US3862668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrostatic transmission control system
Assignee: Eaton Corp
•
Filing: 1973-06-13
•
Granted: 1975-01-28
•
Expires: 1993-06-13
Abstract
Abstract An improved straight tracking control assembly equalizes the output speeds of a pair of hydrostatic transmissions during straight forward movement of a vehicle and enables the hydrostatic transmissions to operate at different speeds during turning of the vehicle. The straight tracking control assembly includes inner and outer valve members. Each of the valve members is rotated by an input shaft at a speed which varies as a function of variations in the output speed of an associated one of the hydrostatic transmissions. As long as the two valve members are rotated at the same speed, the valve members cooperate to block fluid flow from the straight tracking control assembly to actuator assemblies which are operable to vary the output speeds of the hydrostatic transmissions. If one of the hydrostatic transmissions should be accelerated relative to the other hydrostatic transmission, relative rotation occurs between the inner and outer valve members. This results in the porting of fluid under pressure to one of the actuator assemblies to decrease the output speed of the accelerating hydrostatic transmission. Excessive relative rotation between the inner and outer valve members is prevented by a stop pin which is moved into abutting engagement with a stop surface when the valve members have been rotated through a predetermined distance relative to each other. When this occurs, a clutch assembly between one of the valve members and its input shaft begins to slip and the valve members rotate together.
Inventors
- 👤 Harold R Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:21
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/46; F16H61/47; B; B62; B62D; B62D11/00; B62D11/02; B62D11/06; B62D11/10; B62D11/14; B62D11/18; B62D11/183
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
138 words
An apparatus comprising a first hydrostatic transmission for driving one track of a vehicle, a second hydrostatic transmission for driving another track of the vehicle, first and second movable valve members, first means for moving said first valve member at a speed which varies as a function of variations in the speed at which said first hydrostatic transmission drives the one track, second means for moving said second valve member at a speed which varies as a function of variations in the speed at which said second transmission drives the other track, and means for varying the speed at which at least one of said hydrostatic transmissions drives the associated one of said tracks in response to a variation in the speed of movement of one of said valve members relative to the other of said valve members.
Claim 2
Independent Claim
138 words
An apparatus comprising a first hydrostatic transmission for driving one track of a vehicle, a second hydrostatic transmission for driving another track of the vehicle, first and second movable valve members, first means for moving said first valve member at a speed which varies as a function of variations in the speed at which said first hydrostatic transmission drives the one track, second means for moving said second valve member at a speed which varies as a function of variations in the speed at which said second transmission drives the other track, and means for varying the speed at which at least one of said hydrostatic transmissions drives the associated one of said tracks in response to a variation in the speed of movement of one of said valve members relative to the other of said valve members.
Claim 3
Dependent Claim
75 words
An apparatus as set forth in claim 1 wherein said means for varying the speed at which at least one of said hydrostatic transmission drives the associated one of said tracks includes motor means for varying the output speed of said one hydrostatic transmission, said apparatus further including steering control means for effecting operation of said motor means to vary the speed at which said one hydrostatic transmission drives the associated one of said tracks.
Claim 4
Dependent Claim
44 words
An apparatus as set forth in claim 1 further including clutch means for connecting said first means with said first valve member and for enabling said first valve member to move with said second valve member under the influence of said second drive means.
Claim 5
Dependent Claim
121 words
An apparatus as set forth in claim 1 wherein said means for varying the speed at which at least one of said hydrostatic transmission drives the associated one of said tracks includes a double acting hydraulic motor having a first and second operating chamber, conduit means for connecting said first and second operating chambers in fluid communication with at least one of said valve members, and valve means for connecting said one of said valve members in fluid communication with said first chamber during operation of said one hydrostatic transmission in a first direction and for connecting said one of said valve members in fluid communication with said second chamBer during operaation of said one hydrostatic transmission in a second direction.
Claim 6
Dependent Claim
57 words
An apparatus as set forth in claim 4 further including speed control valve means for varying the fluid pressure conducted to said second chamber during operation of said one hydrostatic transmission in said first direction and for varying the fluid pressure conducted to said first chamber during operation of said one hydrostatic transmission in said second direction.
Claim 7
Dependent Claim
76 words
An apparatus as set forth in claim 1 further including stop means for limiting relative movement between said first and second valve members to a predetermined range of movement, and steering control means for effecting operation of one of said hydrostatic transmissions at a greater speed than the other hydrostatic transmission to effect a turning of the vehicle, said stop means being effective during turning of the vehicle to limit relative movement between said valve members.
Claim 8
Dependent Claim
206 words
An apparatus as set forth in claim 1 further including valve housing means for defining a first chamber, said first valve member being at least partially disposed in said first chamber and including means for defining a second chamber, said second valve member being at least partially disposed in said second chamber, said second valve member including means for at least partially defining a pressure chamber, first conduit means for connecting said pressure chamber in fluid communication with a source of fluid under pressure, and second conduit means for connecting said pressure chamber with said means for varying the speed of at least one of said hydrostatic transmissions, said first and second valve members including means for limiting fluid pressure conducted from said pressure chamber to said second fluid conduit means during operation of said first and second hydrostatic transmissions to drive the tracks of the vehicle at the same speed and for enabling fluid to flow from said pressure chamber to said second fluid conduit means when the speed at which one of the tracks is driven by an associated one of said hydrostatic transmissions is different than the speed at which the other track is driven by the associated one of said hydrostatic transmissions.
Claim 9
Dependent Claim
60 words
An apparatus as set forth in claim 7 further including selectively actuatable control means for effecting operation of one of said hydrostatic transmissions to drive one of the tracks at a slower speed than the other track to effect a turning of the vehicle, said control means including means for limiting fluid under pressure during actuation of said control means.
Claim 10
Dependent Claim
43 words
An apparatus as set forth in claim 1 further including stop means for preventing relative movement in one direction between said first and second valve members after said first and second valve members have moved through a predetermined distance in the one direction.
Claim 11
Dependent Claim
47 words
An apparatus as set forth in claim 9 further including clutch means interconnecting said first means and first valve member for enabling said first valve member to move relative to said first means upon operation of said stop means to prevent relative movement between said valve members.
Claim 12
Dependent Claim
40 words
An apparatus as set forth in claim 9 wherein said stop means includes means for operatively interconnecting said first and second valve members after movement of said first and second valve members through the predetermined distance in the one direction.
Claim 13
Independent Claim
265 words
An apparatus for controlling the operation of an actuator assembly which is operable to vary the output speed of an associated one of a pair of hydrostatic transmissions, said apparatus comprising a housing defining a valve chamber, inlet means for connecting said valve chamber in fluid communication with a source of fluid under pressure, outlet means for connecting said valve chamber in fluid communication with the actuator assembly, a first valve member at least partially disposed in said housing, first rotatable input means for rotating said first valve member at a speed which varies as a fuNction of variations in the operating speed of an associated one of the pair of hydrostatic transmissions, a second valve member at least partially disposed in said valve chamber, second rotatable input means for rotating said second valve member at a speed which varies as a function of variations in the operating speed of the other one of the pair of hydrostatic transmissions, said first and second valve members including means for limiting fluid communication between said inlet and outlet means during rotation of said first and second valve members at the same speed by said first and second input means and for connecting said inlet and outlet means in fluid communication upon relative rotation between said first and second valve members, and clutch means for interconnecting one of said valve members and one of said input means and for enabling said one valve member to rotate with the other valve member relative to said one input means during continued operation of the hydrostatic transmissions at different output speeds.
Claim 14
Independent Claim
265 words
An apparatus for controlling the operation of an actuator assembly which is operable to vary the output speed of an associated one of a pair of hydrostatic transmissions, said apparatus comprising a housing defining a valve chamber, inlet means for connecting said valve chamber in fluid communication with a source of fluid under pressure, outlet means for connecting said valve chamber in fluid communication with the actuator assembly, a first valve member at least partially disposed in said housing, first rotatable input means for rotating said first valve member at a speed which varies as a fuNction of variations in the operating speed of an associated one of the pair of hydrostatic transmissions, a second valve member at least partially disposed in said valve chamber, second rotatable input means for rotating said second valve member at a speed which varies as a function of variations in the operating speed of the other one of the pair of hydrostatic transmissions, said first and second valve members including means for limiting fluid communication between said inlet and outlet means during rotation of said first and second valve members at the same speed by said first and second input means and for connecting said inlet and outlet means in fluid communication upon relative rotation between said first and second valve members, and clutch means for interconnecting one of said valve members and one of said input means and for enabling said one valve member to rotate with the other valve member relative to said one input means during continued operation of the hydrostatic transmissions at different output speeds.
Claim 15
Dependent Claim
36 words
An apparatus as set forth in claim 12 further including means for interconnecting said first and second valve members for rotation together relative to said housing during continued operation of the hydrostatic transmissions at different speeds.
Claim 16
Dependent Claim
51 words
An apparatus as set forth in claim 12 wherein said clutch means includes a first circular clutch surface connected with said one of said valve members, a second circular clutch surface connected with said one input means and spring means for urging said first and second clutch surfaces into pressure engagement.
Claim 17
Independent Claim
235 words
An apparatus for controlling the operation of an actuator assembly which is operable to vary the output speed of an associated one of a pair of hydrostatic transmissions said apparatus comprising a housing defining a valve chamber, inlet means for connecting said valve chamber in fluid communication with a source of fluid under pressure, outlet means for connecting said valve chamber in fluid communication with the actuator assembly, a first valve member at least partially disposed in said housing, first rotatable input means for rotating said first valve member at a speed which varies as a function of variations in the operating speed of an associated one of the pair of hydrostatic transmissions, a second valve member at least partially disposed in said valve chamber, second rotatable input means for rotating said second valve member at a speed which varies as a function of variations in the operating speed of the other one of the pair of hydrostatic transmissions, said first and second valve members including means for limiting fluid communication between said inlet and outlet means during rotation of said first and second valve members at the same speed by said first and second input means and for connecting said inlet and outlet means in fluid communication upon relative rotation between said first and second valve members, and stop means for limiting the extent of relative rotation between said first and second valve members.
Claim 18
Independent Claim
235 words
An apparatus for controlling the operation of an actuator assembly which is operable to vary the output speed of an associated one of a pair of hydrostatic transmissions said apparatus comprising a housing defining a valve chamber, inlet means for connecting said valve chamber in fluid communication with a source of fluid under pressure, outlet means for connecting said valve chamber in fluid communication with the actuator assembly, a first valve member at least partially disposed in said housing, first rotatable input means for rotating said first valve member at a speed which varies as a function of variations in the operating speed of an associated one of the pair of hydrostatic transmissions, a second valve member at least partially disposed in said valve chamber, second rotatable input means for rotating said second valve member at a speed which varies as a function of variations in the operating speed of the other one of the pair of hydrostatic transmissions, said first and second valve members including means for limiting fluid communication between said inlet and outlet means during rotation of said first and second valve members at the same speed by said first and second input means and for connecting said inlet and outlet means in fluid communication upon relative rotation between said first and second valve members, and stop means for limiting the extent of relative rotation between said first and second valve members.
Claim 19
Dependent Claim
86 words
An apparatus as set forth in claim 15 wherein said stop means includes a stop element connected with one of said valve members, first stop surface means connected with the other of said valve members for engaging said stop element to limit relative rotation between said first and second valve members in a first direction, and second stop surface means connected with said other valve member for engaging said stop element to limit relative rotation between said first and second valve members in a second direction.
Claim 20
Dependent Claim
53 words
An apparatus as set forth in claim 16 further including clutch means for interconnecting one of said valve member and one of said input means and for enabling the one valve member to rotate relative to the one input means upon engagement of said stop element with one of said stop surface means.
Claim 21
Independent Claim
220 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable Displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, steering valve means connected in fluid communication with said first and second fluid motor means for effecting operation of said first fluid motor means and a turning of the vehicle in a first direction and for effecting operation of said second fluid motor means and a turning of the vehicle in a second direction, straight tracking control means for effecting operation of said first fluid motor means upon a change in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said second fluid motor means upon a change in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, and means for rendering said straight tracking control means ineffective to effect operation of said first and second fluid motor means upon operation of said steering valve means.
Claim 22
Independent Claim
220 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable Displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, steering valve means connected in fluid communication with said first and second fluid motor means for effecting operation of said first fluid motor means and a turning of the vehicle in a first direction and for effecting operation of said second fluid motor means and a turning of the vehicle in a second direction, straight tracking control means for effecting operation of said first fluid motor means upon a change in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said second fluid motor means upon a change in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, and means for rendering said straight tracking control means ineffective to effect operation of said first and second fluid motor means upon operation of said steering valve means.
Claim 23
Dependent Claim
65 words
An apparatus as set forth in claim 19 further including first conduit means for conducting fluid under pressure to said straight tracking control means, second conduit means for conducting fluid under pressure from said straight tracking control means to said first fluid motor means, and third conduit means for conducting fluid under pressure from said straight tracking control means to said second fluid motor means.
Claim 24
Dependent Claim
40 words
An apparatus as set forth in claim 19 wherein said means for rendering said straight tracking control means ineffective includes means for limiting fluid flow through at least one of said conduit means upon operation of said steering control means.
Claim 25
Dependent Claim
40 words
An apparatus as set forth in claim 19 wherein said means for rendering said straight tracking control means ineffective includes means for limiting fluid flow through said second and third conduit means upon operation of said steering control valve means.
Claim 26
Dependent Claim
126 words
An apparatus as set forth in claim 19 wherein said steering valve means includes a first manually actuated valve means for porting fluid under pressure to said first fluid motor means to effect a turning of the vehicle in the first direction and a second manually actuatable valve means for porting fluid under pressure to said second fluid motor means to effect a turning of the vehicle in the second direction, said means for rendering said straight tracking control means ineffective including means for limiting fluid flow through at least one of said conduit means upon operation of said first manually actuatable valve means for and for fluid flow through at least one of said conduit means upon operation of said second manually actuatable valve means.
Claim 27
Dependent Claim
110 words
An apparatus as set forth in claim 19 wherein said straight tracking control means includes straight tracking valve means for porting fluid under pressure from said first conduit means to said second conduit means upon a change in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for porting fluid under pressure from said first conduit means to said third conduit means upon a change in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven.
Claim 28
Dependent Claim
91 words
An apparatus as set forth in claim 23 wherein said straight tracking valve means includes first and second valve members, said straight tracking control means including first input means for moving said first valve member at a speed which varies as a function of variations in the speed at which said first hydrostatic transmission drives the one track and second input means for moving said second valve member at a speed which varies as a function of variations in the speed at which said second hydrostatiC transmission drives the other track.
Claim 29
Dependent Claim
57 words
An apparatus as set forth in claim 24 wherein said straight tracking control means further includes clutch means for interconnecting said first input means and said first valve member and for enabling relative movement to occur between said first valve member and said first input means during continued operation of said hydrostatic transmissions at different output speeds.
Claim 30
Dependent Claim
50 words
An apparatus as set forth in claim 25 further including stop means for limiting the extent of relative movement between said first and second valve members and for effecting operation of said clutch means to enable relative movement to occur between said first valve member and said first input means.
Claim 31
Independent Claim
383 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, first steering valve means connected with said first fluid motor means and operable from an unactuated condition to an actuated condition to effect operation of said first fluid motor means and a turning of the vehicle in a first direction, second steering valve means connected with said second fluid motor means and operable from an unactuated condition to an actuated condition to effect operation of said second fluid motor means and a turning of the vehicle in a second direction, and straight tracking control means for effecting operation of said first and second fluid motor means to maintain the speeds at which the tracks are driven substantiallly equal during straight forward movement of the vehicle, said straight tracking control means including straight tracking valve means operable from an initial condition to a first actuated condition to effect operation of said first fluid motor means to vary the speed at which the one track of the vehicle is driven relative to the speed at which the ohter track of the vehicle is driven, said straight tracking valve means being operable from said initial condition to a second actuated condition to effect operation of said second fluid motor means to vary the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, and means for effecting operation of said straight tracking valve means from said initial condition to said first actuated condition in response to a variation in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said straight tracking valve means from said initial condition to said second actuated condition in response to a variation in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven.
