Abstract:
An adapter for use with a U-section longitudinally extending power track has a base adapted to fit in the slot and a head adapted to fit outside the slot on the track so that an electrical device can be connected via the adapter to the conductors in the track. A first operating shaft extending along and pivotal about an axis in the housing carries contact fingers pivotal on rotation of the first shaft between a retracted position recessed in the base and a contacting position projecting from the base and, when the base is fitted to the slot, engaging the conductors. A second operating shaft extends along and pivotal about the axis in the housing. A second switch assembly connected to the second shaft and operable thereby on rotation of the second operating shaft to connect and disconnect the contact fingers with phase contacts on the housing.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an adapter for a power track. More particularly this invention concerns such an adapter for a multipole power track. 
       BACKGROUND OF THE INVENTION 
       [0002]    An adapter for a multipole U-section power track has a base that can be inserted into the slot of the power track and a head that sits outside the power track and to which an electrical device may be connected. A first operating shaft in the base has contact fingers for contacting electrical conductors provided in the power track and can move from a retracted position pivoted into the base to an outwardly pivoted contact position. A second switch assembly that can form a phase connection to a contact finger on phase is selectively contacted with the contact finger applied to the neutral conductor. 
         [0003]    Power tracks of this type that may be used with and are usual for such adapters are found for instance in DE-OS 22 50 738 ( FIG. 3 ). This document also shows such an adapter. 
         [0004]    In the prior art there are different types of such adapters. For instance, adapters are known in which two operating shafts are provided that are coaxially adjacent to and spaced apart from one another. A first operating shaft mechanically links the adapter to the power track and connects the neutral conductor to the power track, while the second operating shaft selects the phase so that the adapter, which is a part of the consumer, is selectively connected to one of the three phases of the power track. 
         [0005]    Other embodiments of such adapters are known, as well. Only one operating shaft is provided in these. Both the mechanical linking of the adapter to the power track and the outward pivoting of all contacts is accomplished by this one operating shaft. A slide provided with this adapter is physically adjacent the operating shaft and makes it possible to select the phases using appropriate slide positions. 
         [0006]    All of these embodiments have in common that they require relatively large amounts of space because either two parallel operating shafts must be provided in the housing of the adapter or just one operating shaft and the space for an appropriate slide for phase selection. 
       OBJECTS OF THE INVENTION 
       [0007]    It is therefore an object of the present invention to provide an improved power-track adapter. 
         [0008]    Another object is the provision of such an improved power-track adapter that overcomes the above-given disadvantages, in particular that permits a space-saving arrangement of the switching elements. 
       SUMMARY OF THE INVENTION 
       [0009]    An adapter is intended use with a U-section longitudinally extending power track having a pair of side walls defining a transversely open slot and provided on the side walls with longitudinally extending main conductors transversely exposed in the slot and connected to phase and ground. The adapter has according to the invention a housing having a base adapted to fit in the slot and a head fixed relative to the base and adapted to fit outside the slot on the track so that an electrical device can be connected via the adapter to the conductors in the track. A first operating shaft extending along and pivotal about an axis in the housing carries contact fingers pivotal on rotation of the first shaft between a retracted position recessed in the base and a contacting position projecting from the base and, when the base is fitted to the slot, engaging the conductors. A second operating shaft extends along and is pivotal about the axis in the housing. A second switch assembly connected to the second shaft and operable thereby on rotation of the second operating shaft to connect and disconnect the contact fingers with the phase contacts on the housing. 
         [0010]    This arrangement and design attains a particularly space-saving embodiment because although two operating shafts are still required, the two operating shafts are coaxial so that they connect to one another and the lateral space requirement for installing the operating shafts is minimized. 
         [0011]    The adapter functions in that when the first operating shaft is actuated all of the contact fingers are pivoted out and the adapter is also mechanically locked in the power track. By rotating the second operating shaft it is possible to select the corresponding phase to which the consumer connected to the adapter should be connected. 
         [0012]    To make manual operation easier, each operating shaft has a radially projecting, manually accessible actuating arm and may be rotated by actuating it. 
         [0013]    It is also preferable that the first operating shaft has additional mechanical latching elements that when in the retracted position are retracted into the base and in the contact position are pivoted out of the base for locking on the power track. 
