Shifter park position brake-transmission interlock

In a vehicle having an automatic transmission having a Park and other positions, an ignition switch, and a service brake operator, an automatic transmission shifter comprising

• a base mounting a shift gate which defines a plurality of notches corresponding to the Park and other transmission positions,
• a shift lever mounted on the base for pivotable movement between the Park and other transmission positions,
• a locking pin carried by the shift lever for movement along a radial path into the shift gate Park notch to lock the shift lever in Park position and for movement out of said notch to enable shift lever movement out of Park position,
• a blocking arm mounted on the base and having a movable hinge enabling movement of the blocking arm into and out of a blocking position in the path of movement of the locking pin when the shift lever is in Park position and having an outer surface perpendicular to the path of pin movement and engageable by the locking pin to block movement of the locking pin out of said notch, and
• an actuator mounted on the base comprising an electric solenoid normally locating the blocking arm in blocking position and actuatable in response to operation of the service brake operator and closure of the ignition switch to move the blocking arm out of blocking position, characterized by
• the blocking arm hinge enabling the blocking arm to collapse inwardly away from the locking pin along said path in response to pin force upon initial movement of the blocking arm out of blocking position by the solenoid and to enable subsequent movement of the blocking arm by the solenoid to disengage the outer surface from the locking pin.

In a transmission shifter having a shift gate defining a locking notch, a shift lever movable along said gate into and out of alignment with said notch, and a locking pin carried by the lever for movement along a path on the lever into and out of said notch, the improvement comprising

• a blocking arm movable into and out of a normal blocking position in the path of pin movement and having an outer surface engageable by the locking pin, and
• an actuator for moving the blocking arm,
• said blocking arm having a movable hinge which lies to one side of the locking pin path when the locking arm is in blocking position to prevent movement of the blocking arm out of blocking position by a force exerted on the blocking arm outer surface by the locking pin,
• said blocking arm being movable by the actuator to move the hinge to the other side of the locking pin path to enable a force exerted by the locking pin to pivot the blocking arm on the hinge to move the blocking arm surface along said path to disengage the locking pin as the locking arm is moved out of blocking position by the actuator.