US2910310A - Ball and socket swivel for an electric light receptacle - Google Patents

Description

R. A. MULAC Oct. 27, 1959 BALL AND SOCKET SWIVEL FOR AN ELECTRIC LIGHT RECEP'I'ACLE Filed Dec. 6, 1957 United States Patent BALL AND SOCKET SWIVEL FOR AN ELECTRIC LIGHT RECEPTACLE Rudolph A. Mula'c, Chicago, Ill.

Application December 6, 1957, Serial No. 701,003

4 Claims. (Cl. 285-91) be interposed between an electric light receptacle and the support for the receptacle, and which will allow universal swiveling of the electric light receptacle without exposing any electrical wires at or around the swivel joint.

It is a further object of the present invention to provide a swivel joint of the above mentioned character wherein the wires for carrying electric connections to the light bulb receptacle extend lengthwise through the ball and socket connection.

It is a still further object of the present invention to provide a ball and socket mechanism of the above mentioned character that provides a screw threaded mount for receiving an electric light bulb receptacle and which is also screw threaded to provide for mounting for the ball and socket mechanism on a lamp support in such manner as to permit universal swiveling of the electric light bulb receptacle and which will also permit screwing or unscrewing of the electric light bulb receptacle on to or off of the ball and socket mechanism without requiring any special tools or the like for holding the ball and socket mechanism in position.

The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawings forming a part thereof.

In the drawing:

Figure 1 is a longitudinal view, in partial section, showing the mechanism of the present invention as applied between an electric light bulb receptacle and a conventional support therefor;

Figure 2 is a top plan view of the ball and socket mechanism;

Figure 3 is a longitudinal sectional view taken along the line 33 of Figure 2;

Figure 4 is a longitudinal sectional view taken along the line 44 of Figure 2 and looking in the direction of the arrows; and

Figure 5 is a sectional view taken along the line 5--5 of Figure 4.

Like figures designate like parts throughout the different figures of the drawing.

In Fig. 1 there is shown in a fragmentary manner an incandescent electric light bulb 1 having a male screw type base adapted to be threaded into a conventional electric light bulb receptacle 3 which may or may not have a switch 4 and which terminates in a female threaded neck 6 that is adapted to be threaded on to the top of a threaded type support 8, and is to be locked in place as by a screw 9.

The electric wires for establishing the connections within the receptacle extend into the receptacle through the support 8 and neck 6. In the present instance, a ball and socket mechanism 10 of the present invention is interposed between the support 8 andthe neck 6.

The ball and socket mechanism includes a ball part 12 which in this instance is the upper part, and a socket forming part 14 which in this instance is the lower part.

The ball forming part 12 has an externally threaded neck 15 that terminates in an inverted fruszto-conical base 16 which in turn terminates in a ball or spherical part 18. A longitudinal bore 20 extends through the bore part 12 concentric with the axis of the threads on the neck 11.5. In the periphery of the ball part 18 there is formed a groove 22 substantially V-shaped that extends along an arc which is a great circle of the sphere or ball part 18, said great circle being centered in a plane that includes the longitudinal axis of the bore 20. The groove 22 is of a length approximately degrees along the periphery of the ball 13, although the extent of this are may .be greater or less than 90 degrees depending upon the amount of tilting that is to be permitted to the axis of the neck 20.

The socket part 14 of the ball and socket mechanism consists of a lower or base portion 25 that is internally threaded at its bottom at 26. The pitch of the threads 26 is the same as the threads 15 which is the same as the pitch of the threads at the top of the support 8. As a result of this arrangement the threads 26 may be threaded on to the support 8 for mounting the ball and socket mechanism, and the neck 6 of the electric light receptacle 3 may be threaded on the threads 15 for mounting the electric light receptacle. The base portion 25 has a longitudinal bore 27 therethrough through which are passed the electrical conductors for the electric light bulb, and has at the top thereof a counter bore 23 that provides a peripheral shoulder 29 that constitutes a seat for a spring 301. A ring 32 is located within the counter bore 23 and constantly pressed upwardly by the spring 30, the ring 32 being curved on the inside to coincide with the surface of the ball 18 so that the ball 18 is free to slide along the inner surface of the ring 32. The top of the base 25 is externally threaded as indicated at 33, to receive a female threaded cap 34 which in Figures 3 and 4, is in inverted position. The top end 35 of the cap 34 has an opening that seats on the ball 18, said opening being of a diameter less than the diameter of the ball 18 and greater than the maximum diameter of the frustoconical base 16, so that the neck 15 and base 16 of the ball part 12 may be inserted through the central opening in the top end 35 of the cap 34, the upward movement thereof being limited by the ball 18.

When the cap 34- is screwed into position so that the bottom of the cap rests on the external peripheral shoulder 33 of the base 25, there is an annular space 38 between the underside of the cap 34 and the top of the base 25. This space constitutes a raceway for a ball bearing 4% that also extends into the groove 22 and is confined between the groove 22 and the groove or annular space 38. The difference between the outside diameter of the ball 18 and the inside diameter of the cap 34 at the annular space 38 is less than the diameter of the ball bearing 40.

After assembly of the parts thus far described, the cap 35 is drilled to form a hole 44. This hole extends through the top 35 of the cap 34 and through the threads between the cap 34 and the base 25. After this hole is formed, a pin 45 is driven into this hole until the top of the pin is flush with the outside surface of the top 35.

The pin 45 serves a number of purposes. First it looks the cap 35 on to the base 25 by effectively preventing turning of the cap on the base. In addition, this pin extends through the annular space 38 and where the pin is located and constitutes a restriction in radial extent of the annular space and limits the movement of the ball bearing 40 in the raceway 38. If an attempt is made to turn the ball part 12 in either direction as indicated by the arrows 47 in Figure 5, the permissible turning is limited to an amount slightly less than 360 degrees from the dotted line position illustrated in Figure 5.

The spring 30 constantly urges the ring 32 and with it the ball 18, in an upward direction and thus creates a pressure engagement between the ball 18 and the bore in the top 35 through Which the ball extends. This pressure engagement creates enough friction between the members so that the ball 18 remains in any position to which it has been moved, while permitting adjustment of the ball against the frictional resistance.

The electric wires for extending the electric connections to the light bulb receptacle 3 are indicated at 50. Those wires extend through the support 8 and through the bore 27 in the base 25, thence through the bore 20 in the ball part 12 and through the neck 6 and into the receptacle. The receptacle may be locked against turning in the usual manner as by providing a flat 52. on the outside of the neck 15 which flat receives the end of the screw 9.

From the above description it is clear that the provision of the pin 45 which passes through the annular space 38 limits the rotation of the ball member in a direction axially of the neck 15 and thus permits unthreading of the electric bulb light receptacle when that is necessary, of course the screw 9 being first loosened.

In compliance with the requirements of the patent statutes, I have here shown and described a preferred embodiment of the present invention. It is, however, to be understood that the invention is not limited to the precise construction here shown, the same being merely illustrative of the principles of the invention.

What I consider new and desire to secure by Letters Patent is:

1. A ball and socket mechanism for an electric light receptacle, said mechanism being threaded at one end for threaded engagement with the neck of the receptacle and having a ball and socket connection between its two ends and a continuous bore therethrough from end to end for the passage of electrical conductors therethrough, the mechanism including a ball part and a socket part, the two parts having universal angular adjustment with respect to one another, yielding means maintaining the two in frictional pressure engagement whereby the two are held by friction in their adjusted positions, the ball part having a groove formed in its outer surface and the socket part having a groove formed in a surface thereof opposite the ball surface, the two grooves crossing one another, a ball bearing in both of the grooves at the crossing, one of the grooves extending through an arc of 360 degrees, and a pin extending across and intersecting the one groove and constituting a stop for the ball whereby abutment of the ball bearing with the pin limits the turning of the ball and socket joint about the center axis of said one groove to an amount less than 360 degrees, the socket part comprising two threadingly engaged pieces adapted to receive the ball end between them, said pin also extending through the two pieces of the socket part and holding them against separation.

2. A ball and socket mechanism for an electric light receptacle, said mechanism being threaded at one end for threaded engagement with the neck of the receptacle and having a ball and socket connection between its two ends and a continuous bore therethrough from end to end for the passage of electrical conductors therethrough, the mechanism including a ball part and a socket part, the two parts having universal angular adjustment with respect to one another, yielding means maintaining the two in frictional pressure engagement whereby the two are held by friction in their adjusted positions, the ball part having a groove formed in its outer surface and the socket part having a groove formed in a surface thereof opposite the ball surface, the two grooves crossing one another, a ball bearing in both of the grooves at the crossing, one of the grooves extending through an arc of 360 degrees, and a pin extending across and intersecting the one groove and constituting a stop for the ball whereby abutment of the ball bearing with the pin limits the turning of the ball and socket joint about the center axis of said one groove to an amount less than 360 degrees 3. A ball and socket mechanism comprising a ball part and a socket part, said two parts having universal angular adjustment with respect tozo-rie another, yielding means maintaining the two parts in frictional pressure engagement whereby the two are held by friction in their adjusted positions, the ball part having a groove formed in its outer surface and the socket part having a groove in a surface opposite the ball surface, the two grooves crossing one another, a ball bearing in both of said grooves at the crossing, said ball part being rotatable about the center axis of the groove in said socket part, and stopforming means located in the groove in said socket whereby abutment of the ball bearing with said means limits the rotation of the ball part about said center axis.

4. A ball and socket mechanism for an electric light receptacle, said mechanism being threaded at one end for threaded engagement with the neck of the receptacle and having a ball and socket connection between its two ends and a continuous bore therethrough from end to end for the passage of electrical conductors therethrough, the mechanism including a ball part and a socket part, the two parts having universal angular adjustment with respect to one another, yielding means maintaining the two in frictional pressure engagement whereby the two are held by friction in their adjusted positions, the ball part having a groove formed in its outer surface and the socket part having a groove formed in a surface thereof opposite the ball surface, the two grooves crossing one another, a ball bearing in both of the grooves at the crossing, one of the grooves extending through an arc of 360 degrees, and means in the one groove and constituting a stop for the ball whereby abutment of the ball bearing thereagainst limits the turning of the ball and socket joint about the center axis of said one grove.

References Cited in the file of this patent UNITED STATES PATENTS 1,166,752 Finizio Jan. 4, 1916 1,697,037 Witz Jan. 1, 1929 1,927,703 Glowacki Sept. 19, 1933 2,334,436 Pcrbal Nov. 16, 1943

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