Rotary electromagnetic actuator

Claim 2

A rotary electromagnetic actuator comprising a pair of spaced pole pieces, and a rotor mounted for rotation from a deenergized position to an energized position about an axis between the pole pieces, said rotor having a first semicircular portion having its diameter in an axial plane and its center of curvature offset on one side of said axis, and a second semicircular portion also having its diameter in said axial plane and its center of curvature offset on the other side of said axis, said pole pieces having curved pole faces opposed to said rotor portions for forming a pair of curved gaps therebetween, the centers of curvature of said curved pole faces each being offset on an opposite side of said axis, the centers of curvature of said pole faces being coincident with the centers of curvature of adjacent rotor portions when said rotor is in its energized position, the radii of curvature of said rotor portions and the radii of curvature of said pole faces being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotor is in its said deenergized position and being contiguous to said curved pole faces when said rotor is in its energized position.

Claim 3

An actuator as in claim 1 wherein said pole pieces and rotor portions are formed of a nonretentive magnetic material, and means are provided for oppositely polarizing adjacent pole pieces and rotor portions.

Claim 4

An actuator as in claim 1 further comprising means for returning said rotor from its energized position to its deenergized position.

Claim 5

An actuator as in claim 1 wherein each of the curved gaps vary in width from a maximum at one of their ends to a minimum at the other of their ends.

Claim 6

A limited travel rotary electromagnetic actuator comprising a pair of spaced pole pieces having arcuately configured pole faces, said pole pieces being formed of a nonretentive magnetic material, a rotor mounted on a shaft between said pole faces for limited rotary motion about an axis from a deenergized to an energized position, said rotor comprising a pair of semicircular rotor portions having their respective centers of curvature spaced equally on opposite sides of said axis, said centers of curvature and axis establishing three points on a common diameter of said rotor portions, the rotor portions being formed of a nonretentive magnetic material, adjacent arcuately configured pole faces and rotor portions forming a pair of arcuate airgaps therebetween, said airgaps diminishing in width from a maximum at one end to a minimum at the other end, the centers of curvature of said pole faces each being offset on an opposite side of said axis, the centers of curvature of said pole faces being coincident with the centers of curvature of adjacent rotor portions when said rotor is in an energized position, the radii of curvature of said rotor portions and the radii of curvature of said pole faces being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotor is in its said deenergized position and being contiguous to said curved pole faces when said rotor is in its energized position, and means for oppositely polarizing adjacent pole pieces and rotor portions.

Claim 7

A limited travel rotary electromagnetic actuator comprising a pair of spaced pole pieces having arcuately configured pole faces, said pole pieces being formed of a nonretentive magnetic material, a rotor mounted on a shaft between said pole faces for limited rotary motion about an axis from a deenergized to an energized position, said rotor comprising a pair of semicircular rotor portions having their respective centers of curvature spaced equally on opposite sides of said axis, said centers of curvature and axis establishing three points on a common diameter of said rotor portions, the rotor portions being formed of a nonretentive magnetic material, adjacent arcuately configured pole faces and rotor portions forming a pair of arcuate airgaps therebetween, said airgaps diminishing in width from a maximum at one end to a minimum at the other end, the centers of curvature of said pole faces each being offset on an opposite side of said axis, the centers of curvature of said pole faces being coincident with the centers of curvature of adjacent rotor portions when said rotor is in an energized position, the radii of curvature of said rotor portions and the radii of curvature of said pole faces being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotor is in its said deenergized position and being contiguous to said curved pole faces when said rotor is in its energized position, and means for oppositely polarizing adjacent pole pieces and rotor portions.

Claim 8

An electromagnetic actuator comprising a generally cylindrical housing having first and second pairs of spaced pole pieces secured thereto, a shaft journaled about a longitudinal axis of said housing for rotation therein, first and second rotors respectively mounted on said shaft between eacH of said pairs of spaced pole pieces to form first and second pairs of airgaps therebetween, said rotors being mounted for rotation from a deenergized position to an energized position, and means for oppositely polarizing adjacent pole pieces and rotors, each of said rotors comprising a first semicircular portion having its diameter in an axial plane and its center of curvature offset on one side of said axis, and a second semicircular portion also having its diameter in said axial plane and its center of curvature offset on the other side of said axis, said pole pieces being provided with curved pole faces disposed adjacent said rotor portions, the centers of curvature of said pole faces each being offset on an opposite side of said axis, the radii of curvature of said rotor portions being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotors are in their deenergized position and being contiguous to said curve pole faces with the centers of curvature of said curved pole faces coincident with the centers of curvature of adjacent rotor portions when said rotors are in their energized position.

Claim 9

An electromagnetic actuator comprising a generally cylindrical housing having first and second pairs of spaced pole pieces secured thereto, a shaft journaled about a longitudinal axis of said housing for rotation therein, first and second rotors respectively mounted on said shaft between eacH of said pairs of spaced pole pieces to form first and second pairs of airgaps therebetween, said rotors being mounted for rotation from a deenergized position to an energized position, and means for oppositely polarizing adjacent pole pieces and rotors, each of said rotors comprising a first semicircular portion having its diameter in an axial plane and its center of curvature offset on one side of said axis, and a second semicircular portion also having its diameter in said axial plane and its center of curvature offset on the other side of said axis, said pole pieces being provided with curved pole faces disposed adjacent said rotor portions, the centers of curvature of said pole faces each being offset on an opposite side of said axis, the radii of curvature of said rotor portions being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotors are in their deenergized position and being contiguous to said curve pole faces with the centers of curvature of said curved pole faces coincident with the centers of curvature of adjacent rotor portions when said rotors are in their energized position.

Claim 10

An actuator as in claim 6 wherein said housing, pole pieces, shaft and rotors are formed of a nonretentive magnetic material, and said means comprises a winding disposed around said shaft between said pole pieces.

Claim 11

An actuator as in claim 6 wherein each of the airgaps vary in width from a maximum at one end to a minimum at the other end.

Claim 12

A multiblade electromagnetic actuator driven shutter comprising a plurality of rotary electromagnetic actuators comprised of a plurality of pairs of spaced pole pieces, said pole pieces having curved pole faces, a plurality of polarizing coils for polarizing said pole pieces, and a plurality of rotors, one for each pair of pole pieces, mounted for rotation from a deenergized position to an energized position on a corresponding plurality of shafts about an axis between each of said pairs of spaced pole pieces, said pairs of pole pieces, polarizing coils and rotors defining a single closed magnetic path, each of said rotors having a first semicircular portion having its diameter in an axial plane and its center of curvature offset on one side of said axis, and a second semicircular portion also having its diameter in said axial plane and its center of curvature offset on the other side of said axis, the centers of curvature of said curved pole pieces each being offset on an opposite side of said axis, the centers of curvature of said pole faces being coincident with the centers of curvature of adjacent rotor portions when said rotors are in their energized position, the radii of curvature of said pole faces being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotor is in its said deenergized position and being contiguous to said curved pole faces when said rotors are in their energized position, and a plurality of interleaved shutter blades, one for each actuator, secured to said shafts for rotation therewith, whereby said shutter blades are adapted to open an aperture upon energization of said polarizing coils for exposing a web of light sensitive film.

Claim 13

A multiblade electromagnetic actuator driven shutter comprising a plurality of rotary electromagnetic actuators comprised of a plurality of pairs of spaced pole pieces, said pole pieces having curved pole faces, a plurality of polarizing coils for polarizing said pole pieces, and a plurality of rotors, one for each pair of pole pieces, mounted for rotation from a deenergized position to an energized position on a corresponding plurality of shafts about an axis between each of said pairs of spaced pole pieces, said pairs of pole pieces, polarizing coils and rotors defining a single closed magnetic path, each of said rotors having a first semicircular portion having its diameter in an axial plane and its center of curvature offset on one side of said axis, and a second semicircular portion also having its diameter in said axial plane and its center of curvature offset on the other side of said axis, the centers of curvature of said curved pole pieces each being offset on an opposite side of said axis, the centers of curvature of said pole faces being coincident with the centers of curvature of adjacent rotor portions when said rotors are in their energized position, the radii of curvature of said pole faces being substantially identical, the semicircular peripheries of said semicircular rotor portions extending arcuately throughout the extent of said curved pole faces when the rotor is in its said deenergized position and being contiguous to said curved pole faces when said rotors are in their energized position, and a plurality of interleaved shutter blades, one for each actuator, secured to said shafts for rotation therewith, whereby said shutter blades are adapted to open an aperture upon energization of said polarizing coils for exposing a web of light sensitive film.

Claim 14

An actuator driven shutter as in claim 9 wherein said pole pieces and rotors are formed of a nonretentive magnetic material, and said polarizing coils oppositely polarize the pole pieces in each pair of pole pieces and adjacent pole pieces and rotor portions.