Power transmission systems

Claim 2

A power transmission system comprising an input shaft, an output shaft, a main clutch and a subsidiary clutch arranged in parallel between said input shaft and said output shaft, each of said clutches being of the type comprising a first rotary clutch member, clutch teeth carried by said first clutch member, a second rotary clutch member, an intermediate member, clutch teeth carried by said intermediate member, and means constraining said intermediate member for helical movement relative to said second clutch member to bring its clutch teeth into and out of driving interengagement with the clutch teeth carried by said first clutch member, such that following partial driving interengagement of the coacting clutch teeth the clutch is selfengaging due to the interaction of the clutch teeth, only said main clutch including means for automatically initiating movement of the intermediate member of said main clutch in the direction for engagement of said main clutch upon passage of the first and second clutch members of said main clutch through rotational synchronism due to relative rotation of said input and output shafts in one direction, the improvement including a lost motion driving connection between the intermediate members of the clutches, which driving connection is operative, during movement of the intermediate member of the main clutch to effect partial driving interengagement of the clutch teeth of the main clutch, to shift the intermediate member of the subsidiary clutch to bring about partial driving interengagement of the clutch teeth of the subsidiary clutch, and means operative during the subsequent self-engaging action of the subsidiary clutch to bring the lost motion into effect.

Claim 3

A power transmission system according to claim 1 wherein the said means for automatically initiating movement of the intermediate member of the main clutch include pawls carried by one of first and intermediate members of the main clutch and ratchet teeth carried by the other of said first and intermediate members of the main clutch, the system including means operative during the clutch engaging movement of the intermediate member of the main clutch to relieve said pawls and ratchet teeth from load before said lost motion driving connection begins to shift the intermediate member of the subsidiary clutch in the direction for engagement of the subsidiary clutch.

Claim 4

A power transmission system according to claim 1 wherein said lost motion driving connection includes a lever, means pivotally mounting said lever to provide lever arms of unequal lengths, means providing a driving connection between one of said lever arms and the intermediate member of the main clutch, and means providing a driving connection between the other of said lever arms and the intermediate member of the subsidiary clutch, at least one of said driving connections being a lost motion driving connection.

Claim 5

A power transmission system according to claim 1 wherein said lost motion driving connection includes a lever, means pivotally mounting said lever to provide two lever arms, means providing a driving connection between one of said lever arms and the intermediate member of the main clutch, and means providing a driving connection between the other of said arms and the intermediate member of the subsidiary clutch, at least one of said driving connections being a lost motion driving connection, with the feature that the lead of the helical motion of the intermediate member of the main clutch relative to the second member of the main clutch is different from the lead of the helical motion of the intermediate member of the subsidiary clutch relative to the second clutch member of the subsidiary clutch.

Claim 6

A power transmission system according to claim 1 including means whereby the shifting of the intermediate member of the subsidiary clutch by the intermediate member of the main clutch effects partial interengagement of the coacting clutch teeth of the subsidiary clutch with rotational clearances, followed by the said partial driving interengagement of the clutch teeth of the subsidiary clutch.

Claim 7

A power transmission system according to claim 1 including sets of transfer teeth carried respectively by the intermediate member of said main clutch and the said first clutch member of said main clutch, said sets of transfer teeth having coacting faces mutually arranged to enter into partial flanking interengagement before said lost motion is taken up and then to slide relatively to one another to produce partial interengagement of the clutch teeth of the subsidiary clutch with rotational clearances, followed by axial disengagement of one set of transfer teeth from the other set to permit the said partial driving interengagement of the clutch teeth of said subsidiary clutch.

Claim 8

A power transmission system according to claim 1 including sets of transfer teeth carried respectively by the intermediate member of said main clutch and the said first clutch member of said main clutch, said sets of transfer teeth having coacting faces mutually arranged to enter into partial flanking engagement before the said lost motion is taken up and then to slide relatively to one another to produce partial interengagement of the clutch teeth of the subsidiary clutch with rotational clearances, followed by further relative sliding of said sets of transfer teeth to permit the said partial driving interengagement of the clutch teeth of said subsidiary clutch.

Claim 9

A power transmission system according to claim 1 wherein the driving flanks of the clutch teeth of said subsidiary clutch are chamfered such that the shifting of the intermediate member of the subsidiary clutch by the intermediate member of the main clutch effects partial interengagement of the coacting clutch teeth of the subsidiary clutch with rotational clearances, followed by the said partial driving interengagement of the clutch teeth of the subsidiary clutch.

Claim 10

A power transmission system comprising an input shaft, an output shaft, a main clutch and a subsidiary clutch arranged in parallel between said input shaft and said output shaft, each of said clutches being of the type comprising a first rotary clutch member, clutch teeth carried by said first clutch member, a second rotary clutch member, an intermediate member, clutch teeth carried by said intermediate member, and means constraining said intermediate member for helical movement relative to said second clutch member to bring its clutch teeth into and out of driving interengagement with the clutch teeth carried by said first clutch member, such that following partial driving interengagement of the coacting clutch teeth the clutch is self-engaging due to the interaction, only said main clutch including means for automatically initiating movement of the intermediate member of the main clutch in the direction for engagement of the main clutch upon passage if the first and second clutch members of the main clutch through rotational synchronism due to relative rotation of said input and output shafts in one direction, the improvement including means mounting said main and subsidiary clutches in relative positions such that with the clutches disengaged the intermediate members of the clutches are axially spaced from one another and such that during movement of the intermediate member of the main clutch into a position of partial driving interengagement of the clutch teeth of the main clutch it moves towards and then shifts the intermediate member of the subsidiary clutch to a position of partial driving interengagement of the clutch teeth of the subsidiary clutch, with the feature that the lead of the helical motion of the intermediate member of the subsidiary clutch relative to the second clutch member of the subsidiary clutch is greater thAn the lead of the helical motion of the intermediate member of the main clutch relative to the second clutch member of the main clutch, with the effect that the self-engaging motions of the intermediate members cause them to separate axially.

Claim 11

A power transmission system comprising an input shaft, an output shaft, a main clutch and a subsidiary clutch arranged in parallel between said input shaft and said output shaft, each of said clutches being of the type comprising a first rotary clutch member, clutch teeth carried by said first clutch member, a second rotary clutch member, an intermediate member, clutch teeth carried by said intermediate member, and means constraining said intermediate member for helical movement relative to said second clutch member to bring its clutch teeth into and out of driving interengagement with the clutch teeth carried by said first clutch member, such that following partial driving interengagement of the coacting clutch teeth the clutch is self-engaging due to the interaction, only said main clutch including means for automatically initiating movement of the intermediate member of the main clutch in the direction for engagement of the main clutch upon passage if the first and second clutch members of the main clutch through rotational synchronism due to relative rotation of said input and output shafts in one direction, the improvement including means mounting said main and subsidiary clutches in relative positions such that with the clutches disengaged the intermediate members of the clutches are axially spaced from one another and such that during movement of the intermediate member of the main clutch into a position of partial driving interengagement of the clutch teeth of the main clutch it moves towards and then shifts the intermediate member of the subsidiary clutch to a position of partial driving interengagement of the clutch teeth of the subsidiary clutch, with the feature that the lead of the helical motion of the intermediate member of the subsidiary clutch relative to the second clutch member of the subsidiary clutch is greater thAn the lead of the helical motion of the intermediate member of the main clutch relative to the second clutch member of the main clutch, with the effect that the self-engaging motions of the intermediate members cause them to separate axially.