US3744508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-regulating valve,particularly for fuel-oil pumps
Assignee: Danfoss AS
•
Filing: 1969-08-05
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Granted: 1973-07-10
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Expires: 1989-08-05
Abstract
Abstract The invention relates to a pressure regulating valve assembly for pumps. The assembly includes two relatively movable pistons with one being a setting piston acted upon by supply pressure and a rated spring and the other being a regulating piston which controls a return orifice and is acted upon by the supply pressure and a differential spring. The supply pressure for the regulating piston is delivered through a modulated restrictor passage with the pressure drop in the restrictor passage corresponding to the quantity of pressurized fluid delivered therethrough. The regulating piston is hydraulically loaded by only a differential pressure which provides a greater ease in movement and allows a relatively weak differential spring to be utilized.
Inventors
- 👤 G Hansen
- 👤 J Petersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:21
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/04; G05D16/06; G05D16/08; G05D16/10; G05D16/101; G05D16/109; Y; Y10; Y10T; Y10T137/00; Y10T137/2496; Y10T137/2559; Y10T137/2574; Y10T137/2579; Y10T137/2587; Y10T137/2605; Y10T137/2607
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
137 words
Pressure regulating apparatus comprising a housing having a cylindrical bore, setting and regulating pistons in said bore forming a first chamber between said pistons and a second chamber on the other side of said regulating piston, a rated spring biasing said setting piston in one direction and a diffeRential spring biasing said regulating piston in the opposite direction, a supply inlet in said housing opening into said first chamber between said pistons, a discharge outlet in said housing have fluid communication with said second chamber, restrictor passage means between said chambers, and a return outlet in said housing having fluid communication with said second chamber, said return outlet having a valve opening cooperable with said regulating piston to form a regulating valve, said regulating valve being openable upon movement of said regulating piston in said opposite direction.
Claim 2
Dependent Claim
137 words
Pressure regulating apparatus comprising a housing having a cylindrical bore, setting and regulating pistons in said bore forming a first chamber between said pistons and a second chamber on the other side of said regulating piston, a rated spring biasing said setting piston in one direction and a diffeRential spring biasing said regulating piston in the opposite direction, a supply inlet in said housing opening into said first chamber between said pistons, a discharge outlet in said housing have fluid communication with said second chamber, restrictor passage means between said chambers, and a return outlet in said housing having fluid communication with said second chamber, said return outlet having a valve opening cooperable with said regulating piston to form a regulating valve, said regulating valve being openable upon movement of said regulating piston in said opposite direction.
Claim 3
Dependent Claim
43 words
Pressure regulating apparatus according to claim 1 wherein said restrictor passage means has a valve opening cooperable with at least one of said pistons to form a restrictor valve, said restrictor valve being openable upon movement of at least one of said pistons.
Claim 4
Dependent Claim
54 words
Pressure regulating apparatus according to claim 2 wherein said pistons are arranged coaxially with their adjacent ends in part defining said first chamber and with their other two ends being in respective engagement with said rated and differential springs, said restrictor passage means being formed at least in part in one of said pistons.
Claim 5
Dependent Claim
34 words
Pressure regulating apparatus according to claim 1 including a closure member cooperable with said discharge outlet to form a cut-off valve, said cut-off valve being biasable in a closing direction by said rated spring.
Claim 6
Dependent Claim
58 words
Pressure regulating apparatus according to claim 4 wherein said regulating piston and said closure member have mutually engagable abutment means which form a lost motion coupling therebetween, said regulating piston being movable by said closure member in said opposite direction, said closure member being movable in said one direction by said rated spring independently of said regulating piston.
Claim 7
Dependent Claim
20 words
Pressure regulating apparatus according to claim 5 including closure spring means for biasing said closure member in said opposite direction.
Claim 8
Dependent Claim
16 words
Pressure regulating apparatus according to claim 5 wherein said abutment means includes a resilient sealing member.
Claim 9
Dependent Claim
35 words
Pressure regulating apparatus according to claim 5 wherein said abutment means includes an annularly shaped backing member for said regulating piston, and an annularly shaped seal disposed between said setting piston and said regulating piston.
Claim 10
Dependent Claim
23 words
Pressure regulating apparatus according to claim 4 including damping means between said closure member and said setting piston for damping relative movement therebetween.
Claim 11
Dependent Claim
56 words
Pressure regulating apparatus according to claim 9 wherein said damping means includes a bore in said setting piston for receving said closure member, said bore being closed at one end to form a damping chamber, means for supplying pressurized fluid to said damping chamber, and throttle means for throttling pressurized fluid supplied to said damping chamber.
Claim 12
Dependent Claim
56 words
Pressure regulating apparatus according to claim 10 wherein said closure member has a cylindrically shaped external surface and a clearance is provided between said external surface and said bore surface, said restrictor passage means being formed in said closure member, said clearance providing a throttled fluid communication path between said restrictor passage means and damping chamber.
Claim 13
Dependent Claim
41 words
Pressure regulating apparatus according to claim 11 including an annular groove in said closure member external surface, said annular groove having fluid communication with said restrictor passage means to provide pressurized fluid for flow through said clearance to said damping chamber.
Claim 14
Dependent Claim
32 words
Pressure regulating apparatus according to claim 10 wherein said bore is closed at one end by a perforate plate, and a supporting plate interposed between said perforate plate and said rated spring.
Claim 15
Dependent Claim
36 words
Pressure regulating apparatus according to claim 4 wherein said restrictor passage means is formed in said closure member, said closure member cooperating with said setting piston to vary the flow resistance of said restrictor passage means.
Claim 16
Dependent Claim
29 words
Pressure regulating apparatus according to claim 4 wherein said regulating piston has a central bore, said closure member having a cylindrically shaped external surface surrounded by said central bore.
Claim 17
Dependent Claim
64 words
Pressure regulating apparatus according to claim 4 including an annularly shaped recess surrounding said discharge outlet, an O-ring disposed in said recess, a central bore in said closure member, and a tube in said discharge outlet surrounded by said O-ring and extending into said closure member bore so as to retain said O-ring during movement of said closure member relative to said discharge outlet.
Claim 18
Dependent Claim
17 words
Pressure regulating apparatus according to claim 16 in which said tube forms an axially extending flow passage.
Claim 19
Dependent Claim
55 words
Pressure regulating apparatus according to claim 1 wherein said setting and regulating pistons have outside diameters of the same size, said regulating piston having a central bore, said setting piston having an axially extending portion of lesser diameter than said central bore, said axially extending portion being at least partially surrounded by said central bore.
Claim 20
Dependent Claim
50 words
Pressure regulating apparatus according to claim 18 wherein said regulating piston has a second bore of smaller diameter than said central bore and an annularly shaped base surface connecting said bores, and an annularly shaped seal pressed against said base surface by said axially extending portion of said setting piston.
Claim 21
Dependent Claim
25 words
Pressure regulating apparatus according to claim 1 including a pump suction pipe, and a branch pipe extending from said suction pipe to said return outlet.
Claim 22
Dependent Claim
22 words
Pressure regulating apparatus according to claim 1 including a sump, and a return pipe extending from said sump to said return outlet.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |