US1813577A - Vacuum device - Google Patents

Description

W. KINTNER VACUUM DEVICE July 7, 1931.

Filed June 21, 1928 INVENTOR W. KIN

TNER BY ATTORNEY Patented July 7, 1931 UNITED STATES PATENT OFFICE WATSON KIN TNER, OF BLOOMFIELD, NEW JERSEY, ASSIGNOB TO WESTINGHOUSE Mn COMPANY, A CORPORATION OF PENNSYLVANIA VACUUM DEVICE Application filed June 21,

This invention relates to the manufacture of incandescent electric lamps and relates more particularly to one of the component parts thereof and the method for producing the same.

In the manufacture of incandescent electric lamps, radio tubes or other electrical vacuum devices including a sealed envelope, it is the practice to employ an internal structure composed of a number of consolidated glass parts. For example, in an incandescent electric lamp the internal supporting structure, termed the stem, includes a reentrant tube, termed a flare tube, which is sealed to the neck of the bulb, the flare tube in turn being consolidated with an exhaust tube and an arbor. These several parts are consolidated b fusing portions thereof to constitute a glass mass and leading-in wires extend my thro igh the mass and are sealed therein.

This mass is then compressed between suitable jaws and the resultant formation is termed a press. The press must necessarily have sufficient material to effectively seal the leading-in wires and to provide an internal bulbous cavity when air is directed down the exhaust tube while the mass is still plastic to provide an orifice between the exhaust tube and the interior of the bulb. The said mass must also have suflicent strength to withstand strains and prevent cracking.

It is important in the manufacture of an electrical device of the character above described to economize wherever possible, both in the amount of labor expended and in the material employed, The development of high speed machines has tended to greatly reduce the labor factor and the present invention aims to provide an internal structure for an electrical vacuum device with the use of a minimum amount of material Without substantially changing the accepted standard structure.

In accomplisihng the above, the flare or reentrant tube which was usually made of relatively thick wall tubing, in order to supply suflicient material in the mass or press at the point of union between the several parts, is in accordance with the present invention made of relatively thin wall. The

1928. Selfial No. 287,280.

required mass of material is-supplied by the disposition of a sufiicient amount of material, preferably in the form of an annulus of glass, which is disposed within the end of the flare tube, which is subsequently heated for consolidation with the arbor and exhaust tube.

It is an object of the present invention, therefore, to provide a method of producing a lamp stem with a minimum amount of ma terial.

Another object of the invention is to provide av lamp stem of the reentrant tube type in which the reentrant tube is provided with a relatively thin wall and additional material is supplied at the point of consolidation with t e other component parts of the stem.

Other objects and advantages of the invention will be evident from the following description and the accompanying drawings, in which Figure 1 shows the usual type of lamp stem as heretofore employed, partly in section;

Figure 2 is a side view of a flare or reentra-nt tube having a relatively thin wall;

Figure 3 is a side view of an annulus for supplying material to the end of the flare tu Figure 4 is a side view, partly in section, showing the several component parts of a stem in position to be consolidated in accordance with the present invention; and

Figure 5 is a sectional view of a stem as employed for an electrical device such as a radio tube.

As shown in Figure 1 in the drawings, a lamp stem ordinarily includes an arbor 10, a flare or reentrant tube 11 and an exhaust tube 12, all of which are consolidated in a press 13. Lead wires 14 and 15 extend through and are sealed in the press. Communication between the exhaust tube and the interior of a bulb is provided through an aperture 16, which is formed in the press 13 while the material is in a plastic condition.

As illustrated in Figures 2 to 4, a flare tube 17 is provided with a relatively thin wall, and a collar or annulus 18 havin a wall sufliciently thick to make up the 'fference in the material between the required thick wallflare tube and the thin wall flare tube as provided.

A stem manufactured in accordance with the present invention may be assembled in the usual manner the flare tube 17 being properly positioned, the collar 18 is, however, disposed adjacent to the lower end of the flare tube which is disposed on a support rod 19. An arbor 20 may be positioned in an aperture 21 provided in the rod 19, leading-in wires being properly positioned with their ends in pockets 22 provided at opposite sides of the aperture 21. An exhaust tube 23 may be held by jaws 24 in pro er relation to the annulus 18 and to an en of the arbor 20. Jaws 25 may also be provided for holding the flare tube in position.

When the several parts are properly positioned, a fire 23 is directed to impinge upon the outer wall of the flare tube adjacent to the annulus 18, so that these parts may be heated and fused together so as to be consolidated in a common mass, the annulus or collar 18 supplying suflicient material about the point of union between the parts, after which jaws 26 and 27 are actuated to compress the plastic portion to more firmly unite the parts in the so-called press.

While the material at the point of union between the parts is still plastic, a jet of air is directed through exhaust tube 23 by means of a nozzle 29 and a cavity, similar to the cavity 28 (shown in Figure 1) is formed and an aperture similar to aperture 16 (as shown in Figure 1) is produced to' constitute an orifice at an end of the exhaust tube for exhausting purposes.

The various jaws for holding the parts, as well as the support member for holding spirit and scope of the invention asset forth in the ap nded claims.

What is claimed is:

1. The method of lproducing a stem for a. vacuum device whic consists in disposing a glass exhaust tube within a glass flare tube, positioning an annulus of glass withm the flare tube and around the exhaust tube and a plying heat to fuse said annulus and portions of said tubes into a common mass.

2. The method of producing a stem for a vacuum device which consists in disposing a glass exhaust tube within a glass flare tube, positioning an annulus of glass within the flare tube and around the exhaust tube and applying heat to fuse said annulus and portions of said tubes into a common mass, and in directing a jet of air through said exhaust tube while said mass is still plastic, to provide an orifice at one end of said exhaust tube.

In testimony whereof, I have hereunto subscribed my name this 20th day of June, 1928.

WATSON KINTNER.

the arbor and the lead wires, are indicated more or less diagrammatically in the present drawings. It is obvious, however, that any suitable type of stem making machine or stem head, as well known in the lamp or radio tube making art, may be employed.

In the case of a radio tube stem, as shown in Figure 5, the reentrant tube 30 and an exhaust tube 31 are employed but the arbor is omitted. In this case, support and lead wires 32 are embedded in the press and inasmuch as a relatively large number of support wires are necessary, it has been desirable to use relatively heavy wall tubing for the flare tube to produce a large mass at the press. Thus the present invention is of particular advantage in connection with stems for radio tubes, as well as for stems for other electrical vacuum devices.

By reason of the present invention, a considerable saving of material -is effected and the cost of production is materially reduced.

Although a preferred embodiment of the invention is shown and described herein, it is to be understood that modifications may be made therein without departing from the

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