Electromagnetically operable friction clutch

Claim 2

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; said clutch having rotary input and output members; wherein said second disc is comprised of a pair of concentric rings of magnetic material spaced by an air gap; said rings being secured to a dish spring and said spring being secured to one of said rotary members of said clutch, whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet; each of said rings of said second disc having a groove in the face thereof effecting a pair of pole faces for each ring whereby four coplanar pole faces for said second disc are achieved.

Claim 3

An electromagnetic clutch as set forth in claim 1 the groove in the innermost of said rings being filled with a non-magnetic material.

Claim 4

An electromagnetic clutch as set forth in claim 1, including rivets secured to said rings and passing through said spring and being deformed to secure said rings to said spring; said rivets extending outwardly of said spring to a predetermined distance; said one rotary member of said clutch comprising a radial flange coaxial with said second disc and said second disc being drawn against said flange by said spring to a limiting position effected by the extending portions of said rivets engaging said flange.

Claim 5

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; including a dish spring and rivets secured to said rings of said second disc and passing through said spring and being deformed to secure said rings to said spring to maintain said rings spaced by an air gap; said rivets extending outwardly of said spring to a predetermined distance; said clutch comprising a radial flange coaxial with said second disc and said second disc being drawn against said flange by said spring to a limiting position effected by the extending portions of said rivets engaging said flange; said clutch including said driving and driven members, and one of said members comprising said flange; whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet.

Claim 6

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; including a dish spring and rivets secured to said rings of said second disc and passing through said spring and being deformed to secure said rings to said spring to maintain said rings spaced by an air gap; said rivets extending outwardly of said spring to a predetermined distance; said clutch comprising a radial flange coaxial with said second disc and said second disc being drawn against said flange by said spring to a limiting position effected by the extending portions of said rivets engaging said flange; said clutch including said driving and driven members, and one of said members comprising said flange; whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet.

Claim 7

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque Upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; said clutch having rotary input and output members; wherein said second disc is comprised of a pair of concentric rings of magnetic material spaced by an air gap; said rings being secured to a dish spring and said spring being secured to one of said rotary members of said clutch, whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet; each of said rings of said second disc having a groove in the face thereof effecting a pair of pole faces for each ring whereby four coplanar pole faces for said second disc are achieved; including rivets secured to said rings and passing through said spring and being deformed to secure said rings to said spring; said rivets extending outwardly of said spring to a predetermined distance; said one rotary member of said clutch comprising a pulley having a radial flange coaxial with said second disc and said second disc being drawn against said flange by said spring to a limiting position effected by the extending portions of said rivets engaging said flange whereby said spring is pre-stressed.

Claim 8

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque Upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; said clutch having rotary input and output members; wherein said second disc is comprised of a pair of concentric rings of magnetic material spaced by an air gap; said rings being secured to a dish spring and said spring being secured to one of said rotary members of said clutch, whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet; each of said rings of said second disc having a groove in the face thereof effecting a pair of pole faces for each ring whereby four coplanar pole faces for said second disc are achieved; including rivets secured to said rings and passing through said spring and being deformed to secure said rings to said spring; said rivets extending outwardly of said spring to a predetermined distance; said one rotary member of said clutch comprising a pulley having a radial flange coaxial with said second disc and said second disc being drawn against said flange by said spring to a limiting position effected by the extending portions of said rivets engaging said flange whereby said spring is pre-stressed.

Claim 9

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; said clutch having rotary input and output members; wherein said second disc is comprised of a pair of concentric rings of magnetic material spaced by an air gap; a dish spring; said rings being secured to said dish spring and said spring being secured to one of said rotary members of said clutch, whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet; each of said rings of said second disc having a groove in the face thereof effecting a pair of pole faces for each ring whereby four coplanar pole faces for said second disc are achieved; another of said rotary members being a shaft; said electromagnetic comprising a magnet body having portions effecting the pole faces of said electromagnet and encompassing said shaft; said first disc being keyed to said shaft and carried thereon adjacent said magnet body pole faces; said one of said rotary members being a pulley and having a side flange to which said dish spring is secured; said pulley being rotatively supported on said shaft.

Claim 10

An electromagnetic clutch comprising an electromagnet having pole faces and means fixedly supporting said electromagnet; a first friction disc adjacent the pole faces of said electromagnet and having a plurality of spaced magnetic rings magnetically isolated from each other; a second friction disc coaxial with said first disc and comprising a plurality of magnetic rings magnetically isolated from each other and disposed to effect a flux path with the rings of said first disc whereby flux effected upon energization of said electromagnet follows reentrant paths comprised of pairs of pole faces on each said disc; said discs being relatively movable axially to engage each other to transmit torque upon said energization of said electromagnet; and means for rotatively mounting said friction discs to transmit torque from a driving to a driven member; said clutch having rotary input and output members; wherein said second disc is comprised of a pair of concentric rings of magnetic material spaced by an air gap; a dish spring; said rings being secured to said dish spring and said spring being secured to one of said rotary members of said clutch, whereby said second disc flexes said spring to move axially toward said first disc for engagement therewith upon said energization of said electromagnet; each of said rings of said second disc having a groove in the face thereof effecting a pair of pole faces for each ring whereby four coplanar pole faces for said second disc are achieved; another of said rotary members being a shaft; said electromagnetic comprising a magnet body having portions effecting the pole faces of said electromagnet and encompassing said shaft; said first disc being keyed to said shaft and carried thereon adjacent said magnet body pole faces; said one of said rotary members being a pulley and having a side flange to which said dish spring is secured; said pulley being rotatively supported on said shaft.