US2567291A - Electric lighting fixture with rotatable base and rotatable housing - Google Patents

Description

Sept..1 1, 1951 o. L DQUIST 2,567,291 ELECTRIC LIGHTING TURE WITH ROTATABLE BASE AND ROTATABLE HOUSING Filed Jan. 22, 1949 2 Sheets-Sheet 1 IN VEN TOR. OLIVG'RZ- l ww Q at: 7-

.4 TTORNE'Y p 11, 1951 o. L. LUNDQUIST 2,567,291 ELECTRIC LIGHTING FIXTURE WITH ROTATABLE BASE AND ROTATABLE HOUSING Fi led Jan. 22, 1949 2 Sheets-Sheet 2 44 r INVENTOR.

OlfvIERLnuNj Q 013 T A TTORNE) a standard ceiling outlet box 30, or the like, in such fashion that the spinning can turn about its axis of symmetry, in this instance, a vertically disposed axis. Said means comprises a grommet 32 whose lower headed end is seated on the under surface of, the middle section of the spinning. The shank of the grommet extends through the central aperture of said middle section, through a central aperture 33 in a strap 34 spanning the open side of the ceiling plate and through a central aperture 35 in a compression-spring-type washer 36. The upper headed end of the grommet rests on the upper surface of said washer. By way of example, said washer includes sloped and flaring resilient fingers 38 which strongly bias the strap into frictional engagement with the spinning 18. The spinning, strap and spring function as a springloaded rotatable friction joint which permits ro-. tation of the spinning relative to the strap about an axis coincident with the axis of symmetry of the spinning. By clinching the grommet to a proper extent, i. e., by reducing the distance between the heads of the grommet when heading one or both ends thereof in a conventional eyelet heading machine, an appropriate degree of frictional restraint against rotation will be imposed.

The spinning, strap and spring constitute a pre-assembled unit 39. Said unit is mounted on the ceiling box by screws 40 which pass freely through openings 42 in the strap and threadedly engage tapped lugs 44 integral with and extending inwardly from the walls of the ceiling box.

Access to said screws is had through diametrically p opposed over-sized openings 46 in the bottom wall 24 of the spinning.

Inorder to supply electrical energy to the fixture, and more particularly to the electric lamp L contained therein, an electric cable 48 is provided. Said cable runs through the grommet 32 and a grommet-protected opening 50 in the dished section 26 of the spinning. Due to this arrangement, the cable will twist when the spining is rotated. Should the spinning be rotated several turns in the same direction, the cable may be mutilated or even broken. To prevent this, the unit 39 includes means for limiting rotation of the strap and spinning to slightly less than one turn. Said means comprises 2. lug 52 struck from the strap 34 and lying in the circular path of travel of a tine 54 which extends integrally from the spinning I8 and sweeps across the undersurface of the strap.

The stem [6 has an upper threaded end protruding through an opening 56 in the bottom wall of the spinning, being radially offset from the center thereof. This end is held fast to the spinning by a pair of nuts 58, 60 which, after being tightened in place, are rigidly and permanently secured to the stem as by sweating the same with solder.

The unit 39, with the exception of the flange 22, is covered by a canopy 60. Said canopy has a tubular side wall 62 in which the tubular wall 20 of the spinning is telescopically received. The bottom wall 64 of the canopy is domed and provided with an aperture 66 to pass the stem 16. Said canopy is secured to the unit 39 in some suitable manner, for example by tiny screws 68 freely passing through openings in the tubular wall 62 of the canopy and threaded into tapped holes in the spinning.

It will be appreciated that due to the foregoing arrangement, the canopy 60' and stem 16 can be turned together about the axis of symmetry of the concealed spinning and grommet. It also will be seen that the junction between the base and stem is completely free of any external connecting elements so that this portion of the fixture presents a clean appearance.

The shell housing l4 may be fabricated from sheet metal, for example, drawn from sheet aluminum. Such housing includes a socket holding portion in which has the external configuration of a truncated cone whose narrow end is closed. Integral; with the open, wide end of this portion i0 is a lamp holding portion 12 which, as illustrated, is roughly in the shape of a parabolic reflector although not intended to function as such. The portion 12 is sufiiciently large to house any one of a plurality of diiferently sized lamps some of which are indicated by dot-and-dash lines in Fig. 1. These lamps all include built-in reflectors and are of both the spot and fiood types. It may be mentioned that the particular configuration of the housing is not part of the instant invention.

The stem [6 has an angularly offset lower end 74 whose tip is threaded and passes through an opening '56 in the housing portion 12. This threaded tip has a bolt 18 screwed thereon and fixed held in place as by sweating with solder. The threaded tip also extends through an opening in a bracket which rests against said bolt 78 and is free to turn with respect to the stem. The bracket is forced into frictional surface contact with the bolt by a compression-spring-type washer 82 through whose apertured base the threaded tip protrudes to receive a nut 84.

