Patent Publication Number: US-2019191872-A1

Title: Connector

Description:
The invention relates to a connector for connecting a support and a frame disposed so as to be perpendicular thereto. 
     An exhibition construction system in which a so-called tension lock is used as a connector for connecting a support, in other words an upright, and a frame, in other words a beam, disposed so as to be perpendicular thereto is known from European patent document EP 0 976 891 B1. The tension lock has two hooks which engage in an undercut groove in the support. The hooks can be retracted by means of an eccentric in the tension lock such that, on account thereof, an end side of the frame is pulled toward a lateral face of the support. A force-fit which ensures a secure fixing of the frame to the support is created on account thereof. The force-fit between the frame and the support as well as between the hooks of the tension lock and the undercut of the groove can be overcome in the event of very high forces arising. The hooks form the extension in terms of length of a spring in the tension lock. The connection is released in the event of a failure of the spring. 
     By way of the invention, a connector for connecting a support and a frame disposed so as to be perpendicular thereto is to be improved in terms of the load-bearing capability of the connection. 
     To this end, a connector having the features of claim  1 , and a connection assembly having the features of claim  7 , are provided according to the invention. Advantageous refinements of the invention are stated in the dependent claims. 
     A connector for connecting a support and a frame disposed so as to be perpendicular thereto is provided, in which the connector has at least one bolt or hook having an undercut which is configured for engaging in a keyhole-shaped through opening on the frame or support, wherein the dimensions of a front end portion of the bolt are adapted to a wider portion of the through opening, and the dimensions of the undercut are adapted to a narrower portion of the through opening, wherein a housing of the connector is capable of being fixed to the end side of the support or frame, and wherein the at least one bolt or hook is disposed so as to be displaceable parallel with a longitudinal direction of the support or frame, in particular is disposed so as to be displaceable in the housing of the connector. 
     In this way, the bolt, or else the entire connector, respectively, can assume a retracted position or assembly position in which the connector, and thus also the bolt, does not protrude beyond the end side of the frame or the support, respectively. On account thereof, a frame can also be inserted between two already fixedly assembled supports, since a length not larger than the spacing between the already fixed supports is required for inserting the frame, said length corresponding to the length of the frame. 
     In a refinement of the invention, a safety installation which in a secured position fixes the bolt in the narrower portion of the through opening can be provided. 
     The bolt can be fixed in a form-fitting manner in the keyhole-shaped through opening by means of the bolt and of the keyhole-shaped through opening. This does not apply only to a direction in which the undercut of the bolt is introduced into the narrower portion of the through opening and is also guided out of the latter. The safety installation is provided in order for the bolt to also be fixed in a form-fitting manner in the keyhole-shaped through opening in said direction. On account thereof, the bolt in the secured position of the safety installation is fixed, in particular in a form-fitting manner, in all spatial directions in the narrower portion of the through opening. Even in the case of very high forces which act on the support or frame, the connector reliably absorbs the forces and reliably directs said forces into the support or the frame, respectively by way of the bolts. The at least one bolt or hook can be disposed so as to be rigid or displaceable on the connector. To this end, the bolt or hook can be displaceable relative to a housing of the connector which is fixed to the support or frame. Alternatively, the connector per se is disposed so as to be displaceable in the support or frame. 
     In a refinement of the invention the safety installation includes the secured position and an assembly position, wherein the safety installation in the assembly position fixes the front end portion of the bolt so as to be in line with the larger portion of the keyhole-shaped through opening. 
     In that the safety installation in the assembly position fixes the bolt so as to be in line with the comparatively large portion of the keyhole-shaped through opening, an assembly and the disassembly of the connector is significantly facilitated. For example, the safety installation is moved to the assembly position, and the bolts are subsequently displaced from the narrower portion of the keyhole-shaped through opening to the wider portion of the keyhole-shaped through opening. Before the undercut now can latch on the upper periphery of the wider portion of the keyhole-shaped through opening, the safety installation prevents such a movement and aligns the front end portion of the bolt so as to be in line with the wider portion of the keyhole-shaped through opening. The bolts, proceeding from this position, can then be readily extracted from the wider portion of the keyhole-shaped through opening. The safety installation advantageously configures a dual-step detent. The safety installation in the first step is located in the secured position and fixes the bolt in the narrower portion of the through opening. The safety installation in the second step aligns the bolt so as to be in line with the wider portion of the key-hole shaped through opening. For example, the bolt in the second step of the safety installation can be displaced out of the narrower portion of the through opening and into a position in which the front end portion of said bolt is aligned so as to be in line with the wider portion of the keyhole-shaped through opening. 
     In a refinement of the invention the safety installation has a safety pin which is displaceable parallel with the bolt. 
     A very reliable and at the same time easily operable safety installation can be achieved by means of a safety pin. The safety pin in the secured position thereof can provide for a form-fit between the safety pin and thus the connector and a receptacle bore for the safety pin in the support or frame. 
