US2776852A - Stem mount for electric incandescent lamp - Google Patents

Description

Jan. 8, 1957 c, MORGAN 2,776,852

STEM MOUNT FOR ELECTRIC INCANDESCENT LAMP Filed July 16, 1953 INVENTOR. 0. c. Maze/21v.

United States Patent O STEM MOUNT non mgc rnro INCANDESCENT Donald C. Morgan, Orange, N. J., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 16, 1953, Serial No. 368,317 3 Claims. c1. 287-20) tice in certain types of electric incandescent lamps to mount a heat shield in-the neck of the lamp bulb for the purpose of interrupting heat convection currents in the bulb and to prevent overheating of the basal portion of the bulb. Heat reflectors or shields have heretofore most generally been supported beyond the end of the 9 glass press of the stem, upon the electrodes or oherwise, as exemplified by my prior application Ser. No. 248,377, filed September 6, 1951, now Patent 2,664,513 issued on December 29, 1953, and more recently it has been proposed in Patent No. 2,624,019 of December 30; 1952, to transversely groove the press and slide a deflector or shield in the groove for support therein. Such a construction, however, has the serious drawback of establishing a transverse weakened area opposite the bottoms of the grooves at which the stem tends to break, especially since the grooves have to be made with sharp corners next to the bottoms thereof.

In its general aspect, the present invention contemplates the elimination of the disadvantages and defects of the prior art in provision of a reflecting shield and improved means for mounting the same.

More specifically, the invention proposes a structure which is readily manufactured and easily assembled.

An essential characteristic of the invention resides in an improved mounting arrangement for said shield and avoidance of a weakened line of cleavage in the press.

More in detail, an object of the invention is to utilize inherent resiliency of the metal of the shield to admit the shield to its ultimate position and to retain it thereat.

Other objects, advantages and beneficial results will appear, as the description proceeds, to persons skilled in the art to which it appertains, both by direct recitation thereof and by implication from the context.

Referring to the accompanying drawing in which like numerals of reference indicate similar parts throughout the several views:

Figure 1 is a lamp in elevation with my invention incorporated therein;

Figure 2 is a longitudinal central section of a neck portion of the lamp as on line II--II of Fig. 1;

Figure 3 is a cross-section on line IIIIII of Fig. 2;

Figure 4 is a perspective view of a portion of the lamp stem; and

Figure 5 is a perspective view of the shield.

In the specific embodiment of the invention illustrated in said drawing, the reference numeral 1%) designates a usual sealed glass envelope or bulb of an electric lamp having a neck portion 11 provided with a reentrant stem 12 sealed thereto at the basal end of the neck and stem. The inwardly directed end of the stem 12 is formed with a press 13 through which are sealed a pair of leadin wires 14 connected at their outer ends respectively to the shell 15 and center contact 16 of a base 17. The base is of conventional type and is cemented as usual to the basal end of the envelope 10. At their inner ends, the lead-in wires 14 are connected to the opposite ends of a filament 18 which is heated during operation of the lamp. in the particular type of lamp shown, a glass rod or arbor 19 extends inwardly of the bulb from said press 13 in. axial alignment with the stern, said arbor having a button 20 terminating the inner endthereof and the button having a plurality of support wires 21 projecting therefrom to separated locations on the filament for giving support thereto in addition to the end support afforded by the aforementioned lead-in wires 14. The assembly of stem, lead-in wires, arbor, filament and support wires is fabricated as an entity and generally referred to as the stem mount, and thereafter inserted in the bulb with the basal rims of the bulb and stem sealed together. Within the stem is an exhaust tubulation 22 which opens into the bulb below the press and protrudes at the basal endof the stem where it is tipped off after the interior of the bulb has been appropriately exhausted and refilled with desired gas. in general, the lamp structure so far described is in accordance with prior art manufacture.

The difierence of construction over the prior art is in the press 13. In carrying out my invention, the press 13 is provided with a plurality of spot retainers 23, in this instance illustrated as substantially semi-spherical indentations or pockets. I have shown two such pockets on one side of the press evenly spaced from the inner end thereof and a single pocket on the opposite side of the press with like spacing from the inner end of the press but between the locations of the said two pockets.

A shield 24 of sheet metal and having general configuration of a disc, preferably of slightly less diameter than the inside diameter of the neck 11 of the bulb 10, is mounted on the press between the end of the stem and said retainers 23 of the press. For this purpose, the shield 24 is provided with a radially disposed slot 25 extending inward from the periphery of the shield with appropriate width and length to permit the shield to span the press and be substantially coaxial with the stem and bulb. The inward part of the slot 25 is provided with upstanding flanges 26 at the marginal edges thereof. Inasmuch as the slot has a width as great as the full thickness of the press, there is ample material enabling the flanges to be integral portions of the shield and bent up from the same when punching the disc to form the slot. The metal employed, such as nickel or even aluminum, has adequate resiliency for maintaining said flanges in substantial parallelism but yet capable of being temporarily sprung apart at their longitudinal free edges for mounting purposes.

Said flanges 26 are provided with spot retainers 27 to cooperate with the retainers 23 of the press. According to the illustrated embodiment, said retainers 27 of the flanges are constituted as projections stamped from the metal forming the flanges and project into the space between the flanges in number and spacing to coincide with the spot retainers of the press. In its broad aspect, the invention contemplates bump-and-socket form of cooperating retainers, and while the arbitrarily selected embodiment provides the socket in the press and the bump on the flanges, a reversal of this arrangement may be employed by provision of a socket in the flanges, and a bump on the press. In any event, as the shield is slid onto the press, the flanges spring outward to accommodate the protrusion of the bump and when the sockets and bumps coincide with the shield in place, the flanges spring back to substantial parallelism and the shield is held centralized by the cooperating retainers and maintained perpendicular to the press by said flanges and retainers. The three point suspension by the retainers prevents Wobble in a direction across the-broad faces of the press and in addition keeps the shield from sliding laterally so that there will always be a gap between the entire periphery of the shield and the envelope. Furthermore, it is important to note that the character of retainers provided as an inherent part of the press avoids sharp edges by being rounded and introduces no line of cleavage or other weakening of the press.

I claim:

1. A stein mount comprising a glass stem having an end thereof flattened to form a press, a plurality of spot retainers constituted as integral parts of said press, a

shield having a radially disposed slot an inward portion whereof provides flanges separated in parallelism a distance corresponding to the thickness of the press and having inherent resiliency, said press and flanges having cooperating bump and socket type of spot retainers adapted to be brought to registration by flexing said flanges to accommodate the protrusion of the bumb retainers and to resiliently return the flanges inwardly upon registration of the said retainers.

2. A stem mount comprising a glass stern having an end thereof flattened to form a press providing opposite broad faces, a shield having a slot the width whereof is substantially equal to the thickness of said press between said faces, whereby the shield is slidable laterally onto said press, said press having curvilinear indentations constituting spot retainers, and said shield having resilient protrusions registering with and engaged in said indentations.

3. A stern mount comprising a glass stem having an end thereof flattened to form a press providing opposite broad faces, a shield having a slot the width whereof is substantially equal to the thickness of said pre'ssbetween said faces, whereby the shield is slidable laterally onto said press, said press having curvilinear indentations constituting spot retainers, said shield having resilient flanges parallel to and in engagement with said faces, and said flanges having protrusions next to the longitudinal edges thereof, said protrusions registering with and engaged in said indentations of the Press.

References Cited in the file of this patent UNITED STATES PATENTS 1,694,154 Westendorf Dec. 4, 1928 2,164,901 Chilo July 4, 1939 2,532,162 Goss Nov. 28, 1950 2,624,019 Leighton Dec. 30, 1952

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