US2288253A - Introducing mercury into vacuum devices - Google Patents

Description

June 30, 1942. E. A. REUTER I INTRODUCING MERCURY INTO VACUUM DEVICES Filed June 21, 1941 m L N WM Mm V T W N M Patented June 30, 1942 TET OFFICE Edmund A. Renter, East Orange, N. J., assignor to Westinghouse Electric in Manufacturing Company, East Pittsburgh, Pa, a corporation of Pennsylvania Application June 21, 1941, Serial No. 399,059

'7 Claims.

My invention relates to discharge devices, and especially to introducing mercury or other gaseous vapor into the container of such discharge devices.

An object of the invention is to introduce a predetermined amount of mercury or other gaseous medium into a discharge device. Heretofore, the required amount of mercury has been distilled into discharge devices, such as lamps and electronic devices during manufacture or an excess of mercury has been introduced into the lamp and the excess boiled out until the required amount is left.

My invention is a means of introducing measured amount of mercury into a lamp or electronic device without the disadvantages of these older methods.

In particular, I incorporate the mercury or other gaseous medium in a sealed container inserted in the assembled tube and then release the mercury or other vapor by the use of high frequency after the tube has been pumped out and sealed off.

In particular, my invention permits the ready release of the mercury at the desired time and my preferred embodiment prevents any contamination of air in the mercury introduced into the tube.

Other objects and advantages of my invention will be apparent from the following description and drawing in which:

Fig. l is a partial view of one end of a sterilizing lamp in which a preferred embodiment of my invention has been incorporated.

Fig. 2 is an enlarged view of the mercury container illustrated in Fig. 1.

Fig. 3 is a cross sectional view on lines IIIIII of Fig. 2.

Fig. 4 is a longitudinal cross section of one end of the mercury container of Fig. 2.

Fig. 5 is a modification of the form of container illustrated in Fig. 2.

Figs. 6 through 12 are respectively still further modifications of my invention.

In Fig. l I have illustrated one end of a sterilizing lamp to which my invention has been applied. This lamp includes a glass casing II] having a press II at one end through which extends the conductor I2 to the electrode l3. A conductor I6 is connected to a standard I! coated with glass insulation l8 and passes upward to an electrode, not shown, but similar to E3 and cooperating therewith.

, In order to introduce the mercury into the device at the proper time, I provide a container 25! which is more fully illustrated in Fig. 2. This container is welded to a rod 2| welded in turn to one of the fins 22 at the base of the electrode l3. The mercury container 20 is preferably supported adjacent the press I l,wh'e re it can be conveniently flashed by a high frequency coil 23 surrounding the tube at the location of the mercury container 29.

The mercury container 20 is a length of seamless metal tube, preferably nickel, with an outside diameter preferably of 25 to-30 mils, and a wall thickness of approximately 3 to 5 mils. The outside diameter is preferably not over 35 mils. The tubing is filled with pure mercury and with the desired quantity determined by the length of the tube. The two ends 2 5 and 26 of the nickel tubing, are welded shut which produces a flat portion at the end, and the tube is then formed into a circle on a suitable mandrel and the ends welded together, as disclosed in Fig. 2.

This welding operation can be done either as a separate operation, or at the time the ring'is welded to the support wire or conductor 2|. The small diameter tubing utilized in the preferred dimensions provide a simple operation in making a completely tight weld across the flattened end. Because of the thin Wall of the tube and the fact that it is formed into a ring, it is very simple to heat the container 2t by means of the high freouency coil 23 to burst the tube in the finished device.

- The tube in the assembly has been completely filled with mercury by means of a vacuum and accordingly there is no danger of contamination of the discharge device because there is no air or a minimum of air included in the mercury. The mercury being extended throughout the ring with a very tiny mass per unit of length prevents the formation of any large globule of mercury flying against the glass wall of the container and breaking it upon the rupture of the tiny ring 26.

The preferred dimensions provide for approximately mg. of mercury in each inch of length of the tubing, and accordingly the mercury dosage for the device can be very accurately de termined by the length of the sealed off tube.

In case a larger amount of mercury is desired, I preferably utilize a longer length of tubing, but in this case form the major. part into a helical coil 21 illustrated in Fig. 5 and then weld the two ends together at 23.

