US3637327A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pump
Assignee: Borg Warner Corp
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Filing: 1969-11-24
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Granted: 1972-01-25
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Expires: 1989-11-24
Abstract
Abstract A variable displacement pump is provided with a temperature compensated displacement compensator valve adjusted to obtain a desired constant pressure output under variable fluid medium temperature conditions. The valve incorporates, in addition to spring biasing means, temperature responsive means which vary the force applied to the spring in response to temperature changes in the environment.
Inventors
- 👤 Emil A Kubiak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:58
CPC Classifications
F; F04; F04B; F04B1/00; F04B1/12; F04B1/26; F04B1/30; F04B1/32; F04B1/328; F04B49/00; F04B49/08; F04B49/10
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
203 words
In a variable displacement fluid device wherein a plurality of pistons are arranged for reciprocation each in a cylinder barrel and the strokes of each is variable to vary the displacement of the device, and wherein there is a compensator valve member connected to the fluid inlet of said device and to the outlet of said device so as to control the length of said strokes in response to the outlet pressure and in accordance with output flow requirements thereby to maintain the outlet pressure substantially constant throughout the range from zero displacement to full displacement, said valve including a spool subject to said outlet pressure at one end and a coil spring for biasing said spool against said outlet pressure, and in which undesirable variations are likely to occur in the outlet pressure as a result of operating temperature changes, the improvement which comprises: a temperature responsive bimetallic spring, in series with and in addition to said coil spring, for varying the compression on said coil spring in response to changes in temperature to provide, by the series combination, a substantially uniform net biasing force on said spool in order to maintain the outlet pressure substantially constant over the working temperature range.
Claim 2
Dependent Claim
203 words
In a variable displacement fluid device wherein a plurality of pistons are arranged for reciprocation each in a cylinder barrel and the strokes of each is variable to vary the displacement of the device, and wherein there is a compensator valve member connected to the fluid inlet of said device and to the outlet of said device so as to control the length of said strokes in response to the outlet pressure and in accordance with output flow requirements thereby to maintain the outlet pressure substantially constant throughout the range from zero displacement to full displacement, said valve including a spool subject to said outlet pressure at one end and a coil spring for biasing said spool against said outlet pressure, and in which undesirable variations are likely to occur in the outlet pressure as a result of operating temperature changes, the improvement which comprises: a temperature responsive bimetallic spring, in series with and in addition to said coil spring, for varying the compression on said coil spring in response to changes in temperature to provide, by the series combination, a substantially uniform net biasing force on said spool in order to maintain the outlet pressure substantially constant over the working temperature range.
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) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |