Rotary power transmission devices

Claim 1

A synchronous self-shifting toothed clutch of the type comprising first and second rotary clutch parts, co-acting clutch teeth, intermediate means constrained for movement relative to said second rotary clutch part, and clutch actuating means operative upon passage of said first and second rotary clutch parts through synchronism in one direction of relative rotation to shift said intermediate means relative to said second rotary clutch part in the requisite direction to intitiate interengagement of the co-acting clutch teeth, with the improvements comprising first and second rings of clutch teeth carried by said first rotary clutch part, first intermediate means constrained for movement relative to said second rotary clutch part, a third ring of clutch teeth carried by said first intermediate means, a second intermediate means constrained for movement relative to said second rotary clutch part, a fourth ring of clutch teeth carried by said second intermediate means, said clutch actuating means operative upon passage of said first and second rotary clutch parts through synchronism in one direction of relative rotation to shift said first intermediate means in the requisite direction to initiate interengagement of said first and third rings of clutch teeth whereby to establish a first power path between said first and second rotary clutch parts and conjointly to shift said second intermediate means in the requisite direction to intitiate interengagement of said second and fourth rings of clutch teeth whereby to establish a second power path between said first and second rotary clutch parts, said first and second power paths each including helical driving surfaces and said first and second intermediate means, in the engaged condition of the clutch, reacting on one another such that the load is shared between said first and second power paths.