GB722313A - Improvements relating to apparatus embodying vibrating or pulsating screens and the like - Google Patents

Abstract

722,313. Reciprocating machines. ROBERTS, E. G. L. Dec. 31, 1951 [Nov. 23, 1950], No. 28690/50. Class 35. An electromagnet vibrator comprises a fixedfield magnet energized by D.C. or A.C. or a permanent magnet and a reciprocating member actuated by a coreless moving coil which is energized by an intermittent or alternating current, the intermittence or periodicity being controlled to control the frequency of vibration. Fig. 1 shows a fixed-field system 1 and a moving coil 2 secured to a rod 3 which is coupled to another rod 6 to vibrate a member of an apparatus to be vibrated. Fig. 2 shows a screening apparatus having a table 8 which is pivotally mounted on four links 10 and adapted to be vibrated by the rod 6. The vibrated table 8 can be tuned by adjusting the compression of springs 16, 17 mounted between the table top and a fixed frame 9. The links 10 may be replaced by springs 26, Fig. 4 (not shown). Alternatively, the links 10 may be located on top of the table 8 and the springs 13 at the underside. Fig. 6 shows a feeder 27 supported on several springs 28 and vibrated by a number of vibrators 1. In another modification, a circular table 33, Fig. 7 (not shown), is directly connected to the vibrator 1 but supported by a number of coiled springs.