Signal generating mechanism

Claim 2

A signal generating mechanism for producing an alternating electrical signal having a frequency proportional to the angular velocity of a rotating shaft, said signal generating mechanism comprising, in combination: a lower plate fixed relative to said rotating shaft, said lower plate having an opening therein; an annular bushing affixed in said lower plate opening, said bushing extending above said lower plate, said shaft passing through said bushing; a stator assembly, said stator assembly including an annular hub positioned around the portion of said bushing extending above said lower plate, said hub being rotatable about said bushing, an upper plate parallel to said lower plate and affixed to said hub, a permanent magnet attached to said upper plate, said magnet being polarized to produce a magnetic field having a direction through said magnet that is perpendicular to said upper plate, a stator positioned on said permanent magnet, said stator having a pole-piece, and an electrical coil positioned on said stator pole-piece; and a rotor attached to said shaft for rotation therewith, said rotor having at least one tooth positioned to come into and go out of alignment with said stator pole-piece; whereby rotation of said rotor produces an alternating electrical signal across the terminals of said electrical coil having a frequency proportional to the angular velocity of said rotating shaft.

Claim 3

A signal generating mechanism for producing an alternating electrical signal having a frequency proportional to the angular velocity of a rotating shaft, said signal generating mechanism comprising, in combination: a lower plate fixed relative to said rotatiNg shaft, said lower plate having an opening therein; an annular ferromagnetic bushing affixed in said lower plate opening, said bushing extending above said lower plate, said shaft passing through said bushing; a stator assembly, said stator assembly including an annular ferromagnetic hub positioned around the portion of said bushing extending above said lower plate, said hub being rotatable about said bushing, a ferromagnetic upper plate parallel to said lower plate and affixed to said hub, a permanent magnet polarized to produce a magnetic field having a direction through said magnet that is perpendicular to said upper plate, a ferromagnetic stator positioned on said permanent magnet, said stator and said permanent magnet being non-adjustably secured to said upper plate, said stator having a pole-piece extending radially towards said shaft axis, and an electrical coil positioned on said pole-piece, said pole-piece extending through said electrical coil; and a ferromagnetic rotor affixed to said shaft for rotation therewith, said rotor having a plurality of teeth positioned to come into and to go out of alignment with said pole-piece of said stator during rotation of said shaft; whereby rotation of said shaft produces an alternating signal across the terminals of said electrical coil.

Claim 4

A signal generating mechanism for producing an alternating electrical signal having a frequency proportional to the angular velocity of a rotating shaft, said signal generating mechanism comprising, in combination: a lower plate fixed relative to said rotatiNg shaft, said lower plate having an opening therein; an annular ferromagnetic bushing affixed in said lower plate opening, said bushing extending above said lower plate, said shaft passing through said bushing; a stator assembly, said stator assembly including an annular ferromagnetic hub positioned around the portion of said bushing extending above said lower plate, said hub being rotatable about said bushing, a ferromagnetic upper plate parallel to said lower plate and affixed to said hub, a permanent magnet polarized to produce a magnetic field having a direction through said magnet that is perpendicular to said upper plate, a ferromagnetic stator positioned on said permanent magnet, said stator and said permanent magnet being non-adjustably secured to said upper plate, said stator having a pole-piece extending radially towards said shaft axis, and an electrical coil positioned on said pole-piece, said pole-piece extending through said electrical coil; and a ferromagnetic rotor affixed to said shaft for rotation therewith, said rotor having a plurality of teeth positioned to come into and to go out of alignment with said pole-piece of said stator during rotation of said shaft; whereby rotation of said shaft produces an alternating signal across the terminals of said electrical coil.

Claim 5

The signal generating mechanism of claim 2 wherein a gap exists between a tooth of said rotor that is in alignment with said pole-piece, said gap being within the dimensional range from 0.062 of an inch to 0.023 of an inch.

Claim 6

A signal generating mechanism for producing an alternating electrical signal, which comprises, in combination: a housing; a shaft rotatably journalled in said housing; a lower plate secured to said housing, said lower plate having an opening therein and being positioned perpendicular to said shaft; a ferromagnetic bushing affixed in said lower plate opening, said bushing extending above said lower plate and having lubrication grooves on the radially exterior portion thereof, said shaft passing through said bushing; a ferromagnetic sleeve on the portion of said shaft passing through said bushing, said sleeve being rotatable about said shaft; a centrifugal mechanism interconnecting said sleeve and said shaft for controlling rotation of said sleeve about said shaft; a toothed ferromagnetic rotor secured to said sleeve for rotation therewith, the teeth of said rotor extending radially outward from the axis of said shaft; a stator assembly, said stator assembly including an annular ferromagnetic hub positioned around the portion of said bushing extending above said lower plate, said hub being rotatable about said bushing, a ferromagnetic upper plate parallel to said lower plate and affixed to said hub for rotation therewith, an arcuately-shaped permanent magnet positioned on said upper plate, said permanent magnet having a north pole and a south pole, an imaginary line interconnecting said north and south poles being perpendicular to said upper plate, said permanent magnet being made from a ceramic ferrite material, a ferromagnetic stator positioned on said permanent magnet, said stator and permanent magnet being non-adjustably secured to said upper plate, said stator having a pole-piece positioned to permit said rotor teeth to come into and to go out of alignment with it, and an electrical coil surrounding said pole-piece of said stator, said electrical coil being helically wound and having an axis perpendicular to the axis of said shaft; and means connected to said upper plate of said stator assembly for controlling the rotation of said stator assembly about said bushing.

Claim 7

A signal generating mechanism for producing an alternating electrical signal, which comprises, in combination: a housing; a shaft rotatably journalled in said housing; a lower plate secured to said housing, said lower plate having an opening therein and being positioned perpendicular to said shaft; a ferromagnetic bushing affixed in said lower plate opening, said bushing extending above said lower plate and having lubrication grooves on the radially exterior portion thereof, said shaft passing through said bushing; a ferromagnetic sleeve on the portion of said shaft passing through said bushing, said sleeve being rotatable about said shaft; a centrifugal mechanism interconnecting said sleeve and said shaft for controlling rotation of said sleeve about said shaft; a toothed ferromagnetic rotor secured to said sleeve for rotation therewith, the teeth of said rotor extending radially outward from the axis of said shaft; a stator assembly, said stator assembly including an annular ferromagnetic hub positioned around the portion of said bushing extending above said lower plate, said hub being rotatable about said bushing, a ferromagnetic upper plate parallel to said lower plate and affixed to said hub for rotation therewith, an arcuately-shaped permanent magnet positioned on said upper plate, said permanent magnet having a north pole and a south pole, an imaginary line interconnecting said north and south poles being perpendicular to said upper plate, said permanent magnet being made from a ceramic ferrite material, a ferromagnetic stator positioned on said permanent magnet, said stator and permanent magnet being non-adjustably secured to said upper plate, said stator having a pole-piece positioned to permit said rotor teeth to come into and to go out of alignment with it, and an electrical coil surrounding said pole-piece of said stator, said electrical coil being helically wound and having an axis perpendicular to the axis of said shaft; and means connected to said upper plate of said stator assembly for controlling the rotation of said stator assembly about said bushing.

Claim 8

The signal generating mechanism of claim 4 wherein a gap exists between a tooth of said rotor that is in alignment with said pole-piece, said gap being within the dimensional range from 0.062 of an inch to 0.023 of an inch.