US2721984A

US2721984A - Plural lamp sockets

Info

Publication number: US2721984A
Application number: US439344A
Authority: US
Inventors: Zion Moses
Original assignee: Lionel Corp
Current assignee: Lionel Corp
Priority date: 1954-06-25
Filing date: 1954-06-25
Publication date: 1955-10-25
Anticipated expiration: 1972-10-25

Description

Oct. 25, 1955 z o 2,721,984

PLURAL LAMP SOCKETS Filed June 25, 1954 3 INVENTOR.

ATTORNEY.

United States Patent PLURAL LAMP SOCKETS Moses Zion, Brooklyn, N. Y., assignor to The Lionel Corporation, New York, N. Y., a corporation of New York Application June 25, 1954, Serial No. 439,344

2 Claims. (Cl. 339-164) The present invention relates to plural lamp sockets and is more particularly directed toward die-cast lamp sockets suitable for use with a plurality of pin type lamps to support the same and form a common ground for the lamp pins.

According to the present invention, the entire socket structure, including the slot arrangement to accommodate the pins on the lamps, the chambers for the lamp bases and the abutments for the lamp protracting springs, is formed in a single die casting. Such die casting elements replace the usual sheet metal, multiple piece lamp sockets employed for this purpose.

Other and further objects will appear as the description proceeds.

The accompanying drawings show, for purposes of illustrating the present invention, an embodiment in which the invention may take form, together with a method of manufacturing the same, it being understood that the drawings are illustrative of the invention rather than limiting the same.

In these drawings:

Figure 1 is an exploded perspective view showing a lamp socket, lamp and associated parts;

Figure 2 is a rear elevational view of a vdouble lamp socket with parts in section on the line 22 of Figure 3;

Figure 3 is an elevational view with parts in section on the line 33 of Figure 2;

Figure 4 is a sectional view illustrating the lamp and lamp socket assembled;

Figure 5 is an enlarged perspective view illustrating the path taken by the pin in entering the pointed slot;

Figure 6 is a view illustrating the mold parts employed in making the die casting, the mold being open;

Figure 7 is a sectional view through the closed mold, showing the casting in the mold;

Figures 8 and 9 are fragmentary sectional views on the lines 88 and 99 of Figure 6; and

Figure 10 is a fragmentary sectional view on the line 1010 of Figure 7.

A conventional miniature lamp is indicated at 10. Such a lamp has a metal base 11, a center contact 12 and two pin contacts 13.

The drawings illustrate a double lamp socket, such as would be employed in the semaphore signal of a toy railroad system. It has two sockets, indicated generally at 20-20, for the lamps. Any number of sockets may be used and they may be disposed to form various characters, such as letters, numbers or the like.

Each socket 20 is in the form of a recess in a die-cast body 21. This recess has

cylindrical walls

22, 22, which occupy less than one-half the surface of a circular cylinder. These cylindrical wall portions are separated by slots having narrow front portions 23 and wide rear portions 24. One wall of each slot is straight, as indicated at 25, while the other wall is stepped, as indicated at 26a, 26b and 26c. The portion 26b forms a reverse angled step, which forms a nose at 27 and a recess at 28.

At the bottom of the socket forming recess is a rear opening 29 and inwardly extending

bottom walls

30, 30.

At the front or open end of the socket, the casting is provided with

beveled surfaces

31, 31, which extend to the straight sides of walls 25 of the slots. These beveled surfaces do not, however, extend to the side wall portions 26a of the slots, as indicated at 32. The latter form stops for the lamp pins.

The external configuration of the socket will vary according to the use to which the socket is to be put. It is here shown in the form of a two-lamp toy semaphore signal, and the casting is provided with

visors

32, 32, and lugs 33 adapted to receive mounting screws.

A lead wire 35, Figure 1, is secured to a center contact 36 carried on an insulating washer 37, the wire passes through a coiled spring 38 and an apertured insulating washer 39 and the aperture 29 in the casting, and the parts will normally be held in place when the wire is secured to a terminal.

In use, the lamp base is passed into the socket and the pins 13 brought against the beveled surfaces 31. Turning the lamp causes the pins to travel along 31 until, as shown in Figure 5, they abut the side portions 26a of the slots. The pressure on the lamp forces the pins in past the nose portions 27 and they readily pass into the recesses 28. The spring then holds the lamp in place.

The socket is made in a die casting mold. The part 50 at the left, Figures 6 and 7, has the desired configuration to form the face of the socket, including an oblique fillet at 51, which forms the bevel 31 and bifurcations 52--52, shown in cross section in Figure 8. These have arcuate sides 52a and straight sides 52b and a diameter equal to the diameter of the recess 22 of the socket to be produced. The sides 52b are spaced the width of the wide portions 24 of the slots.

The other mold part 53, shown at the right of Figures 6 and 7, has a blade 54 of a width to pass between the straight sides 52b of the bifurcations 52 on the mold part 50. The major portion of this blade is the central part of a cylinder of larger diameter than the cylinder forming the bifurcations 52, and of the width of the wide portions 24 of the slots, so as to form such wide portions. The front end of the blade 54 is cut back at the opposite corners, as indicated at 55, to be of the diameter of the bifurcations 52 for a sufficient depth to form the narrow side portions 26a of the slots, and is beveled, as indicated at 56, to provide the oblique surfaces 26b.

When the mold is closed, as shown in Figure 7, the cavity formed by the blade, the bifurcations and adjacent fillets is such as to form the casting of the desired contour. The remainder of the mold is arranged to give the die casting the desired external contour, fitting it for a particular use or mounting arrangement.

This application is a division of my application Serial No. 220,404 filed April 11, 1951, issued as Patent 2,682,650, June 29, 1954.

Since it is obvious that the invention may be embodied in other forms and constructions within the scope of the claims, I Wish it to be understood that the particular form shown is but one of these forms, and various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is:

1. A plural lamp socket adapted to receive and support a plurality of lamps of the type having oppositely extending pins and provide a common ground for all the lamps, said body being in the form of a die casting having a plurality of recesses opening in a common direction, the recesses having cylindrical walls, each recess having in the walls thereof two longitudinally extending, pin-receiving grooves diametrically opposite one another, each groove having a straight side wall and a stepped side wall making the inner portions of the groove wider than the outer pora a Y 7 4 tions, the stepped walls including reverse angled steps I References Cited in the file of this patent into which the pins-are movable to ground the lamps when UNITED STATES PATENTS the lamps are lnserted and turned angularly.

2. A plural lamp socket such as claimed in claim 1, 1,796,694 S11v3 17, 1931 wherein the bottom of each recess has inwardly extend- 5 1,922,687 Juergens et 1933 ing shelves and a wire receiving opening.