US2141879A - Electric light fixture - Google Patents

Description

Dec. 27, 1938. M. N RUSSELL ELECTRIC LIGHT FIXTURE Filed June 26, 1937 s Tn,

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m rk Njlu ssefl Patented Dec. 21, 1938 PATENT OFFICE ELEcTmc LIGHT FIXTURE Mark N. Russell, Syracuse, N. Y., assignor to Pass & Seymour, Inc., Syracuse, N. Y., a corporation of New York- Application June 26, 1937, Serial No. 150,441

7 Claims.

My invention relates to electric light fixtures and more particularly to fixtures in which the lamp-receptacle orsocket is detachably mounted upon an internal annular flange of such a supporting shell as the well-known combined ceiling-band and shade-holder of hour glass shape, internally flanged at its waist.

The construction that has long been practically standard for the above-stated type of fixture is substantially that shown in Patent No. 1,537,863 to H. J. Morey, granted May 12, 1925; that is to say, one wherein the ceiling-band shell has an internal, horizontal, uninterrupted supportingflange, and the lamp-receptacle structure to be supported thereon comprises three separable pieces; namely, a porcelain block or core carrying suitable pull-switch mechanism together with the threaded lamp-socket shell, and two complemental porcelain sleeve-members that jointly surround the core and clamp the assembly to said supporting flange; the upper sleeve member supportlvely receiving at its upper end a topenlargement of the core and at its lower end bearing on the supporting flange, while the lower 35 backs affecting their manufacture, their installation, and their maintenance of proper conditions under continued use, that I have overcome by my invention.

4 The general objects of myinvention are to imand over all other prior constructions of this general type of electric light fixture of, which I am aware, in providing more adequate and reliable clamping of the lamp-receptacle to its supporting flange; minimizing production cost of the lampreceptacle unit; facilitating the wiring and mounting of the receptacle, for reduced laborcost in installation; and attaining other advantages of which more will be said later.

To these ends my invention consists in the features of construction and combinations of parts hereinafter set forth and claimed, reference being had to the accompanying drawing wherein I have illustrated a single embodiment of my incomplemental recess in the lower edge of the up-' prove over this practically-standard construction,

vention for purposes of full disclosure, and wherein: V

Figure l is a vertical section of the assembled supporting-shell and lamp-receptacle on a diametric plane indicated by line ll of Fig. 4;

Fig. 2 is a perspective view of the receptacle unit with its parts in the positions shown in Fig. 1;

Fig. 3 is a similar perspective with clamping and shielding parts swung to open position, and with a dotted showing of an intermediate position in the course of opening;

Fig. 4 is a plan view, broken away to show some of the parts in fragmentary section on line 44 of Fig. l, with the receptacle parts in clamping position; and

Fig. 4 is a similar and complemental view showing the receptacle parts in preliminary, entering position, from which position the receptacle will be turned about its axis, as indicated by an arrow, before being clamped to the supporting-flange.

In the drawing It) indicates the supporting shell, shown as of a conventional hour-glass design, made of sheet metal, with its ceiling-band section I l and its shade-holder section l2 seamed together at the waist in usual fashion, conveniently to form the internal, horizontal, receptacle-supporting flange I3. This flange has parallel, flat upper and lower surfaces and desirably, for purposes of the preferred embodiment of my invention illustrated herein, has two diametrically opposed openings l4, notched into its inner margin, to permit easy passage therethrough of clamping parts on the lamp-receptacle hereinafter described.

. l5 indicates in general my novel lamp-receptacle, the insulating body of which provides, in I a. single-piece porcelain construction, a head-enlargement l6 and a smaller-diameter neck ll; there being a flat shoulder l8 between them to bear upon the supporting-flange l3 when the neck is slipped through the flange orifice in mounting the receptacle.

The head l6 as herein shown is designed to receive a conventional pull-switch mechanism 20 in its central chamber 2 l; accommodation for the pull-chain 22 and for the pair of wiring terminals 23, respectively, being afforded by a slot 24 and by a pair of recessed bays 25; and the neck II of the unit is cylindrically hollowed to accommodate the lamp-receiving outer contact 26 of any conventional type, not necessarily restricted to the threaded type herein shown.

To receive and cooperate with the body-carried clamping unit 33, to be later described, the head of the insulating body is shaped to provide opposed flats 21 approximately tangential to the circumference of the neck I]; a stout stop-pillar 23 is formed between the chain-slot 24 and the adjacent flat 21; and longitudinal side grooves 23 extend along the lower portions of the respective flats and into deepened extensions of such groove in the upper part of the neck IT, with the two levels of each block connected by an inclined ramp or radial clamp-camming surface 23'.

The particular clamping unit herein shown (which is also equipped for desirable functioning as an insulating cover for the switch-recess 2| and as a shield for the wiring terminals 23) comprises a pair of clamp-dogs 3| mounted on the circular end-enlargements or turning-disks 32 of the diametrically opposed, longitudinal, springy clamp-arms 33; these arms being carried by a cross-head 34 that extends diametrically over the top of the insulating block or body and which may be raised or lowered from above such body by an adjusting screw 35; such screw being threaded through the cross-head and at its lower end swivelly engaged with a plate 36 that, in turn, is arranged to flnd bearing on the it stands at an acute angle to its juncture with the corresponding end-disk 32 on which one of the clamping dogs 3| is mounted.

Thus, when the cross-head 34 of the clampdevice is lowered, the dog-carrying disks 32 of arms 33 recede into the deep end of grooves 29, in the neck portion of the unit, and in this condition the unit has its neck inserted through the orifice in the supporting flange 3 of the shell when the parts are being assembled. To preserve wall-strength of the head and neck, and a very substantial protrusion of the clamp dogs from their carrying-arms, I prefer that the dogs should protrude somewhat even under full retraction, and therefore notch the supporting flange of the ceiling-band structure, as at H, to permit the dogs to readily pass below the level of the flange; and when this partial assembly has been made the lamp-socket unit is rotated to Fig. 4 position from the position shown in Fig. 4, as indicated by the arrow on the latter figure, so as to bring the pull-chain slot 24 into proper relation to the chain-outlet opening 22' of the ceiling-band and to position both clamping dogs below solid segments of the supporting flange l3.

Turning the clamping screw 35 to raise crosshead 34 will result in flrmly and effectually clamping the flange between the dogs 3| and the shoulder I8 of the lamp-receptacle body; the flne screw thread and the direct vertical lift of the clamp insuring that the dogs 3| may bite very strongly against said flange. Additionally, the stated vertical lifting of the clamp device will ride the lower ends of its arms 33 up the ramps 23 to the position shown in Fig. 1, and the resultant cam-compelled radial movement of the disks 32 may enhance the efliciency of the clamping, by the pressing thereof against the edge of the flange.

For the additional advantage of using the clamping unit as a cover for the open end of the lamp-receptacle body, and also as an insulating shield for the wiring terminals, the plate 36 of the clamp-structure is made to cover completely the top opening of the receptacle-body, except that a small portion of the cover-plate is cut away as at 39 to accommodate the leading in of the feed-wires 41. And additionally, the cover-plate has two down-turned extensions or guards 40, positioned to overlie the respective bays 25 of the wiring terminals when said cover is closed"; the cover-plate being made nonrotatable with respect to the U-shaped clamping member by engagement of the flat arms 33 of said member against straight edge-portions 4| of the plate. A suitably contoured and molded piece of thin insulating material, 44-, is mounted securely on the underside of the cover-plate and substantially conforms to its perimeter, and suitable shield portions or tabs, 45, of said material, shaped for substantial conformity with the bays 25 for the wiring terminals, are down-bent at the margins of said head and are braced against outward displacement by the respective guards 40 of the plate.

The entire shielding and clamping device above described may be moved, however, to give free access to the switch parts and to the wiring terminals in installing or repairing the unit; the upper ends of guide-grooves 29 for the clamp arms being so located that when the circular disks 32 are fully raised (as shown in dotted lines in Fig. 3) the clamping unit assembly may be pivotally swung to the open position shown in full lines in said figure. Complete detachment of the cover-and clamp assembly may be made, but is practically never necessary.

It will be understood that the supply wires 41 for the flxture are brought through the surface to which the flxture is to be applied, with enough slack to permit of their being very readily connected to the terminals of the lamp-receptacle when the cover and locking parts of the latter are in the open position last referred to.

Thus, to install the complete fixture, the lampreceptacle unit, with its cover-and-clamping structure thrown to open position shown in full lines in-Fig. 3, first has its terminals 23 connected to the wires 41; next has its cover closed to Fig. 2 position; then is slipped into the celling-band shell, with its clamping parts in lowered position; next is turned as indicated by the arrow on Fig. 4 to align chain-slot 24 with the ceilingbands chain-outlet 22; after which the screw 35 is operated from above the receptacle to lift the clamp-structure to clamping position shown in Fig. 1, whereupon the completed assembly is ready for mounting in any convenient way in its intended position on the ceiling or wall.

It will be noted that while, by springing the arms 33 of the clamping structure completely out of the longitudinal guide grooves 23, the clamping device may be completely removed, it is, for all practical purposes of handling the receptacle, a permanently mounted part thereof and merely is slidable along and pivotable on the receptacle body; which feature, together with others heretofore mentioned, contributes to the time-saving facility of mounting the unit receptacle structure in its ornamental supporting shell.

Further it will be noted that the unitary construction of the receptacle body, ordinarily molded of porcelain, makes for low production cost; as does also the ample accessibility of the interior chambers for assembly of the electrical parts in the manufacture thereof; while the provision of the openable cover-plate and of the insulated coverage of the bays for the wiring terminals insures adequacy of the protective insulation. In this last-mentioned connection it will be seen that the insulating material underlying the metal cover-plate protrudes somewhat beyond the edges of the wire-receptive opening 39 in the latter, to further the insulating characteristics of the device; and also that the somewhat protruding pillar 28, forming one wall of the pull-chain slot, constitutes an additional insulating safeguard.

I claim:

1. An electric light fixture of ceiling-band type comprising a shell having an internal opencentered flange for positioning a lamp-receptacle, and a lamp-receptacle structure for making demountable clamping connection with said flange; said receptacle having an insulating body provided with a neck-portion adapted to be passed downwardly through the opening of said flange and an upper portion providing at its bottom a shoulder adapted to bear directly on the upper side of said flange; and clamping means carried by said body and movable axially thereof, said clamping means including a pair of clampdogs normally positioned below the flange level and adapted to engage the underside of said flange when moved upwardly, arms extending from said clamp-dogs upwardly along said body and above it, and a single manipulative means accessible from above the receptacle body operatively associated with both said arms to raise and lowerthe clamp-dogs into and out of clamping engagement with the underside of said flange. s

2. An electric light fixture of ceiling-band type comprising a shell having an internal flange apertured and oppositely notched for receiving and positioning a lamp-receptacle, and a lampreceptacle structure for making demountable clamping connection with the flange; said receptacle having a body providing a lower portion adapted to pass through the orifice of said flange and an upper portion providing a shoulder to bear directly on said flange, clamping means carried by said body and comprising a pair of diametrically opposed arms extending axially along the body from above its top to below its shoulder and having their lower ends provided with clamp-dogs adapted to pass through said notches and normally lie below the shell-flange level, said lower ends being movable both radially and axially between unclamped position and a clamped position engaging said dogs with the underside of said flange and pressing said arms radially against the edge of said flange, and means including a single manipulative device accessible from above said body operatively connected with the upper part of both said arms for simultaneously moving them.

3. An electric light fixture comprising a shell having an apertured internal flange for positioning a lamp-receptacle, and a lamp-receptacle structure for making demountable clamping connection with said flange, said receptacle having a body providing a neck portion adapted to pass through the orifice of said flange and an upper portion adapted to bear on said flange and having longitudinal grooves in opposite sides of said body extending above and below the upper portions plane of bearing on the flange, a U-shaped clamping member providing clamping dogs near the free ends of its longitudinal arms, said arms slidably engaging said grooves and having their cross-connection located above said body, means associated with said U-shaped member-for adjusting it longitudinally with respect to thebody, and camming formations in said body-grooves for forcing the ,dog-carrying ends of said arms radially outward as the dogs approach from below their position for clamping against the underside of said flange.

4. In a lamp-receptacle adaptedto be clamped to an apertured supporting flange of. a ceilingband-flxture shell, an insulating, lamp-receptive body having a laterally projecting bearing surface above its lower end and opposed longitudinal grooves along its surface extending above and below said bearing surface, a longitudinally movable clamping device having a cross-head above said body, downwardly extending springy arms guided in said longitudinal grooves and clamp dogs projecting from said arms in position normally below the bodys said bearing surface, manipulative means accessible above and bearing upon the top of said body for raising and lowering said cross-head; and camming formations in said body grooves for springing the arm-ends outwardly as the clamp-dogs approach, from below, the plane of the bodys bearing surface.

5. In a lamp-receptacle adapted to be clamped to an apertured supporting flange, an insulating, lamp-receptive body having a hollowed head carrying wiring terminals, a hollowed neck carrying lamp-socket contacts and a laterally projecting bearing shoulder between the head and neck, a combined clamping and shielding unit carried by said body and arranged for longitudinal sliding movement thereon into and out of locking engagement with the underside of a receptacle supporting flange and for bodily swinging movement to displace its upper portion laterally from shielding position, said unit including a shielding member to overlie and bear upon the top of said body, clamp-adjusting means connected with said shielding member for bodily lateral displacement therewith, and clamping means for engagement with the underside of a supporting flange and arranged to slide longitudinally and to rock laterally relative to said body, said clamping means being operatively connected to said clampadjusting means for vertical clamping adjustment thereby and to bodily displace it laterally when the upper end of said clamping means is rocked with respect to the body.

6. Structure as set forth in claim 5, wherein the head of said body has lateral openings for access to the wiring terminals, said shielding member has pendant portions to substantially cover said lateral openings and the connected assembly of clamping means, clamp-adjusting means and shielding means is longitudinally movable on the body sufiiciently to raise said guard-portions above the body before the assembly is laterally rocked.

7. In a lamp-receptacle adapted to be clamped in an apertured supporting flange, an insulating body having a neck of smaller diameter and a head of larger diameter connected by a bearing shoulder, connected pull-switch parts and terminals mounted in said head and lamp-socket contacts arranged in said neck; said body having opposed longitudinalgrooves in its outer surface extending above and below said shoulder, and a combined clamping and shielding unit carried by said body and arranged for longitudinal sliding movement in said grooves and for rocking movement when in raised position to bodily displace the upper part of said unit from normal position overlying said head, said unit comprising a. U-shaped member having a cross-head portion normally crossing above the head of. the body, longitudinal arms engaging said bodygrooves and at their lower ends carrying respective clamping dogs; a plate to bear on the top of the body's head and an adjusting screw accessible at the upper end of the structure adjustabiy connecting said cross-head and said coverplate.

MARK N. RUSSELL.

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