In some cases, it may be desired to include both mercury and a gaseous medium in the device. For this purpose I provide a small glass tubing or container 30 illustrated in Fig. 6, and include in this container the gaseous medium in the interior 3| together with the measured amount of mercury 32 and a metal shot or slug 33. At one end of the container I preferably heat up a small area and blow it into the container to form a very thin re-entrant window 3 3. This container 30 may be attached to any convenient portion of the interior structure of the assembled lamp or electronic device such as the'press ll. When the device is jarred, the shot or slug 3i) will be driven against the thin window 34 and break it to release the gaseous medium 3! and the mercury 32 into the tube.

In Fig. '7 I have illustrated a further modification of Fig, 6 in which the gaseous medium has been enclosed in the container wall 35 together with the mercury 36. Also in this container is a high expansion wire 31 anchored into the wall and then extended in a straight wire 38 substantially to the opposite wall and then coiled back on itself in a spring 39, reaching back to the anchor place 40 of the wire. The coil will be heated by the high frequency device illustrated at 23 in Fig. 1 and will expand enough to break the wall 35 of the container and then release the mercury and gaseous medium into the device.

Fig. 8 is a still further modification in which the powerful hairpin spring 41 is so shaped that in the open position the points are wider than the largest diameter of the enclosing glass bulb 42. Before inserting into this bulb, the points are put under compression and held by a fusible length or loop of fusible wire 43. When the length is heated by high frequency it melts and releases the spring which breaks the bulb and, in turn, releases the mercury 44 and other desired gaseous medium included in the bulb 42.

Fig. 9 is a still further modification in which a coil spring 45 is put under compression and held by a fusible Wire 46 in a shell 41. When the length 46 is melted by high frequency, the spring 45 will be released and fly out of the shell with sufiicient force to break the glass bulb container 48.

In Figure 10 I have illustrated merely the glass bulb 49 with a metal shot 50 and the mercury therein, together with any gaseous medium desired. The device may be shaken vigorously so that the shot breaks the bulb and releases the mercury. This particular form. of the invention is, of course, not adapted with discharge devices having a delicate structure.

In Fig. 11 I have disclosed a hairpin bimetal 52 inside the bulb 53. An application of heat or high frequency thereto will force it to break the glass bulb and release the mercury 54 and other gaseous medium inside the bulb.

In Fig. 12 I have illustrated a similar hairpin bimetal 55 but I have also provided a thin interior' goose neck extension 56 of the wall which may be easily broken by the expansion of the bimetal hairpin for the release of the mercury 51.

In Figs. 6 through 12 I have mentioned the combination of mercury and other gaseous medium inside the containers. This other gaseous medium may be any one or combination of noble gases, such as argon, neon, etc. In case only mercury vapor is desired inside the tube, then, of course, only mercury would be inserted in the containers illustrated in Figs. 6 through 12.

Although I have described certain preferred embodiments of my invention, it is apparent that still further modifications may be made therein, and accordingly, I desire only such limitations to be imposed on my invention as are necessitated by the spirit and scope of the following claims.

I claim:

1. A casing for the introduction of mercury into a discharge device comprising an elongated member having an interior longitudinal chamber and having means closing said chamber at spaced parts thereof, said spaced closing means being secured externally with respect to each other.

2. A casing for the introduction of mercury into a discharge device comprising an elongated member having an interior longitudinal chamber and having means closing said chamber at spaced parts thereof, said spaced closing means being juxtaposed one on another and rigidly secured together.

3. A casing for the introduction of mercury into a discharge device comprising an elongated member having an outside diameter of from 15 to 35 mils and a wall thickness of 3 to 6 mils, the ends of said casing being closed and secured to each other.

4. A casing for the introduction of mercury into a discharge device comprising a tubular casing having flattened ends, said casing being bent into a loop with said flattened ends thereby brought together and secured to each other.

5. A casing for the introduction of mercury into a discharge device comprising a tubular casing having flattened portions next opposite ends of said casing, said flattened portions of opposite ends being secured together.

6. A casing for the introduction of mercury into a discharge device comprising a tubular casing having a wall thickness of 3 to 6 mils and having flattened ends, said casing being looped with the ends thereof juxtaposed and secured to each other.

7. An evacuated discharged device having electrodes therein, a tubular container having its ends secured to each other, mercury within'said container, said container being supported from one of said electrodes.

EDMUND A. REUTER.

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