US3843205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forward reverse drive control providing automatic braking
Assignee: International Motors LLC
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Filing: 1971-06-03
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Granted: 1974-10-22
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Expires: 1991-06-03
Abstract
Abstract Tractor having dump valve and forward-reverse drive control employing same, effective to automatically brake the tractor when reversing the tractor''s direction of motion. The tractor has brakes, a reversible transmission controlled by the dump valve, a range selector valve having a control portion, and a run detector pump to sense direction of rolling movement of the tractor and having a directionalized pump output. The dump valve generally receives against pressure movable end areas thereof an output from the range selector valve and directs control pressure to operate the brakes and transmission in alternation to one another and, specifically: receives against the pressure movable end areas the directionalized pump output so as to be hydraulically balanced in a centered position operating the tractor with transmission engaged and brakes disengaged; receives against the pressure movable end areas an unbalancing force from the range selector valve control portion causing the dump valve to shift off center and dump, neutralizing the transmission and setting the brakes; and having valve springs effective to mechanically rebalance the dump valve attendant with slow down of the run detector pump, causing the dump valve to recenter, releasing the brakes and engaging the transmission in an opposite drive setting.
Inventors
- 👤 D Shore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:14
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0262; F16H61/0265; F16H61/0272; B; B60; B60W; B60W10/00; B60W10/04; B60W10/10; B60W10/18; B62; B62D; B62D11/00; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87169; Y10T137/87217; Y10T137/87225
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
192 words
In combination: a control valve assembly comprising a housing having high (126), transfer (110), and low (114, 116) pressure chambers; a common bore intersecting the chambers; individual valve bores in communication with the transfer and low pressure chambers and with plural service passages (84, 86, 88, 90) in said housing; first and second range selector valve elements (F1 F2, R2 R1) each shiftably disposed in a different one of the individual valve bores, said valve elements being movable selectively from a position interconnecting the aforesaid low pressure chamber and the service passages to discreet operating positions at once interconnecting the transfer chamber and selected service passage and interconnecting the low pressure chamber and the unselected service passagfes; a dump valve element (CD) shiftably disposed in said common bore and having an undisplaced, satisfied position interconnecting the transfer and high pressure chambers and a displaced, dump position interconnecting the transfer and low pressure chambers; and means including pressure movable control means (104, 124) carried by the dump valve element for shifting same selectively to make available high pressure to, or to dump the pressure from, the transfer passage and the selected service passage.
Claim 2
Dependent Claim
192 words
In combination: a control valve assembly comprising a housing having high (126), transfer (110), and low (114, 116) pressure chambers; a common bore intersecting the chambers; individual valve bores in communication with the transfer and low pressure chambers and with plural service passages (84, 86, 88, 90) in said housing; first and second range selector valve elements (F1 F2, R2 R1) each shiftably disposed in a different one of the individual valve bores, said valve elements being movable selectively from a position interconnecting the aforesaid low pressure chamber and the service passages to discreet operating positions at once interconnecting the transfer chamber and selected service passage and interconnecting the low pressure chamber and the unselected service passagfes; a dump valve element (CD) shiftably disposed in said common bore and having an undisplaced, satisfied position interconnecting the transfer and high pressure chambers and a displaced, dump position interconnecting the transfer and low pressure chambers; and means including pressure movable control means (104, 124) carried by the dump valve element for shifting same selectively to make available high pressure to, or to dump the pressure from, the transfer passage and the selected service passage.
Claim 3
Dependent Claim
258 words
In pressure adjustable valving for directing hydraulic flow wherein the valving is communicatively disposed between a source of high and low pressure and a hydraulically actuated mechanism, the combination comprising: a valve casing (78) having a common transfer channel (110), said casing further having a common low pressure channel and a high pressure channel (126) for connection respectively to low pressure and to high pressure of said source, and plural bores individual ones of which intersect both of the aforesaid commonchannels and at least an upstream one of which intersects said high pressure channel; a first valve spool (CD) shiftably disposed in the just-named upstream bore, having a satisfied position in which it directs the high pressure into the transfer channel, and a displaced position in which it dumps the transfer channel to the low pressure; a downstream one of the bores having service passages intersecting same and including therein a valve spool (R2R1 or F1F2) shiftable selectively from a position interconnecting the low pressure channel and the service passages, to iscrete operating positions at once interconnecting the transFer channel and a selected service passage and interconnecting the low pressure channel and an unselected service passage; means including a pressure movable area (104 or 124) carried by the first valve spool for shifting same to dump pressure from the transfer channel and the selected service passage; and means including a control device (138 or 122) establishing cooperation with the first valve spool for shifting same tothe satisfied position to make available high pressure to the selected service passage.
Claim 4
Dependent Claim
258 words
In pressure adjustable valving for directing hydraulic flow wherein the valving is communicatively disposed between a source of high and low pressure and a hydraulically actuated mechanism, the combination comprising: a valve casing (78) having a common transfer channel (110), said casing further having a common low pressure channel and a high pressure channel (126) for connection respectively to low pressure and to high pressure of said source, and plural bores individual ones of which intersect both of the aforesaid commonchannels and at least an upstream one of which intersects said high pressure channel; a first valve spool (CD) shiftably disposed in the just-named upstream bore, having a satisfied position in which it directs the high pressure into the transfer channel, and a displaced position in which it dumps the transfer channel to the low pressure; a downstream one of the bores having service passages intersecting same and including therein a valve spool (R2R1 or F1F2) shiftable selectively from a position interconnecting the low pressure channel and the service passages, to iscrete operating positions at once interconnecting the transFer channel and a selected service passage and interconnecting the low pressure channel and an unselected service passage; means including a pressure movable area (104 or 124) carried by the first valve spool for shifting same to dump pressure from the transfer channel and the selected service passage; and means including a control device (138 or 122) establishing cooperation with the first valve spool for shifting same tothe satisfied position to make available high pressure to the selected service passage.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |