Dual torque coupling

Claim 2

An improved torque coupling including: a driving member connectable to a driving means for imparting axial rotation to said driving member, a driven member coaxially disposed with respect to said driving member, and engaging means connected to said driven member, said means biased in driven engagement with said driving member for transmitting a unidirectional torsional load to said driving member, wherein the improvement comprises: engagement sustaining means cammably coupled with said engaging means, whereby in response to a torsional load opposite said unidirectional load said sustaining means maintains said engaging means in engagement with said driving member, and control means rigidly connected to said engaging means whereby said engaging means is pivoted into and out of engagement with said driving member in the process of coupling and uncoupling said driven member with and from said driving member.

Claim 3

In a torque coupling having a driving member with a ratchet circularly disposed thereon, said member being axially rotatable by a motor or the like, a driven member disposed coaxially with said driving member and an engaging pawl pivotally mounted on said driven member in biased engagement with the ratchet on said driving member for rotatably coupling said driven member with said driving member under a unidirectional torsional load on the coupling, an improvement comprising: control means rigidly connected to said engaging pawl whereby said engaging pawl is pivoted into and out of engagement with said driving member in the process of coupling and uncoupling said driven member with and from said driving member, and an engagement sustaining pawl pivotally mounted on said driven member and cammably coupled with said engaging pawl, said sustaining pawl being operative to force said engaging pawl into engagement with said ratchet in response to a torsional load opposite said unidirectional load.

Claim 4

In a torque coupling having a driving member with a ratchet circularly disposed thereon, said member being axially rotatable by a motor or the like, a driven member disposed coaxially with said driving member and an engaging pawl pivotally mounted on said driven member in biased engagement with the ratchet on said driving member for rotatably coupling said driven member with said driving member under a unidirectional torsional load on the coupling, an improvement comprising: control means rigidly connected to said engaging pawl whereby said engaging pawl is pivoted into and out of engagement with said driving member in the process of coupling and uncoupling said driven member with and from said driving member, and an engagement sustaining pawl pivotally mounted on said driven member and cammably coupled with said engaging pawl, said sustaining pawl being operative to force said engaging pawl into engagement with said ratchet in response to a torsional load opposite said unidirectional load.

Claim 5

A coupling as defined in claim 2 wherein said engagement sustaining pawl has a tooth biased into engageable contact with the ratchet on said driving member and wherein said cammable coupling of said engagement sustaining pawl and said engaging pawl includes a camming surface of said engagement sustaining pawl, said biased tooth and said camming surface being responsive to a relative torsional load between said driving and said driven members opposite said unidirectional load and effective for imparting a predetermined engagement sustaining force to said engaging pawl to thereby maintain said engaging pawl in firm engagement with said ratchet.

Claim 6

In a torque coupling including a driving member engageable for axial rotation by a motor or the like and a driven member disposed coaxially with said driving member, an improved means for rotatably coupling said driven member with said driving member comprising: an engaging pawl pivotally mounted on one of said members, said pawl having an engaging portion resiliently biased in a first pivotal direction into engagement with the other of said members, control means rigidly connected to said engaging pawl whereby a first moment of force between said pawl and said other member tends to pivot said pawl in said first pivotal direction for rotatably coupling the two said members, and an engagement sustaining pawl pivotally mounted with said engaging pawl on said one member, said sustaining pawl having an engaging sector resiliently biased into engagement with said other member and having also a camming sector resiliently biased in abutment with said engaging pawl, said sustaining pawl being operative upon a second moment of force opposite said first moment of force to cam said engaging pawl in said first pivotal direction and into engagement with said other member.

Claim 7

In a torque coupling including a driving member engageable for axial rotation by a motor or the like and a driven member disposed coaxially with said driving member, an improved means for rotatably coupling said driven member with said driving member comprising: an engaging pawl pivotally mounted on one of said members, said pawl having an engaging portion resiliently biased in a first pivotal direction into engagement with the other of said members, control means rigidly connected to said engaging pawl whereby a first moment of force between said pawl and said other member tends to pivot said pawl in said first pivotal direction for rotatably coupling the two said members, and an engagement sustaining pawl pivotally mounted with said engaging pawl on said one member, said sustaining pawl having an engaging sector resiliently biased into engagement with said other member and having also a camming sector resiliently biased in abutment with said engaging pawl, said sustaining pawl being operative upon a second moment of force opposite said first moment of force to cam said engaging pawl in said first pivotal direction and into engagement with said other member.

Claim 8

A torque coupling as defined in claim 4 further including a biasing means connected to said one member for resiliently biasing said engagement sustaining pawl and said engaging pawl into engagement with said other member.

Claim 9

A dual torque coupling comprising: a driving member engageable for axial rotation by a motor or the like, said driving member comprising a ratchet including a plurality of notches, a driven member disposed coaxially with said driving member, engaging means pivotally mounted on said driven member, said means being pivotal in a first direction into engagement with said driving member and in a second direction out of engagement therewith, engagement sustaining means pivotally mounted on said driven member and cammably coupled with said engaging means, said sustaining means being separately engageable with said driving member, control means rigidly connected to said engaging means and effective for pivoting said engaging means in said first and second directions, and means resiliently biasing said engagement sustaining means, said engaging means, and said control means such that said engaging means is biased in said first pivotal direction, said biased sustaining means in cooperation with said engaging means being non-responsive to a normal torsional load upon said driven member but responsive to a counter torsional load thereupon to apply a torque to said engaging means in said first pivotal direction to thereby force said engaging means into firm engagement with said driving means.

Claim 10

A dual torque coupling comprising: a driving member engageable for axial rotation by a motor or the like, said driving member comprising a ratchet including a plurality of notches, a driven member disposed coaxially with said driving member, engaging means pivotally mounted on said driven member, said means being pivotal in a first direction into engagement with said driving member and in a second direction out of engagement therewith, engagement sustaining means pivotally mounted on said driven member and cammably coupled with said engaging means, said sustaining means being separately engageable with said driving member, control means rigidly connected to said engaging means and effective for pivoting said engaging means in said first and second directions, and means resiliently biasing said engagement sustaining means, said engaging means, and said control means such that said engaging means is biased in said first pivotal direction, said biased sustaining means in cooperation with said engaging means being non-responsive to a normal torsional load upon said driven member but responsive to a counter torsional load thereupon to apply a torque to said engaging means in said first pivotal direction to thereby force said engaging means into firm engagement with said driving means.

Claim 11

A coupling as defined in claim 6 wherein said cammable coupling of said engagement sustaining means with said engaging means is accomplished by an interconnecting camming sector, and wherein the bias of said biasing means is applied to said engagement sustaining means and transmitted to said engaging means through said interconnecting camming sector, to thereby bias said engaging means in said first pivotal direction.

Claim 12

A coupling as defined in claim 7 wherein said engagement sustaining means is rendered separately engageable with said driving member by means of a tooth thereof, said tooth being disposed opposite the pivot point of said Sustaining means from said interconnecting camming sector.

Claim 13

A coupling as defined in claim 8 wherein one face of said tooth of said engagement sustaining means is spaced apart from the corresponding face of a notch of said ratchet engaged thereby, said spacing forming a gap defining the amount of overrun that is permitted the driven member with respect to the driving member while under the influence of counter-torque loading on the coupling.

Claim 14

A coupling as defined in claim 9 wherein said interconnecting camming sector of said engaging means and said engagement sustaining means is effective to cam said sustaining means out of engagement with said driving member when said engaging means is pivoted in said second direction by said control member.

Claim 15

A coupling as defined in claim 9 wherein said biasing means resiliently biases said control member in said first pivotal direction with respect to said driven member for in turn resiliently biasing said engaging means into engagement with said driving member.