Patent US144918A successfully refreshed from Google Patents.
Patent US4500968A successfully refreshed from Google Patents.
Patent US4033236A successfully refreshed from Google Patents.
US4033236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
All hydraulic motor grader circuitry
Assignee: Caterpillar Inc
•
Filing: 1974-02-04
•
Granted: 1977-07-05
•
Expires: 1994-02-04
Abstract
Abstract A closed center control valve for double acting motors having an inlet passage and a pair of control passages is provided with pre-sized restrictions in the control passages to control the flow rate to the motor so that a pre-selected velocity of movement of the motor is achieved.
Inventors
- 👤 Howard L. Johnson
- 👤 John A. Junck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:48
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/0416; F15B13/0417; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87217; Y10T137/87225
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
214 words
The combination of a control valve and a double acting hydraulic motor including a housing having a cylindrical chamber divided by a piston and rod assembly into a head end and a rod end having different fluid volumes, said valve comprising: a valve body having an inlet passage and a pair of motor control passages one of said motor control passages connected to the head end of said motor and the other of said motor control passages connected to the rod end of said double acting motor; a cylindrical bore in said housing communicating with said inlet passage and said motor control passage; a valve spool reciprocably mounted in said bore and movable from a neutral position for controlling the flow of fluid between said inlet passage and said motor control passages; and, restricting means in the one of said control passages connected to the rod end of said motor for fixing the size of said one passage in relation to the size of said other passage to the same proportion that the volume of the rod end of said motor bears to the head end of said motor proportioning the flow of fluid to said motor through said control passages for thereby providing the same velocity movement of said motor in either direction.
Claim 2
Dependent Claim
214 words
The combination of a control valve and a double acting hydraulic motor including a housing having a cylindrical chamber divided by a piston and rod assembly into a head end and a rod end having different fluid volumes, said valve comprising: a valve body having an inlet passage and a pair of motor control passages one of said motor control passages connected to the head end of said motor and the other of said motor control passages connected to the rod end of said double acting motor; a cylindrical bore in said housing communicating with said inlet passage and said motor control passage; a valve spool reciprocably mounted in said bore and movable from a neutral position for controlling the flow of fluid between said inlet passage and said motor control passages; and, restricting means in the one of said control passages connected to the rod end of said motor for fixing the size of said one passage in relation to the size of said other passage to the same proportion that the volume of the rod end of said motor bears to the head end of said motor proportioning the flow of fluid to said motor through said control passages for thereby providing the same velocity movement of said motor in either direction.
Claim 3
Dependent Claim
26 words
The invention of claim 1 wherein said valve element is a spool having tapered lands defining conical sections extending outward from the center of said spool.
Claim 4
Dependent Claim
39 words
The invention of claim 1 comprising means including a spring and sleeve embracing one end of said spool and threaded plug means mounted in one end of said bore and engaging said sleeve for adjustably centering said valve element.
Claim 5
Dependent Claim
49 words
The invention of claim 1 comprising an actuating lever pivotally mounted in said housing and operatively connected to operate said valve element; said pivotal mounting comprising a spherical section carried by said lever and having means defining a fulcrum mounted in said housing and adjustably embracing said spherical section.
Claim 6
Dependent Claim
18 words
The invention of claim 1 wherein said restricting means comprises an orifice in each of said control passages.
Claim 7
Dependent Claim
35 words
The valve of claim 1 comprising pressure responsive valve means disposed in said inlet passage prior to intersection thereof with said slidable valve element for controlling the flow of inlet fluid to said valve element.
Claim 8
Dependent Claim
28 words
The valve of claim 6 wherein said pressure responsive valve means is responsive to pressure in a selected one of said control passages to control said fluid flow.
Claim 9
Dependent Claim
10 words
The invention of claim 5 wherein said orifices are removable.
Claim 10
Dependent Claim
19 words
The invention of claim 5 wherein said orifices are formed in removable inserts threadably attached in said control passages.
References Cited (Backward Citations)
US1964196A
Cited
FR786189A
Cited
US2157707A
Cited
US2240898A
Cited
US2857886A
Cited
US2710628A
Cited
US3099135A
Cited
US2974637A
Cited
US2995141A
Cited
US3106938A
Cited
US3198088A
Cited
US3186307A
Cited
US3379133A
Cited
US3685531A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-04 | 1981-01-03 | 1981-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-04 | 1985-01-03 | 1985-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-04 | 1989-01-03 | 1989-07-05 | $7700.00 | Window Closed / Lapsed |