(under subclass 53) Subject matter wherein the resistor is of zigzag or helical type as defined in subclasses 283 and 296 respectively below, together with structure which transmits or facilitates the transmission of air or other gases to and into contact with the resistance element for cooling purposes.
(1) Note. The ventilating structure may be air passages or a particular spacing of the resistance element or parts thereof to facilitate air cooling. For classification here, the resistance element must be directly ventilated. A mere passage in a core or support for cooling purposes and not leading directly to the element, is not classified here, but in such subclasses as 53 and 55+, above.
SEE OR SEARCH THIS CLASS, SUBCLASS:
53, for resistors with ventilating passages or spaces generally. See also (1) Note above.
57, for a zigzag or helical resistor with a ventilating casing or housing, the zigzag or helical resistor also being ventilated.
283+, for resistors with zigzag or sinuous resistance elements generally. 296, for resistors with helical or wound resistance elements generally.
