Patent ID: 6588562
Filing Date: 2003-07-08
Classification: F16D

Abstract:
A synchronizer for first and second drives disposed for rotation about a common axis and secured against axial movement relative to each other; the synchronizer including:a hub affixed to the first drive and having external splines; a shift sleeve including internal spines continuously mating with the hub external splines and selectively engagable with external splines affixed to the second drive in response to engaging movement of the shift sleeve by a first shift force, and the shift sleeve having first blocker surfaces; a first inner ring having an external cone friction surface; a first cone member rotatable with the second drive and having external and internal cone friction surfaces; a first baulkring mounted for limited rotation relative to the hub and having an internal cone friction surface and second blocker surfaces; pre-energizer means for engaging the baulkring and inner ring friction surfaces respectively with the cone member external and internal friction surfaces in response to initial engaging movement of the shift sleeve by the first shift force and for positioning the blocker surfaces for engagement to prevent asynchronous engagement of the shift sleeve and second drive splines, and to transmit the first shift force to the engaged friction surfaces with an engaging force producing a first synchronizing torque; self-energizing means operative to react the first synchronizing torque for producing a first additive force in the direction of the first shift force for increasing the engagement force of the engaged friction surfaces; the improvement comprising: the first inner ring mounted for limited rotation relative to the hub and having first ramp means, and the self-energizing means including a boost member disposed in a radially extending opening in the hub and moved radially outward by the first ramp means in response to the first synchronizing torque, and the boost member having a first boost surface engagable with a second boost surface affixed to the shift sleeve for producing the first additive force.