Patent Abstract:
A unitary frame having a design simulating a magnified snowflake holds a string of lights mounted on a cord gripped in upstand channels presented by the frame between the lights on the string.

Full Description:
TECHNICAL FIELD 
     The present invention relates to decorative lighting units of the type in which a string of lights is mounted on one or more support frames to achieve a predetermined lighting design. 
     BACKGROUND OF THE INVENTION 
     In the past, wire frames have been used for holding lights on a lighting string to form an outline of an object, such as a Christmas tree. The present invention provides an improved light display system and frame for holding a light string, such that the lights present a design simulating a magnified snowflake. 
     SUMMARY OF THE INVENTION 
     In carrying out the invention, an injection-molded plastic frame is provided, having a plurality of flat spokes radiating integrally from a hub and each having several coplanar branches extending therefrom. The spokes and branches are provided with upstanding channels for receiving and holding a two-wire cord on which a series of miniature light units are mounted in series. The cord is gripped by the channels with the light units laying flat against the frame. For ease of assembly, the light units are equally spaced apart along the cord. Each branch holds a light unit and in addition a light unit is positioned between the root ends of the spokes. Multiple of the frames may be suspended or otherwise mounted in an array. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of a snowflake unit with lights in place made in accordance with the present invention; 
     FIG. 2 is a fragmentary front elevational view to an enlarged scale showing the mounting of a light unit at the top of a branch of the snowflake unit; 
     FIG. 3 is a side view of the structure shown in FIG. 2; 
     FIG. 4 is a fragmentary back elevational view of the frame of the snowflake unit; 
     FIG. 5 is a schematic of the wiring for an array of three of the snowflake units; 
     FIG. 5A is a schematic of an alternative wiring arrangement; 
     FIG. 6 is an exploded view of one of the light units; 
     FIG. 7 is a perspective view of the base of the terminal light unit with the wiring in place; and 
     FIG. 8 is a front elevational view showing the tip branch at the entry to the frame of the snowflake unit. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, it is seen that one or more snowflake units  10  are provided which are lighted by a string of light units  11 . Each snowflake unit has an injection molded, unitary backing frame  12  on which the light string is mounted. The backing frame  12  has a flat back side and each is formed with a hexagonal hub  13  with radiating spokes  14  from which a respective group of two right side branches  15   a-b , two left side branches  15   c-d , and a tip branch  15   e  extend. Each of these branches  15   a-e  has a pair of branch channels  16   a-b  about midway along their length. These branch channels  16   a-b  are complemented by an outer spoke channel  17  near the inner end of the tip branch  15   e , a central spoke channel  18  on each spoke between the root ends of the branches  15   a ,  15   c  and branches  15   b ,  15   d , and an inner spoke channel  19  between the inner branches  15   a ,  15   c  and the hub  13 . Adjacent each intersection of the hub and one of the spokes  14  a generally Y-shaped channel  20  is provided having two diverging sections  20   a ,  20   b  spacing radially outwardly slightly from the hub  13 , and having a third outwardly radiating section  20   c  projecting from the spoke. One of the tip branches  15   e  is formed with a pair of guides  21 ,  21   a  (FIG. 8) for leading in a two-wire cord  27  supplying power to the snowflake lights. 
     The light units  11  can be of the push-in type shown, for example, in U.S. Pat. Nos. 4,631,650 and 4,779,177, and 5,154,508, but having two rather than three wires in the cord. More specifically, the light units  11  may be, for example, of the type including an injection-molded two-piece plastic lampholder consisting of a socket unit  22  and a generally U-shaped base unit  23  which have a snap interfit and provide therebetween a wireway  31  for passage of a cord  27  containing an interrupted active wire  27   a  and a return wire  27   b . The socket unit  22  provides a generally circular socket cavity  22   a  along the length for receiving a push-in bulb unit  24  having an injection-molded plastic bulb holder  25  in which a bulb  26  with a pair of leads  26   a  from its filaments is mounted. Each lampholder also has a pair of elongated push-in contact elements  28  located in guideways at opposite sides of the socket cavity  22   a  and arranged to project into the wireway  31 . There the contact elements  28  pierce the insulation  27   c  of the cord  27  so as to engage the wire  27   a  of the cord on opposite sides of a respective cutout  27   d  in the wire. 
     Projecting from the socket unit  22  on opposite sides of the wireway  31  are two locking legs  32  presenting opposed locking shoulders  32   a  adjacent their outer end for interfitting with the base unit  23 . These shoulders  32   a  are adjoined by beveled lead-in faces  32   b . The inner face of each locking leg  32  is transversely concave matching the curvature of the socket cavity  22   a.    
     The base unit  23  has a pair of flexible guide fingers  34  shaped to engage the lead-in faces  32   b  and be flexed at their root end toward one another responsive to pushing of the base unit  23  and socket housing  22  together from opposite sides of the cord  27  after the base unit  23  has been positioned with the cord  27  straddled by the fingers  34  at the site of the cutout  27   d . At their root end the fingers  34  have retaining shoulders  35  between curved base flanges  36 . These shoulders  35  are engaged by the locking shoulders  32   a  when the base unit  23  and socket unit  22  are snap-fitted together over the cord  27 . As a result, the cord  27  is firmly gripped between the base unit  23  and socket unit  22 . The guide fingers are preferably arched transversely to provide each with a convex outer guide face  34   a  complementing the concave inner guide face of the respective locking leg  32 , and the free end of each guide finger  34  is preferably rounded and beveled on its convex outer side as indicated at  34   b . The base unit  23  presents a post  37  arranged between the fingers  34  to project into the cutout  27   d  in active wire  27   a  of the cord  27 . 
     The bulb holder  25  has a central socket  40  to receive the bulb  26 . This socket  40  is provided in a round plug  42  having an outwardly flared annular rim  43  spaced above its lower end, and having a relatively narrow extension  44  with opposite exterior flat side faces  44   a  between narrow pinch faces  44   b . A pair of longitudinal passages (not shown) extend through the base of the plug  42  and through the length of the extension  44  into a slot  47  located at the free end of the narrow extension and intersecting the narrow faces  44   b . These narrow faces  44   b  are spaced apart slightly less than the diameter of the socket cavity  22   a  to allow for the bulb leads  26   a  and are aligned with the bottom of positioning grooves  48  which are formed in the plug  42  and extend to an annular shoulder  49  at the base of the flared rim  43 . When the bulb  26  is positioned in the bulb holder  25 , the lead wires  26   a  extend from the bulb  26  through the passages  46  and outwardly at opposite ends of the slot  47 . Then the leads  26   a  double back over the narrow pinch faces  44   b  and part way into the grooves  48 . When the bulb unit  24  is pushed into the socket unit  22  the bulb leads  26   a  are pinched between the pinch faces  44   b  and the contact elements  28  to complete a circuit bypassing the respective cutout  27   d  in the wire  27   a.    
     The bulb holder  25  preferably is provided with a locking finger  50  which projects from the annular rim  43  and has an inturned locking element  50   a  which is tapered at its bottom side. The locking finger is arranged to spring outwardly as it rides over a sloped entry ramp  51  on the socket housing  22  when the bulb holder  25  is pushed into the cavity  22   a . Then the locking finger  50  springs inwardly at the outer end of the ramp  51  so that the locking element  50   a  engages a stop shoulder beneath the ramp. The locking finger  50  has a pair of fork arms  50   b  which connect to the rim  43  of the bulb holder  25  and are separated by an opening  50   c  which overlies the locking element  50   a . This arrangement makes it possible to injection mold the locking finger as an integral part of the bulb holder  25 . 
     The cord  27  enters the frame through the guides  21  and passes along the tip branch between its channels  16   a ,  16   b . Then it doubles back at  27   b  through the right channel  16   a  of the tip branch to enter the wireway of the first light unit  11   a . It leaves the first light unit and passes through the left channel  16   b  of the tip branch and outer channel  17  of the respective spoke  14 . Then the cord passes outward through the left channel of the outer left branch  15   d , through the wireway of the next light unit, and inward through the left channel  16   b  of the outer left branch. 
     Next, the cord passes through the central channel  18  of the spoke and outward through the right channel of the inner left branch  15   c  to the wireway of the next light unit. After passing through that wireway it returns to the spoke through the left channel of the inner left branch  15   c  to the inner channel  19  of the spoke. The cord then is guided by the Y-channel  20 ′ to pass counterclockwise through the wireway of the next light unit to commence passage to the next spoke where it passes outwardly to the light units at the outer ends of the right lateral branches  15   a - 15   b , then to the light unit on the tip branch  15   e , and then passes inwardly to the light units at the outer ends of the left lateral branches  15   d ,  15   c  to return to the inner end of the respective spokes. It will be noted that each of the three spoke channels  17 - 19  contain portions of the cord passing outwardly away from the hub and also contain portions of the cord passing inwardly toward the hub. All of the channels are sufficiently resilient to grip the portions of the cord being guided by the channels. 
     Each of the branches has a flat tip portion  12   a  located behind the respective light unit and this is normally engaged by the outer face of the respective locking finger  50  to assist in properly positioning the light unit. Preferably the tip portion  12   a  extends longitudinally outward sufficiently to act as a back guard for the bulb in the respective light unit as shown in FIG.  3 . 
     Preferably the light units are equally spaced along the cord in each frame. This simplifies production of the light strings and the mounting thereof on the frames. 
     The cord  27  is longitudinally split along the center of its insulation adjacent the terminal light unit  11   c  which is mounted on the right outer branch of the spoke at which the cord entered the frame and the interrupted active wire  27   a  is cut so that the return wire  27   b  is longer. The return wire  27   b , after passing through the wireway of the terminal light unit  11   c , is doubled back at a loop  127   d  and passed into the wireway to the end by a terminal portion  127   b  at the post  37 . Wire  27   a  ends in the wireway by a terminal portion  127   a  at the opposite side of the post as shown in FIG.  7 . These terminal portions  127   b  and  127   a  of the return wire and active wire are engaged by the contact elements  28  to complete a circuit to the bulb in the terminal light unit  11   c.    
     As indicated in FIG. 5, three, for example, of the frames may be arranged in a side-by-side array in which case the wiring circuit can include a cord for each frame with the three return wires from the frames being connected at an end connector  51  with a ground wire  52  extending from a controller  54  or a wall plug  56 , and with the three active wires extending to the controller or the wall plug. This arrangement provides a parallel-type circuit. The wires may be twisted together between clips  58  having a through passage intersected by a lateral passage as shown, for example, in U.S. Pat. No. 6,142,429. Each clip is positioned to receive the cord  27  for a respective frame into its lateral passage with its return and active wires separated by splitting the cord longitudinally and extending the resulting split portions of the cord oppositely in its through passage. When three frames  10  are used, each clip has three through wires entering and exiting from its through passage. One of these wires is the ground wire  52  from the controller  54  to the end connector  50  and the other two are through wires for the other two frames. In addition, a fourth wire appears to extend from each end of the through passage of the clip, whereas this fourth wire is actually the wires  27   a-b  in the cord  27  which extend into the through passage by way of the lateral passage in the clip and extend in opposite directions from the through passage. The clips  58  may be provided with hangers or openings to receive fasteners for mounting the clips so that the frames  10  can be suspended in generally side-by-side relation. Alternatively, the frames can be, for example, suspended one above another. 
     As indicated schematically in FIG. 5A, the return wire  27   b  need not pass through the wireways of the light units, although it is preferred that they do so in order to better grip the cord. With this modification, the return wire  27   b  extends directly from the last wire unit  11   c  to the ground of the power circuit and the cord needs to only comprise a single insulated wire. 
     From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

Technology Classification (CPC): 5