US3847059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual control valve assembly
Assignee: Caterpillar Inc
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Filing: 1973-09-04
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Granted: 1974-11-12
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Expires: 1993-09-04
Abstract
Abstract A simplified dual control valve assembly for operating a pair of hydraulic jacks in unison, each control valve being operable to selectively communicate operating pressure to one end of each jack, separate pumps providing fluid under pressure to each of the control valves through inlet conduits which are in communication with each other by means of a restrictive orifice. The restrictive orifice assures balanced fluid pressures available to both of the control valves while pressure equilizing lines effectively communicate respective portions of the hydraulic jacks to assure their operation in unison.
Inventors
- 👤 H Beck
- 👤 W Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:55
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/16; F15B11/22
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
A hydraulic control circuit for operating a pair of doubleacting hydraulic jacks in unison, each of the jacks having a rod end and a head end, the hydraulic control circuit comprising two similar control valves responsive to a common actuating means, each control valve including a fluid inlet port, two service chambers and drain means, a spool being movable within each control valve by the common actuating means for selectively communicating the servicE chambers with the inlet port and drain means, each control valve having its service chambers in communication with one end of each of the two hydraulic jacks, two similar sources of fluid under pressure, inlet conduit means respectively communicating the two sources with the fluid inlet ports for the two control valves, and means defining a restrictive orifice arranged in communication between the two inlet conduits.
Claim 2
Dependent Claim
139 words
A hydraulic control circuit for operating a pair of doubleacting hydraulic jacks in unison, each of the jacks having a rod end and a head end, the hydraulic control circuit comprising two similar control valves responsive to a common actuating means, each control valve including a fluid inlet port, two service chambers and drain means, a spool being movable within each control valve by the common actuating means for selectively communicating the servicE chambers with the inlet port and drain means, each control valve having its service chambers in communication with one end of each of the two hydraulic jacks, two similar sources of fluid under pressure, inlet conduit means respectively communicating the two sources with the fluid inlet ports for the two control valves, and means defining a restrictive orifice arranged in communication between the two inlet conduits.
Claim 3
Dependent Claim
29 words
The control circuit of claim 1 wherein the two control valves are pilot operated and the common actuating means is a pilot control circuit including a pilot control valve.
Claim 4
Dependent Claim
56 words
The hydraulic control circuit of claim 2 wherein the pilot actuated control valves are arranged in parallel relation with each other, the pilot actuated spools being simultaneously operable in opposition to each other, the service chambers on adjacent ends of the two control valves being in respective communication with opposite ends of the same hydraulic jack.
Claim 5
Dependent Claim
31 words
The control circuit of claim 3 further comprising pressure equalizing conduits respectively communicating with service chambers in the two control valves for balancing operating pressure communicated to the two hydraulic jacks.
Claim 6
Dependent Claim
79 words
The hydraulic control circuit of claim 4 further comprising a common drain manifold arranged between the two control valves, the common drain manifold being in communication with the drain means of each control valve, each control valve having a neutral position wherein the service chambers are blocked by the spool, the spool in each control valve including means for communicating the respective fluid inlet port with the common drain manifold when the control valve is in its neutral condition.
Claim 7
Dependent Claim
67 words
The hydraulic control circuit of claim 5 wherein the two hydraulic jacks are mounted in parallel relation for extending and retracting operation, the two control valves being arranged in parallel relation with each other and in transverse relation with the hydraulic jacks, a pair of access conduits communicating the service chambers of each valve with the respective hydraulic jacks, each access conduit including a U-shaped conduit portion.
Claim 8
Dependent Claim
34 words
The hydraulic control circuit of claim 6 wherein the U-shaped conduit portion for one of the control valves is arranged in cross-over relation to permit simultaneous retraction and extension of the two hydraulic jacks.
Claim 9
Dependent Claim
34 words
The control circuit of claim 1 further comprising pressure equalizing conduits each in respective communication with service chambers in the two control valves for balancing operating pressures simultaneously communicated to the two hydraulic jacks.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |