Patent ID: 6136280
Filing Date: 2000-10-24
Classification: A61L

Abstract:
An autoclave type sterilization device which includes:an autoclave chamber for sterilization of objects when suitable liquid introduced therein is brought to suitable temperature and pressure,at least one electrical heating device arranged in thermal contact with the outer surface of said autoclave chamber; andmounting means for positioning said at least one electrical heating device on said outer surface of said autoclave chamber and for maintaining thermal contact therebetween;wherein said at least one electrical heating device includes:at least one positive temperature coefficient (PTC) thermistor heating element having generally parallel, flat, contact surfaces;a pair of plate members formed of an electrically insulating and thermally conductive material having generally parallel, flat, inward- and outward-facing contact surfaces and wherein said inward-facing contact surfaces are coated with a thermally and electrically conductive metal;a pair of heat radiation members formed of an electrically and thermally conductive material, whereinfirst heat radiation member includes:an enclosing portion surrounding said at least one positive temperature coefficient (PTC) thermistor heating element on their sides other than their generally parallel, flat, contact surfaces anda heat transfer portion having a generally flat, inward-facing, contact surface for thermally conductive contact with the first of said outward-facing contact surfaces of said plate members and with an outward-facing contact surface fabricated to engage a portion of said outer surface of said autoclave chamber for thermally conductive contact thereby to define a thermal interface therewith; andsecond heat radiation member comprises:a plate portion having a generally flat, inward-facing, contact surface for thermally conductive contact with the second of said outward-facing contact surfaces of said plate members andat least one heat transfer portion with outward-facing contact surfaces fabricated to engage portions of said outer surface of said autoclave chamber for thermally conductive contact thereby to define thermal interfaces therewith;electrode means disposed about said at least one heating element operative to provide thermally and electrically conductive contact with said contact surfaces thereof and thermally conductive contact with said inward-facing contact surfaces of said plate members;means for fastening said heat radiation members about said plate members such that said inward-facing, contact surfaces of said plate portions are held in thermally conductive contact with said outward-facing contact surfaces of said plates members thereby to define therewith thermal interfaces,said means for fastening being further operative to fasten said plate members about said electrode means and said electrode means about said at least one heating element such that said inward-facing, contact surfaces of said plate members are held in electrically and thermally conductive contact with said electrode means and said electrode means are held in electrically and thermally conductive contact with said flat contact surfaces of said at least one heating element thereby to define therewith thermo-electric interfaces;enclosing means formed of an electrically and thermally insulating material and formed for positioning around said at least one heating element and between said plate portions of said heat radiation members so as to prevent a flow of gas from coming into contact with said at least one heating element; andterminal means attached to said electrode means, operative to permit flow of electric current therethrough, across said interfaces, and via said at least one heating element, thereby producing thermal energy therein;wherein, when an electrical current passes through said electrical heating device, thermal energy from said at least one heating element is conducted across said interfaces to said heat radiation members and thereby to said autoclave chamber thereby heating the contents thereof.