Self-energizing synchronizer including force limiting

A synchronizer selectively operative to frictionally synchronize and positively connect either of first and second drives respectively mounted for relative rotation about an axis of a shaft;

• the synchronizer including:
• first and second jaw members affixed respectively to the first and second drives and respectively engagable with axially movable third and fourth jaw members in response to an engaging movement thereof by an axial bidirectional shift force (F.sub.o), the third and fourth jaw members mounted for non-rotation and for axial movement relative to the shaft;
• first and second friction members respectively secured for rotation with the first and second drives, and third and fourth friction members axially movable into frictional engagement respectively with the first and second friction members to provide a synchronizing torque between the drives and the shaft in response to the engaging movement;
• blocker means movable into engagement in response to the engaging movement of either of the third and fourth jaw members for preventing asynchronous engagement of the jaw members and for transmitting the shift force (F.sub.o) to effect an engagement force of the friction members;
• first self-energizing means affixed against movement relative to the shaft, second self-energizing means engagable with the first self-energizing means in response to the torque transmitted thereto, and the first and second self-energizing means operative when engaged to produce an additive force (F.sub.a) in a direction of the shift force (F.sub.o) for increasing the engagement force of the friction members;
• the improvement comprising:
• force limiting means for limiting the additive force (F.sub.a) to a predetermined amount of the torque and including resilient means and stop means, the resilient means for flexibly transmitting the torque between the blocker means and the second self-energizing means, flexing of the resilient means in response to the torque causing relative rotation between the blocker means and the second self-energizing means, and the stop means operative when engaged in response to the predetermined amount of the torque and the relative rotation to connect the blocker means to the second drive in a bypass torque path in driving parallel with the resilient means to limit the torque reacted by the first and second self-energizing means to the predetermined amount of the torque.

A synchronizer selectively operative to frictionally synchronize and positively connect either of first and second drives respectively mounted for relative rotation about an axis of a shaft;

• the synchronizer including:
• first and second jaw members affixed respectively to the first and second drives and respectively engagable with axially movable third and fourth jaw members in response to an engaging movement thereof by an axial bidirectional shift force (F.sub.o), the third and fourth jaw members mounted for non-rotation and for axial movement relative to the shaft;
• first and second friction members respectively secured for rotation with the first and second drives and third and fourth friction members axially movable into frictional engagement respectively with the first and second friction members to provide a synchronizing torque between the drives and the shaft in response to the engaging movement;
• a radially extending flange having axially oppositely facing sides positioned between the third and fourth jaw members and between the third and fourth friction members for axially moving the jaw members and friction members into said engagements in response to the bi-directional shift force (F.sub.o) applied to the flange;
• retainer means for securing the flange against axial movement relative to the third and fourth jaw members;
• stop means for limiting rotation of the flange relative to the third and fourth jaw members;
• blocker means movable into engagement in response to the engaging movement of either of the third and fourth jaw members for preventing asynchronous engagement with the first and second jaw members and for transmitting the shift force (F.sub.o) to effect an engagement force of the friction members for increasing the engagement force thereof, the blocker means including a plurality of circumferentially spaced apart pins rigidly extending axially between the third and fourth friction members and into a first set of openings in the flange, each of the pins having blocker shoulders engagable with blocker shoulders defined about an associated one of the openings;
• first self-energizing means affixed against movement relative to the shaft, second self-energizing means engagable with the first self-energizing means in response to the torque transmitted thereto via a torque path including the blocker means and the flange, the first and second self-energizing means operative when engaged to produce an additive force (F.sub.a) in a direction of the shift force (F.sub.o) for further increasing the engagement force of the friction members, and the second self-energizing means secured against axial movement relative to the flange;
• the improvement comprising:
• force limiting means for limiting the additive force (F.sub.a), the force limiting means including resilient means for connecting the flange for rotation with the second self-energizing means, the resilient means allowing engagement of the stop means when flexed by a predetermined amount of the torque, and the stop means rotationally connecting the flange to the shaft in a bypass torque path in driving parallel with the resilient means to limit the torque reacted by the first and second self-energizing means to the predetermined amount of the torque.