US2457353A

US2457353A - Quartz lamp assembly

Info

Publication number: US2457353A
Application number: US607867A
Authority: US
Inventors: Raymond R Davis
Original assignee: PARAGON REVOLUTE CORP
Current assignee: PARAGON REVOLUTE Corp
Priority date: 1945-07-30
Filing date: 1945-07-30
Publication date: 1948-12-28
Anticipated expiration: 1965-12-28

Description

Dec. 28, 1948. R. R. DAVIS 2,457,353

QUARTZ LAMP ASSEMBLY Filed July 30, 1945 IN VEN TOR. Q Rmwo/vo R. paws HTTORNEY Patented Dec. 28, 1948 QUARTZ LAMPASSEMBLY Raymond E. Davis, Rochester, N. Y., asslgnor to i-Paragon Revolute Corporation,

Rochester,

N. Y., a corporation of New York Application July 30, 1945, Serial No. 607,867

3 Claims. (Cl. 176-122) i This invention relates tea light source for use in machines utilized for the exposure of photosensitive sheets.

In machines of this k nd and particularly in machines of the type illustrated in the Sullivan Patent 2,093,785, the photosensitive sheet or paper to be exposed, travels around a rotating cylinder of Pyrex glass having therein a light source extending along its principal axis. This light source in certain machines is preferably in the form of a high pressure mercury quartz lamp. Such a lamp generates harmful ultraviolet light waves and also generates considerable heat which, unless dissipated or diverted tends to shorten the life of the lamp.

The main feature of the present invention relates to a novel quartz lamp assembly in which the lamp is mounted within a transparent enclosure in such a manner as to filter out harmful ultraviolet light waves and in such a manner as not to shorten the life of the lamp.

Another feature of the invention relates to the novel arrangement for mounting of a quartz lamp within a transparent enclosure.

These features and others will appear from the detailed description and claims when taken with the drawing in which the single view is a side elevation of the lamp assembly of the present invention with parts thereof broken away.

In the drawing, the numeral 5 designates a cylindrical quartz tube of a high pressure mercury quartz lamp. This tube terminates at each end in a vacuum seal 6 through each of which seals there extends axially, a starting electrode 7, only the left end electrode being shown. The tube after being carefully evacuated is filled with a starting gas such as argon and with a few mercury droplets. Each electrode is connected to an insulated conductor 8, which conductors are connectable to a suitable electrical energizing source. Each end of the tube is provided with an end cap 9 provided with a peripheral flange 9a.

The quartz lamp is supported coaxially within a cylindrical Pyrex glass envelope it which is open at each of its flared ends. The Pyrex glass enveloped is provided primarily to assure the proper operating temperature for the quartz lamp since it has been found that with such proper operating temperature, the life of the lamp is greatly prolonged. The glass envelope also serves to confine objectionable ozone fumes since Pyrex glass, while it is highly transmittent to long ultraviolet rays important to printing, completely absorbs the short ultra-violet waves which generate ozone from the air.

The lamp at each of its ends is supported within the enveloped by a set of annular supports ll of mica or the like, the center openings through which are of a size to receive the end cap 9 mounted on the end of the quartz lamp. The diameters of these supports are such that they engage the inner surface of the envelope it.

Each end of the envelope is closed by a Pyrex glass end cover comprising a head it and a reduced .neck it. The neck i5 is of such length that the mica supports it and washer it are snugly held against the flange 9a. on the cap when the head M of the cover engages its related flared end of the envelope. Each head is provided with a ventilating hole l6 and with an aperture ll. Insulating beads It with suitable asbestos string l9 close the aperture ll, and provide protective insulation for each conductor 8.

Each end cover is held in place by clamping means. This clamping means comprises a split ring 20 embracing a flared end of the envelope. The ring is provided with diametrically loc'ated ears 2i, each of which has pivotally supported thereon, a metal strip 22 shaped to extend over the head it where the perforated free ends of the adjacent pair of strips, receive a bolt 23 to clamp the strips together.

The lamp assembly is preferably mounted within the printing machine on spaced brackets 24.

The assembly of the present invention provides an arrangement wherein a glass envelope filters out the harmful short ultraviolet light waves generated by the quartz lamp and wherein the lamp is supported in a way to greatly prolong the life thereof.

What I claim is:

i. In a quartz lamp assembly, a lamp comprising a closed quartz tube having an ionizible medium therein, each end of said tube being provided with a vacuum seal having an electrode sealed therein to project into the tube, a conductor connected to each electrode externally of said tube, a shield comprising a cylinder of material having the property of passing long ultraviolet rays therethrough and of preventing the passage therethrough of short ultraviolet rays such as generate ozone from the air, said cylinder being open at both of its ends, said shield also comprising removable ventilating covers closing the open ends of said cylinder, and mica-like supporting means engaging the inner surface of each end of the cylinder, said supporting means also engaging each end of the tube.

2. In a quartz lamp assembly, a lamp comprising a closed quartz tube having an ionizible meproperty of passing long ultraviolet rays thereductor connected to each electrode externally oi said tube, a shield comprising a cylinder of material having the property of passing long ultraviolet rays therethrough and of preventing the passage therethrough of short ultraviolet rays such as generate ozone from the air,said cylinder being open at both of its ends, said shield also comprising covers having necks fitting into the respective open ends 01 said cylinder to close the same, and supporting means having the periphery thereof engaging each end of the cylinder, said supporting means being held in position by the respective ends of said covers and engaging the periphery of each end of the tube.

3. In a quartz lamp assembly, a lampvcomprising a closed quartz tube having an ionizable medium therein, each end oi said tube being provided with a vacuum seal having an electrode sealed therein to project into the tube, a conductor connected to each electrode externally of said tube, a flange cap carried by the tube and encircling each electrode adjacent its seal, a shield comprising a cylinder of material having the through and oi preventing the passage therethrough of short ultraviolet rays such as generate ozone from the air, said cylinder being open at both 'of its ends, said shield also comprising covers having necks fitting into the respective open ends of said cylinder to close the same, and supporting means having portions thereof engaging each end or the cylinder, said supporting means engaging portions of each end of the tube and being held by the respective ends ofsaid covers and by the respective flanges.

RAYMOND R. DAVIS.

REFERENCES CITED The following references are of record in the me of this patent:

UNITED STATES PATENTS