US3047829A

US3047829A - Electric lamp base

Info

Publication number: US3047829A
Application number: US853764A
Authority: US
Inventors: Robert W Mouat
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1959-11-18
Filing date: 1959-11-18
Publication date: 1962-07-31
Anticipated expiration: 1979-07-31

Description

July 31, 1962 R. w. MoUAT 3,047,829

ELECTRIC LAMP BASE Filed Nov. 18, 1959 ITWVETWTOT'I Rober t W. Moua t' Jo a /7%,

8 His A t to neg 3,ll47,82 Fatented July 31, 1962 3,047,829 ELEQTRHZ LAMP BAE Robert W. Mouat, Mentor-on-the-Lake, ()hio, assignor to General Electric Company, a corporation of New York Filed Nov. 18, N59, Ser. No. 853,764 1 (Ilaim. (Cl. 339-127) The present invention relates to lamp bases generally and more particularly to bases of incandescent electric lamps of the low voltage type commonly known as miniature lamps and used extensively for automotive vehicles.

In utilizing such lamps in automobiles, for example, the lamps are frequently incorporated in assemblies which include housings for the lamps. The lamp housing is sealed to exclude from the interior thereof dust, moisture and other contaminants, such as road salts, encountered under normal operating conditions of the vehicle. A type of miniature electric lamp in common use in such assemblies is provided with a two-contact or three-contact bayonet type base having a single eyelet contact or two eyelet contacts which base is mounted in a compatible socket secured to the lamp housing. The socket is usually exposed, at least in part, outside the housing. It is customary in the art also to seal ofl from the ambient the exterior of the socket supporting part of the housing to avoid the usual contaminants from entering the socket and the interior of the housing through the socket itself or through its connection with the housing.

The principal object of the present invention is to provide a lamp base for electric lamps useful in assemblies of the above type which base is engageable directly with the housing of the assembly and thus eliminates the need for the usual socket. Another object of the invention is to provide a lamp assembly including a lamp housing and a lamp having a base which seals an opening in the housing for receiving the based lamp and wherein the lamp is attachable to and detachable from the lamp housing by a simple manual push and twist motion.

A further object of the invention is to provide a base for a miniature electric lamp which accurately positions the light source in the lamp with respect to the mounting parts of the base and the lamp housing. A still further object of the invention is to provide a lamp base of the above type which is adaptable for insertion from the rear or the front of the lamp housing. Further objects and advantages of the invention will appear from the following detailed description of a species thereof and from the appended claim.

In accordance with these objects the lamp base of the present invention includes an elongated cylindrical hollow shell open at one end for receiving the neck of a lamp bulb and closed at the opposite end by a comparatively thick end wall into which hollow electrical metal contact pins are aflixed as by molding, a lamp centering collar integral with the shell for engaging the sides or inner peripheral edge of a lamp base receiving opening of a lamp housing, a plurality of outwardly extending holding ears integral with and spaced apart at approximately equal angular distances around the centering c'ollar in a common seating plane normal to the axis of the base shell and a dished, stiffly resilient annular flange integral with the collar and spaced in a longitudinal direction from the common seating plane of the ears. The concavity of the dished flange faces in the direction of the common plane of the ears so that its outer periphery is in closer proximity to that plane than its inner periphery. One of the cars has a locking key or boss integral therewith extending toward but terminating short of the inner periphery of the flange.

The flange is so located with respect to the common seating plane of the ears that when the base is inserted in a keyhole opening in a panel of a lamp housing the ears together with the locking key may be passed completely through and slightly beyond the opening and the base then manually rotated in the opening with the ears on one side of the panel and with the flange flexed and pressed against the opposite side of the panel.

On release of the base in its rotated position the flexed flange forces the ears against the-panel and moves the locking key into a locking slot provided in the panel while the outer periphery of the flange remains tightly pressed against the outer surface of the panel to seal the space around the panel opening and prevent the entrance of contaminants into the housing. The flange in this rotated locked position of the base is partially flexed and firmly clamps the base onto the panel. The base may be detached from the panel in the same manner.

The base, except for the contact pins, is of molded electrically insulating organic plastic material, such as thermoplastic nylon. The tubular metal contact pins extend longitudinally outward from the closed end of the base shell for engagement With terminals of an electric power source with their inner ends afllxed in the end wall of the shell and opening into the interior of the shell for receiving the usual current carrying inlead wires extending from the neck of the lamp bulb accommodated in the open end of the shell.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown in which:

FIG. 1 is a vertical sectional view of a lamp assembly including one type of lamp housing, by way of example, supporting an electric lamp having a base embodying the invention,

FIG. 2 is a perspective View on an enlarged scale of the lamp base shown in FIG. 1,

FIG. 3 is a top plan view of the base shown in FIG. 2,

FIG. 4 is a fragmentary View of the part of the lamp housing for supporting the based lamp shown in FIG. 1,

FIG. 5 is a bottom plan view of the base shown in FIGS. 1 to 3 with part of the flange broken away and FIG. 6 is an enlarged, fragmentary, partly sectional view along the lines 66 of 'FIG. 3 showing the relative position of the flange and the end of the locking key.

Referring to the drawing, the two-filament electric incandescent lamp mounted in the housing of the lamp as sembly illustrated in FIG. 1 includes a sealed light-transmitting glass envelope or bulb 1 of generally pear-shape provided with a neck 2. Two pairs of current carrying inlead wires 3 and 4, 5 and 6 extend from the envelope 1 which is provided with the usual exhaust tip 7. The inleads 3 and 4, 5 and 6 are sealed into a re-entrant stem of the bulb and each pair of inleads supports in the bulb 1 an incandescible filament to the opposite ends of which the inleads 3 and 4, 5 and 6 are electrically connected. Such lamps are useful as tail, stop and direction signal lamps for automotive vehicles, as is well known. Since the structure of lamps of this type is well known in the art and forms no part of the present invention, the internal structure of a lamp has been omitted from the drawing for simplicity of illustration.

The lamp also includes a base 8 embodying the invention and described below which is secured to the bulb 1 of the lamp by a ring 9 of conventional lamp basing cement which closes the space between the neck 2 of the lamp bulb 1 and the cylindrical wall of the barrel or shell 10 of the base at the open end of the shell 10 as shown in FIG. 1.

The based incandescent lamp is mounted in the lamp housing 11 of the lamp assembly. The housing 11, which is shown as an example, includes a light-transmitting generally globe-shaped colored cover or lens 12, an annular flat panel or cover plate 13 over the mouth or opening of the globe l2 and a retaining ring 14. The plate 13 has a central opening therein through which the bulb end of the lamp is inserted from the rear of the housing 11. The retaining ring 14 is bolted, as shown at 15, to the part 16 of a vehicle which part defines an opening into the interior of the vehicle. A gasket 17 is interposed between the cover plate 13 and the flange 18 of the globe 12 to seal the joint between these members of the housing 11. The plate 13 and the globe 12 of the housing 11 are held together and are removably secured to the vehicle by the retainer ring 14 bolted to the vehicle part 1-6.

The lamp base 8 embodying the invention is mounted in the central opening in the annular cover plate 13 and seals the lamp-receiving opening therein as described below so that the interior of the housing 11 is completely sealed by the gasket 17 and the base 8 against the entrance of contaminants of the kind mentioned above to keep the interior of the housing 11 and the parts of the lamp enclosed thereby clean for maximum illumination of the globe 12 by light emitted by the incandescent lamp.

Accordingly, the base 8 is provided with an integral flange 2t) of larger diameter than that of the lamp receiving opening in the plate 13. The flange 2t) is slightly dished and has resilient properties so that when the based lamp is properly mounted in the housing 11 as described below, the outer peripheral portion of the flange bears against the surface of the cover plate 13 around the opening to effectively seal the latter against entrance of contaminants.

The lamp receiving opening in the cover plate 13 is a keyhole type of opening having a circular part 21 (FIG. 4) slightly larger in diameter than the maximum diameter of the bulb 1 of the electric lamp for passage of the bulb therethrough and spaced

slots

22, 23 and 24 for the passage of holding lugs or

ears

25, 26 and 27, respectively, provided on the base 8 as described below. The plate 13 is also provided with a slot 28 for receiving a locking boss or key 29 on the car 25. The

slots

22, 23 and 24 and the respective matching

cars

25, 26 and 27 are of different lengths and widths to assure ease of insertion and positive rotary positioning of the base and therewith the lamp filaments in the housing 11. The lead portions of the

ears

25, 26 and 27 and the key 29 are chamfered to facilitate mounting the base on the plate 13.

The dished flange 20 and the

ears

25, 26 and 27 are integral with the collar 30 formed on the shell The collar 30 is concentric with the shell 10 of the base and has an outer diameter slightly larger than the maximum diameter of the bulb 1 and closely approaching the diameter of the circular part 21 of the keyhole opening to center the lamp base in the plate opening. The

ears

25, 26

and 27 extend radially outward from the collar 30 and are arranged at approximately equal angular distances around the collar and have seating surfaces for engaging the inner surface of the plate 13 when the electric lamp is mounted in the housing. The seating surfaces of the A three cars are disposed in a common plane normal to the longitudinal axis of the base and establish a seating plane for accurately positioning the lamp filaments in the housing 11 in a direction longitudinally of the base.

The concavity of the dished resilient flange faces the seating plane of the ears on the side of the plane away from the open end of the shell. The outer peripheral portion of the flange when the latter is not flexed, is within or closely adjacent the common plane of the seating surfaces of the ears. In any event, the outer peripheral portion of the flange should be spaced from the common seating plane of the ears a distance substantially less than the thickness of the support plate 13 in order to firmly clamp the plate between the ears and the flange to hold the lamp firmly on the housing.

The juncture between the flange 20 and the collar 10, that is, the inner periphery of the flange, and the end of the locking key 29 are spaced apart longitudinally of the base a distance slightly greater than the wall thickness of the plate 13 as shown in FIG. 6. Thus, when the base 8 is inserted in the keyhole opening in the plate 13 with the

ears

25, 26 and 27 in their

matching slots

22, 23 and 24, the base first may be thrust inward of the housing 11 against the force exerted by the flange 2th a sufficient distance for the key 29 to pass completely through and clear the slot 22. The base then may be rotated a sufiicient distance in the keyhole opening to bring the key 29 opposite the slot 28 and then released to allow the flange 20 to move the key 29 into the slot 28 to lock the base against rotation on the plate 13 with the

ears

25, 26' and 27 pressed against one side of the plate 13 and the outer periphery of the flange 20 pressed against the other side of the plate.

To facilitate this manipulation of the base the ear 26 is provided with a longitudinally extending rib constituting a stop 31 which terminates at the inner periphery of the flange 2t) and which, as the base is rotated in the plate opening, slides along the curved surface 32 of the slot 23 until it engages the side 34 of the slot 23 and arrests the rotation of the base with the key 29 opposite the slot 28. The key 29 then enters the slot on release of the base as described above.

The shell in of the base is provided with longitudinally extending diametrically opposed ribs 35 and 36 (FIG. 5) on the side of the-flange 2t away from the bulb ll of the lamp to facilitate finger manipulation and rotation of the lamp.

The bottom wall 37 of the shell is comparatively thick for supporting the hollow contact pins 35:, 39 and 40 the inner ends of which are molded into the wall 37. in mounting the base 8 on the lamp bulb 1 one leading-in wire from each pair of leading-in wires is connected to the same contact pin so that this contact pin is common to both filaments of the lamp. The other leading-in wires are each connected to different contact pins. The lamp filaments can then be connected into the electric power circuit separately or together, as is well known. For example, as shown in FIG. 1 of the drawing, the leadingin wires 3 and 5 are both connected to contact pin 38. leading-in wire 6 is connected to contact 39 and leadingin wire 4 is connected to contact pin 4 The leading-in wires are threaded through the hollow contact pins and are soldered or welded to the pins at the outer ends of the latter in mounting the base 8 on the bulb '1.

Conventional electrical connectors provided with female contacts for receiving and gripping the contact pins 38, 39 and 4t) and suitably connected into the electrical system of the vehicle may be used to supply energy to the lamp.

The base 8, with the exception of the contact pins 38, 39 and 46 consists of a tough electrically insulating organic thermoplastic molding material. Thermoplastic nylon (polyamide resins formed of the hexamethylenediamine salt of adipic acid) is a suitable material for the organic part of the base 8 and the flange 29 of this material is sufiiciently flexible. Brass is the preferred metal for the contact pins 38, 39 and 4b.

The

pins

33, 39 and 40 are of different diameter to facilitate making proper connections to the lamp filaments. Of course, when the lamp is of the type having but a single filament connected across a single pair of current inleads extending from the neck 2 of the bulb 1 one of the contact pins may be omitted.

While a species of base embodying the invention has been shown and described, it will be understood that changes may be made in the form and details thereof without departure from the spirit of the invention and within the scope of the appended claim, for example, the inner surface of the shell It may be provided with longitudinally extending ribs at the part thereof covered by the basing cement 9 to increase the strength of the based lamp against rotational forces, when desired, and the base may be made with the relative positions of the flange 20 on the one hand and the

ears

25, 26 and 27 together with the key 29 and the stop 31 on the other hand reveresed on the collar 50 so that the lamp may inserted from the front rather than from the rear of the housing Ill. The housing 11 may be adapted for such front insertion of the lamp by reversal of the support plate 13. In this case the circular part 21 of the keyhole opening may be of smaller diameter than the maximum diameter of the lamp bulb ll because the bulb does not have to be passed through the opening in mounting the lamp on the plate 13. The seal made by flange 2t? around the keyhole opening in the plate 13 is then on the inside rather than on the outside of the housing.

What I claim as new and desire to secure by Letters Patent of the United States is:

A unitary lamp base comprising a molded base body consisting of stifiiy resilient organic thermoplastic material, said body having a cylindrical shell open at one end for receiving and attachment to the neck of a lamp bulb having current carrying inlead wires extending from its neck, the opposite end of the shell being closed by an integral end wall, hollow electrical contacts aflixed to the end wall of the shell and exposed thereat for engagement with terminals of an electric power source and opening into the interior of the shell for receiving the outer ends of the lamp bulb inlead wires, a centering collar integral with the shell, a plurality of arcuate holding ears of difterent dimensions integral with the centering collar, arranged in a common seating plane normal to the longitudinal axis of the shell and extending radially outward at approximately equal angular distances around the collar, and a dished annular resilient flange integral with the collar and disposed with its concavity facing toward the common seating plane of the ears, said flange and said ears being spaced apart longitudinally of said base body a distance sufficient to accommodate and clamp therebetween a lamp supporting Wall of a lamp housing provided with a keyhole opening for said centering collar with the flange flexed against the accommodated wall and sealing the keyhole opening in the housing wall against contaminants, said base body having longitudinally extending protrusions on said collar constituting means for orienting and locking the base in a rotated position on a lamp housing wall, one of said protrusions extending between the flange and the ear of largest dimension to limit the rotation of the base and another of said protrusions extending from an ear of smaller dimension toward said flange and terminating short of said flange to serve to lock the base against rotation on a lamp supporting wall.

References tlited in the file of this patent UNITED ST TES PATENTS 979,927 Brown et al Dec. 27, 1910 1,721,347 Macrae et al July 16, 1929 2,104,808 Neuhaus et al Jan. 11, 1938 2,712,120 Cochran June 28, 1955 2,814,720 Martin Nov. 26, 1957 2,853,595 Bald-win Sept. 23, 1958 2,860,233 Johnson Nov. 11, 1958 2,953,769 Woofter et al. Sept. 20, 1960