Patent US4554947A successfully refreshed from Google Patents.
US4554947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load recall valve
Assignee: National Oilwell Varco LP
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Filing: 1984-10-29
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Granted: 1985-11-26
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Expires: 2004-10-29
Abstract
Abstract A load recall valve has a mechanical memory which coordinates the releasing of the brake with the system pressure. The mechanical memory requires that the system pressure be at least equal to the system pressure just prior to when the brake was set. Setting of the brake prior to the load being taken off the system causes the memory to be activated. Setting of the brake after the load is taken off the system causes the stored memory portion to be erased.
Inventors
- 👤 Jasper E. Cobb, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:58
CPC Classifications
B; B66; B66D; B66D5/00; B66D5/02; B66D5/24; B66D5/26; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86622; Y10T137/8663; Y10T137/87169; Y10T137/87217; Y10T137/87225
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
441 words
A load recall valve, comprising: (a) a hollow valve body having a first pressure inlet, a second pressure inlet, a pilot pressure inlet and a pilot pressure outlet; (b) said pilot pressure inlet is proximate said pilot pressure outlet; (c) sleeve means slidably disposed in said body and including means for selectively isolating said pilot pressure inlet from said pilot pressure outlet and further including a longitudinally extending aperture therethrough communicating with a plurality of generally transverse orifices for connecting said aperture to said pilot pressure inlet; (d) spool means slidably disposed in said aperture and including means for interconnecting said orifices for thereby permitting selective interconnection of said pilot pressure inlet with said pilot pressure outlet; (e) first pressure receiving means slidably disposed within said body communicating with said first pressure inlet and engagable with said spool means and said sleeve means whereby application of pressure to said first pressure receiving means causes sliding thereof in a first direction and associated sliding of said spool means and subsequently causes sliding of said sleeve means for thereby establishing interconnection between said pilot outlet and said pilot inlet; (f) resilient means associated with said first pressure receiving means for causing sliding of said first pressure receiving means in a second direction opposite to said first direction upon cessation of application of pressure thereto; (g) second pressure receiving means slidably disposed within said body and communicating with said second inlet and adapted for sliding in said first direction upon engagement with said sleeve means and for being displaced in said second direction by application of pressure to said second pressure inlet; and (h) biasing means associated with said second pressure receiving means and said spool means for displacing said spool means in said second direction whereby application of pressure to said first pressure receiving means causes at least said spool means to slide in said first direction to a position associated with the amount of pressure applied for thereby interconnecting said pilot pressure inlet with said pilot pressure outlet and whereby cessation of application of pressure to said second pressure receiving means prior to cessation of application of pressure to said first pressure receiving means causes said sleeve means to remain in said position while said biasing means causes said spool means to slide a distance sufficient to isolate said pilot inlet from said pilot outlet and thereby provide a stored memory position and further whereby cessation of pressure application to said second pressure means after cessation of pressure application to said first pressure receiving means causes said sleeve means to slide in said second direction and thereby erase said stored memory position.
Claim 2
Dependent Claim
441 words
A load recall valve, comprising: (a) a hollow valve body having a first pressure inlet, a second pressure inlet, a pilot pressure inlet and a pilot pressure outlet; (b) said pilot pressure inlet is proximate said pilot pressure outlet; (c) sleeve means slidably disposed in said body and including means for selectively isolating said pilot pressure inlet from said pilot pressure outlet and further including a longitudinally extending aperture therethrough communicating with a plurality of generally transverse orifices for connecting said aperture to said pilot pressure inlet; (d) spool means slidably disposed in said aperture and including means for interconnecting said orifices for thereby permitting selective interconnection of said pilot pressure inlet with said pilot pressure outlet; (e) first pressure receiving means slidably disposed within said body communicating with said first pressure inlet and engagable with said spool means and said sleeve means whereby application of pressure to said first pressure receiving means causes sliding thereof in a first direction and associated sliding of said spool means and subsequently causes sliding of said sleeve means for thereby establishing interconnection between said pilot outlet and said pilot inlet; (f) resilient means associated with said first pressure receiving means for causing sliding of said first pressure receiving means in a second direction opposite to said first direction upon cessation of application of pressure thereto; (g) second pressure receiving means slidably disposed within said body and communicating with said second inlet and adapted for sliding in said first direction upon engagement with said sleeve means and for being displaced in said second direction by application of pressure to said second pressure inlet; and (h) biasing means associated with said second pressure receiving means and said spool means for displacing said spool means in said second direction whereby application of pressure to said first pressure receiving means causes at least said spool means to slide in said first direction to a position associated with the amount of pressure applied for thereby interconnecting said pilot pressure inlet with said pilot pressure outlet and whereby cessation of application of pressure to said second pressure receiving means prior to cessation of application of pressure to said first pressure receiving means causes said sleeve means to remain in said position while said biasing means causes said spool means to slide a distance sufficient to isolate said pilot inlet from said pilot outlet and thereby provide a stored memory position and further whereby cessation of pressure application to said second pressure means after cessation of pressure application to said first pressure receiving means causes said sleeve means to slide in said second direction and thereby erase said stored memory position.
Claim 3
Dependent Claim
43 words
The valve as defined in claim 1, wherein: (a) said first pressure inlet is longitudinally aligned with said second pressure inlet; and, (b) said pilot pressure inlet and said pilot pressure outlet are each generally transverse to said first and second pressure inlets.
Claim 4
Dependent Claim
33 words
The valve as defined in claim 1, wherein: (a) resilient seal means associated with said sleeve means and engagable with said body for isolating said pilot pressure inlet from said pilot pressure outlet.
Claim 5
Dependent Claim
38 words
The valve as defined in claim 3, wherein: (a) said resilient seal means have a coefficient of sliding friction sufficient to permit said spool means to slide in said aperture without causing associated sliding of said sleeve means.
Claim 6
Dependent Claim
67 words
The valve as defined in claim 3, wherein: (a) a plurality of radially extending spaced flanges are disposed about the periphery of said sleeve means and each of said flanges includes means for seating one of said resilient seal means; (b) a plurality of flow channels are disposed about said sleeve means and extend between said flange means; and, (c) said orifices communicate with said flow channels.
Claim 7
Dependent Claim
76 words
The valve as defined in claim 1, wherein: (a) said spool means includes a pair of coaxial flanges interconnected by a coaxial shaft; (b) a coaxial extension extends from one of said flanges and is adapted for engagement with said first pressure receiving means; and, (c) said shaft has a diameter less than the diameter of said flanges for thereby providing an annular flow channel for connecting said pilot pressure inlet with said pilot pressure outlet.
Claim 8
Dependent Claim
28 words
The valve as defined in claim 1, wherein: (a) securing means are disposed in said sleeve and spaced from said spool means for positively positioning said biasing means.
Claim 9
Dependent Claim
15 words
The valve as defined in claim 7, wherein: (a) said biasing means includes a spring.
Claim 10
Dependent Claim
54 words
The valve as defined in claim 1, wherein: (a) said body is closed at one end thereof by a low pressure closure cap; (b) said second pressure inlet is disposed in said low pressure closure cap; and, (c) said second pressure receiving means has a portion thereof slidably disposed within said second pressure inlet.
Claim 11
Dependent Claim
76 words
The valve as defined in claim 9, wherein: (a) said second pressure inlet includes an aperture of substantial length through said low pressure closure cap; (b) said second pressure receiving means includes a piston having a shaft portion thereof slidably disposed within said low pressure closure cap aperture; and, (c) said shaft has sufficient length so as not to extend beyond said low pressure closure cap when said piston has been displaced in said first direction.
Claim 12
Dependent Claim
57 words
The valve as defined in claim 9, wherein: (a) said body is closed at an end opposite said one end by a high pressure closure cap; (b) said first pressure inlet is disposed in said high pressure closure cap; and, (c) said first pressure receiving means has a portion thereof slidably disposed in said first presssure inlet.
Claim 13
Dependent Claim
66 words
The valve as defined in claim 11, wherein: (a) said first pressure receiving means includes a displaceable cylinder having an extension thereof engagable with said spool means and said sleeve means; (b) recess disposed in said cylinder and aligned with said first pressure inlet; and, (c) said first pressure receiving means associated with said first pressure inlet for displacing said cylinder upon application of pressure thereto.
Claim 14
Dependent Claim
16 words
The valve as defined in claim 12, wherein: (a) said resilient means disposed about said cylinder.
Claim 15
Dependent Claim
53 words
The valve as defined in claim 13, wherein: (a) a peripheral flange extends around said cylinder at an end thereof adjacent said high pressure closure cap; and, (b) a spring is disposed about said cylinder and has a portion thereof engagable with said cylinder flange for displacing said cylinder in said second direction.
Claim 16
Dependent Claim
29 words
The valve as defined in claim 12, wherein: (a) said spool means and said cylinder each includes an aligned cooperating aperture for preventing pressure build up in said body.
Claim 17
Dependent Claim
17 words
The valve as defined in claim 1, wherein: (a) a drain port communicates with said hollow body.
