Step-ratio transmissions with fluid operated synchronizing brake

Claim 2

In a transmission control for use with a step-ratio transmission having an input shaft and a synchronizer brake means selectively engageable for controlling the speed of said input shaft; a source of fluid pressure; a shift valve means in fluid communication with said source and movable to a downshift and an upshift position; synchronizer brake control means including input driven governor means for providing a pressure proportional to the speed of said input shaft, governor accumulator means, a synchronizing valve having a governor chamber and an accumulator chamber and being movable to an engage position and an exhaust position, a synchronizer control valve having a normally open position connecting both said governor means and said governor accumulator means with both of said chambers and being movable in response to said shift valve means to a synchronizing position connecting said governor means to said governor chamber and said governor accumulator means to said accumulator chamber to move said synchronizing valve to said engage position to engage said synchronizer brake means to decrease the speed of said input shaft.

Claim 3

In a transmission control for use with a step-ratio transmission having an input shaft and a synchronizer brake means selectively engageable for controlling the speed of said input shaft; a source of fluid pressure; shift valve means in fluid communication with said source and movable to a downshift and an upshift position; a synchronizer relay valve means having A normally closed position and being movable to an open position in response to movement of said shift valve means to said upshift position; synchronizer brake control means operatively connected to said synchronizer relay valve means including input driven governor means for providing a pressure proportional to the speed of said input shaft, governor accumulator means, a synchronizer regulating valve having a governor chamber and an accumulator chamber and being movable to an engage position and an exhaust position, and a synchronizer control valve having a normally open position connecting both said governor means and said governor accumulator means with both of said chambers and being movable in response to opening of said synchronizer relay valve means to a synchronizing position connecting said governor means to said governor chamber and said governor accumulator means to said accumulator chamber to move said synchronizer regulating valve to said engage position to engage said synchronizer brake means to decrease the speed of said input shaft.

Claim 4

In a transmission control for use with a step-ratio transmission having an input shaft and a synchronizer brake means selectively engageable for controlling the speed of said input shaft; a source of fluid pressure; shift valve means in fluid communication with said source and movable to a downshift and an upshift position; a synchronizer relay valve means having A normally closed position and being movable to an open position in response to movement of said shift valve means to said upshift position; synchronizer brake control means operatively connected to said synchronizer relay valve means including input driven governor means for providing a pressure proportional to the speed of said input shaft, governor accumulator means, a synchronizer regulating valve having a governor chamber and an accumulator chamber and being movable to an engage position and an exhaust position, and a synchronizer control valve having a normally open position connecting both said governor means and said governor accumulator means with both of said chambers and being movable in response to opening of said synchronizer relay valve means to a synchronizing position connecting said governor means to said governor chamber and said governor accumulator means to said accumulator chamber to move said synchronizer regulating valve to said engage position to engage said synchronizer brake means to decrease the speed of said input shaft.

Claim 5

A transmission control for use with a change-ratio transmission, having an input shaft, an output shaft means for establishing a pair of drive ratios between said shafts with a step ratio between the drive ratios, including synchronizer brake means being operable at times for controlling the speed of said input shaft; a source of fluid pressure; shift valve means operatively connected to said transmission and being movable to a downshift position for establishing one drive ratio and to an upshift position for establishing the other drive ratio; upshift relay valve means operatively connected with and responsive to said shift valve means; synchronizer brake control valve means including synchronizing valve means movable for engaging and disengaging said synchronizer brake means having a governor chamber and an accumulator chamber, input governor means for providing a governor pressure signal proportional to the speed of the input shaft, accumulator means for establishing a fixed pressure signal relative to the governor pressure signal, synchronizer control valve means operatively connected to said upshift relay valve means and being movable to an open position to interconnect both of said chambers, said governor means and said accumulator means and to an upshift synchronizing position to connect said governor chamber with the governor pressure signal and the accumulator chamber with the fixed pressure signal to move said synchronizing valve means to engage said synchronizer brake.

Claim 6

A transmission control for use with a change-ratio transmission, having an input shaft, an output shaft means for establishing a pair of drive ratios between said shafts with a step ratio between the drive ratios, including synchronizer brake means being operable at times for controlling the speed of said input shaft; a source of fluid pressure; shift valve means operatively connected to said transmission and being movable to a downshift position for establishing one drive ratio and to an upshift position for establishing the other drive ratio; upshift relay valve means operatively connected with and responsive to said shift valve means; synchronizer brake control valve means including synchronizing valve means movable for engaging and disengaging said synchronizer brake means having a governor chamber and an accumulator chamber, input governor means for providing a governor pressure signal proportional to the speed of the input shaft, accumulator means for establishing a fixed pressure signal relative to the governor pressure signal, synchronizer control valve means operatively connected to said upshift relay valve means and being movable to an open position to interconnect both of said chambers, said governor means and said accumulator means and to an upshift synchronizing position to connect said governor chamber with the governor pressure signal and the accumulator chamber with the fixed pressure signal to move said synchronizing valve means to engage said synchronizer brake.

Claim 7

In a transmission and control an input shaft; and output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing a plurality of gear ratios in said step-ratio gearing means with a substantially equal geometric step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, a pair of shift valve means shiftable for controlling the operation of said ratio engaging means, synchronizer brake control means for controlling the operation of said synchronizer brake means including a synchronizing valve having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect said input governor means with said accumulator means and both of said chambers and to an upshift position to connect said input governoR means to said governor chamber only and said accumulator means to said accumulator chamber, and relay valves associated with and operatively connected between said shift valves and said pressure control valve, whereby said synchronizer brake is engaged when either of said shift valves is shifted to change gear ratios and to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shafts substantially equal to said step ratio while the gear changed is occurring.

Claim 8

In a transmission and control an input shaft; and output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing a plurality of gear ratios in said step-ratio gearing means with a substantially equal geometric step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, a pair of shift valve means shiftable for controlling the operation of said ratio engaging means, synchronizer brake control means for controlling the operation of said synchronizer brake means including a synchronizing valve having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect said input governor means with said accumulator means and both of said chambers and to an upshift position to connect said input governoR means to said governor chamber only and said accumulator means to said accumulator chamber, and relay valves associated with and operatively connected between said shift valves and said pressure control valve, whereby said synchronizer brake is engaged when either of said shift valves is shifted to change gear ratios and to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shafts substantially equal to said step ratio while the gear changed is occurring.

Claim 9

In a transmission control for use with an equal step-ratio transmission having an input shaft and a synchronizer brake means selectively engageable for controlling the speed of said input shaft; and output shaft and planetary gear means between said shafts, a source of fluid pressure; a shift valve in fluid communication with said source and movable to a downshift and an upshift position; a synchronizer relay valve having a normally closed position and being movable to an open position in response to movement of said shift valve to said upshift position; synchronizer brake control means including input-driven governor means for providing a pressure proportional to the speed of said input shaft, governor accumulator means, a synchronizer valve having a governor chamber and an accumulator chamber with the ratio of said chambers being proportional to said step ratio and being movable to an engage position and an exhaust position, a synchronizer control valve having a normally open position connecting both said governor means and said governor accumulator means with both of said chambers and having a synchronizing position connecting said governor means to said governor chamber and said governor accumulator means to said accumulator chamber to move said synchronizing valve to said engage position to engage said synchronizer brake means to decrease the speed of said input shaft to establish a speed ratio between said input and output shafts equal to said step ratio.

Claim 10

In a transmission control for use with an equal step-ratio transmission having an input shaft and a synchronizer brake means selectively engageable for controlling the speed of said input shaft; and output shaft and planetary gear means between said shafts, a source of fluid pressure; a shift valve in fluid communication with said source and movable to a downshift and an upshift position; a synchronizer relay valve having a normally closed position and being movable to an open position in response to movement of said shift valve to said upshift position; synchronizer brake control means including input-driven governor means for providing a pressure proportional to the speed of said input shaft, governor accumulator means, a synchronizer valve having a governor chamber and an accumulator chamber with the ratio of said chambers being proportional to said step ratio and being movable to an engage position and an exhaust position, a synchronizer control valve having a normally open position connecting both said governor means and said governor accumulator means with both of said chambers and having a synchronizing position connecting said governor means to said governor chamber and said governor accumulator means to said accumulator chamber to move said synchronizing valve to said engage position to engage said synchronizer brake means to decrease the speed of said input shaft to establish a speed ratio between said input and output shafts equal to said step ratio.

Claim 11

A transmission control for use with a change ratio transmission, having an input shaft, an output shaft means for establishing a pair of drive ratios between said shafts with a step ratio between the drive ratios, including synchronizer brake means being operable at times for controlling the speed of said input shaft; a source of fluid pressure; shift valve means operatively connected to said transmission and being movable to a downshift position for establishing one drive ratio and to an upshift position for establishing the other drive ratio; upshift relay valve means operatively connected with and responsive to said shift valve means; downshift relay valve means operatively connected with and responsive to said shift valve means; synchronizer brake control valve means including synchronizing valve means movable for engaging and disengaging said synchronizer brake means having a governor chamber and an accumulator chamber with said chambers having an area ratio proportional to said step ratio, input governor means for providing a governor pressure signal proportional to the speed of the input shaft, accumulator means for establishing a fixed pressure signal relative to the governor pressure signal, synchronizer control valve means operatively connected to said upshift relay valve means and said downshift valve means and being movable to an open position to interconnect both of said chambers with said governor means and said accumulator means, to an upshift synchronizing position to connect said governor chamber with the governor pressure signal and the accumulator chamber with the fixed pressure signal to move said synchronizing valve means to engage said synchronizer brake until the speed ratio of said input and output shafts equals said step ratio, and to a downshift synchronizing position to connect said accumulator chamber with the governor pressure signal and the governor chamber with the fixed pressure signal to move said synchronizing valve meAns to engage said synchronizer brake when the speed ratio of said shafts equals said step ratio.

Claim 12

A transmission control for use with a change ratio transmission, having an input shaft, an output shaft means for establishing a pair of drive ratios between said shafts with a step ratio between the drive ratios, including synchronizer brake means being operable at times for controlling the speed of said input shaft; a source of fluid pressure; shift valve means operatively connected to said transmission and being movable to a downshift position for establishing one drive ratio and to an upshift position for establishing the other drive ratio; upshift relay valve means operatively connected with and responsive to said shift valve means; downshift relay valve means operatively connected with and responsive to said shift valve means; synchronizer brake control valve means including synchronizing valve means movable for engaging and disengaging said synchronizer brake means having a governor chamber and an accumulator chamber with said chambers having an area ratio proportional to said step ratio, input governor means for providing a governor pressure signal proportional to the speed of the input shaft, accumulator means for establishing a fixed pressure signal relative to the governor pressure signal, synchronizer control valve means operatively connected to said upshift relay valve means and said downshift valve means and being movable to an open position to interconnect both of said chambers with said governor means and said accumulator means, to an upshift synchronizing position to connect said governor chamber with the governor pressure signal and the accumulator chamber with the fixed pressure signal to move said synchronizing valve means to engage said synchronizer brake until the speed ratio of said input and output shafts equals said step ratio, and to a downshift synchronizing position to connect said accumulator chamber with the governor pressure signal and the governor chamber with the fixed pressure signal to move said synchronizing valve meAns to engage said synchronizer brake when the speed ratio of said shafts equals said step ratio.

Claim 13

In a transmission and control an input shaft; an output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing three gear ratios in said step-ratio gearing means with an equal geometric step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, first shift valve means for controlling ratio change between the first and second of the gear ratios, second shift valve means for controlling ratio change between the second and third of the gear ratios, synchronizer brake control means for controlling the operation of said synchronizer brake means during a ratio change including a synchronizing valve having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect said input governor means with said accumulator means and both of said chambers, to an upshift position to connect said input governors means to said governor chamber only and said accumulator means to said accumulator chamber, and to a downshift position to connect said governor means to said accumulator chamber and said accumulator means to said governor chamber, and relay valves associated with and operatively connected between said shift valves and said pressure control valve, whereby said synchronizer brake is engaged when either of said shift valves is shifted to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shafts substantially equal to said step ratio.

Claim 14

In a transmission and control an input shaft; an output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing three gear ratios in said step-ratio gearing means with an equal geometric step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, first shift valve means for controlling ratio change between the first and second of the gear ratios, second shift valve means for controlling ratio change between the second and third of the gear ratios, synchronizer brake control means for controlling the operation of said synchronizer brake means during a ratio change including a synchronizing valve having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect said input governor means with said accumulator means and both of said chambers, to an upshift position to connect said input governors means to said governor chamber only and said accumulator means to said accumulator chamber, and to a downshift position to connect said governor means to said accumulator chamber and said accumulator means to said governor chamber, and relay valves associated with and operatively connected between said shift valves and said pressure control valve, whereby said synchronizer brake is engaged when either of said shift valves is shifted to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shafts substantially equal to said step ratio.

Claim 15

In a transmission and control an input shaft; an output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing three gear ratios in said step-ratio gearing means with an equal step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, a pair of shift valve means shiftable for controlling the operation of said ratio engaging means, synchronizer brake control means for controlling the operation of said synchronizer brake means including a synchronizing valve operatively connected with said synchronizer brake means and having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect input governor means with said accumulator means and both of said chambers and to an upshift position to connect said input governor means to said governor chamber only and said accumulator means to said accumulator chamber, and relay valves associated with an operatively connected between said shift valves and said pressure control valve, whereby said synchronizeR brake is engaged when either of said shift valves is shifted to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shaft substantially equal to said step ratio and said ratio engaging means operative to establish the first and second gear ratios each having check valve means operatively connected with said synchronizer brake means for maintaining said first ratio engaged during a shift from first to second ratio until said synchronizer brake is engaged and for maintaining said second ratio engaged during a shift from second to third ratio until said synchronizer brake is engaged.

Claim 16

In a transmission and control an input shaft; an output shaft; step-ratio gearing means operatively connected between said input and output shafts; selectively operable ratio engaging means operatively connected with said step-ratio gearing means for establishing three gear ratios in said step-ratio gearing means with an equal step ratio between the gear ratios; selectively operable synchronizer brake means operatively connected with said input shaft for controlling the speed of the input shaft to establish a speed ratio between said input and output shafts substantially equal to the step ratio; and control means for controlling the operation of said ratio engaging means and said synchronizer brake means including input governor means operatively connected to said input shaft for generating a governor signal proportional to the speed of the input shaft, accumulator means, a pair of shift valve means shiftable for controlling the operation of said ratio engaging means, synchronizer brake control means for controlling the operation of said synchronizer brake means including a synchronizing valve operatively connected with said synchronizer brake means and having a governor chamber and an accumulator chamber with a diameter ratio between said chambers equal to said step ratio, a pressure control valve movable to an open position to connect input governor means with said accumulator means and both of said chambers and to an upshift position to connect said input governor means to said governor chamber only and said accumulator means to said accumulator chamber, and relay valves associated with an operatively connected between said shift valves and said pressure control valve, whereby said synchronizeR brake is engaged when either of said shift valves is shifted to operate said relay valves and said pressure control valve to activate said synchronizing valve to establish the speed ratio between said input and output shaft substantially equal to said step ratio and said ratio engaging means operative to establish the first and second gear ratios each having check valve means operatively connected with said synchronizer brake means for maintaining said first ratio engaged during a shift from first to second ratio until said synchronizer brake is engaged and for maintaining said second ratio engaged during a shift from second to third ratio until said synchronizer brake is engaged.

Claim 17

In a transmission, input means, output means, multiratio gear means operatively connecting said input and said output means and having first drive means operative to provide a low speed ratio between said input and said output means and second drive means having engaging means for disestablishing and establishing a second higher speed ratio between said input and said output means, synchronizer brake means having brake means operatively connected to said input means and actuator means for engaging and disengaging said brake means, input governor means providing a governor signal proportional to transmission input speed, shift control means movable from a first low-speed position to a second high-speed position and operative in said second position to provide a shift command signal operatively connected to said engaging means and said actuator means to move said actuator means from the disengaged to the engaged position, and reference signal means operatively connected to said actuator means and said input governor means and operative in response to said shift command signal to provide a continuous reference signal having a substantially constant value based on the value of said input governor signal when said shift command signal is received, said actuator means being responsive to said reference signal and said input governor signal to engage the synchronizer brake sufficient to control the speed of said input means to establish the speed ratio between said input and output means substantially equal to the step ratio between said low speed ratio and said second higher speed ratio for synchronizing the shift change.

Claim 18

In a transmission, input means, output means, multiratio gear means operatively connecting said input and said output means and having first drive means operative to provide a low speed ratio between said input and said output means and second drive means having engaging means for disestablishing and establishing a second higher speed ratio between said input and said output means, synchronizer brake means having brake means operatively connected to said input means and actuator means for engaging and disengaging said brake means, input governor means providing a governor signal proportional to transmission input speed, shift control means movable from a first low-speed position to a second high-speed position and operative in said second position to provide a shift command signal operatively connected to said engaging means and said actuator means to move said actuator means from the disengaged to the engaged position, and reference signal means operatively connected to said actuator means and said input governor means and operative in response to said shift command signal to provide a continuous reference signal having a substantially constant value based on the value of said input governor signal when said shift command signal is received, said actuator means being responsive to said reference signal and said input governor signal to engage the synchronizer brake sufficient to control the speed of said input means to establish the speed ratio between said input and output means substantially equal to the step ratio between said low speed ratio and said second higher speed ratio for synchronizing the shift change.