In Chrysler's Turbine Car the excellent flexibility or elasticity of the engine is augmented by a 3-speed automatic transmission. This modified TorqueFlite transmission requires no slip device, such as a hydraulic torque converter, since the power turbine of the engine is independent of the gas generator. Thus the power turbine is connected through its reduction gear directly to the input shaft of the transmission, and a castiron adapter plate is used to mount the transmission to the engine.
Since the engine cannot be started by pushing the car, there is no rear pump on the ransmission, and there is no front pump since pressure for actuating clutches and bands is furnished by the central hydraulic system. To maintain smooth shifting, the hydraulic circuitry of the transmission is modified to adapt the transmission to the output characteristics of the gas turbine engine.
Control Lever Positions
The driver controls automatic transmission settings by a lever mechanism with "Reverse, " "Idle, " "Drive, " and "Low" positions. Position is indicated by a separate cable-driven, barrel-type indicator with "R, " "Idle, " "D, " and "L" call-outs. For convenience and safety, the control lever mechanism is gated, making it necessary to move the control handle sideways before it can be shifted into Reverse or Low. The driver thus can change control lever position merely by "feel" without looking at the indicator.
"Start/Park" position is engaged by pushing downward on the lever when in "Idle" position. With the lever pushed down, a sprag mechanically locks the transmission, and a light on the console indicates that the position is engaged. This "push-in" engagement of "Start/Park" position affords an added safeguard against accidental release, since it takes a positive upward pull to release the lever.
Turbine Over speed Control
Two features are incorporated in the transmission to avoid over speeding of the power turbine. One is automatic up shifting when the control is in "Low. " The other is the substitution of a lock-up "Idle" control-lever position in place of neutral. When the control handle is in "Idle" position and the engine is running, the direct clutch, forward clutch and reverse band are engaged, locking up the transmission. A blocker mechanism prevents engagement of the "Idle" position above about 15 mph.
With the control lever in "Low" position, the transmission, reacting solely to the speed of the car without regard to accelerator pedal position, will up shift to 2nd and 3rd at normal wide-open-throttle up shift speed. It will downshift at wide-open-throttle kick-down limits to give maximum braking. In "Drive" position, the transmission has normal shifting and kickdown behavior, reacting to a combination of both vehicle speed and accelerator position.
The transmission effectively prevents Over speed of the power turbine under normal driving conditions. However, with the transmission control in D, L, or R the turbine wheel could Over speed if the engine were operated with one of the car's rear wheels free to spin- -as on ice or on a hoist. Thus the engine should never be operated with the car on a hoist or a rear wheel jacked off the ground, and if the car is operated on ice or in other slippery conditions that permit a rear wheel to spin, the accelerator pedal should only be depressed intermittently to avoid sustained acceleration of the engine.
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