Fluid drive transmission employing lockup clutch

Power shifted composite drive to transmit multiple speeds from the engine shaft of an engine, comprising:

• a speed transmission (20) having an input shaft, an output shaft, a plural intervening mechanically synchronized gear ratio trains selectively connected to the output shaft, first means (18) providing a fluid coupling of the engine shaft to said input shaft, and second means (29,31) coupling said input shaft to said mechanically synchronized, selective gear ratio trains;
• a synchronized gear ratio range transmission (24) which is step shiftable to provide at least three ranges of speed and powered by a range transmission driving shaft (110) to be driven by said speed transmission output shaft;
• third means (22) comprising a master clutch coupling said output shaft to the driving shaft of the range transmission to be driven thereby;
• means (146, 112, 72, 138, 206, 150, 90, 74) to disengage the just said third coupling to free the range transmission from the inertia of the speed transmission for reduced wear of the synchronized range transmission during shifts between gear ratios, and to disengage the second coupling to free the speed transmission from the inertia of the engine for reduced wear of the mechanical synchronizers therein during changes of the gear ratio train selected;
• said first coupling comprising a high-slip fluid drive and power shift lockup clutch (38) device to transmit engine speed to said speed transmission input shaft for two speed ratio modes of driving same from the engine, and said second coupling comprising selectable torque amplifier power shift clutches to transmit input shaft speed to the selected mechanically synchronized gear ratio train for two speed ratio modes of driving same from the input shaft, and including a power shift high speed clutch means for power shifting to a higher speed;
• power shift operating means (149,59) to operate said master clutch for coupling the output and driving shafts, and to operate said power shift lockup clutch for power shifting to a higher speed, and to operate said power shift high speed clutch means for power shifting to a higher speed, all to complete a clutched together power path from engine through the range transmission;
• and
• activatable means included in said operating means which, as a tight sequence when activated, engages the high speed clutch means with fast action first, then with slowed action, by timed delay, engages the master clutch next, and then with further slowed action, with timed delay, engages the lockup clutch last to complete said clutched together power path.

Power shifted composite drive to transmit multiple speeds from the engine shaft of an engine, comprising:

• a speed transmission (20) having an input shaft, an output shaft, and plural intervening mechanically synchronized gear ratio trains selectively connected to the output shaft, first means (18) providing a fluid coupling of the engine shaft to said input shaft, and second means (29, 31) in said speed transmission coupling its input shaft to said mechanically synchronized, selective gear ratio trains;
• a synchronized gear ratio range transmission (24) which is step shiftable to provide at least three ranges of speed and powered by a range transmission driving shaft (110) to be driven by said speed transmission output shaft;
• third means (22) comprising a master clutch coupling said output shaft to the driving shaft of the range transmission to be driven thereby;
• means (146, 112, 72, 138, 206, 150, 90, 74) to disengage the master clutch of the just said third coupling to free the range transmission from the inertia of the speed transmission for reduced wear of the synchronized range transmission during shifts between gear ratios, and to disengage the second coupling to free the speed transmission from the inertia of the engine for reduced wear of the mechanical synchronizers therein during changes of the gear ratio train selected;
• said first coupling comprising a high-slip fluid drive and power shift lockup clutch (38) device to transmit engine speed to said speed transmission input shaft for two speed ratio modes of driving same from the engine, and said second coupling comprising selectable torque amplifier power shift clutches to transmit input shaft speed to the selected mechanically synchronized gear ratio train for two speed ratio modes of driving same from the input shaft, and including a power shift high speed clutch means for power shifting to a higher speed;
• power shift operating means (149, 59) to operate said master clutch for coupling the output and driving shafts, and to operate said power shift lockup clutch for power shifting to a higher speed, and to operate said power shift high speed clutch means for power shifting to a higher speed, all to complete a clutched together power path from engine through the range transmission;
• activatable means included in said operating means which, in a tight sequence when activated, engages the high speed clutch means with fast action first, then with slowed action, by timed delay, engages the master clutch next, and then with further slowed action, by timed delay, engages the lockup clutch last to complete said clutched together power path;
• electrical hydraulic means for controlling the engagement and disengagement of the lockup clutch including electrical hydraulic control means (145, 44, 40) responsive to disengagement of the master clutch to effectuate and maintain the lockup clutch in disengagement while the master clutch stays disengaged;
• and
• electrical hydraulic means for controlling the engagement and disengagement of the power shift clutches including electrical hydraulic control means (40, 138, 206, 150, 74, 90) responsive to disengagement of the master clutch to effectuate and maintain the power shift clutches in disengagement while the master clutch stays fully disengaged.

Power shifted composite drive to transmit a selection of multiple speeds from a driving engine comprising:

• a tractor speed transmission with a fluid slip drive and lockup device (18) including a lockup clutch (38), and a power input end (13) ahead of said device, said device arranged to be coupled to the power input end of the transmission;
• said transmission including therein a selective gearing power path which follows said device and which is coupled thereby to the power input end for two speed ratio modes of driving same from said transmission power input end;
• said transmission arranged with a power path output end (110), and with a master clutch (22) in the power path in said power output end effectively in series with the selective gearing and with the fluid drive lockup device;
• said master clutch having slight sustained slip vulnerability and the lockup clutch of said fluid drive lockup device having lesser of such vulnerability as compared to the master clutch;
• activatable means which operates in a tight sequence when activated and which includes
• first means (28) of engaging the master clutch with action first, and
• a slowed action control (44, 46, 48) effective, with timed delay, to engage the lockup clutch second;
• and
• a separate lockup activating control responsive to speed (60) of the driving engine, and referenced to differing engine speed points (1,000 rpm;
• 1,400 rpm) affording hysteresis control responsively disengaging the lockup clutch at a point in speed and re-engaging it always at a predeterminedly higher point.

Power shifted composite drive to transmit a selection of multiple speeds from a driving engine comprising:

• a multispeed transmission with a transmission power input end, and incorporating a power path output end arranged in gear train drive relation to the transmission to be driven thereby;
• said transmission having HI-LO selectable high speed clutches arranged to be coupled to the transmission power input end, arranged with intervening gear ratio trains therefollowing in the transmission, and further arranged with a fluid slip drive and lockup device, including a lockup clutch, in said power input end for coupling it to the selected one of the high speed clutches for two speed ratio modes of driving same therefrom;
• said transmission arranged with a master clutch in the power path in said power output end effectively in series with the intervening gear ratio trains, and with the fluid drive lockup clutch and with the high speed clutches;
• said clutches possessed of differing vulnerability to slip damage, with the high speed clutches having sustained slip vulnerability, said master clutch having less vulnerability, and said lockup clutch being at least vulnerable;
• and
• means of engagement control which operates in a tight sequence when activated and which includes
• fast acting means (80, 94 small) effective to engage the selected high speed clutch first,
• second means (66, 72 large) effective with slowed action, by timed delay, to engage the master clutch second, and
• third means (44, 46, 48) effective with further slowed action, by timed delay, to engage the lockup clutch last.

Mode of operating a multispeed transmission with a power input end, and arranged with a power path output end in gear train drive relation to the transmission to be driven thereby, said transmission having HI-LO selectable high speed clutches arranged to be coupled to the transmission power input end, arranged with intervening gear ratio trains therefollowing in the transmission, and further arranged with a fluid slip drive and lockup device, including a lockup clutch, in said power input end for coupling it to the selected one of the high speed clutches for two speed ratio modes of driving same therefrom, said transmission further arranged with a master clutch in the power path in said power output end effectively in series with the intervening gear ratio trains, and with the fluid drive lockup clutch and with the high speed clutches, said clutches possessed of differing vulnerability to slip damage, with the high speed clutches having sustained slip vulnerability, said master clutch having less vulnerability, and said lockup clutch being least vulnerable, said gear ratio trains including mechanical transmission synchronizers for smooth shifting and constituting together with all clutches aforesaid a shock-free composite drive,

• comprising the steps of:
• declutching the just said composite drive by disengaging all said clutches, and
• making a mechanically synchronized shift in said gear ratio trains from one ratio to a different ratio;
• and
• comprising further, as a tight sequence, the steps of:
• with fast action engaging the selected high speed clutch first,
• engaging with slowed action, by timed delay, the master clutch next, and
• with further slowed action, by timed delay, engaging the fluid drive lockup clutch last to complete a clutched-together composite drive.