Patent US3717213A successfully refreshed from Google Patents.
US3717213A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle drive system and control means therefor
Assignee: Enerpac Tool Group Corp
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Filing: 1970-07-17
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Granted: 1973-02-20
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Expires: 1990-07-17
Abstract
Abstract A hydraulic drive system for motor vehicles, particularly track vehicles, of the type having hydraulic motors for each of the tracks and pumps for each of said motors, with each pump being driven by a prime mover. The output of each pump is inversely proportional to the pressure of a fluid control signal fed back from the output line of the pumps through a pressure regulator which regulates the pressure of the control signal. A governorregulator communicates with the first-mentioned regulators and sets the lower limit of the pressure range of the control signal and thereby sets the upper limit on the speed of the vehicle because of the inverse relationship between the output of the pumps and the pressure of the control signals.
Inventors
- 👤 R Roe
- 👤 G Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:56
CPC Classifications
B; B60; B60K; B60K17/00; B60K17/04; B60K17/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
195 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, said first and second regulators being in communication with the output pressure of said pumps and variably communicating said output pressures back to said first and second pumps over said range of pressures as said control signals, said third regulator being in communication with the output pressure of said pumps and variably communicating a portion of said output pressure to said first and second regulators for assisting in the control of said first and second regulators and for setting a lower limit of said pressure range of said control signal irrespective of said actuators.
Claim 2
Dependent Claim
195 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, said first and second regulators being in communication with the output pressure of said pumps and variably communicating said output pressures back to said first and second pumps over said range of pressures as said control signals, said third regulator being in communication with the output pressure of said pumps and variably communicating a portion of said output pressure to said first and second regulators for assisting in the control of said first and second regulators and for setting a lower limit of said pressure range of said control signal irrespective of said actuators.
Claim 3
Dependent Claim
195 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, said first and second regulators being in communication with the output pressure of said pumps and variably communicating said output pressures back to said first and second pumps over said range of pressures as said control signals, said third regulator being in communication with the output pressure of said pumps and variably communicating a portion of said output pressure to said first and second regulators for assisting in the control of said first and second regulators and for setting a lower limit of said pressure range of said control signal irrespective of said actuators.
Claim 4
Dependent Claim
195 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, said first and second regulators being in communication with the output pressure of said pumps and variably communicating said output pressures back to said first and second pumps over said range of pressures as said control signals, said third regulator being in communication with the output pressure of said pumps and variably communicating a portion of said output pressure to said first and second regulators for assisting in the control of said first and second regulators and for setting a lower limit of said pressure range of said control signal irrespective of said actuators.
Claim 5
Dependent Claim
161 words
In a vehicle, a drive system comprising a hydraulic drive motor, a pump for driving said motor of the type having a variable output which is inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first pressure regulator means regulating the pressure of the control signal to said pump over a range of pressures, actuator means for controlling said pressure regulator means and thereby controlling the pressure of said control signal, second pressure regulator means communicating with said first regulator means, each of said regulators being in communication with the output pressure of said pump, said first regulator variably communicating said output pressure back to said pump as said control signal over said range of pressures, said second regulator means variably communicating said output pressure to said first regulator means to assist in the control thereof and selectively setting a lower limit of said pressure range regulated by said first regulator means irrespective of said actuator means.
Claim 6
Dependent Claim
161 words
In a vehicle, a drive system comprising a hydraulic drive motor, a pump for driving said motor of the type having a variable output which is inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first pressure regulator means regulating the pressure of the control signal to said pump over a range of pressures, actuator means for controlling said pressure regulator means and thereby controlling the pressure of said control signal, second pressure regulator means communicating with said first regulator means, each of said regulators being in communication with the output pressure of said pump, said first regulator variably communicating said output pressure back to said pump as said control signal over said range of pressures, said second regulator means variably communicating said output pressure to said first regulator means to assist in the control thereof and selectively setting a lower limit of said pressure range regulated by said first regulator means irrespective of said actuator means.
Claim 7
Dependent Claim
236 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, means communicating the output pressures of said pumps to each of said regulators, siad first and second regulators variably communicating the output pressure back to said first and second pumps as control signals, valve means in each of said regulators responsive to said output pressures, adjustable biasing means operated by said actuators acting on said valve means whereby the greater the biasing force the greater the pressure transmitted from the regulators as control signals, said third regulator variably communicating said output pressure to said first and second regulators whereby the force of the biasing means of the first and second regulators is augmented by the pressure transmitted from said third regulator thereby providing a minimum biasing force irrespective of said adjustable biasing means and setting a lower limit on the pressures transmitted as control signals.
Claim 8
Dependent Claim
236 words
In a vehicle having right and left ground-engaging means, a drive system comprising first and second hydraulic motors for driving said right and left ground-engaging means respectively, a pump for driving each of said hydraulic motors of the type having a variable output inversely proportional to the pressure of a hydraulic control signal, the improvement comprising, first and second pressure regulator means regulating the pressure of the control signal to said first and second pumps respectively over a range of pressures, actuators for said first and second pressure regulators, a third regulator communicating with each of said first and second regulators, means communicating the output pressures of said pumps to each of said regulators, siad first and second regulators variably communicating the output pressure back to said first and second pumps as control signals, valve means in each of said regulators responsive to said output pressures, adjustable biasing means operated by said actuators acting on said valve means whereby the greater the biasing force the greater the pressure transmitted from the regulators as control signals, said third regulator variably communicating said output pressure to said first and second regulators whereby the force of the biasing means of the first and second regulators is augmented by the pressure transmitted from said third regulator thereby providing a minimum biasing force irrespective of said adjustable biasing means and setting a lower limit on the pressures transmitted as control signals.
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |