US3578787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system
Assignee: NORTHWEST ENGINEERING Co
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Filing: 1968-11-12
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Granted: 1971-05-18
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Expires: 1988-11-12
Abstract
Abstract A control system for a convertible pullshovel-crane wherein a plurality of hydraulic cylinders and/or hydraulic motors are actuated by a combination of air cylinders and hydraulic valves. In one embodiment, booster means for some of the hydraulic cylinders are provided with interlocks to prevent booster operation under certain conditions. In another embodiment, a plurality of hoist drums are controlled by the hydraulic motors, with the drums having both friction brakes as well as friction clutches to provide flexibility of cable control. Various bypasses and interconnections in the pneumatic circuit permit varying or fixing certain drum speeds.
Inventors
- 👤 Alan E Brickett
- 👤 Evertt R Windahl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:02
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/20; E02F9/22; E02F9/2203; E02F9/2016
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
180 words
In a device of the class described having a boom, means for raising and lowering the boom, a front and a rear shaft with corresponding front and rear drums mounted thereon with said drums having cables wound thereon which extend over the boom for performing desired functions, and having hydraulic motor means connected for driving both said shafts in either direction; a control system comprising, in combination: a. hydraulic drum valve means connected to said motor means to operate the latter, a double-acting cylinder having its piston connected to said drum valve means to move the latter between its various operating positions, pneumatic circuit means including a manually operated pneumatic metering valve connected between a source of air and both sides of said double-acting cylinder to operate said drum valve means, said metering valve controlling the speed of said motor means from a maximum to a lesser speed, c. and lockup means prOvided in said circuit to bypass said metering valve to provide maximum speed of said motor means when said metering valve is set for less than maximum speed.
Claim 2
Dependent Claim
180 words
In a device of the class described having a boom, means for raising and lowering the boom, a front and a rear shaft with corresponding front and rear drums mounted thereon with said drums having cables wound thereon which extend over the boom for performing desired functions, and having hydraulic motor means connected for driving both said shafts in either direction; a control system comprising, in combination: a. hydraulic drum valve means connected to said motor means to operate the latter, a double-acting cylinder having its piston connected to said drum valve means to move the latter between its various operating positions, pneumatic circuit means including a manually operated pneumatic metering valve connected between a source of air and both sides of said double-acting cylinder to operate said drum valve means, said metering valve controlling the speed of said motor means from a maximum to a lesser speed, c. and lockup means prOvided in said circuit to bypass said metering valve to provide maximum speed of said motor means when said metering valve is set for less than maximum speed.
Claim 3
Dependent Claim
36 words
The control system of claim 14 wherein said lockup means comprises an on-off type valve connected between said source of air and one side of the connection between said metering valve and said drum valve means.
Claim 4
Dependent Claim
61 words
a second manually operable pneumatic valve connected between said air supply and said right clutch to actuate the latter, said second valve having a ''''right'''' and a ''''neutral'''' position, c. and valve control means connecting said first and second valves for permitting clutching of both said left and right clutches simultaneously while said first valve is in ''''rear'''' or ''''neutral'''' position.
Claim 5
Dependent Claim
61 words
a second manually operable pneumatic valve connected between said air supply and said right clutch to actuate the latter, said second valve having a ''''right'''' and a ''''neutral'''' position, c. and valve control means connecting said first and second valves for permitting clutching of both said left and right clutches simultaneously while said first valve is in ''''rear'''' or ''''neutral'''' position.
Claim 6
Dependent Claim
20 words
the connection from said second valve and said right clutch, b. and a manually operable on-off valve in said line.
Claim 7
Dependent Claim
20 words
the connection from said second valve and said right clutch, b. and a manually operable on-off valve in said line.
Claim 8
Dependent Claim
118 words
In a device of the class described having a boom, means for raising and lowering the boom, a front and a rear shaft with hydraulic motor means connected for driving said shafts in either direction, a left and a right drum mounted on said front shaft, a rear drum mounted on said rear shaft, said drums having cables wound thereon which extend over the boom for performing desired functions; a control system comprising, in combination: a. a left, right and rear friction clutch on each said respective drum for clutching and declutching each drum to its respective shaft, b. manually operably clutch control means for operating each said clutch independently of the other, said clutch control means comprising:
Claim 9
Dependent Claim
118 words
In a device of the class described having a boom, means for raising and lowering the boom, a front and a rear shaft with hydraulic motor means connected for driving said shafts in either direction, a left and a right drum mounted on said front shaft, a rear drum mounted on said rear shaft, said drums having cables wound thereon which extend over the boom for performing desired functions; a control system comprising, in combination: a. a left, right and rear friction clutch on each said respective drum for clutching and declutching each drum to its respective shaft, b. manually operably clutch control means for operating each said clutch independently of the other, said clutch control means comprising:
Claim 10
Dependent Claim
17 words
The control system of claim 3 wherein said valve control means comprises: a. a pneumatic line between:
Claim 11
Dependent Claim
42 words
The control system of claim 4 which includes adjustable drag regulating means in said pneumatic line to vary the pressure of air in the line so that the cable pull of said left drum relative to said right drum may be varied.
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |