Patent US6594628B1 successfully refreshed from Google Patents.
Patent US3889759A successfully refreshed from Google Patents.
US3889759A
Expired / Lapsed
US
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Hydraulically propelled vehicle
Assignee: Caterpillar Paving Products Inc
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Filing: 1974-02-04
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Granted: 1975-06-17
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Expires: 1994-02-04
Abstract
Abstract An earthworking machine having front and rear traction means and a hydraulic motor for each. The motors are connected in a closed loop parallel circuit with a pump, and one of them drives its traction means through a plural speed transmission. A first valve mechanism divides pump output fluid equally between the motors. An orifice device in the motor-pump circuit allows up to a predetermined small amount of fluid flowing to either motor to be diverted to the other motor. Second valve means in the hydraulic circuit maintains the first valve mechanism effective except at times when the transmission is in other than a low speed working position.
Inventors
- 👤 Roger L Larson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:17
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/38; F16H61/40; F16H61/44; F16H61/456; E; E01; E01C; E01C19/00; E01C19/22; E01C19/23; E01C19/26; E01C19/266; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/78; E02F3/96; E02F3/961; B; B60; B60K; B60K17/00; B60K17/04; B60K17/10; B60K17/105
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
268 words
In an earth working machine having traction wheels at its rear and a compacting drum and leveling blade at its front, the compacting drum being power driven to coact with the traction wheels in effecting propulsion of the machine and being rotatably connected with a yoke that projects forwardly from the chassis of the machine, and the leveling blade being mounted on said yoke ahead of the compacting drum for maximum effectiveness, said machine being characterized by an improved propulsion system which assures continued propulsion of the machine regardless of diminished traction between the drum and ground due to the inevitable upward force on the yoke resulting from loading of the leveling blade during use thereof, and which improved propulsion system comprises: A. a power driven bidirectional hydraulic pump; B. a reversible hydraulic motor drivingly connected with the drum; C. a second reversible hydraulic motor drivingly connected with the traction wheels; D. a closed loop parallel hydraulic circuit including supply lines leading to the hydraulic motors connecting the pump with the hydraulic motors and through which pressure fluid is delivered to both of said motors; and E. an equal ratio flow divider-combiner valve mechanism connected in one side of said closed loop hydraulic circuit to divide the pressure fluid issuing from the pump and flowing to the hydraulic motors into substantially equal volumes so that reduction in the load on the hydraulic motor driving the drum and resulting from loss of traction between the drum and ground as a consequence of increased loading of the leveling blade will not diminish traction at the rear wheels of the machine.
Claim 2
Dependent Claim
268 words
In an earth working machine having traction wheels at its rear and a compacting drum and leveling blade at its front, the compacting drum being power driven to coact with the traction wheels in effecting propulsion of the machine and being rotatably connected with a yoke that projects forwardly from the chassis of the machine, and the leveling blade being mounted on said yoke ahead of the compacting drum for maximum effectiveness, said machine being characterized by an improved propulsion system which assures continued propulsion of the machine regardless of diminished traction between the drum and ground due to the inevitable upward force on the yoke resulting from loading of the leveling blade during use thereof, and which improved propulsion system comprises: A. a power driven bidirectional hydraulic pump; B. a reversible hydraulic motor drivingly connected with the drum; C. a second reversible hydraulic motor drivingly connected with the traction wheels; D. a closed loop parallel hydraulic circuit including supply lines leading to the hydraulic motors connecting the pump with the hydraulic motors and through which pressure fluid is delivered to both of said motors; and E. an equal ratio flow divider-combiner valve mechanism connected in one side of said closed loop hydraulic circuit to divide the pressure fluid issuing from the pump and flowing to the hydraulic motors into substantially equal volumes so that reduction in the load on the hydraulic motor driving the drum and resulting from loss of traction between the drum and ground as a consequence of increased loading of the leveling blade will not diminish traction at the rear wheels of the machine.
Claim 3
Dependent Claim
92 words
The invention defined by claim 1 further characterized by a pressure compensated orifice device connected in said hydraulic circuit in parallel with the equal ratio flow divider-combiner valve mechanism, said orifice device modifying the fixed ratio aspect of the flow divider-combiner valve mechanism by allowing a predetermined maximum amount of flow to pass between the supply lines leading to the two hydraulic motors to thereby compensate for change in the volumetric efficiency of the motors resulting from an increase in the rolling radius of the traction wheels by buildup of material thereon.
Claim 4
Dependent Claim
16 words
an orifice device through which the ports of said one motor are connectible with one another,
Claim 5
Dependent Claim
16 words
an orifice device through which the ports of said one motor are connectible with one another,
Claim 6
Dependent Claim
53 words
and a valve mechanism movable from a first position communicating the ports of said one motor to a second position disrupting said last named communication; H. and means to effect actuation of said valve mechanism to said second position thereof in consequence of actuation of the transmission means to a low speed position.
Claim 7
Dependent Claim
53 words
and a valve mechanism movable from a first position communicating the ports of said one motor to a second position disrupting said last named communication; H. and means to effect actuation of said valve mechanism to said second position thereof in consequence of actuation of the transmission means to a low speed position.
Claim 8
Dependent Claim
160 words
The invention defined by claim 1, wherein the hydraulic motor driving the rear traction wheels is drivingly connected therewith through a plural speed transmission having operator-controlled gear shifting means by which the transmission can be shifted from one to another of its speeds, and further characterized by a bypass passage connected in the hydraulic circuit in parallel with said equal raTio flow divider-combiner valve mechanism to communicate said supply lines leading to the hydraulic motors when said passage is open and thereby nulify the effect of the equal ratio flow divider-combiner valve mechanism on the functioning of the system but when closed having no affect thereon; a valve in said bypass passage; said valve being closed when the plural speed transmission is in its low speed mode; and means operable in response to actuation of the operator-controlled gear shifting means in taking the transmission out of its low speed mode, to effect opening of said valve in the bypass passage.
Claim 9
Dependent Claim
188 words
In combination with an earth working machine having a compacting drum at its front, and wheels at its rear: A. a yoke having arms embracing the opposite axial ends of the drum and in which the drum is journalled for rotation on a transverse axis; B. a levelling blade carried by the yoke arms and located ahead of the drum; C. means for transmitting rotation to the drum comprising a first reversible fluid motor having a pair of ports; D. means for transmitting rotation to the wheels comprising a second reversible fluid motor having a pair of ports, and plural speed transmission means drivingly connecting the wheels with said second motor; E. a bidirectional pump having a pair of work ports; F. means connecting said motors in a closed loop parallel circuit with the pump, comprising a first duct connecting with one of each of the motor ports and having a branch connecting with one of the work ports of the pump, and a second duct connecting the other pump port with the other of said motor ports; G. valve instrumentalities connecting with said first duct and comprising
Claim 10
Dependent Claim
188 words
In combination with an earth working machine having a compacting drum at its front, and wheels at its rear: A. a yoke having arms embracing the opposite axial ends of the drum and in which the drum is journalled for rotation on a transverse axis; B. a levelling blade carried by the yoke arms and located ahead of the drum; C. means for transmitting rotation to the drum comprising a first reversible fluid motor having a pair of ports; D. means for transmitting rotation to the wheels comprising a second reversible fluid motor having a pair of ports, and plural speed transmission means drivingly connecting the wheels with said second motor; E. a bidirectional pump having a pair of work ports; F. means connecting said motors in a closed loop parallel circuit with the pump, comprising a first duct connecting with one of each of the motor ports and having a branch connecting with one of the work ports of the pump, and a second duct connecting the other pump port with the other of said motor ports; G. valve instrumentalities connecting with said first duct and comprising
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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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |