GB713025A - Improved apparatus for anaesthetising living organs, more particularly teeth, by means of cold air - Google Patents

Abstract

713,025. Anaesthetic apparatus. SCHAAF, W. Oct. 24, 1951 [March 19, 1951], No. 24870/51. Class 81(2) In an apparatus for anaesthetizing by freezing air is passed through a heatexchanger coupled to a refrigerating machine so that it is cooled, preferably below freezing point, and it is then directed on to the part to be treated through a nozzle in a handpiece. In one form of the apparatus air from a pump 21, Fig. 5, passes through a chamber 25, enclosing an ultra-violet lamp 30, in order tosterilize it, and thence to a coil 34 contained in a fluid 35 which is kept cool by a heat-exchanger device 37 connected to a refrigerator 38. The cooled air passes out through a flexible pipe to a handpiece 42. The handpiece contains a thermometer 43 having electrical contacts which, by breaking the circuit of a relay 45, when the temperature reaches -4 ‹C, switches on a heating wire 39. An inspection lamp 47 is also provided. Any moisture which condenses as a result of the compression of air by the pump 21 is collected in a tube 33 and subsequently drawn off. The upper part of the sterilizing chamber, above an air tight partition 27, encloses an infra-red' lamp 28 and is intended to receive instruments &c. The handpiece shown in Fig. 2, has a valve 14 for controlling the flow of air and a contact operating plunger 16 for switching on a local heating coil 15 when, required.