US3659672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system
Assignee: CHARLES EQUIPMENT CO
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Filing: 1971-01-11
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Granted: 1972-05-02
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Expires: 1991-01-11
Abstract
Abstract A control system using a motive source and connected hydrostatic transmission to drive a load at a speed determined by the volume of fluid flowing in the transmission. A comparator and actuator change the volume of fluid flow in proportion to the deviation between a feedback signal and a control signal. The feedback signal is generated by a sensor responsive to the output of the transmission. The control signal has a value dependent upon the type of load connected to the transmission.
Inventors
- 👤 Charles J Jacobus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:31
CPC Classifications
B; B60; B60K; B60K17/00; B60K17/04; B60K17/10; F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/47; F25; F25D; F25D29/00; F25D29/003
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
245 words
In a system having an AC motor with a motor shaft driven at a speed directly proportional to a frequency input to the AC motor, a control comprising: a source of rotating motive power; hydrostatic transmission means having an input coupling connected to said motive source, an output coupling, and adjustment means for selecting different speeds of rotation of said output coupling for a given speed of rotation of said input coupling; an AC generator having an AC output connected to the frequency input of said AC motor, said AC generator having an input shaft coupled to said output coupling to cause the AC output to have a frequency dependent upon the speed of rotation of the input shaft and connected output coupling; feedback means coupled to said AC output for generating a feedback signal having a frequency directly corresponding to the AC output frequency of said AC generator; control means including a speed sensing means located adjacent said motor shaft for generating a control signal having a frequency proportional to the speed of rotation of said motor shaft; frequency comparator means for comparing the frequency of said feedback signal with the frequency of said control signal to produce a command proportional to the frequency deviation between said signals; and actuator means responsive to said command for varying said adjustment means in proportion to the frequency deviation, thereby limiting the slip of said motor shaft due to the effect of an exTernal load coupled thereto.
Claim 2
Dependent Claim
245 words
In a system having an AC motor with a motor shaft driven at a speed directly proportional to a frequency input to the AC motor, a control comprising: a source of rotating motive power; hydrostatic transmission means having an input coupling connected to said motive source, an output coupling, and adjustment means for selecting different speeds of rotation of said output coupling for a given speed of rotation of said input coupling; an AC generator having an AC output connected to the frequency input of said AC motor, said AC generator having an input shaft coupled to said output coupling to cause the AC output to have a frequency dependent upon the speed of rotation of the input shaft and connected output coupling; feedback means coupled to said AC output for generating a feedback signal having a frequency directly corresponding to the AC output frequency of said AC generator; control means including a speed sensing means located adjacent said motor shaft for generating a control signal having a frequency proportional to the speed of rotation of said motor shaft; frequency comparator means for comparing the frequency of said feedback signal with the frequency of said control signal to produce a command proportional to the frequency deviation between said signals; and actuator means responsive to said command for varying said adjustment means in proportion to the frequency deviation, thereby limiting the slip of said motor shaft due to the effect of an exTernal load coupled thereto.
Claim 3
Dependent Claim
89 words
The control of claim 1 for controlling a vehicle, wherein the external load coupled to the motor shaft comprises a wheel for propelling said vehicle at a speed related to the speed of rotation of the wheel, said motive source comprising an engine having a throttle for controlling the speed of rotation of an engine shaft, means connecting said input coupling of said hydrostatic transmission means to said engine shaft, and linkage means for varying the position of said throttle to control the speed of movement of said vehicle.
Claim 4
Dependent Claim
58 words
The control of claim 2 including bias means for generating a bias voltage varying in proportion to the position of an input arm, means coupling said linkage means to said input arm, and said comparator means being responsive to said bias voltage to scale the value of said command in proportion to the magnitude of said bias voltage.
References Cited (Backward Citations)
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GB1104354A
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US3477013A
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US3565202A
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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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |