| 摘要 |
<p>1,178,761. Machinery safety devices. PHILIPS GLOEILAMPENFABRIEKEN N.V. 17 Jan., 1967 [17 Jan., 1966], No. 1885/67. Heading F2J. [Also in Division E2] In a washing and centrifugal machine or dishwasher having a door giving access to a rotatable part which is adapted to be driven at two different speeds, an unlocking mechanism for the door comprises an electro-magnet and a centrifugal switch which opens the energizing circuit of the electro-magnet at the high speed of the rotatable part and closes it at the low speed of the part so that the door can only be opened when the magnet is energized. To start the machine, a push-button 9 is pressed to close a switch 10 and connect a driving motor winding 1 with mains terminals 11, 12. This is only possible if the door 8 is closed and locked, due to the presence of a micro-switch 13. The motor is coupled mechanically to a centrifugal switch 3 in the control circuit of an electromagnet, comprising a coil 4 and core 5, controlling an unlocking mechanism 14, 15, 16 for the door 8. A spring 22 holds the core 5 in the locking position when the electromagnet is not energized. In order to open the door 8, a push-button 7 is depressed so that push-button 9 returns to its initial position and the voltage supply to the motor is interrupted by switch 10 being opened. The centrifugal switch 3 is open whilst the machine is rotating at high speed, thereby preventing energizing of the coil 4 to unlock the door. At the lower speed of rotation, required for washing, the switch 3 is closed and the electromagnet energized thereby unlocking the door 8. Similarly the door may be opened when the machine is stationary. If the mains supply is cut-off, the mechanism may be unlocked by means of a screw-driver acting on a plate 19 coupled to core 5 by a cable 17 located in a housing 18.</p> |
