve which, to produce starting torque for the engine, can be loaded to build-up a preset delivery pressure. A pre-loaded pressure-retaining valve may be provided in the other pump outlet in order to permit transmission of torque from the main engine to the auxiliary power unit, both valves being by-passed in the respectively reverse direction by non-return valves.
Inventors
- 👤 Peter Burno Kahn
- 👤 Norman Frederick North
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:39
CPC Classifications
F; F16; F16H; F16H37/00; F16H2700/00; F16H2700/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
195 words
An auxiliary-power system for use in conjunction with a combustion engine to drive auxiliary equipment and to provide starting power for such engine, which comprises in combination: a prime mover, an output shaft for the drive of such auxiliary equipment; drive means opposed between said output shaft and the prime mover to drive said output shaft at a speed proportional to that of the prime mover; a starting-power output-shaft; a threeelement differential gear drive two of the three elements of which are respectively coupled to the prime mover and to the starting power output shaft; a positive-displacement pump coupled to the third element of said differential gear drive and arranged to deliver liquid to a low-pressure point; a pressure-retaining valve operable to oppose a pressure to the flow of liquid from said pump to said low-pressure point; and loading means for said pressure-retaining valve operable to load the said valve with a force which is adjustable from substantially zero to a maximum so determined as to limit the torque load applied by said pump to the prime mover through said differential-gear drive to a value lower than the torque output available from the prime mover.
Claim 2
Dependent Claim
195 words
An auxiliary-power system for use in conjunction with a combustion engine to drive auxiliary equipment and to provide starting power for such engine, which comprises in combination: a prime mover, an output shaft for the drive of such auxiliary equipment; drive means opposed between said output shaft and the prime mover to drive said output shaft at a speed proportional to that of the prime mover; a starting-power output-shaft; a threeelement differential gear drive two of the three elements of which are respectively coupled to the prime mover and to the starting power output shaft; a positive-displacement pump coupled to the third element of said differential gear drive and arranged to deliver liquid to a low-pressure point; a pressure-retaining valve operable to oppose a pressure to the flow of liquid from said pump to said low-pressure point; and loading means for said pressure-retaining valve operable to load the said valve with a force which is adjustable from substantially zero to a maximum so determined as to limit the torque load applied by said pump to the prime mover through said differential-gear drive to a value lower than the torque output available from the prime mover.
Claim 3
Dependent Claim
33 words
An auxiliary-power system as claimed in claim 1, which further includes a displacement-type motor drivingly coupled to said starting-power output shaft and connected to be fed by fluid delivered by said positive-displacement pump.
Claim 4
Dependent Claim
159 words
An auxiliary-power system as claimed in claim 1, which further comprises a second pressure-retaining valve, arranged in a line connecting the point of low pressure with the other side of the pump and operable by flow in the opposite direction so as to oppose a torque resistance to rotation of the third element of the differential-gear drive in the opposite direction when the starting-power output shaft tends to run faster than the speed at which it tends to be driven by the auxiliary power unit via the differential gear drive, and two back-flow-operated non-return valves respectively by-passing the two pressure-retaining valves to permit unrestricted flow past each pressure-retaining valve in the direction opposite to that operative to open the retaining valve, so that during the starting of an engine the by-pass valve of the last-mentioned pressure-retaining valve and during transmission of torque from the engine to the auxiliary-power unit the non-return valve by-passing the first-mentioned pressure-retaining valve is open.
Claim 5
Dependent Claim
47 words
A system as claimed in claim 1 for use in connection with a plurality of engines, which includes for each engine a separate starting-power output shaft, a separate three-element differential gear drive and, in conjunction with said differential gear drive, a separate positive-displacement pump and pressure-retaining valve.
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) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |