(under subclass 53) Subject matter including a casing or housing of solid material which substantially entirely encloses the resistance element, the casing or housing having openings therein joining the resistance element with the surrounding medium to permit circulation of air or other gases to and from the resistance element.
(1) Note. The subject matter here is restricted to casings with vents or other openings transmitting air or other gases. Subclasses 55+ provides for resistors with casings and liquid cooling. Further the air or gas must be free to circulate for classification here. Subclasses 234+ provides for an incased, embedded or housed resistor with a gaseous or vacuum spacing between the element and casing or housing without the ventilation or cooling. The ventilation may be forced as by a fan as well as naturally for classification here. Subclasses 226+ below provides for resistors generally with casings or housings which transmit heat through the material to the casing or housing. A mere open ended sleeve surrounding the resistance element is not sufficient to constitute a vented casing for classification here, but rather is classified in subclass 53 above, if air circulation is present.
SEE OR SEARCH THIS CLASS, SUBCLASS:
51+, for resistors with heat dissipating projections, e.g., vanes.
53+, for resistors with ventilating passages or spaces
generally. See also (1) Note above.
55+, for incased resistors with a liquid cooling medium. See also (1) Note above. 234+, for incased, embedded or housed resistors generally with a gaseous or vacuum spacing between the element and the casing or housing. See also (1) Note above.
277, for resistors with protecting structure such as guards, screens, and mechanical shields.
SEE OR SEARCH CLASS
174, Electricity: Conductors and Insulators,
16.1, for a mere housing or casing for an electrical device with means to provide for ventilation of the interior of the casing.
219, Electric Heating,
280+, for fluid resistance heaters. See also (1) Note under subclass 53 above.
312, Supports: Cabinet Structure,
213, for enclosures with ventilated openings not otherwise classifiable.
336, Inductor Devices,
59, for inductors with vented casings.
454, Ventilation, appropriate subclasses, for ventilating structure such as cowls, hoods and louvers.
