US3784867A

US3784867A - Lamp

Info

Publication number: US3784867A
Application number: US00295669A
Authority: US
Inventors: J Dupree
Original assignee: DUPREE Inc
Current assignee: DUPREE Inc
Priority date: 1972-10-06
Filing date: 1972-10-06
Publication date: 1974-01-08
Anticipated expiration: 1991-01-08

Abstract

A lamp having a bulb fixed in the housing and a moving socket engaging pin spring loaded to an extended position. A housing with an inner insulating sleeve molded in place in an outer metal sleeve with a cup-shaped conductor pin retained by the housing and receiving a spring welded to a bulb lead, with the springbulb lead connection encapsulated and with the bulb cemented in the housing with the other lead spot welded to the outer sleeve.

Description

Inn 3,784,867

1 1 Jan.8, 1974 United States Patent [1 1 Dupree 313/113 Michel et 313/318 X Kawate 313/318 Jacobs 313/318 68 8 6365 99,99 wmww 0400 27 0 7 942 83004 2 3222 1 1 LAMP [75] Inventor: James N. Dupree, Los Angeles,

Calif.

[73] Assignee:

[22] Filed:

Dupree, Inc., South El Monte, Calif.

' Primary ExaminerRud0lph V. Rolinec Oct. 6, 1972 [21] Appl. No.: 295,669

Assistant ExaminerSaxfield C hatmon, Jr. AttorneyFord W. Harris, Jr. et al.

[57] ABSTRACT A lamp having a bulb fixed in the housing and a moving socket engaging pin spring loaded to an extended position. A housing with an inner insulatin g sleeve h a cupg and re- 0 0 5 0 N &2 0 33 B 5 I33 5M2 Jl. 32 H m .3 "Q "m3 mh c an we us I. 00 d ..l Mk .[F 1.1. 18 55 ll molded in place in an outer metal sleeve wit shaped conductor pin retained by the housin ceiving a spring welded to a bulb lead, with the springbulb lead connection encapsulated and with the bulb cemented in the housing with the other lead spot 313/318 welded to the outer sleeve. 313/318 313/318 X 2 Claims, 2 Drawing Figures S m m W N mm m m A P n .aE wm 6 Ban mw e DO rT ao kSDLF e E087 T73.4 www U994 035 359 l 019 33 rl 322 LAMP This invention relates to lamps or light bulbs adapted to be removably mounted in sockets and in particular,

to a new and improved lamp which may be directly substituted for the lamp shown in the US. Pat. to Dupree No. 3,530,330.

The aforementioned Dupree patent discloses a lamp having a bulb fixed in a housing and a pin movable in the housing, with a spring urging the pin to an outward position. The lamp is intended for use with a socket having a fixed center contact with the force for maintaining the electrical contacts being provided by the spring within the lamp.

The prior art lamp has been satisfactory in meeting some of the problems encountered in the use of lamps and sockets, particularly small size lamps intended for installation in positions with limited access for socket maintenance and repair. However some problems have been encountered in quantity high production manufacture of the lamps, particularly the very small lamps which may be in the order of 3/32 inch diameter and one-half inch long. Accordingly it is an object of the present invention to provide a new and improved spring-loaded lamp and a new and improved process of making such lamps. It is a particular object of the invention to provide a lamp housing having an inner insulating sleeve molded in place in an outer metal sleeve. A further object is to provide such a lamp with a cupshaped conductor pin sliding within the housing and receiving the spring in the pin cup.A particular object of the invention is to provde a new and improved springbulb lead connection with a closed turn spring and an encapsulated joint. One additional object of the invention is to provide a new and improved mechanical and electrical connection between the bulb and housing for holding the bulb in place and making an electrical connection to the housing.

Other objects, advantages, features and results will more fully appear in the course of the following de scription.

In the drawing:

FIG. 1 is a sectional view ofa partially assembled lamp and incorporating the presently preferred embodiment of the invention; and- FIG. 2 is a view similar to that of FIG. 1 showing the lamp completely assembled. l

The lamp includes a bulb with leads 11 and 12, a spring 13, a conductor pin 14, and a housing 15 with an outer metal sleeve 16 and an inner insulating sleeve 17. l

The housing outer sleeve 16 preferably is drawn from a metal sheet, typically brass sheet, into a sleeve or tubular configuration. The sleeve 16 has an upper portion 20 for receiving the bulb 10 and terminates in a flange 21. The sleeve 16 also has a lower portion 22 for receiving the inner sleeve, with opposed circular projections or knobs 24 for engaging corresponding passageways in the socket, such as that shown in the aforementioned US. Pat. No. 3,530,330. An inwardly turned flange 25 at the lower end of the outer sleeve 16 provides engagementwith the inner sleeve 17.

The inner sleeve 17 is formed of an electrical insulating material and is molded in place in the outer sleeve 16, with interengagement of the inner and outer sleeves at the knobs 24 and flange 25 locking the two pieces.

together. The inner sleeve 17 has a zone 26 for receiving the conductor pin 14, with a shoulder 27 for limiting movement of the pin, and an opening 28 for receiving the tip 29 of the pin 14.

- The conductor pin 14 has a cup 33 for receiving the spring 13 with the tip 29 depending from the cup. The pin preferably is made by drawing from a metal sheet producing the cup and tip in one piece in a multi-stage eyelet machine, providing high speed and high volume production for reduced cost.

The lower end of the spring 13 rests in the cup 33 of the pin 14, preferably with a slight interference fit for better electrical contact. A closed turn 34- is provided at the upper end of the spring 13, with the tip 35 projecting upward and spot welded to the bulb lead 11. The bulb lead 12 is bent upward alongside the bulb 10.

After the lead 12 has been shaped and the spring has been connected to the lead 11, the space between the bulb l0 and the closed turn 34 of the lamp is filled or encapsulated with a potting material 37, typically a conventional epoxy potting compound. The potting material is introduced into the very small space by a hypodermic needle and the closed turn 34 of the spring functions to prevent movement of the potting material along the spring, which would occur by capillary action with a conventional open turn spring. After curing, the encapsulated joint 37 provides the mechanical strength for the connection betweenthe bulb and spring, relieving the spot welded electrical connection of the mechanical stress.

Next, a band of cement, typically a conventional epoxy cement, is applied around the bulb l0 and lead 12, the spring is inserted into the cup of the conductor pin, the pin is slid into the zone 26 of the inner sleeve, with the cup engaging the shoulder 27, as seen in FIG. 2, and the bulb is inserted to the position shown in FIG. 2. The bulb and housing are maintained in this position while the cement hardens, after which the end 36 of the lead 12 is bent outward and connected to the flange 21 of the housing by spot welding at 40. The surplus end of the lead 12 is broken off, completing the assembly of the lamp.

This new and improved lamp permits the use of drawn sheet metal parts for the housing outer sleeve and for the conductor pin. This is particularly advantageous with regard to the pm which normally is made as a machine part and does not incorporate a cup for receiving and retaining the lower end'of the spring. The design also permits molding the inner insulating sleeve in place in the outer sleeve, rather than requiring the separate manufacture of an insulating sleeve and subsequent assembly and joining of the two pieces to produce a housing. Further, the design permits the use of spot welded connections for the'leads in lieu of the conventional soldered connections, with the lamp construction taking the mechanical strain at the electrical connections.

I claim:

1. In a spring loaded lamp adapted to be mounted in a socket in locking engagement, the combination of:

a bulb having first and second leads;

a coil spring having a first end welded directly to said first lead and having a second free end, said spring having a closed turn adjacent said first lead;

a conductor having a spring receiving cup at one end and a socket contacting pin at the other end;

a tubular housing comprising interengaging outer metal and inner insulating sleeves, with said inner sleeve molded in place in said outer sleeve and having a central zone terminating in a shoulder for engaging said cup and having an opening for said socket pin.

said outer sleeve having an outwardly turned rim and with said bulb positioned in said outer sleeve with said second lead bent 180 and positioned between said bulb and outer sleeve, with the second lead end overlying and welded directly to said rim; and

a solid potting material positioned between said bulb and spring about said leads and filling said closed turn mechanically supporting said spring and leads and electrically insulating said leads from each other;

with said conductor in said housing sliding in said zone with said spring free end in said cup and urging said pn into said housing.

2. A method of making a spring loaded lamp having a bulb fixed in a housing with a moving conductor pin for contacting a socket, including the steps of:

molding an inner insulating sleeve in place in an outer metal sleeve to form a housing; welding one end of a spring directly to a first bulb lead; encapsulating the space between the bulb and a closed turn of the spring with a potting material; positioning the bulb and spring and a conductor pin in said housing, with a second bulb lead bent between the bulb and housing and exposed at the bulb end of the outer sleeve of the housing; cementing the bulb in the housing outer sleeve; and

welding the exposed second lead to the sleeve.

'o iosc b STATES PATIENT. OFFICE CERTIFICATE 0F CGRRECTION Patent No. 3,784 8 67 1L Dated Jammy 8, 1974 lnventor(s) b It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[75] Inventor: "Los Angeles" should be South El Monte-;

and

Column 3, line 17, Claim 1, "pm" should be -pin-- (Claim 8,

line 26 of amendment dated July 6, 1973).

' sighed ami sealed this 1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR, C, MARSHALL DANN Attesting Officer Commissioner of Patents

Claims

1. In a spring loaded lamp adapted to be mounted in a socket in locking engagement, the combination of: a bulb having first and second leads; a coil spring having a first end welded directly to said first lead and having a second free end, said spring having a closed turn adjacent said first lead; a conductor having a spring receiving cup at one end and a socket contacting pin at the other end; a tubular housing comprising interengaging outer metal and inner insulating sleeves, with said inner sleeve molded in place in said outer sleeve and having a central zone terminating in a shoulder for engaging said cup and having an opening for said socket pin, said outer sleeve having an outwardly turned rim and with said Bulb positioned in said outer sleeve with said second lead bent 180* and positioned between said bulb and outer sleeve, with the second lead end overlying and welded directly to said rim; and a solid potting material positioned between said bulb and spring about said leads and filling said closed turn mechanically supporting said spring and leads and electrically insulating said leads from each other; with said conductor in said housing sliding in said zone with said spring free end in said cup and urging said pn into said housing.

2. A method of making a spring loaded lamp having a bulb fixed in a housing with a moving conductor pin for contacting a socket, including the steps of: molding an inner insulating sleeve in place in an outer metal sleeve to form a housing; welding one end of a spring directly to a first bulb lead; encapsulating the space between the bulb and a closed turn of the spring with a potting material; positioning the bulb and spring and a conductor pin in said housing, with a second bulb lead bent 180* between the bulb and housing and exposed at the bulb end of the outer sleeve of the housing; cementing the bulb in the housing outer sleeve; and welding the exposed second lead to the sleeve.