Transmission control system

Claim 2

A control for a multi-speed planetary gear transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; first, second, and third relay valve means in fluid communication with said pump means and each being moveable to a spring set position and a pressure set position for controlling fluid from said pump means; first, second and third shift valve means each being moveable to a spring set position and a pressure controlled position for controlling the engagement of first, second, and third of said drive establishing means respectively; first fluid passage means in fluid communication with said second relay valve means and said first, second, and third shift valve means for providing pressurized fluid from said pump means through said second relay valve means when said second relay valve means is in the spring set position and providing an exhaust connection when said second relay valve means is in the pressure set position; second fluid passage means in fluid communication with said second shift valve means, said first and third relay valve means and the second drive establishing means for directing pressurized fluid in said first passage means to said first and third relay valve means to control movement thereof to said pressure set position, and to the second drive establishing means for controlling engagement thereof when said second shift valve means is in the spring set position and for permitting exhausting of the pressurized fluid therein to control movement of said first and third relay valve means to the spring set position and the engagement pressure of the second drive establishing means when said second shift valve is in said pressure controlled position; third passage means in fluid communication with said first shift valve means and said first relay valve means and being in fluid communication with said first passage means when said first shift valve means is in said spring set position and to exhaust when said first shift valve means is in said pressure controlled position for directing fluid pressure to and from said first relay valve means to control movement thereof between the spring set and pressure set positions thereof; and fourth passage means in fluid communication with said third shift valve means and said third relay valve means and being in fluid communication with said first passage means when said third shift valve means is in the spring set position and to exhaust when said third shift valve means is in said pressure controlled position for directing fluid pressure to and from said third relay valve means to control movement thereof between the spring set and pressure set positions thereof.

Claim 3

A control for a multi-speed planetary gearing transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing low, intermediate, and high drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; low, intermediate, and high shift valve means each being selectively operable between a spring set and pressure controlled position, for establishing said low, intermediate, and high drive ratios, being moveable to the pressure controlled position for ratio interchange and returning to the spring set position on ratio establishment; relay valve means for each of said low, intermediate, and high shift valve means and each being selectively operable to a spring set position for delivering fluid pressure between said pump means and said shift valve means and a pressure set position for exhausting pressure at said shift valve means; and passage means interconnecting said pump means, said relay valve means, said shift valve means and said drive establishing means for maintaining the intermediate drive ratio established and maintaining the relay valve means for the low and high shift vaLve means in the pressure set position when the high or intermediate or low shift valve means do not function properly by moving to the pressure controlled position on an upshift from intermediate to high or on a downshift from intermediate to low.

Claim 4

A control for a multi-speed planetary gearing transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing low, intermediate, and high drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; low, intermediate, and high shift valve means each being selectively operable between a spring set and pressure controlled position, for establishing said low, intermediate, and high drive ratios, being moveable to the pressure controlled position for ratio interchange and returning to the spring set position on ratio establishment; relay valve means for each of said low, intermediate, and high shift valve means and each being selectively operable to a spring set position for delivering fluid pressure between said pump means and said shift valve means and a pressure set position for exhausting pressure at said shift valve means; and passage means interconnecting said pump means, said relay valve means, said shift valve means and said drive establishing means for maintaining the intermediate drive ratio established and maintaining the relay valve means for the low and high shift vaLve means in the pressure set position when the high or intermediate or low shift valve means do not function properly by moving to the pressure controlled position on an upshift from intermediate to high or on a downshift from intermediate to low.

Claim 5

A control for a multi-speed planetary gear transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; first, second, third, and fourth relay valve means in fluid communication with said pump means and each being moveable to a spring set position and a pressure set position for controlling fluid from said pump means; first, second, third, and fourth shift valve means each being moveable to a spring set position and a pressure controlled position for controlling the engagement of first, second, third, and fourth of said drive establishing means respectively; first fluid passage means in fluid communication with said second relay valve means, said first, second and third shift valve means and said fourth relay valve means for providing pressurized fluid from said pump means through said second relay valve means when said second relay valve means is in the spring set position and providing an exhaust connection when said second relay valve means is in the pressure set position and for moving said fourth relay valve means to said pressure set position; second fluid passage means in fluid communication with said second shift valve means, said first and third relay valve means and the second drive establishing means for directing pressurized fluid in said first passage means to said first and third relay valve means to control movement thereof to said pressure set position, and to the second drive establishing means for controlling engagement thereof when said second shift valve means and second relay valve means are in the spring set position and for permitting exhausting of the pressurized fluid therein to control movement of said first and third relay valve means to the spring set position and for controlling the engagement pressure of the second drive establishing means when said second shift valve is in said pressure controlled position; third passage means in fluid communication with said first shift valve means and said first relay valve means and being in fluid communication with said first passage means when said first shift valve means is in said spring set position and to exhaust when said first shift valve means is in said pressure controlled position for directing fluid pressure to and from said first relay valve means to control movement thereof between the spring set and pressure set positions thereof; fourth passage means in fluid communication with said third shift valve means and said third relay valve means and being in fluid communication with said first passage means when said third shift valve means is in the spring set position and to exhaust when said third shift valve means is in said pressure controlled position for directing fluid pressure to and from said third relay valve means to control movement thereof between the spring set and pressure set positions thereof; said first and second passage means remaining pressurized to prevent a ratio change from second to first and from second to third when said second shift valve means is in said spring set position; said first and third passage means remaining pressurized to prevent a ratio change from second to first when said second shift valve means is in said pressure controlled position and said first shift valve means is in said spring set position; said first and fourth passage means remaining pressurized to prevent a ratio change from second to third when said second shift valve means is in said pressure controlled position and said third shift valve means is in said spring set position; fifth passage means in fluid communication with said third relay valve means, said second, third, aNd fourth shift valve means and said first relay valve means for providing pressurized fluid from said pump means through said third relay valve means when said third relay valve means is in said spring set position and for providing an exhaust connection when said third relay valve means is in the pressure set position, and for moving said first relay valve means to said pressure set position when said third relay valve means is in said spring set position; sixth passage means for providing fluid communication between said third shift valve means and said third drive establishing means to establish engagement thereof, said second relay valve means and said fourth relay valve means; seventh passage means for providing fluid communication between said second shift valve means and said second relay valve means; and eighth passage means for providing fluid communication between said fourth shift valve means and said fourth relay valve means; said fifth and sixth passage means remaining pressurized to prevent a ratio change from third to second and from third to fourth when said third relay valve means and said third shift valve means are in said spring set positions; said fifth and seventh passage means remaining pressurized to prevent a ratio change from third to second when said third relay valve means and said second shift valve means are in said spring set positions and said third shift valve means is in said pressure controlled position; said fifth and eighth passage means remaining pressurized to prevent a ratio change from third to fourth when said third relay valve means and said fourth shift valve means are in said spring positions and said third shift valve means is in said pressure controlled position.

Claim 6

A control for a multi-speed planetary gear transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; first, second, third, and fourth relay valve means in fluid communication with said pump means and each being moveable to a spring set position and a pressure set position for controlling fluid from said pump means; first, second, third, and fourth shift valve means each being moveable to a spring set position and a pressure controlled position for controlling the engagement of first, second, third, and fourth of said drive establishing means respectively; first fluid passage means in fluid communication with said second relay valve means, said first, second and third shift valve means and said fourth relay valve means for providing pressurized fluid from said pump means through said second relay valve means when said second relay valve means is in the spring set position and providing an exhaust connection when said second relay valve means is in the pressure set position and for moving said fourth relay valve means to said pressure set position; second fluid passage means in fluid communication with said second shift valve means, said first and third relay valve means and the second drive establishing means for directing pressurized fluid in said first passage means to said first and third relay valve means to control movement thereof to said pressure set position, and to the second drive establishing means for controlling engagement thereof when said second shift valve means and second relay valve means are in the spring set position and for permitting exhausting of the pressurized fluid therein to control movement of said first and third relay valve means to the spring set position and for controlling the engagement pressure of the second drive establishing means when said second shift valve is in said pressure controlled position; third passage means in fluid communication with said first shift valve means and said first relay valve means and being in fluid communication with said first passage means when said first shift valve means is in said spring set position and to exhaust when said first shift valve means is in said pressure controlled position for directing fluid pressure to and from said first relay valve means to control movement thereof between the spring set and pressure set positions thereof; fourth passage means in fluid communication with said third shift valve means and said third relay valve means and being in fluid communication with said first passage means when said third shift valve means is in the spring set position and to exhaust when said third shift valve means is in said pressure controlled position for directing fluid pressure to and from said third relay valve means to control movement thereof between the spring set and pressure set positions thereof; said first and second passage means remaining pressurized to prevent a ratio change from second to first and from second to third when said second shift valve means is in said spring set position; said first and third passage means remaining pressurized to prevent a ratio change from second to first when said second shift valve means is in said pressure controlled position and said first shift valve means is in said spring set position; said first and fourth passage means remaining pressurized to prevent a ratio change from second to third when said second shift valve means is in said pressure controlled position and said third shift valve means is in said spring set position; fifth passage means in fluid communication with said third relay valve means, said second, third, aNd fourth shift valve means and said first relay valve means for providing pressurized fluid from said pump means through said third relay valve means when said third relay valve means is in said spring set position and for providing an exhaust connection when said third relay valve means is in the pressure set position, and for moving said first relay valve means to said pressure set position when said third relay valve means is in said spring set position; sixth passage means for providing fluid communication between said third shift valve means and said third drive establishing means to establish engagement thereof, said second relay valve means and said fourth relay valve means; seventh passage means for providing fluid communication between said second shift valve means and said second relay valve means; and eighth passage means for providing fluid communication between said fourth shift valve means and said fourth relay valve means; said fifth and sixth passage means remaining pressurized to prevent a ratio change from third to second and from third to fourth when said third relay valve means and said third shift valve means are in said spring set positions; said fifth and seventh passage means remaining pressurized to prevent a ratio change from third to second when said third relay valve means and said second shift valve means are in said spring set positions and said third shift valve means is in said pressure controlled position; said fifth and eighth passage means remaining pressurized to prevent a ratio change from third to fourth when said third relay valve means and said fourth shift valve means are in said spring positions and said third shift valve means is in said pressure controlled position.

Claim 7

A control for a multi-speed planetary gearing transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing low, intermediate, and high drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; low, intermediate, and high shift valve means each being selectively operable between a spring set and pressure controlled position, for establishing said low, intermediate, and high drive ratios and being moveable to the pressure controlled position for ratio interchange and returning to the spring set position on ratio establishment; relay valve means for each of said low, intermediate, and high shift valve means and each being selectively operable to a spring set position for delivering fluid pressure between said pump means and said shift valve means and a pressure set position for exhausting pressure at said shift valve means; and passage means interconnecting said pump means, said relay valve means, said shift valve means and said drive establishing means for maintaining the intermediate drive ratio established and maintaining the relay valve means for the low and high shift valve means in the pressure set position when the intermediate or high shift valve means do not move to the pressure controlled position during a requested upshift from intermediate to high or the intermedite or low shift means do not move the pressure controlled position during a requested downshift from intermediate to low, for maintaining the low drive ratio established and maintaining the relay valve means for the intermediate and high shift valve means in the pressure set position when the low shift valve means does not move to the pressure controlled position during a requested upshift from low to intermediate, and for maintaining the high drive ratio established and maintaining the relay valve means for the intermediate and low shift valve means in the pressure controlled position when the high shift means does not move to the pressure controlled position during a requested downshift from high to intermediate.

Claim 8

A control for a multi-speed planetary gearing transmission having a plurality of fluid operated selectively engageable drive establishing means for establishing low, intermediate, and high drive ratios in the planetary gearing, said control comprising; pump means for providing a source of fluid pressure; low, intermediate, and high shift valve means each being selectively operable between a spring set and pressure controlled position, for establishing said low, intermediate, and high drive ratios and being moveable to the pressure controlled position for ratio interchange and returning to the spring set position on ratio establishment; relay valve means for each of said low, intermediate, and high shift valve means and each being selectively operable to a spring set position for delivering fluid pressure between said pump means and said shift valve means and a pressure set position for exhausting pressure at said shift valve means; and passage means interconnecting said pump means, said relay valve means, said shift valve means and said drive establishing means for maintaining the intermediate drive ratio established and maintaining the relay valve means for the low and high shift valve means in the pressure set position when the intermediate or high shift valve means do not move to the pressure controlled position during a requested upshift from intermediate to high or the intermedite or low shift means do not move the pressure controlled position during a requested downshift from intermediate to low, for maintaining the low drive ratio established and maintaining the relay valve means for the intermediate and high shift valve means in the pressure set position when the low shift valve means does not move to the pressure controlled position during a requested upshift from low to intermediate, and for maintaining the high drive ratio established and maintaining the relay valve means for the intermediate and low shift valve means in the pressure controlled position when the high shift means does not move to the pressure controlled position during a requested downshift from high to intermediate.