Patent US1334192A successfully refreshed from Google Patents.
Patent US3788075A successfully refreshed from Google Patents.
US3788075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve mechanism
Assignee: Borg Warner Corp
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Filing: 1972-07-13
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Granted: 1974-01-29
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Expires: 1992-07-13
Abstract
Abstract A pressure equalizer valve and reversible flow logic system are provided for reversible fluid motors that are connected in series. The pressure equalizer valve is effective to bypass a small quantity of fluid from the source of fluid pressure to the junction between the motors or from the junction between the motors to a low pressure conduit. This bypassing of fluid is effective to provide equal or proportional operating pressures across the fluid motors, to prevent cavitation of the downstream fluid motor, and to act as a fluid differential for the fluid motors when propelling a vehicle that is making a turn. The logic system provides reversible flow fluid communication between the fluid motors and the equalizer valve so that the equalizer valve functions properly when the fluid motors are reversed.
Inventors
- 👤 J Holdeman
- 👤 K Mcmillen
- 👤 L Mcmillan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:39
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/44; F16H61/452; F16H61/4043
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
245 words
A source of fluid pressure including a pump adapted to supply fluid pressure to a hydraulic system and to receive exhaust fluid therefrom; a first reversible fluid motor and a second reversible fluid motor connected in series thereby providing a first inletoutlet port in said first motor, a second inlet-outlet port in said second motor, and an intermediate junction at the connection between said motors; conduit means connecting said first inlet-outlet port to said source to receive pressurized fluid therefrom and connecting said second inlet-outlet port to said source to return exhaust fluid thereto; reversing means adapted to selectively change the flow of said pump so that said second inlet-outlet port receives pressurized fluid from said source and said first inlet-outlet port returns exhaust fluid to said source; reversible flow logic means having a logic port, a first input port connected to said first inlet-outlet port, having a second input port connected to said second inlet-outlet port, and effective to establish reversible flow fluid communication between said logic port and whichever of said input ports is receiving pressurized fluid from said source; and a pressure equalizer valve connected to said logic port, to said intermediate junction, and adapted to bypass fluid from said logic port to said intermediate junction and from said intermediate junction to said source depending upon the relative fluid pressures in said logic port and in said intermediate junction, and effective to control the pressure differentials across said first and second motors.
Claim 2
Dependent Claim
245 words
A source of fluid pressure including a pump adapted to supply fluid pressure to a hydraulic system and to receive exhaust fluid therefrom; a first reversible fluid motor and a second reversible fluid motor connected in series thereby providing a first inletoutlet port in said first motor, a second inlet-outlet port in said second motor, and an intermediate junction at the connection between said motors; conduit means connecting said first inlet-outlet port to said source to receive pressurized fluid therefrom and connecting said second inlet-outlet port to said source to return exhaust fluid thereto; reversing means adapted to selectively change the flow of said pump so that said second inlet-outlet port receives pressurized fluid from said source and said first inlet-outlet port returns exhaust fluid to said source; reversible flow logic means having a logic port, a first input port connected to said first inlet-outlet port, having a second input port connected to said second inlet-outlet port, and effective to establish reversible flow fluid communication between said logic port and whichever of said input ports is receiving pressurized fluid from said source; and a pressure equalizer valve connected to said logic port, to said intermediate junction, and adapted to bypass fluid from said logic port to said intermediate junction and from said intermediate junction to said source depending upon the relative fluid pressures in said logic port and in said intermediate junction, and effective to control the pressure differentials across said first and second motors.
Claim 3
Dependent Claim
28 words
The system as claimed in claim 1 in which said reversing means includes a control valve interposed in said conduit means between said source and said inlet-outlet ports.
Claim 4
Dependent Claim
29 words
The system as claimed in claim 1 in which said reversing means includes displacement control means connected to said pump and adapted to reverse the flow through said pump.
Claim 5
Dependent Claim
93 words
The system as claimed in claim 1 in which said pump has first and second ports, said conduit means connects one of said pump ports to one of said input-output ports and the other of said pump ports to the other of said input-output ports, and said motors are connected to and drive a load, whereby dynamic braking is achieved and overrun of said load restrained when said load and said motors attempt to return fluid to said pump at a greater flow rate than said pump is supplying fluid to said motors.
Claim 6
Dependent Claim
52 words
The system as claimed in claim 4 in which said reversible flow logic means is pressure responsive to fluid pressures in said conduits, whereby said logic means is effective to actuate said equalizer valve and said equalizer valve is effective to control the pressure differentials across said motor during said dynamic braking.
Claim 7
Dependent Claim
55 words
The system as claimed in claim 4 which includes second logic means connected to said equalizer valve, connected to said first inlet-outlet port, connected to said second inlet-outlet port, and adapted tO allow said equalizer valve to bypass fluid from said intermediate junction to whichever of said inlet-outlet ports contains the lower f uid pressure.
Claim 8
Dependent Claim
19 words
The system as claimed in claim 6 in which said second logic means includes first and second check valves.
Claim 9
Dependent Claim
20 words
The system as claimed in claim 1 in which said reversible flow logic means includes a three port shuttle valve.
Claim 10
Dependent Claim
67 words
The system as claimed in claim 1 in which said pressure equalizer valve includes a first fluid responsive area operatively connected to said logic port and a second fluid responsive area operatively connected to said intermediate junction, whereby th relative size of said fluid responsive areas and the relative pressures in said logic port and in said intermediate junction are effective to control the bypassing of fluid.
Claim 11
Dependent Claim
25 words
The system as claimed in claim 9 in which said second fluid responsive area is substantially twice as large as said first fluid responsive area.
Claim 12
Dependent Claim
95 words
The system as claimed in claim 9 in which said pressure equalizer valve includes a valving piston, said first fluid responsive area is adapted to move said valving piston to a first operating position wherein fluid is bypassed from said logic port to said intermediate junction, said second fluid responsive area is adapted to move said valving piston to a second operating position wherein fluid is bypassed from said intermediate junction to said source, and resilient bias force means assists one of said areas in moving said valving piston toward one of said operating positions.
Claim 13
Dependent Claim
93 words
The system as claimed in claim 11 which includes charging pressure means being adapted to maintain above atmospheric pressure in said conduit means, said valving piston comprises a stepped cylinder which includes projected end areas comprising said first and second areas and a third fluid responsive area, said third area is operatively connected to said conduit means containing said charging pressure and is responsive thereto, and said resilient bias means is a spring, said spring being adapted to substantially balance the force developed by said charging pressure being applied to said third area.
Claim 14
Dependent Claim
28 words
The system as claimed in claim 1 in which said source includes a sump and said pressure equalizer valve bypasses fluid from said intermediate junction to said sump.
Claim 15
Dependent Claim
40 words
The system as claimed in claim 1 which includes a series parallel valve connected to said conduit means and into said connection between said motors and adapted to selectively change said series connection of said motors to a parallel connection.
Claim 16
Dependent Claim
29 words
The system as claimed in claim 14 in which said series parallel valve blocks operation of said equalizer valve when said series parallel valve connects said motors in parallel.
Claim 17
Dependent Claim
92 words
The system as claimed in claim 14 in which said series parallel valve includes a valve body having a spool bore therein and a valve spool slidably fitted into said bore, said body includes a first inlet-outlet port intersecting said bore, a second inlet-outlet port spaced longitudinally from said first inlet-outlet port and intersecting said bore, first and second series parallel ports intersecting said bore and interposed between said first and second inlet-outlet ports, and an intermediate junction port intersecting said bore and interposed between said first and second series parallel ports.
Claim 18
Dependent Claim
78 words
The system as claimed in claim 16 in which said valve spool includes three reduced diameter portions and two land portions therebetween, and said two land portions are effective to isolate said intermediate junction port from said series parallel ports when one of said reduced diameter portions is connecting said first series parallel port to said first inlet-outlet port and another of said reduced diameter portions is connecting said second series parallel port to said second inlet-outlet port.
Claim 19
Dependent Claim
29 words
The system as claimed in claim 1 which includes fluid restrictor means interposed in said system and adapted to limit the ability of said equalizer valve to bypass fluid.
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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |