CROSS-REFERENCE TO RELATED APPLICATION 
   The present patent application claims priority on U.S. Provisional Patent Application No. 60/713,914, filed on Sep. 1, 2005, by the present applicant. 


   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to luminaire assemblies and, more particularly, to a luminaire socket of a luminaire assembly used to support light tubes in various applications, including non-exclusively transit vehicles, residential, industrial and commercial buildings. 
   2. Background Art 
   Luminaire assemblies are a well known and used type of lighting fixture. Luminaire assemblies are an efficient source of light and hence often used in large area premises, such as commercial, industrial and residential buildings. The efficient energy consumption of luminaire assemblies has resulted in luminaire assemblies being used in passenger areas of transit vehicles, such as buses, trains, subways and the like. 
   As such, luminaire assemblies must be constructed in view of conditions associated with such environments. For example, the luminaire assemblies may be subjected to constant vibrations. Accordingly, the construction of a luminaire assembly must take into account these conditions to prevent incidents, such as the disengagement of light tubes from sockets of the luminaire assemblies. Additionally, luminaire assemblies must also be constructed in view of given fire-safety and longevity standards. 
   SUMMARY OF INVENTION 
   It is therefore an aim of the present invention to provide a luminaire socket that addresses the issues of the prior art. 
   Therefore, in accordance with the present invention, there is provided a luminaire socket of the type used in spaced-apart pair to receive a light tube therebetween in a luminaire assembly, the light tube being of the type having socket caps with contact pins at opposed ends, wherein the luminaire socket comprises: a base connected to a support surface; electrical plugs within the base, the electrical plugs connected to a power source so as to provide power to a light tube; a socket connector operatively connected to the base, the socket connector having a slot for receiving therein the contact pins of a light tube in a locking position in which the contact pins of the light tube are in electrical contact with the electrical plugs for actuation of the light tube; and at least one support wall on the socket connector, the support wall being displaceable to a support position by engagement of the light tube in the luminaire socket so as to support the light tube when the light tube is accidentally disengaged from the socket connector in the locking position. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof and in which: 
       FIG. 1  is an exploded view of a luminaire socket constructed in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is a perspective view of the luminaire socket of  FIG. 1 , as assembled and in a locking orientation; 
       FIG. 3  is an elevation view of a connection face of the luminaire socket of  FIG. 1 , as assembled and in a locking orientation; 
       FIG. 4  is a cross-sectional view of the luminaire socket taken along cross-sectional line IV-IV of  FIG. 3 ; 
       FIG. 5  is a cross-sectional view of the luminaire socket taken along cross-sectional line V-V of  FIG. 3 ; 
       FIG. 6  is a perspective view of an indexing member of the luminaire socket of  FIG. 1 ; 
       FIG. 7  is an exploded view of a luminaire socket constructed in accordance with another preferred embodiment of the present invention; 
       FIG. 8  is a perspective view of the luminaire socket of  FIG. 7 , as assembled; 
       FIG. 9A  is a schematic view illustrating a light tube being directed toward the luminaire socket for interconnection therewith; 
       FIG. 9B  is a schematic view illustrating the light tube being engaged in the luminaire socket; and 
       FIG. 9C  is a schematic view illustrating the light tube being locked in the luminaire assembly. 
   


   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, and more particularly to  FIG. 1 , a luminaire socket in accordance with a preferred embodiment is generally shown at  10 . The luminaire socket  10  has a body  12  (i.e., a base), plugs  13 , a socket connector  14 , a cover  15  and a support  16 . 
   The body  12  is an interface between the various parts of the luminaire socket  10 . 
   The plugs  13  are provided for the electrical connection between the pins of a light tube and supply wires, when the light tube is locked to the luminaire socket  10 . 
   The socket connector  14  is in a preferred embodiment a rotor (hereinafter the rotor  14 ) operatively connected to the body  12 . The rotor  14  receives pins of a light tube, as will be shown hereinafter, and enables electrical contact between the light tube and the luminaire socket  10 , by its rotation with respect to the body  12 . The rotor  14  also supports the light tube as a safety feature of the luminaire socket  10 . 
   The cover  15  cooperates with the body  12  to accommodate the plugs  13  in the luminaire socket  10 . The cover  15  also indexes movement of the rotor  14  with respect to the body  12 . 
   The support  16  is the interface between the socket  10  and a support surface, such as a ceiling, a wall or a support surface with the luminaire assembly. The support  16  also biases a remainder of the socket  10  outwardly, so as to compensate for any play of a light tube between opposite sockets  10 . 
   Fasteners  17  (such as bolts, screws or the like) are provided to connect some of the parts of the luminaire socket  10 , as shown in  FIG. 2 . 
   Referring to  FIG. 1 , the body  12  has a tubular portion  20  and a casing portion  21 . The tubular portion  20  has a semi-annular surface  22  about a central opening  22 A. The surface  22  is generally smooth, as it will serve as a seat for the rotor  14 . The surface  22  is disrupted by a slot  23 . The slot  23  is provided for the insertion of the pins of a socket cap into engagement with the luminaire socket  10 . 
   A pair of eyelets  24  are provided on opposed sides of the surface  22  so as to receive the fasteners  17 , as shown in  FIG. 2 . The fasteners  17  will be screwingly engaged into the support  16 . 
   The casing portion  21  is provided to partly accommodate the plugs  13 . Connectors  25  (only one of which is visible in  FIG. 1 ) project away from the surface  22  within the tubular portion  20 . Openings  26  are provided in the casing portion  21  to access the plugs  13 . As shown in  FIG. 1 , the plugs  13  each have an arcuate central contact portion  32  with opposed connector ends  30  and  31 . 
   Accordingly, when the plugs  13  are connected to the body  12 , the connector ends  30  of the plugs  13  are lodged in the casing portion  21  in such a way that the connector ends  30  resiliently abut against a surface defining the openings  26 . 
   The connector ends  31  cooperate with the connectors  25  of the body  12 . Therefore, when the plugs  13  are secured to the body  12 , the central portion  32  of the plugs  13  protrudes into the central opening  22 A, so as to be exposed for contact with the pins of a light tube, as will be described hereinafter. 
   Live ends of wires, associated with a power source (e.g., ballast), are inserted into openings  80  so as to be releasably retained between the connector ends  30  and a surface of the openings  26 . Accordingly, contact is made between the plugs  13  and supply wires. The supply wires can be removed by the insertion of a tool (e.g., flat-head screwdriver) in the openings  26 , against the biasing action of the plugs  13 . 
   Referring to  FIGS. 1 and 6 , the rotor  14  has a pair of semi-annular walls  40 . The semi-annular walls  40  are interconnected by an indexing member  41 , and define a slot  42  therebetween. Semi-annular shoulders  43  are positioned between the walls  40  and the indexing member  41 . Support walls  44  project upwardly from the semi-annular walls  40 . As shown in  FIG. 6 , the indexing member  41  has a pair of bosses  45  for indexing an orientation of the rotor  14 . The bosses  45  are on separate legs  46 , whereby the bosses  45  can be spaced apart by temporarily bending the legs  46  away from one another. 
   Referring to  FIG. 1 , the cover  15  has a wall  50 . Wedged fingers  51  project from the wall  50 , and are provided for releasably securing the cover  15  to the body  12 , in such a way that the plugs  13  are accommodated between the body  12  and the cover  15 . 
   An indexing wheel  52  is positioned on the wall  50 . Legs  53  extend away from a center of the indexing wheel  52 . The legs  53  are separated by a slot  54 . The legs  53  each have a semi-annular flange  55  at a free end. Depressions  56  are provided on opposite sides of the wall  50 , and receive the eyelets  24  when the cover  15  is connected to the body  12 . 
   Referring concurrently to  FIGS. 1 to 6 , when the cover  15  is secured to the body  12 , the legs  53  are between the central contact portions  32  of the plugs  13  within the central opening  22 A. The rotor  14  has an underface of the semi-annular walls  40  seated upon the surface  22  of the body  12 , such that rotor  14  can rotate with respect to the body  12 . The indexing member  41  of the rotor  14  is received in the central opening  22 A of the body  12 . 
   Therefore, the rotor  14  and the cover  15  are interconnected. More specifically, the semi-annular flanges  55  of the cover  15  are received in the semi-annular shoulders  43  of the rotor  14  such that the rotor  14  is held captive to the cover  15 , while being free to rotate. However, when the rotor  14  and the cover  15  are interconnected, the indexing member  41  of the rotor  14  is operatively associated with the indexing wheel  52 . More specifically, bosses  45  are received in appropriate depressions between cogs of the indexing wheel  52 , whereby a rotation of the rotor  14  is indexed to the positions in which the bosses  45  are in the depressions. 
   Torque of sufficient magnitude causes the legs  46  to spread apart as the bosses  45  move to subsequent depressions in the indexing wheel  52 . 
   Referring to  FIG. 1 , the support  16  is a bracket  60  having a connection base  61  by which the support  16  is secured to a surface, such as a wall or a ceiling. A backwall  62  is perpendicularly mounted to the base  61 . The backwall  62  has a pair of tapped throughbores  63 , so as to receive the fasteners  17 , to secure the body  12  to the support  16 . 
   A spring wall  64  is provided on the backwall  62 . Accordingly, the spring wall  64  exerts pressure on the cover  15 . Therefore, when the fasteners  17  secure the body  12  to the support  16 , it is contemplated to provide some play such that the cover  15  is separated from the backwall  62 . In such a case, the spring wall  64  biases the assembly of the body  12 , the plugs  13 , the rotor  14  and the cover  15  against the head of the fasteners  17 . 
   Wings  65  are provided to further secure the support  16  to other parts of the luminaire. 
   Now that the various components of the luminaire socket  10  have been described, an installation of a light tube within a pair of luminaire sockets  10  is described. 
   Referring to  FIGS. 9A to 9C , light tubes A have a tubular portion B with socket caps C at opposed ends (only one of which is shown in  FIGS. 9A to 9C ) and a pair of pins D on each socket cap C. The light tube A is then secured between a pair of sockets  10 . 
   As shown in  FIG. 9A , the light tube A is directed toward the sockets  10  so as to enter the pins D of the light tube in the opposed sockets  10 . To perform this operation, the slot  42  of the rotor  14  ( FIGS. 1 to 6 ), must be aligned with the slot  23  of the body  12  and the slot  54  of the cover  15 . As shown from the exploded view of  FIG. 1 , the slots  23  and  54  are always aligned with one another. 
   Once the pins D are fully received in the central opening  22 A of the body  12 , as is illustrated in  FIG. 9B , the socket cap C is against the surface of the semi-annular walls  40 . The socket cap C is between the support walls  44  of the rotor. 
   It is pointed out that the play allowed by the spring walls  64  of the supports  16  facilitates the insertion of light tube A between sockets  10 , for instance for light tubes having a length at upper limits of tolerances. 
   Referring to  FIG. 9B , as indicated by arrow E, the light tube A is then rotated to engage the pins D against the central contact portions  32  of the plugs  13  ( FIGS. 1  to  6 ). Some torque must be manually applied to rotate the light tube A in direction E, so as to oppose against the indexing mechanism consisting of the indexing member  41  and the indexing wheel  52  ( FIGS. 1 to 6 ). 
   Therefore, clicking sounds from the indexing mechanism indicate to the user that the orientation of the light tube A within the sockets  10  is changing. It is contemplated to provide abutments in the indexing wheel  52  so as to prevent any rotation beyond 90 degrees of rotation from the initial alignment of the slots  23 ,  42  and  54  ( FIG. 9A ). In this orientation of the light tube A as illustrated in  FIG. 9C , the pins D are in contact with the central contact portion  32  of the plugs  13 , whereby the light tube A can be lit. 
   Referring to  FIG. 9C , the pins D are accommodated within the central opening  22 A of the body  12 , whereby the light tube A is held captive by the pairs of pins D at its opposed ends being within the central opening  22 A. Therefore, unless the slots  42  are in alignment with the slots  23  and  54 , unlike in the illustration of  FIGS. 2 and 3 , the light tube A is held captive between the sockets  10 . Moreover, as the indexing mechanism causes some restriction on the rotor  14 , some torque must be applied to the light tube A for the light tube A to be rotated out of engagement with the sockets  10 . 
   The support walls  44  add a level of safety, in that the support walls  44  would support the light tube A, for instance, during a breakage of the pins D. Hence, when the sockets  10  are installed, it is suggested to orient the sockets  10  such that one of the support walls  44  is vertically below the light tube A when the light tube A is in the operative position within the sockets  10  (as is shown in  FIG. 9C ). 
   The luminaire sockets in accordance with the various embodiments are advantageous, in that the safety support is deployed by the engagement of a light tube in the luminaire sockets. The luminaire socket  10  is configured so as to provide the support walls  44  upon rotational engagement of the light tube into electrical contact in the socket connector. 
   Other embodiments considered include a detent actuated by the translational engagement of the light tube into electrical contact. A spring-loaded support wall is released by the contact of the light tube on the detent. The spring-loaded support wall may then be retracted manually. The manual step required to retract the support wall (equivalent to the support walls  44  of  FIG. 1 ), in combination with the biasing of the support wall to the support configuration advantageously ensure that the light tube will be supported during use. 
   Referring to  FIGS. 7 and 8 , a luminaire socket in accordance with another preferred embodiment is generally shown  10 ′. The luminaire socket  10  of  FIGS. 1 to 6  and the luminaire assembly  10 ′ of  FIGS. 7 and 8  mostly have similar components, save for the support  16  of the luminaire assembly  10 , simply replaced by a spring wall  70 . Also, the base  12 ′ has a pair of flanged-head connectors  71 . The spring wall  70  serves a similar function as the spring wall  64  of the luminaire assembly  10 . Throughbores  72  are provided in the spring wall  70  such that the flanged-head connectors  71  may be directly received in a support surface when the luminaire socket  10 ′ is installed. 
   A variety of materials can be used to make the components of the socket  10 . For instance, it is considered to use a non-flammable plastic material for the body  12 , the rotor  14 , the cover  15  and some parts of the support  16 . The plugs  13  are typically made of a slightly flexible metal, such as brass (e.g., 4/4 brass) or beryllium. The spring wall  64  typically consists of a metal such as quenched steel. 
   It is contemplated to provide luminaire sockets  10  as described previously in different sizes and/or configurations in view of various types of tubular fluorescent lamps, such as T8 with G13 socket caps, T5 with G5 socket caps, and/or T12 with G13 socket caps. 
   Although the luminaire socket  10  is well suited for use in transit vehicles due to the presence of safety features, it is contemplated to use luminaire assemblies with luminaire sockets  10  in other applications, such as in commercial, industrial and residential buildings.
A luminaire socket is used in spaced-apart pair to receive a light tube therebetween in a luminaire assembly. The light tube has socket caps with contact pins at opposed ends. The luminaire socket comprises: a base connected to a support surface; electrical plugs within the base, the electrical plugs connected to a power source to provide power to a light tube; a socket connector operatively connected to the base, the socket connector having a slot for receiving the contact pins of a light tube in a locking position in which the contact pins of the light tube are in electrical contact with the electrical plugs for actuation of the light tube; and at least one support wall on the rotor connector, the support wall being displaceable to a support position by engagement of the light tube in the luminaire socket to support the light tube when the light tube is accidentally disengaged from the socket connector in the locking position.