GB1322178A - Vibratory drives - Google Patents

Abstract

1322178 Vibratory conveyers NJ MURRELL 19 April 1971 [3 Dec 1969 15 Dec 1969] 58916/69 and 61034/69 Heading B8A [Also in Division H2] A drive unit for a vibratory conveyer comprises a reciprocable drive member 16 resiliently mounted on a housing 12 containing an electromagnetic motor 13 and a transducer 25 responsive to movement of the member 16 for generating a signal which controls the power supply to the motor. As shown in Fig. 1, the motor comprises a pair of coils (15) carried by a U-shaped core (14) co-operating with a permanent magnet armature 18 carried by member 16. The latter is mounted on inclined leaf springs 17 which impart a rotary component to the reciprocating movement of the member. The transducer comprises a coil 26 mounted in the housing at a position in which the field intensity from the motor coils (15) is a minimum and cooperating with a further permanent magnet 27 carried by member 16. Alternatively the transducer may comprise a photo-electric, straingauge, Hall-effect or piezo-electric device. Member 16 is shown coupled to a feed bowl 20 having a convex base on which objects fed from a hopper progress outwards to a helical feed track 22 extending round the wall 21 of the bowl to a discharge gate 23. In one form of control circuit for the motor, Fig. 3 (not shown), pulses generated by the transducer coil 26 are fed via a pre-amplifier (32) and pulse-shaper (33) to the input of a power amplifier (34) which also receives power from a main supply (35) whereby the power amplifier delivers pulses to the motor 13 which are phase and frequency locked to the signal from coil 26. Amplitude control means (36) are provided in the power-supply to adjust the supply to motor either automatically according to load or manually. Fig. 4 shows an alternative control circuit in which the pulses from coil 26 are fed to a trigger circuit 37 which controls, under the influence of the amplitude control 39, a gating circuit 38 in turn controlling the supply to the motor from source 35. Both circuits may include means for controlling the supply of objects to the feed bowl from a hopper.