Abstract:
A guide rail of a linear guide, on guide surfaces on which a guide carriage is longitudinally displaceable. A material measure is arranged at a distance, preferably in parallel, to the guide rail and is fastened to the guide rail by means of a mount. The guide rail has a groove or a hole arranged outside the guide surface. The mount can be detachably fastened by means of expanding elements that engage with the groove or into the hole.

Description:
This application is a 371 of PCT/EP2007/063793 filed Dec. 12, 2007, which in turn claims the priority of DE 10 2007 003 647.9 filed Jan. 25, 2007, and DE 10 2007 009 461.4 filed Feb. 27, 2007 the priority of these applications is hereby claimed and these applications are incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The present invention relates to a guide rail of a linear guide, on the guide surfaces of which a guide carriage can be mounted so as to be longitudinally displaceable. 
     BACKGROUND OF THE INVENTION 
     Linear guides are often provided with a length measuring device so that a guide carriage guided longitudinally displaceably on the guide rail can be positioned satisfactorily by suitable drive and control means. DE 102 14 426 A1, for example, discloses a guide rail. The material measure arranged laterally next to the guide rail is held on the guide rail via a holder. The holder provides two approximately u-shaped brackets which are fastened in each case to one end of the material measure and which surround the guide rail. The u-shaped holding brackets, surrounding the guide rail, are braced with the latter, and the guide surfaces of the guide rail act as tension surfaces to releasably fasten the holding brackets. One disadvantage of a holder of this type may be seen in that a further guide carriage which is arranged on the guide rail is limited in its longitudinal displaceability by the arrangement of the two holding brackets which surround the guide rail. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to specify a guide rail, in which the disadvantage indicated above is avoided. 
     The object is achieved, according to the invention, by the guide rail which has, a plurality of guide carriages that can be moved one behind the other along the guide rail, without a collision or impact of the further guide carriage with the holder of the material measure occurring. The holder is fastened releasably at locations on the guide rail which lie outside the guide surfaces of the guide rail. The shape of the holder itself may be such that it lies outside a clearance profile of the guide carriage. The groove walls or the wall delimiting the hole are preferably oriented perfectly at right angles to the longitudinal axis of the guide rail. When the spreading means, formed, for example, by wedges, come to bear closely, while spreading open, against the groove walls or the wall of the hole, a perfect orientation of the holder of the guide rail can thus be assisted. 
     The holder may have a holding arm on which the material measure is held, the holding arm having a supporting surface, arranged along the guide rail, for supporting the holding arm on the guide rail. This supporting surface is preferably arranged perfectly parallel to the longitudinal axis of the material measure. The holding arm is supported and mounted with its supporting surface on a bearing surface of the guide rail. The bearing surface of the guide rail is oriented perfectly parallel to the longitudinal axis of the guide rail as a consequence of production. If, then, the holder is mounted with the holding arm, the supporting surface of the holding arm is oriented perfectly with respect to the bearing surface of the guide rail, the perfect orientation not being disturbed even after the bracing and spreading open of the spreading means. 
     Since the holder is preferably arranged outside the clearance profile of the guide carriage, there may be provision, for a sufficient extent of the supporting surface, for the latter to be formed on an angled part of the holding arm. This angled part can then be oriented parallel to the longitudinal axis of the guide rail. 
     In a particular exemplary embodiment for the releasable fastening of the holder on the guide rail, the spreading means have cooperating wedges, one of which is arranged fixedly to the holding arm and another of which is arranged moveably with respect to the one wedge. The wedges cooperate such that they come to bear in the groove against the groove walls of the latter and are pressed onto these. The wedges can bear with their mutually confronting wedge surfaces one against the other and can be braced with one another in the groove of the guide rail via a tension screw. By the tension screw being turned, the two wedges are displaced along their wedge surfaces and come to bear with their tension surfaces against groove walls of the groove. The one wedge may in this case be connected in one piece to the holding arm. The tension surfaces, facing away from one another, of the wedges are preferably arranged at right angles to the supporting surface of the holding arm, so that a satisfactory positioning of the holder and therefore for satisfactory positioning of the material measure with respect to the guide rail are possible. 
     The wedge assigned to the holding arm may also be designed as a double wedge which has two wedge legs which are arranged spaced apart, and which has mutually confronting wedge surfaces and tension surfaces, facing away from one another, for bearing against the two groove walls of the transverse groove. A moveable wedge engages between the two wedge legs which wedge can be pressed with its wedge surfaces against the wedge surfaces of the double wedge. For tensioning, a tension screw can be used which displaces the moveable wedge along the wedge surfaces by means of screwing movements. 
     For the simple introduction of the wedges, the groove in the foot region of the guide rail may advantageously be designed as a transverse groove arranged transversely with respect to the longitudinal axis of the guide rail. The wedges can consequently be inserted into the open transverse groove from below in a simple way. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained in more detail below with reference to three exemplary embodiments depicted in a total of seven figures in which: 
         FIG. 1  shows a guide rail according to the invention with a mounted guide carriage in a perspective illustration; 
         FIG. 2  shows a detail from  FIG. 1 ; 
         FIG. 3  shows a further detail from  FIG. 1 ; 
         FIG. 4  shows an enlargement of a detail from  FIG. 3 ; 
         FIG. 5  shows a further fastening according to the invention of a holder; 
         FIG. 6  shows a further guide rail according to the invention in a partially exploded illustration; and 
         FIG. 7  shows the guide rail from  FIG. 6 , as seen from the underside. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A guide rail according to the invention is depicted in  FIGS. 1 to 4 .  FIG. 1  shows the guide rail  1  with a mounted guide carriage  2 . The guide carriage  2  is guided and mounted on guide surfaces  1   a  of the guide rail  1 . Furthermore, a material measure  3  is provided, which is fastened releasably to the guide rail  1  via holders  4 . Only one holder  4  is depicted in  FIG. 1 . 
     It can be gathered from  FIG. 1  that a measuring head  5  is attached to the guide carriage  2 , the measuring head  5  cooperating in a known manner with the material measure  3  so that predetermined positions on the guide rail can be moved up to in a controlled way. 
       FIG. 2  shows an enlargement of a detail from  FIG. 1 , in which, in particular, the holder  4  can be seen clearly. The holder  4  has a holding arm  6 , the lower part of which is angled. A retainer  7  is placed onto the holding arm  6  and carries the material measure  3 . The retainer  7  may also be formed in one piece with the holding arm  6 . The holder  4  is dimensioned such that it is arranged outside the clearance profile of the guide carriage  2 . Even if a further guide carriage is arranged on the guide rail  1 , the risk of collision with the holder  4  is consequently ruled out. 
     The holding arm  6  is provided with a supporting surface  8  which is arranged along the guide rail  1  and by means of which the holding arm  6  is supported on a foot surface  9  of the guide rail  1 . This foot surface  9  consequently also forms a bearing surface for the holder  4 . The supporting surface  8  is arranged axially parallel to the material measure  3 . The foot surface  9  of the guide rail  1  is likewise arranged axially parallel to the material measure  3  and outside the guide surfaces  1   a.    
       FIG. 3  shows the same detail as  FIG. 2 , but from the underside of the guide rail  1 . It can be seen here that the guide rail  1  is provided in the foot region with a groove  10  which in the present case is designed as a transverse groove  11 . This transverse groove  11 , which is open to the foot side of the guide rail  1 , is delimited by two groove walls  12  arranged parallel to one another, these groove walls  12  being arranged transversely with respect to the longitudinal axis of the guide rail  1 . These groove walls  12  are arranged perfectly transversely with respect to the supporting surface  8  of the holder  4 . 
     It can be gathered from  FIG. 3  that a wedge  13  formed in one piece with the holding arm  6  engages into the transverse groove  11 . A further wedge  14  is provided which is likewise arranged in the transverse groove  11 , the two wedges  13 ,  14  bearing mutually confronting wedge surfaces  15 ,  16  one against the other, the two wedges  13 ,  14  being braced with respect to one another in the transverse groove  11  via a tension screw  17 . The wedges  13 ,  14  are arranged so as to be movable along the wedge surfaces  15 ,  16  in order to set the intended bracing tension. The two wedges  13 ,  14  are both provided with tension surfaces  18 ,  19  which are arranged perfectly parallel to the groove walls  12  of the transverse groove  11 . 
