Patent Publication Number: US-2022212274-A1

Title: Device for Machining Window or Door Frames Welded from Profile Pieces

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application (under 35 USC § 371) of PCT/EP2020/073916, filed Aug. 27, 2020, which claims benefit of German application No. 10 2019 123 144.2, filed Aug. 29, 2019, the contents of each of which are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field and State of the Art 
     The invention relates to a device for machining frames welded from profile pieces such as, for instance, window or door frames made of plastic, comprising at least one machining head and machining tools which are arranged on it and which can be moved into the appropriate machining position on the frames. 
     Such a machining device is disclosed, for example, in U.S. Pat. Appln. No. 2007/0234550 A1. This device has several machining tools that are held in a tool carrier which, in turn, can be moved in two directions that are perpendicular to each other. In addition, there is a second movable tool carrier that is arranged to the side of the tool carrier and that has a machining tool for purposes of machining a profile leg of the window frame. The second tool carrier can be moved in the diagonal direction of the frame corner that is clamped in the machine, so that the corner of the frame as well as a profile leg can be machined with one single machine. 
     International patent application WO 2015/031793 A1 discloses a window machining unit having a drive that is held on a robot arm and that, on its opposing and projecting drive shafts, has a socket for tools such as, for example, a sawblade on one side and a milling cutter or a drill bit on the other side. Since the machining unit is arranged on a robot arm, the tools can be moved in all three spatial directions and can also be rotated. 
     A drawback of the prior-art devices is the design effort needed so that the tools situated on a robot arm can be moved and rotated, or the effort needed to arrange a second movable tool carrier and the relatively small number of tools as well as the high effort in terms of the programming and software required for positioning the tools. 
     Before this backdrop, the invention is based on an objective of refining a device of the above-mentioned type in such a way that, with a simple construction and a reliable operation, it is possible to machine the corner joints of the frames as well as to machine the frame legs, for example, in order to create profiled through holes, drilled holes and the like. 
     SUMMARY OF THE INVENTION 
     The device according to the invention for machining frames welded from profile pieces such as, for instance, window or door frames made of plastic, comprises at least one machining head with machining tools which are arranged on it and which can be moved into the appropriate machining position on the frame that is to be machined. 
     The machining head can be swiveled around an axis and has one positioning shaft which is arranged at an angle to this swiveling axis and on which the machining tools are arranged. 
     Since the machining head can be swiveled and the positioning shaft that holds the tools can be rotated, the machining of a corner of the frame as well as the machining of a profile leg can be carried out by one single device and in one single clamping position of the frame. For instance, in order to machine a frame corner, the machining head is moved into the initial position and then aligned diagonally to the frame corner by swiveling the machining head around the swiveling axis using its positioning shaft that holds the machining tools. The desired machining tool is selected by rotating the positioning shaft and then the outer and/or inner corner as well as the visible surfaces are machined by moving the machining head towards and/or away from the frame corner. Once the frame corner has been finished, for example, by employing other machining tools, then a frame leg or profile leg can be machined. For this purpose, the machining head can be moved or brought into its initial position, then it can be aligned perpendicular to the profile leg that is to be machined by being swiveled around the swiveling axis using the positioning shaft, after which the desired tool can be selected by rotating the positioning shaft and can be brought into the working position by being moved or placed onto the profile leg. 
     In the case of water slits or other such through holes, for instance, in order to drill holes, the machining head can be moved along the frame leg together with the machining tool that engages with the appertaining frame leg. It goes without saying that the reverse mode of operation is likewise possible, whereby firstly the frame leg and subsequently the frame corners are machined, and a combination of the machining steps is also conceivable. 
     This attains a complete machining of window and door frames. 
     The device according to the invention entails a high degree of flexibility. Machining on the profile section or frame leg can be easily achieved from a technical standpoint. 
     According to a first embodiment, it is provided that the positioning shaft with the machining tools arranged on it can be positioned in the rotational direction by means of an actuating drive. As a result, a fast and precise selection of the appertaining machining tool can be made and the tool can be precisely moved into place on the frame corner or on the specific frame leg that is to be machined. 
     Preferably, the swiveling axis and the axis of the positioning shaft are aligned essentially perpendicular to each other, so that all of the machining positions on the frame and on the frame corner can be reached. Preferably, the swiveling axis runs perpendicular to the clamping plane of the frame, whereas the axis of the positioning shaft runs parallel to the plane of the frame. 
     According to another embodiment of the invention, it is provided that the machining head can be additionally moved in three axes and it is preferably held on a carriage that can be moved in three axes. In this manner, the carriage with the machining head can be placed diagonally relative to the clamping plane of the frame, which further enhances the universal deployment of the device. Thus, every position on the frame can be reached using a wide array of tools. 
     According to the invention, it is provided for the positioning shaft to extend on both sides of the machining head and to have machining tools at both end areas of the positioning shaft. As a result, a plurality of tools can be arranged at the ends of the positioning shaft so as to machine a wide array of frame geometries and frame specifications when it comes to through holes and drilled holes on the frame leg. The arrangement of various tools at opposite ends of the positioning shaft yields a compact structure and a large number of tools can be installed. This also allows complete machining of a crosswise section of the frame. 
     Another idea of the invention provides for the positioning shaft to be configured so that it can be adjusted relative to the machining head in one axial direction. This accounts for even more universal positioning possibilities for the machining tools, even at places of the frame that are otherwise difficult for the machine to access. In this context, the tool can be arranged on tool carriers arranged at both ends of the positioning shaft, as a result of which the device can be adapted to any dimensions of the profile pieces and to different requirements. 
     Of course, it is also conceivable to provide for stationary and/or motor-driven tools, which likewise increases the versatility of the machining possibilities. 
     In this context, the axes of the machining tools can be aligned perpendicular or parallel to the axis of the positioning shaft, which reduces the possibility of a collision between the frame that is to be machined and tools that are not currently needed. 
     The same goal is also pursued by the measure according to the invention in which one of the tools, at least in one rotational direction of the associated end of the positioning shaft, projects relative to the machining head, at least in certain areas, so that the appertaining machining tool can be used freely without a collision occurring between the machining head and the workpiece. 
     It is especially advantageous according to the invention for at least one motor-powered drive, especially an electric drive, to be provided for the machining tools, said drive having a continuous output shaft and having tool holders for rotating machining tools arranged at both shaft ends. As a result, tool holders that are located at opposite sides of the output shaft and that serve to hold rotating machining tools can be provided on one shared drive, a measure which considerably reduces the technical effort needed to drive the machining tools. 
     In the eventuality that at least two motor-powered drives for machining tools are provided at the ends of the positioning shaft, then, according to the invention, these tools are arranged one behind the other in the axial direction of the positioning shaft, and their tool axes are aligned with respect to each other at an angle, preferably at a right angle. This translates into a particularly compact structure, without the tools that are not being used at that moment colliding with the workpiece. 
     The positioning shaft is preferably positioned employing computerized numerical control (CNC), so that the tool can be positioned without pneumatics and only by means of the CNC program, thus yielding a high degree of precision and reproducibility. 
     When it comes to achieving a very short cycle time during the machining of frames, it is provided for at least two machining heads to be provided that preferably simultaneously machine the corners and/or side profiles of the frame. Naturally, it is also conceivable for two machining tools to be provided on both sides of the frame that is to be machined, so that an additional reduction of the cycle time for the machining of frames can be achieved. 
     Additional objectives, advantages, features and application possibilities of the present invention can be gleaned from the description below of several embodiments making reference to the drawing. In this context, all of the described and/or depicted features, either on their own or in any meaningful combination, constitute the subject matter of the present invention, also irrespective of their compilation in the claims or in the claims to which they refer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In this context, the following is shown, at times schematically: 
         FIG. 1  a possible device for machining frames, comprising two carriages in an initial position, 
         FIG. 2  an enlarged view of a machining head according to  FIG. 1 , 
         FIG. 3  a partial view of the device shown in  FIG. 1 , comprising machining heads and the clamping of a profile in an initial position, 
         FIG. 4  the device as shown in  FIG. 3 , in the working position for the inner corner machining, 
         FIG. 5  another working position of the device for milling the inner corner, 
         FIG. 6  the device as shown in the preceding figures, in a working position for machining a profile leg or a crosswise section of the frame, and 
         FIG. 7  the device as shown in the preceding figures, in a working position for machining a lengthwise section of the frame. 
     
    
    
     DESCRIPTION OF THE DISCLOSURE 
     The  FIG. 1  shows an overall view of a device for machining the corner area of window or door frames  5 , whereby said device makes it possible to machine the frame corner as well as the profile leg in the same initial position of the frame  5 . 
     The frame  5  consists of plastic profile pieces or frame legs  1 ,  2 ,  3 ,  4  that have lengthwise sections and crosswise sections and that have first been mitered and subsequently welded at the corners. The weld that has been created by the welding procedure and that needs to be machined already for optical reasons runs in the area of a corner at an angle of 45° relative to frame legs or profile pieces  1  to  4  that have been joined together. 
     The corner joint is machined by means of milling, chiseling or, for example, drilling tools  6  to  13 . In order to move the machining tools  6  to  13  into the working position at the specific corner areas of the frame  5  that are to be machined, the machining tools  6  to  13  have to be movable in a socket of the machining device horizontally or parallel to a clamping plane  27  of the frame  5  in the XY-direction as well as in the Z-direction perpendicular to the clamping plane  27 . The X-, Y- and Z-directions are each depicted in  FIGS. 1 and 2 . In addition, the rotational or swiveling directions Q 1  and Q 2  are indicated in  FIG. 2 . 
     Towards this end, there are two carriages  36  that can be moved in the X-direction and that are situated in a machine rack  35 , and each carriage holds a machining head  14 ,  25  that can be moved in three spatial directions. It is likewise conceivable for two machining heads  14 ,  25  that are used on one side of the frame to each be arranged on the carriage  36 . The carriage  36  can be moved by means of linear actuators such as stepping motors or spindle motors, or else, for example, by compressed air-powered piston cylinder units. The movement of the machining head  14 ,  25  can effectuate the machining of the top as well as of the bottom of the clamped frame  5 . 
     The machining tools employed in the embodiment selected here comprise not only stationary tools  10  to  13  such as, for instance, chiseling blades to remove the weld beads that have formed in the corner area of the frame  5  during welding, but also rotating tools  6  to  9  such as, for example, drills to create a sealing groove, side-and-face cutters to ablate the weld bead on the outer corner of the frame  5  and the like. 
     The machining tools  6  to  9  are employed to machine profile legs or profile pieces  1  to  4 , for example, in order to drill holes into the outside of the profile legs or to create elongated holes. 
     The machining head  14 , which is mounted, for instance, on a movable carriage  36  as shown in an enlarged view in  FIG. 2 , can be swiveled around a vertical axis  15  in the embodiment selected here, as illustrated by the double-headed arrow labelled Q 1  in  FIG. 2 . For this purpose, an actuating drive  28  is arranged on the carriage  36  or support which, in the embodiment selected here, uses a toothed belt  30  to effectuate the swiveling of the machining head  14  relative to the carriage  36 . 
     The actuating drive  28  can have, for instance, an electric motor which, by means of a sprocket  29  arranged on its output shaft, drives the toothed belt  30  which swivels the machining head  14  around the swiveling axis  15  by means of a toothed wheel  31 . 
     A positioning shaft  16  on which the machining tools  6  to  13  are arranged is likewise mounted in the machining head  14 . The positioning shaft  16  can be adjusted in the rotational direction by means of an actuating drive  26 . In the embodiment selected here, the swiveling axis  38  of the positioning shaft  16  is aligned perpendicular to the swiveling axis  15  of the machining head  14 , whereby the swiveling axis  15 , in turn, is aligned perpendicular to the clamping plane  27 . 
     As can especially be seen in  FIG. 2 , the positioning shaft  16  extends to both sides of the housing  37  of the machining head  14  and it supports the machining tools  6  to  13  at its ends  16   a ,  16   b . In this context, tool carriers  17 ,  18  on which the tools  6  to  13  are held preferably so as to be replaceable are arranged at both ends  16   a ,  16   b  of the positioning shaft  16 . 
     As shown in  FIG. 2 , the positioning shaft  16  has a swiveling axis  38  around which the positioning shaft  16  is arranged so as to swivel, as illustrated by the double-headed arrow labeled Q 2 . 
     As can be seen in the figures, stationary tools  10  to  13  such as, for instance, draw blades, are provided on the tool carrier  18  and motor-driven machining tools  6  to  9  are arranged at the other end  16   b  of the positioning shaft  16  on the tool carrier  17 . 
     The axes  21 ,  22  of the motor-driven machining tools  6  to  9  can be aligned either parallel or perpendicular to the positioning shaft  16 . 