     In a refinement of the invention the safety pin has a step-shaped detent at the front end. 
     The step in this instance can form a dual-step detent at the front end of the safety pin. When the first or upper face of the detent bears on a safety bore, the bolt by way of the undercut thereof is fixed in the narrower portion of the keyhole-shaped through opening. This forms the secured position of the safety pin. When the second or lower face of the detent stops at the periphery of the safety bore, the bolts can be displaced from the narrower portion of the keyhole-shaped through opening so far in the direction toward the wider portion until the front end portion of the bolt is disposed so as to be in line with the wider portion of the keyhole-shaped through opening. The bolts in this position can then be extracted from the wider portion. 
     In a refinement of the invention the safety pin in the secured position engages in a safety bore in the support or frame, said safety bore being separate from the keyhole-shaped through openings. 
     It is enabled in this way that the front end portions of the bolts in the assembly position of the safety pin can be aligned so as to be in line with the wider portion of the keyhole-shaped through opening, since the safety pin per se does not block any part of the keyhole-shaped through opening. The safety bore is configured as an elongate hole, for example. The safety bore as an elongate hole can be configured on the base of an undercut groove of the support or frame. Both the support as well as the frame are expediently configured as a tubular hollow section having an identical cross-section, and are produced as a pultruded aluminum section, for example. 
     In a refinement of the invention a tension lock which engages in an undercut groove in the support or frame is provided. 
     Additional securing in the form of a friction-fit between the frame and the support can be established by means of such a tension lock. For example, the frame can also be rapidly and readily preassembled in the envisaged position by means of the tension lock, and the bolt can only be subsequently fixed in the keyhole-shaped through openings. Of course, an assembly is also possible in the reverse manner. The tension lock in this instance can ensure a gap-free bearing of the end side of the frame on the lateral face of the support. The provision of a tension lock which in the assembled state pretensions the end side of the frame in relation to the lateral face of the support enables pretensioning of the bolts in the keyhole-shaped through openings to be dispensed with. The bolt by way of the undercut thereof can especially also in the assembly position be disposed with play in the narrower portion of the through opening. As soon as a force is exerted on the bolt, the bolt is braced in relation to the periphery of the keyhole-shaped through opening. In order for a visual appeal of the connection between the frame and the support to be obtained, and also in order to avoid any rattling of the connection, a force-fit by means of the tension lock can in this instance be additionally established between the frame and the support. 
     In a refinement of the invention a housing of the connector is capable of being fixed to the end side of the support or frame. 
     The connector by means of a housing can be reliably fixed to the support or frame. The housing is configured as a profile or extension, for example, the external side thereof being configured so as to match an internal side of the hollow section for the supports and frames. On account thereof, the housing can be push-fitted in a very simple manner into the hollow profile which forms the support and/or the frame. On account thereof, the housing of the connector is fixed in directions of movement perpendicular to a longitudinal axis of the support or frame solely by push-fitting. 
     In a refinement of the invention the bolt by means of a tensioning installation can be braced between the connector and the narrower portion of the keyhole-shaped through opening. 
     In this way, a gap between an end side of the frame and the lateral face of the support can be reduced to zero by means of the tensioning installation, and an additional force-fit can be generated. An additional tension lock can optionally be omitted in the case of such a design embodiment of the connector. A tensioning installation for the bolt can be embodied by means of an eccentric, for example. Just like the hooks of the tension lock can be moved by means of an eccentric, this is also possible in the case of the bolts. 
     In a refinement of the invention the bolt is disposed on an adapter which is disposed so as to be displaceable in the housing of the connector. 
     In this way, the housing of the connector per se can be disposed so as to be secure and immovable in the frame or support. The retraction function of the bolts can be implemented by way of a displacement of the adapter in the housing of the connector per se. 
     In a refinement of the invention four bolts are provided. 
     It has been demonstrated that forces in all spatial directions as well as moments about all spatial directions can be reliably absorbed by the bolts and directed onward into the frame and/or support when four bolts which are in particular disposed on the corner points of a rectangle or square are provided. 
     In a refinement of the invention the tension lock is disposed so as to be substantially centric to the four bolts. 
     Such an arrangement of the tension lock has proven very advantageous, also for reasons of space. 
