Viscous fluid clutch with supplementing centrifugal clutch

Claim 2

A viscous fluid drive mechanism comprising first and second relatively rotatable drive means, said first drive means being rotatably mounted by bearings on a central shaft and having an annular chamber formed therein, said second drive means being secured to said central shaft and extending radially outwardly into said annular chamber so as to provide a predetermined shear space intermediate said first and second drive means, said shear space being operable with a fluid medium to provide a shear-type fluid drive between said first and second drive means, a pair of oppositely disposed slots formed in said first drive means radially outwardly from said second drive means and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheral edge of said second drive means, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and resilient means mounted in each of said pockets for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said first and second drive means until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of the centrifugal force, thereby releasing said lighter ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 3

A viscous fluid drive mechanism comprising first and second relatively rotatable drive means, said first drive means being rotatably mounted by bearings on a central shaft and having an annular chamber formed therein, said second drive means being secured to said central shaft and extending radially outwardly into said annular chamber so as to provide a predetermined shear space intermediate said first and second drive means, said shear space being operable with a fluid medium to provide a shear-type fluid drive between said first and second drive means, a pair of oppositely disposed slots formed in said first drive means radially outwardly from said second drive means and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheRal edge of said second drive means, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said first and second drive means until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighter ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 4

A viscous fluid drive mechanism comprising first and second relatively rotatable drive means, said first drive means being rotatably mounted by bearings on a central shaft and having an annular chamber formed therein, said second drive means being secured to said central shaft and extending radially outwardly into said annular chamber so as to provide a predetermined shear space intermediate said first and second drive means, said shear space being operable with a fluid medium to provide a shear-type fluid drive between said first and second drive means, a pair of oppositely disposed slots formed in said first drive means radially outwardly from said second drive means and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheRal edge of said second drive means, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said first and second drive means until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighter ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 5

A viscous fluid clutch comprising first and second relatively rotatable drive means, said first drive means being rotatably mounted by bearings on a central shaft and having an annular chamber formed therein, said second drive means being secured to said central shaft within said annular chamber, a plurality of annular ridges formed on one of said first and second drive means and a plurality of cooperating annular grooves formed on the other of said first and second drive means in said annular chamber, said annular ridges and grooves forming a shear space therebetween and operable with a fluid medium to provide a shear-type fluid drive between said first and second drive means, a pair of oppositely disposed slots formed in said first drive means radially outwardly from said second drive means and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheral edge of said second drive means, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said first and second drive means until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighter ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 6

A viscous fluid clutch comprising first and second relatively rotatable drive means, said first drive means being rotatably mounted by bearings on a central shaft and having an annular chamber formed therein, said second drive means being secured to said central shaft within said annular chamber, a plurality of annular ridges formed on one of said first and second drive means and a plurality of cooperating annular grooves formed on the other of said first and second drive means in said annular chamber, said annular ridges and grooves forming a shear space therebetween and operable with a fluid medium to provide a shear-type fluid drive between said first and second drive means, a pair of oppositely disposed slots formed in said first drive means radially outwardly from said second drive means and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheral edge of said second drive means, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said first and second drive means until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighter ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 7

A viscous fluid clutch comprising a housing rotatably mounted by bearings on a central shaft and having a working chamber and an adjacent reservoir chamber formed therein, a divider wall sealed between said working chamber and said reservoir chamber, a clutch plate secured to said central shaft within said working chamber, a plurality of annular ridges formed on one of said housing and said clutch plate and a plurality of cooperating annular grooves formed on the other of said housing and said clutch plate in said working chamber, said annular ridges and grooves forming a shear space therebetween and operable with a fluid medium to provide a shear-type fluid drive between said housing and said clutch plate, said divider wall having outlet opening means formed in an outer radial portion thereof and inlet opening means formed at an inner radial portion thereof, pump means formed on one of said divider wall and clutch plate to pump said fluid medium from said working chamber through said outlet opening means into said reservoir chamber, temperature-responsive valve means operatively connected to said inlet opening means for controlling the flow of said fluid medium from said reservoir chamber through said inlet opening means into said working chamber in response to changes in ambient temperature, a pair of oppositely disposed slots Formed in said housing radially outwardly from said clutch plate and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheral edge of said clutch plate, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said clutch plate and said housing until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighten ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.

Claim 8

A viscous fluid clutch comprising a housing rotatably mounted by bearings on a central shaft and having a working chamber and an adjacent reservoir chamber formed therein, a divider wall sealed between said working chamber and said reservoir chamber, a clutch plate secured to said central shaft within said working chamber, a plurality of annular ridges formed on one of said housing and said clutch plate and a plurality of cooperating annular grooves formed on the other of said housing and said clutch plate in said working chamber, said annular ridges and grooves forming a shear space therebetween and operable with a fluid medium to provide a shear-type fluid drive between said housing and said clutch plate, said divider wall having outlet opening means formed in an outer radial portion thereof and inlet opening means formed at an inner radial portion thereof, pump means formed on one of said divider wall and clutch plate to pump said fluid medium from said working chamber through said outlet opening means into said reservoir chamber, temperature-responsive valve means operatively connected to said inlet opening means for controlling the flow of said fluid medium from said reservoir chamber through said inlet opening means into said working chamber in response to changes in ambient temperature, a pair of oppositely disposed slots Formed in said housing radially outwardly from said clutch plate and including a shoulder formed at one end of each of said slots, a pair of oppositely disposed arcuate-shaped pockets formed in the outer peripheral edge of said clutch plate, a centrifugal weight member pivotally mounted at an intermediate but off-center point thereof in each of said pockets, and a leaf spring secured at one end thereof in each of said pockets and extending toward said respective centrifugal weight members for urging the adjacent lighter end of said respective centrifugal weight members radially outwardly into said respective slots for contacting said respective shoulders so as to produce a direct mechanical drive relationship between said clutch plate and said housing until such time as the heavier end of said respective centrifugal weight members pivots radially outwardly under the action of centrifugal force, thereby releasing said lighten ends of said centrifugal weight members from said respective shoulders and permitting said shear-type fluid drive to become effective.