GB909433A - Automatic hot air sterilizer - Google Patents

Abstract

909,433. Sterilizers. CHIRANA PRAHA NARODNI PODNIK. Aug. 30, 1960 [Aug. 31, 1959], No. 29803/60. Class 81 (1). An automatic hot air sterilizer comprises a sterilizing space 11, electrical heating elements 1 located below the space, a thermostat 7 controlling the energization of the elements, a circulator 3 located outside the sterilizing space, and causing air to flow from the sterilizing space over the heating elements and then through a lateral conduit 5 over the feeler of the thermostat, and hence through an upper conduit 6 and through openings 9 in the upper wall of the sterilizing space back into the sterilizing space. Provision is made for automatic timing of the net sterilizing time, that is excluding the time required for heating up the apparatus, and for visual and audible indication of the various operating phases. In operation, after adjustment of the temperature at which sterilization is required on a selector, and adjustment of the necessary sterilizing time on the time switch, the master switch is switched on, the apparatus itself switching on the heating and air circulation and an indicator light marked " Operating " and another indicator light marked " Heating " are lit. As soon as the required temperature is reached, the thermostat begins to control the heating elements by intermittently switching them on and off so that the temperature variations are kept within admissible limits, the indicator light marked " Heating " being also intermittently switched on and off. The time switch now begins to measure the net sterilizing time by means of a rotating arm on a dial, after completion of which the net heating and circulation are automatically stopped, but the light marked " Operating " remains lit, and a buzzer gives an audible signal which can be stopped by depressing a button. By opening the master switch, the light marked " Operating " is also extinguished and the whole apparatus is put out of operation.