US3760840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic modulator
Assignee: Enerpac Tool Group Corp
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Filing: 1972-03-10
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Granted: 1973-09-25
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Expires: 1992-03-10
Abstract
Abstract A dynamic modulator for modulating fluid pressure transients in the hydraulic lines to a hydraulically actuated device, the modulator including a metering piston to control the flow of fluid bypassed through the modulator; a modulating piston positioned to respond to the movement of the metering piston and to control the response of the metering piston; and a bypass duct network connected across the metering piston and including metering valves to control the time interval of response of the metering piston to pressure variations across the metering piston.
Inventors
- 👤 P Gates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:38
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B21/00; F15B21/10; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7771
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
183 words
A dynamic fluid pressure modulator for controlling fluid pressure transients in the hydraulic lines to a hydraulically actuated device, said modulator comprising, a housing having a bore, a chamber at one end of said bore, a first fluid passage connecting said bore to one of the hydraulic lines, a second fluid passage connecting said bore to the other of the hydraulic lines, a metering piston positioned in said bore to control the flow of fluid between said first and second fluid passages, said piston being positioned in said bore to respond to the pressure of fluid in said chamber, means for biasing said piston to a neutral or closed position with respect to said first and second fluid passages, a first bypass duct connecting said first fluid passage to said chamber, a first metering valve in said first bypass duct, a second bypass duct connecting said chamber to said bore on the side of said piston remote from said chamber, a second metering valve in said second bypass duct whereby said metering piston will respond to variations in pressure across said metering piston.
Claim 2
Dependent Claim
183 words
A dynamic fluid pressure modulator for controlling fluid pressure transients in the hydraulic lines to a hydraulically actuated device, said modulator comprising, a housing having a bore, a chamber at one end of said bore, a first fluid passage connecting said bore to one of the hydraulic lines, a second fluid passage connecting said bore to the other of the hydraulic lines, a metering piston positioned in said bore to control the flow of fluid between said first and second fluid passages, said piston being positioned in said bore to respond to the pressure of fluid in said chamber, means for biasing said piston to a neutral or closed position with respect to said first and second fluid passages, a first bypass duct connecting said first fluid passage to said chamber, a first metering valve in said first bypass duct, a second bypass duct connecting said chamber to said bore on the side of said piston remote from said chamber, a second metering valve in said second bypass duct whereby said metering piston will respond to variations in pressure across said metering piston.
Claim 3
Dependent Claim
40 words
The modulator according to claim 1 including a modulating piston positioned in said bore in a spaced relation to said metering piston, said modulating piston respondinG to pressure variations in the space between said metering piston and said modulating piston.
Claim 4
Dependent Claim
20 words
The modulator according to claim 2 including means for biasing said modulating piston to a neutral position in said bore.
Claim 5
Dependent Claim
38 words
The modulator according to claim 3 including a second chamber at the other end of said bore, said second fluid passage being connected to said second chamber, and a third fluid passage connecting said chamber to said bore.
Claim 6
Dependent Claim
21 words
The modulator according to claim 1 wherein said biasing means comprises a bidirectional metering spring assembly positioned in said first chamber.
Claim 7
Dependent Claim
155 words
A dynamic modulator for controlling fluid pressure transients in the hydraulic lines to a hydraulically actuated device, said modulator comprising, a housing having a bore, a first fluid passage connecting said bore to one of the hydraulic lines, a second fluid passage connecting said bore to the other of the hydraulic lines, a metering piston positioned in said bore to control the flow of fluid between said first fluid passage and said second fluid passage, a modulating piston in said bore positioned in a spaced relation to said metering piston and being connected to respond to the pressure in said second passage, a first fluid bypass duct connecting said first passage to the end of said bore adjacent to said metering piston, and a metering valve in said first fluid bypass duct, whereby said metering piston responds to a fluid pressure transient in the hydraulic lines to bypass fluid through said first and second passages.
Claim 8
Dependent Claim
155 words
A dynamic modulator for controlling fluid pressure transients in the hydraulic lines to a hydraulically actuated device, said modulator comprising, a housing having a bore, a first fluid passage connecting said bore to one of the hydraulic lines, a second fluid passage connecting said bore to the other of the hydraulic lines, a metering piston positioned in said bore to control the flow of fluid between said first fluid passage and said second fluid passage, a modulating piston in said bore positioned in a spaced relation to said metering piston and being connected to respond to the pressure in said second passage, a first fluid bypass duct connecting said first passage to the end of said bore adjacent to said metering piston, and a metering valve in said first fluid bypass duct, whereby said metering piston responds to a fluid pressure transient in the hydraulic lines to bypass fluid through said first and second passages.
Claim 9
Dependent Claim
28 words
The modulator according to claim 6 including means for bidirectionally biasing said metering piston to a closed position with respect to said first passage and said second passage.
Claim 10
Dependent Claim
21 words
The modulator according to claim 6 including means for bidirectionally biasing said modulating piston to a neutral position in said bore.
Claim 11
Dependent Claim
62 words
The modulator according to claim 6 including a first chamber at one end of said bore connected to said first bypass duct and a second chamber at the other end of said bore connected to said second fluid passage, said metering piston responding to pressure changes in said first chamber and said modulating piston responding to pressure changes in said second chamber.
Claim 12
Dependent Claim
32 words
The modulator according to claim 6 including a second bypass duct connecting said one end of said bore to the space in said bore between said metering piston and said modulating piston.
Claim 13
Dependent Claim
24 words
The modulator according to claim 10 including a metering valve in said second bypass duct tocontrol the flow rate through said second bypass duct.
References Cited (Backward Citations)
US3138072A
Cited
US3378028A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |