Patent Publication Number: US-2022239021-A1

Title: Terminal block

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of European Patent Application No. 21305104.8 filed on Jan. 27, 2021, the whole disclosure of which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present disclosure relates to electrical connectors, and more particularly, to electrical terminal blocks. 
     BACKGROUND 
     Terminal blocks may be used with a conductive bar to electrically link plugged conductors. To this end, a terminal block according to the prior art includes a plurality of plugs each having a releasable mechanism for maintaining electrical contact between each conductor and the conductive bar. The release mechanism usually comprises a retaining spring. This construction enables the constraint of the conductor within the terminal block in order to produce efficient, reliable electrical contact. Further, it is important to correctly guide the conductor during insertion such that it can be accurately placed in position relative to the retaining spring. Accordingly, an insulating casing of the terminal block may have dedicated walls, the conductive bar may have a specific form or additional accessories can be used. This is especially critical in applications used with multi-stranded conductors. Specifically, there is a need to prevent the deviation of conductor strands outside of the area between the conductive bar and the retaining spring. 
     For all of the above reasons, prior art terminal blocks can be complex, utilizing several parts. Accordingly, there is a need for an improved terminal block that is simplified in its construction, while still providing reliable performance. 
     SUMMARY 
     A terminal block according to an embodiment of the present disclosure includes an insulating casing defining a recess receiving a conductive bar and a retaining spring. The conductive bar includes a base portion, a support leg attached to the base portion, and a cooperating leg attached to the base portion. In a mounted position of the conductive bar and the retaining spring within the recess, the support leg engages with a support part of the retaining spring, and the cooperating leg is positioned to engage with a conductor inserted into a plug of the terminal block. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is a perspective view of a terminal block with a conductive bar and a retaining spring in a mounted position; 
         FIG. 2  is a perspective view of an insulating body of the terminal block; 
         FIG. 3  is a perspective view of the conductive bar and the retaining spring; and 
         FIG. 4  is a perspective view of the conductive bar. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art. 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
     As illustrated in  FIGS. 1-4 , a terminal block  1  comprises an insulating casing  3 , a conductive bar  5  and a retaining spring  7 . The insulating casing  3  extends according to a main plane  9  and defines a lateral recess  11  sized for an insertion of the conductive bar  5  and the retaining spring  7  transversally to the main plane  9  into a mounted position. 
     The conductive bar  5  (see  FIGS. 3 and 4 ) presents in mounted position a base portion  13  extending according to a middle plane  15  transverse to the main plane  9  and a lateral portion  17  attached to the base portion  13  and extending parallel to the main plane  9 . The conductive bar  5  further comprises a support leg  19  attached to the base portion  13  and configured to cooperate with a support part  21  of the retaining spring  7 . A cooperating leg  23  of the conductive bar  5  is attached to the base portion  13  and configured to cooperate with a conductor  25  inserted in a plug  27  of the terminal block  1  when the conductor  25  is maintained or fixedly held by the retaining spring  7 . The support leg  19  and the cooperating leg  23  are oriented transverse to the middle plane  15  and extend in opposite directions transversally to the middle plane  15 . The lateral portion  17  and the cooperating leg  23  extend in the same direction transversally to the middle plane  15 . In this way, the support leg  19 , the cooperating leg  23  and the lateral portion  17  are each attached to the base portion  13  and extend transversally with respect to the base portion  13 . The support leg  19  extends from the base portion  13  in a direction, and both the cooperating leg  23  and the lateral portion  17  extend from the base portion  13  in an opposite direction. 
     As illustrated in  FIG. 2 , the lateral recess  11  of the insulating casing  3  defines a bottom surface  29 . The retaining spring  7 , the support leg  19  and the cooperating leg  23  are located between the bottom surface  29  and the lateral portion  17  transverse to the main plane  9 . When inserted, the conductor  25  is located between the lateral portion  17  and the bottom surface  29  transverse to the main plane  9 . The conductor  25  is then guided on one side by the conductive bar  5  and on the other side by the insulating casing  3 . The conductive bar  5  defines an L-shaped profile constituted by the base portion  13  and the lateral portion  17 . 
     The plug  27  has an inserting hole  31  made in the insulating casing  3 . The inserting hole  31  extends transversally to the middle plane  15  and opens on the lateral recess  11 . During insertion, the conductor  25  is maintained transversally to the main plane  9  by the insulating casing  3  on both sides in the inserting hole  31  and on one side by the lateral portion  17  and on the other side by the bottom surface  31  in the lateral recess  11 . 
     As illustrated in  FIG. 3 , the retaining spring  7  is a leaf spring provided with two strips  33  that are symmetrical with respect to a central plane  35  of the retaining spring without any constraints applied on the retaining spring. In mounted the position, the central plane  35  is transverse to the main plane  9  and to the middle plane  15 . In addition, the central plane  35  is inclined with respect to the inserting hole  31 . More particularly, the central plane  35  is perpendicular to the main plane  9  and inclined with respect to the middle plane  15 , the inclination being greater than 45°. 
     Referring again to  FIGS. 1 and 2 , the insulating casing  3  defines actuating orifice  37  therethrough. The actuating orifice  37  extends transversally to the middle plane  15  and opens on the lateral recess  11 . The actuating orifice  37  is oriented toward a movable part  39  of the retaining spring  7 . The actuating orifice  37  is configured to enable a tool, such as a screwdriver  41 , to displace the moving part  39 . The moving part  39  is configured to exert a constraint on the conductor  25  in the absence of actuation to maintain the conductor  25  in electric contact with the cooperating leg  23 . 
     Each strip  33  of the retaining spring  7  extends in a corresponding direction and defines two undulations. A first undulation  43  is opposed to the central plane  35  and designed to be in front of the actuating orifice  37 . A second undulation  45  extends toward the central plane  35  to orient an ending part  47  of the retaining spring  7  in an inclined position with respect to the central plane  35 . 
     The lateral recess  11  is defined by a lateral blind slot in the thickness  49  of the terminal block  1 . The lateral recess  11  comprises an insert for receiving the retaining spring  7  and the conductive bar  5  within the thickness  49  of the terminal block  1 . The thickness  49  of the terminal block  1  is defined as being the dimension of the terminal block  1  transversally to the main plane  9 . The conductive bar  5  and the retaining spring  7  are contained within the thickness dimension of the terminal block  1 . 
     The support leg  19  and the cooperating leg  23  are folded cut-outs of the conductive bar  5 . The folded cut-outs form a passage  51  through the base portion  13  transversally to the middle plane  15 . The support leg  19  has a lower blocking element  53  arranged to cooperate with a support extremity  55  of the retaining spring  7  to prevent the displacement of the support extremity  55  in a lower direction  57  opposed to the base portion  13  transverse to the middle plane  15 . 
     The lower blocking element  53  defines a fixed place for the support extremity  55  of the retaining spring  7 . During the insertion of the conductor  25  in the plug  27 , the support extremity  55  stays in place transversally to the middle plane  15 . The lower blocking element  53  is a placement corner engendered by a bend made in the support leg  19 . 
     The cooperating leg  23  has a higher or upper blocking element  59  arranged to cooperate with a cooperating extremity  61  of the retaining spring  7  to prevent the displacement of the cooperating extremity in a higher or upward vertical direction  63  opposed to the base portion  13  transverse to the middle plane  15 . The higher blocking element  59  defines a fixed location for the cooperating extremity  61  of the retaining spring  7 . In the absence of the conductor  25  in the plug  27 , the cooperating extremity  61  stays in place transversally to the middle plane  15 . This means that, in the absence of the conductor  25 , the support extremity  55  and the cooperating extremity  61  are maintained in place transverse to the middle plane  15 . The higher blocking element  59  is a placement corner engendered by a bending made in the cooperating leg  23 . 
     The cooperating leg  23  comprises a tilted end  65  and a linking part  67  that connects the tilted end to the base portion  13 . The tilted end  65  and the linking part  67  engender a cooperating protrusion  69  for cooperating with the conductor  25 . The higher blocking element  59  is located on the linking part  67 . 
     According to an embodiment of the present disclosure, the conductive bar  5  is formed by a conductive sheet plate that is folded about a main axis  71  to form the lateral portion  17  and the base portion  13 . The support leg  19  and the cooperating leg  23  are folded with respect to two parallel axes  73  that are transverse to the main axis  71 . 
     The conductive sheet plate defines an overall rectangular form, with the lateral portion  17  being a side strip and the base portion  13 , support leg  19  and cooperating leg  23  constituting the other strip. The support leg  19  and the cooperating leg  23  are contiguous parts of the other strip. Thus, the folding of the support leg  19  and of the cooperating leg  23  engender the passage  51  through the base portion  13  transverse to the middle plane  15 . The side strip presents at least a groove  75  along its length which confers rigidity to the lateral portion  17 . 
     The terminal block  1  comprises a clipping system  77  for installing conductive bar  5  in mounted position. The conductive bar  5  comprises a first part of the clipping system  77  and the insulating casing  3  comprises a second part of the clipping system  77 . 
     The construction of the terminal block  1  laterally maintains the plugged conductor(s)  25  and also to exerts a maintaining force on the conductor(s)  25  in proximity to a junction between the base portion  13  and the lateral portion  17  with the retaining spring  7 . This facilitates the insertion and the positioning of the conductor(s)  25  in the plug(s)  27  of the terminal block  1 . This geometry is especially efficient when a multi-stranded conductor  25  is used but is also suitable for rigid push-in conductors  25 . With a multi-stranded conductor  25 , embodiments described herein improve the quality of the electrical contact as there is a limited risk of strand deviations during insertion of the conductor. Further, the plugged conductor  25  is guided and maintained laterally with a conductive bar  5  constituted by a limited amount of conductive material. The construction of the conductive bar  5  is simple as there are a few folding steps, while maintaining suitable rigidity. 
     In addition to the above, those areas in which it is believed that those of ordinary skill in the art are familiar, have not been described herein in order not to unnecessarily obscure the invention described. Accordingly, it should be understood that the invention is not to be limited by the specific illustrative embodiments, but only by the scope of the appended claims. 
     It should be appreciated for those skilled in this art that the above embodiments are intended to be illustrated, and not restrictive. For example, many modifications may be made to the above embodiments by those skilled in this art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration or principle. 
     Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents. 
     As used herein, an element recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of the elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.