US 3425027 A
Description (OCR text may contain errors)
Jan. 28, 1969 E. c. UBERBACHER ET AL. PLUG-IN PANEL LAMP Filed July 5, 1967 INVENTORS- C. UBERBACHER S. LOTT JR.
BY w ATTORNEY EDWARD JAMES United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE This specification describes a lamp with a bulb which with its leads is held in position in a housing by a sleeve that surrounds the housing and is shrink-fitted to grasp the bulb and the leads.
Background of the invention The present invention relates to the assembly of electrical components and more particularly to the assembly of lamps that can be plugged into panels or the like.
The most unreliable portion of a plug-in lamp is usually the light bulb itself and when the light bulb fails the whole lamp is generally thrown away. Therefore, it is desirable to minimize the cost and number of ancillary parts needed to provide the plugging in capability. These ancillary parts not only add to the cost of the lamp but in addition decrease reliability of the lamp since they themselves may fail and they require the attaching of the bulb or its leads to contacts or terminals thereby int-roducing the possibility of damaging the bulbs or the leads during manufacture.
Therefore it is an object of the present invention to provide a new lamp.
It is another object of the present invention to provide new means for mounting small lamps.
It is still another object of the invention to provide means for plugging lamps into panels.
Summary -In accordance with the present invention a new panel lamp is provided which is electrically and mechanically reliable, yet is simple and inexpensive to fabricate. In this lamp, the front end of a bulb extends from an opening at one end of a housing While the leads for the bulb extend through holes in the other end or base of the housing and are bent around the peripheral edge of the housing so they are against the sides of the housing. A sleeve is then shrink-fitted to the housing and the bulb so as to retain the bulb in the housing and the leads in position between the housing and the sleeve. This lamp can therefore be plugged in by inserting pins through the holes in the base of the housing so that the pins are forced up against the leads. Furthermore, the lamp consists of only three parts, the bulb, the housing and the sleeve, and there is no need for the usual glueing or mechanical retention schemes to hold the bulb within the housing.
Description of the drawing The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawing which is a perspective of a lamp that is broken away to show its construction.
Description of the preferred embodiment Referring to the drawing, a bulb 10, having filament 12 with leads 14 which pass through the glass enclosure 7 of the bulb 10, is mounted in a cavity of a cylindrical ice nylon housing 16 with the front end of the bulb 10 protruding from the open end of the housing 16 and the back end of the bulb 10 positioned against the closed end of the housing 16. The leads 14 for the bulb 10 extend from the back of the bulb through openings 18 in the closed end or base 20 of the housing 16 and are bent around the base end of the housing so that their tips 14a are positioned axially against the side wall of the housing 16. With the bulb 10 so mounted within the housing 16, the housing and the bulb are placed within a plastic sleeve 22 which is then shrink-fitted to the housing 16 and the bulb 10. The sleeve 22 is long enough to overlie a portion of the exposed end of the bulb 10 and the tips 14a of the leads. Therefore, when the sleeve 22 is shrink-fitted, it tenaciously grabs the bulb at the open end of the housing so the bulb is retained within the housing and also holds the tips 14a between the sleeve 22 and the housing 16 in the desired position.
A suitable material for the tubing forming sleeve is a. heat shrinkable polyvinyldinefluoride which is bought in an oversized diameter and placed around the housing 16 and the bulb 10 as previously described. Then the sleeve is heated by a hot air blower or a low temperature oven until the sleeve shrinks and becomes fitted to the housing and the bulb are placed within a plastic sleeve 22 assembly.
A liquid expandable plastic tubing may be used as the material of the sleeve 22 in place of the heat shrinkable plastic. If such a liquid expandable plastic is used, the sleeve is bought in its desired final dimensions, wetted so that it expands to fit on the bulb 10 and housing 16 and then is allowed to dry after it has been placed on the bulb 10 and housing 16 so that it shrinks back to its initial dimensions and grasps the bulb and the leads as described previously.
Once assembled, the lamp may be inserted on pins such as pins 24 by forcing the pins through the openings 18 for the leads. Preferably the openings 18 are smaller in diameter than the pins 24 so as to force the leads 14 against the side walls of the openings and thereby obtain a good electrical contact between the pins 24 and the leads 14. Nylon was chosen as the material of the housing because it offered lubrication for the pins and presented the proper feel when the pins were inserted through the housing. However other suitable materials can be used if desired.
While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
1. In a lamp assembly having a light bulb projecting from one end of a housing with contacts at its other end for making electrical connections to the light bulb, the improvement which comprises:
leads for the light bulb that pass through apertures in said other end and have tips extending along the outside of the housing; and
a sleeve which is positioned around the housing so that it overlies the bulb at the one end of the housing :and the tips at the other end of the housing andis shrink-fitted to said housing so as to clamp the tips between the sleeve and the housing and the bulb in the housing.
2. The lamp of claim 1 wherein said sleeve is a heat shrinkable material.
3. The lamp of claim 1 wherein said sleeve is a liquid "expandable material.
4. The lamp of claim 1 wherein said apertures are receptacles for electrical probes that provide excitation to the bulb.
References Cited UNITED STATES PATENTS Capel 339-103 X 5/1967 Booker 174-84 5/1961 Williams 340--38l FOREIGN PATENTS 1/1957 France.
RICHARD E. MOORE, Primary Examiner.
US. Cl. X.R.