Transmission lock

Claim 1

IN A SELECTIVE POWER TRANSMISSION LOCK INCLUDING A SHAFT, FIRST AND SECOND EXTERNALLY TOOTHED MEMBERS MOUNTED IN AXIALLY SPACED RELATION ON SAID SHAFT FOR ROTATION RELATIVE THERETO, A SHIFT HUB IN ROTATABLY FIXED RELATION ON THE SHAFT BETWEEN SAID TOOTHED MEMBERS AND HAVING TWO AXIALLY SPACED ROWS OF CICUMFERENTIALLY SPACED EXTERNAL TEETH THEREON ALIGNABLE WITH THE TEETH OF THE TOOTHED MEMBERS, AND A SHIFT COLLAR SHIFTABLE AXIALLY OVER SAID HUB AND TOOTHED MEMBERS AND HAVING FIRST AND SECOND AXIALLY SPACED ROWS OF ALIGNED CIRCUMFERENTIALLY SPACED INTERNAL TEETH ENGAGEABLE WITH THE TEETH OF THE HUB AND TOOTHED MEMBERS AND OF A HEIGHT SUBSTANTIALLY EQUAL TO THAT OF THE HUB TEETH, THE TEETH OF SAID FIRST ROW BEING CHORDALLY WIDER THAN THE TEETH OF SAID SECOND ROWS AND AXIALLY SHORTER THAN THE SPACE BETWEEN SAID TWO ROWS OF TEETH OF THE SHIFT HUB, SAID WIDER TEETH ENGAGING IN CIRCUMFERENTIALLY OVERLAPPED RELATION ALTERNATIVELY WITH THE AXIALLY OUTER AND INNER ENDS OF THE TEETH OF ONE OF THE TWO HUB ROWS UPON SHIFTING OF THE COLLAR TO ENGAGE THE INTERNAL COLLAR TEETH IN DRIVING RELATION WITH THE EXTERNAL TEETH OF THE HUB AND OF ONE OR THE OTHER OF THE TOOTHED MEMBERS AND UPON APPLICATION OF TORQUE, SAID INNER AND OUTER ENDS OF SAID ONE ROW OF TEETH HAVING FLAT ABUTMENT SURFACES, WHEREBY TO PREVENT RETURN SHIFTING OF THE COLLAR DURING SAID TORQUE APPLICATION, THE IMPROVEMENT COMPRISING CHAMFERS ON THE AXIALLY OUTER ENDS OF THE COLLAR TEETH AND ON THE OPPOSED AXIALLY OUTER ENDS OF THE TEETH ON SAID TOOTHED MEMBERS, THE TEETH OF SAID MEMBERS BEING OF LESS HEIGHT THAN THE TEETH OF THE HUB AND COLLAR, AT LEAST THE CHAMFERS ON THE AXIALLY OUTER ENDS OF THE WIDER COLLAR TEETH AND ON THE OPPOSING ENDS OF THE TEETH ON THE AXIALLY ADJACENT TOOTHED MEMBERS EXTENDING FOR LESS THAN THE FULL HEIGHT OF SAID COLLAR TEETH, AND FLAT ABUTMENT SURFACES ON SAID OUTER ENDS OF THE WIDER TEETH AT THE ROOT PORTIONS THEREOF ENGAGEABLE WITH THE ABUTMENT SURFACES ON THE INNER ENDS OF SAID ONE ROW OF HUB TEETH IN ONE SHIFTED POSITION OF THE COLLAR, SAID ABUTMENT SURFACES OF THE WIDER TEETH CLEARING THE TEETH OF SAID AXIALLY ADJACENT TOOTHED MEMBER IN SAID POSITION.