US3426314A

US3426314A - Socket and base for lamps

Info

Publication number: US3426314A
Application number: US612114A
Authority: US
Inventors: Raymond Peter Fontana
Original assignee: Duro Test Corp
Current assignee: Duro Test Corp
Priority date: 1967-01-27
Filing date: 1967-01-27
Publication date: 1969-02-04
Anticipated expiration: 1986-02-04

Description

Feb. 4, 1969 R. P. FONTANA SOCKET -ND BASE FOR LAMPS Fired Jan. 27, 1967 FIG. 1

FIG.. 3

FIG. 4

INVENToR RAYMOND PETER FONTANA IIIII AT TORNE S United States Patent O 8 Claims ABSTRACT F THE DISCLOSURE A base for an electric lamp having a pellet of resilient material protruding therefrom which engages the wall of the surrounding socket under pressure and prevents the lamp from becoming loose in or detaching from the socket. The pellet of resilient material also can Ibe used in the socket instead of the lamp base.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to electric lamps and more particularly to a novel ibase and/or socket for a lamp which prevents it from becoming loose in or disengaging from its socket.

In some use applications of electric lamps, particularly where the lamp is subjected to large amounts of vibration such as produced by closely located machinery or other similar equipment, a problem arises in the lamps becoming loose in and/ or falling out of their sockets. This problem is more acute lwith lamps having screw type bases since the continuous threads of the lamp base and socket make it relatively easy for the lamp to `become unscrewed from its socket.

It is of lcourse highly desirable to firmly hold an electric lamp within its socket. Otherwise, the lamp can ibecome loose to a point where it breaks the electrical contact with its socket and becomes inoperative or falls completely out of the socket. The latter is, of course, particularly undesirable since it presents a safety hazard.

SUMMARY OF THE INVENTION The present invention relates to a novel construction of a lamp base and/ or socket which firmly holds a lamp within its socket and prevents it from becoming loose. In accordance with the invention, a pellet of flexible and compressible material is fixed to the lamp base and/ or socket. As the lamp is inserted into the socket the pellet material is compressed between the walls of the lamp base and its socket. The force exerted by the pellet in tending to return to its original shape provides an additional force of substantial magnitude acting to prevent the lamp from becoming loose in its socket. In a preferred embodiment of the invention used with a lamp having a screw type base, the pellet is inserted ibetween two adjacent crests of the screw thread and its portion which lies inside of the base occupies an area which is usually free of other parts in a conventional lamp.

It is therefore an orbject of the present invention to provide means for securing and holding an electric lamp in its socket.

A further object is to provide a lamp base having a pellet of resilient and compressible material held therein for engaging the wall of a socket to securely hold the lamp in the socket.

Another object is to provide a screw-type lamp base having a pellet of resilient and compressible material held therein to securely hold the lamp in its socket.

Yet another object is to provide a socket for an electric lamp having a pellet of compressible material held 3,426,314 Patented Feb. 4, 1969 on the Wall thereof to securely engage a lamp base.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and in the annexed drawings, in which,

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of a portion of an incandescent lamp and its base taken partly in section and showing the subject invention;

FIG. 2 is a side view of the pellet shown mounted in the base of a lamp;

FIG. 3 shows the lamp of FIG. l screwed into the socket; and

FIG. 4 is a side elevational view in section showing a socket having a pellet according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a portion of a conventional screwtype incandescent lamp having an outer glass envelope 11. The bottom portion of the envelope is doubled over to form a reentrant stem 13 through which a pair of

lament wires

15 and 17 pass. The stem 13 seals off the envelope 11 and the envelope is exhausted through a tubulation (not shown) which is tipped off after manufacturing is completed.

The glass envelope 11 is held within a base 20 of electrically conductive material by an amount of a suitalble adhesive 21 placed around the bottom of the bulb. The base 20 has screw threads 22 thereon. In the conventional manner, filament wire 15 is connected at point 24 by solder or `spot welding to the screw-threaded portion of the conductive ibase. The lower portion of the base has a lip 26 which holds a disc 27 of insulating material and an electrically conductive contact member 28 is located thereon. Filament wire 15 is connected to the contact 28. The structure heretofore described is entirely conventional.

As shown in FIG. l, there is an empty area in the base between its bottom and the bottom of the envelope. A hole 30 is drilled or otherwise formed, in the side wall of the base to communicate with the empty area. As shown, the hole is preferably made in the valley between two adjacent crests Of the screw thread.

A pellet 35 of a suitable resilient and compressible material is mounted within the hole 30. The material for the pellet may be, for example, nylon or any other suitable material or synthetic material which has the necessary temperature characteristics. One other suitable material for the pellet is Teflon.

FIG. 2 shows the pellet 35 in greater detail as being in integral, one-piece generally cylindrical unit with a head portion 37 having a central portion of maximum diameter which tapers downwardly on one side to the end of the pellet and on the other side to its reduced diameter center. The diameter of the pellet increases gradually from its center to a base portion 41 having a flat end wall. If desired, the end wall of the base 41 can be cur-ved, or the entire base flattened to a more elliptical shape and curved to more readily conform to the general shape of the area between the screw thread crests.

During manufacture, that is either before or after the envelope is fastened to the base, the head 37 of the pellet is inserted from the outside of the base into the hole 30 and it is pushed in until the edge of the base wall surrounding the hole contacts the body portion. As seen, the inwardly sloping Wall of the valley between the two crests of the screw thread generally conforms to the tapering shape of the pellet body. The maximum diameter portion of the pellet head 37 is slightly larger than the diameter of the hole 30. This provides a pressure or snap t for the pellet into the hole and prevents the pellet from falling out. The body portion 41, being of larger diameter than the hole 30, prevents the pellet from being pushed into the'base.

`PIG. 3 shows the base of a lamp made in accordance with the subject invention screwed into a socket. As can be seen, the material of the pellet 35 is compressed by the screw threads of the socket. Since the head of the pellet preferably extends only to, or slightly beyond, the crest of the thread and since the pellet preferably occupies only a relatively small portion of the total eX- ternal area of the base, the lamp can be easily screwed into the socket and the pellet does not interfere with the electrical contact between the base and socket. Also, materials such as nylon and Tellon are relatively smooth and provide a good bearing surface.

The compressed material of the pellet is wedged between the mating threads of the base and socket. Due to this, and also due to the force exerted by the material in trying to return to its normal shape, the lamp is securely locked to the socket.

FIG. 4 shows a socket having a pellet 35 inserted in a hole 30a therein between two screw threads, the conductive portion of the socket being held in an insulated housing 50. This conguration has an advantage because there are a number of places where the pellet can be inserted, as compared to the base of a lamp which has limitations such as the glass and the base lead wires.

While the pellet can be inserted either in a lamp base or a socket, it should be understood that several advantages accrue to both embodiments. In the case of the lamp, the pellet can be inserted in the base of any larnp and this lamp locked tight to any socket of any fixture. Of course, this requires one pellet for each lamp and the additional manufacturing step of making a hole in the lamp base. On the other hand, when a pellet is used in a socket, all lamps used in that particular socket will be ad-vantageously locked in. Also, as should be apparent, a pellet can be used on both the lamp base and the socket members.

While the invention has been shown with a screw type base, it should be understood that it also can be advantageously used with other types of bases, e.g., bayonet.

While preferred embodiments of the invention have been described above, it will be understood that these are illustrative only, and the invention is to be limited solely by the appended claims.

What is claimed is:

1. The combination of an electric lamp having a base member and a socket member to which said base member is to be secured to make electric contact therewith,

a piece of resiliently compressible material, means for securing the piece of material to one of said base and socket members to engage the other of said members when the lamp is in the socket, said piece of material shaped to permit normal insertion and removal of the lamp base from the socket and being compressed between said two members when the lamp base is within the socket to securely hold the lamp to the socket.

2. The combination of claim 1 wherein said piece of material is in the shape of a pellet and said securing means comprises the wall of one of said members formed with a hole through which the pellet protrudes toward the wall of the other member, said pellet being held by the wall of said one member surrounding the hole formed therein.

3. The combination of claim 2 wherein the wall of the socket member has the hole formed therein for holding the pellet.

4. The combination of claim 2 wherein the wall of the lamp base member has the hole formed therein for holding the pellet.

5. The combination of claim 4 wherein the base member is of the screw type and the hole is formed in said base between adjacent crests of the screw thread in which the piece of material is held.

6. The combination of claim 3 wherein the socket member is of the threaded type for a screw type lamp, and a hole is formed in a wall of said socket in which the piece of material is held.

7. The combination of claim 5 in which said piece of material is in the shape of a pellet having a reduced diameter tip portion which permits the pellet to be inserted into the wall from outside of the lamp base.

8. The combination of claim 7 in which said piece of material is in the shape of a pellet having a reduced diameter intermediate portion which permits the pellet to be held within said hole by the surrounding wall.

References Cited UNITED STATES PATENTS 1,082,397 12/1913 Blass 339-84 2,212,728 8/1940 Blood 339-93 3,000,231 9/ 1961 Cochran 74-502 FOREIGN PATENTS 344,730 11/ 1936 Italy.

MARVIN A. CHAMPIIO'N, Primary Examiner.

JOSEPH H. M. MCGLY-NN, Assistant Examiner.

U.S. C1. X.R. 285-404; 339-93