Abstract:
A light strip power block is disclosed which includes a base, a cover for the base having an opening formed therein for receiving an electrical power supply cable of the type having an outer protective sheathing and at least two interior power leads. The cable is secured to the base in a fixed position against movement relative to the base and a terminal block mounted on the base which includes a first pair of adjacent electrical contacts for respectively receiving the power leads of the power supply cable and a second pair of adjacent electrical contacts opposite to and electrically connected with the first pair for respectively receiving the electrical contact leads of a light strip whereby power is supplied from the cable to the light strip.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to power supply modules and particularly power supply modules for use with strip lighting fixtures. 
     2. Description of the Related Art 
     Strip lighting fixtures used to illuminate the interior of furniture pieces or to provide decorative and accent lighting are known in the art. These types of fixtures are typically formed from an elongated track of insulating material which is formed in a flat strip and contains a series of electrical connections or clips for mounting cylindrical glass bulbs. The flat strip includes a pair of electrical contact leads along its opposite edges which connect alternately with the bulb clips to provide current to the bulb. Strip lighting fixtures of this type are shown for example in U.S. Pat. No. 4,979,081. While such fixtures have been found to be highly desirable in use, connecting the contact leads of the strips to conventional electrical supply boxes, is often awkward or unpleasing in appearance. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide power supply blocks for strip lighting fixtures of the type shown in U.S. Pat. No. 4,979,081 which are relatively simple in construction and pleasing in appearance. 
     Another object of the present invention is to provide a power supply block which allows for quick interconnection of the light strip to the block. 
     Yet another object of the present invention is to provide a quick, reliable and inexpensive structure for connecting light strips to electrical power supplies. 
     In accordance with an aspect of the present invention, power supply blocks which are suitable for connecting light strips to a current source either from Romex or BX cable are provided. The basic power block consists of a metal base and a plastic cover for the base. The cover has one or more openings formed therein for receiving an electrical power supply cable having an outer protective sheathing and at least two power leads. The cable can be a conventional Romex or BX cable. The block contains means for securing the power supply cable to the base in a fixed position against movement relative to the base. A terminal block is mounted on the base and has a first pair of adjacent electrical contacts for respectively receiving the power supply leads of the power supply cable. The terminal block further includes a second pair of adjacent electrical contacts opposite to and electrically connected with the first pair for respectively receiving the electrical contact leads of a light strip whereby power is supplied from the cable to the light strip. 
     In the Romex form of the invention, a clamp arrangement is provided as the means for securing the power supply cable to the base. The clamp arrangement includes a cable block mounted on the base and a clamping bar threaded down on the block to capture the Romex cable in a channel formed in the cable block. In the BX form of the cable the base has one or more pry-out openings formed therein so that the BX cable can enter the block through the opening and be secured to the base by conventional BX cable locking arrangements. 
     The above, and other objects, features and advantages of the invention will be apparent in the following detailed description of illustrative embodiments thereof, which is be read in connection with the accompanying drawings wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a light strip power supply block connected to a light strip in accordance with the present invention; 
     FIG. 2 is an exploded perspective view of FIG. 1; 
     FIG. 3 is a sectional view taken along line  3 — 3  of FIG. 1; 
     FIG. 4 is a sectional view taken along line  4 — 4  of FIG. 4; 
     FIG. 5 is a perspective view of another embodiment of the present invention; 
     FIG. 6 is an exploded perspective view of the embodiment of FIG. 5; 
     FIG. 7 is a sectional view taken along line  7 — 7  of FIG. 5; and 
     FIG. 8 is a perspective view taken along line  8 — 8  of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings in detail and initially to FIG. 1, a light strip power block  10  constructed in accordance with one embodiment of the invention is disclosed connected to a light strip  12 . The light strip  12  is constructed in any convenient and known manner, such as for example as is disclosed in U.S. Pat. No. 4,979,081. The strip consists of a flexible strip or base  14  having positive and negative current supply leads  16 ,  18  formed in its opposite edges. The strip provides a support for a series of connector elements or clips  20  which are connected to one or the other of the power leads  16 ,  18 . The clips support cylindrical incandescent bulbs  22  or the like in the known manner. When power is supplied to leads  16 ,  18 , the bulbs are illuminated. 
     Power supply block  10 , as described in detail hereinafter, allows for quick and simple plug-in type connection and assembly of the light strip to the block. The block is in turn connected to a power supply cable such as, for example, a strip of Romex cable  24  as illustrated in FIGS. 1-4. 
     Referring to FIGS. 2-3, power block  10  includes a base  26  formed of metal or the like. A power supply cable clamp  28  is mounted on base  26  adjacent to a terminal block  30 . A cover  32  is provided to cover and insulate the assembly. Cover  32  has a front opening  34  and a rear opening  36  formed therein to allow access to the interior of the block by the Romex cable and/or power supply strip  12 . 
     Clamp means  28  consists of an insulated block of material  38  which, as seen in FIG. 2, has a channel  40  formed between its sides  42 ,  44 . Romex cable  24  fits in this channel, as seen in FIG.  3 . It is held in place by a clamp bar  45  which extends across channel  40 , as seen in FIG.  4  and has an integral cable pad  46  formed thereon. Pad  46  depends from bar  45  and engages the top of the Romex cable. When the bar is screwed into place by the screws  48  which enter the block  38 , a clamping force is applied to the Romex cable. 
     Block  38  is secured to the base  26  in any convenient manner, as for example, by rivets  52  extending through the bottom of the base and into the bores  50  formed in the sides of block  38 . 
     As is well known in the art, Romex cable contains 2 or more power leads  52 ,  54  in a plastic or rubber sheath. The ends of the leads  52 ′,  54 ′ are stripped to expose the metal leads in order to make electrical contact. In accordance with the present invention, a terminal block  56  is provided to which the leads are connected. The leads  16 ,  18  of the power strip also enter the same terminal block  56  to make an electrical connection with the power supply cable. 
     Terminal block  56  is itself of conventional construction. It contains a pair of through passages  58  formed of an electrically insulating material each of which contains within it a metal sleeve  60 . These sleeves contain inverted U-shaped spring elements  62  which are respectively engaged by set screws  64 . The U-shaped spring member provides a resilient contact for receiving either the wire leads  52 ′,  54 ′ or the light strip leads  16 ,  18 . As will be understood by those skilled in the art, the leads are simply placed in the openings  68  defined by the conventional channel members until they engage the vertical surfaces of the U strip  62  as seen in FIG. 3, at which point the set screws  64  are tightened to firmly clamp the power leads within the terminal block. 
     Each terminal block is provided with a terminal cap  70  which aids in securing the terminal block to the base in order to hold it firmly in place against movement. The cap is also formed of a thermo plastic or plastic electrically insulating material. It has a top surface  72  and side walls  74 . The inner surface  76  of the cap is generally complementary in shape to the surface of the terminal block. The cap has four openings  78  formed in it which receive the collars  80  of the terminal block in which set screws  64  are located. The side walls have lower edges  82  which rest on the surface of the base  16  and have edge extensions  84  which lie along the sides of the base. A rivet, similar to the rivets  52  previously discussed is inserted through base  26  and the central opening  86  of the terminal block into the cap  72 , thereby to secure the cap and terminal block to the base. The side edges of the cap prevent the terminal block from twisting about the base. As a result, the terminal block stays securely aligned with the opening  34  in cover  32  so that the light strip is easily mated to the terminal block to accept power from the Romex cable. 
     Finally, cover  32  is secured in place on the base by a screw  90  which threadedly engages a boss  92  formed on the top surface of the cap. As a result of this construction a relatively simple terminal block is provided which insures positive connection to the light strip. The terminal block is easily assembled by the electrician and firmly clamps the Romex cable in place against movement. 
     FIGS. 5-8 illustrate a form of the invention used with BX cable  100 . As is well known in the art, BX cable is a metal sheath or clad cable which contains electrical power leads  102 ,  104  therein. In this embodiment of the invention the power block  110  includes a cover  112  and an L-shaped based member  114 . As seen in FIG. 6, the L-shaped member  114  has one or more pry-out disk  116  formed therein. The pry-out disk  116  in the horizontal leg shown in FIG. 6 is illustrated in place while the pry-out disk in the vertical leg has been removed from the vertical leg and is shown in phantom lines. 
     By prying out one of the disks, as illustrated in FIGS. 6 and 7, the BX cable can be passed through the opening formed by the removed disk and clamped in place to the base using conventional BX cable clamping technology. For example, a circular washer  120  having a threaded neck  122  can be provided which slips over the end of the BX cable  104  in the known manner. The lock washer is fixed on the BX cable by a set screw  122  or the like. A nut  124  is provided within the interior of the power block to thread on the neck of the lock washer and draw the clamp against the upright wall of base  114  to clamp the BX cable in place. Alternative forms of BX cable clamps, including two-piece clamp members with an integral threaded neck would be suitable for use as well and would be understood by, those skilled in the art. 
     In this embodiment of the invention a terminal block and cap identical to that previously described with respect to the embodiment of FIGS. 1-4 are mounted on the base  114  in line with the opening formed by the pry-out disk to receive the ends  52 ′,  54 ′ of the power supply cable as previously described. Here the terminal block has the same structure as that described above with respect to FIGS. 3 and 4 and the description thereof need not be repeated. However, it is again noted that the cap on the terminal block is designed to be complementary to the shape of the terminal block and its bottom edges lie along the edges of the base  112  to prevent twisting of the terminal block in the power block. As in the prior embodiment, the cover  112  is secured to the base by a screw  90  which threads into a boss  92  formed in the terminal block cap. 
     As will be understood by those skilled in the art, this structure for the power block is relatively simple in construction, but is reliable in use and quick to operate. 
     Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be affected therein by those skilled in the art without departing from the scope or spirit of this invention.