US2477340A

US2477340A - Discharge device, base, and method

Info

Publication number: US2477340A
Application number: US592696A
Authority: US
Inventors: Makenny William
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1945-05-08
Filing date: 1945-05-08
Publication date: 1949-07-26
Anticipated expiration: 1966-07-26

Description

July 26, 1949-. W.'MAKENNY v DISCHARGE DEVICE, BASE, AND METHOD Filed May 8, 1945 WA///// M014 M A/ 4 R N Y Em i-MM M w w 7 4 W Y. 5 B Y W H Patented July 26, 1949 2,477,340 DISCHARGE DEVICE, BASE, AND METHOD William Makenny, Mountain View, N. J assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 8, 1945, Serial No. 592,696

9 Claims. 1

This invention relates to discharge devices, and more particularly to those having elongated envelopes with a base at each end.

The principal object of my invention, generally considered, is to provide an improved form of base for the ends of elongated discharge devices.

Another object of my invention is to provide a single-contact base for the end of a tubular discharge device, said base comprising a shell of insulating material suchas a phenolic condensation product, of which Bakelite is typical, having a relatively large, generally-cylindrical flange for receiving the endportion of the envelope of said device, and 2:. lug or extension with a tapered hole for guiding a lead from said device to a contact ferrule at the end of said lug.

A further object of my invention is to provide a base for a discharge device comprising an insulating shell having a lug, and an end contact member associated with said lug, and applied as by snapping over a bead on the end thereof or embedded in said end portion as a lining for a lead-receiving aperture.

A still further object of my invention is to provide a base for a discharge device, said base being formed of Bakelite or the like, with a metal contact ferrule at the endthereof, said Bakelite being stabilized in dimensions by after baking. so as to insure that the ferrule will stay securely aflixed.

Other objects and advantages of the invention will become apparent as the description proceeds.

Referring to the drawing:

Fig. l is a fragmentary elevational view of a discharge lamp embodying my invention.

Fig. 2 is an enlarged fragmentary elevational view of the end portion of the envelope of such a lamp with which a base, embodying my invention, is associated.

Fig. 3 is a fragmentary view, corresponding with Fig. 2, but further enlarged and showing a metal ferrule as it is being applied to the base lug.

Fig. 4 is a fragmentary sectional view of apparatus for molding the insulating or Bakelite portion of a base embodying my invention.

Fig. 5 is a view correspondin to Fig. 4, but showing a modification.

Fig. 6 is a fragmentary view, partly in eleva tion and partly in axial section, of a base such as shown in Fig. 2, but modified.

Referringto the drawing in detail, like parts being designated by. like. reference characters, and first considering the embodiment of my invention illustrated in Figs. 1 to 4, inclusive, there is shown a discharge device or lamp ll comprising an elongated envelope [2, having a flare tube it at each end from a press M of which project leads [5 and I6 carrying an electrode device IT.

The lamp of the present embodiment is one in which a functionally single lead member, which however may be in the form of a plurality of wires or strands in parallel, extends to each electrode, the discharge beinginiti-ated by voltage rather than-by thermionic emission. For that reason, the lead wires I5 and I6 come together to a single contact, preferably brass, ferrule It on the base l9. The base shell 2|] is here formed of insulating material, preferably "Bakelite, and has a generally cylindrical flange 2| which receives the reduced portion 22 at the connected end of the envelope I2, and with which it is connected by cement 23. The base shell 20 has a lug 24 projecting axially therefrom in a direction opposite to that of the flange 2|, that is, from the transverse wall portion 25, which with the flange 2! forms the bottom of a cup-shaped element. i

The lug 24 has an aperture or hole 26 extend-- ing axially and passing from the inner surface oi. the Wall 25 to the tip of the lug 24. The aper ture is desirably conical or tapering, that is, decreasing fromthe inner surface of the wall 25 to a relatively small aperture at the tip of the lug 29, as particularly illustrated in Fig. 2. This allows for convenient threadin of the lead wires 55 and it into the aperture 26, and said leads are guided by funnel-shaped inner portion 21 into the more acutely tapering outer portion 23 of the aperture, that is, that portion beyond the outer plane of the transverse base wall 25. The outer portions of the leads I5 and I6 extend into the central aperture 29 of the ferrule IB, and are secured thereto in any desired manner, as by brazing or soldering 3|.

In order to hold the metal ferrule It in place on the lug 24, said lug'is desirably formed with a groove 32 defining a knob 33 therebeyond, and the ferrule I8 is formed with a bead 34, as by forcing the metal inwardly around the periphery, as

illustrated in Figs. 2 and 3, the inner diameter of said bead being appropriate, as compared with the outer diameter of the knob33, after fully curing or after-baking to stabilize the dimensions thereof, so that when the ferrule is forced over the knob, fromthe position of Fig. 3 to that of Fig. 2, the bead stretches sufliciently so that it slips over the knob and snaps into place in the flared groove 32, as illustrated in Fig. 2, the peripheral edge portion 35 of the ferrule at the same time beingpressed over lug portion 36, inward- 7 Inches Outer diameter of theknob .258 to .260

Inner diameter of the bead .245 to .250

Inner diameter at the groove'in lug .245 to .24?

Diameter of lug at base a a .296 to. .298 Normal inner diameter of ferrule adjacent rim 292th, .294

It will, therefore, be seen thatthe stlf fih llg DI". the bead over the knob may amount to from .008 to .015 inch and the stretching of the periphery of the ferrule over the base portion of the, lug may amount to from .002 to .006 inch. All of these dimensions are on the assumption that the Bake lite shell is either fully cured in; the mold or after-baked, so as to cure to set it sumciently that no appreciable contraction occurs after as sembly with the ferrule.

In Fig. 4 are illustrated. parts of apparatus for molding the Bakelite shell. This apparatus comprises a lower mold portion 38, an upper mold portion or plunger 39 and an aperture-forming inset ll. For removing the formedshell a knockout pin 432 is provided, which during the moldi operation forms the extreme bottom portion of the mold From a consideration of this mold will be seen that the bottomportion- 3% is formed as a single piece, not counting the knock-out pin 42, the uncured selected plasti'cor Bakelite being placed therein and squeezed by the plunger parts 3 9 and, All to entirely fill the space between them and the mold bottom, as illustrated. After partial curing in the mold by suitable heating. the upper portionssl ands I rise, followed by'upward movement of the knock-out pin 42 to remove the formed shell l9 from. the mold, the material of said shell being sufficiently resilient at that time, so that the knob portion 33 is squeezed to pass through thebead portion 53' of the lower mold section 33, and then springs back to approximately the original size. After removal from the mold, the shells iii are fully cured bylafter-baking, the following time-temperature relationship; that is, holding at a curing temperature of 175 C. for hours, having been found suitable for "Bakelitef Instead of making the shell then press-fitting'the metal contact portion thereover. said contact portion or ferrule may be incorporated with the shell during the process of molding. Such an embodiment is illustrated in Fig. 5 in which the ferrule :8 is placed in the lower mold element 38*, generally like the portion 38. of the embodiment illustrated in Fig. 4. The uncured selected plastic or- Bakelite is placed in said ferrule and portions of the mold not occupied thereby, and squeezed by the plunger parts se and Al to entirely fill the space between them and the mold bo-tto i and supported ferrule is It will be seen that while the ferrule l8- is desirably like that of the preceding embodiment and provided with a bead 34 the lower mold portion 38 6s unprovided withan interfitting boss portion, sothat after the plastic has been pressed in thefmold and ferrule, and suff ciently cured, the formed base may be removed by raising the mold upp rportions 39 and H followed by upward movemento'f theknock-out pin 42 In of the base, and

i such as illustrated in, Fig. 4,

the case of this embodiment, the Bakelite or other plastic is desirably cured in the mold, so that there is no shrinkage thereafter with respect to the ferrule, although it may if desired, be removed to another container for finishing the curing operation, as in the first embodiment.

Referring now to the embodiment of my invention illustrated in Fig. 6, there,- is shown a shell I9 which may be formedlike the shell IQ of the first embodiment, except that a metal, preferably brass, ferrule [8 shaped with an outstanding inner flange 44, as well as the outer flange 45 on the body portion 4.6-. is placed in the bottom of a mold, prior to introduction of he Bakelite or other moldable material. When, the; plunger descends, the ferrule H3 is molded in place in the plastic material, as illustrated, thereby avoiding the necessity of press fitting an exterior ferrule, as in accordance with the first embodiment.

As a further embodiment a ferrule. such as designated by the reference character [8 in the. preceding embodiment,,may be formed without an inner flange, such as that there designated 44, and pressed in place in the formed shell, after the latter has been suflicientiy cured, rather than being embedded in the plastic material to form it while in the bottom of the lower mold element,

From the foregoinggit will be seen that I, have devised an improved form of base for discharge. devices, such as fluorescent and other lamps. It will be understood that although the diameter of the flange on they base which is secured to the adjacent end of the lamp envelope may be changed to agree with a change in the diameter of the envelope, the lugportion and associated ferrule may be constantfor all eischarse devices of this general type, thereby adapting such lamps for use with sockets of uniform character.

Although preferred embodiments of my invention have been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended I claim: I

l. A discharge device comprising an. elongated envelope and a base, said. base comprising a shell. of moldable insulating material with, a generally cylindrical flange receiving and. secured to an end portion of said envelope and a lue extendin axially therefrom in a direction opposite to. that of said flange, said lug having a hole receivin a l ad f om said device and formed with an, ex terior roove, and a metal con act ferrule formed with an interior bead, of appropriate diameter mpared to the grooved lug, and secured to said l by a pressed fit causing, said head to snap into the ve; said lead connecting with said ferrule. I

2. A discharge device comprising elongated envelope and a base, said base. comprisin a Bakelite shell with a, generally cylindrical flange receiving and secured to an end portion of said envelope and a lug extending axially therefrom in a direction opp ite to hat of said flange. said lug having a hole and formed with an exterior groove defining an end knob with a diameter of about .259",.a lead from said de- Vice disposed in said hole, rule formed with an interior beadwith an into rior diameter of about-.247", and secured to said lug by a pressed fit causing said. bead to snap ov r said knob and into the. lug groove, and means connecting said lead with said, ferrule.

3. A base for a discharge device comprising a shell of moldable insulating material with, a gem a metal contact fer a erally cylindrical flange to receive and be secured to an end portion of the envelope of said device, a lug extending axially therefrom in a direction opposite to that of said flange, said lug having a hole for receiving a lead from said device and formed with an exterior groove, and a metal contact ferrule formed with an interior bead, of appropriate diameter compared with the grooved lug, and secured to said lug by a press fit, causing,

said bead to snap into the lug groove, so that said ferrule provides a contact for connection with said lead.

4. A base for a discharge device comprising a Bakelite shell with a generally cylindrical flange adapted to receive and be secured to an end portion of the envelope of said device, a lu extending axially therefrom in a direction opposite to that of said flange, said lug having a hole for receiving a lead from said device and formed with an exterior groove defining an end knob having a diameter of about .259 inch, and a metal contact ferrule formed with an interior bead having an interior diameter of about .247 inch and secured to said lug by a press flt, causing said bead to snap over said knob and into said lug groove and be thus held in place for connection with said lead.

5. A base for a discharge device comprising a stabilized Bakelite shell with a generally cylindrical flange adapted to receiveand be secured to an end portion of the envelope of said device, a lug extending axially therefrom in a direction opposite to that of said flange, said lug having a hole for receiving a lead from said device and formed with a trunk having a diameter of about .297 inch and an exterior groove defining an end knob having a diameter of about .259 inch, and a metal contact ferrule formed with a rim having a normal inner diameter of .293 inch, and an interior bead having an interior diameter of about .247 inch and secured to said lug by a press fit, causing said rim to be pressed over said trunk and said bead to snap over said knob into said lug groove and be thus held in place for connection with said lead.

6. A base for a discharge device comprising an insulating shell with a generally cylindrical flange adapted to receive and be secured to an end portion of the envelope of said device and a lug extending axially therefrom in a direction opposite to that of said flange, said lug having an axial hole for receiving a lead, the outer portion of said lug having a metal ferrule lining said hole for connection with said lead.

7. A base for a discharge device comprising a shell of moldable insulating material with a generally cylindrical flange adapted to receive and be secured to an end portion of the envelope of said device, a lug extending axially therefrom in a direction opposite to that of said flange, Said lug having a central aperture flaring from its end in the same direction as said flange, for receiving a lead from said device, formed with a trunk having a diameter of about .297 inch and an exterior groove defining an end knob having a diameter of about .259 inch, and a metal contact ferrule formed with a rim having a normal inner diameter of .293 inch, and an interior bead having an interior diameter of about .247 inch and secured to said lug by a press fit, causing said rim to be pressed over said trunk and said bead to snap over said knob into said lug groove and be thus held in place for connection with said lead, the peripheral edge of said ferrule being flared outwardly to facilitate starting the fitting on said lug, and said shell having a correspondingly formed relief groove around the trunk of the lug, snugly receiving said flared edge portion when the ferrule is in place.

8. A discharge device comprising an elongated envelope and a base, said base comprising a shell of moldable insulating material with a generally cylindrical flange receiving and secured to an end portion of said envelope, a lug extending axially therefrom in a direction opposite to that of said flange, said lug having a central aperture flaring from its end toward said envelope, formed with a trunk having a diameter of about .297 inch and an exterior groove defining an end knob having a diameter of about .259 inch, a lead from said device loosely disposed in said aperture, a metal contact ferrule formed with a rim having a normal inner diameter of .293 inch, and an interior bead having an interior diameter of about .247 inch and secured to said lug by a press fit, causing said rim to be pressed over said trunk and said bead to snap over said knob into said lug groove and be thus held in place for connection with said lead, the peripheral edge of said ferrule being flared outwardly to facilitate starting the fitting on said lug, and said shell having a correspondingly formed relief groove around the trunk of the lug, snugly receiving said flared edge portion when the ferrule is in place, and means connecting said lead with said ferrule.

9. A discharge device comprising an elongated envelope and a base, said base comprising an insulating shell with a generally cylindrical flange receiving and secured to an end portion of said envelope and a lug extending axially therefrom in a direction opposite to that of said flange, said lug having an axial hole flaring from its end toward said envelope, a lead from said device loosely disposed in said hole, a metal contact ferrule lining the outer edge portion of said lug, and means connecting said lead with said ferrule.

WILLIAM MAKENNY.

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

UNITED STATES PATENTS Number Name Date 1,372,007 Liarsou 8a Columbani Mar. 22, 1921 1,568,768 Reid Jan. 5, 1926 1,643,977 Buckwalter Oct. 4, 1927 1,969,777 Burke Aug. 14, 1934 2,010,037 Schulman Aug. 6, 1935 2,047,043 Strickland July '7, 1936 2,097,139 Wamser Oct. 26, 1937 2,099,056 Ferngren Nov. 16, 1937 2,117,762 Douglas May 17, 1938 2,135,380 Benge Nov. 1, 1938 2,177,105 Gustin Oct. 24, 1939 2,273,960 Hopkin Feb. 24, 1942 2,277,326, Huss Mar. 24, 1942 3,725 Kredler Nov. 9, 1943