The nut 84 is tightened on the stem sufficiently to impart the proper degree of frictional restraint to rotation of the bracket 80 relative to the nut 18. Thereafter said nut is fixed to the stem in any suitable manner, for example, by sweating with solder. The angularly offset portion of the stem, the two nuts, the bracket and the spring 82 function as a spring-loaded rotatable friction joint which permits rotation of the bracket relative to the stem about the longitudinal axis of the angularly offset portion of said stem. Since this joint is within the shell housing it is concealed from view and permits the rotatable connection between the stem and housing to present an externally clean appearance.

The bracket 80 has a leg 86 running down inside the wall of the socket holding portion 1a of the shell. Against this leg is juxtaposed a leg 88 of a second bracket 90 having its other leg 92 secured to the base of a porcelain socket 94 for the lamp L. The two legs 86, 38 are fixed to the housing by screws as having their heads externally disposed and their shankspassing freely through openings 98 in the leg 86 and threaded into tapped holes I00 in the leg 88.

It may be mentioned here that the use of two brackets 86, 90, such as shown and described, expedites placement of the socket 94 in its housing portion 10 and assembly of the various components of the rotatable spring-loaded joint connecting the housing l4 to the stem, since the socket must be introduced into the housing portion 10 in a direction substantially parallel to the axis of symmetry of said portion while the bracket 80 must be seated on the angularly ofiset portion of the stem in a direction generally parallel to the longitudinal axis of this portion.

The electric cable 48 runs from the lowerend of the stem to the socket where it is aifixed; hence it is not desirable to permit the shell housing to tubular element and hollow members, tubular element, and spring washer constitute a spring-loaded rotary friction joint, means to interconnect one end of said stem and said second member at a region on said second member spaced from the axis of rotation of said members, said interconnecting means beinghollow, an electric cable extending through said interconnecting means into said hollow stem, means to limit the relative rotation of said members to less than a full turn, a canopy superimposed over and coveringsaid members and having an opening through whichsaid stem passes, and means to connect said canopy to said second member for movement therewith.

. 4. An electric lighting fixture of the character described comprising a base, a hollow stem and a lamp h'ousing carried by said stem; said base including a mounting plate adapted to be detachably secured to an outlet box, said plate having an opening therein, a member disposed adjacent saidplate, said member having an opening therein in registry with the opening in said plate, a tubular element extending through said openings to rotatably interconnect said plate and member, a spring washer encircling said tubular element and held under compression to urge said member and plate together whereby said member plate, tubular element and spring washer constitute a spring-loaded rotary friction joint, a

second opening in said member radially ofiset from the first opening therein and end of said stem extending through said second opening, means to secure said stem to said member, a third opening in said member, an electric cable extending through said hollow element and said third opening into said hollow stem, means to limit rotation of said plate and member to less than a full turn, a canopy superimposed over and covering said member and having an opening through which the stem passes, and means to, connect said canopy to said second member for movement therewith. 7

5. An electric lighting fixture of the character described comprising a base, a hollow stem having' one end connected to said base, and a lamp housing; said stem having its ends disposed at an angle relative to one another; said housing having an opening through which the other end of the stem extends into the housing, an element in the housing, means to connect said element to the housing for movement therewith, said element having an opening through which the end of the stem in the housing extends, a second element in the housing, means to connect said second element to the stem for movement therewith, a

spring to urge said elements together whereby said two elements and spring constitute a springloaded rotary friction joint, a socket in said housing, means to connect said socket to said housing for movement therewith, an electric'cable running from said stem to said socket, and means to limit the relative rotation of said elements to less than a full turn.

6. An electric lighting fixture of the character described comprising a base, a hollow stem and a lamp housing; said base including a stationary member, a second member in juxtaposition to said stationary member, a rotary friction joint interconnecting said members, means to interconnect one end of'said stem and said second member at a region on said second member spaced from the axis of rotation of said members, said interconnecting means being hollow, an electric cable extending through said hollow interconnecting means and into said hollow stem, acanopy superimposed over and covering said members and having an opening through which said stem passes, and means to connect said canopy to said second member for movement therewith; said stem having its ends disposed at an angle relative to one another; said housin having an opening through which the, other end of the stem extends into the housing, an element in the housing, means to connect said element to th housing for movement therewith, said element having an opening through which the end of the stem in the housing extends, a second element in the housing, means to connect said second element to the stem for movement therewith, a rotary friction joint interconnecting said elements, the axis of rotation of said joint being transverse to the axis of rotation of the first-named joint, a socket in said housing, and means to connect said socket to said housing for movement therewith, said cable running from said stem to said socket.

7. An electric lighting fixture of the character described comprising a base, a hollow stem and a lamp housing carried by said stem; said base including a stationary member, a second member in juxtaposition to said stationary member, a rotary friction joint interconnecting said members, means to interconnect one end of said stem and said second member at a region on said second member spaced from the axis of rotation of said members, said interconnecting means being hollow, an electric cable extendin through said hollow interconnecting means and into said hollow stem, a canopy superimposed over and covering said members and having an opening through which said stem passes, and means to connect said canopy to said second member for movement therewith.

OLIVER L. LUNDQUIST.'

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number

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