Abstract: An electrical heater device for heating a clinical mirror. The device comprises a housing having a top, bottom and side walls to define a hollow enclosure. Two spiral coiled electric heating elements are secured in the housing with their heat radiating surface spaced apart and facing each other in juxtaposition to provide concentrated heat in a mirror locating space therebetween. An opening is provided in the top wall in alignment with the mirror locating space through which the mirror can be inserted into the mirror locating space. A switch is positioned in alignment with the mirror locating space below the heating elements. The switch has an activating contact on an upper face thereof located in alignment with the opening in the top wall and the mirror locating space for activation by a clinical mirrow when the mirror element of such is inserted into the mirror locating space.

Abstract: A mirror unit suitable for exterior mounting on an automobile includes a glass member with a reflecting surface, a thermally-conducting metal plate, a self-regulating electrical resistance heater body of material of positive temperature coefficient of resistivity having one side mounted on one side of the plate in thermally and electrically conducting relation to the plate, terminal means electrically connected to the opposite side of the heater body, and means securing the plate to the glass member for enclosing the heater body therebetween to heat the glass member for defogging the reflecting surface thereof.

Abstract: A magnifying lens incorporated in an endoscope optical system for viewing an illuminated area to be examined by means of the endoscope is adjustable between end positions in which it lies behind and in front of the focus of the optical system respectively, whereby to enable general examination of said area at a relatively small magnification and a more detailed examination of said area at a relatively higher magnification. A viewing window of an endoscope optical system is heated by an electrical heating conductor to guard against clouding of the viewing window, for example by the breath of a patient.

Abstract: The specification discloses a defrosting mirror especially adapted for outdoor use such as on the exterior of vehicles. The mirror includes an electrically conductive, resistive coating applied to a surface of a light reflective mirror element. The coating includes micro-sized graphite particles dispersed throughout a resinous binder material such that electricity flows through the coating to generate heat which is transferred to the mirror element. A resinous primer layer intermediate the coating and mirror element bonds the coating to the mirror element for retention of the conductive, resistive coating especially when the mirror is exposed to humidity, salt spray, or other environmental or weather conditions.

Abstract: An electrically conductive product generally comprised of a substrate or web coated with or impregnated with an electrically conductive thermally stable material which includes a special polymeric binder and conductive particles to produce the final conductive sheet.

Abstract: An anti-condensation device having an electric heating element and method whereby said heating element is woven horizontally on an insulation plate and is sufficiently enlarged at the central portion to cause the temperature to be the same at every portion of the mirror face of the mirror in which it is used, and because of the heat produced by the heating element and conducted to the face of the mirror, when this mirror is installed in a bathroom or place where there is much steam and vapor, there is a method to cause the temperature of the reflective surface of said mirror to be 7.degree.-10.degree. C (18.degree. F) higher than that of temperature of the room or the adjacent atmosphere, so that it is possible to prevent water vapor dispersed in the air from condensing on the reflective surface of the mirror.

Abstract: A generally horizontal and cylindrical hollow housing is provided for mounting slightly outward of the upper marginal edge portion of a bathroom mirror and the housing includes an elongated entrance slot formed in one side thereof for opening toward the adjacent mirror as well as a second longitudinal outlet slot circumferentially spaced from the inlet slot in a manner to open inwardly toward and downwardly along the associated bathroom mirror. A motor driven blower wheel or drum is rotatably journaled in the housing in a manner so as to draw ambient air into the housing through the inlet slot and exhaust air outwardly from the housing through the outlet slot downwardly along the space of the associated mirror for the purpose of maintaining the latter free of condensation thereon, even when the conditions for the formation of condensation on the mirror are excessive.

Abstract: A highway sign machine adapted to be mounted in an overhead position proximate to a traffic lane operates under local or remote control to dis play selectively to motorists any of a plurality of written traffic messages on a vertical sign face covering the front profile of the machine and virtually duplicating the appearance of standard overhead signs for expressways that continuously display unchanging messages. A plurality of traffic messages are written longitudinally on angularly spaced message faces on rotors that are rotatably indexed to different message presenting positions where the rotors are accurately located and releasably held by rotary cam and follower means against vibration. Replaceable message panels on the rotors are supported by lightweight structure resistant to bending and vibration and comprising extruded corner chords having tubular bodies and integral flanges connected by diagonal webs underlying the message panels.

Abstract: A grid of heating conductors for defrosting applied to the window of a vehicle is connected to a source of electrical energy through a relay-operated switch. This switch is closed either in response to a drop in the resistance between two conductors or electrodes mounted in spaced relation on an insulating support such as the window (the drop occurring by accumulation of moisture on the support and between the conductors) or in response to a drop in temperature at or near the window. For this purpose the resistance between the two conductors over the surface of the support may be paralleled by a thermostatic switch which closes with drop in temperature, both this resistance and the thermostatic switch being in the input to a trigger circuit controlling the relay to energize it in response to a decline in resistance at that input. Alternatively the trigger circuit may include thermistors which sense the drop in temperature and set the trigger circuit to the condition which energizes the relay.