US3663071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure-balanced piston and the like
Assignee: W A Kates Co
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Filing: 1971-04-23
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Granted: 1972-05-16
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Expires: 1991-04-23
Abstract
Abstract A pressure-balanced system wherein a cylindrical member such as a piston, a shaft, or the like, is movably received in a cylinder bore. Means are provided for balancing the cylindrical member so as to reduce friction between the cylindrical member and the wall of the cylinder bore as may result from a flow of fluid under pressure from an adjacent high-pressure space to an adjacent lowpressure space through the cylinder bore. The balancing means illustratively comprises an annular groove opening to the clearance space between the cylindrical member and the wall of the cylinder bore. In one form, the annular groove is disposed in the cylinder. In another form, the annular groove is disposed in the wall of the cylinder bore. The balancing means may be provided at the end of the clearance space adjacent the highpressure space, the low-pressure space, or both as desired. Means are provided for causing direct communication between the annular groove and the adjacent pressure space. The communication means illustratively comprises passages in the member in which the annular groove is provided. The illustrated passages comprise bores or laterally opening grooves.
Inventors
- 👤 Willard A Kates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:13
CPC Classifications
F; F16; F16C; F16C29/00; F16C29/02; F16J; F16J1/00; F16J1/09
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
205 words
In an apparatus having a cylindrical member movably received in an outer member bore having a first end opening to a highpressure space and a second end opening to a low-pressure space, said cylindrical member having a transverse section smaller than that of said outer member bore to define a clearance space between said cylindrical and outer members, structure for effectively minimizing friction of the cylindrical member against the outer member bore wall as a result of fluid flow through said clearance space from said high-pressure space to said lowpressure space, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said cylindrical member spaced adjacent a portion of said cylindrical member close to one of said pressure spaces; and four radial passages spaced apart 90* at said recess and having a preselected small diameter for providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said cylindrical member in said bore to minimize frictional drag on the cylindrical member.
Claim 2
Dependent Claim
205 words
In an apparatus having a cylindrical member movably received in an outer member bore having a first end opening to a highpressure space and a second end opening to a low-pressure space, said cylindrical member having a transverse section smaller than that of said outer member bore to define a clearance space between said cylindrical and outer members, structure for effectively minimizing friction of the cylindrical member against the outer member bore wall as a result of fluid flow through said clearance space from said high-pressure space to said lowpressure space, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said cylindrical member spaced adjacent a portion of said cylindrical member close to one of said pressure spaces; and four radial passages spaced apart 90* at said recess and having a preselected small diameter for providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said cylindrical member in said bore to minimize frictional drag on the cylindrical member.
Claim 3
Dependent Claim
12 words
The structure of claim 1 wherein said cylindrical member comprises a piston.
Claim 4
Dependent Claim
12 words
The structure of claim 1 wherein said cylindrical member comprises a shaft.
Claim 5
Dependent Claim
15 words
The structure of claim 1 wherein said annular recess is provided in said cylindrical member.
Claim 6
Dependent Claim
15 words
The structure of claim 1 wherein said annular recess is provided in said outer member.
Claim 7
Dependent Claim
24 words
The structure of claim 1 wherein said annular recess is provided adjacent the portion of the cylindrical member closest to said high pressure space.
Claim 8
Dependent Claim
56 words
The structure of claim 1 wherein said annular recess is provided adjacent the portion of the cylindrical member closest to said high-pressure space and said communication means comprises a first flow passage means opening axially to said high-pressure space, and second flow passage means extending transaxially between said first flow passage means and said annular recess.
Claim 9
Dependent Claim
22 words
The structure of claim 1 wherein said communication means comprises flow passage means extending parallel to the axis of said cylindrical member.
Claim 10
Dependent Claim
23 words
The structure of claim 1 wherein said communication means comprises grooves in said one of said members opening laterally to said clearance space.
Claim 11
Dependent Claim
24 words
The structure of claim 1 wherein said communication means comprises a bore in said one of said members spaced transaxially from said clearance space.
Claim 12
Dependent Claim
193 words
In an apparatus having a piston member movably received in a cylinder member having a bore defining a first end opening to a high-pressure space and a second end opening to a low-pressure space, said piston member having a transverse section smaLler than that of said cylinder member bore to define a clearance space between said piston and cylinder members, structure for effectively minimizing friction of the piston member against the cylinder member bore wall, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said piston member spaced adjacent a portion of said piston member close to one of said pressure spaces, the wall of said one member between said recess and the distal end being substantially right circularly cylindrical; and passage means providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said piston member in said bore to minimize frictional drag on the piston member.
Claim 13
Dependent Claim
193 words
In an apparatus having a piston member movably received in a cylinder member having a bore defining a first end opening to a high-pressure space and a second end opening to a low-pressure space, said piston member having a transverse section smaLler than that of said cylinder member bore to define a clearance space between said piston and cylinder members, structure for effectively minimizing friction of the piston member against the cylinder member bore wall, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said piston member spaced adjacent a portion of said piston member close to one of said pressure spaces, the wall of said one member between said recess and the distal end being substantially right circularly cylindrical; and passage means providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said piston member in said bore to minimize frictional drag on the piston member.
Claim 14
Dependent Claim
217 words
In an apparatus having a cylindrical member movably received in an outer member bore having a first end opening to a high-pressure space and a second end opening to a low-pressure space, said cylindrical member having a transverse section smaller than that of said outer member bore to define a clearance space between said cylindrical and outer members, structure for effectively minimizing friction of the cylindrical member against the outer member bore wall as a result of fluid flow through said clearance space from said high-pressure space to said low-pressure space, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said cylindrical member spaced adjacent a portion of said cylindrical member close to one of said pressure spaces; and grooves in one of said members opening radially to said clearance space and extending between said annular recess and the distal end of the cylindrical member defining means providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said cylindrical member in said bore to minimize frictional drag on the cylindrical member.
Claim 15
Dependent Claim
217 words
In an apparatus having a cylindrical member movably received in an outer member bore having a first end opening to a high-pressure space and a second end opening to a low-pressure space, said cylindrical member having a transverse section smaller than that of said outer member bore to define a clearance space between said cylindrical and outer members, structure for effectively minimizing friction of the cylindrical member against the outer member bore wall as a result of fluid flow through said clearance space from said high-pressure space to said low-pressure space, said structure comprising: means on at least one of said members defining an annular recess in one of said members opening to said clearance space at a portion of said cylindrical member spaced adjacent a portion of said cylindrical member close to one of said pressure spaces; and grooves in one of said members opening radially to said clearance space and extending between said annular recess and the distal end of the cylindrical member defining means providing limited communication between said recess and said one pressure space for causing a controlled reduced pressure differential between said one space and the pressure of the fluid in said annular recess for effecting centering of said cylindrical member in said bore to minimize frictional drag on the cylindrical member.
Claim 16
Dependent Claim
13 words
The structure of claim 12 wherein said recess is in said cylindrical member.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |