Patent Publication Number: US-7896710-B2

Title: Electrical contact device

Description:
PRIORITY STATEMENT 
     The present application hereby claims priority under 35 U.S.C. §119 on German patent application number DE 10 2009 030 917.9 filed Jun. 25, 2009, the entire contents of which are hereby incorporated herein by reference. 
     FIELD 
     At least one embodiment of the invention generally relates to an electrical contact device for an arrangement having two apparatuses, between which a relative movement takes place along a first movement path, having a first contact, which has a first contact surface, and having a second contact, which has a first multiplicity of contact arms, which are each provided with a contact projection for making contact with the first contact surface. 
     BACKGROUND 
     Patent specification DE 195 19 786 C2 discloses an electrical contact device which has a flat-plug connection device with a plurality of first contacts in the form of flat-plug connections, and a socket connection device with a plurality of second contacts in the form of connections which are provided with self-supporting contact arms. In this case, each of these two connection devices is fitted in a fixed position to a respective apparatus. The two apparatuses can be fitted to one another by movement in a movement direction, wherein an electrical connection is made between the contacts at the same time when the two apparatuses are fitted to one another, and is maintained over a large movement distance of the relative movement of the two apparatuses. 
     In order to avoid excessive wear along a specific line on the flat-plug connections during this process, provision is made for the contact projections of mutually adjacent contact arms to be offset with respect to one another in a direction which runs transversely with respect to the movement direction, such that they slide along different points over the contact surface of the first contact associated with them. 
     SUMMARY 
     At least one embodiment of the invention is based on preventing excessive friction wear to the first contacts even when the contact projections of the associated second contact are arranged successively in the same direction as the first movement path. 
     In at least one embodiment, according to the invention, a device is provided for controlling a relative movement between the two contacts along a second movement path, which runs parallel to the contact surface of the first contact and obliquely with respect to the first movement path. 
     Preferred developments of the invention are specified in the dependent claims. 
     In at least one embodiment, the device for controlling the relative movement can therefore advantageously comprise a wedge control, by which the first contact and/or the second contact can be moved parallel to the first contact surface and obliquely with respect to the first movement path, or can be pivoted about a shaft which runs transversely with respect to the first contact surface. 
     In addition, the device for controlling the relative movement may comprise a return apparatus having a spring force which counteracts the wedge control or a positive guide which positively guides the relative movement between the two contacts along the second movement path. 
     Preferably, the first movement path with respect to which the contact projections are arranged successively in the same direction extends in a straight line in a movement direction. 
     A large movement distance of the relative movement of the apparatuses to be provided with the contacts can be taken into account in that during the relative movement of the two contacts, in an entry position and in a final position as well as in all the positions which can be assumed between the entry position and the final position, at least one of the successive contact projections on the second contact always makes contact with the contact surface, which slides along the contact projections on the contact arms, of the first contact. 
     A high contact pressure can advantageously be maintained in that the first contact is a contact blade which, in addition to the first contact surface, has a second contact surface, and in that the second contact is a sliding contact sleeve which is bent in a U-shape, wherein a first limb of the sliding contact sleeve is provided with the first multiplicity of contact arms in order to make contact with the first contact surface, and a second limb of the sliding contact sleeve is provided with a second multiplicity of contact arms in order to make contact with the second contact surface. 
     In order to make a multiplicity of electrical connections at the same time, a plurality of pairs of mutually associated first contacts and second contacts are provided, wherein the first contacts, which are provided with the contact surfaces, are arranged in a first housing in order to form a first contact module, and wherein the second contacts, which are provided with the contact arms, are arranged in a second housing, in order to form a second contact module. 
     When using the electrical contact device according to at least one embodiment of the invention, in the case of an arrangement having at least two apparatuses between which a relative movement takes place along a first movement path, wherein a first of the two apparatuses is an electrical switch, and the second of the two apparatuses is a withdrawable frame, the first contact module can be held on the electrical switch, and the second contact module can be held on the withdrawable frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantageous embodiments of the invention will be described in the following text with reference to the following figures, in which: 
         FIG. 1  shows an electrical switching arrangement comprising an electrical switch, a withdrawable frame into which the electrical switch can be inserted, and a first embodiment of the electrical contact device according to an embodiment of the invention, wherein a first contact module of the contact device is attached to the electrical switch, and a second contact module of the contact device is attached to the withdrawable frame, 
         FIGS. 2 to 4  show the first embodiment of the electrical contact device as shown in  FIG. 1 , 
         FIGS. 5 to 7  show a second embodiment of the electrical contact device, and 
         FIGS. 8 to 10  show a third embodiment of the electrical contact device. 
     
    
    
     DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS 
     Various example embodiments will now be described more fully with reference to the accompanying drawings in which only some example embodiments are shown. Specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments. The present invention, however, may be embodied in many alternate forms and should not be construed as limited to only the example embodiments set forth herein. 
     Accordingly, while example embodiments of the invention are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments of the present invention to the particular forms disclosed. On the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. Like numbers refer to like elements throughout the description of the figures. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present invention. As used herein, the term “and/or,” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that when an element is referred to as being “connected,” or “coupled,” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected,” or “directly coupled,” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between,” versus “directly between,” “adjacent,” versus “directly adjacent,” etc.). 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments of the invention. As used herein, the singular forms “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms “and/or” and “at least one of” include any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. 
     Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein are interpreted accordingly. 
     Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present invention. 
       FIGS. 1 to 4  show an electrical switching arrangement comprising a first apparatus in the form of an electrical switch  2  (in particular in the form of a low-voltage circuit breaker), a second apparatus in the form of a withdrawable frame  3 , and an electrical contact device  4  which has two contact modules  5 ,  6 . 
     According to  FIGS. 3 and 4 , a relative movement takes place between the two apparatuses along a first movement path  7 , wherein, in this case, the electrical switch  2  can be inserted into the withdrawable frame in a known manner in one movement direction, and can be withdrawn from the withdrawable frame again as well, that is to say the first movement path  7  extends in a straight line in the movement direction. 
     The first of the two contact modules of the electrical contact device  4 , which is annotated with the reference symbol  5  and is also referred to as a contact blade module, is held on the electrical switch  2 , and the second of the contact modules, which is annotated with the reference symbol  6  and is also referred to as a sliding contact module, is held on the withdrawable frame  3 . The two contact modules are used in a known manner for connection of auxiliary conductors. 
     In addition to the illustrated electrical contact device  4 , further such electrical contact devices, which are illustrated only schematically by dashed-dotted lines here, can be arranged for connection of further auxiliary conductors. 
     The second of the contact modules  6  can pivot about a shaft  8 . This shaft is borne in bearing openings  9  in holding lugs  10 , which are bent in a U-shape, of a lateral strut  11  of the withdrawable frame, and runs parallel to the lateral strut  11 , and therefore transversely with respect to the first movement path  7 . 
     According to  FIG. 2 , the first contact module  5  has a housing  12  and a plurality of first contacts  13  which are arranged parallel to one another in the housing. The second contact module  6  likewise has a housing  14 , in which a plurality of second contacts  15  are arranged, wherein two of the holding lugs engage in recesses  16 ,  17  in the left-hand side wall  18  and the right-hand side wall  19  of this housing  14 . 
     In order to mutually align mutually associated pairs of the first and second contacts, the housing  12  of the first contact module  5  forms sliding guide projections  20 , which are arranged essentially around the first contacts  13  and interact with corresponding ribs  21 , which are formed by the housing  14  of the second contact module  6  and between which the second contacts  15  extend. 
     In this case, each of the first contacts  13  is in the form of a contact blade, which forms a first contact surface  22  and a second contact surface  23 . Each of the second contacts is in the form of a sliding contact sleeve which is bent in a U-shape, wherein a first limb  24  of the sliding contact sleeve has a first multiplicity of self-supporting contact arms  26 , which are each provided with contact projections  25 , in order to make contact with the first contact surface  22 , and wherein, analogously, a second limb  27  of the sliding contact sleeve has a second multiplicity of self-supporting contact arms  29 , which are each provided with contact projections  28 , in order to make contact with the second contact surface  23 . 
     As shown in  FIG. 3 , the contact projections  25 ,  28  are arranged successively in the same direction as the first movement path  7 . 
     Therefore, during the relative movement of the two contacts  13 ,  15 —starting with an entry position of the contacts as shown in  FIG. 3 , in which the electrical switch  2  has assumed its test position in the withdrawable frame  3  and the contact surfaces  22 ,  23  make contact with the first of the contact projections  25 ,  28 , to a final position of the contacts, as shown in  FIG. 4 , in which the electrical switch  2  has assumed its operating position in the withdrawable frame  3 —at least one of the successive contact projections  25 ,  28  on each of the two limbs of the second contact  15  always makes contact with the respectively associated contact surface  22 ,  23 , which slides along the contact projections on the contact arms, of the first contact  13 . 
     During movement of the electrical switch  2 , the contact surfaces  22 ,  23  of the first contact  13 —starting in the test position of the electrical switch (entry position of the contacts) to the operating position of the electrical switch (final position of the contacts) and back—therefore carry out a sliding movement on the contact projections  25 ,  28  of the second contacts  15 . 
     In order during this process to avoid excessive wear to the contact surfaces  22 ,  23  of the first contacts, the electrical contact device  4  has a device, which is annotated  30  as an entity, for controlling a relative movement between the two contacts  13 ,  15  along a second movement path  31 , which runs parallel to the contact surfaces  22 ,  23  of the first contact  13 , and obliquely with respect to the first movement path  7 . 
     In the first embodiment  4  of the electrical contact device as shown in  FIGS. 2 to 4 , the means  30  for controlling the relative movement comprises a wedge control  32 , by which the second contact module  6 , and therefore each of the second contacts  15 , can be pivoted parallel to the contact surfaces  22 ,  23  and obliquely with respect to the first movement path  5  about the shaft  8  which runs transversely with respect to the contact surfaces. This wedge control  32  is formed by two wedge-shaped end sections  33 ,  34  of the side walls  35 ,  36  of the housing  14  of the second contact module  6 , against which an upper wall  37  of the first contact module  5  runs when the electrical switch is being inserted into the withdrawable frame. As a result of the pivoting of the second contact module in the clockwise direction about the shaft  8  that occurs during this process, the contact projections  25 ,  28  on the self-supporting contact arms  26 ,  29  slide at different points over the contact surfaces  22 ,  23  of the first contacts  13  as they slide past. 
     The self-supporting contact arms  26 ,  29  have side edges  38 , in a known manner, which extend outward and allow the respective contact blade to enter, and allow the mutually opposite self-supporting contact arms to bend away from one another. 
     In the second embodiment  104  of the electrical contact device shown in  FIGS. 5 to 7 , the means  130  for controlling the relative movement likewise comprises a wedge controller  132 . However, in this case, vertical guide surfaces  140 ,  141 , that is to say surfaces which run transversely with respect to the movement direction  107 , are formed on a lateral strut  111  of the withdrawable frame  103 , in order to move the second contact module  106  and therefore each of the second contacts  115  parallel to the contact surfaces  122 ,  123  and obliquely with respect to the first movement path  107 , which extends in the movement direction. 
     However, within the scope of at least one embodiment of the invention, it is also additionally possible for the first contact module and therefore the first contacts to be moved parallel to the first contact surface and obliquely with respect to the first movement path, or to pivot about a shaft which runs transversely with respect to the first contact surface, in addition to or instead of the second contact module. 
     As shown in  FIGS. 3 and 4  as well as  5  and  6 , the device  30 ;  130  for controlling the relative movement in the first embodiment  4  of the electrical contact device and in the second embodiment  104  of the electrical contact device has a return apparatus  42 ;  142  with a spring force which counteracts the wedge control  32 ;  132 . This return apparatus comprises a spring  43 ;  143 , which is supported on a wall  44 ;  144  of the lateral strut  11 ;  111 . 
     In the third embodiment  204  of the electrical contact device shown in  FIGS. 8 to 10 , the device  230  for controlling the relative movement comprises a wedge control  232  in the form of a positive guide, by which the second contact module  206  and therefore each of the second contacts  215  are guided such that they can be moved positively, parallel to the contact surfaces  222 ,  223  and obliquely with respect to the first movement path  207 , which extends in the movement direction. 
     For this purpose, a first pair of bent-out lugs  246 ,  247  of a left-hand side wall  248 , which is formed on the housing  212  of the first contact module  205 , clasps a first guide rib  249 , which runs obliquely with respect to the first movement path  205  and is formed on the left-hand side wall  218  of the housing  214  of the second contact module  206 . Analogously to this, a second pair of bent-out lugs  250 ,  251  of a right-hand side wall  252 , which is formed on the housing  212  of the first contact module  205 , clasps a second guide rib  253 , which runs obliquely with respect to the first movement path  205  and is formed on the right-hand side wall  219  of the housing  214  of the second contact module  206 . 
     In this case as well, vertical guide surfaces  240 ,  241 , that is to say surfaces which run transversely with respect to the movement direction  207 , are provided on a lateral strut  211  on the withdrawable frame  203 . 
     In particular when used for a switching contact arrangement which is formed from an electrical switch and a withdrawable frame—the following embodiments of the novel electrical contact device are preferred within the scope of at least one embodiment of the invention:
         a contact device  4 , in which the sliding contact sleeves are pivoted against a spring force at a rear or front rotation point relative to the movement direction,   a contact device, in which the sliding contact sleeves are positively pivoted by means of a positive guide at a rear or front rotation point relative to the movement direction,   a contact device  104 , in which the sliding contact sleeves are raised/lowered against a spring force by way of a wedge control,   a contact device  204 , in which the sliding contact sleeves are positively raised/lowered by way of a wedge control in the form of a positive guide,   a contact device, in which the contact blades are pivoted against a spring force at a rear or front rotation point relative to the movement direction,   a contact device, in which the contact blades are positively pivoted by way of a positive guide at a rear or front rotation point relative to the movement direction,   a contact device  104 , in which the contact blades are raised/lowered by way of a wedge control against a spring force, and   a contact device  204 , in which the contact blades are positively raised/lowered by way of a wedge control in the form of a positive guide.       

     The second contacts, which are provided with the contact arms, can be designed such that the contact arms which make contact in the entry position are prestressed to a lesser extent (resting with a lesser contact force on the contact surfaces of the first contact) than the contact arms which make contact in the final position. This can be achieved, for example, by the length of the separating slots between the self-supporting contact arms decreasing in the movement direction. 
     The patent claims filed with the application are formulation proposals without prejudice for obtaining more extensive patent protection. The applicant reserves the right to claim even further combinations of features previously disclosed only in the description and/or drawings. 
     The example embodiment or each example embodiment should not be understood as a restriction of the invention. Rather, numerous variations and modifications are possible in the context of the present disclosure, in particular those variants and combinations which can be inferred by the person skilled in the art with regard to achieving the object for example by combination or modification of individual features or elements or method steps that are described in connection with the general or specific part of the description and are contained in the claims and/or the drawings, and, by way of combineable features, lead to a new subject matter or to new method steps or sequences of method steps, including insofar as they concern production, testing and operating methods. 
     References back that are used in dependent claims indicate the further embodiment of the subject matter of the main claim by way of the features of the respective dependent claim; they should not be understood as dispensing with obtaining independent protection of the subject matter for the combinations of features in the referred-back dependent claims. Furthermore, with regard to interpreting the claims, where a feature is concretized in more specific detail in a subordinate claim, it should be assumed that such a restriction is not present in the respective preceding claims. 
     Since the subject matter of the dependent claims in relation to the prior art on the priority date may form separate and independent inventions, the applicant reserves the right to make them the subject matter of independent claims or divisional declarations. They may furthermore also contain independent inventions which have a configuration that is independent of the subject matters of the preceding dependent claims. 
     Further, elements and/or features of different example embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. 
     Example embodiments being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.