Claim 32
Independent Claim
383 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, first steering valve means connected with said first fluid motor means and operable from an unactuated condition to an actuated condition to effect operation of said first fluid motor means and a turning of the vehicle in a first direction, second steering valve means connected with said second fluid motor means and operable from an unactuated condition to an actuated condition to effect operation of said second fluid motor means and a turning of the vehicle in a second direction, and straight tracking control means for effecting operation of said first and second fluid motor means to maintain the speeds at which the tracks are driven substantiallly equal during straight forward movement of the vehicle, said straight tracking control means including straight tracking valve means operable from an initial condition to a first actuated condition to effect operation of said first fluid motor means to vary the speed at which the one track of the vehicle is driven relative to the speed at which the ohter track of the vehicle is driven, said straight tracking valve means being operable from said initial condition to a second actuated condition to effect operation of said second fluid motor means to vary the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, and means for effecting operation of said straight tracking valve means from said initial condition to said first actuated condition in response to a variation in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said straight tracking valve means from said initial condition to said second actuated condition in response to a variation in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven.
Claim 33
Dependent Claim
62 words
An apparatus as set forth in claim 27 further including means for rendering said straight tracking valve means ineffective to effect operation of said first fluid motor means upon operation of said first steering valve means and for rendering said straight tracking valve mans ineffective to effect operation of said second fluid motor means upon operation of said second steering valve means.
Claim 34
Dependent Claim
144 words
An apparatus as set forth in claim 27 wherein said means for effecting operation of said straight tracking valve means includes a first input member which rotates at a speed which varies with variations in the speed at which the one track of the vehicle is driven, a second input member which rotates at a speed which varies with variations in the speed at which the other track of the vehicle is driven, and means for effecting operation of said straight tracking valve means from said initial condition to said first actuated condition upon rotation of said first inPut member at a faster speed than said second input member and for effecting operation of said straight tracking valve means from said initial condition to said second actuated condition upon rotation of said second input member at a faster speed than said first input member.
Claim 35
Independent Claim
401 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, straight tracking control means for effecting operation of said first and second fluid motor means to maintain the speeds at which the tracks are driven substantially equal during straight forward movement of the vehicle, said straight tracking control means including straight tracking valve means operable from an initial condition to a first actuated condition to port fluid pressure and effect operation of said first fluid motor means to vary the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven, said straight tracking valve means being operable from said initial condition to a second actuated condition to port fluid pressure and effect operation of said second fluid motor means to vary the speed at which the other track of the vehicle is drive relative to the speed at which the one track of the vehicle is driven, and means for effecting operation of said straight tracking valve means from said initial condition to said first actuated condition in response to a variation in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said straight tracking valve means from said initial condition to said second actuated condition in response to a variation in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, first steering valve means operable from an unactuated condition to an actuated condition to port fluid pressure to render said straight tracking control means ineffective and to effect operation of said first fluid motor means and a turning of the vehicle in a first direction, and second steering valve means operable from an unactuated condition to an actuated condition to port fluid pressure to render said straight tracking control means ineffective and to effect operation of said second fluid motor means and a turning of the vehicle in a second direction.
Claim 36
Independent Claim
401 words
An apparatus comprising a first variable displacement hydrostatic transmission for driving one track of a vehicle, a second variable displacement hydrostatic transmission for driving another track of a vehicle, first fluid motor means for varying the displacement of said first hydrostatic transmission, second fluid motor means for varying the displacement of said second hydrostatic transmission, straight tracking control means for effecting operation of said first and second fluid motor means to maintain the speeds at which the tracks are driven substantially equal during straight forward movement of the vehicle, said straight tracking control means including straight tracking valve means operable from an initial condition to a first actuated condition to port fluid pressure and effect operation of said first fluid motor means to vary the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven, said straight tracking valve means being operable from said initial condition to a second actuated condition to port fluid pressure and effect operation of said second fluid motor means to vary the speed at which the other track of the vehicle is drive relative to the speed at which the one track of the vehicle is driven, and means for effecting operation of said straight tracking valve means from said initial condition to said first actuated condition in response to a variation in the speed at which the one track of the vehicle is driven relative to the speed at which the other track of the vehicle is driven and for effecting operation of said straight tracking valve means from said initial condition to said second actuated condition in response to a variation in the speed at which the other track of the vehicle is driven relative to the speed at which the one track of the vehicle is driven, first steering valve means operable from an unactuated condition to an actuated condition to port fluid pressure to render said straight tracking control means ineffective and to effect operation of said first fluid motor means and a turning of the vehicle in a first direction, and second steering valve means operable from an unactuated condition to an actuated condition to port fluid pressure to render said straight tracking control means ineffective and to effect operation of said second fluid motor means and a turning of the vehicle in a second direction.
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) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |