Patent ID: 8887887

Claim:
A synchronizing device for a transmission comprising: a clutch hub splined on a rotation shaft and having a plurality of key guide grooves formed at an exterior circumference thereof; a sleeve engaged to an external circumferential portion of the clutch hub by interposing a blocking key therebetween, the sleeve being movable axially in an axis of the rotation shaft and the blocking key being slidably disposed in the key guide grooves in an axial direction of the clutch hub; a clutch gear having a cone surface and disposed at both sides of the sleeve without an interference with the rotation shaft; and a blocker ring disposed between the clutch hub and the clutch gear and frictionally engaged to the cone surface of the clutch gear; wherein each of the key guide grooves has a wider width portion and a narrower width portion extending from a circumferential edge of the clutch hub along an axial direction of the clutch hub, the wider width portion and the narrower width portion being positioned in opposite directions from each other along the axial direction of the clutch hub; wherein the key guide grooves include first and second key guide grooves disposed alternately along a circumferential direction of the clutch hub, the wider width portion of the first key guide groove faces toward one side and the wider width portion of the second key guide groove faces toward the other side, and the wider width portion of the first guide groove and the narrower width portion of the second guide portion are disposed alternatively along the circumferential edge of the clutch hub; and wherein the blocker ring includes a servo load exerted portion axially facing the wider width portion of the first key guide groove and a key load exerted portion axially facing the narrower width portion of the second key groove and disposed alternately in a circumferential direction of the blocker ring, each of the servo load exerted portion and the key load exerted portion respectively has a key contacting surface, and the key contacting surface of the servo load exerted portion is disposed axially apart from the key contacting surface of the key load exerted portion by a predetermined distance.