Patent US3877538A successfully refreshed from Google Patents.
US3877538A
Expired / Lapsed
US
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Power assist device for hydrostatic drive
Assignee: Individual
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Filing: 1974-01-28
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Granted: 1975-04-15
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Expires: 1994-01-28
Abstract
Abstract A hydrostatic drive system is provided with a power assisting device in the form of a pair of hydraulic rams assist in manual manipulation of the control lever for the hydrostatic system. The hydrostatic drive system comprises a reversible hydrostatic pump which is connected in fluid communicating relation by a pair of passages to a reversible hydrostatic motor. The motor provides drive to driven members such as the ground engaging wheels of a front-end loader. The pump is controlled by a manually shiftable elongate control lever which is connected by linkage to an actuating member for the hydrostatic pump. The single acting hydraulic rams are connected to the actuating member for the pump and are arranged in opposed relation with respect to each other, and each ram is connected in communicating relation to one of said passages which interconnects the pump and motor. Each hydraulic ram will be extended when hydraulic fluid is pumped through the associated pressure passage to operate the hydraulic motor in one direction. Therefore, when a user shifts the manually operable control lever, one of the hydraulic rams will assist movement of the actuating member and facilitate movement of the manually operable control lever.
Inventors
- 👤 Douglas W Steiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:56
CPC Classifications
B; B60; B60W; B60W30/00; B60W30/18; B60W10/00; B60W10/04; B60W10/10; B60W10/101; B60W10/103; B62; B62D; B62D11/00; B62D11/02; B62D11/06; B62D11/10; B62D11/14; B62D11/18; B62D11/183; Y; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20012
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
324 words
In a hydrostatic drive device comprising: a reversible rotary hydrostatic pump having a revolvable input shaft, power means, drive connections connecting the power means with said input shaft of the hydrostatic pump, a rotary reversible hydrostatic motor having a revolvable output shaft, means defining a pair of passages each being connected in communicating relation with the pump and the motor to permit hydraulic fluid to be circulated under pressure between the pump and the motor, the output shaft of the motor being revolved in a forward direction when the fluid is pumped from the pump through one passage to the motor and returned to the pump through the other passage, the output shaft of the motor being revolved in a reverse direction when a fluid is pumped from the pump through the other passage to the motor and returned to the pump through said one passage, a manually operable shiftable elongate control lever being shiftable between forward, reverse and neutral positions, an actuating member connected with said pump and being shiftable between forward, reverse and neutral positions, said actuating member when in the forward position causing said output shaft of the motor to be driven in the forward direction, and when in the reverse position, causing said output shaft to be driven in a reverse direction, said actuating member when in the neutral position rendering said motor inoperative, an elongate motion transmitting link having one end thereof connected to said control lever and having the other end thereof connected with said actuating member, a pair of hydraulic extensible and retractable ram devices mounted adjacent said pump and each being connected to said actuating member, each ram including a cylinder and piston and being connected in a communicating relation with one of said passages, each of said rams being extended in response to the flow of fluid under pressure from the pump through the associated passage to thereby assist shifting movement of said control lever.
Claim 2
Dependent Claim
324 words
In a hydrostatic drive device comprising: a reversible rotary hydrostatic pump having a revolvable input shaft, power means, drive connections connecting the power means with said input shaft of the hydrostatic pump, a rotary reversible hydrostatic motor having a revolvable output shaft, means defining a pair of passages each being connected in communicating relation with the pump and the motor to permit hydraulic fluid to be circulated under pressure between the pump and the motor, the output shaft of the motor being revolved in a forward direction when the fluid is pumped from the pump through one passage to the motor and returned to the pump through the other passage, the output shaft of the motor being revolved in a reverse direction when a fluid is pumped from the pump through the other passage to the motor and returned to the pump through said one passage, a manually operable shiftable elongate control lever being shiftable between forward, reverse and neutral positions, an actuating member connected with said pump and being shiftable between forward, reverse and neutral positions, said actuating member when in the forward position causing said output shaft of the motor to be driven in the forward direction, and when in the reverse position, causing said output shaft to be driven in a reverse direction, said actuating member when in the neutral position rendering said motor inoperative, an elongate motion transmitting link having one end thereof connected to said control lever and having the other end thereof connected with said actuating member, a pair of hydraulic extensible and retractable ram devices mounted adjacent said pump and each being connected to said actuating member, each ram including a cylinder and piston and being connected in a communicating relation with one of said passages, each of said rams being extended in response to the flow of fluid under pressure from the pump through the associated passage to thereby assist shifting movement of said control lever.
Claim 3
Dependent Claim
26 words
The hydrostatic drive device as defined in claim 1 and pivot means pivotally mounting said actuating member for pivotal movement between forward, reverse and neutral positions.
Claim 4
Dependent Claim
379 words
A front end loader vehicle comprising a body, froNt and rear pairs of ground engaging wheels on said body, each wheel having a shaft, an engine having an output shaft, a hydrostatic drive device including: a reversible rotary hydrostatic pump having a revolvable input shaft, drive means connecting the output of the engine with said input shaft of the hydrostatic pump, a rotary reversible hydrostatic motor having a revolvable output shaft, drive connections interconnecting the output shaft of the hydrostatic motor with the shafts of a pair of ground engaging wheels on one side of the vehicle, means defining a pair of passages each being connected in communicating relation with the pump and the motor to permit hydraulic fluid to be circulated under pressure between the pump and the motor, the output shaft of the motor being revolved in a forward direction when the fluid is pumped from the pump through one passage to the motor and returned to the pump through the other passage, the output shaft of the motor being revolved in a reverse direction when a fluid is pumped from the pump through the other passage to the motor and returned to the pump through said one passage, a manually operable shiftable elongate control lever being shiftable between forward, reverse and neutral positions, an actuating member connected with said pump and being shiftable between forward, reverse and neutral positions, said actuating member when in the forward position causing said output shaft of the motor to be driven in the forward direction, and when in the reverse position causing said output shaft to be driven in a reverse direction, said actuating member when in the neutral position rendering said motor inoperative, an elongate motion transmitting link having one end thereof connected to said control lever and having the other end thereof connected with said actuating member, a pair of hydraulic extensible and retractable ram devices mounted adjacent said pump and each being connected to said actuating member, each ram including a cylinder and piston and being connected in a communicating relation with one of said passages, each of said rams being extended in response to the flow of fluid under pressure from the pump through the associated passage to thereby assist shifting movement of said control lever.
Claim 5
Dependent Claim
379 words
A front end loader vehicle comprising a body, froNt and rear pairs of ground engaging wheels on said body, each wheel having a shaft, an engine having an output shaft, a hydrostatic drive device including: a reversible rotary hydrostatic pump having a revolvable input shaft, drive means connecting the output of the engine with said input shaft of the hydrostatic pump, a rotary reversible hydrostatic motor having a revolvable output shaft, drive connections interconnecting the output shaft of the hydrostatic motor with the shafts of a pair of ground engaging wheels on one side of the vehicle, means defining a pair of passages each being connected in communicating relation with the pump and the motor to permit hydraulic fluid to be circulated under pressure between the pump and the motor, the output shaft of the motor being revolved in a forward direction when the fluid is pumped from the pump through one passage to the motor and returned to the pump through the other passage, the output shaft of the motor being revolved in a reverse direction when a fluid is pumped from the pump through the other passage to the motor and returned to the pump through said one passage, a manually operable shiftable elongate control lever being shiftable between forward, reverse and neutral positions, an actuating member connected with said pump and being shiftable between forward, reverse and neutral positions, said actuating member when in the forward position causing said output shaft of the motor to be driven in the forward direction, and when in the reverse position causing said output shaft to be driven in a reverse direction, said actuating member when in the neutral position rendering said motor inoperative, an elongate motion transmitting link having one end thereof connected to said control lever and having the other end thereof connected with said actuating member, a pair of hydraulic extensible and retractable ram devices mounted adjacent said pump and each being connected to said actuating member, each ram including a cylinder and piston and being connected in a communicating relation with one of said passages, each of said rams being extended in response to the flow of fluid under pressure from the pump through the associated passage to thereby assist shifting movement of said control lever.
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) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |