US3308420A - Lamp socket shell with integral tangs - Google Patents

Description

M r 7, 1967 R. E. FlTZ GERALD LAMP SOCKET SHELL WITH INTEGRAL TANGS Filed Dec. 21, 1964 Inveuioz' R021 ez'iloEvlFfiz Gerald, Hit

United States Patent 3,308,420 LAMP SOCKET SHELL WITH INTEGRAL TANGS Robert E. Fitz Gerald, Quincy, Mass, assignor to United- Carr Incorporated, Cambridge, Mass., a corporation of Delaware Filed Dec. 21, 1964, Ser. No. 419,800

- 1 Claim. (Cl. 339-176) This invention relates generally to lamp sockets and more specifically to lamp sockets engaged within a housing or casing.

An early method of engaging the body portion of a socket with a housing was to rivet a plug button having a central aperture to the end of the body portion remote from the contact portion of the socket and then engage the housing over the fingers of the plug button.

An object of the present invention is to provide the inner conductive shell of a socket with outwardly extending tab or struck portions radially positioned for engagement within an outer housing.

A further object of the present invention is to provide stop means which are associated with the conductive shell.

A still further object of the present invention is to provide an insulating, snap engageable means, engageable with the end of the conductive shell remote from the bulb-receiving end to act as a stop means and as a protective insulator.

Other objects of the invention will, in pant, be obvious and will, in part, appear hereinafter.

In the drawings:

FIG. 1 is a side elevation of the conductive shell;

FIG. 2 is a bottom plan view of the conductive shell shown in FIG. 1;

FIG. 3 is a top plan view of the external stop means;

FIG. 4 is a cross section of the socket assembly;

FIG. 5 is a cross section of a variation of the assembly shown in FIG. 4 showing the lower portion of the bulb in full and the lead in full broken away; and

FIG. 6 is a bottom plan of the variation shown in FIG. 5 with the lead, in section.

In the drawings, FIGS. 1 through 4, there is shown a socket shell 10 formed of an electrically conductive material, tubular in configuration and open at both ends. A pair of bayonet slots 12 are formed in spaced, offset relationship in the shell 10 adjacent the first of the open ends. A series of spring fingers 14, formed from the material of the shell 10, are provided which are spaced from the bayonet slots 12 and the second opened end and positioned therebetween. The fingers 14 are angled outwardly from the shell 10 and are positioned around the circumference thereof in spaced relation to each other. The embodiment also discloses that a knuckle 16 may be provided on the fingers 14 by including diverging and converging portions, as shown in FIG. 4.

The wall of the shell 10 adjacent the second opening remote from the bayonet slots 12 can be slit to form a series of spaced tangs which may then all be bent inwardly toward the axis of the shell 10 and in right angle relation to the remaining portion of the shell 10' to form a stop means 18.

The outer casing 20 which includes a tubular body open at one end and closed at the other has a slot 24 formed at a predetermined position through the outer casing 20 between the closed and opened ends. The housing 20 may be formed of a metallic material such as aluminum or steel. The shell 10 is formed of an electrically conductive material such as cold rolled steel; however, it is preferable to have it formed of some material which will allow resiliency in the fingers 14. This resiliency may be imparted to the cold rolled steel, as is well known in the art, by heat treating it. The fingers 14 are formed so as to be spaced on three sides from the shell 10 as shown in FIG. 1.

An external stop means 26, formed of a nonconductive material, comprising a circular base portion 28, having a diameter greater than the external diameter of the shell 10, and having a stud portion extending from the base portion 28 and including a neck portion 30 and a bead portion 32 connected to said base portion through the neck portion 30. Frequently in assemblies of this type the lead 38 will lose the insulation covering the part of the wire near the contact member 36. The use of nonconductive material for the external stop means 26 will prevent a short circuit which might occur between the accidentally bared wire of the lead 38 and the stop means 18. An aperture 34 is formed axially through the stud portion and the base portion 28, as shown in FIGS. 3 and 4. The circumferential bead 32 has a diameter greater than the diameter of the neck portion 30 and less than the diameter of the base portion 28.

The contact assembly comprises a conventional capped contact member 36 soldered or crimped to a bared portion of the insulated wire lead 38. A compression spring 42 circumscribes in spaced relation a portion of the contact member 36 and a portion of the lead 38. An insulating collar 44 is interposed between the cap of the contact member 36 and the spring 42 as shown in FIG. 4. The electrical contact assembly may then be passed into the shell 10 and the wire lead 38 is passed through the axial aperture 34 in the external stop means 26 as well as through the opening provided by the stop means 18. The external stop means 26 may be engaged to the shell 10 prior to the assembly of the contact assembly with the shell 10 or subsequently thereto as desired. The engagement of the shell 10 and the external stop means 26 is brought about by snapping the head 32 through the aperture provided by the stop means 18 where upon the neck 30 of the external stop means 26 is engaged by the edges of the tangs of the stop means 18 as shown in FIG. 4. The external diameter of the bead 32 is slightly greater than the diameter of the circle defined by the inner edge of the stop means 18.

A variation of the assembly is shown in FIGS. 5 and 6. In this case the shell 10a is the same as the shell 10 including fingers 14a which are constructed similar to the fingers 14. The difference between the two assemblies is that the stop means 18a includes alternate tabs which are bent inwardly. Other tabs 46 are bent outwardly to provide an interrupted external flange, thereby making the internal and external stop means integral with the shell 10a.

I claim:

A lamp socket assembly comprising a tubular shell, an outer casing, said shell being formed of an electrically conductive material and having open ends and having a series of resilient fingers formed around the circumference thereof and extending therefrom, one open end being bent inwardly to provide an internal shoulder, and an insulating external stop means comprising a base portion and a stud portion extending from said base portion, said base portion and said stud portion having an aperture formed therethrough an insulating collar having a hole formed therethrough lying within said tubular shell with the cap of a contact member lying on the surface of said collar, facing away from said stop means and said contact member extending through the hole in aid collar and having at least one lead extending through the aperture in said external stop means, said collar and said internal shoulder having a spring means therebetween, said spring means circumscribing said lead, said stud portion being in engagement with said internal shoulder and said fingers of said shell being in sliding engagement with the inner surface of said outer casing.

References Cited by the Examiner UNITED STATES PATENTS 1,982,627 12/1934 Baum 339-180 X 2,283,934 5/1942 Jorgensen 339180 X 2,712,120 6/1955 Cochran 339-128 10 EDWARD c. ALLEN, Primary Examiner.

W. DONALD MILLER, Examiner.

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