US3866880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve assembly having a pressure responsive detent mechanism
Assignee: Caterpillar Inc
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Filing: 1973-10-09
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Granted: 1975-02-18
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Expires: 1993-10-09
Abstract
Abstract A fluid control spool valve for directing operating fluid from a high pressure source for moving a fluid-operated motor in forward or in reverse is disclosed. The valve automatically moves to neutral position upon loss of fluid pressure by the operation of a centering spring that is adjusted to move the spool to neutral position when a pressure responsive detent becomes nonfunctional. A second spring maintains the detent operative when the operating fluid is at high pressure but makes the detent inoperative when the operating fluid is at low pressure whereupon the spool is automatically moved to a neutral position.
Inventors
- 👤 Lawrence F Schexnayder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:10
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/4061; F16K; F16K11/00; F16K11/02; F16K11/06; F16K11/065; F16K11/07; F16K11/0704; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86485
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
216 words
A hydraulic valve Assembly comprising: a valve body having a cylindrical bore and fluid inlet and outlet openings communicating with said bore; a spool reciprocably disposed in said bore and movable to at least a first operating position to effect communication between said inlet and outlet openings, and to a neutral position to block said communication; centering spring means for biasing said spool to said neutral position; and pressure responsive detent means disposed in said valve body and responsive to a predetermined operating fluid pressure to hold said spool in said operating position against the force of said centering spring, and operative in response to a drop in said fluid pressure below said predetermined pressure to release said spool for movement by said centering spring to neutral position, said detent means comprising a plurality of annular grooves extending around the outer diameter of said spool, a plurality of balls mounted in said valve body surrounding said spool for engagement with said grooves, reciprocal annular camming means extending around said spool externally thereof for engaging and biasing said balls into said grooves, and piston means mounted in said housing and responsive to fluid pressure for biasing said annular camming means into camming engagement with said balls, including resilient means connecting said piston to said annular camming means.
Claim 2
Dependent Claim
216 words
A hydraulic valve Assembly comprising: a valve body having a cylindrical bore and fluid inlet and outlet openings communicating with said bore; a spool reciprocably disposed in said bore and movable to at least a first operating position to effect communication between said inlet and outlet openings, and to a neutral position to block said communication; centering spring means for biasing said spool to said neutral position; and pressure responsive detent means disposed in said valve body and responsive to a predetermined operating fluid pressure to hold said spool in said operating position against the force of said centering spring, and operative in response to a drop in said fluid pressure below said predetermined pressure to release said spool for movement by said centering spring to neutral position, said detent means comprising a plurality of annular grooves extending around the outer diameter of said spool, a plurality of balls mounted in said valve body surrounding said spool for engagement with said grooves, reciprocal annular camming means extending around said spool externally thereof for engaging and biasing said balls into said grooves, and piston means mounted in said housing and responsive to fluid pressure for biasing said annular camming means into camming engagement with said balls, including resilient means connecting said piston to said annular camming means.
Claim 3
Dependent Claim
19 words
The valve assembly of claim 1 wherein said piston means is mounted externally of said spool and axially thereof.
Claim 4
Dependent Claim
61 words
The valve assembly of claim 2 comprising a fixed ring member fixed in said bore concentric with said spool adjacent said annular grooves; said annular camming means comprises a cam ring member having a substantially conical face on one side thereof; and said balls are confined between said fixed ring member and said substantially conical face of said cam ring member.
Claim 5
Dependent Claim
14 words
The valve assemby of claim 3 wherein said resilient means comprises a compression spring.
Claim 6
Dependent Claim
203 words
A hydraulic valve assembly comprising: a valve body having a cylindrical bore and fluid inlet and outlet openings communicating with said bore; a spool reciprocably disposed in said bore and movable to at least a first operating position to effect communication between said inlet and outlet openings, and to a neutral position to block said communication; centering spring means for biasing said spool to said neutral position; pressure responsive detent means disposed in said valve body, responsive to a predetermined operating fluid pressure to hold said spool in said operating position against the force of said centering spring, and operative in response to a drop in said fluid pressure below said predetermined pressure to release said spool for movement by said centering spring to neutral position, said detent means comprising a plurality of annular grooves extending around said spool, a plurality of balls mounted in said valve body surrounding said spool for engagement with said grooves, and camming means including an annular cam member reciprocably mounted in said bore and having an inclined surface engaging and biasing said balls into said grooves, a fluid pressure responsive piston mounted in said valve body, and spring means connecting said piston to said annular cam member.
Claim 7
Dependent Claim
203 words
A hydraulic valve assembly comprising: a valve body having a cylindrical bore and fluid inlet and outlet openings communicating with said bore; a spool reciprocably disposed in said bore and movable to at least a first operating position to effect communication between said inlet and outlet openings, and to a neutral position to block said communication; centering spring means for biasing said spool to said neutral position; pressure responsive detent means disposed in said valve body, responsive to a predetermined operating fluid pressure to hold said spool in said operating position against the force of said centering spring, and operative in response to a drop in said fluid pressure below said predetermined pressure to release said spool for movement by said centering spring to neutral position, said detent means comprising a plurality of annular grooves extending around said spool, a plurality of balls mounted in said valve body surrounding said spool for engagement with said grooves, and camming means including an annular cam member reciprocably mounted in said bore and having an inclined surface engaging and biasing said balls into said grooves, a fluid pressure responsive piston mounted in said valve body, and spring means connecting said piston to said annular cam member.
Claim 8
Dependent Claim
28 words
The valve assembly of claim 5 comprising an annular shoulder disposed in said bore, and said balls confined between said shoulder, said spool and said annular cam member.
Claim 9
Dependent Claim
16 words
The valve assembly of claim 5 comprising stop means for limiting the movement of said piston.
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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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |