Improvements in or relating to pneumatic jordan operator with safety devices

摘要

760,529. Conical refiners. BOLTON & SONS, Inc., J. W. July 9, 1954 [Nov. 4 1953]; No. 20144/54. Class 59 Control apparatus for a conical refiner 20 for paper stock comprises an air supply motor 41 for advancing the plug 22 under constant pressure and a compression spring 50, Fig. 2, for retracting the plug, on substantial reduction or elimination of the air pressure, the supply of air to the motor 41 being controlled by an electrically operated twoway valve 57 which is moved to exhaust position in the event of de-energization of the electric motor 27 rotating the plug 22 or of the stock pump electric motor 35 or in the event of failure of the supply of stock entering the refiner. The motor 41 comprises a pair of flexible diaphragms 43, 44, Fig. 2, disposed in a casing 46, air under pressure being supplied to the space between the diaphragm via the valve 57 and a pipe 45. The operation of the valve 57 is controlled by a solenoid 72 contained in a circuit including four normally-closed automatic switches 80, 81, 82, 83 controlled by sensing devices B1, B2 , C1 , C2 responsive respectively to a reduction in the pressure of the stock supplied to the inlet 29 of the Jordan, a reduction in the level of the stock in a headbox 38, a failure in the circuit of the motor 27, and a failure in the circuit of the motor 35. The circuit may also include one or more manually operable switches 79. The sensing devices B1, B2 comprise respectively a resilient flexible diaphragm 91 inserted in the wall of the stock conduit 39 and connected to the contact arm 93 of the switch 80, and a float 87 connected to the contact arm 88 of the switch 81. The sensing devices C1, C2 comprise relays 95, 96 associated respectively with spring-influenced contact arms 101, 109 of the switches 82, 83. The headbox 38 may be omitted. The plug 22 is axially adjustable by means of a thrust screw 55, Fig. 2.