    
    
     
       Further features and advantages of the invention are derived from the claims and from the description hereunder of preferred embodiments of the invention in conjunction with the drawings. Individual features of the various embodiments described and illustrated herein can be combined with one another in an arbitrary manner without exceeding the scope of the invention. In the drawings: 
         FIG. 1  shows a partially sectioned connector according to the invention and a frame illustrated in portions in an exploded illustration; 
         FIG. 2  shows the connector and the frame of  FIG. 1  in the assembled state in a secured position; 
         FIG. 3  shows a side view of the connector and the frame of  FIG. 2  in the secured position; 
         FIG. 4  shows the connector and the frame of  FIG. 2  in an assembly position; 
         FIG. 5  shows a side view of the connector and the frame of  FIG. 4  in the assembly position; 
         FIG. 6  shows a front view of the connector and the frame of  FIG. 4 ; 
         FIG. 7  shows the connector of  FIG. 1  in an enlarged illustration; 
         FIG. 8  shows a partially sectioned view of the connector of  FIG. 7 ; 
         FIG. 9  shows a front view of the connector of  FIG. 7 ; 
         FIG. 10  shows a plan view of the connector sectioned along the line A-A in  FIG. 9 ; 
         FIG. 11  shows a connector according to a further embodiment of the invention, and a frame illustrated in portions, in an exploded illustration; 
         FIG. 12  shows the connector and the frame of  FIG. 11  in the assembled state in a secured position; 
         FIG. 13  shows a side view of the connector and the frame of  FIG. 12  in the secured position; 
         FIG. 14  shows the connector and the frame of  FIG. 12  in an assembly position; 
         FIG. 15  shows the connector and the frame of  FIG. 14  in a side view, in the assembly position; 
         FIG. 16  shows the connector and the frame of  FIG. 14  in a retracted position; 
         FIG. 17  shows a side view of the connector and the frame of  FIG. 16 ; 
         FIG. 18  shows a front view of the connector and the frame of  FIG. 12 ; 
         FIG. 19  shows an enlarged illustration of the connector of  FIG. 11 ; 
         FIG. 20  shows a partially sectioned view of the connector of  FIG. 19 ; 
         FIG. 21  shows a front view of the connector of  FIG. 19 ; 
         FIG. 22  shows a plan view of the connector of  FIG. 21 , sectioned along the line A-A; 
         FIG. 23  shows an isometric illustration of a framework from obliquely below, said framework being constructed from supports and frames which are connected to one another by means of the connector according to the invention; 
         FIG. 24  shows a side view of the framework of  FIG. 23 ; 
         FIG. 25  shows a side view of a support and frame connected to one another, from the framework of  FIG. 23 ; 
         FIG. 26  shows an enlarged illustration of portions of a connection region between the support and the frame of  FIG. 25 ; 
         FIG. 27  shows an enlarged illustration of portions of the frame of  FIG. 25 ; 
         FIG. 28  shows a further enlarged illustration of portions of the frame of  FIG. 25 ; 
         FIG. 29  shows a plan view of the arrangement having the support and the frame of  FIG. 25 ; 
         FIG. 30  shows a connector according to a further embodiment of the invention, obliquely from the front; and 
         FIG. 31  shows the connector of  FIG. 30  obliquely from the rear. 
     
    
    
     The illustration of  FIG. 1  shows a connector  34  which is provided for being push-fitted into the end side of a frame  14  and to be fixed therein. The frame  14  is configured as a a tubular hollow profile, the interior thereof being configured so as to match a housing  50  of the connector. The connector  34  has four bolts  42  which protrude beyond the end side of the housing  50 . Each of the bolts  42  has an annular groove  41  which is formed between a head of the bolt and an annular flange of the bolt, and which forms an undercut. The bolts, by means of a threaded portion (not visible in  FIG. 1 ) are screwed into an annular receptacle duct in the housing  50 . The housing  50 , as is also the frame  14 , is configured as a profile, in particular as a pultruded or extruded aluminum profile. 
     The connector  34  has a safety pin  44  which in a receptacle duct of the housing  50  can be displaced in and counter to a longitudinal direction of the connector. An adjustment screw  38  is provided for displacing the safety pin  44 . The safety pin  44  by means of a compression spring (not visible in  FIG. 1 ) which is disposed in the receptacle duct is pretensioned to a secured position illustrated in  FIG. 1 . The adjustment screw  38  can be moved between two terminal detents which are formed by the periphery of an elongate hole  32  in the housing  50 . The connector  34  is moreover provided with a tension lock  68  which is push-fitted into a centric receptacle chamber in the housing  50  and which can be activated by means of an eccentric (not visible in  FIG. 1 ). The eccentric is accessible by way of a bush  52 . To this end, a side wall of the housing is provided with a through opening  54  which in  FIG. 1  is illustrated so as to be significantly larger than implemented in reality, so as to render the bush  52  visible. The tension lock  68  has two hooks  70  which can be hooked into an undercut groove of a support. The connector can moreover be provided with a guide pin  56  which likewise protrudes beyond an end side of the housing  50  and which, like the hooks  70 , is provided for engaging in an undercut groove of a support. To this end, the support has at least one undercut groove  26  as can be seen on the frame  14 . 
     The bolts  42  are provided for engaging in keyhole-shaped through openings of a support. To this end, a group of four keyhole-shaped through openings is provided on the support, cf.  FIG. 26 . A group of four keyhole-shaped through openings is provided in all lateral faces of the support  12 , this however not being visible in  FIG. 26 . The frame  14  is also provided with groups of four keyhole-shaped through openings, cf.  FIG. 25 . The frame  14  on the left and right end thereof in  FIG. 25  is in each case provided with one group of two keyhole-shaped through openings  24  which conjointly with further keyhole-shaped through openings on the support  12  then again form one group of four keyhole-shaped through openings  24  into which the bolts  42  of the connector  34  can then engage. In the case of the embodiment illustrated, four bolts  42  are provided on the connector  34 , and in a matching manner thereto, groups of at least four keyhole-shaped through openings  24  are in each case provided on the support  12  or the frame  14 , respectively. However, in the context of the invention the provision of a single bolt  42  which in this instance also engages in a single keyhole-shaped through opening  24  is also sufficient. 
     As can be seen in  FIG. 26  and  FIG. 27 , the keyhole-shaped through openings  24  have in each case a wider portion  30  and a narrower portion  28 . The wider portion  30  has a segment-shaped periphery and in terms of the diameter thereof is adapted to the diameter of the front end of the bolt  42 , such that the bolts  42  can be introduced in the wider portion  30  of the keyhole-shaped through openings  24 . The dimension of the groove  41  on the bolts  42  is adapted to the dimensions of the narrower portion  28  of the keyhole-shaped through openings  24 . When the bolts, after having been introduced into the wider portion  30  in  FIG. 26 , are moved downward, parallel with the central axis  32  of the keyhole-shaped through opening  24 , the free end of the bolt  42  thus engages behind the periphery of the narrower portion  28  of the keyhole-shaped through opening  24 , since the periphery comes to lie in the groove  41 . The bolt  42  in this instance by way of a portion of the base of the annular groove  41  bears on the lower periphery of the narrower portion  28 . The bolt by the lateral delimitations of the narrower portion  28  is blocked in relation to any displacement of the bolt  42  in the lateral direction relative to the keyhole-shaped through opening  24 . The lower delimitation  34 , embodied in a rectilinear manner, of the keyhole-shaped through opening  24  ensures a form-fitting fixing of the bolt  42  in relation to any downward movement. The lower delimitation  34  herein is embodied so as to be rectilinear in order to enable a certain lateral movement of the bolt  42  for equalizing tolerances within the narrower portion  28  of the keyhole-shaped through opening  24 . 
     When the bolt by way of the groove  41  thereof is located in the narrower portion  28  of the keyhole-shaped through opening  24 , said bolt is thus fixed in a form-fitting manner in the direction of movement toward the left, toward the right, and downward, cf.  FIG. 26 . Only an upward movement, thus in the direction toward the wider portion  30 , is still possible. Such a movement is in this instance prevented by the safety pin  44  which in portions engages in the safety bore  46  in the support  12 , cf.  FIG. 26 . The safety bore  46  in the case of the embodiment illustrated is embodied as an elongate hole. The connector  34  in such a secured position of the safety pin  44  in a form-fitting manner is thus fixed in all spatial directions to the support  12 . On account thereof, the frame  14  which is connected to the support  12  by means of the connector  34  is likewise reliably secured on the support  12 . The tension lock  68 , the hooks  70  thereof engaging in the undercut of the groove  26  on the support  12 , moreover ensures a force-fit between the end side of the frame  14  and the assigned lateral face of the support  12 , and also ensures that no play whatsoever remains between the end side of the frame  14  and the lateral face of the support  12 . 
       FIG. 27  shows a group of four keyhole-shaped through openings  24  in the frame  14 . By means of the connector  34 , two frames can be connected to one another by means of said keyhole-shaped through openings. 
     It can be seen in the illustration of  FIG. 29  that the bolts  42  in the assembled state by way of the front end portion thereof protrude into the interior of the support  12 . Two of the four bolts  42  can likewise be seen at the right end of the frame  14  in  FIG. 29 , and it can also be seen that the groove  41  still protrudes beyond the end side of the frame  14  such that said groove in the assembled state can engage in the narrower portions  28  of the keyhole-shaped through openings  24 . 
     It can furthermore be seen in  FIG. 1  that the housing  50  of the connector  34  has four grooves  82  which are in each case mutually spaced apart by 90°. In a manner matching thereto, the frame  14  has four strip-shaped protrusions  84  which protrude into the interior of the frame  14  and which ensure longitudinal guiding of the housing  50  after push-fitting into the frame  14 . As has already been explained, the housing  50  of the connector  34 , after push-fitting into the frame  14  is already fixed to the extent that said housing  50  can still only be displaced in and counter to the longitudinal direction of the frame  14 . Fixing screws  36  which can be screwed into the threaded bores in the housing  50 , which emanate from the base of the grooves  82 , are provided in order for the housing  50  to be fixed relative to the frame  14 . After the push-fitting of the connector  34  into the frame  14 , the fixing screws  36  are introduced into countersunk bores  48  on the base of the undercut grooves  26  of the frame  14  and screwed into the threaded bores in the housing  50 . On account thereof, the housing  50  is then reliably fixed in the frame  14 . When the countersunk bores  48  are embodied as elongate holes, the connector  34  after the location of the fixing screws  36  can be displaced in and counter to the longitudinal direction of the frame  14 , for example in order for the end side of the bolts  42  for assembling the frame to be retracted level with the end side of the frame  14  or behind the end side of the frame  14 . 
     The connector  34  and the frame  14  in the illustration of  FIG. 2  are illustrated in the assembled state. An eccentric of the tension lock  68  is now accessible by way of a lateral bore  86  in the frame  14 . As has already been explained, the safety pin  44  by means of the adjustment screw  38  can be displaced in and counter to the longitudinal direction of the frame  14 , wherein the adjustment screw  38  is accessible by way of an elongate hole  88  in the upper side of the frame  14 . 
     The illustration of  FIG. 3  shows a secured position of the safety pin  44 . It can be seen in the side view of  FIG. 3  that the safety pin  44  in the secured position thereof protrudes beyond the front end of the bolts  42 . An upper side  45  of the safety pin  44  in the secured position stops at the upper periphery of the safety bore  46 , cf.  FIG. 26 , and on account thereof prevents the bolts  42  being moved out of the narrower portions  28  of the keyhole-shaped through openings  24 . Rather the bolts are fixed such that said bolts by way of the angular grooves  41  thereof are disposed in the narrower portions  28  of the keyhole-shaped through openings  24 . The connector  34  in this secured position is thus fixed in a form-fitting manner in the keyhole-shaped through openings  24  of the support  12 . 
     It can furthermore be seen in  FIG. 3  that the hooks  70  of the tension lock  68  protrude beyond the end side of the frame  14 . As has already been explained, the hooks  70  by means of activating an eccentric  90  can be moved in and counter to the longitudinal direction of the frame  14 , thus from right to left, or from left to right, respectively, in the illustration of  FIG. 3 . On account thereof, the hooks can engage in the undercut of the groove  26  in the support  12 , cf.  FIG. 26  and  FIG. 29 , so as to on account thereof pull the end side of the frame  14  toward the end face of the support  12  and to establish a force-fit therebetween. 
     The illustration of  FIG. 4  shows the connector  34  and the frame  14  in an assembly position of the safety pin  44 . As can be seen in  FIG. 5 , the safety pin  44  now protrudes less far beyond the end side of the frame  14  as was the case in the secured position of  FIG. 3 . The upper side  45  of the safety pin  44  in the secured position of  FIG. 3  protrudes beyond the front end of the bolts  41 . In the assembly position of  FIG. 5  only a face of the step-shaped detent  43  still protrudes beyond the front end of the bolts  42 , said face being disposed so as to be parallel with the displacement direction of the safety pin, thus so as to be horizontal in the installed position of the frame. In this assembly position of  FIG. 5 , consequently only the step-shaped detent  43  still engages in the safety bore  46  on the base of the groove  26  of the frame  12 , cf.  FIG. 26 . Since the step-shaped detent  43  in the view of  FIG. 5  lies lower than the upper side  45  of the safety pin  44 , cf. also  FIG. 3 , the frame  14  can now be pushed further upward relative to the support  12 , until the horizontal face of the step-shaped detent  43  thus stops at the upper delimitation of the safety bore  46 , cf.  FIG. 26 . In this position, the front ends of the bolts  42  are now aligned so as to be in line with the wider portions  30  of the keyhole-shaped through openings  24 . The frame  14  in this instance can be removed from the support  12  to the right in a simple manner, cf.  FIG. 26 , since the front ends of the bolts  42  can be guided out of the wider portions  30  of the keyhole-shaped through openings  24 . 
     The assembly position of  FIG. 5  of the safety pin  44  is achieved in that the securing screw  38 , cf.  FIG. 1 , is displaced to the rear, thus to the top right in  FIG. 1 , until said securing screw  38  stops at the delimitation of the elongate hole  32  that lies at the top right in  FIG. 1 . 
     The illustration of  FIG. 6  shows a front view of the connector  34  installed in the frame  14 . It can be readily seen in this view how the strip-shaped protrusions  84  of the frame  14 , which protrude into the interior of the tubular hollow section which forms the frame  14 , engage in the grooves  82  of the housing  50  of the connector  34  and on account thereof secure the housing  50  in the frame  14 . As has already been explained, the fixing screws  36  in this instance serve for finally fixing the housing  50  relative to the frame  14 . The housing  50  is configured as a hollow section and has the four receptacle ducts into which the bolts  42  are screwed. A central chamber having a rectangular cross section serves for receiving the tension lock  68 . The safety pin is received so as to be displaceable in a further receptacle duct having an approximately circular cross section. The guide pin  56  can be disposed on that side of the tension lock  68  that is opposite the safety pin. 
