(under subclass 17) Subject matter in which the space between the casing or jacket which encloses the envelope or the space between the double-walled envelope, includes means for preventing the flow of heat to or from the device.
SEE OR SEARCH THIS CLASS, SUBCLASS:
25+, where the space between the double walls or between the envelope and the casing or jacket is sealed off from the atmosphere and from the space within the envelope of the device. The sealed off space may be evacuated or filled with a gas or vapor. Note indented subclass 26 for discharge devices and lamps provided with an integral double-wall envelope.
SEE OR SEARCH CLASS
215, Bottles and Jars,
13.1, for receptacles of the bottle or jar type made of glass or other ceramic or similar material and having spaced walls with the interwall space containing a heat insulating means.
220, Receptacles, 2.1+, for double-walled envelopes designed for use for lamps and discharge devices, subclasses 415+ for miscellaneous receptacles having double-walls where the inner and outer walls are spaced apart and the intervening space contains a
