US3863518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission shifting system
Assignee: Caterpillar Inc
•
Filing: 1974-02-01
•
Granted: 1975-02-04
•
Expires: 1994-02-01
Abstract
Abstract A drive transmission for powered vehicles and the like has change speed gears which may be shifted to provide a selected one of a plurality of drive speed ratios by means of a fluid-operated control system. The control system includes a plurality of fluid energized actuating means for operating shift fork transmission elements, one of which includes neutralizing means for automatically and positively disengaging the vehicle drive line in the event of system malfunction and for disengaging the vehicle drive line when neutral is selected. Another of the actuating means includes a safety actuator for preventing simultaneous engagement of reverse and forward gears of the transmission.
Inventors
- 👤 Philip S Webber
- 👤 Joseph E Goett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:32
CPC Classifications
F; F16; F16H; F16H63/00; F16H63/02; F16H63/30; F16H63/3023; F16H61/00; F16H61/12; F16H2061/1204; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219; Y10T74/19284; Y10T74/19288; Y10T74/19293; Y10T74/19298; Y10T74/19326; Y10T74/19377; Y10T74/19414; Y10T74/19419; Y10T74/19423; Y10T74/19428; Y10T74/19433
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A drive transmissioN for coupling an engine to a driven load at any selected one of a plurality of drive ratios comprising; a plurality of coupling means for coupling selected sets of a plurality of gears, a plurality of shifting fork means for engaging said coupling means and shifting said coupling means for selecting desired gear drive ratios, actuator means associated with said shifting fork means for engaging said fork means and positioning said fork means and said coupling means, fluid pressure supply means, fluid communication means for connecting said supply means with said actuator means for actuation thereof, control means for controlling the flow of pressure fluid to said actuator means, said actuator means including a neutralizing actuator having mechanical means therein for automatically causing one of said shifting fork means to position an associated coupling means to disconnect said engine from said load when said fluid pressure drops below a predetermined value.
Claim 2
Dependent Claim
154 words
A drive transmissioN for coupling an engine to a driven load at any selected one of a plurality of drive ratios comprising; a plurality of coupling means for coupling selected sets of a plurality of gears, a plurality of shifting fork means for engaging said coupling means and shifting said coupling means for selecting desired gear drive ratios, actuator means associated with said shifting fork means for engaging said fork means and positioning said fork means and said coupling means, fluid pressure supply means, fluid communication means for connecting said supply means with said actuator means for actuation thereof, control means for controlling the flow of pressure fluid to said actuator means, said actuator means including a neutralizing actuator having mechanical means therein for automatically causing one of said shifting fork means to position an associated coupling means to disconnect said engine from said load when said fluid pressure drops below a predetermined value.
Claim 3
Dependent Claim
69 words
The invention of claim 1 wherein said neutralizing actuator includes first and second axially aligned housings disposed on axially opposite sides of said one fork means, first and second plungers disposed respectively within said first and second cylindrical bores in said first and second housings, a portion of each of said plungers directly respectively engaging one of said opposite sides of said one fork means for axial movement thereof.
Claim 4
Dependent Claim
62 words
The invention of claim 2 wherein said mechanical means of said neutralizing actuator include first and second spring means disposed respectively within said first and second cylindrical bores for normally urging each of said first and second plungers axially toward said one fork means to cause said fork means into a centered position wherein said engine is disconnected from said driven load.
Claim 5
Dependent Claim
59 words
The invention of claim 3 wherein said neutralizing actuator further includes first and second stepped pistons mounted respectively within said first and second cylindrical bores axially between said first plunger and first spring means and between said second plunger and second spring means, said spring means directly engaging said stepped pistons and said stepped pistons directly engaging said plungers.
Claim 6
Dependent Claim
100 words
The invention of claim 4 wherein said plurality of coupling means include a reverse coupling means for selectively reversing the direction of torque transmission from said engine to said load, said plurality of shifting fork means including a reverse fork means for engaging and selectively shifting said reverse coupling means, said actuator means including a safety actuator associated with said reverse fork means for engaging said fork means and preventing the simultaneous actuation of said reverse coupling means and any of said forward direction coupling means, said safety actuator including mechanical means for automatically normally disconnecting said reverse coupling means.
Claim 7
Dependent Claim
62 words
The invention of claim 5 wherein said safety actuator includes third and fourth housings having third and fourth cylindrical bores therein, and third and fourth axially opposed plungers disposed respectively within said bores, said mechanical means of said safety actuator including third spring means for normally causing said third plunger to move said reverse fork means to disconnect said reverse coupling means.
Claim 8
Dependent Claim
31 words
The invention of claim 6 wherein said safety actuator includes a third piston disposed within said third cylindrical bore between and directly engaging said third plunger and said third spring means.
Claim 9
Dependent Claim
77 words
The invention of claim 1 wherein said control means include first valve means between said supply means and said actuator means, said first valve means having a first position in which said supply means is connected to said actuator means and a second position in which said actuator means are exhausted of pressure fluid, pilot valve means for controlling the activation of said first valve means in accordance with the pressure of fluid in said supply means.
Claim 10
Dependent Claim
24 words
The invention of claim 8 wherein said first valve means includes spring means for normally biasing said first valve means into said second position.
Claim 11
Dependent Claim
53 words
The invention of claim 9 wherein said pilot valve means allows said first valve means to move to its normal second position whenever said pressure of said supply means drops below said predetermined valve to cause said actuator means to disconnect said engine from said load and to disconnect said reverse coupling means.
References Cited (Backward Citations)
US2529393A
Cited
US2924126A
Cited
US3106273A
Cited
US3508450A
Cited
US3570636A
Cited
US3667309A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |