Load responsive torque transmission mechanism

Claim 2

In a torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude, said mechanism further including a stationary housing and a normally inactive planetary gear set disposed therein between said input and said output shafts and said planetary gear set including one element adapted for rigid connection to one of said housing and said input shaft to effect torque transmission through said planetary set, a torque responsive clutch system comprising, means defining a keeper on said input shaft, pawl means disposed on said output shaft for unitary rotation therewith and for generally radial bodily movement relative thereto between an extended position engaging said keeper to directly couple saId input and said output shafts for unitary ratio torque transfer and a retracted position remote from said keeper permitting relative angular movement between said input and said output shafts, spring means urging said pawl means toward the extended position thereof, cam means on said input shaft responsive to application of torque to said input shaft of magnitude exceeding a predetermined minimum magnitude to shift said pawl means against said spring means from the extended to the retracted position thereof, a pair of coupling elements disposed on said output shaft on opposite sides of said pawl and adapted to be engaged by the latter during movement from the extended to the retracted position and bodily shifted laterally relative thereto, second cam means associated with said coupling elements adapted to engage said coupling elements during lateral movement thereof and to impart thereto an axial component of bodily motion, lock means disposed on said one rigidly connectable planetary gear set element and adapted for movement between an unlocked position and a locked position rigidly connecting said one element to said one of said housing and said input shaft, and means connecting said coupling elements to said lock means responsive to the axial motion component of said coupling elements to move said lock means from the unlocked to the locked position thereof.

Claim 3

In a torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude, said mechanism further including a stationary housing and a normally inactive planetary gear set disposed therein between said input and said output shafts and said planetary gear set including one element adapted for rigid connection to one of said housing and said input shaft to effect torque transmission through said planetary set, a torque responsive clutch system comprising, means defining a keeper on said input shaft, pawl means disposed on said output shaft for unitary rotation therewith and for generally radial bodily movement relative thereto between an extended position engaging said keeper to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position remote from said keeper permitting relative angular movement between said input and said output shafts, a plurality of spherical rolling elements disposed around a portion of said output shaft on opposite sides of said pawl means, each of said rolling elements being in contact with the ones of said plurality of rolling elements on opposite sides thereof and the two of said rolling elements situated adjacent opposite sides of said pawl means being engageable by the latter during movement thereof from the extended toward the retracted position thereby to effect lateral movement of each of said rolling elements relative to said pawl means, cam means associated with said rolling elements and engageable on each of said rolling elements during lateral movement of each to impart thereto an axial component of bodily movement, lock means disposed on said one rigidly connectable planetary gear set element and adapted for axial bodily movement between an unlocked position and a locked position rigidly connecting said one element to said one of said housing and said input shaft, spring means between said lock means and said one element biasing the latter toward the unlocked position thereof, means establishing a connection between said lock means and said rolling elements whereby the axial motion component of the latter effects movement of said lock means from the unlocked to the locked position and whereby the bias imposed on said lock means urges said rolling elements to the positions thereof corresponding to the extended position of said pawl means so that the latter is thereby resiliently biased toward the extenDed position thereof, and cam means on said input shaft responsive to application of torque to said input shaft of magnitude exceeding a predetermined minimum magnitude to shift said pawl means against said spring means from the extended to the retracted position thereof.

Claim 4

In a torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude, said mechanism further including a stationary housing and a normally inactive planetary gear set disposed therein between said input and said output shafts and said planetary gear set including one element adapted for rigid connection to one of said housing and said input shaft to effect torque transmission through said planetary set, a torque responsive clutch system comprising, means defining a keeper on said input shaft, pawl means disposed on said output shaft for unitary rotation therewith and for generally radial bodily movement relative thereto between an extended position engaging said keeper to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position remote from said keeper permitting relative angular movement between said input and said output shafts, a plurality of spherical rolling elements disposed around a portion of said output shaft on opposite sides of said pawl means, each of said rolling elements being in contact with the ones of said plurality of rolling elements on opposite sides thereof and the two of said rolling elements situated adjacent opposite sides of said pawl means being engageable by the latter during movement thereof from the extended toward the retracted position thereby to effect lateral movement of each of said rolling elements relative to said pawl means, cam means associated with said rolling elements and engageable on each of said rolling elements during lateral movement of each to impart thereto an axial component of bodily movement, lock means disposed on said one rigidly connectable planetary gear set element and adapted for axial bodily movement between an unlocked position and a locked position rigidly connecting said one element to said one of said housing and said input shaft, spring means between said lock means and said one element biasing the latter toward the unlocked position thereof, means establishing a connection between said lock means and said rolling elements whereby the axial motion component of the latter effects movement of said lock means from the unlocked to the locked position and whereby the bias imposed on said lock means urges said rolling elements to the positions thereof corresponding to the extended position of said pawl means so that the latter is thereby resiliently biased toward the extenDed position thereof, and cam means on said input shaft responsive to application of torque to said input shaft of magnitude exceeding a predetermined minimum magnitude to shift said pawl means against said spring means from the extended to the retracted position thereof.

Claim 5

In a torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude, said mechanism further including a stationary housing and a normally inactive planetary gear set disposed therein between said input and said output shafts and said planetary gear set including one element adapted for rigid connection to one of said housing and said input shaft to effect torque transmission through said planetary set, a torque responsive clutch system comprising, means defining a cylindrical bearing surface on said input shaft having an axial groove therein the opposite sides of which define a pair of cam surfaces, means defining a cylindrical portion on said output shaft disposed about said cylindrical surface on said input shaft, means defining a receptacle slot in said cylindrical portion registerable with said axial groove, a cylindrical pawl disposed in said slot for rotation as a unit with said output shaft and for radial bodily movement relative thereto between an extended position wherein said pawl is situated in said slot and in said groove thereby to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position wherein said pawl is situated in said slot remote from said groove thereby to permit relative angular movement between said input and said output shafts, spring means urging said pawl toward the extended position thereof, one of said cam surfaces being engageable on said pawl in the extended position thereof and operative in response to application of torque exceeding a predetermined minimum magnitude to said input shaft to cam said pawl from the extended to the retracted position thereof against said spring means, a pair of coupling elements disposed on said output shaft on opposite sides of said pawl and adapted to be engaged by the latter during movement thereof from the extended to the retracted position and bodily moved laterally relative thereto, second cam means associated with said coupling elements and engageable on said coupling elements during lateral movement thereof to impart thereto an axial component of bodily motion, lock means disposed on said one rigidly connectable planetary gear set element and adapted for axial bodily movement between an unlocked position and a locked position rigidly connecting said one element to said one of said housing and said input shaft, and means connecting said coupling elements to said lock means responsive to the axial motion component of said coupling elements to move said lock means from the unlocked to the locked position thereof.

Claim 6

In a torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude, said mechanism further including a stationary housing and a normally inactive planetary gear set disposed therein between said input and said output shafts and said planetary gear set including one element adapted for rigid connection to one of said housing and said input shaft to effect torque transmission through said planetary set, a torque responsive clutch system comprising, means defining a cylindrical bearing surface on said input shaft having an axial groove therein the opposite sides of which define a pair of cam surfaces, means defining a cylindrical portion on said output shaft disposed about said cylindrical surface on said input shaft, means defining a receptacle slot in said cylindrical portion registerable with said axial groove, a cylindrical pawl disposed in said slot for rotation as a unit with said output shaft and for radial bodily movement relative thereto between an extended position wherein said pawl is situated in said slot and in said groove thereby to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position wherein said pawl is situated in said slot remote from said groove thereby to permit relative angular movement between said input and said output shafts, spring means urging said pawl toward the extended position thereof, one of said cam surfaces being engageable on said pawl in the extended position thereof and operative in response to application of torque exceeding a predetermined minimum magnitude to said input shaft to cam said pawl from the extended to the retracted position thereof against said spring means, a pair of coupling elements disposed on said output shaft on opposite sides of said pawl and adapted to be engaged by the latter during movement thereof from the extended to the retracted position and bodily moved laterally relative thereto, second cam means associated with said coupling elements and engageable on said coupling elements during lateral movement thereof to impart thereto an axial component of bodily motion, lock means disposed on said one rigidly connectable planetary gear set element and adapted for axial bodily movement between an unlocked position and a locked position rigidly connecting said one element to said one of said housing and said input shaft, and means connecting said coupling elements to said lock means responsive to the axial motion component of said coupling elements to move said lock means from the unlocked to the locked position thereof.

Claim 7

A torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude comprising in combination, a stationary housing rotatably supporting said input and said output shafts in axial alignment, an input sun gear rigidly attached to said input shaft, a planet carrier rotatably disposed in said housing, a set of input planet gears rotatably supported on said planet carrier and meshingly engaging said input sun gear, a ring gear rotatably disposed in said housing and meshingly engaging each of said input planet gears, a set of output planet gears rotatably supported on said carrier and meshingly engaging said ring gear, an output sun gear rigidly attached to said output shaft and meshingly engaging each of said output planet gEars, means defining a cylindrical bearing surface on said input shaft having an axial groove therein the opposite sides of which define a pair of cam surfaces, means defining a cylindrical portion on said output shaft disposed about said cylindrical surface on said input shaft, means defining a receptacle slot in said cylindrical portion registerable with said axial groove, a cylindrical pawl disposed in said slot for rotation as a unit with said output shaft and for radial bodily movement relative thereto between an extended position wherein said pawl is situated in said slot and in said groove thereby to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position wherein said pawl is situated in said slot remote from said groove thereby to permit relative angular movement between said input and said output shafts, a plurality of spherical rolling elements disposed around a portion of said output shaft on opposite sides of said pawl, each of said rolling elements being in contact with the ones of said plurality of rolling elements on opposite sides thereof and the two of said rolling elements situated adjacent opposite sides of said pawl being engageable by the latter during movement thereof from the extended toward the retracted position thereby to effect lateral movement of each of said rolling elements relative to said pawl, cam means on said output shaft engageable on each of said rolling elements during lateral movement thereof to impart thereto an axial component of bodily movement, a plurality of lock pins disposed on said planet carrier for axial bodily movement relative thereto between a locked position engaging an abutment on said housing thereby to lock said planet carrier against rotation relative to said housing and a retracted position remote from said housing permitting rotation of said planet carrier, spring means disposed between each of said lock pins and said planet carrier biasing said lock pins toward the unlocked position thereof, and means establishing a connection between said lock pins and said rolling elements whereby the axial motion component of the latter effects movement of said lock pins from the unlocked to the locked position and the bias imposed on said lock pins urges said rolling elements to the positions thereof corresponding to the extended position of said pawl so that the latter is thereby resiliently biased toward the extended position thereof, one of said cam surfaces of said groove being operable to cam said pawl from the extended to the retracted position thereof in response to the application of torque exceeding a predetermined minimum magnitude to said input shaft thereby to move said lock pins from the unlocked to the locked position thereof so that torque is transferred from said input shaft to said output shaft through said sun gears and said ring gears and said planet gears at a transmission ratio exceeding unity.

Claim 8

A torque transmission mechanism adapted to normally effect torque transfer between a rotating input shaft and a rotating output shaft at a unitary transmission ratio and to automatically shift to a higher transmission ratio in response to torque input exceeding a predetermined minimum magnitude comprising in combination, a stationary housing rotatably supporting said input and said output shafts in axial alignment, an input sun gear rigidly attached to said input shaft, a planet carrier rotatably disposed in said housing, a set of input planet gears rotatably supported on said planet carrier and meshingly engaging said input sun gear, a ring gear rotatably disposed in said housing and meshingly engaging each of said input planet gears, a set of output planet gears rotatably supported on said carrier and meshingly engaging said ring gear, an output sun gear rigidly attached to said output shaft and meshingly engaging each of said output planet gEars, means defining a cylindrical bearing surface on said input shaft having an axial groove therein the opposite sides of which define a pair of cam surfaces, means defining a cylindrical portion on said output shaft disposed about said cylindrical surface on said input shaft, means defining a receptacle slot in said cylindrical portion registerable with said axial groove, a cylindrical pawl disposed in said slot for rotation as a unit with said output shaft and for radial bodily movement relative thereto between an extended position wherein said pawl is situated in said slot and in said groove thereby to directly couple said input and said output shafts for unitary ratio torque transfer and a retracted position wherein said pawl is situated in said slot remote from said groove thereby to permit relative angular movement between said input and said output shafts, a plurality of spherical rolling elements disposed around a portion of said output shaft on opposite sides of said pawl, each of said rolling elements being in contact with the ones of said plurality of rolling elements on opposite sides thereof and the two of said rolling elements situated adjacent opposite sides of said pawl being engageable by the latter during movement thereof from the extended toward the retracted position thereby to effect lateral movement of each of said rolling elements relative to said pawl, cam means on said output shaft engageable on each of said rolling elements during lateral movement thereof to impart thereto an axial component of bodily movement, a plurality of lock pins disposed on said planet carrier for axial bodily movement relative thereto between a locked position engaging an abutment on said housing thereby to lock said planet carrier against rotation relative to said housing and a retracted position remote from said housing permitting rotation of said planet carrier, spring means disposed between each of said lock pins and said planet carrier biasing said lock pins toward the unlocked position thereof, and means establishing a connection between said lock pins and said rolling elements whereby the axial motion component of the latter effects movement of said lock pins from the unlocked to the locked position and the bias imposed on said lock pins urges said rolling elements to the positions thereof corresponding to the extended position of said pawl so that the latter is thereby resiliently biased toward the extended position thereof, one of said cam surfaces of said groove being operable to cam said pawl from the extended to the retracted position thereof in response to the application of torque exceeding a predetermined minimum magnitude to said input shaft thereby to move said lock pins from the unlocked to the locked position thereof so that torque is transferred from said input shaft to said output shaft through said sun gears and said ring gears and said planet gears at a transmission ratio exceeding unity.