US3859554A

US3859554A - Electric lamp with integral plastic base member

Info

Publication number: US3859554A
Application number: US728471A
Authority: US
Inventors: Luigi M Preziosi; Bernard R Fallon
Original assignee: Westinghouse Electric Corp
Current assignee: Philips North America LLC
Priority date: 1968-05-13
Filing date: 1968-05-13
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07
Also published as: FR2008429A1; GB1209282A; DE1923665A1; NL6907325A; JPS4926669B1

Abstract

An electric lamp having a vitreous envelope with a sealed end portion is permanently and securely fastened to a hollow preformed plastic base member by providing a laterally extending shoulder near the end of the envelope seal and embedding only that portion of the seal that extends up to and includes the shoulder in the base member itself, or in a body of cement that is located at the bottom of the base cavity. The partial embedment of the sealed end of the envelope in the base member itself is achieved by introducing vibrations of sufficient intensity into a selected portion of the base member to soften the plastic and then forcing the sealed end of the envelope into the softened plastic so that the latter flows around and behind the seal shoulder.

Description

United States Patent 1191 1111 3,859,554 Preziosi et al. 1 Jan. 7, 1975 1 ELECTRIC LAMP WITH INTEGRAL 3,253,249 5/1966 Hess CI 61. 339/144 x PLASTIC BASE MEMBER 3,265,923 8/1966 Preziosi et al. 313/318 3,447,016 5/1969 Rycroft 313/317 [75] Inventors: Luigi M. Preziosi, Llvingston;

Bernard Fallon Clark both of Primary Examiner-John W. Huckert Ni Assistant Examiner-William D. Larkins [73] Assignee: Westinghouse Electric Corporation, Attorney, Agent, straw)" Pittsburgh, Pa. [22] Filed: May 13, 1968 [57] ABSTRAFT An electric lamp havlng a v1treous envelope wlth a Allin-91917289471 sealed end portion is permanently and securely fastened to a hollow preformed plastic base member by 52 US. Cl 313/315, 313/318, 313/324, Providing a latehahy extending ShOhlder hear the end 313/312, 339/145 R of the envelope seal and embedding only that portion [51] 161.01 H0lk 1/46, 11011 1/44 of the Seal that extends up and includes the Shoul- [58] n of Search U 313/217 271, 244 315 der in the base member itself, or in a body of cement 313 31 317 3 4 34 35 32 339 34 that 18 located at Illfi bottom 0f the base cavity. The 355 312 324; 339/144 R 144 T 145 R, partial embedment of the sealed end of the envelope 145 T in the base member itself is achieved by introducing vibrations of sufficient intensity into a selected portion [56] Reierences Cited tof the bgse m?IT(l1bfdt0fS0tl;l6n thel plastic aTId thin orcmg t e seae en 0 t e enve ope mto t e so t- UNITED STATES PATENTS ened plastic so that the latter flows around and behind 2,892,992 6/1959 Grovemiller et al 313/318 X the h ]d 3,017,599 1/1962 Loesch 339/144 X 3,077,022 2/1963 Cullis 313/318 19 Claims, 15 Drawing gu ELECTRIC LAMP WITH INTEGRAL PLASTIC BASE MEMBER CROSS-REFERENCE TO RELATED APPLICATION The present invention provides an integral lamp-andbase assembly that is similar in some respects to the integral lamp and in situ-foamed plastic base assembly disclosed and claimed in copending application Ser. No. 554,493 of Vernon L. Plagge, which was filed June 1, 1966, is assigned to the assignee of this application and has now matured into US. Pat. No. 3,413,511.

PRIOR ART AND BACKGROUND OF THE INVENTION This invention relates to electric lamps and has particular reference to an electric incandescent lamp that has an integral plastic base member and is suitable for use with printed-circuit board components in automobiles and similar vehicles.

In order to reduce material and labor costs and facilitate lamp replacement, the automotive industry has designed and is presently using instrument panels that utilize a printed-circuit board having notched or keyed openings which receive specially designed lamp sockets. Such a socket is described in US. Pat. No. 2,825,038 issued Feb. 25, 1958 to R. C. Woofter. As is disclosed in this patent, the socket comprises a plastic body having contactors and means disposed to interlockingly receive and engage a conventional incandescent lamp' having a metal bayonet type base. The socket is provided with a flange and locking lugs that are arranged and adapted to clamp the socket in tightly seated engagement with the conductor portions of the circuit board when the assembled lamp-and-socket assembly is inserted into the circuit board and twisted or rotated a few degrees.

An improved socket of this type designed for printedcircuit board mounting is described'in U.S. Pat. No. 3,253,249 issued May 24, 1966 to L. J. Hess et all As is disclosed in this patent, the plastic socket contains a pair of U-shaped metal contactors that are adapted to interlockingly engage the notched portion of a socalled wedge-base" type miniature incandescent lamp. The lamp is terminated by a press seal that is formed on the end of the glass envelope and provided with transverse grooves or notches. The ends of lead wires are bent around the end of the press seal and into the notches and thus serve as the lamp contacts. Lamps of this type thus do not require a metal base and are referred to as baseless lamps.

While separable lamp-socket assemblies of the type described in the aforementioned patents permitted printed-circuit board components to be used in automotive instrument and lighting panels, the cost reduction was not as great as was expected insofar as a separate operation was required to insert the lamp into the socket and complete the assembly of the unit before it could be mounted on the circuit board. In addition, due to manufacturing tolerances some of the lamps would fit loosely within their sockets. When this occurred the lamp wobbled with respect to the socket during service operation and created a situation where a highresistance contact or even an open circuit could develop.

It has previously been proposed that a baseless buttsealed incandescent lamp be permanently fastened to a plastic socket of this general type (which thus serves as a base") by means of a ring or basing cement that joined the upper portion of the bulb neck to the inner peripheral or lip portion of the plastic base member, and then soldering the ends of the lead wires to two metal eyelets anchored in the bottom wall of the base. An integral lamp-base assembly of this type is disclosed in US. Pat. No. 2,892,992 issued June 30, 1959 to D. A. Grovemiller et al. Due to the smooth configuration of the bulb neck and the variations in the thickness of the bulb wall in this region, it was difficult to secure a firm bond between the lamp and base and, at the same time, avoid introducing strains in the glass that weakened the bulb. Moreover, the problems and cost associated with soldering the lead wires to the eyelets without melting or disfiguring the plastic base, coupled with the shock hazard produced by the exposed soldered connections at the end of the base, made this type of integral lamp-base assembly impractical.

It has also been proposed that a solid plastic base be molded directly onto the sealed end of a buttsealed incandescent lamp by placing the lamp in a mold and fill- .ing the mold cavity with a suitable hardenable insulating plastic such as epoxy resin. This concept is disclosed in U.S. Pat. No. 3,077,022 issued Feb. 12, 1963 to J. Cullis, Jr. However, the variations in the bulb diameters make it very difficult to prevent some of the plastic from flowing out of the cavity onto the bulb wall and producing unsightly ragged pieces of plastic or flashing which must be removed. This approach is thus also impractical from a cost and mass production standpoint, especially in view of the additional problems involved in molding a base of solid plastic onto the end of a bulb and carefullycontrolling the base configuration and dimensions.

OBJECTS AND SUMMARY OF THE INVENTION It is accordingly the general object of the present invention to provide an improved integral lamp-base assembly that can be quickly and securely mounted on a printed-circuit board and which can be readily and inexpensively manufactured on a mass production basis.

A more specific object is the provision of an integral lamp-and-base assembly that is rugged, devoid of shock hazards and utilizes a butt-seal or press-seal type lamp that is permanently fastened to a preformed plastic base member in accurate alignment therewith without inducing strains in or otherwise weakening the lamp envelope.

The aforesaid objects and other advantages are achieved in accordance with the present invention by providing a globular mass of solid fused glass on the outermost tip of the sealed end of the lamp envelope and embedding only this portion and an adjacent indented segment of the seal in the preformed plastic base member itself, or in a quantity of basing cement that is located at the bottom of the base cavity. The plastic (or cement) thus encapsulates the solid glass globule and extends around the laterally protruding shoulder of the globule and into the recessed or indented adjacent portion of the seal, which is also solid glass or has very thick walls due to the nature of the sealing operation. The lamp envelope is thus securely interlocked with the base member by embedding only the strongest part of the sealed end of the bulb in the plastic or cement.

The ends of the lamp leads are connected to portions of resilient metal contactors that are recessed within the confines of the plastic base member. The unit thus has a built-in safeguard against shock hazard.

In the case of a wedge-base lamp, a globule of fused glass is provided on the outer end of the press-seal and only this part and adjacent solid fused portion of the press-seal are embedded in the plastic base, or in the cement if the latter is used.

According to a preferred method of assembly, the partial embedment of the envelope seal in the plastic base is achieved by heating and softening the portion of the base located at the bottom of the base cavity by means of vibratory energy. The vibrations have a frequency greater than 1,000 cycles per second and are introduced into the plastic by a suitably designed transducer, or by vibrating the lamp envelope and placing it in contact with the base. In any event, the tip of the envelope seal is forced into the softened plastic until the latter flows over and behind the annular shoulder of the glass globule. The sealed-in lamps can thus be rapidly and securely fastened to the plastic bases without affecting the lamp quality or altering the exterior configuration or dimensions of the preformed bases.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the invention will be obtained by referring to the accompanying drawing, wherein:

FIG. 1 is an enlarged front elevational view, partly in section, of an integral miniature electric incandescent lamp-and-base assembly that is adapted for use with a printed-circuit board or the like; 4

FIGS. 2 and 3 are side elevational and bottom pla views, respectively, of the lamp assembly shown in FIG.

FIG. 4 is a fragmentary cross-sectional view of the assembly along the line IV-IV of FIG. 3;

FIG. 5 is a plan view of the plastic base component shown in the preceding figures;

FIGS. 6 and 7 are front and side elevational views, respectively, of the metal contactor members shown in FIGS. 14;

FIG. 8 is. an elevational view of an alternative lamp embodiment that includes a protective end cap, the base member and cap being shown in cross-section to illustrate their construction;

FIG. 9 is a partly exploded view of the capped lampbase assembly illustrating the manner in which the protruding portions of the lead-in conductors and contactor members are spot welded before the plastic end cap is joined to the base component;

FIG. 10 is a plan view of the end cap;

FIG. 11 is an exploded view of the sealed-in end of the lamp, the metal contactors, plastic base member, and end cap illustrating the manner in which they are assembled;

FIGS. 12 to 14 are fragmentary cross-sectional views of alternative lamp embodiments utilizing various types of contactor members and a partial filling of cement to join the lamp and base components together; and

FIG. 15 is a similar view of still another embodiment utilizing a wedge-base lamp having a globular tip portion that is embedded in the plastic base member.

DESCRIPTION OF EMBODIMENT I (FIGS. 1-7) In FIG. 1 there is shown an integral lamp-base assembly 15 which embodies the present invention and consists of a butt-sealed incandescent lamp l6 and a plastic base member 32 that are permanently joined together in operative relation by partly embedding the sealed end portion 17 of the lamp envelope 18 in the plastic base. The lamp 16 is of the miniature type (T3 /2 for example) and consists of a tubular glass envelope 18 that contains an incandescible filament 20 of coiled tungsten wire that is held in the desired configuration by a pair of wire supports 22 that are embedded in a glass bead 24 in the usual manner. The ends of the filament 20 are clamped in hooks formed on the ends of a pair of lead-in conductors 26 that are also embedded in and extend through the bead 24 and are hermetically sealed through opposite sides of the sealed end or butt scaled portion 17 of the envelope. The butt seal 17 is terminated by a thick-walled indented or tapered segment 28 and a globule 29 of solid fused glass thus providing a circumferential and laterally protruding shoulder 30 which merges with a circumferential recess 31 that is defined by the adjoining indented segment 28.

The plastic base member 32 is preformed and, as will be noted in FIGS. 1-3, is terminated at one end by a rectangular shaped boss 34 that serves as a flat knoblike extension for gripping the assembly and mounting it on the circuit board, and is terminated at its opposite end by a cylindrical collar 38 that encircles the bulbous part of the envelope 18. The collar 38 is provided with two integral lugs 40 that are diametrically opposite each other and are shaped to engage and effect a camlocking action with a printed-circuit board 52 (FIG. I) when the lamp assembly 15 is inserted into the keyed aperture 53 of the board and is twisted 0r rotated a few degrees. The base 32 is also provided with a laterally projecting flange 42 that is located at the juncture of and merges with the rectangular boss 34 and cylindrical collar 38.

The base member 32 has a central generally cylindrical cavity 33 and a pair of narrow channels 35 that communicate with the cavity 33 and extend into the boss 34 at opposite sides of the cavity, as is shown in FIGS. 1 and 5. The end face of the boss 34 is provided with a rectangular slot 36 (see FIGS. l-3) which extends completely across the length of the boss and is accessible to the channels 35 through openings 37 in the boss located at the bottom of the slot.

Exposed depressible contacts for the lamp 16 are provided by anchoring a pair of elongated metal contactors 44 (FIG. 1) of suitable resilient sheet metal, such as hardened brass, in the respective channels 35. As shown in FIGS. 1-3, the contactor members 44 each have an arcuate arm segment 49 that is terminated by a rounded end segment 50 and projects upwardly and laterally beyond the flange 42 through a pair of diametrically opposite slots 39 in the collar 38 and a pair of aligned recesses 43 provided in the face of the flange. The opposite ends 48 of the contactors 44 extend through the openings 37 into the slot 36 at the end of the boss 34 along with the outer ends of the lead-in conductors 26 where they are electrically joined together, either by spot welding or soldering. The joined ends of the leads and contactors are, however, completely recessed within the slot 36, as will be noted in FIGS. 1-3, and cannot be accidentally touched when the assembly 15 is gripped by the boss 34 and being mounted on the circuit board.

As will be noted in FIG. I, when the lamp-base assembly 15 is locked in place on the printed-circuit board 52 the arcuate laterally-extending portions 49 of the metal contactors 44 are depressed into the recesses 43 in the flange 42, with the result that the rounded tips 50 of the contactors are seated in pressure electrical engagement with the conductive elements 54 of the circuit board. When the contactors 44 are in relaxed condition, however (as shown in FIG. 2), the tips 50 and arcuate arm segments 49 are located a considerable distance above the recesses 43 in the flange 42.

As will be seen in FIGS. 2 and 3, the contactors 44, rectangular boss 34, the slot 36 in tne end of the boss, the reccesses 43 in the flange 42, and the slots 39 in the collar 38 are all disposed in a common diametrical plane that bisects the circular flange portion 42 of the base 32. Also, as shown in FIGS. 1 and 4, only globule 29 and adjacent indented segment 28 of the butt seal 17 are embedded in the boss and the plastic extends over and around the circumferential shoulder 30 into the annular recess 31. Hence, the lamp l6 and base member 32 are securely and permanently fastened together by a mechanical interlocking type of juncture with the thickest and strongest part of the butt seal.

The metal contactors44 are anchored in place within the respective channels 35 in the boss 34 by laterally projecting tongues 46 (FIG. 1) that engage and bite into the adjacent wall of the boss. This feature and the construction of the contactors are shown in greater detail in FlGS. 6 and 7. As there shown, each of the contactors 44 consist of an enlarged rectangular body portion 45 from which a triangular shaped tongue 46 is struck. The tongue is bent in the same direction as the arcuate arm portion 49, and the latter is terminated by the rounded end segment 50. The opposite end of the contactor 44 is terminated by a shorter and smaller rectangular segment 48 which is slightly smaller than the slit opening 37 provided in the end wall of the boss 34. As will be noted in FIG. 5, the slit openings 37 are not as wide as the channels 35 and the channels extend upwardly into the cylindrical collar 38 to serve as guides during the insertion of the contactor members 44. The central portion of the boss 34 is also provided with tapered arcuate passageways or grooves 41 that merge with the channels 35 and slits 37 to function as guides for the lead-in wires during the assembly operation. A centrally disposed circular recess 47 is preferably provided in the inner face of the boss 34 at the bottom of the base cavity 33 to reduce the amount of plastic which must be heated and displaced during the embedment of the tip of the butt seal 17, which will now be described.

METHOD OF ASSEMBLY While the partial embedment of the butt seal 17 in the boss portion 34 of the plastic base 32 can be achieved in various ways, as for example, by locally heating the central portion of the boss with sharply defined fires aimed at the circular recess 47 and then immediately forcing the globule 29 into the softened plastic, the preferred method is to soften the aforesaid part of the boss with vibratory energy. In accordance with this aspect of the invention, vibrations of a frequency and amplitude sufficient to heat and soften the plastic are introduced into the central inwardly-disposed surface portion of the boss 34 around and beneath the recess 47 and the end of the butt seal 17 is forced into the softened plastic until the plastic flows over and behind the circumferential shoulder 30 and into the circumferential recess 31 and encapsulates the end of the seal as shown in FIG. 1. The application of vibratory energy is then stopped and the lamp l6 and base member 32 are held stationary until the softened plastic cools and rigidifies.

The vibratory energy may be introduced into the aforesaid selected portion of the boss 34 by placing the end of the butt seal 17 in abutting relation with that part of the base 32 and vibrating the lamp 16 in a direction parallel to a static force that is simultaneously applied to the envelope 18. This can be accomplished with an apparatus of the type illustrated and described in US. Pat. No. 3,184,353 issued May 18, 1965 to L. Balamuth et al. However, in order to avoid possible damage to the filament 20 the vibratory energy is preferably introduced into the selected part of the boss 34 by placing the base 32 in a holder that is mounted on a suitably designed transducer which introduces the vibrations into the base and focuses them at the selected portion of the boss 34 in the region of the recess 47 to heat and soften only that portion of the base. Concurrently, the lamp 16 is placed in abutting relationship with the boss 34 and a static force of about 10 pounds is applied to the lamp, while the base 32 remains in a fixed position, until the desired degree of penetration of the butt seal 17 into the softened plastic is achieved. The vibrations should have a frequency of at least 1,000 cycles per second and a frequency of about 20,000 c.p.s. has given excellent results.

It has been found that softening of the plastic and the partial embedment of the butt seal 17 can be achieved in 1.2 seconds when vibrations of 20,000 cycles per second are used and the base member 32 is composed of asbestos-filled extrusion-grade polypropylene plastic that has a softening point of approximately 225F. Tests have indicated that satisfactory junctures using this method'can be achieved on a mass production basis in approximately 0.75 seconds and at even faster rates.

While polypropylene is preferred, any thermoplastic or other type of plastic having suitable flexibility and resilient characteristics, durability and chemical stability can be used. In the case of polypropylene it has been .found, that stabilizers had to be added to the resin to prevent it from chemically reacting with the brass contactors and eventually eroding them to the point when they disintegrated.

An additional advantage afforded by employing preformed plastic base members and integrally joining them to sealed-in electric lamps in accordance with the present invention is that the base and lamps can be readily color-coded for a quick visual check as to the lamp type and proper matching of the lamp and base components. This can be achieved by adding a suitable coloring additive of the glass from which the bead 24 is fabricated and an additive of the same color to the plastic from which the base 32 is fabricated so that they each have the same color. Thus, an T3% indicator lamp assembly designed for operation on 0.19 amps may have a black bead and a black base, whereas a lamp assembly of identical size but designed for operation on 0.27 amps may have a blue bead and a blue base.

Quality tests have shown that butt-sealed lamps joined to plastic bases by means of vibratory energy in accordance with this invention are securely locked in place even though only the globular tip and indented portions of the seal are embedded in the plastic. This has been demonstrated by the fact that when attempts were made to separate the lamp from its attached base the bulb would break at the indented portion 28 and the globular part 29 of the seal would remain embedded in the plastic.

EMBODIMENT II (FIGS. 8-11) In FIG. 8 there is shown a modified lamp-base assembly a that is similar to the unit previously described except that the boss portion 34a of the base 32a does not have a slot in its end face. The joined ends of the lead-in conductors 26a and end segments 48a of the elongated metal contactors 44a thus initially project beyond the end of the boss. According to this embodi ment, protection against shock hazard is achieved by fastening a plastic end cap 56 to the boss 34a after the lamp 16a has been joined to the base 32a and the spot welding operations have been completed.

As will be noted in FIG. 10, the end cap 56 has two

rectangular recesses

57 and 58 in its inner face which are aligned with the channels a in the boss 34a and which are of sufficient depth to accommodate and protectively enclose the protruding ends of the contactors and lead wires when the cap is fastened to the end of the boss (as shown in FIG. 8). The cap 56 is also provided with a central circular cavity 59 to accommodate any outward bulging of the end wall of the boss 34a which may occur should the globular tip 290 be larger than usual or the butt seal 17a inadvertently inserted too far into the boss 34a.

The end cap 56 is preferably formed from the same type of plastic as the base member 32a and, as shown in FIGS. 9 and 10, has a plurality of upstanding prongs 60 on its inner face. These prongs are softened by vibratory energy, after the overlying protruding ends of the contactors 44a and lead-in conductors 2611 have been spot welded by a pair of welding jaws 61 and 62 as shown in FIG. 10, and the base and cap pressed together, thus fusing the cap to the end of the boss and securely fastening it in place.

As shown in FIG. 11, the lead-in wires 26a of the sealed-in lamp 16a prior to assembly are spaced to lie in substantially the same planes as the channels 35a and inwardly of the contactor members 44a so that they will enter the tapered grooves 410 when the contactors are inserted into the channels 35a and the lamp is inserted axially into the base cavity 33a. Thus the various components are designed to interfit with one another when properly aligned and can be assembled automatically by a suitable machine.

EMBODIMENT III (FIG. 12)

In FIG. 12 there is shown another embodiment 15b therein the globular tip portion 29b and indented portion 28b of a butt-seal envelope 18b are embedded in and interlocked with a filling of rigidified basing cement 64 that is located at the bottom and only partly fills the base cavity 33b. The boss 34b is closed by an end wall 63 and the channels 35b terminate within the boss. The contactor members 44b are seated against the end wall 63 and are locked in pressured electrical engagement with the ends of the lead-in wires 26b by the tongues 46b that are compressed by the walls of the boss 34b which define the channels 35b.

The cement 64 is, of course, of a type that will form a strong bond with the plastic base member 32b and securely anchor the lamp 18b in place. A hardenable plastic resin such as epoxy is suitable.

EMBODIMENT IV (FIG. 13)

In FIG. 13 there is shown still another embodiment 150 that is similar to Embodiment [II but employs modified contactor members 44c. As will be noted, the portions 51 of the contactors 440 that are located within the plastic base member 320 are bent into U-shaped clamps that are compressively locked in sandwiched electrical engagement with the ends of the lead-in wires 260 by the walls of the boss 340 which define the channels 35c. The channels are so dimensioned that the U- shaped clamp portions 51, when the ends of the lead wires 260 are disposed in the clamps, will make a force fit with the boss 34c and be securely anchored in place when the contactors 440 are fully inserted into the channels 350.

As in the case of Embodiment III, the globule 29c and adjoining indented portion 28c of the butt seal 17c are embedded in a body of cement 646 that is located at the bottom of and only partly fills the base cavity 330.

EMBODIMENT V (FIG. 14)

The embodiment 15d shown in FIG. 14 is also similar to Embodiment III in that a partial filling of cement 64d is used to fasten the globular tip 29d and indented portion 28d of the butt seal 17d to the plastic base 32d. However, electrical connection with the ends of the lead wires 26d is achieved by means of rivet-like metal contactors 44d which have shank portions 65 that are force fitted, along with the lead wire ends, into suitably dimensioned cylindrical channels 35d that extend a short distance into the boss 34d from the lateral face of the flange 42d. The boss 34d extends across the full diameter of the flange 42d to accommodate the rivet-like contactors 44d and the recesses 43d extend from the respective channels 35a to the base cavity 33d to provide passageways for the ends of the lead wires 26d.

The heads 66 of the contactors 44d are seated against and protrude a predetermined distance above the face of the flange 42d and thus serve as the contacts for the lamp 16d when the assembly 15d is mounted on the circuit board.

EMBODIMENT VI (FIG. 15)

The invention is not limited to lamps of the buttsealed type but includes within its scope assemblies employing wedge-base lamps. Such an assembly 15a is shown in FIG. 15 and consists of a wedge-base lamp l6e having an envelope l8e that is terminated by a press seal l7e which is partly embedded in and permanently interlocked with the boss portion 34e of the plastic base member 32c.

The base member 32e is basically the same as the slotted-boss type base of Embodiment I except that the cavity 33e is not quite as deep. This permits the press seal l7e to be inserted into the boss 34e a distance such that the plastic not only encapsulates the globule 29a and indented portion 2812 located at the tip of the seal but extends into the transverse grooves 68 formed in the pressed faces of the seal. The plastic and boss 34e are thus' interlocked with the annular shoulder 30e of the globule 29c and also with the transverse shoulders 69 defined by the grooves 68.

As will be noted, the central portion 70 of the press seal l7e is thicker than and protrudes beyond the flat faces of the seal. Since it constitutes the tipped-off segment of the exhaust tube, this enlarged central portion is generally cylindrical and extends axially along the center of the seal He. The tapered segment 312 and globule 29c depend from this rib-like enlargement 70. The press seal l7e is, of course, solid glass throughout and is very strong.

Since the lead-in wires 26e extend axially from the end face of the press seal 172 rather than laterally through the envelope wall as in the case of a butt seal, suitable passageways (not shown) are provided in the boss 34e to permit the leads to extend laterally into the channels (not shown) and thence into the slot 36e along with the ends 48e of the contactors, to which they are spot welded.

Since the press seal 172 is of flattened configuration, an elongated recess (instead of a circular recess 47 as in Embodiment I) may also be provided in the inner surface of the boss 34a to minimize the amount of plastic which has to be heated, softened and displaced during the embedment of the end of the seal.

Of course, only the globule 29e and indented segment 28e at the end of the press seal We may be embedded in the boss 34e, as in the case of the butt-sealed lamp in Embodiment I. This would reduce the time required to assemble the lamp l6e and base 32e and provide a satisfactory junction. However, if this construction is used then care should be taken that a globule 29e with a sharply defined annular shoulder 30e is formed during the tipping off of the glass exhaust tube to provide a positive interlocking juncture with the plastic after embedment.

It will be appreciated from the foregoing that the objects of the invention have been achieved in that a novel integral lamp-and-base assembly has been provided which utilizes preformed plastic base components that are securely and tightly joined to butt-sealed or wedge-base type lamps without in any way damaging or impairing the quality of the lamps. A preferred method of rapidly joining the lamp and base components on a mass production basis using vibratory energy has also been disclosed.

While several embodiments have been illustrated and described, it will be understood that various modifications can be made without departing from the spirit and scope of the invention. For example, the lamp need not be of the incandescent type but can be a miniature glow lamp or contain other forms of energizable light sources. Also, the plastic base can comprise one which has the shape of a screw or bayonet type base and has suitable contacts anchored in its side or end walls, etc.

We claim as our invention:

1. An electric lamp comprising, in combination;

a vitreous envelope that contains an energizable source of light and has a sealed portion at one end that is terminated by a tip of solid fused vitreous material which has a laterally protruding shoulder that defines a transversely extending recess in the sealed end portion of said envelope,

a plastic base member having (a) a cavity that is larger than the sealed end portion of said envelope and (b) a pair of channels that are spaced from and communicate with said cavity, said envelope and base member being disposed in operative relationship with one another with the sealed end portion of the envelope extending into the base cavity, pair of lead-in conductors extending through the sealed end portion of said envelope and into the respective channels in said base member, and

contactor means anchored in the respective channels of said base member and electrically connected to the portions of said lead-in conductors that are disposed in said channels,

only the tip and adjacent recessed segment of the sealed end portion of said envelope being embedded in the interior part of the base member that defines the bottom of said cavity so that the resulting keyed interlocking juncture with the recess and shoulder of said envelope tip permanently joins the base member to said envelope, the remainder of the sealed end portion of said envelope being surrounded by but not embedded in said base member.

2. The electric lamp of claim 1 wherein the interior part of said base member in which said envelope tip and adjacent recessed segment are embedded comprises a body of cured cement that is located at the bottom of and only partly fills the base cavity and is bonded to said base member.

3. The electric lamp of claim 1 wherein said base member is composed entirely of plastic and said envelope tip and adjacent recessed segment are thus embedded directly in the bottom of said base member.

4. The electric lamp of claim 1 wherein;

said energizable light source comprises an incandescible filament that is connected to said lead-in conductors, the sealed end portion of said envelope comprises a butt seal that is terminated by an indented segment and a depending globular tip of solid fused vitreous material, and

the interior part of said base member encapsulates only the globular tip and the adjacent indented segment of the butt seal.

5. The electric lamp of claim 1 wherein;

said energizable light source comprises an incandescible filament that is connected to said lead-in conductors,

the sealed end portion of said envelope comprises a press seal of solid vitreous material that is terminated by an indented segment and a depending globular tip, and

the interior part of said base member encapsulates only the indented segment and globular tip of said press seal.

6. The electric lamp of claim 5 wherein;

said press seal has a transverse groove in one of its pressed faces, and

the interior part of said base member also encapsulates the portion of the press seal which defines said transverse groove, the remainder of said press seal being surrounded by but not embedded in said base member.

7. The electric lamp of claim 1 wherein;

said envelope is composed of glass and the sealed end portion thereof comprises a butt seal that is terminated by an indented segment and a depending globular tip of solid fused glass,

said base member is composed entirely of plastic and only said globular tip and an adjoining part of the indented segment of said butt seal are embedded in the bottom of said base member,

said base member (a) is terminated at its outermost end by an axially-extending boss and at its opposite end by a collar that extends around the portion of said envelope adjacent the butt seal, and (b) has a laterally extending flange that is located at the juncture of said boss and collar, and said pair of channels extended into said boss. 8. The electric incandescent lamp of claim 7 wherein; said collar is of generally cylindrical configuration and has a pair of integral resilient lugs in its outer surface that are diametrically opposite one another and adapted to engage and interlock in cam-like fashion with a keyed aperture in a printed circuit board or the like, and said contactor means comprises a pair of elongated metal members that are (a) anchored in the respective channels, (b) extend beyond the laterally extending face of said flange, and (c) serve as exposed contacts that are adapted to engage and connect with the conductor elements of said circuit board or similar component when the lamp is placed in interlocked relationship therewith. 9. The electric incandescent lamp of claim 7 wherein; said channels extend from the laterally disposed face of said flange into the side walls of said boss, and said contactor members comprise rivet-like elements the shank portions whereof are anchored in the respective channels in electrical engagement with the ends of the lead-in conductors and the enlarged head portions whereof are seated against and protrude beyond the laterally extending face of said flange. 10. The electric incandescent lamp of claim 7 wherein;

said channels are aligned and merge with slot openings in said collar and recesses in said flange, and

said contactor members comprise elongated sheet metal elements that are locked in the respective channels and have resilient arm portions that extend through and laterally beyond the slot openings in said collar and are aligned with but spaced from the recessed portions of said flange.

11. The electric incandescent lamp of claim 10 wherein each of said sheet metal contactor elements have a U-shaped portion that is located within the respective channels in sandwiched relationship with the end of the associated lead-in conductor and is compressively clamped in such position by the walls of the base member which define said channel.

12. The electric incandescent lamp of claim 10 wherein;

the boss portion of said base member comprises a flat knob-like extension that is disposed in a common diametric plane along with said contactor elements, channels, slot openings in said collar, and recesses in said flange,

said channels terminate within said knob-like extension, and

each of said sheet metal contactor elements are seated against the ends of the respective channels and locked in pressured electrical contact with the associated end portions of the lead-in conductors by a resilient tongue that protrudes from the contactor element and engages the adjacent wall of said extension.

13. The electric incandescent lamp of claim 12 wherein;

the end face of said knob-like extension has a pair of apertures therein that are of smaller dimension than and communicate with said channels.

each of said contactor elements has (a) an enlarged rectangular body portion that is seated against the bottom of the respective channels and has a deformed portion that defines said protruding locking tongue and (b) an end segment of smaller dimension than said body portion that extends through the associated aperture and beyond the end of said extension,

the end portions of the lead-in conductors also extend through said apertures and are electrically joined to the protruding end segments of said contactors,

a plastic cap is joined to and covers the end of said extension, and

said cap has a pair of spaced recesses in its inwardly disposed surface that are aligned with and protectively enclose the protruding joined ends of said lead-in conductors and contactor elements.

14. The electric incandescent lamp of claim 12 wherein;

the end face of said knob-like extension has a pair of apertures therein that are of smaller dimension than and communicate with said channels,

the end segments of said contactor elements and associated lead-in conductors protrude through said apertures and the exposed portions thereof are electrically joined together.

said extension has a slot that extends across the end face thereof along said diametrical plane, and

said apertures and the protruding end segments of the respective metal contactor elements and leadin conductors are recessed within said slot. and

the portions of the respective contactor elements and lead-in conductors that are electrically joined together are recessed within said slot.

15. A rear loading panel lamp comprising:

first and second electrical terminal means;

a lamp including an envelope and first and second leads extending from said envelope; and

a base member including:

(a) a wall defining a chamber in which a portion of said envelope is secured;

(b) first and second retaining means with which said first and second electrical terminal means, respectively, are slidingly engaged, said first and second leads being engaged between said first and second electrical terminal means and retaining means, respectively; and

(c) locking means operative in cooperation with said electrical terminal means to secure said lamp assembly to a circuit board.

16. A lamp according to claim 15 wherein said locking means include means for engaging said circuit board to restrain said lamp assembly in predetermined position in which said first and second electrical terminal means are in contact with first and second conductors on said circuit board.

17. A lamp according to claim 15 wherein said retaining means of said base member are exterior to said chamber of said base member. and said first and second leads of said lamp envelope extends from said chamber and are frictionally engaged between said first and second electrical terminal means and one surface of said first and second retaining means, respectively.

l3 l4 18. A base for a rear-loading panel lamp comprising: locking means operative to secure said base to a cira wall defining a chamber for receiving a portion of Quit board a lamp envelope;

a plurality of retaining means external to said membar, each being Operative to Secure an electrical 5 includes a lower external portion which lS laterally terminal which is slidingly engageable with said reelongated taining means; and

19. A base acccording to claim 18 wherein said wall

Claims

1. An electric lamp comprising, in combination; a vitreous envelope that contains an energizable source of light and haS a sealed portion at one end that is terminated by a tip of solid fused vitreous material which has a laterally protruding shoulder that defines a transversely extending recess in the sealed end portion of said envelope, a plastic base member having (a) a cavity that is larger than the sealed end portion of said envelope and (b) a pair of channels that are spaced from and communicate with said cavity, said envelope and base member being disposed in operative relationship with one another with the sealed end portion of the envelope extending into the base cavity, a pair of lead-in conductors extending through the sealed end portion of said envelope and into the respective channels in said base member, and contactor means anchored in the respective channels of said base member and electrically connected to the portions of said leadin conductors that are disposed in said channels, only the tip and adjacent recessed segment of the sealed end portion of said envelope being embedded in the interior part of the base member that defines the bottom of said cavity so that the resulting keyed interlocking juncture with the recess and shoulder of said envelope tip permanently joins the base member to said envelope, the remainder of the sealed end portion of said envelope being surrounded by but not embedded in said base member.

4. The electric lamp of claim 1 wherein; said energizable light source comprises an incandescible filament that is connected to said lead-in conductors, the sealed end portion of said envelope comprises a butt seal that is terminated by an indented segment and a depending globular tip of solid fused vitreous material, and the interior part of said base member encapsulates only the globular tip and the adjacent indented segment of the butt seal.

5. The electric lamp of claim 1 wherein; said energizable light source comprises an incandescible filament that is connected to said lead-in conductors, the sealed end portion of said envelope comprises a press seal of solid vitreous material that is terminated by an indented segment and a depending globular tip, and the interior part of said base member encapsulates only the indented segment and globular tip of said press seal.

6. The electric lamp of claim 5 wherein; said press seal has a transverse groove in one of its pressed faces, and the interior part of said base member also encapsulates the portion of the press seal which defines said transverse groove, the remainder of said press seal being surrounded by but not embedded in said base member.

7. The electric lamp of claim 1 wherein; said energizable light source comprises an incandescible filament that is connected to said lead-in conductors, said envelope is composed of glass and the sealed end portion thereof comprises a butt seal that is terminated by an indented segment and a depending globular tip of solid fused glass, said base member is composed entirely of plastic and only said globular tip and an adjoining part of the indented segment of said butt seal are embedded in the bottom of said base member, said base member (a) is terminated at its outermost end by an axially-extending boss and at its opposite end by a collar that extends around the portion of said envelope adjacent the butt seal, and (b) has a laterally extending flange that is located at the juncture of said boss and collar, and said pair of channels extended into said boss.

8. The electRic incandescent lamp of claim 7 wherein; said collar is of generally cylindrical configuration and has a pair of integral resilient lugs in its outer surface that are diametrically opposite one another and adapted to engage and interlock in cam-like fashion with a keyed aperture in a printed circuit board or the like, and said contactor means comprises a pair of elongated metal members that are (a) anchored in the respective channels, (b) extend beyond the laterally extending face of said flange, and (c) serve as exposed contacts that are adapted to engage and connect with the conductor elements of said circuit board or similar component when the lamp is placed in interlocked relationship therewith.

9. The electric incandescent lamp of claim 7 wherein; said channels extend from the laterally disposed face of said flange into the side walls of said boss, and said contactor members comprise rivet-like elements the shank portions whereof are anchored in the respective channels in electrical engagement with the ends of the lead-in conductors and the enlarged head portions whereof are seated against and protrude beyond the laterally extending face of said flange.

10. The electric incandescent lamp of claim 7 wherein; said channels are aligned and merge with slot openings in said collar and recesses in said flange, and said contactor members comprise elongated sheet metal elements that are locked in the respective channels and have resilient arm portions that extend through and laterally beyond the slot openings in said collar and are aligned with but spaced from the recessed portions of said flange.

12. The electric incandescent lamp of claim 10 wherein; the boss portion of said base member comprises a flat knob-like extension that is disposed in a common diametric plane along with said contactor elements, channels, slot openings in said collar, and recesses in said flange, said channels terminate within said knob-like extension, and each of said sheet metal contactor elements are seated against the ends of the respective channels and locked in pressured electrical contact with the associated end portions of the lead-in conductors by a resilient tongue that protrudes from the contactor element and engages the adjacent wall of said extension.

13. The electric incandescent lamp of claim 12 wherein; the end face of said knob-like extension has a pair of apertures therein that are of smaller dimension than and communicate with said channels, each of said contactor elements has (a) an enlarged rectangular body portion that is seated against the bottom of the respective channels and has a deformed portion that defines said protruding locking tongue and (b) an end segment of smaller dimension than said body portion that extends through the associated aperture and beyond the end of said extension, the end portions of the lead-in conductors also extend through said apertures and are electrically joined to the protruding end segments of said contactors, a plastic cap is joined to and covers the end of said extension, and said cap has a pair of spaced recesses in its inwardly disposed surface that are aligned with and protectively enclose the protruding joined ends of said lead-in conductors and contactor elements.

14. The electric incandescent lamp of claim 12 wherein; the end face of said knob-like extension has a pair of apertures therein that are of smaller dimension than and communicate with said channels, the end segments of said contactor elements and associated lead-in conductors protrude through said apertures and the exposed portions thereof arE electrically joined together, said extension has a slot that extends across the end face thereof along said diametrical plane, and said apertures and the protruding end segments of the respective metal contactor elements and lead-in conductors are recessed within said slot, and the portions of the respective contactor elements and lead-in conductors that are electrically joined together are recessed within said slot.

15. A rear loading panel lamp comprising: first and second electrical terminal means; a lamp including an envelope and first and second leads extending from said envelope; and a base member including: (a) a wall defining a chamber in which a portion of said envelope is secured; (b) first and second retaining means with which said first and second electrical terminal means, respectively, are slidingly engaged, said first and second leads being engaged between said first and second electrical terminal means and retaining means, respectively; and (c) locking means operative in cooperation with said electrical terminal means to secure said lamp assembly to a circuit board.

17. A lamp according to claim 15 wherein said retaining means of said base member are exterior to said chamber of said base member, and said first and second leads of said lamp envelope extends from said chamber and are frictionally engaged between said first and second electrical terminal means and one surface of said first and second retaining means, respectively.

18. A base for a rear-loading panel lamp comprising: a wall defining a chamber for receiving a portion of a lamp envelope; a plurality of retaining means external to said member, each being operative to secure an electrical terminal which is slidingly engageable with said retaining means; and locking means operative to secure said base to a circuit board.

19. A base acccording to claim 18 wherein said wall includes a lower external portion which is laterally elongated.