(under subclass 17) Devices in which the space between the double wall envelopes or between the envelope and the casing or jacket is sealed off from the atmosphere and from the space within the envelope of the lamp or discharge device.
(1) Note. This subclass includes electric lamps whether of the discharge device type or not, photosensitive discharge devices, generators of invisible ray energy (e.g., X-ray tubes, ultraviolet lamps, etc..) only when the casing or jacket is integrally united with the envelope of the device. See (1) Note to the definition of subclass 11 with respect to the classification of such subject matter where the casing or jacket is not integrally united.
SEE OR SEARCH THIS CLASS, SUBCLASS:
27, for other discharge devices and lamps which are provided with a double wall envelope or which have a jacket or casing for the envelope of the device, the space between the envelope walls or between the casing or jacket and the envelope containing a heat conserving or heat insulating material.
312, and the subclasses specified in the notes thereto, for miscellaneous and discharge devices which are provided with an envelope and a casing or jacket for the envelope.
317+, for miscellaneous lamps and discharge devices which are provided with a double-wall envelope where the heat transmitting properties of the double wall envelope are not involved.
