GB978144A - Electrical supervisory apparatus for a centrifuge - Google Patents

Abstract

978,144. Control devices for centrifuge covers. W. KRANTZ, [trading as H.KRANTZAACHEN]. April 24, 1963 [May 12, 1962], No. 16191/63. Heading B1D. The housing cover of a centrifuge is locked, released and/or opened by means of electrical apparatus comprising a permanent magnet 3 which is rotatable with the centrifuge drum 2 and may be situated on the edge thereof, an induction coil 6 which pass the pulses generated by the movement of magnet 3 to an amplifier 7 and on to a thyratron 8 which is adapted to be quenched upon receiving a pulse from the induction coil and to remain quenched as long as pulses follow one another in a sufficiently dense series to prevent a relay 9 which controls the locking, releasing and/or opening of the housing cover from becoming actuated until the centrifuge slows down, e.g. on braking. Thus relay 9 operates the switch 10 which when drum 2 is rotating switches on the circuit 11 for the locking magnet of the cover and a pilot lamp circuit 12, and when the drum is at rest, breaks the circuits 11 and 12 and closes circuit 13 which allows compressed air to enter a pressure cylinder for opening the cover. The Specification refers to German Specification 922,580 which discloses a device wherein the cover of the centrifuge is released by a magnet which is controlled by a time responsive relay. The relay may be delayed in its action by current pulses from a pulse generator. The pulse generator may take two forms. It may be a contact roller or disc mounted on the shaft of the centrifuge drum and in contact with brushes which are connected to the relay. Alternatively, the pulse generator may be a transformer in which the magnetic flux is interrupted by an armature arranged on the end of the shaft of the centrifuge.