     It is clear from  FIG. 4  how the two wedges  14 ,  15  cooperate with the tension screw  17  in order to allow bracing in the transverse groove  11 . The wedge  15  is provided with a passage bore  20  and the wedge  14  with a threaded bore  21  aligned with this. The tension screw  17  is led through the passage bore  20  and engages with its external thread into the internal thread of the threaded bore  21 . The diameter of the passage bore  20  is dimensioned such that the threaded shaft of the tension screw  17  has sufficient radial play to allow the displacement of the two wedges  13 ,  14  with respect to one another. By the tension screw being actuated, the wedge  14  is drawn towards the wedge  15 , a parallel displacement of the two tension surfaces  18 ,  19  of the two wedges  14 ,  15  being generated. Finally, the two wedges  14 ,  15  come to bear with their tension surfaces  18 ,  19  against the groove walls  12  and bear closely there. A non-positive connection of the holder  4  to the guide rail  1  is then ensured. 
       FIG. 5  shows a detail of a further guide rail  22  according to the invention with a modified fastening of a holder  23 , which differs from the exemplary embodiment described above essentially in that, instead of spreading means or wedges, merely one or more fastening screws  24  are provided which are screwed into matching threaded bores  25  on the guide rail  22 . The threaded bore  25  is formed within a foot surface  26  of the guide rail  22 . A holding arm  27  of the holder  23  is provided on its angled part with a supporting surface  28  which bears against the foot surface  26  of the guide rail  22 . The holding arm  27  is provided with a passage bore  29  through which the fastening screw  24  is led. The angled part of the holding arm  27  is clamped between the screw head of the fastening screw  14  and the guide rail  22 . 
       FIGS. 6 and 7  show the guide rail  1  according to the invention, as in  FIG. 1 , with a modified holder  29 . The holder  29  has a holding arm  30  on which the material measure  3  is held. A double wedge  31  is formed in one piece with the holding arm  30 . The double wedge  31  comprises two wedge legs  32  arranged spaced apart from one another. The wedge legs  32  have mutually confronting wedge surfaces  33  and tension surfaces  34  facing away from one another. 
     The two wedge legs  32  delimit a v-shaped orifice into which a movable wedge  35  engages. The double wedge  31  is adapted to the transverse groove  11  and bears with its parallel tension surfaces  34  against the groove walls  12  of the transverse groove  11 . 
     The double wedge  31  is provided with a passage bore  36  and the movable wedge  35  is provided with a threaded bore  37 . A tension screw  38  is led through the passage bore  36  and engages into the threaded bore  37 . By the tension screw  38  being tightened, the wedge  35  is drawn into the v-shaped orifice of the double wedge  31  until the wedge surfaces  39  of the wedge  35  butt against the wedge surfaces  33  of the wedge legs  32 . Under a wedging action of the wedge  35 , the wedge legs  32  are spread apart, the tension surfaces  34  being pressed against the groove walls  12  of the transverse groove  11 . 
     The designs according to the invention, shown in  FIGS. 1 to 4  and  FIGS. 6 and 7 , are suitable particularly for guide rails, the lateral foot surfaces of which are very narrow below the guide surfaces. In these cases, sometimes, there is not sufficient space for forming a threaded bore. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               1  Guide Rail  22  Guide Rail 
               1   a  Guide Surface  22   a  Guide Surface 
               2  Guide Carriage  23  Holder 
               3  Material Measure  24  Fastening Screw 
               4  Holder  25  Threaded Bore 
               5  Measuring Head  26  Foot Surface 
               6  Holding Arm  27  Holding Arm 
               7  Retainer  28  Supporting Surface 
               8  Supporting Surface  29  Holder 
               9  Foot Surface  30  Holding Arm 
               10  Groove  31  Double Wedge 
               11  Transverse Groove  32  Wedge Leg 
               12  Groove Wall  33  Wedge Surface 
               13  Wedge  34  Tension Surface 
               14  Wedge  35  Movable Wedge 
               15  Wedge Surface  36  Passage Bore 
               16  Wedge Surface  37  Threaded Bore 
               17  Tension Screw  38  Tension Screw 
               18  Tension Surface  39  Wedge Surface 
               19  Tension Surface 
               20  Passage Bore 
               21  Threaded Bore