Abstract:
An auxiliary device for processing a flat surface of a workpiece, particularly a plate-like workpiece, includes a ruler-like base rail with at least one guide formed by a profiling of the base rail for slidably connecting a support plate with a recess for exchangeably mounting an electrical processing apparatus. The recess of the support plate has at least one adjustable and lockable stop for the processing apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an auxiliary device for processing a flat surface of a workpiece, particularly a plate-like workpiece. The auxiliary device is composed of a ruler-like base rail with at least one guide formed by a profiling of the base rail for slidably connecting a support plate with a recess for exchangeably mounting an electrical processing apparatus.  
         [0003]     2. Description of the Related Art  
         [0004]     It is known in the art to process the flat surface of a workpiece by means of a routing cutter. It is also known in the art to process a plate-shaped workpiece, which also has a flat surface, by cutting it to size by means of a piercing saw or to cut portions out of the workpiece. Depending on the geometrical shape of processing, it is necessary that the processing device, i.e., the routing cutter or the piercing saw, is guided as precisely as possible. For this purpose, an auxiliary device can be used which is composed of a ruler-like base rail of metal and a support plate with a recess.  
         [0005]     A base rail of the above-described type is known, for example, from published European patent application 1 125 692. The base rail includes a guide which is preferably formed by an appropriate profiling of the base rail. The support plate with the recess is suspended from this guide, wherein this recess is precisely adapted to the shape and the size of the processing apparatus being used, so that the processing apparatus can be received by the recess in a positively locking manner. This means that another processing apparatus, i.e., a routing cutter or a piercing saw, which may be, for example, from another manufacturer and which may have a different shape in the area where it is received, cannot be received by the recess of the support plate. It is necessary to use a different receiving plate for this purpose, wherein the receiving plate has a recess which precisely matches the processing apparatus. If such a receiving plate is not available, it is not possible to provide an exact guide for the processing apparatus, and, thus, an exact processing of the workpiece is not possible. Moreover, using the known base frame, it is only possible to carry out processing extending in a linear direction. Cuts that have a circular arc-shaped pattern can only be achieved by using manual guidance and, therefore, are extremely imprecise.  
       SUMMARY OF THE INVENTION  
       [0006]     Therefore, it is the primary object of the present invention to provide an auxiliary device for processing a flat surface of a workpiece, especially a plate-shaped workpiece, which ensures that different processing apparatus, particularly processing apparatus from different manufacturers, can be precisely received. In addition, it should also be possible to guide the processing apparatus precisely on a predetermined circular line.  
         [0007]     In accordance with the present invention, in an auxiliary device of the above-described type, the recess of the support plate has at least one adjustable and lockable stop for the processing apparatus.  
         [0008]     A stop of the above-described type can be adjusted without great difficulties and within a very short time and, thus, can be adapted to the respective processing apparatus. This makes it possible to use different processing apparatus, particularly from different manufacturers, on the base rail and to guide the apparatus very precisely on the workpiece for achieving the desired processing of the workpiece.  
         [0009]     The various features of novelty, which characterize the invention, are pointed out with particularity in the claims annexed to and forming part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0010]     In the drawing:  
         [0011]     The single FIGURE of the drawing is a top view of an auxiliary device in accordance with the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     The drawing shows an auxiliary device for processing a flat surface of a workpiece, not shown. In the illustrated embodiment, the auxiliary device is used for manufacturing a milling cut or a cut in a plate-shaped workpiece. For carrying out the milling cut, a conventional routing cutter is used and for the cut a commercially available piercing saw is used. In order to achieve a problem-free processing, these processing apparatus must be precisely guided on the upper surface of the workpiece. The auxiliary device is used for this purpose.  
         [0013]     The auxiliary device is composed first of a base rail  1 , preferably of aluminum, which is available on the market in different lengths. The base rail  1 , which is preferably manufactured continuously by an extrusion method and is then cut to the desired length, has in the illustrated embodiment on its upper side two undercut grooves  2 ,  3  which have a T-shaped or dovetail-shaped cross-section. In addition, at the edge of the upper side a measuring scale  4  is provided which begins in an advantageous manner at “zero” at the lower end of the drawing. The base rail  1  may have at its bottom side also at least one groove which, however, is not shown for clarity&#39;s sake and which is also not required for explaining the invention. If necessary, a rib having a triangular cross-section may be provided on the upper side of the base rail  1  so as to extend in the longitudinal direction thereof.  
         [0014]     For guiding the processing apparatus as mentioned above, differently shaped support plates  5 ,  6  are arranged on the base rail  1 , wherein, however, always only one support plate  5  or  6  is used for a processing procedure. These support plates  5 ,  6  are advantageously composed of plastics material. Each of these support plates  5 ,  6  is profiled in its lower area facing the base rail  1  in such a way that the support plate rests with locking engagement at the base rail  1 . If necessary, the bottom side of the support plate  5 ,  6  may also have at least one spring or a projection which ensures a very precise guidance of the support plates  5 ,  6  in the longitudinal direction of the base rail  1 , as indicated by double arrow  7 . In addition, each support plate  5 ,  6  has two continuous bores  8 ,  9  through each of which extends upwardly a screw, not shown, whose head is adapted to the cross-section of the roof  3  and is guided in the groove  3 . These screws then project at the upper side of the support plates  5 ,  6  from the support plates and receive a tightening nut each by means of which the respective support plate  5 ,  6  can be immovably secured in its desired position on the base rail  1 . For adjusting the precise position of the support plates  5 ,  6  on the base rail  1 , each support plate  5 ,  6  has a marking  9  which faces the measuring scale  4 .  
         [0015]     Each support plate  5 ,  6  is provided with a recess  11  which has a rectangular shape in the support plate  5  and a circular shape in the support plate  6 . The recess  11  of the support plate  5  has on two oppositely located sides a stepped edge  12 , while this edge  12  is circular and surrounds the support plate  6 . A stop ledge  13  each is provided on both edges  12  and, thus, on the support plate  5 , wherein both stop ledges can be moved manually from the illustrated position toward each other. For this purpose, schematically illustrated grooves, slots or springs  14  are provided at the bottom side of each stop ledge  13  which, in the illustrated embodiment, extend at an angle of 45° relative to each other and which interact with springs, grooves or slots which are provided on the upper side of the edges  12  and, thus, in the support plate  5 . In addition, an oblong hole  15  also extending at an angle of 45° is worked into each stop ledge  13 , wherein a screw  16  placed in the edges  12  or in the support plate  5  projects through the oblong hole  15 . By means of a nut screwed onto the screws  16 , the stop ledges  13  can be adjusted and secured in their desired positions on the edges  12 . This adjusted position corresponds precisely to the width of the base of a processing device, for example, a piercing saw. Accordingly, by using the two stop ledges  13 , it is possible to receive piercing saws of different sizes, particularly different widths of their base, securely and especially without play on the support plate and to guide the saws on the base rail  1 .  
         [0016]     The means for securing the processing apparatus is constructed somewhat differently in the support plate  6 . In this case, a stop ledge  17  and two stop pieces  18  are provided on the support plate  6  near the edge  12  thereof. The stop ledge  17  as well as the stop pieces  18  each have an oblong hole  19 , wherein all oblong holes extend perpendicularly of the base rail  1 . It is also possible to provide these oblong holes  19  in the support plate  6 . Because of the upper holes  19 , the stop ledge  17  and the two stop pieces  18  can be moved relative to each other and, thus, the base of the processing apparatus, for example, a routing cutter, can be placed without play in the support plate  6  and can be held securely in its position. Accordingly, the stop ledge  17  and the two stop pieces  18  make it possible also in this case to receive processing apparatus with different sizes of their bases. In the respective stop position, the stop ledge and the two stop pieces  18  are secured by means of screws  20  which are placed in the support plate  6  and receive a tightening nut at the ends which protrude through the stop ledge  18  and the stop pieces  19 .  