         [0014]    Although such mechanical latching elements could also be provided in another manner, combining the latching elements and the first operating shaft is preferred. This ensures that once the adapter has been inserted into the appropriate power track and once the first operating shaft has been rotated, both the mechanical arresting occurs and the contacts are pivoted outward into the contact position. In addition, as is known per se in the prior art, projections or similar means may be provided on the adapter that make it possible to insert the adapter into a power track with no mistakes so that the adapter can only be inserted into the power track in one direction and not in a position rotated 180° from this direction. 
         [0015]    One particularly preferred refinement is found in that for one power track that has two other electrical conductors in addition to three phase conductors and one neutral conductor, the adapter has additional contact fingers that are pivoted inward in the retracted position and pivoted outward in the contact position. 
         [0016]    Conventional power tracks constructed like those in the above-described publication have two electrical conductors in each of the side walls of the power track, specifically two phase conductors in one side wall that are insulated and spaced apart from one another and one phase conductor and one neutral conductor in the other side wall. 
         [0017]    To increase the field of use, a new bar is proposed that has two other electrical conductors in addition to the three phase conductors and the neutral conductor. These two electrical conductors are also preferably arranged in insulating bars between the two phase conductors in the one bar side and the phase conductor and the neutral conductor in the other bar side. All of the conductors are exposed in the retaining channel of the bar so that once the adapter has been inserted the appropriate connections can be made. An additional field of use is possible since, in addition to the contact fingers that can be connected to the phase conductors and the neutral conductor, the adapter also has two other conductors that likewise have contact fingers that can pivot in and out. For instance, using the additional electrical conductors it is possible to supply another voltage source. This may be a voltage source with standard line voltage or even with low voltage. It is also possible to interpose electronic circuits or similar elements. With respect to this electric conductor, no corresponding selection of different positions is necessary; rather, in the contact position these electrical conductors are in continuous electrical contact with the corresponding contact fingers. 
         [0018]    Preferably the additional contact fingers are attached in the housing of the adapter and can be pivoted in and out by cams provided on the operating shaft by rotating the first operating shaft. 
         [0019]    The additional contact fingers are thus also pivoted out of the retracted position into the contact position by one and the same operating element, specifically by the first operating shaft, or due to inherent tension are returned from the contact position to the retracted position when the first operating shaft is correspondingly rotated into the retracted position. 
         [0020]    One particular preferred refinement is found in that the first operating shaft is rotatably held in the housing of the adapter and has an end plate, contact strips for three phase conductors and one neutral conductor exiting at the end plate of the operating shaft and forming first contact parts and on the cover opposing sides that are different distances from the end plate exiting and forming the contact fingers, and in that fixed beneath the end plate in the housing is a printed circuit board that has on its top side four first contacts for the first contact parts of the contact strips, three contacts being plated through the printed circuit board, and on the bottom side of the printed circuit board form three second contact sites and three third contact sites that act as phase connections for a consumer and that are spaced apart and insulated from the second contact sites, and in that beneath the printed circuit board, rotatably held thereto, is arranged the second operating shaft that acts as phase selection switch and has a contact bridge that in alternative rotary positions contacts a third contact site to a second contact site, and in that the fourth first contact that acts as a neutral conductor connection forms a connection site for a neutral conductor of a consumer. 
         [0021]    This arrangement makes it possible to arrange the these parts in an extremely small space and still reliably perform all functions. 
         [0022]    For the same reason the two additional electrical conductors are formed by resilient contact strips that are held in the housing and on an end area disposed in the housing form connection sites for another electrical device or an electrical control and a second end area that has contact fingers, the first operating shaft having bars or the like that act on the resilient contact strips and by means of which the contact fingers are pivoted out into the contact position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0023]    The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which: 
           [0024]      FIG. 1  is an end view of a U-section power track; 
           [0025]      FIG. 2  is perspective view an adapter that fits it, shown in the retracted position in which the contact fingers and latching elements are pivoted inward; 
           [0026]      FIG. 3  is a bottom view of the adapter shown in  FIG. 3 ; 
           [0027]      FIG. 4  is a perspective view of the adapter from below with the contact fingers moved into the contact position; 
           [0028]      FIG. 5  is a top view of the adapter as in  FIG. 4 ; 
           [0029]      FIG. 6  is a side view of the adapter; 
           [0030]      FIG. 7  is a section taken on line VII-VII of  FIG. 6 ; 
           [0031]      FIG. 8  is view of a detail of  FIG. 7 ; 
           [0032]      FIG. 9  is an exploded view of the adapter; 
           [0033]      FIG. 10  is an exploded view of a detail of the adapter; 
           [0034]      FIG. 11  is an exploded view of another detail of the adapter. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0035]    As seen in  FIG. 1  a power track  1  made of metal is essentially of U-section. Support rails  3  made of insulating material are mounted on its parallel side walls and laterally delimit a retaining channel or slot  2 . These support rails  3  each receive a plurality of uninsulated bare electrical conductors  4 - 7  that are insulated from one another, are arranged parallel to one another in the rail longitudinal direction, are opposite one another, and are exposed in the retaining channel. The conductors  4 ,  5 ,  6  may be phase conductors of a three-phase rotary current system, while the conductor  7  may be a neutral conductor for this system. Other conductors  8 ,  9 , which are insulated from and mounted between respective pairs of  4 ,  5  and  6 ,  7  of conductors, may be used for instance as control conductors for an electrical or electronic control or may be used as additional power conductors for other electrical devices. 
         [0036]    A ground conductor  10  is also provided on the floor of the power track  1 . Additionally or alternatively, a ground conductor  11  may be provided on one side wall of the power track  1 . 
         [0037]      FIGS. 2-11  show an adapter  12  that is intended for use in the power track  1 . To this end, the adapter  12  has a base  13  that may be inserted into the slot  2  of the power track  1  and a head  14  that sits outside the power track  1 . The head  14  determines the insertion depth limit for the base  13 , it being possible to provide on the power track and on the head  14  suitable elements that permit them to be relatively positioned correctly. For instance, to this end projections  53  may be provided on the head and recesses  54  may be provided asymmetrically on the power track  1 , which projections  53  and recesses  54  only permit the adapter  12  to be used in one specific position. 
         [0038]    The head  14  is suitable and intended for receiving or carrying an electrical device that may be connected electrically to the contacts of the adapter. 
         [0039]    Provided in the adapter housing is a first operating shaft  15  that can pivot contact fingers  16 ,  17 ,  18 ,  19  outward for contacting the respective electrical conductors  4 ,  5 ,  6 ,  7  provided in the power track  1  in that by rotating the first operating shaft  15  these contact fingers  16  through  19  may be moved out of a retracted or inwardly pivoted retracted position into an outwardly pivoted contact position. 
         [0040]    For instance,  FIGS. 2 and 3  show the retracted position in which the contact fingers  16  through  19  are pivoted inward.  FIGS. 4 through 6  show a position in which they are pivoted outward into the contact position. Moreover, the adapter  12  has a second switch assembly that can connect one of the phase connectors of the adapter selectively with one of the contact finger  16  through  18  that is on phase, the contact finger  19  always being on the neutral conductor contact. 
         [0041]    In accordance with the invention, the second switch assembly is formed by a second operating shaft  20 . This second operating shaft  20  is merely for phase selection and is coaxial with the first operating shaft  15  and is mounted thereon so that both may be rotated about the same axis independently of one another. 
         [0042]    Each of the operating shafts  15 ,  20  has a respective radially projecting actuating arm  21 ,  22  that can be accessed manually from outside so that the user can rotate the first operating shaft  15  by actuating the actuating arm  21 , and can rotate the second operating shaft  20  for phase selection by actuating the second actuating arm  22 . Since in the power track  1  shown in  FIG. 1  two other electrical conductors  8 ,  9  are provided in addition to the three phase conductors  4 ,  5 ,  6  and the neutral conductor  7 , the adapter  12  correspondingly also has contact fingers  23 ,  24  that are pivoted inward in a retracted position and are pivoted outward in a he contact position. In the contact position all of the actuating arms pass through window-like cut-outs in the adapter housing. 
         [0043]    The first operating shaft  15  has additional mechanical latching elements  25  that are rotationally fixed on the operating shaft  15  and in the retracted position are retracted into the base  13 , as may be seen for instance in  FIG. 2 , and in the contact position are pivoted outward out of the base  13  for locking on the power track  1 , as may be seen for instance in  FIGS. 4 and 5 . 
         [0044]    Since the contact fingers  23 ,  24  that can be connected to the additional conductors  8 ,  9  of the power track  1  are not connected to three-phase rotary current, but rather are used as a control conductor or as line-power conductor systems, it is not necessary to actuate them using the phase selector as well, that is, using the second operating shaft  20 . 
         [0045]    These additional contact fingers  23 ,  24  are attached in the housing of the adapter and may be spread by cams  26  provided on the first operating shaft  15 , as may be seen in  FIGS. 7 and 8 . If the operating shaft  15  is rotated out of the retracted position into the contact position, the contact fingers  23 ,  24  are pivoted out of the base  13  of the adapter  12  by the cams  26 . When the first operating shaft  15  is rotated back, the contact fingers  23 ,  24  return to the retracted position. 
         [0046]    As has already been described, the first operating shaft  15  is rotatably held in the housing of the adapter  12 . The first operating shaft has an end plate  27 , contact strips for the three phase conductors and the neutral conductor and that have the contact fingers  16  through  19  projecting radially from the upper part of the operating shaft, while they are guided downward to below the end plate  27  and exit there, forming first contact parts  28  through  31 . The contact fingers  16  through  19  project through the side wall of the first operating shaft  15  at different distances from the end plate  27  and on opposite sides. 
         [0047]    A printed circuit board  32  is fixed beneath the end plate  27  in the housing. On its top side this printed circuit board  32  has four first contacts  33  through  36  that, at least when the first operating shaft  15  has been rotated into the contact position, contact the first contact parts  28  through  31  of the contact strips. The first contacts  33 ,  34 ,  35  intended for phase connection are plated through the printed circuit board  32  so that they can also be contacted on the bottom side of the printed circuit board  32 . The first contact  36  is for instance the neutral conductor contact that does not have to be plated through, since it is always connected in a contacting manner to the corresponding contact finger  19  of the first operating shaft  15 . Alternatively, the other first contacts  33 ,  34 ,  35  may be contacted. The second operating shaft  20  serves this purpose. As may be seen especially from  FIG. 11 , it carries a contact bridge  37  that may be repositioned resiliently and parallel to the rotation axis of the second operating shaft  20 . Contacts provided below the printed circuit board  32  may be connected to one another by this contact bridge. These are three second contact sites that are directly connected to the first contacts  33 ,  34 , and  35 , and three third contact sites that act as phase connections for the consumer and that are spaced apart and insulated from the second contact sites. By rotating the phase selection switch, specifically the second operating shaft  20 , the contacts associated with a phase may be connected to one another by the contact bridge  37  so that then a phase is switched to the consumer. 
         [0048]    A latch element  38  may also be interposed between the second operating shaft  20  and the bottom side of the printed circuit board  32 ; it ensures that the contact bridge only latches in the three positions determined by the corresponding phases so that the user is able to precisely position the second operating shaft  20 . 
         [0049]    The two other electrical conductors that form or have the contact fingers  23 ,  24  are formed by resilient contact strips  39 ,  40  that may be seen especially in  FIG. 9 . They are held in the housing of the adapter  12  and at an end thereof in the housing have connection sites  41 ,  42  for an electrical device or an electrical control. A part  43  added to the housing of the adapter has bars  44  through  48 , that each in the retracted position protect the insertion gap or area for conductors at the connection sites  41 ,  42 , but also the other connection sites  49  on the printed circuit board and  50  on the ground conductor. 
         [0050]    The ground conductor contact  51  is also held inside the adapter housing and exits as a resilient contact  52  at the top of the adapter  12 . 
         [0051]    The inventive embodiment is thus an adapter  12  that is simple and safe to operate, that requires a small amount of space for the switching elements, and that is extremely functional, especially even when not only is a three-phase current power track  1  being used, but also a power track  1  that has two additional conductor connections in addition to three phases and the neutral conductor. 
         [0052]    The invention is not limited to the illustrated embodiment, but rather may vary widely within the context of the disclosure. 
         [0053]    All of the individual and combined features disclosed in the description and/or drawing are considered essential to the invention.