Electromagnetic indicator

Claim 2

An electromagnetic indicator comprising: a rotor support having a pair of spaced ears; a rotor having oppositely polarized permanent magnet poles, said rotor being disposed between said ears; said ears and rotor having cooperating means for releasably and rotatably mounting said rotor to said ears so that said permanent magnet poles reside in a common plane that extends tranversely of the axis of rotation of said rotor; first and second stop means on said rotor; a magnetic pole piece extending along said common plane and transversely of said axis of rotation, said pole piece extending close enough to said rotor to intercept (a) said first stop means when said rotor is rotated in a first direction and (b) said second stop means when said rotor is rotated in a second opposite direction, whereby to establish first and second limit positions respectively for said rotor; and electromagnetic field generating means for magnetizing said pole piece so as to magnetically influence said rotor to rotate to one or the other of said limit positions.

Claim 3

An indicator according to claim 1 wherein said electromagnetic field generating means comprises: a hollow bobbin surrounding a portion of said pole piece; a coil of electrically conductive wire wound around said bobbin; and terminal leads connected to the ends of said coil for coupling said coil to a source of electrical current, said ears being integral with said bobbin.

Claim 4

An indicator according to claim 1 wherein said ears are resilient and said cooperating means are adapted to provide a detent connection between said rotor and said ears.

Claim 5

An indicator according to claim 3 wherein said cooperating means comprises a pair of aligned pins on said rotor and a pair of aligned holes in said ears, said ears being spaced from one another so that they must be spread apart by flexing in order to insert said pins in said holes.

Claim 6

An indicator according to claim 3 wherein said pins are integral parts of said rotor.

Claim 7

An indicator according to claim 5 wherein said rotor comprises two parts secured together, with one of said pins formed integral with one of said parts and the other of said pins formed integral with the other of said parts.

Claim 8

An indicator according to claim 5 wherein said rotor has a circumferentially extending slot in its periphery, and further wherein said first and second stop means are surfaces at the opposite ends of said slot and said pole piece extends into said slot.

Claim 9

An indicator according to claim 1 further including: a plastic case enclosing said rotor, said ears, said pole piece and said electromagnetic field generating means; said rotor having indicia and at least a portion of said plastic housing being transparent so as to render one portion of said rotor viSible when said rotor is in said first limit position and a second portion of said rotor visible when said rotor is in said second limit position.

Claim 10

An electromagnetic indicator comprising: a one-piece plastic case open at one end and closed at its opposite end, said case being transparent at least at said opposite end; a combined coil and rotor support means comprising a hollow bobbin with a pair of spaced ears at one end of said bobbin, said coil and support means being disposed within said case with said ears located at said opposite end of said case, an elongate magnetic core member disposed within said bobbin, one end of said core member projecting between said ears; a rotor disposed between said ears, said rotor having two distinct indicia for indicating two different states of said indicator and a permanent magnet with salient magnetic poles at opposite sides of the axis of rotation of said rotor; means rotatably mounting said rotor to said ears; means for limiting rotation of said rotor between first and second limit positions; a coil of electrically conductive wire wound on said bobbin about said core member for producing when energized by an electric current a magnetic field that magnetizes said core member with a polarity determined by the direction of said current through said coil; terminal leads connected to the ends of said coil for energizing said coil with current from a selected source of current, said terminal leads projecting out of said one end of said case; and means sealing off said one end of said case.

Claim 11

An electromagnetic indicator comprising: a one-piece plastic case open at one end and closed at its opposite end, said case being transparent at least at said opposite end; a combined coil and rotor support means comprising a hollow bobbin with a pair of spaced ears at one end of said bobbin, said coil and support means being disposed within said case with said ears located at said opposite end of said case, an elongate magnetic core member disposed within said bobbin, one end of said core member projecting between said ears; a rotor disposed between said ears, said rotor having two distinct indicia for indicating two different states of said indicator and a permanent magnet with salient magnetic poles at opposite sides of the axis of rotation of said rotor; means rotatably mounting said rotor to said ears; means for limiting rotation of said rotor between first and second limit positions; a coil of electrically conductive wire wound on said bobbin about said core member for producing when energized by an electric current a magnetic field that magnetizes said core member with a polarity determined by the direction of said current through said coil; terminal leads connected to the ends of said coil for energizing said coil with current from a selected source of current, said terminal leads projecting out of said one end of said case; and means sealing off said one end of said case.

Claim 12

An indicator according to claim 9 wherein said rotor mounting means comprises cooperating relatively rotatable detent means on said ears and said rotor, said detent means being adapted to permit removal of said rotor by flexing said ears.

Claim 13

An electromagnetic indicator comprising in combination: a member comprising a hollow bobbin and a rotor support; a core of magnetic material within said bobbin; a coil wound on said bobbin and surrounding at least part of said core; a rotor rotatably mounted to said rotor support, said rotor being distinctively finished for visual indications of position and comprising a permanent magnet, said permanent magnet being magnetically coupled to said core so as to produce rotation of said rotor upon a change in the polarity of said core induced by energization of said coil; and a housing in which said member and rotor are disposed, said housing having end and side windows for viewing the presented distinctive surface of the rotor.

Claim 14

An electromagnetic indicator comprising in combination: a member comprising a hollow bobbin and a rotor support; a core of magnetic material within said bobbin; a coil wound on said bobbin and surrounding at least part of said core; a rotor rotatably mounted to said rotor support, said rotor being distinctively finished for visual indications of position and comprising a permanent magnet, said permanent magnet being magnetically coupled to said core so as to produce rotation of said rotor upon a change in the polarity of said core induced by energization of said coil; and a housing in which said member and rotor are disposed, said housing having end and side windows for viewing the presented distinctive surface of the rotor.

Claim 15

An indicator according to claim 11 wherein: said rotor support comprises a pair of spaced resilient ears formed integral with one end of said bobbin, and a hole in each ear; and further wherein said rotor comprises two identical halves secured together, each of said halves being formed with a pin at one side, said pins being mounted in the said holes in said ears.