US3722723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tilt cylinder anticavitation circuit
Assignee: AC MATERIAL HANDLING Corp 777 MANOR PARK DRIVE COLUMBUS OHIO 43228 A CORP OHIO
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Filing: 1972-01-20
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Granted: 1973-03-27
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Expires: 1992-01-20
Abstract
Abstract Cavitation in the tilt cylinder circuit for a lift truck is prevented by cross connecting one of the tilt cylinder supply lines with the return-to-reservoir line of another circuit in the lift truck hydraulic system. A cone-way check valve is incorporated in the cross connecting passage to prevent flow from the tilt cylinder circuit to the second circuit.
Inventors
- 👤 D Matthews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:34
CPC Classifications
B; B66; B66F; B66F9/00; B66F9/06; B66F9/075; B66F9/20; B66F9/22
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
In a lift truck having a tiltable mast with elevatable load carrying carriage, the combination comprising: a hydraulic tilt cylinder; a hydraulic circuit for controlling said tilt cylinder including a tilt control valve, tilt cylinder supply conduits interconnecting said tilt control valve and said tilt cylinder and supply and exhaust conduits connected to said tilt control valve; an auxiliary hydraulic cylinder; a hydraulic circuit for controlling said auxiliary cylinder including control valve means, input and exhaust passages connected to said control valve means, and supply passages interconnecting said auxiliary cylinder and said control valve means; fluid supply means operable to supply fluid under pressure to said input conduit and said input passage; and an anticavitation circuit including a cross passage interconnecting one of said tilt cylinder supply conduits and said exhaust passage including one-way flow control means in said cross passage permitting flow to fluid therein only from said exhaust passage to said one supply conduit.
Claim 2
Dependent Claim
156 words
In a lift truck having a tiltable mast with elevatable load carrying carriage, the combination comprising: a hydraulic tilt cylinder; a hydraulic circuit for controlling said tilt cylinder including a tilt control valve, tilt cylinder supply conduits interconnecting said tilt control valve and said tilt cylinder and supply and exhaust conduits connected to said tilt control valve; an auxiliary hydraulic cylinder; a hydraulic circuit for controlling said auxiliary cylinder including control valve means, input and exhaust passages connected to said control valve means, and supply passages interconnecting said auxiliary cylinder and said control valve means; fluid supply means operable to supply fluid under pressure to said input conduit and said input passage; and an anticavitation circuit including a cross passage interconnecting one of said tilt cylinder supply conduits and said exhaust passage including one-way flow control means in said cross passage permitting flow to fluid therein only from said exhaust passage to said one supply conduit.
Claim 3
Dependent Claim
55 words
The combination of claim 1 wherein said fluid supply means includes a pump and a flow divider valve connected to the output side of said pump and connected in fluid delivery relation to said input conduit and said input passage, said flow divider valve effecting priority of flow from said pump to said input passage.
Claim 4
Dependent Claim
16 words
The combination of claim 2 wherein said control valve means is an open center control valve.
Claim 5
Dependent Claim
18 words
The combination of claim 3 wherein said auxiliary hydraulic cylinder is a steering cylinder for said lift truck.
Claim 6
Dependent Claim
20 words
The combination of claim 1 wherein said fluid supply means effects a priority of fluid supply to said input passage.
Claim 7
Dependent Claim
18 words
The combination of claim 5 wherein said auxiliary hydraulic cylinder is a stEering cylinder for said lift truck.
Claim 8
Dependent Claim
17 words
The combination of claim 6 wherein said control valve means is an open center steering control valve.
Claim 9
Dependent Claim
15 words
The combination of claim 7 wherein said one-way flow control means is a check valve.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |