Synchronizing mechanism for clutches

A synchronizing mechanism for a clutch which is particularly useful in a transmission for a motor vehicle, comprising

• an axial rotatable shaft,
• a guide sleeve secure to said shaft and rotatable therewith,
• said guide sleeve having external toothing,
• a gear shift sleeve having internal toothing for slidably receiving said external toothing,
• said gear shift sleeve being rotatable with said guide sleeve while being axially slidable along said guide sleeve,
• first and second gears rotatably coaxially with said shaft and disposed on opposite sides of said guide sleeve and said gear shift sleeve,
• said first and second gears having respective first and second clutch bodies thereon with first and second external clutch toothing,
• said gear shift sleeve being slidable for selective meshing of its internal toothing said external clutch toothing on said first and second clutch bodies,
• a first synchronizing ring disposed between said gear shift sleeve and said first gear,
• said first synchronizing ring having from-locking engagement with said gear shift sleeve while being frictionally engageable with said first clutch body,
• said form-locking engagement providing for limited angular play between said first synchronizing ring and said gear shift sleeve,
• a second synchronizing ring disposed between said gear shift sleeve and said second gear,
• said second synchronizing ring having form-locking engagement with said gear shift sleeve while being frictionally engageable with said second clutch body,
• said last-mentioned form-locking engagement providing for limited angular play between said second synchronizing ring and said gear shift sleeve,
• first spring detent means and a first pressure body forming a first connection between said gear shift sleeve and said first synchronizing ring for initially applying axial pressure to said first synchronizing ring to produce frictional engagement between said first synchronizing ring and said first clutch body when said gear shift sleeve is moved axially from its initial neutral position toward said first gear whereby the speeds of said synchronizing ring and said gear shift sleeve are brought into synchronism with the speed of said first gear,
• means forming a first pair of sloping check faces between said gear shift sleeve and said first synchronizing ring,
• said check faces being slidable axially and circumferentially when synchronism is achieved,
• whereby said check faces escape from each other and said internal toothing on said gear shift sleeve slides synchronously into mesh with the first external clutch toothing of the clutch body on said first gear,
• second spring detent means and a second pressure body connected between said gear shift sleeve and said second synchronizing ring for applying axial pressure to said second synchronizing ring and thereby producing frictional engagement between said second synchronizing ring and said second clutch body when said gear shift sleeve is moved axially from its initial neutral position toward said second gear,
• said last-mentioned frictional engagement bringing the speed of said second synchronizing ring and said gear shift sleeve into synchronism with the speed of said second gear,
• and means forming a second pair of sloping check faces between said gear shift sleeve and said second sychronizing ring,
• said second pair of check faces coming into engagement and then sliding axially and circumferentially until said second pair of check faces escape from each other and said internal toothing on said gear shift sleeve slides synchronously into mesh with said second external clutch toothing of the second clutch body on said second gear,
• said second pressure body having a particular portion thereon with an axial spacing between said particular portion and said first synchronizing ring,
• said axial spacing being substantially equal to the axial distance which must be traveled by said gear shift sleeve to cause said check faces of said first pair to escape from each other,
• after which said second spring detent means cause said particular portion of said second pressure body to engage said first synchronizing ring to maintain frictional engagement between said first synchronizing ring and said first clutch body so that synchronism will not be lost as the internal toothing on said gear shift moves into mesh with the external clutch toothing of the first clutch body,
• said first pressure body having a particular portion with a similar axial spacing from said second synchronizing ring,
• said last-mentioned axial spacing being substantially equal to the axial distance which must be traveled by said gear shift sleeve to cause said check faces of said second pair of escape from each other,
• after which said particular portion of said first pressure body engages said second synchronizing ring and maintains frictional engagement between said second synchronizing ring and said second clutch body to prevent loss of synchronism as the internal toothing of said gear shift sleeve moves into mesh with the external toothing of said second clutch body on said second gear.