Automatic transmission controls for use in an automotive vehicle

Claim 2

A control mechanism in an automatic transmission for use in an automotive vehicle comprising a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive shaft and driven shaft, and also including a shift valve effective to alternatively establish a low speed power train and a high speed power train in an automatic manner, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, means for providing a first signal force, a value of which is variable with variation of the value of the engine torque signal, means connected to one of said shafts for providing a second signal force, a value of which is variable with variation in value of the shaft speed signal, a first valve means for regulating fluid from said fluid sources in such a manner as to increase a value of said fluid with increase in value of said first signal force under the influence of said first signal force, means including a second valve means for connection between said first valve means and said fluid sources so as to maintain a value of said fluid from the sources to the servomotors at an expected maximum value under the influence of said second signal force during operation of the vehicle within a predetermined speed range, and also for connection of one of said sources to an oil reservoir so as to maintain the value of the fluid at an expected minimum value during operation of the vehicle exceeding the predetermined speed range, and means including a reducing valve for connecting said first valve means and said shift valve and also reducing the pressure of fluid from said fluid sources, said reducing valve being operatively connected to said second valve and effective to modify the amount of said fluid to be reduced so that fluid under reducing pressure to be supplied to one end of said shift valve is proportioned to said first signal force.

Claim 3

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive shaft and driven shaft, and also including a shift valve effective to alternatively establish a low speed power train and a high speed power train in an automatic manner, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a vacuum motor connected to a manifold in the engine for providing a first signal force, a value of which increases with decrease in value of negative pressure in said vacuum motor, means connected to one of said shaft for providing a second signal force, a value of which increases with increase in value of the vehicle driving speed, a regulator valve having a plurality of opposed pressure receiving surfaces and a valve piston in contact with said vacuum motor for regulating the pressure of fluid from at least one of the fluid sources so as to increase its value with decrease in value of the negative pressure, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press a regulator valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press the regulator valve piston in the opposite direction upon application thereof means including an exhaust valve for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of said second signal force during operation of the vehicle within a predetermined speed range and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder during operation of the vehicle exceeding the predetermined speed range, and means including a reducing valve for connecting said regulator valve and shift valve to permit the flow of fluid into one end of said shift valve and also for reducing a value of fluid pressure applied from the fluid sources, said reducing valve being provided with a first pressure receiving surface connected to said first conduit and a second pressure receiving surface connected to said second conduit and being operatively connected to said exhAust valve to modify the amount of said fluid to be reduced so that fluid under reducing pressure to be supplied to one end of said shift valve is proportioned to said first signal force.

Claim 4

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive shaft and driven shaft, and also including a shift valve effective to alternatively establish a low speed power train and a high speed power train in an automatic manner, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a vacuum motor connected to a manifold in the engine for providing a first signal force, a value of which increases with decrease in value of negative pressure in said vacuum motor, means connected to one of said shaft for providing a second signal force, a value of which increases with increase in value of the vehicle driving speed, a regulator valve having a plurality of opposed pressure receiving surfaces and a valve piston in contact with said vacuum motor for regulating the pressure of fluid from at least one of the fluid sources so as to increase its value with decrease in value of the negative pressure, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press a regulator valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press the regulator valve piston in the opposite direction upon application thereof means including an exhaust valve for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of said second signal force during operation of the vehicle within a predetermined speed range and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder during operation of the vehicle exceeding the predetermined speed range, and means including a reducing valve for connecting said regulator valve and shift valve to permit the flow of fluid into one end of said shift valve and also for reducing a value of fluid pressure applied from the fluid sources, said reducing valve being provided with a first pressure receiving surface connected to said first conduit and a second pressure receiving surface connected to said second conduit and being operatively connected to said exhAust valve to modify the amount of said fluid to be reduced so that fluid under reducing pressure to be supplied to one end of said shift valve is proportioned to said first signal force.

Claim 5

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, means responsive to the vehicle driving speed connected to one of said shafts for providing fluid under pressure, a value of said pressure being increased with increase in value of the shaft speed, a regulator valve including a valve piston having a plurality of opposed fluid pressure receiving surfaces and operable in such a manner as to regulate the pressure of fluid supplied from at least one of said fluid sources, a first conduit connecting one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application thereof, and means for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of the fluid from said means responsive to the vehicle driving speed during operation of the vehicle within a predetermined speed range and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder during operation of the vehicle exceeding the predetermined speed range.

Claim 6

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, means responsive to the vehicle driving speed connected to one of said shafts for providing fluid under pressure, a value of said pressure being increased with increase in value of the shaft speed, a regulator valve including a valve piston having a plurality of opposed fluid pressure receiving surfaces and operable in such a manner as to regulate the pressure of fluid supplied from at least one of said fluid sources, a first conduit connecting one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application thereof, and means for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of the fluid from said means responsive to the vehicle driving speed during operation of the vehicle within a predetermined speed range and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder during operation of the vehicle exceeding the predetermined speed range.

Claim 7

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a governor valve connected to one of said shafts for providing a first signal force, a value of which being increased with increase in value of the shaft speed, means for providing a second signal force, a value of which being increased with increase in value of the required torque for said drive shaft, a regulator valve having a valve piston therein formed with a plurality of opposed pressure receiving surfaces for regulating the pressure of fluid from at least one of the fluid sources, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application thereof, and an exhaust valve for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of the first signal force and second signal force when the values of said signal forces are respectively within predetermined ranges and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder when they are respectively exceeding the predetermined ranges, whereby Fluid under pressure to be supplied to said servomotors is controlled in value from the expected maximum to the expected minimum or from the expected minimum to the expected maximum in accordance with a value of the required torque for said drive shaft and the speed of said shafts.

Claim 8

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a governor valve connected to one of said shafts for providing a first signal force, a value of which being increased with increase in value of the shaft speed, means for providing a second signal force, a value of which being increased with increase in value of the required torque for said drive shaft, a regulator valve having a valve piston therein formed with a plurality of opposed pressure receiving surfaces for regulating the pressure of fluid from at least one of the fluid sources, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application thereof, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application thereof, and an exhaust valve for connecting between said first and second conduits so as to maintain a value of the fluid from said sources to said hydraulically operable servomotors at an expected maximum value under the influence of the first signal force and second signal force when the values of said signal forces are respectively within predetermined ranges and also disconnecting therebetween and connecting said second conduit to a reservoir so as to maintain the value of the fluid at an expected minimum value thereunder when they are respectively exceeding the predetermined ranges, whereby Fluid under pressure to be supplied to said servomotors is controlled in value from the expected maximum to the expected minimum or from the expected minimum to the expected maximum in accordance with a value of the required torque for said drive shaft and the speed of said shafts.

Claim 9

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a governor valve connected to one of said shafts for providing a first signal force, a value of which being increased with increase in value of the speed shaft, means for providing a second signal force, a value of which being increased with increase in value of the required torque for said drive shaft, a regulator valve having a valve piston therein formed with a plurality of opposed pressure receiving surfaces for regulating the pressure of fluid from at least one of the fluid sources, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application of the fluid thereto, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application of the fluid thereto, an exhaust valve for modifying a value of fluid to be supplied from the fluid sources to the hydraulically operable servomotors with increase in value of the first signal force, said exhaust valve including a valve piston having two ends opposed to each other slidable therein between a first position and a second position in such a manner that, when said valve piston is in the first position, said first conduit and second conduit are communicated to each other and when said valve piston is in the second position, said second conduit is connected to a reservoir with disconnection between the first conduit and the second conduit so as to maintain a value of fluid less than a value thereof in the first position, and at this time the first signal force being applied on one end of the valve piston and the second signal force being applied on the other end thereof so as to change a shift point of a level of fluid pressure.

Claim 10

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, at least two fluid sources for supplying fluid under pressure to said hydraulically operable servomotors, a governor valve connected to one of said shafts for providing a first signal force, a value of which being increased with increase in value of the speed shaft, means for providing a second signal force, a value of which being increased with increase in value of the required torque for said drive shaft, a regulator valve having a valve piston therein formed with a plurality of opposed pressure receiving surfaces for regulating the pressure of fluid from at least one of the fluid sources, a first conduit connecting between one of said fluid sources and one of the pressure receiving surfaces of said regulator valve to permit fluid from said source to press said valve piston in one direction upon application of the fluid thereto, a second conduit connecting between the rest of said fluid sources and another one of the pressure receiving surfaces of the regulator valve to permit fluid from said source to press the valve piston in the opposite direction upon application of the fluid thereto, an exhaust valve for modifying a value of fluid to be supplied from the fluid sources to the hydraulically operable servomotors with increase in value of the first signal force, said exhaust valve including a valve piston having two ends opposed to each other slidable therein between a first position and a second position in such a manner that, when said valve piston is in the first position, said first conduit and second conduit are communicated to each other and when said valve piston is in the second position, said second conduit is connected to a reservoir with disconnection between the first conduit and the second conduit so as to maintain a value of fluid less than a value thereof in the first position, and at this time the first signal force being applied on one end of the valve piston and the second signal force being applied on the other end thereof so as to change a shift point of a level of fluid pressure.

Claim 11

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, means for providing a first signal force, a value of which being variable in accordance with a value of a first signal, means for providing a second signal force, a value of which being variable in accordance with a value of a second signal, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors, a regulator valve for regulating the pressure of fluid from said fluid source under the influence of said first and second signal forces, a reducing valve for providing a second fluid under pressure proportioned merely to a value of the second signal force by modifying in accordance with variation of a value of the first signal force a reduced amount of the fluid regulated by said regulator valve, and a shift valve for automatically directing fluid from said fluid source to said servomotors, said shift valve including a valve piston having a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shiFt valve is to be operated with variation of respective first and second signals.

Claim 12

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shafts, means for providing a first signal force, a value of which being variable in accordance with a value of a first signal, means for providing a second signal force, a value of which being variable in accordance with a value of a second signal, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors, a regulator valve for regulating the pressure of fluid from said fluid source under the influence of said first and second signal forces, a reducing valve for providing a second fluid under pressure proportioned merely to a value of the second signal force by modifying in accordance with variation of a value of the first signal force a reduced amount of the fluid regulated by said regulator valve, and a shift valve for automatically directing fluid from said fluid source to said servomotors, said shift valve including a valve piston having a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shiFt valve is to be operated with variation of respective first and second signals.

Claim 13

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive shafts, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means for providing a second signal force, a value of which being varied in accordance with a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors, a regulator valve for regulating the pressure of fluid from said fluid source under the influence of said first and second signal forces so as to render a value thereof to vary with variation of respective values of said first and second signal forces, a reducing valve for providing a second fluid under pressure proportioned merely to a value of the second signal force by modifying in accordance with variation of a value of the first signal force a reduced amount of the fluid regulated by said regulator valve, and shift valve for automatically directing fluid from said fluid source to said servomotors, said shift valve including a valve piston having a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 14

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive shafts, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means for providing a second signal force, a value of which being varied in accordance with a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors, a regulator valve for regulating the pressure of fluid from said fluid source under the influence of said first and second signal forces so as to render a value thereof to vary with variation of respective values of said first and second signal forces, a reducing valve for providing a second fluid under pressure proportioned merely to a value of the second signal force by modifying in accordance with variation of a value of the first signal force a reduced amount of the fluid regulated by said regulator valve, and shift valve for automatically directing fluid from said fluid source to said servomotors, said shift valve including a valve piston having a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 15

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors, for establishing a power train between said drive and driven shafts, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means for providing a second signal force, a value of which being varied in accordance with variation of a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors therefrom, a regulator drive including a valve piston which is capable of being operatively connected to said second mentioned means, said third mentioned means, and said fluid source respectively for modifying a value of fluid from said fluid source in accordance with variation of respective values of the first and second signal forces, said valve piston being provided with a first pressure receiving surface to which the fluid from said fluid source is supplied to press said valve piston in one direction and a second pressure receiving surface to which the first signal force is supplied to press the valve piston in the opposite direction, a reducing valve having a valve piston therein and connected to said regulator valve so as to provide a second fluid under pressure by reducing said fluid under reduced pressure, a third pressure receiving surface provided in the valve piston of the reducing valve and connected to said first mentioned means so as to modify an amount of reduction of said fluid under regulated pressure in accordance with variation of a value of said first signal force, to prevent a value of said second fluid under pressure from being varied with variation of a value of the first signal force, and to vary its value in response to variation of a value of the second signal force, and a shift valve for automatically directing fluid under regulated pressure from said fluid source to said servomotors, said shift valve including a valve piston provided with a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 16

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors, for establishing a power train between said drive and driven shafts, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means for providing a second signal force, a value of which being varied in accordance with variation of a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said hydraulically operable servomotors therefrom, a regulator drive including a valve piston which is capable of being operatively connected to said second mentioned means, said third mentioned means, and said fluid source respectively for modifying a value of fluid from said fluid source in accordance with variation of respective values of the first and second signal forces, said valve piston being provided with a first pressure receiving surface to which the fluid from said fluid source is supplied to press said valve piston in one direction and a second pressure receiving surface to which the first signal force is supplied to press the valve piston in the opposite direction, a reducing valve having a valve piston therein and connected to said regulator valve so as to provide a second fluid under pressure by reducing said fluid under reduced pressure, a third pressure receiving surface provided in the valve piston of the reducing valve and connected to said first mentioned means so as to modify an amount of reduction of said fluid under regulated pressure in accordance with variation of a value of said first signal force, to prevent a value of said second fluid under pressure from being varied with variation of a value of the first signal force, and to vary its value in response to variation of a value of the second signal force, and a shift valve for automatically directing fluid under regulated pressure from said fluid source to said servomotors, said shift valve including a valve piston provided with a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which a second fluid under pressure is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 17

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shaft, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a second signal force, a value of which being varied in accordance with variation of a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said servomotors, a regulator valve hydraulically connected to said second mentioned means and mechanically connected to said third mentioned means and having a valve piston operable so as to modify a value of fluid under pressure from said fluid source in accordance with variation of respective values of the first signal force and the second signal force, a first pressure receiving surface on said valve piston for pressing said valve piston in one direction upon application of the first signal force thereto, a reducing valve having a valve piston therein and connected to said regulator valve for providing a second fluid under pressure by reducing a value of said fluid under regulated pressure, a second pressure receiving surface on said valve piston of said reducing valve and connected to said second mentioned means so as to modify an amount of reduction of said fluid under regulated pressure in accordance with variation of a value of said first signal force, to prevent a value of said second fluid from being varied with variation of a value of the first signal force, and to vary its value in response to variation of a value of the second signal force, and a shift valve for automatically directing said fluid under regulated pressure from the fluid source to the servomotors, said shift valve including a valve piston provided with a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which the second fluid is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 18

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including hydraulically operable servomotors for establishing a power train between said drive and driven shaft, means for providing a first signal force, a value of which being varied in accordance with a value of the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a second signal force, a value of which being varied in accordance with variation of a value of the required torque for said drive shaft, a fluid source for supplying fluid under pressure to said servomotors, a regulator valve hydraulically connected to said second mentioned means and mechanically connected to said third mentioned means and having a valve piston operable so as to modify a value of fluid under pressure from said fluid source in accordance with variation of respective values of the first signal force and the second signal force, a first pressure receiving surface on said valve piston for pressing said valve piston in one direction upon application of the first signal force thereto, a reducing valve having a valve piston therein and connected to said regulator valve for providing a second fluid under pressure by reducing a value of said fluid under regulated pressure, a second pressure receiving surface on said valve piston of said reducing valve and connected to said second mentioned means so as to modify an amount of reduction of said fluid under regulated pressure in accordance with variation of a value of said first signal force, to prevent a value of said second fluid from being varied with variation of a value of the first signal force, and to vary its value in response to variation of a value of the second signal force, and a shift valve for automatically directing said fluid under regulated pressure from the fluid source to the servomotors, said shift valve including a valve piston provided with a first end to which the first signal force is applied so as to press said valve piston in one direction and a second end to which the second fluid is applied so as to press said valve piston in the opposite direction, whereby said shift valve is to be operated with variation of respective values of the shaft speed and required torque for said shaft.

Claim 19

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including a servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve having a valve piston therein for automatically directing said first fluid under pressure from the fluid source to said servomotors, means hydraulically connected to one end of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation of a value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, means for reducing the amount of reduction of said fourth fluid in accordance with increase of a value of the third fluid exceeding the predetermined value, and means for connecting said second valve to said shift valve so as to press said vAlve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 20

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including a servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve having a valve piston therein for automatically directing said first fluid under pressure from the fluid source to said servomotors, means hydraulically connected to one end of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation of a value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, means for reducing the amount of reduction of said fourth fluid in accordance with increase of a value of the third fluid exceeding the predetermined value, and means for connecting said second valve to said shift valve so as to press said vAlve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 21

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve including a valve piston therein for automatically directing said first fluid from the fluid source to the servomotors, means hydraulically connected to one of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation in value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, said second valve including a valve element urged in one direction by a spring, means for controlling the biasing of said valve element to reduce an amount of reduction of said fourth fluid in accordance with an increase of the third fluid when a value of said third fluid exceeds the predetermined value, and means for connecting said second valve to said shift valve so as to press said valve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 22

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve including a valve piston therein for automatically directing said first fluid from the fluid source to the servomotors, means hydraulically connected to one of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation in value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, said second valve including a valve element urged in one direction by a spring, means for controlling the biasing of said valve element to reduce an amount of reduction of said fourth fluid in accordance with an increase of the third fluid when a value of said third fluid exceeds the predetermined value, and means for connecting said second valve to said shift valve so as to press said valve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 23

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve including a valve piston therein for automatically directing said first fluid from the fluid source to said servomotors, means hydraulically connected to one end of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation in value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, said second valve including a valve element urged in one direction by a spring, means including a plug having a pressure receiving surface and connected to said second valve so as to press said plug in one direction against the resilient force of the spring, said plug being operable to reduce the biasing force of said valve element while increasing an amount of compression of said second spring in accordance with increase in value of the third fluid under pressure when a value of the fourth fluid under pressure acting on said pressure receiving surface exceeds the predetermined value, whereby, when a value of the third fluid under pressure exceeds the predetermined value, the fourth fluid under pressure is reduced with respect to its difference to that of the third fluid in accordance with an increase in value of the third fluid, and means for connecting said second valve to said shift valve so as to press said valve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 24

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, means including servomotors for establishing a power train between said drive and driven shafts, a fluid source for supplying a first fluid under pressure to said servomotors, a shift valve including a valve piston therein for automatically directing said first fluid from the fluid source to said servomotors, means hydraulically connected to one end of said valve piston for providing a second fluid under pressure so as to press said valve piston in one direction, a value of said second fluid being variable in accordance with the speed of one of said drive and driven shafts, means connected to an intake manifold in the engine for providing a third fluid under pressure, a value of which being varied with variation in value of negative pressure therein, a second valve for providing a fourth fluid under pressure by reducing a value of said third fluid under pressure in a predetermined value, said second valve including a valve element urged in one direction by a spring, means including a plug having a pressure receiving surface and connected to said second valve so as to press said plug in one direction against the resilient force of the spring, said plug being operable to reduce the biasing force of said valve element while increasing an amount of compression of said second spring in accordance with increase in value of the third fluid under pressure when a value of the fourth fluid under pressure acting on said pressure receiving surface exceeds the predetermined value, whereby, when a value of the third fluid under pressure exceeds the predetermined value, the fourth fluid under pressure is reduced with respect to its difference to that of the third fluid in accordance with an increase in value of the third fluid, and means for connecting said second valve to said shift valve so as to press said valve piston of said shift valve in the opposite direction by said fourth fluid under pressure.

Claim 25

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, a fluid source, means including a plurality of servomotors for establishing a plurality of power trains between said drive and driven sHafts in such a manner as to establish a first power train therebetween by means of a first servomotor and second servomotor and also to establish a second power train therebetween by means of a third servomotor and said second servomotor, a manual valve having a valve piston movable to selectively position in a first position in which said first power train can be established and in a second position in which said second power train can be established, a first conduit for connecting between the fluid source and said second servomotor when said manual valve piston is in the first position and also connecting between said second servomotor and an oil reservoir when said manual valve piston is in the second position, a second conduit for connecting between said second servomotor and the fluid source when the manual valve piston is in the first position and the second position, said second conduit having a first restriction for restricting the flow of fluid to the second servomotor, and a branch conduit for connecting said first conduit to said second conduit between said first restriction and said second servomotor, said branch conduit having a second restriction for discharging a portion of the fluid flowing to said second servomotor to said reservoir when the manual valve piston is in the second position, whereby a value of fluid to be supplied to the second servomotor when said manual valve piston is in the first position is greater than that when in the second position.

Claim 26

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, a fluid source, means including a plurality of servomotors for establishing a plurality of power trains between said drive and driven sHafts in such a manner as to establish a first power train therebetween by means of a first servomotor and second servomotor and also to establish a second power train therebetween by means of a third servomotor and said second servomotor, a manual valve having a valve piston movable to selectively position in a first position in which said first power train can be established and in a second position in which said second power train can be established, a first conduit for connecting between the fluid source and said second servomotor when said manual valve piston is in the first position and also connecting between said second servomotor and an oil reservoir when said manual valve piston is in the second position, a second conduit for connecting between said second servomotor and the fluid source when the manual valve piston is in the first position and the second position, said second conduit having a first restriction for restricting the flow of fluid to the second servomotor, and a branch conduit for connecting said first conduit to said second conduit between said first restriction and said second servomotor, said branch conduit having a second restriction for discharging a portion of the fluid flowing to said second servomotor to said reservoir when the manual valve piston is in the second position, whereby a value of fluid to be supplied to the second servomotor when said manual valve piston is in the first position is greater than that when in the second position.

Claim 27

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, a fluid source, means including a plurality of servomotors for establishing a plurality of power trains between said drive and driven shafts in such a manner as to establish a reverse drive power train therebetween by means of a first servomotor and second servomotor and also to establish a low speed forward drive power train therebetween by means of a third servomotor and said second servomotor, a manual valve having a valve piston movable to selectively position in a first position in which said reverse drive power train can be established and in a second position in which said low speed forward drive power train can be established, a first conduit for connecting between the fluid source and the second servomotor when said manual valve piston is in the first position and also connecting between said second servomotor to an oil reservoir when said manual valve piston is in the second position, a second conduit for connecting between the second servomotor and the fluid source when the manual valve piston is in the first position and the second position, said conduit having a first restriction for restricting the flow of fluid to the second servomotor, and a branch conduit for connecting said first conduit to said second conduit between said first restriction and said second servomotor, said branch conduit having a second restriction for discharging a portion of the fluid flowing to said second servomotor to said reservoir when the manual valve piston is in the second position, whereby a value of fluid to be supplied to the second servomotor when said manual valve piston is in the first position is greater than that when in the second position.

Claim 28

A control mechanism in an automatic transmission for use in an automotive vehicle comprising: a drive shaft, a driven shaft, a fluid source, means including a plurality of servomotors for establishing a plurality of power trains between said drive and driven shafts in such a manner as to establish a reverse drive power train therebetween by means of a first servomotor and second servomotor and also to establish a low speed forward drive power train therebetween by means of a third servomotor and said second servomotor, a manual valve having a valve piston movable to selectively position in a first position in which said reverse drive power train can be established and in a second position in which said low speed forward drive power train can be established, a first conduit for connecting between the fluid source and the second servomotor when said manual valve piston is in the first position and also connecting between said second servomotor to an oil reservoir when said manual valve piston is in the second position, a second conduit for connecting between the second servomotor and the fluid source when the manual valve piston is in the first position and the second position, said conduit having a first restriction for restricting the flow of fluid to the second servomotor, and a branch conduit for connecting said first conduit to said second conduit between said first restriction and said second servomotor, said branch conduit having a second restriction for discharging a portion of the fluid flowing to said second servomotor to said reservoir when the manual valve piston is in the second position, whereby a value of fluid to be supplied to the second servomotor when said manual valve piston is in the first position is greater than that when in the second position.