Hall effect rotary pulse generator

Claim 1

A rotary electrical pulse generator comprising a rotor with a rotor shaft and a spool magnet subassembly with a non-magnetic hub fixed onto the rotor shaft intermediate the ends thereof having reduced end portions and an intermediate annular flange portion and a pair of substantially identical magnet rings fixed coaxially onto the reduced end portions of the hub in engagement with the annular flange portion which thereby establishes a fixed axial air gap between the magnet rings, each magnet ring being axially magnetized to have an even plurality of equiangularly spaced inner permanent magnet poles of alternating magnetic polarity, the pair of magnet rings being mounted on the hub with their respective permanent magnet poles in substantially axially aligned magnetic attraction whereby an annular alternating magnetic field is produced in the air gap between the magnetic rings; a support block having a first upright mounting aperture, a first upwardly opening pocket at the upper end of said first mounting aperture for receiving the spool magnet subassembly and a second downwardly opening pocket at the lower end of the first mounting aperture, an upper cantilever arm mounted on the support block to extend over the first pocket, the cantilever arm having a second mounting aperture in axially spaced alignment with the first mounting aperture, rotor support bushings mounted within the aligned apertures receiving the rotor shaft for rotatably supporting the rotor upright on the support block, an upper retaining ring mounted on the upper end of the rotor shaft above the cantilever arm for retaining the rotor against downward axial movement on the block, a combination gear and brake drum member fixed onto the lower end of the rotor shaft below the first aperture having a lower spur gear portion and an upper brake drum portion with an outer brake drum surface received in the second pocket, the second pocket having a pair of diametrically opposed generally V-shaped pocket portions each having a pair of angularly related leg pockets extending generally tangentially from the outer brake drum surface to form two pairs of diametrically opposed leg pockets, a pair of locking elements in the leg pockets of one of said pairs of diametrically opposed leg pockets in engagement with the brake drum surface, each pair of diametrically opposed leg pockets having outer sidewalls for wedging the locking elements against the brake drum surface for preventing rotation of the rotor in one angular direction, and compression springs in said one pair of leg pockets biasing the locking elements into engagement with the brake druM surface and the respective outer sidewalls, the combination gear and brake drum member retaining the rotor against upward axial movement on the block and having an annular flange for retaining the locking elements and compression springs within the leg pockets, the block having a pair of diametrically opposed slots extending radially outwardly from the first pocket, a pair of Hall probes mounted in the slots to extend within the air gap to be acted upon by the alternating magnetic field to generate substantially equally spaced pulses as the rotor rotates, and a plurality of electrical terminal posts mounted on the block and connected to the Hall probes to provide for electrical connection to the rotary pulse generator.