     The illustration of  FIG. 7  shows the connector  34  of  FIG. 1  in an enlarged illustration. 
       FIG. 8  shows the connector  34  so as to be partially sectioned. It can be seen in this view that a compression spring  92  is disposed within the receptacle duct for the safety pin  44 , said compression spring  92  being supported on a closure plug  94  of the receptacle duct, on the one hand, and on the rear side of the safety pin  44 , on the other hand. The compression spring  92  pretensions the safety pin  44  to the secured position illustrated in  FIG. 3  and  FIG. 7 . When the safety pin  44  is retracted to the assembly position illustrated in  FIG. 5 , the adjustment screw  38  to this end has to be moved counter to the force of the spring  92 . In the assembled state of the frame  14  on the support  12 , cf.  FIG. 26 , the securing screw  38  can be completely screwed in so as to on account thereof fix the safety pin  44  in the secured position. 
     It can be furthermore seen in the illustration of  FIG. 8  how the bolts  42  by way of the threaded portion thereof are screwed into the receptacle ducts in the housing  50 . 
       FIG. 9  shows a front view of the connector  34  of  FIG. 7 .  FIG. 10  shows a view of the connector  34  which is sectioned along the line A-A in  FIG. 9 . 
     The illustration of  FIG. 11  shows a connector  104  according to a further embodiment of the invention, as well as the frame  14 , wherein the frame  14  and the connector  104  are illustrated in the exploded state, thus prior to the connector  104  being inserted into the end side of the frame  14 . 
     The connector  104  differs from the connector  34  of  FIG. 1  in that a retraction function of the bolts  42  is additionally implemented. Such a retraction function is required when the frame  14  has to be installed between two already fixedly assembled supports which are no longer displaceable in the longitudinal direction of the frame, cf. also  FIG. 23  and  FIG. 24 , since the spacing between the two supports in this instance corresponds exactly to the length of the frame  14 . In order for the frame  14  in this instance to be moved to the envisaged position between the two supports  12 , the bolts  42  must not protrude beyond the end sides of the frame  14  since the frame could otherwise not be placed between the two supports  12 . 
     In order for such a retraction function to be implemented, a housing  110  which is fixed relative to the frame  14  is provided in the case of the connector  104 . An adapter  112  is received so as to be displaceable in the longitudinal direction in the housing  110 , the bolts  42  as well as the tension lock  68  and the safety pin  44  being fastened to said adapter  112 . 
     The illustration of  FIG. 12  shows the connector  104  and the frame  14  in a secured position. The adapter  112  in said secured position is placed relative to the housing  110  such that the bolts  42  extend so far beyond the end side of the frame  14 , cf.  FIG. 13 , that the grooves  14  and the undercuts formed by the grooves also still lie in front of the end side of the frame  14 . The hooks  70  of the tension lock  68  also protrude beyond the end side of the frame  14  and, on account thereof, can engage behind the undercut of the groove  26  of a support  12 , cf.  FIG. 26 . The safety pin  44  is located in the secured position thereof, in which the upper side  45  of said safety pin  44  protrudes beyond the front side of the bolts  42  and on account thereof stops at the upper delimitation of the safety bore  46 , cf.  FIG. 26 . On account thereof, the bolts  42  in said secured position are fixed relative to the keyhole-shaped through openings  24  such that the grooves  41  are disposed in the respective narrower portions  28  of the keyhole-shaped through openings  24 . The safety pin  44  herein is received so as to be displaceable in the adapter  112 . The adapter  112 , by means of the adjustment screw  38  (not visible in  FIG. 13 ) of the safety bolt  44 , can be fixed relative to the housing  110  and thus also relative to the frame  14 . 
       FIG. 14  shows the connector  104  and the frame  14  in an assembly position of the safety pin  44 , and  FIG. 15  shows a side view of the connector  104  and the frame  14  in the assembly position. 
     As can be seen in  FIG. 15 , the bolts  42  by way of the front end thereof protrude beyond the end side of the frame  14  and are located in the same position as has already been shown and explained by means of  FIGS. 12 and 13 . By contrast, the safety pin  44  relative to the adapter  112  has been displaced to the rear so far that only a face of the step-shaped detent  43  still protrudes beyond the front end of the bolts  42 , said face being disposed so as to be parallel with the displacement direction of the safety pin  44 , thus so as to be horizontal in the assembled state of the frame  14 . The frame  14  in this position can be displaced so far upward relative to the support  12 , cf.  FIG. 26 , until the horizontal face of the step-shaped detent  43  stops at the upper delimitation of the safety bore  46  and, on account thereof, simultaneously aligns the front ends of the bolts  42  so as to be in line with the wider portions  26  of the keyhole-shaped through openings  30 . 
     It is to be established by means of  FIG. 15  that the eccentric screw  114  which is accessible by way of the bush  52  and by way of which the hooks  70  of the tension lock  68  can be displaced in and counter to the longitudinal direction of the frame  14  is located in the position at the left end of an elongate hole  116 . By means of the eccentric screw  114 , especially by way of a socket wrench which engages in the eccentric screw  114 , the adapter  112  can be displaced such that the latter in  FIG. 15  is moved to the right until the tool plugged into the eccentric screw  114  stops at the right end of the elongate hole  116 . This retracted position of the adapter  112  is illustrated in  FIGS. 16 and 17 . 
     By way of a comparison of  FIGS. 14 and 16 , or  15  and  17 , respectively, it can immediately be seen that the adapter  112  has now been displaced into the frame  14  so far that no part of the connector  114  protrudes any longer beyond the end side of the frame  14 . In order for this retraction of the adapter  112  to be effected, a tool plugged into the eccentric screw  114  has been displaced relative to the frame so far until the tool stops at the right end in  FIG. 17 , thus the end that is remote from the end side, of the elongate hole  116 , as has already been explained. The frame  14  in this position can be readily pushed between two already fixedly disposed supports, even when the spacing between the two supports corresponds exactly to the length of the frame  14 , cf. also  FIG. 23  and  FIG. 24 . 
     The illustration of  FIG. 18  shows a front view of the connector  104  in the assembled state in the frame  14 . The adapter  112  is configured as a profile and has four receptacle ducts for screwing-in the bolts  42 , a central receptacle chamber for the tension lock  68 , a receptacle duct for the safety pin  44 , and opposite the receptacle duct for the safety pin  44  a screw-in potential for the guide pin  56 . The adapter  112  has an H-type shape, since the receptacle ducts for the bolts  42  are located at the end of webs which extend away from a central part of the adapter  112  which contains the receptacle chamber for the tension lock  68 . The receptacle duct for the safety pin is formed by an approximately C-shaped protrusion which extends from the central part having the receptacle chamber for the tension lock  68 . The receptacle duct for the safety pin  44  is disposed between two receptacle ducts for in each case one bolt  42 . The receptacle, or the receptacle duct, respectively, for the optionally provided guide pin  56  is also disposed between two receptacle ducts for in each case one bolt  42 . 
     On account of the receptacle ducts for the bolts  42  being disposed at the free end of the webs  118 , said receptacle ducts which have a circular-cylindrical external wall can be enclosed across an angle of approximately 300° by a matching guide duct  120  in the housing  110 . The receptacle duct for the bolts  42  on the adapter  112  is thus received so as to be longitudinally displaceable in the guide duct  120  of the housing  110 . For example, a total of four such guide ducts  120  are provided in the housing  110  such that the adapter  112  is mounted in the housing  110  so as to be only displaceable in the longitudinal direction, thus out of the drawing plane and into the drawing plane in the illustration of  FIG. 18 . The housing  110  in this instance is fixed so as to be immovable relative to the frame  14 , as has already been explained. 
     The illustration of  FIG. 19  shows the connector  104  of  FIG. 11  in an enlarged illustration. The four guide ducts  120  on the housing  110  can be seen in this view, said four guide ducts  120  in each case forming the corners of the housing  110 . Each of the guide ducts  120  at the end thereof opposite the bolt  42  is in each case closed by way of a plug  122 . 
     It can be seen in the partially sectioned illustration of the connector  104  in  FIG. 20  that one compression spring  126  is in each case provided between the plug  120  and the receptacle ducts  124  for the bolts  42  on the adapter  112 . The adapter  112  by means of the compression springs  126  is thus pretensioned in a direction away from the plugs  120 . A detent herein is guaranteed by the adjustment screw  38  which stops at the front end of the elongate hole  128  in the housing  110 . 
     As has already been described by means of  FIGS. 15 and 17 , the adapter  112  can be retracted relative to the housing  110 , thus in the direction toward the plugs  122 , in that a tool is plugged into the eccentric screw  114  of the tension lock  68  and said tool is then moved in the direction toward the plugs  122 . 
     The illustration of  FIG. 21  shows a front view of the connector  104 . 
       FIG. 22  shows a plan view of the connecter  104  sectioned along the line A-A in  FIG. 21 . 
     The illustration of  FIG. 23  shows a framework  10  in an L-shape in a view from obliquely below, said framework  10  being composed of a total of eight vertically disposed supports  12  and a total of fifteen horizontally disposed frames  14 . 
       FIG. 24  shows a side view of the framework  10  of  FIG. 23 . The frames  14  at the respective end sides thereof are connected to lateral faces of the supports  12 . These connections are in each case implemented by way of one of the connectors  34 ,  104 . As has already been explained, the connector  34  can be used when there is sufficient space for displacing the frame  14  in the horizontal direction relative to the support. The connector  104  is used when the spacing between the two already fixed and immovable supports corresponds exactly to the length of the frame  14 . 
     All frames  14 , with the exception of the frames  14   a  of which a total of four pieces are provided on the framework  10 , are configured in an identical manner in as far as said frames  14  are formed from the same tubular hollow profile which has already been illustrated and explained in  FIG. 1 . By contrast, the frames  14   a  have double the cross section of the other frames  14 , wherein the internal cross section of the section is also twice present. Consequently, the frames  14   a  are formed in a simplified manner in that two of the hollow profiles for the frames  14  are placed on top of one another and are connected to one another in the region of the bearing face thereof. The frames  14   a  are therefore of a different configuration since the length of the frames  14   a  corresponds substantially to the length of the connectors  34 ,  104 . In order for the supports  12  to be able to be connected at such a small mutual spacing, two connectors  34 ,  104  therefore have to be disposed in the frames  14   a  so as to be offset in the height direction. The connection principle when connecting the frames  14   a  to the connectors  34 ,  104  is however unchanged in relation to that of the frames  14 . 
     The illustration of  FIG. 25  shows in an exemplary manner a support  12  and a frame  14  from the framework  10  of  FIGS. 23 and 24  that is connected in an orthogonal manner to said support  12 . Groups of a plurality of keyhole-shaped through openings  24  which serve for hooking the bolts  42  of the connectors  34 ,  104  can in each case be seen. The groups can in each case have 2, 4, 6, or 8 through openings  24 . 
     It has indeed already been explained by means of  FIG. 26  which illustrates an enlarged portion in the connection region of the support  12  and of the frame  14 , how the connectors  34 ,  104  are inserted into the keyhole-shaped through openings  24  and are then displaced in order for a secure connection between the frame  14  and the support  12  to be established. In the case of the supports  12 , the central axes  32  of the keyhole-shaped through openings  24  are aligned so as to be parallel with the longitudinal direction and thus also parallel with the grooves  26 . 
     The illustration of  FIG. 27  shows an illustration of a portion of the frame  14 . The keyhole-shaped through openings  24  in the case of the frames  14  are aligned such that the central axis  32  of said through openings  24  is disposed so as to be perpendicular to the longitudinal direction of the frame  14  and thus also perpendicular to the groove  26  in the frame  14 . On account thereof, a first frame  14  can be connected in a perpendicular manner to a further frame  14 , if required. 
       FIG. 28  shows a further illustration of a portion of the frame  14 , wherein a cable conduit opening  22  which serves for routing cables in or out is disposed in this portion. 
       FIG. 29  shows a plan view of the support  12  and the frame  14  of  FIG. 25 . 
       FIG. 30  shows a connector  140  according to a further embodiment of the invention from obliquely above. The connector  140  in principle is configured so as to be very similar to the connector  34  of  FIG. 1 , but is provided as a double-sided connector. The connector  140  is specially provided for connecting to one another two supports  12  or frames  14  that are disposed so as to be very close to one another, for example the corner support  12  of  FIG. 24  to the adjacent support  12 . The connector  140  herein is pushed into a frame  14  which is as long as the frame  14   a  illustrated in  FIG. 24 , but is of only half the height. 
     The connector  140  at the front and rear end face thereof is in each case provide with 4 bolts  42  which have in each case one undercut. As described, the bolts  42  are in each case hooked into a keyhole-shaped through opening  24  in the supports  12 , or the frames  14 , respectively. 
     Moreover, one tension lock  68  is in each case provided on the front end side and the rear end side of the connector  140 , cf. also  FIG. 31 . Moreover, one safety bolt  142  which by means of in each case one assigned adjustment screw  38  can be advanced or retracted is in each case provided on the front and rear end side of the connector  140 . The function of the double-sided connector  140  of  FIGS. 30 and 31  corresponds to the function of the connector  34  of  FIG. 1  and is not explained again. In order for two supports  12  or frames  14  to be connected at a spacing which corresponds to the spacing between the undercut grooves  41  of the bolts  42  at the front end face and the undercut grooves  41  of the bolts  42  at the rear end face of the connector  140 , the connector is pushed into a frame  14  or a support  12 , the length of said frame  14  or said support  12  corresponding to the length of the housing  50  of the connector  140 . The bolts  42  are then in each case hooked into a keyhole-shaped through opening. The tension locks  68  in this case serve for additionally bracing the supports  12  or frames  14 , respectively, that are disposed at a mutual spacing. The connection can then be secured in a form-fitting manner against unintentional releasing by advancing the safety bolt  142 .