     As can especially be seen in  FIG. 2  in the embodiment selected here, two motor-powered drives  19 ,  20  for the machining tools  6  to  9  are provided at one end  16   b , whereby said motor-powered drives are arranged one behind the other in the axial direction of the positioning shaft  16  and their tool axes are aligned at a right angle with respect to each other. The motor-powered drives  19 ,  20  have a continuous output shaft whose two shaft ends  23 ,  24  have tool holders for the rotating machining tools  6  to  9 . As a result, in each case, one drive can drive two machining tools  6 ,  7  or  8 ,  9 . 
     When it comes to positioning the positioning shaft  16 , a computerized numerical control (CNC) is provided which allows a precise positioning of the tools  6  to  13 . 
     For the machining, the frame  1  is placed into a frame plate  32  and secured with clamping means  33  and centering means  34 . 
     The clamping means  33  can be, for example, hold-down clamps that clamp the frame  5  onto the plate  32  of the machine rack  35 . There are also centering means  34  that engage with the inside of the frame  5  or of the profile legs  1  to  4  and that center the frame  5  and secure it against shifting in the clamping plane  27 . 
     When it comes to the machining itself, the machining heads  14  are initially put into position. For this purpose, the carriages  36  that carry the appertaining machining head  14  are placed onto the frame  5  that is to be machined. Then, for example, in order for the corner to be machined, the appertaining machining head  14  is swiveled around the swiveling axis  15  diagonally to the frame, e.g. by 45°, by means of the actuating drive  28 . Subsequently, preferably at the same time, the requisite tool  6  to  13  for the corner machining is selected through a rotational movement of the positioning shaft  16 .  FIG. 3  shows the position of the machining heads  14  for the inner corner machining using a side-and-face cutter. 
     Then the appropriate machining head  14  with the tools  6  to  13  is moved once again into its initial position and the next machining tool  6  to  13  is selected by rotating the positioning shaft  16  and/or by rotating the machining head  14 ,  25 . In this context,  FIG. 4  shows the machining of the frame corner with a machining tool  12  configured as a draw blade. 
     In  FIG. 5 , the machining heads  14 ,  25  have been rotated around the swiveling axis  15  by 180° in comparison to the position shown in  FIGS. 3, and 4 , so that now a side-and-face cutter  8  is employed for milling the inner corner. 
     In the machining situation shown in  FIG. 6 , the positioning shaft  16  of the machining head  14 ,  25  is aligned parallel to the profile piece  2 , in other words, it is swiveled once again by 45° relative to the position shown in  FIG. 5 , so that now a contouring milling disc or, for instance, a profiling cutter can then machine the outer contour of the frame  5 . 
       FIG. 7  shows the work steps employing other tools such as, for example, the machining of the profile piece  1  to  4  in order to create water slits along the profile piece  4  by means of a milling cutter  6 . 
     The device according to the invention accounts for a high level of flexibility and also allows a quick adaptation of the device to a wide array of dimensions of the specific frame  5  that is to be machined. 
     The invention is not limited only to dual-head machining, but rather, the provision can also be made for a four-head machining device having several, especially two, machining heads  14 ,  25 . 
     LIST OF REFERENCE NUMERALS 
     
         
           1  profile piece 
           2  profile piece 
           3  profile piece 
           4  profile piece 
           5  window or door frame 
           6  machining tool 
           7  machining tool 
           8  machining tool 
           9  machining tool 
           10  machining tool 
           11  machining tool 
           12  machining tool 
           13  machining tool 
           14  machining head 
           15  swiveling axis 
           16  positioning shaft 
           16   a  end of the positioning shaft 
           16   b  end of the positioning shaft 
           17  tool carrier 
           18  tool carrier 
           19  drive 
           20  drive 
           21  tool axis 
           22  tool axis 
           23  shaft end 
           24  shaft end 
           25  machining head 
           26  actuating drive 
           27  clamping plane 
           28  actuating drive 
           29  sprocket 
           30  toothed belt 
           31  toothed wheel 
           32  frame plate 
           33  clamping means 
           34  centering means 
           35  machine rack 
           36  carriage 
           37  housing 
           38  swiveling axis 
         X axis 
         Y axis 
         Z axis 
         Q 1 , Q 2  rotating or swiveling axis