US2133940A - Electric lamp - Google Patents

Description

H. D. WlL SON ELECTRIC LAMP Oct. 18, 1938.

Filed June 7, 1937 frwemam Patented Oct. 18, 1938 UNITED sures PATENT OFFICE 38,940 ELECTRIC LAMP Harold Douglas N. Heath, Roe eye Electric Companytion of Delaware Wilson, Gloucester, and Walter port, Masa, asslgnors to Birds- Dover-,Del.,acorpora- Application June 1, 1m, Serial No. 140,150

Claims. (cl. 176-82) sometimes permits separation of the bulb from the base.

The general objective of our invention is the provision of a mechanically attached base which will obviate the difllculties above discussed, and which may be achieved with very little departure from the present standard practice of basing incandescent lamps. In one aspect the invention consists in an anchor member or clip which may be secured in position upon the end of the bulb neck or adjacent thereto by connection with the lead wires, or other wires sealed into the bulb, and thus held in position upon the bulb, and be- 5 ing also shaped to make engagement with the metal base. Such an anchor member may be embedded in the cement employed in commercial basing operations without requiring any modiilcation of the operation. Although under conditions of excessive heat the cement may completely lose its adhesive properties, it does'not physically disintegrate, and so is still capable of serving as a filler or positioning. medium holding the anchor member firmly against displacemeat. I

The anchor member herein shown for illustrative purposes may be constructed advantageously from a thin metal stamping and a washer or disk of heat-resisting insulating material, the assembled member being provided with spaced passages for the lead wires, and in some cases with an aperture for the end of the exhaust tube which usually projects somewhat beyond the end of the bulb neck. The metal portion of the anchor 5 member is provided with inclined outwardly extending projections or prongs of a resilient character which are adapted positively to engage the threads of the base or other irregularities in its surface. Preferably and as herein shown, the metal portion of the anchor member is cut away so as to clear at least one of the lead wire passages, with the result that the lead wires are insulated from each other at this point and also positively spaced from'each other, By threading the anchor member over the end of the egshowing the base haust tube the parts'may be maintained in concentric relation and the lead wires prevented from being short-circuitcd even if the bulb should be twisted with respect to its base.

While our invention in its ultimate form is embodied in an incandescent lamp, in another aspect it comprises as a distinct article of manufacture, a novel anchor device comprising a united insulating disk and metal stamping having one wire passage in and another wire passage in the disk alone. As herein shown the disk and segment are united by metallic eyelets, which beside affording satisfactory fastening means. supply a metal body adjacent to the lead wires which facilitate the 15 application of solder thereto if that material is to be used in securing the anchor member to the bulb.

These and other features of the invention will be best understood and appreciated from the 0 following description of a preferred embodiment thereof, selected for purposes of illustration and shown in the accompanying drawing in which- Flg. l is a view in elevation, partly in section,

' in its assembled relation upon 25 the neck of the bulb.

Fig. 2 is a similar viewin perspective with the metal base omitted.

Fig. 3 is a sectional her, and

Pig. 4 is a view in parts tion.

The lamp partially shown in Figs. 1 and 2 comprises a bulb It of usual commercial construction as terminating in a neck ll of reduced diameter. Within the neck is disposed the usual mount l2 terminating at its inner end in a press in which are sealed the two lead wires it and H. At its outer end or flare the mount I! is sealed to the 40 end of the neck II, a circular bead ll including the line of seal. Within the hollow mount 12 is arranged the exhaust tube It, and this, after it is sealed on in the operation of exhausting the bulb, projectsoutwardly beyond the plane of the 45 bead Ii.

The lamp includes in its structure a metal base I! of conventional shape, having threads formed in its side walls and an insulated end terminal for one of the lead wires. The base so encloses the bead I! of the neck with substantial clearance and is held in position upon the neck II by cement is, as well as by the holding action view of the anchor memperspective of the component of the anchor member in separated relaof the anchor member, which will now be more particularly described.

the combined disk and stamping. l0 7 As herein shown the anchor member of the clip includes in its structure a fiat circular washer.

or perforated disk 20 of insulating material such as mica or hard fibre. In exterior diameter it preferably coincides substantially with the exterior diameter of'the bead l5 and its interior perforation is of sufiicient diameter to permit the passage of the exhaust tube IS with ample clearance as shown in Fig. 2. In one side of its body the disk 20 is provided with a tubular eyelet 2|, which forms one of the lead wire passages.

The metallic portion of the anchor member comprises a thin metal stamping 22 which is generally circular or segmental in shape, having a recess 23 therein preferably coinciding partially with the annular wall of the perforation in the disk 20 and of sufficient width to clear the eyelet 2i by a substantial margin. The stamping is provided also with inclined outwardly extending prongs or teeth 24 spaced about its periphery and diverging outwardly so as to clear the outer circumference of the disk 22. The prongs 24 are preferably somewhat resilient in character and are disposed with their outer ends in a circle of larger diameter than the base I! but so that they may yield and temporarily contract when the base is forced over them in the basing operation. The metal stamping 22 and'the insulating disk 20 areunited by the three eyelets 25, one or more of which may form lead wire passages through the anchor member at spaced points. Any one of the eyelets 25 may be used as a lead wire passage in combination with the passage of the eyelet 2| which, as already explained, is completely insulated from the three passages of the eyelets 25.

In the present commercial system of basing lamp bulbs a charge of thermoplastic cement is supplied to the base and then the base is applied to the neck of the bulb and held in position while the cement'is heated until a union is formed with the glass of the neck. In accordance with our invention no departure is required from this commercial procedure, although it'is supplemented by the step of assembling and fastening the anchor member in position. This may be done as suggested in Fig. 2 by threading the lead wires l3 and I4 through the passages of the eyelets 2| and 25 and positioning the anchor member concentrically upon the end surface of the'bead l5 with the end of the exhaust tube l6 passing through its central perforation. A drop of solder 26 is now applied to both lead wires just above the flange of the respective eyelets 2| and 25 and in this manner the anchor member is positively and permanently held in position fast upon the bead l5. The base I! is now provided with a. charge of cement in plastic condition and pressed upon the end of the neck ll. In this movement the corrugations or threads in the inner wall of the base are advanced beyond the endsof the outwardly extending prongs 24. The latter are first contracted by the relatively stiff cement in the base and then, as the cement is softened by heat, they spring .out resiliently from the neck and snap into one or another of the corrugations, becoming mechanically interlocked therewith so that it is impossible to retract or remove the base without stretching or breaking the lead wires. In this operation the plastic cement I8 is caused to flow about the clip so that the prongs thereof become embedded in cement as best shown in Fig. l. The cement hardens within a short time and acts effectively to prevent displacement of the clip and particularly to prevent any disturbance of the interlocking engagement between the prongs 24 and the surface irregularities provided by the corrugations in the walls of the base. The result is that the interlocking engagement of the parts cannot be disturbed so long as the cement acts as a filler. If the cement is heated to the point that it.loses'its adhesive properties, it is still effective indefinitely as a filler and positioning medium and the mechanical connection of the metal base and the glass neck is permanently maintained. 7

While we have shown lead wires soldered to or above the eyelets of the passages, any wires sealed in the bulb or mount would serve as well, and any form of mechanical connection may be substituted for solder within the scope of the invention. Also, it is not necessary that the anchor member be maintained in direct engagement with the end of the bulb neck and if desired any sort of spacing element may be interposed between the two.

Having disclosed our invention and described a preferred embodiment thereof for illustrative purposes and not by way of limitation, we claim as new and desire to secure by Letters Patent:

1. An electric lamp having a bulb with lead wires sealed in its neck portion, a base, and a clip having a fiat heat insulated body bearing upon the end of the neck and held in position thereon by mechanical connection with the lead wires and having base-engaging projections.

2. An electric lamp including in its structure a bulb having a circular head at the end of its neck, a fiat anchor piece held rigidly against the outer annular surface of the bead and having outwardly projecting prongs, and a metal base held upon theneck of the bulb by interlocking engagement with said prongs.

3. An electric lamp including in its structure a bulb having a hollow mount sealed within its neck and presenting a rounded annular head at the, end of the neck, lead wires passing out through the mount, a disk-shaped clip having spaced radial projections about its periphery and being located upon the bead and held in place by connection with the lead wires, and a metal base enclosing the clip and engaged by projections thereon. I

4. An electric lamp having a bulb with lead wires sealed therein, a clip comprising an insulating disk having a toothed metal segment fast thereto, a wire passage through the disk spaced from said metal segment, means for connecting a lead wire and said clip, and a base engaged by theteeth of said segment.

5. In an electric lamp, an anchor device comprising a united insulating disk and metal seg: ment, the device having a wire passage in the combined disk and segment and another wire passage in the disk alone.

6. In an electric lamp, an anchor device comprising an insulating disk having a wire passage, a metallic segment having radially projecting prongs, and an eyelet uniting said disk and segment and forming another wire passage in the device. I

7.In an electric lamp, a bulb having lead wires sealed therein and a metallic base upon its neck portion, and an anchor member comprising an insulating disk having a wire passage and a sheet metal piece coextensive with a portion of said disk and clearing said wire passage, the sheet metal piece being extended beyond the periphery of the disk to engage the base and one of the lead wires having means adjacent to said wire passage for holding the anchor member in contact with the neck of the bulb.

8. An electric lamp having a bulb with a ho]- low mount sealed into its neck and an exhaust tube and lead wires passing out of said mount, in combination with a metallic base and an anchor member encircling the exhaust tube, engaging the base and being held in position against the end 01 the bulb neck by connection with the lead wires.

9. An electric lamp having a bulb with a metallic base and an exhaust tube terminating within the base, and a periorated anchor memend oi the neck by

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