Claim 18
Dependent Claim
444 words
A load recall valve, comprising: (a) a valve body having first and second chambers therein and including means interconnecting said chambers; (b) first and second pressure inlets disposed in said body and each of said inlets communicating with one of said chambers; (c) a displaceable cylinder disposed in said first chamber and including an extension thereof displaceable through said means and said cylinder including a recess aligned with said first inlet; (d) a displaceable piston disposed in said recess and engagable with said extension and cooperating with said inlet for displacing said cylinder in a first direction when pressure is applied to said first inlet; (e) biasing means associated with said cylinder and adapted for displacing said cylinder and said piston thereby in a second direction opposite to said first direction when pressure application to said first inlet ceases; (f) a pilot inlet and a pilot outlet are disposed in said body and communicate with said second chamber; (g) sleeve means having a longitudinal aperture therethrough aligned with said extension and slidably disposed in said second chamber and engagable with said extension and adapted for being displaced thereby; (h) said sleeve means includes means for selectively isolating said pilot inlet from said pilot outlet and further includes means for connecting said pilot inlet with said sleeve aperture; (i) spool means slidably disposed within said sleeve aperture and engagable with said extension and adapted for being displaced thereby and including means cooperating with said means for connecting for thereby connecting said pilot inlet with said pilot outlet upon displacement thereof; (j) piston means slidably associated with said second inlet and engagable with said sleeve means and adapted for shifting said sleeve means in a second direction upon application of pressure to said second inlet; and, (k) biasing means associated with said second inlet piston and with said spool means for sliding said spool means in said second direction upon cessation of pressure application to said first inlet whereby at least said spool means is displaced to a position associated with the amount of pressure applied and whereby cessation of pressure application to said second inlet prior to cessation of pressure application to said first inlet causes said sleeve means to be maintained in said position while said biasing means displaces said spool means a distance sufficient to isolate said pilot inlet from said pilot outlet for thereby providing a stored memory position and further whereby cessation of pressure application to said second inlet subsequent to the cessation of pressure application to said first inlet causes said spool means and said sleeve to be displaced in said second direction and thereby erases said stored memory position.
Claim 19
Dependent Claim
444 words
A load recall valve, comprising: (a) a valve body having first and second chambers therein and including means interconnecting said chambers; (b) first and second pressure inlets disposed in said body and each of said inlets communicating with one of said chambers; (c) a displaceable cylinder disposed in said first chamber and including an extension thereof displaceable through said means and said cylinder including a recess aligned with said first inlet; (d) a displaceable piston disposed in said recess and engagable with said extension and cooperating with said inlet for displacing said cylinder in a first direction when pressure is applied to said first inlet; (e) biasing means associated with said cylinder and adapted for displacing said cylinder and said piston thereby in a second direction opposite to said first direction when pressure application to said first inlet ceases; (f) a pilot inlet and a pilot outlet are disposed in said body and communicate with said second chamber; (g) sleeve means having a longitudinal aperture therethrough aligned with said extension and slidably disposed in said second chamber and engagable with said extension and adapted for being displaced thereby; (h) said sleeve means includes means for selectively isolating said pilot inlet from said pilot outlet and further includes means for connecting said pilot inlet with said sleeve aperture; (i) spool means slidably disposed within said sleeve aperture and engagable with said extension and adapted for being displaced thereby and including means cooperating with said means for connecting for thereby connecting said pilot inlet with said pilot outlet upon displacement thereof; (j) piston means slidably associated with said second inlet and engagable with said sleeve means and adapted for shifting said sleeve means in a second direction upon application of pressure to said second inlet; and, (k) biasing means associated with said second inlet piston and with said spool means for sliding said spool means in said second direction upon cessation of pressure application to said first inlet whereby at least said spool means is displaced to a position associated with the amount of pressure applied and whereby cessation of pressure application to said second inlet prior to cessation of pressure application to said first inlet causes said sleeve means to be maintained in said position while said biasing means displaces said spool means a distance sufficient to isolate said pilot inlet from said pilot outlet for thereby providing a stored memory position and further whereby cessation of pressure application to said second inlet subsequent to the cessation of pressure application to said first inlet causes said spool means and said sleeve to be displaced in said second direction and thereby erases said stored memory position.
Claim 20
Dependent Claim
23 words
The valve as defined in claim 17, wherein: (a) said chambers, said means and said first and second pressure inlets are coaxially aligned.
Claim 21
Dependent Claim
24 words
The valve as defined in claim 18, wherein: (a) said pilot inlet and said pilot outlet are disposed generally transverse to said second chamber.
Claim 22
Dependent Claim
62 words
The valve as defined in claim 17, wherein: (a) said first chamber is closed by a high pressure closure cap; (b) an aperture disposed in said high pressure closure cap coaxially with said first pressure inlet; and, (c) said piston has a portion thereof slidably disposed within said high pressure closure cap aperture and adapted for being guided therein during displacement thereof.
Claim 23
Dependent Claim
46 words
The valve as defined in claim 20, wherein: (a) said cylindrical recess being cylindrical disposed in said cylinder coaxial with said first pressure inlet; and, (b) said high pressure closure cap includes an extension thereof received in said recess for guiding said cylinder during displacement thereof.
Claim 24
Dependent Claim
47 words
The valve as defined in claim 21, wherein: (a) a peripheral flange extends around said cylinder adjacent said high pressure closure cap; and, (b) said biasing means disposed around said cylinder and a portion thereof engagable with said flange for displacing said cylinder in said second direction.
Claim 25
Dependent Claim
44 words
The valve as defined in claim 17, wherein: (a) a plurality of longitudinally spaced resilient seal means disposed about the periphery of said sleeve means and engagable with said body for permitting displacement of said spool means without associated displacement of said sleeve means.
Claim 26
Dependent Claim
48 words
The valve as defined in claim 23, wherein: (a) a plurality of longitudinally spaced radially extending flanges extend around said sleeve means for isolating said pilot inlet from said pilot outlet; and, (b) each of said flanges includes a means for seating one of said resilient seal means.
Claim 27
Dependent Claim
42 words
The valve as defined in claim 24, wherein: (a) a plurality of spaced annular flow channels disposed about said sleeve means and extend between said flanges and adapted for connecting said pilot inlet and said pilot outlet with said sleeve means aperture.
Claim 28
Dependent Claim
51 words
The valve as defined in claim 25, wherein: (a) a plurality of orifices generally radially disposed in said sleeve means and at least one of said orifices is associated with each of said flow channels for permitting connection of said pilot inlet with said pilot outlet through said sleeve means aperture.
Claim 29
Dependent Claim
32 words
The valve as defined in claim 17, wherein: (a) securing means associated with the end of said sleeve means aperture adjacent said piston means and adapted for positively positioning said biasing means.
Claim 30
Dependent Claim
30 words
The valve as defined in claim 27, wherein: (a) said biasing means includes a spring disposed in said sleeve means aperture engagable with said securing means and said spool means.
Claim 31
Dependent Claim
70 words
The valve as defined in claim 17, wherein: (a) said second chamber is closed at an end thereof opposite said means by a low pressure closure cap; (b) an aperture is disposed in said low pressure closure cap coaxial with said second pressure inlet; and, (c) said piston means includes a portion thereof slidably disposed in said low pressure closure cap and adapted for being guided therein during displacement thereof.
Claim 32
Dependent Claim
49 words
The valve as defined in claim 29, wherein: (a) said piston means includes a piston having a shaft portion thereof disposed in said low pressure closure cap aperture; and, (b) said shaft has a length insufficient to cause said shaft to extend outwardly beyond said low pressure closure cap.
Claim 33
Dependent Claim
71 words
The valve as defined in claim 17, wherein: (a) said spool means includes at least two flanges having a diameter generally corresponding to said sleeve aperture diameter and a shaft interconnects said flanges; (b) said shaft has a diameter less than said sleeve means aperture diameter for thereby providing an annular flow channel; and, (c) a shaft extension longitudinally extends from one of said flanges and is engagable with said cylinder.
Claim 34
Dependent Claim
24 words
The valve as defined in claim 31, wherein: (a) a cylindrical recess disposed in said cylinder and adapted for receiving said shaft extension therein.
Claim 35
Dependent Claim
32 words
The valve as defined in claim 17, wherein: (a) said spool means and said cylinder each includes an aligned coaxial aperture adapted for being interconnected to thereby permit venting of said chambers.
Claim 36
Dependent Claim
17 words
The valve as defined in claim 17, wherein: (a) a drain port communicates with said second chamber.
Claim 37
Dependent Claim
20 words
The valve as defined in claim 17, wherein: (a) said first chamber has a diameter exceeding said second chamber diameter.
References Cited (Backward Citations)
US3716074A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-25 | 1989-05-27 | 1989-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-25 | 1993-05-27 | 1993-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-25 | 1997-05-27 | 1997-11-26 | $7700.00 | Window Closed / Lapsed |