Abstract:
A profile-connecting device for connecting two profile bars. The first profile bar has an end side which abuts a longitudinal side of a second profile bar. At least the outer longitudinal side of the second profile bar which is directed toward the end side of the first profile bar and at least one outer longitudinal side of the first profile bar has an undercut groove.

Description:
This is a continuation of international application Ser. No. PCT/DE00/00245, filed Jan. 28, 2000, which was published in German. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a profile-connecting device for connecting two profile bars, in particular made of light metal, of which a first profile bar has an end side butting against a longitudinal side of a second profile bar, at least that outer longitudinal side of the second profile bar which is directed toward the end side of the first profile bar and at least one outer longitudinal side, in particular two mutually opposite outer longitudinal sides, of the first profile bar having an undercut groove. 
     Such profile bars, in particular in the form of aluminum profile bars, with outer grooves are frequently joined together in the industrial sector to form load-bearing structures for equipment. 
     PRIOR ART 
     For the assembly of aluminum profiles, a number of connections in the case of which at least one profile, in some cases both profiles, have to be machined, i.e. provided with bores or milled recesses, are known. In addition to the machining costs, the profile elements provided are often difficult and thus expensive to produce. 
     In addition, the profile machining usually weakens the strength of the profiles precisely in the connection region. In the case of some of the known connections, the tightening or connecting moment is non-uniform and thus is not optimum. 
     The self-tapping screws used for a fair number of profile-connecting devices shift the machining problem to the assembly stage. 
     EP-B1-0 460 360 discloses a profile-connecting device of the type mentioned in the introduction. In this case, a flange is connected to at least one sliding block, which is screwed in an inner chamber of the first profile bar via a screw. In the axial direction of the groove of the first profile bar, the flange is then screwed, via a screw-connection element, to sliding blocks arranged in the groove of the second profile bar. 
     EP-0 233 525 also discloses a profile-connecting device which uses a flange which is screwed in the inner chamber of the first profile via a screw, an arresting part having been introduced in the inner chamber beforehand and secured there in a form-fitting and/or force-fitting manner. 
     DESCRIPTION OF THE INVENTION 
     Taking the abovementioned prior art as the departure point, the technical problem or the object on which the present invention is based is to avoid the disadvantages specified in the prior art and to specify a profile connector which ensures a stable connection between the profiles with a uniform tightening or retaining moment without any machining of the profiles. An additional intention is to allow quick installation of the connection, which can be introduced directly in the connection region without preliminary machining of the profiles being necessary. 
     A further technical problem is to specify a profile-connecting device which can also be introduced subsequently into an existing structure without the existing structure having to be dismantled. 
     The profile-connecting device according to the invention is provided by the features of independent claim 1. Advantageous configurations and developments form the subject matter of the dependent claims. 
     Accordingly, the profile-connecting device according to the invention of the type mentioned in the introduction is characterized by a clamping unit which, at least in certain regions, has an outer contour which can be clamped in the groove by virtue of being widened, a screw unit which can be introduced into a continuous cutout of the clamping unit, and a threaded unit which can be introduced with rear-engagement action into the groove of the second profile bar, the clamping unit being spread apart, and thus clamped in the groove of the first profile bar, by virtue of the screw unit, which is introduced into the clamping unit, being screwed into the threaded unit, and a partially clamping and partially form-fitting connection between the two profile bars being produced in conjunction with the threaded unit, via the screw unit. 
     A particularly advantageous development of the profile-connecting device according to the invention is distinguished in that the screw unit is designed as a wedge screw with flanks which are inclined in certain regions, and the clamping unit has correspondingly inclined mating flank regions, a particularly advantageous configuration being distinguished in that the inner contour of the mating flank regions of the clamping unit is formed with a self-locking slope, this making it possible to ensure a permanently reliable connection. 
     A particularly preferred alternative configuration is distinguished in that the clamping unit has a base plate with a width which corresponds to the groove width of the profile bar, and at least two clamping elements, which can be spread apart by the threaded unit, are integrally formed on the base plate, flush with the outside of the latter, with the result that, in the non-spread-apart state, the clamping unit can be pushed at least into the groove of the first profile bar and/or, in certain regions, into the groove of the second profile bar. Since the clamping unit has the same width as the groove of the profile bar, screwing the screw unit into the threaded unit, in addition to the spreading action, causes the profiles to be centered automatically as soon as the screw connection engages with the threaded unit, which may preferably be a hammer nut. 
     A configuration which is particularly preferred in terms of production and straightforward handling is distinguished in that the clamping elements each have a shoulder which, in the inserted and spread-apart state of the clamping unit, engages, at least in certain regions, behind the groove of the first profile bar, and, in one development, the shoulder depth increases from the base plate to the opposite end region of the clamping elements, that is to say it is possible to set a very high clamping pressure, when the clamping unit is spread apart, in the regions adjoining the base plate. 
     The regions which, in the inserted and spread-apart state, butt against the groove wall within the opening width contain knurling, as a result of which the clamping force can be reliably increased. 
     A possible material for the clamping unit and/or centering unit is preferably an aluminum/zinc pressure die casting or steel. 
     The clamping unit and/or centering unit may also be in the form of a precision forging. 
     As the threaded unit, use is preferably made of a hammer nut or of a sliding block, in particular a spring-activated sliding block. 
     A configuration which is advantageous particularly in terms of the connection forces and moments transmitted is distinguished in that in each case one clamping unit with centering and screw unit is arranged in the two mutually opposite grooves of the first profile unit, the screw unit being screwed into in each case one threaded unit or, alternatively, into a common threaded unit, which has two bores corresponding to the spacing between the two grooves. 
     Straightforward and quick installation is further assisted, in an advantageous configuration, in that the screw unit, on the top side, has a contour for the engagement of a tool, which contour is preferably in the form of a polygonal socket contour. 
     Further embodiments and advantages of the invention can be gathered from the features additionally given in the claims and from the exemplary embodiments specified hereinbelow. The features of the claims may be combined with one another in any desired manner provided that they are not obviously mutually exclusive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention and advantageous embodiments and developments of the same are explained and described in more detail hereinbelow with reference to the example illustrated in the drawing. The features which can be gathered from the description and the drawing can be used according to the invention individually or in any desired combination. In the drawing: 
     FIG. 1 shows an exploded schematic illustration, in perspective, of a clamping unit with screw unit and threaded unit for connecting a first and a second profile bar (detailed), and 
     FIGS. 2 a ) and  b ) show schematic sectional illustrations through the first profile bar with a plan view of the clamping unit according to FIG. 1 in the groove of the second profile bar in the inserted state a) and in the spread-apart, connecting state b). 
    
    
     METHODS OF IMPLEMENTING THE INVENTION 
     FIG. 1 illustrates two profile bars  20 ,  30  which are connected to one another at right angles. A first profile bar  20 , coming from the top, has its end side connected to an outer surface of a profile bar  30 , which is arranged horizontally in FIG.  1 . Both profile bars  20 ,  30  are in the form of aluminum profile bars which have a square outer peripheral contour, a respective longitudinally continuous groove  22  or  32  being provided on each outer side. 
     The connection takes place via a profile-connecting device  10 , which is constructed as follows: 
     First of all each profile-connecting device  10  has a clamping unit  13 , which has two clamping elements  13 . 1 ,  13 . 2 . 
     In their top region, the clamping elements  13 . 1  have an inwardly inclined mating flank region  26 . With the elements  13 . 1 ,  13 . 2  inserted into the groove  22 , it is possible to introduce between the two clamping elements  13 . 1 ,  13 . 2  a screw unit  14  which has an external thread  36 , is designed as a wedge screw and has flanks  24  which are likewise inclined correspondingly to the mating flank regions  26  of the clamping elements  13 . 1 ,  13 . 2  and, in the inserted state, come into abutment with the mating flanks  26 . 
     The head of the screw unit  14 , on the top side, has a hexagonal socket contour  28  for the engagement of a tool. 
     The profile-connecting device  10  also has a threaded unit  16  which, in the exemplary embodiment, is designed as a known hammerhead nut with an internal thread  34  and can be inserted into the groove  32  of the second profile bar  30 , with rear engagement of the groove  32 . 
     In an exemplary embodiment which is not illustrated, use is made of a threaded element which passes through the entire groove  32  and, corresponding to the spacing between the two screw units and/or the grooves  22  of the first profile bar, has bores with threads at the same spacing. 
     The clamping unit  13 , on the underside, has a base plate  50  of width B which corresponds to the groove width B of the first profile bar  20  and of the second profile bar  30 . The two separate clamping elements  13 . 1  are integrally formed on the top side of the base plate  50 , and do not project beyond the width B. These two clamping units  13 . 1 , in their interior, form a continuous cutout  27  with a corresponding mating flank  26  for the flank  24  of the screw-connection unit  14 . 
     The clamping elements  13 . 1 ,  13 . 2 , on the outside, have a shoulder  52  which increases in depth from the base plate  50  to the mutually opposite end border. This results in an inclined surface which, according to the exemplary embodiment illustrated, contains transverse ribs or knurling  54 . 
     As threaded unit  16 , use is made of a hammer nut  16 , which is known as such and can then easily be inserted into groove  32  of the second profile bar  30 . By virtue of the screw unit  14  being turned, the hammer nut  16  initially turns along with it and then swings round in the groove  32  of the second profile bar  30 . 
     The screw-connection unit  14 , the clamping unit  13  and the threaded unit  16  can form a preassembled installation unit by virtue of the screw-connection unit  14  being screwed into the internal thread  34  of the threaded unit  16  to a slight extent, with the result that the clamping elements  13 . 1  of the clamping unit  13  are not spread apart. In this preassembled state, it is possible for the connecting device  10 , with the hammer nut  16  in an appropriate position, to be introduced into the groove  32 . This position is illustrated in FIG. 2 a ). Since, in this state, the base plate  50  engages, in certain regions, in the groove  32  of the second profile bar  30 , a certain centering action has already been provided for in this preassembled state. The connecting device  10  is then pushed along the groove  32  into the groove  22  of the first profile bar. This is possible since the outer dimensions of the clamping unit  13  do not exceed the dimensions of the groove. If the screw-connection unit  14  is then turned, the hammer nut  16  initially turns in the groove  32  until, finally, it swings round. Further turning of the screw-connection unit  14  forces the flank  24  of the latter onto the corresponding mating surface  26  of the clamping elements  13 . 1 , as a result of which said clamping elements  13 . 1  are spread apart laterally. In the final spread-apart state of the clamping elements  13 . 1 , the arrangement is such that the two stop surfaces  52  engage, at least in certain regions, behind the inner wall of the groove  22 , with the result that, in this state, it is no longer possible, as a result of the form fit, for the connecting device  10  to be drawn out of the groove  22 . At the same time, the clamping elements  13 . 1  of the clamping unit  13  are forced apart from one another, with the result that those surfaces of the clamping elements  13 . 1  which are located in front of the shoulder  52  in each case are pressed with clamping action, by way of the knurling  54 , against the wall of the opening of the groove  22 . 
     The profile-connecting device  10  illustrated provides an assembly aid by means of which two profile bars  20 ,  30 , with grooves  22 ,  32 , which are positioned perpendicularly one upon the other are connected reliably and in the case of which it is not necessary for installation parts to be introduced from the free end sides of the groove  22  or  32  or for possible bores to be produced. The assembly operation is extremely straightforward and a permanently reliable connection is ensured.