Patent Abstract:
A fastening system for assembling appliances, in particular electrical appliances, comprising at least one profile rail provided with openings and comprising at least one quick-fastener which has a body in which at least one internal thread is formed, is characterized in that the body has over its length (L) at least two spaced-apart internal threads, wherein, in an exact position of the quick-fastener relative to the profile rail, each of the internal threads is brought into alignment with one of the openings of the profile rail, and in that a clamping blade having the same length L as the body is attached to the body, which clamping blade forms between it and the body a gap for receiving the profile side and holds the body against the profile rail by friction.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a 371 U.S. National Stage of International Application No. PCT/DE2015/100103, filed Mar. 11, 2015, which claims priority to German Applications 10 2014 103 318.3 and 10 2014 103 338.8 both of which were filed on Mar. 12, 2014. The entire disclosures of the above applications are incorporated herein by reference. 
       FIELD 
       [0002]    The disclosure relates to a fastening system for assembling appliances, in particular electrical appliances, having at least one profile rail with openings and having at least one quick fastener with a body in which at least one internal thread is formed. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Profile rails are known in many embodiments; DE 20 2012 002 005 U1 shows one example. Known profile rails, as perforated profile rails, are provided with a row of holes to clip in cage nuts. Cage nuts are mostly square nuts that are held in a similarly square cage of sheet metal. By means of the cage, the nut can be fixed to a sheet of metal, so that a thread can be provided even on thin sheets, such as profile rails, in which a thread cannot be cut. Cage nuts are standardized in DIN 557. 
         [0005]    Normally, profile rails are attached to the side walls of racks, so that 19-inch industrial standardized appliances can be bolted to the front panel through attaching holes provided in the appliance on the left and right in said panel and held securely. Usually, the appliances are attached using four bolts in the corner areas of their front plate, sometimes also using two bolts at both ends of the center line of the front plates. The height of the front plates of the industrial standardized appliances is determined by a grid in units of height, where one unit of height is specified as 1.75 inches, or 44.45 mm. 
         [0006]    A 19-inch rack system also follows certain standards, or is standardized, for example by IEC 60297 or the corresponding metric grid system following IEC 60917. Profile rails can also be used outside of racks, right down to the individual rail that is installed horizontally or vertically. 
         [0007]    If cage nuts are to be used when attaching appliances in 19-inch rack systems, the matching profile rail has a square hole that is somewhat smaller than the cage so that a support is available between sheet metal nut to absorb axial thread forces. The cage nuts must be pre-tightened manually in order to position them in the square cutouts in the profile rails, where there is a risk of their twisting and slipping. Removing a cage nut is correspondingly laborious and often requires considerable effort. In the case of a cage nut, quick fastening is out of the question. 
       SUMMARY 
       [0008]    This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
         [0009]    The object of the present disclosure is, therefore, to provide a fastening system for assembling appliances, using which a profile rail can be equipped with an internal thread in the desired position. 
         [0010]    In accordance with the disclosure, provision is made for the body to have at least two spaced apart internal threads along its length L, whereby with the quick fastener in an exact position with respect to the profile rail, each of the internal threads is brought into alignment with one of the openings in a profile rail, and on the body a clamping blade of the same length L as that of the body is attached that forms an open space between itself and the body to receive the profile rail and that holds the body to the profile rail by friction or also by a non-positive connection. Since the internal thread is integrated into the body, an exact relative positioning of at least two internal threads is always maintained, wherein the body can be displaced along the profile rail until the alignment of the internal thread with the respective desired opening is achieved. The quick fastener is in a precise position when each of the internal threads lies above an opening in a profile rail. 
         [0011]    An internal thread in the sense of the disclosure can be a component or arrangement of components that provides a convolution in the form of an internal thread. It may be, for example, a nut. The internal thread can serve to receive a screw, a bolt or similar with a matching external thread. 
         [0012]    Because the openings lying next to each other are oriented to one another, a longitudinal direction of the profile rail is defined. The transverse direction of the profile rail, in which only one opening is covered, is defined perpendicular to the longitudinal direction. A quick fastener in accordance with the present disclosure is initially placed in the transverse direction on the profile rail and can then be moved in the longitudinal direction of the profile rail because it is being held only by frictional force. Alternatively or additionally, the quick fastener can be attached to the profile rail using non-positive connecting elements, such as latching elements that can be allocated and held precisely in position on the profile rail. Removing the quick fasteners from the profile rail is similarly possible in every position by pulling transversely, with an extra swiveling motion if necessary. 
         [0013]    In one embodiment the clamping blade is attached flexibly to the body so that it is ensured that the quick fastener can be moved to float above the profile rail without losing its frictional or non-positive connection. 
         [0014]    Furthermore, the body can be configured essentially rectangular. Provision can be made for the body to have a chamfered edge to assist when inserting onto the profile rail. 
         [0015]    It is preferable if the body has a slot for each internal thread in which a nut is positioned securely against rotation. Preferably the nut is a cage nut with a square or rectangular cross-section that sits in its assigned slot to prevent loss. 
         [0016]    Provision can further be made for the clamping blade to extend in a precise position in the transverse direction across the openings in the profile rail. In this way, the body is prevented from tipping when the quick fastener is placed on the profile rail. 
         [0017]    In order to extend the potential of screw fastening, provision should be made with at least this embodiment for the clamping blade to have openings that are aligned with an assigned internal thread on the body. 
         [0018]    In order to further ensure the frictional connection, the body and the clamping blade are arranged relative to each other in such a manner that an open space remains between them tapering towards an open longitudinal edge of the clamping blade. 
         [0019]    Furthermore, the body and/or the clamping blade can be furnished with means to increase the frictional connection to the profile rail. Said means can be fluting, for example, that forms part of the body. 
         [0020]    In accordance with a further embodiment, the clamping blade is L-shaped in cross-section, where the length of a first leg is greater than the thickness of the profile rail in the area of the openings. The length of a second leg is preferably selected in such a manner that the clamping blade at least partially overlaps the internal thread of the body. 
         [0021]    The clamping blade can have at least one recess that exposes markings formed on the profile rail in a precise position with respect to the profile rail. Such markings facilitate installation of appliances to two oppositely located profile rails without tipping. 
         [0022]    Provision can also be made for the body and/or the clamping blade to have at least one nub projecting into the open space which retains the quick fastener in a precise position with respect to the profile rail, in which position the nub is received in a recess or an opening in the profile side. 
         [0023]    The profile rail can be part of an assembly array, where the openings are equally spaced in the direction of the profile rail and where three sequential openings define one unit of height, for example of a rack frame. 
         [0024]    In order to ensure equalization in potential between the profile rail and the quick fastener, the quick fastener can have a potential equalization element that has, or consists of, an electrically conductive material and that both extends into the open space and also makes electrical contact with the internal thread or a nut or similar that provides the internal thread. 
         [0025]    The potential equalization element can further extend over a surface of the clamping blade that faces away from the open space. The potential equalization element can be integrated into the body and/or the clamping blade completely or partially, for example, integrally cast. It can also make electrical contact with the internal thread and enclose the clamping blade on one external side. 
         [0026]    Furthermore, the clamping blade can consist of a first material and the potential equalization element of a second material, where the first material is softer than the second material and where the potential equalization element projects into the open space with a supporting section that becomes a contact tip so that, when the quick fastener is positioned, the contact tip is pressed onto the profile rail through the surface of the clamping blade that faces away from the open space. The second material is preferably flexible. The potential equalization element can be configured as a contact spring. 
         [0027]    Furthermore, the contact tip of the potential equalization element can be enclosed by the first material of the clamping blade to prevent contact so that it is only pressed out of the clamping blade when the quick fastener is placed on the profile rail. 
         [0028]    In one embodiment the body is configured of plastic and the clamping blade of a metal, where the clamping blade is a single piece and connected inseparably to the body and preferably cast into the body. 
         [0029]    Furthermore, the clamping blade can have at least one contact spring on its second leg for the electrical contact with the profile rail configured as a push-through and extending into the open space. 
         [0030]    In addition, provision can be made for the clamping blade to have at least one contact spring on the surface facing away from the open space configured as a push-through to make the electrical contact with an electrical appliance. 
         [0031]    In one embodiment the quick fastener is prepared as continuous material, in rolls or in bar form with a plurality of internal threads, wherein the body of the quick fastener is divided into housing sections, equal or varying in length, each of which has a specific number of internal threads, and wherein the housing sections are connected to each other by predetermined break points. 
         [0032]    Alternatively, several quick fasteners can be disposed along a connecting strip cut to length as required while retaining the spacing or a whole-number multiple of the spacing between the internal threads. 
         [0033]    Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0034]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0035]    In what follows the disclosure is to be explained solely as an example using the attaching drawing. The representations of the Figures are not necessarily true to scale. 
           [0036]      FIG. 1  shows a perspective view of one embodiment of a quick fastener for a fastening system in accordance with the present disclosure, viewed from the side of the clamping blade; 
           [0037]      FIG. 2  shows a perspective view of the quick fastener from the side of the body; 
           [0038]      FIG. 3  shows a view of the quick fastener from which the position of the slots for receiving nuts in particular can be seen; 
           [0039]      FIG. 4  shows a further view of the quick fastener that shows how nuts are to be installed and how grounding is achieved; 
           [0040]      FIG. 5  shows a sectioned view of a quick fastener sitting on a profile rail; 
           [0041]      FIG. 6  shows a sectioned view of a quick fastener on a profile rail with a threaded connection; 
           [0042]      FIG. 7  shows a view of the quick fastener from which additional details for positioning can be seen; 
           [0043]      FIG. 8  shows a sectioned view of the quick fastener with a nub for assembly; 
           [0044]      FIG. 9  shows a perspective view of a quick fastener on a profile rail; 
           [0045]      FIG. 10  shows a structural diagram of a quick fastener; 
           [0046]      FIG. 11  shows variations of the quick fastener as they can be used in a fastening system for assembling appliances; 
           [0047]      FIG. 12  shows a sectioned view of a quick fastener with potential equalization element. 
           [0048]      FIG. 13  shows a sectioned view of a further quick fastener with potential equalization element. 
       
    
    
     DETAILED DESCRIPTION 
       [0049]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0050]      FIG. 1  shows a perspective view of one embodiment of a quick fastener  10  for a fastening system for assembling appliances, specifically electrical appliances, that is constructed from an essentially rectangular body  12  and a clamping blade  14 . The body  12  has a length L, as does the clamping blade  14 , which holds the body  12  by friction to a profile rail in the assembled position. In the present embodiment the clamping blade is L-shaped, wherein one leg  14 . 1  has a length a, second leg  14 . 2 , which runs perpendicular to the first leg  14 . 1 , has a length b. The clamping blade  14  further has two openings  14 . 3 ,  14 . 4  in the leg  14 . 2 , which, as will be further described in conjunction with  FIG. 2 , are positioned in a specific way. An approximately semi-circular recess  14 . 5  is provided centrally between the openings  14 . 3 ,  14 . 4  on the open edge of the leg  14 . 2  of the clamping blade  14 . It can be seen further from  FIG. 1  that fluting  12 . 3  is provided on the body  12  on the side that faces the clamping blade  14 . The fluting serves to improve the frictional connection between the quick fastener  10  and a profile rail. An open space  13  remains between the body  12  and the clamping blade  14  that initially narrows starting from the leg  14 . 1  towards the open end of the leg  14 . 2  and then expands again because of the particular configuration of the body  12 . 
         [0051]    The shape of the body  12  can be seen better from the perspective view of  FIG. 2 . The body  12  comprises two internal threads  12 . 1 ,  12 . 2  spaced apart from each other that are essentially aligned with the openings  14 . 3 ,  14 . 4  of the clamping blade  14  ( FIG. 1 ). The body  12  further has at its end that lies opposite the open end of the leg  14 . 2  of the clamping blade a first chamfer  12 . 4  and a second chamfer  14 . 5 . The first chamfer  12 . 4  acts as an aid to placement when being mounted on a profile rail. As a result of this chamfer  12 . 4 , the initially narrowing open space  13  between the body  12  and the clamping blade  14  is expanded again. The body  12  further has opposite its open end a step  12 . 6  to which the leg  14 . 1  of the clamping blade  14  is attached. In this way, the result is that the clamping blade  14  is attached flexibly to the body  12  whereby this measure improves the frictional connection between the quick fastener  10  and a profile rail. 
         [0052]      FIG. 3  shows the quick connector  10  from  FIG. 2  in a position rotated by about 90°, from which the location of slots  12 . 7 ,  12 . 8  can be seen particularly well, said slots being intended to receive nuts, as will be explained in conjunction with  FIG. 4 . Each slot  12 . 7 ,  12 . 8  is essentially rectangular and extends over almost the entire height H of the body  12 . The dimensions of the slots  12 . 7 ,  12 . 8  are selected in such a manner that a commercially available cage nut or any other nut can be accommodated with no risk of rotation or loss, as said dimensions are also used in the case of cage nuts. To make the thread of the cage nut accessible, the slots  12 . 7 ,  12 . 8  are provided with openings  12 . 9 ,  12 . 11  or  12 . 10 ,  12 . 12  positioned opposite each other which are aligned with the openings  14 . 3 ,  14 . 4  of the clamping blade  14  already discussed in  FIG. 1 . As a result of the inclined position of the body with respect to the clamping blade  14 , easily recognizable in  FIG. 3 , nuts sitting in the slots  12 . 7 ,  12 . 8  are prevented from accidently slipping out of the quick fastener  10 . 
         [0053]      FIG. 4  shows schematically how two nuts  40  are to be inserted into the slots  12 . 7  and  12 . 8  of the body  12 . Each nut  40  adjoins a ground clip  44  which in the assembled state is taken over the leg  14 . 1  of the clamping blade and locked to the leg  14 . 2 . In the assembled state, the nuts  40  sit in their respective slots such that their internal threads  42  align not only with the openings  12 . 9 ,  12 . 11 ;  12 . 10 ,  12 . 12  ( FIG. 3 ) of the body  12  but essentially also with the openings  14 . 3 ,  14 . 4  of the clamping blade so that the desired threaded connection is subsequently possible. 
         [0054]      FIG. 5  shows a sectioned view of a quick fastener  10  that sits on a profile rail  50 . It can be seen that length a of the first leg  14 . 1  of the clamping blade  14  is larger than the thickness d of the profile rail  50 . As a result of the fluting  12 . 3  on the body  12 , which now lies on the surface of the profile rail  50 , the frictional connection between the quick fastener  10  and the profile rail  50  is improved. A grounding strip  60  can be provided to further improve the electrical contact in the case of uncoated profile rails  50 . 
         [0055]      FIG. 6  shows the assembly situation from  FIG. 5  in a view rotated by 180°, wherein a screw  46 , as explained previously in conjunction with  FIGS. 1 to 4 , is screwed through the corresponding openings of clamping blade  14  and body  12  into the threads  42  of the nuts  40  ( FIG. 4 ), to fasten appliances (not shown).  FIG. 7  shows a further constructional detail of the quick fastener  10 , in which the clamping blade  14  has a nub  14 . 6  that extends into the open space  13  between the body  12  and the clamping blade  14  and is disposed centrally between the openings  14 . 3 ,  14 . 4  close to the recess  14 . 5 . The purpose of the nub  14 . 6  is to determine an exact position of the quick fastener  10  on a profile rail  50 . 
         [0056]      FIG. 8  shows a sectioned view of  FIG. 7  in the area of the nub  14 . 6  from which it is clear that when the quick fastener is not installed, a clearance remains between the body  12  and the clamping blade  14  even in the area of the nub  14 . 6 . 
         [0057]      FIG. 9  shows a perspective view of a quick fastener  10  that sits on a profile rail  50 . The profile rail  50  has regularly spaced openings  52 ,  54 ,  56  for each unit of height of the profile rail  50 . The number of the unit of height is given next to the respective opening, normally next to the opening in the middle, e.g.  54 . When in an exact position, the quick fastener thus sits so that the recess  14 . 5  of the clamping blade  14  reveals the marking  58  of a unit of height. Then all the openings of the quick fastener  10  align precisely with the corresponding openings (e.g.  52 ,  56 ) of the profile rail  50  so that correctly positioned assembly can be carried out using screws  46 . 
         [0058]      FIG. 10  shows a plan view of a quick fastener  10  that sits on a profile rail  50 . An additional slot  12 . 3  can be provided between the slots  12 . 7  and  12 . 8  of the body (not visible here) to expand the possibilities for assembly. 
         [0059]    As shown in  FIG. 11 , the quick fastener in accordance with embodiment (a) can be expanded into a quick fastener in accordance with embodiment (b). With an appropriate configuration of the clamping plate with an opening that, for example, can also pass through the nub (c.f.  FIG. 7 ), an appliance that comprises a front plate, for example, with a unit of height, can be fastened not just at the four corners but at alternative locations. 
         [0060]    Additional embodiments of a quick fastener are possible that are basically generated by stringing together quick fasteners in accordance with  FIGS. 1 through 8 . Thus, in the case of embodiment ( 10 ), two quick fasteners of this type are strung together, in version (d) four, in version (e) six. Connected combinations of versions (a) and (b) are also possible. 
         [0061]    All this provides a fastening system with which nuts intended for assembly can be positioned easily and which are just as easy to remove, for example, when the placement of a rack is changed. 
         [0062]      FIGS. 12 and 13  show sectioned views of two embodiments of a quick fastener  10  that has an integral potential equalization element  24 . The potential equalization element  24  is intended to equalize electrical potential between a component that is attached to the profile rail by means of the fastening system and the profile rail. With the version illustrated in  FIG. 12 , the potential equalization element  24  is configured as a contact spring that is partially integrated into the body  12  and the clamping plate  14 . In the area of the open space  13  to receive the profile rail, a supporting piece of the potential equalization element  24  projects into the open space  13 . The consequence is that when a profile rail is inserted into the open space  13 , the profile rail strikes the supporting piece  28  and pushes the contact tip  26 , which is housed in the clamping blade  14  to prevent contact, through a surface  25  of the clamping blade  14  facing away from the open space  13  out of the clamping blade  14 ; the contact tip  26  makes electrical contact for potential equalization with an appliance or component that is to be attached to the profile rail using the fastening system. Provision can also be made for the force necessary to push the contact tip  26  out of the clamping blade  14  to be generated only at the time of bolting together, so that the electrical contact for potential equalization is completed only the time of bolting together. In addition, the clamping blade  14  has an additional contact tip  27  at the opposite end from contact tip  26  that projects out of the body  12  into the open space on the side of the body  12  facing the open space  13  so that when a profile rail is pushed into the open space  13 , or at the time of bolting together, an electrical contact is made between the additional contact tip  27  and the profile rail. The clamping blade  14  and the body  12  can be made of a plastic injection molding, for example, while the potential equalization element  24  is a metallic component. Furthermore, the potential equalization element  24  can be set into the clamping blade  14 , or the body  12  respectively, in such a manner that, in the uninstalled state, only its additional contact tip  27  and the supporting section  28 , which is a folded over piece, protrude from the body  12 , or the clamping blade  14  respectively. The clamping blade  14  and the body  12  can be configured as a single plastic piece, wherein the potential equalization element  24  lends additional strength and elasticity to this plastic component consisting of body  12  and clamping blade  14 . 
         [0063]    In the embodiments shown in  FIGS. 12 and 13 , the clamping blade  14  is composed essentially of two sides arranged perpendicular to each other, which, together with the body  12 , delineate the open space  13  on three sides and leave an opening to insert a profile rail. In the embodiment depicted in  FIG. 13  a potential equalization element  24  with opposite contact tips  26 ,  27  is let into the side of the clamping blade  14  connecting the clamping blade  14  to the body  12 . In the unfinished state of the quick fastener shown in  FIG. 13 , a first contact tip  27  contacts the internal thread, for example a cage nut or similar, while the opposite contact tip  26  is positioned just below the outer surface  25  inside the clamping blade  14 . If a profile rail is inserted into the open space  13  and a fastening screw is screwed into the internal threads through the clamping blade  14 , the clamping blade  14  is deformed in such a manner that the contact tip  26  of the potential equalization element  24  comes through the surface  25  of the clamping blade  14  and makes electrical contact with the component bolted to the profile rail with the aid of the fastening system. The clamping blade  14  is preferably made from a plastic material, while the internal thread  12 . 1  can be a metal nut or similar so that the potential equalization element  24  is supported via the contact tip  27  against the internal thread  12 . 1  and makes electrical contact with said thread so that it is ensured that the potential equalization element penetrates the upper surface when bolted together. 
         [0064]    The features of the disclosure disclosed in the preceding description, in the drawings and in the claims can be essential, both individually and in any combination, to the realization of the disclosure. 
         [0065]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Technology Classification (CPC): 5