         [0017]     In the two support plates  5 ,  6  it is possible to manually screw the above-mentioned screws  20  also into threaded bores at the edges  12  of the support plate  5  or the support plate  6 , while the heads of the screws  20  rest from the outside on the stop ledges  13 ,  18  and the stop pieces  19 . Four additional oblong holes  21 , only schematically illustrated, can be provided in the support plate  6 . These oblong holes  21  are used when the processing apparatus, for example, a routing cutter, is to assume a position which is turned by 90° on the support plate  6 . Also, in this position, the processing apparatus is sufficiently secured.  
         [0018]     The auxiliary device described thus far makes only possible a processing of a workpiece, for example, a plate, by moving the processing apparatus along the base rail  1 . Of course, for carrying out this processing, the support plates  5 ,  6  are not clamped to the base rail  1 . However, it may also happen that processing is carried out on the flat surface of the workpiece which extends along a circular line. The auxiliary device according to the present invention can also be used in that case. At the lower end of the base rail  1  as seen in the drawing, the illustrated embodiment has an intermediate plate  22  which, as is the case in the two support plates  5 ,  6  described above, is slidably guided in the direction of double arrow  23  on the base rail  1  and can be secured to the base rail  1  by means of screws  8 .  
         [0019]     Normally, the intermediate plate  22  assumes the zero position at the measuring scale  4  as shown in the drawing. In this embodiment, the intermediate plate  22  has a bore  24  through which a screw, not shown, projects. This screw is guided in the groove  3  of the base rail  1  with its head so as to be prevented from rotating, and receives a tightening screw, not shown, on its portion which protrudes out of the intermediate plate  22 . A bearing body  25  can be clamped to the intermediate plate  22  by means of the tightening nut, wherein the bearing body  25  is slidably guided on the intermediate plate  22  in the direction of double arrow  26  and, thus, perpendicularly of the base rail  1 . The length of this displacement is limited by an oblong hole  27  in which a bearing body  25  has been placed and through which the screw, not shown, projects. The bearing body  25  includes a bore  28  which, together with an insertable nail or the like, forms the pivot axis  29  for the base rail  1 . This nail can be driven into the workpiece to be processed, so that the pivot axis  29  is stationary and a movement of the processing apparatus on a precisely given circular line is possible. The adjustment of the bearing body  25  on the intermediate plate  22  makes it possible to adjust the pivot axis  29  precisely at that distance from the base rail  1  which is equal to the distance from the center of the processing tool of the processing apparatus to the base rail  1 . As a result, it is always ensured that the movement of the processing tool of the processing apparatus takes place on the circular line which has a center point coinciding with the pivot axis  29 . In a saw blade-like tool, this ensures that the processing tool does not get jammed. The distance of the marking  10  between the processing tool and the lower end of the base rail  1  shown in the drawing, is always equal to the radius of the circular line on which the processing tool is moving. The radius of the circular line mentioned above can be read at the measuring scale  4 . This significantly simplifies the adjustment process for the processing tool to be moved on the circular line.  
         [0020]     If there is the danger that the nail forming the pivot axis  29  could damage the plate-shaped workpiece at a location where it could still be used, it is possible to omit the nail. In that case, as illustrated in the drawing, a holder  30  is connected to the bottom side of the bearing  25 , wherein the holder  30  has a pin which fits precisely into the recess at the bottom side of the bearing body  25  or  28 . This holder  30  can be clamped on the workpiece by means of a screw clamp or the like. The workpiece can no longer be damaged in this case.  
         [0021]     In a modification of the illustrated embodiment, it is possible to arrange and construct the stop ledges  13 ,  17  and the stop pieces  18  differently. However, it is always of decisive importance that the processing tools are securely held in the desired position. The guide for the support plates  5 ,  6  can also be constructed differently. The intermediate plate  22  and the bearing body  25  can also be constructed in one piece. However, it is then no longer possible to adjust the pivot axis  29  transversely of the longitudinal direction of the base rail  1 . The adjustment of the bearing body  25  for adjusting the pivot axis  29  on the center point of the circular line can be omitted if, for example, the support plate  5  has an adjusting drive through which the processing apparatus can be adjusted relative to the base rail  1  in such a way that the processing tool of the processing apparatus is located on the tangent extending through the center point of the circle.  
         [0022]     The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of the protection defined by the appended patent claims.