US3729910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulically operated offset cutter
Assignee: HARDEE MANUFACTURING COMPANY Inc
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Filing: 1971-11-19
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Granted: 1973-05-01
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Expires: 1991-11-19
Abstract
Abstract A hydraulically operated offset cutter having a hydraulic circuit driving a cylinder for raising, lowering or stabilizing the position of a hydraulically driven cutter driven from the same pump as said cylinder piston. The cylinder circuit has a uniquely provided control valve to accomplish the selective operations of raising, lowering or stabilizing the hydraulically driven cutter. The control valve contains a bypass line containing one or more pressure-restricting orifices for passing oil to the motor under conditions when the control valve provides useful flow of oil to a piston for raising or lowering the offset cutter, enabling the motor to continue operating. Thus a back pressure builds up behind the orifices and the oil is directed by the control valve to the cylinder piston causing it to operate as desired.
Inventors
- 👤 E Hardee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:34
CPC Classifications
A; A01; A01D; A01D34/00; A01D34/01; A01D34/02; A01D34/24; A01D34/246; A01D34/835; A01D34/86
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
182 words
An improved hydraulic circuit for a pivotally mounted offset cutter apparatus comprising an offset rotary cutter; a hydraulic drive pump and a hydraulic motor in a hydraulic circuit with the pump for operating said offset cutter; a control valve in said hydraulic circuit relating with said pump and said motor, and a hydraulic piston and cylinder in circuit relation with said control valve for said piston upon actuation by said control valve to hold, raise and lower said offset cutter, and said control valve including a valve slider for said control valve for selectively providing (1) a normal flow path through the control valve to drive the motor and blocking flow in the circuit of the hydraulic cylinder, (2) a ''''raise'''' flow path through the control valve to actuate the piston to raise the offset cutter, and (3) a ''''lower'''' flow path through the control valve to actuate the piston to lower the offset cutter, said control valve having a bypass line including at least one pressure-restricting orifice allowing flow to the motor at a reduced rate in operating said offset cutter.
Claim 2
Dependent Claim
182 words
An improved hydraulic circuit for a pivotally mounted offset cutter apparatus comprising an offset rotary cutter; a hydraulic drive pump and a hydraulic motor in a hydraulic circuit with the pump for operating said offset cutter; a control valve in said hydraulic circuit relating with said pump and said motor, and a hydraulic piston and cylinder in circuit relation with said control valve for said piston upon actuation by said control valve to hold, raise and lower said offset cutter, and said control valve including a valve slider for said control valve for selectively providing (1) a normal flow path through the control valve to drive the motor and blocking flow in the circuit of the hydraulic cylinder, (2) a ''''raise'''' flow path through the control valve to actuate the piston to raise the offset cutter, and (3) a ''''lower'''' flow path through the control valve to actuate the piston to lower the offset cutter, said control valve having a bypass line including at least one pressure-restricting orifice allowing flow to the motor at a reduced rate in operating said offset cutter.
Claim 3
Dependent Claim
34 words
The invention of claim 1 wherein said valve slider includes said bypass line and including a restrictive orifice path essentially operative only when the ''''raise'''' flow path or the ''''lower'''' flow path is operative.
Claim 4
Dependent Claim
17 words
The invention according to claim 2 wherein said control slider is provided with a control valve lever.
Claim 5
Dependent Claim
33 words
The invention according to claim 2 wherein said circuit includes an oil reservoir to collect oil flow from the low pressure side of said motor and a return line from said control valve.
Claim 6
Dependent Claim
18 words
The invention according to claim 2 wherein said offset cutter is significantly counterbalanced by oil in said reservoir.
Claim 7
Dependent Claim
26 words
The invention according to claim 2 wherein said offset cutter is supported by manually adjustable means provided to selectively re-position the orientation of the offset cutter.
Claim 8
Dependent Claim
22 words
The invention according to claim 2 wherein filter means is provided in the oil return line from the motor to the reservoir.
Claim 9
Dependent Claim
18 words
The invention according to claim 2 wherein valve means is interposed between the reservoir and the drive pump.
Claim 10
Dependent Claim
41 words
The invention according to claim 1 wherein said bypass line is external of the control valve and where said bypass line includes a restrictive orifice path essentially operative only when the ''''raise'''' flow path or the ''''lower'''' flow path is operative.
Claim 11
Dependent Claim
29 words
The invention according to claim 1, wherein the bypass line is interiorly disposed within the control valve by said bypass being structured as a recess on said valve slider.
References Cited (Backward Citations)
US2976663A
Cited
US2953164A
Cited
US3087296A
Cited
US3319407A
Cited
US3548570A
Cited
US3559385A
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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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |