Abstract:
The invention relates to a device comprising a profiled rail ( 10 ) and at least one fastening element ( 12 ) for fixing a machine tool and/or a workpiece to the profiled rail ( 10 ). The fastening element ( 12 ) is provided with at least one clamping jaw ( 22, 24 ) and a clamping means ( 26 ) that is effectively connected to the clamping jaw ( 22 ) in order to brace the clamping jaw ( 22 ) with the profiled rail ( 10 ). According to the invention, the clamping means ( 26 ) is embodied as an eccentric lever.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The invention described and claimed hereinbelow is also described in German Patent Application DE 10 2005 050 783.2 filed on Oct. 24, 2005. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a device with a profiled rod and at least one fastening element. 
     Publication US 2004/0221923 A1 makes known a device with a profiled rail and two fastening elements for mounting a machine tool and/or a work piece on the profiled rail. Each of the fastening elements includes two clamping jaws, and a first clamping jaw is operatively connected with a spring. The spring serves as clamping means for clamping the clamping jaw onto the profiled rail. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a device with a profiled rail and at least one fastening element of a machine tool and/or a work piece on the profiled rail. The fastening element is provided to grip the sides of the profiled rail; it includes at least one clamping jaw and clamping means operatively connected with the clamping jaw for clamping the clamping jaw onto the profiled rail. 
     It is provided that the clamping means are designed as an eccentric lever. 
     By using leverage to produce a clamping force, a stable hold with a strong clamping force can be attained in a comfortable manner and, in particular, without the use of tools. Advantageously, the fastening element can be prevented from accidentally becoming detached from the profiled rail, which can be dangerous, and which can occur, e.g., with clamped connections produced by spring force. Safety risks can therefore be eliminated when mounting machine tools, in particular, such as circular saws, cross saws or mitre saws. 
     The eccentric lever can include an eccentric cam or a pin or bolt that is positioned eccentrically relative to a fixed swivel axis of the eccentric lever. 
     A particularly secure hold can be attained when the clamping means are provided to fix the clamping jaw in a clamped position in a form-fit manner. In this context, the term “provided” should be understood to also mean “designed” and “equipped”. The clamped position of the clamping jaw is characterized, in particular, by a clamping surface of the clamping jaw bearing against a corresponding mounting surface of the profiled rail with a contact force or clamping force. 
     A particularly robust fastening element is obtainable when the clamping means are supported in the fastening element such that they are displaceable along a straight line. Highly stressed pivot axes can be prevented in particular. 
     When a maximum displacement travel of the clamping means is at least so great that the fastening element can be lifted off of the profiled rail when the clamping means are in a released position, the fastening means or machine tool can be connected with the profiled rail in a particularly rapid and convenient manner. 
     A particularly dust-resistant fastening device as can be attained using simple design means when the operative connection between the clamping jaw and the clamping means is produced by an eccentric cam integrally formed on the clamping means. 
     In an alternative embodiment of the present invention, the operative connection between the clamping jaw and the clamping means is produced by a connecting rod that is connected eccentrically with the clamping means. As a result, a transfer of force via a body of the fastening element can be prevented. 
     When the device includes safety locking means for securing the clamping jaw in a clamped position, the clamping means can be effectively prevented from becoming accidentally released. 
     When the safety locking means automatically engage in the clamping means when the clamped position is reached, it can be ensured that the device cannot be used without actuating the safety locking means. In particular, when the clamping jaw is fixed in its clamped position by the clamping means in a form-fit manner, the leverage of the clamping means can improve the effect of the safety locking means, and, in fact, compared with embodiments of the present invention with which the safety locking means engage in the clamping jaw directly. 
     In an alternative embodiment of the present invention, the safety locking means engage in the connecting rod. 
     When the device includes a second clamping jaw with a clamping surface designed as mirror image—relative to a plane of symmetry of the profiled rail—of a clamping surface of the first clamping jaw, it is possible to choose any orientation of the fastening element relative to the profiled rail. As a result, the device can be adapted to various applications in a more flexible manner. In addition, asymmetric wear can be prevented. 
     A particularly large variety of machine tools and/or work pieces can be mounted on the profiled rail using the fastening element when the device includes at least one threaded plate that is displaceable relative to a frame of the fastening element. By displacing the threaded plate, the fastening element can be adapted to various hole patterns in the machine tool and/or the work piece without the need to create additional holes. 
     Particularly easy installation of the fastening element on the machine tool and/or the work piece can be attained when the displaceable threaded plate is accessible from both sides of the frame of the fastening element, and/or when the frame includes an engagement recess in the region of the displaceable threaded plate. The device can form a complete, portable work bench when the profiled rail is equipped with collapsible support legs. User comfort can be enhanced further when the profiled rail is equipped with a handle. 
     When the profiled rail includes a holding device for holding a screw tool, transport and set-up of the device, e.g., at a work site, can be simplified. 
     When the profiled rail includes a fastening groove for mounting a machine tool and/or a work piece, the spectrum of applications for the profiled rail can be expanded. 
     Transport can be made even more comfortable when the profiled rail is equipped with a handle. 
     Further advantages result from the description of the drawing, below. Exemplary embodiments of the present invention are shown in the drawing. The drawing, the description and the claims contain numerous features in combination. One skilled in the art will also advantageously consider the features individually and combine them to form further reasonable combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a portable work bench with a profiled rail and two fastening elements, 
         FIG. 2  shows one of the fastening elements in  FIG. 1 , 
         FIG. 3  shows the fastening element in  FIG. 2 , in a view diagonally from below, 
         FIG. 4  shows clamping means of the fastening element and safety locking means, in a detailed view, 
         FIG. 5  shows a handle of the profiled rail in  FIG. 1 , 
         FIG. 6  shows the profiled rail, the fastening element, and clamping means in a clamped position, 
         FIG. 7  shows the profiled rail, the fastening element, and clamping means in a released position, 
         FIG. 8  shows a profiled rail and an alternative fastening element, in a clamped 
         FIG. 9  shows the profiled rail and the fastening element in  FIG. 8  in a released position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a portable work bench with a profiled rail  10   a  made of aluminium, which is equipped with collapsible support legs  14   a - 14   a ′″, two extensions  16   a ,  16   a ′, and a handle  18   a . Extension  16   a  can be slid into profiled rail  10   a , and support legs  14   a - 14   a ′″ can be folded inward, thereby enabling the work bench to be transported as a compact unit. One of the support legs  14   a  is designed to be height-adjustable, in order to attain good stability on uneven ground. 
     Portable work bench includes two fastening elements  12   a ,  12   a ′, which can be clamped onto profiled rail  10   a . Any type of machine tool, particularly electrical machine tools, and work pieces can be screwed onto fastening elements  12   a ,  12   a ′, or they can be connected with fastening elements  12   a ,  12   a ′ in any other manner deemed suitable by one skilled in the art. The machine tool or the work piece can then be connected with profiled rail  10   a  comfortably and rapidly using fastening elements  12   a ,  12   a′.    
     Fastening element  12   a  includes—on its underside  20   a  facing profiled rail  10   a —a first, movable clamping jaw  22   a  and a second, fixed clamping jaw  24   a . Clamping means  26   a  operatively connected with first, movable clamping jaw  22   a  are located at one end of longitudinal fastening element  12   a  and are designed as a pivotable eccentric lever capable of pivoting around a pivot axis  32   a  extending parallel to a longitudinal axis  28   a  of profiled rail  10   a.    
     A top side  34   a  of fastening element  12   a  that faces away from profiled rail  10   a  when in the installed state includes a first threaded plate  36   a  capable of being displaced along longitudinal axis  30   a  of fastening element  12   a  and along longitudinal axis  28   a  of profiled rail  10   a , and a second threaded plate  38   a , which is fixed in position relative to a frame  40   a  of fastening element  12   a  ( FIG. 2 ). Displaceable threaded plate  36   a  is connected via a slot  76   a  and a bolt  78   a  engaged in slot  76   a  with frame  40   a , and has a T-shaped design overall ( FIG. 3 ). The ends of the crossbar of the T shape extend laterally through slits  80   a ,  80   a ′ in frame  40   a . As a result, the mobility of threaded plate  36   a  relative to a swivel motion around bolt  78   a  is limited by the ends of slits  80   a ,  80   a ′. The amount of play that threaded plate  36   a  has in the direction of longitudinal axis  30   a  of fastening element  12   a  is limited by the length of slot  76   a . The machine tool or work piece to be mounted can be screwed together with both threaded plates  36   a ,  38   a  via bore holes. The user can thereby adapt the position of first, displaceable threaded plate  36   a  to a hole pattern of the machine tool or the work piece. Due to the threads provided in threaded plates  36   a ,  38   a , bolts—which could easily become lost—need not be used when screwing the machine tool into place. In a cutting plane extending transversely to a longitudinal axis  30   a  of fastening element  12   a , the latter has a U-shaped profile that opens downward in the direction toward profiled rail  10   a , thereby enabling threaded plates  36   a ,  38   a  located in the region of top side  34   a  of fastening element  12   a  to be accessed freely from below to screw the machine tool or the work piece into place. 
     First clamping jaw  22   a  is supported in fastening element  12   a  such that it can be displaced along a straight line, and it is connected with clamping means  26   a  via a connecting rod  42   a . Connecting rod  42   a  is connected with clamping means  26   a  via a bolt such that it can pivot around pivot axis  32   a . Clamping means  26   a  include an eccentric cam  66   a , which bears against a support tab  74   a  of frame  40   a , thereby enabling a swiveling motion of clamping means  26   a  to be transferred—by eccentric cam  66   a  gliding over support tab  74   a —into a reciprocating motion of connecting rod  42   a  and clamping jaw  22   a  connected via a connecting bolt with connecting rod  42   a  ( FIGS. 6 and 7 ). A return spring  68   a  automatically returns clamping jaw  22   a  from an intermediate position to the opened position and, in the opened position, it generates a contact force of eccentric cam  66   a  on support tab  74   a . To attain horizontal guidance and a vertical hold of connecting rod  42   a , the latter is guided through a hole—which is not shown explicitly here—in support tab  74   a.    
     Clamping jaws  22   a ,  24   a  include clamping surfaces  44   a ,  46   a  designed as mirror images of each other, which bear against fastening ridges  48   a ,  50   a  of profiled rail  10   a  in a clamped position ( FIG. 6 ). Clamping surfaces  44   a ,  46   a  grip partially around fastening ridges  48   a ,  50   a , so that fastening element  12   a —when in the clamped position—is connected in a form-fit manner with profiled rail  10   a  in a vertical direction and in a direction that extends perpendicularly to longitudinal axis  28   a  of profiled rail  10   a  and to longitudinal axis  30   a  of fastening elements  12   a . A width  72   a  ( FIG. 3 ) of clamping surfaces  44   a ,  46   a  along longitudinal axis  28   a  of profiled rail  10   a  is a few centimeters, particularly more than three centimeters, so that clamping jaws  22   a ,  24   a  automatically become oriented at a right angle with profiled rail  10   a  when they are clamped thereon. Given that a length  52   a  of first, movable clamping jaw  22   a  is greater than width  72   a  of clamping surface  44   a ,  46   a  and, in particular, is greater than five centimeters, clamping jaw  22   a  can be effectively prevented from tilting within frame  40   a  of fastening element  12   a  via a large mounting surface, thereby ensuring parallelism between clamping jaw  22   a  and fastening element  12   a , and therefore ensuring that a right angle is formed between longitudinal axis  28   a  of profiled rail  10   a  and longitudinal axis  30   a  of fastening element  12   a  in the clamped state. 
     Safety locking means  54   a  with an integrally formed pin  56   a , which are spring-loaded, rod-shaped, and displaceable parallel to longitudinal axis  28   a  of profiled rail  10   a , are located in the region of clamping means  26   a , and they automatically engage in clamping means  26   a  when clamping means  26   a  reach the clamped position ( FIG. 4 ). 
     Shortly before the clamped position is reached, the reciprocating motion of connecting rod  42   a  passes an apex, so that clamping means  26   a  fix clamping jaw  22   a  in the clamped position in a form-fit manner. In the clamped position, a bore hole in clamping means  26   a  overlaps a pin  56   a  of safety locking means  54   a , so that the latter automatically snaps into place and engages in clamping means  26   a . To release clamping means  26   a , a user can push safety locking means  54   a  back against the force of a spring by pressing on an end  58   a  of safety locking means  54 , thereby allowing clamping means  26   a  to be released. 
     In an alternative embodiment of the present invention, the safety locking means engage in connecting rod  42   a.    
     In a released configuration, in which clamping surfaces  44   a ,  46   a  are further away from each other—by displacement travel  70   a  (FIG.  7 )—than in the clamped position, a distance between clamping surfaces  44   a ,  46   a  is at a maximum and exceeds a maximum width  60   a  between fastening ridges  48   a ,  50   a  of profiled rail  10   a , thereby enabling the machine tool and/or work piece to be lifted—together with fastening elements  12   a ,  12   a ′—in a vertical direction off of profiled rail  10   a . Similarly, the machine tool and/or work piece can be placed on profiled rail  10   a  in the vertical direction when clamping means  26   a  are released. 
       FIG. 5  shows a handle  18   a , which is screwed onto profiled rail  10   a  from below. Handle  18   a  is designed as a plastic, injection-molded part, and simultaneously serves as a retaining means for holding a screw tool  62   a , i.e., an Allen wrench. On a top side that extends horizontally in the installed state, profiled rail  10   a  includes a fastening groove  64   a  for fastening machine tools with appropriate clamp-connection means. Fastening groove  64   a  can be used as an alternative to fastening elements  12   a ,  12   a′.    
       FIGS. 8 and 9  show an alternative embodiment of the present invention. The description mainly addresses the differences between the exemplary embodiments shown in  FIGS. 1 through 7 . Similar features are labeled with the same reference numerals. To distinguish the exemplary embodiments from each other, the reference numerals are appended with the letters “a” and “b”. 
     An operative connection that exists between clamping means  26   b  and a first, movable clamping jaw  22   b  is generated by an eccentric cam  66   b  integrally formed on clamping means  26   b ; eccentric cam  66   b  glides along a corresponding mounting surface of clamping jaw  22   b . For clamping, clamping jaw  22   b  is pressed onto a profiled rail  10   b  in the longitudinal direction of a fastening element  12   b  ( FIG. 8 ). When clamping means  26   b  are released, a return spring  68   b  moves clamping jaw  22   b  away from profiled rail  10   b , so that fastening element  12   b  can be lifted off of profiled rail  10   b  along with the machine tool screwed in place thereon.