Swivel type lamp socket support

Nov. 11, 1958 f. j may 2,859,983

SWIVEL TYPE LAMP SOCKET SUPPORT Filed April 30, 1954

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INVENTOR.

Trank JasephMatj

Attir

United States Patent Office

2,859,983

Patented Nov. 11, 1958

2,859,983

SWIVEL TYPE LAMP SOCKET SUPPORT

Frank J. May, McHenry, 115., assignor to Rembrandt Lamp Corporation, Chicago, III., a corporation of Illinois

Application April 30,1954, Serial No. 426,761

Claims. (Cl. 285—90)

This invention relates to supports for lamp sockets -s or the like and particularly to an improved support which will permit rotation and swiveling of a lamp socket about laterally disposed axes.

It is an object of this invention to provide a support for a lamp socket which will permit the socket to be tilted from the vertical and also swung around in a horizontal plane, the support requiring a minimum number of parts and being rugged and durable in construction.

A more specific object of this invention is to provide a simple compound swivel support for a lamp socket wherein means are provided for preventing turning of the socket through 360° in order to prevent excessive and dangerous twisting of the cord leading to the socket, and wherein resiliently urged friction means are provided for holding a lamp socket in any of the positions permitted by the support.

These and other objects of this invention will become apparent from the following detailed description when taken together with the accompanying drawings, in which

Fig. 1 is a front elevational view of the support of this invention showing in dotted outline three inclined positions which a lamp socket supported thereby may assume;

Fig. 2 is an exploded front elevational view of the support showing the parts therefor;

Fig. 3 is an enlarged side sectional view of the support of Fig. 1;

Fig. 4 is an enlarged side elevational view, partly in section, of a sub-assembly of the support of Fig. 1; and

Fig. 5 is a plan view, partly in section, of the sub-assembly of Fig. 4, the view being taken substantially along the line 5—5 of Fig. 4.

Referring now to the drawings for a detailed description of the invention, a lamp socket support made in accordance with this invention is shown at 10 and is provided with an externally threaded end portion 11 at the upper end thereof upon which a lamp socket 12 may be mounted, as shown in dotted outline in a central vertical position A and in positions B and C, wherein it is inclined to the right and to the left, respectively, of said vertical position. The support 10 is mounted on a tubular stand, a fragment of which is shown in dotted outline at 13, the stand taking any desired overall shape or length. It is contemplated, however, that the support of this invention will be used in connection with a lamp for directing light upon written or printed material, the position of which may vary relative to stand 13, and accordingly necessitates the incorporation of sufficient flexibility in the support or the like to enable said light to be directed on such material wherever it may be located.

It is understood that the support disclosed herein will enable the lamp socket to assume any one of an indefinitely large number of positions intermediate the dotted positions A, B and C and that the same positions are available in an indefinitely large number of planes intersecting the axis of the support 10 or stand 13, with the exception of a very small angle representing the limits of rotation of the threaded tube 11 about the axis of stand 13, as will be made clear hereinafter.

The support 10 for the lamp socket 12 embodies a housing 14, a spring 15, a washer 16, a horizontally oscilδ latable ring 17 which also constitutes a part of the socket for a ball 18, a closure member 19 for housing 14 constituting also another part of the socket for ball 18, and a set screw 20 which maintains the entire support in assembled relation and also functions as a stop for rota¹⁰ tional movement of ring 17.

The several parts of the support are shown in assembled relationship in Fig. 3, in which view details of construction of each part may also be observed. Housing 14 is generally tubular and somewhat conical in form, being ⁵ larger at its top region 21, and having external threads 22 on the upper end thereof. The middle and lower regions 23 of the housing 14 are tapered so that the contour of the housing blends more pleasingly with the cylindrical con₂₀ tour of the stand 13.

The interior of housing 14 is open at the top 24, the surface of the opening being substantially cylindrical and extending substantially one-third of the distance inwardly from the upper edge of the housing. Said top opening ₂₅ 24 is connected by a shoulder 25 to an opening 26 of smaller diameter than that of opening 24, and opening 26 terminates in an inwardly extending flange 27 having a substantially radial upper surface 28 thereon facing into the opening 26. Between flange 27 and the lower end 3θ of housing 14 is an internally threaded opening 29 by which the housing 14 may be secured to the stand 13.

Closure member 19 has an internally threaded bore 30 by which it may be threaded onto the external threads 22 on the housing 14. The upper end of closure member 19 35 is flanged inwardly, the inner surface 31 of the closure member being frusto-spherical to provide a portion of the socket for ball 18. The diameter of the circle defined by the top edge 32 of surface 31 is smaller than the diameter of the circle defined by the bottom edge 33 of said 40 inner surface 31, so that ball 18, having a diameter greater than the diameter of the top edge 32, is retained in assembled relationship with respect to the support by the closure member 19.

Ball 18 has connected and substantially concentric cylin45 drical openings 34 and 35 extending therethrough for the reception of an electrical cord which connects the lamp socket through the support and stand 13 to a suitable source of electricity.: The bottom portion 36 is cut off substantially at right angles to the axis of the bores 34 50 and 35 to eliminate a sharp edge at the intersection of bore 34 with the outer surface of ball 18. Parallel flats 37 (Figs. 2 and 4) are provided on opposite sides of ball 18, said flats enabling ball 18 to extend into a slot 38 in the upper surface of the ring 17. Said slot 38 has a 55 spherical bottom surface 39 corresponding to the spherical outer surface on ball 18, and opposed parallel sides 40 adapted to engage with flats 37 to prevent the ball from turning relative to the ring 17.

It may be understood from the description thus far 60 presented that the ball 18 can rock in slot 38 in a plane parallel to the planes of the sides 40 but it cannot rock in any other direction.

Ring 17 is disposed in the top opening 24 of the housing 14 and has a peripheral groove 41 centrally disposed 65 axially of the outer surface thereof and extending through less than 360° of the periphery of said ring, so that a barrier 42 (Figs. 2, 4 and 5) is left between adjacent ends of the groove.

Ring 17 is urged against ball 18, and the latter in turn 70 is urged against the inner surface 31 of the closure member 19 by the spring 15 which is compressed between the surface 28 on the flange 27 and the pressure distributing

2.859.983 washer 16 which abuts on the lower surface of the ring 17. Washer 16 also protects ring 17 from any cutting action which might result from the turning of ring 17 on the end of spring 15. It is contemplated that the pressure exerted by spring 15 will be sufficient to effect the nec- 5 essary friction to hold ball 18 in any position to which it may be manually adjusted, but will not interpose undue resistance to adjustment of the position of the ball.

Closure member 19 holds the several parts of the support in assembled relationship. Thus, closure member 19 is threaded onto the external threads 22 on the housing 14 to substantially the position shown in Fig. 3, wherein the spring 15 is compressed to a predetermined extent to provide the desired pressure against the ring 17. To prevent an unwanted backing off of closure member 19 ¹⁵on threads 22 due to rotation of ball 18 about the axis of the support axis, the closure member 19 is secured to the housing 14 by the set screw 20 which passes through an opening 43^Jin the side of the closure member 19 and a θ threaded opening 44 in the top region 21 of housing 14 and extends into the peripheral groove 41 in the ring 17 to a position for engagement with barrier 42.

In addition to preventing relative rotation between closure member 19 and housing 14, set screw 20 performs an additional important function. It may be noted that groove 41 of ring 17 is aligned with threaded opening 44 when the support is assembled, as shown in Fig. 3. Set screw 20 has sufficient length to project into groove 40, so that when ring 17 is rotated about the axis of the ₃θ support by a corresponding rotation of ball 18, the set screw 43 will limit the rotation by contacting barrier 42 in either direction of rotation. The external diameter of the threads on set screw 20 is preferably somewhat less than the width of the groove 40, so that spring pressure _3gmay be transmitted uniformly through ring 17 to the ball 18.· Should the sides of the groove contact set screw 20, however, the spring is sufficiently flexible to cock slightly and thereby transmit its pressure to the side of ring 17 opposite the side contacted by set screw 20. Thus, al- ₄θ though the pressure upon ball 18 may be uneven, it will nevertheless be sufficient to cause the ball to be held in any selected position.

The support herein described provides a means for enabling a lamp socket to be swung through a large arc in ₄₅a horizontal plane and also through a predetermined angle in a vertical plane, thereby providing a maximum number of adjustments for a lamp socket without incurring any danger of twisting the cord for the lamp socket unduly. Any wear in the relatively moving parts of the support is 59 taken up by the spring, and hence the life of the support is at least that of the lamp as a whole. The number of parts required for the support have been reduced to a minimum and the support, when once assembled, will require no further adjustment or attention. 55

It is understood that the foregoing description is merely illustrative of a preferred embodiment of this invention and that the scope of the invention, therefore, is not to be limited thereto but is to be determined by the appended claims.