Abstract:
A method and devices are disclosed for punching one or more holes in extruded hollow profiled bars ( 50; 70; 270 ) where a back-up matrix ( 42; 150-550 ) must be inserted and located in precise alignment with the punching male punch ( 66; 90 ) die. Accordingly, the matrixes are mounted to portable mandrel rods ( 40; 140 ) provided with settable stop brackets ( 44; 146 ). The rods are placed in their exact operative punching position, and removed therefter for processing the next bar. The method further provides for simultaniously punching holes in more than one wall of the profiled bars.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the art of punching openings in a workpiece and particularly to press devices for punching elongated, hollow profiled bars, mostly aluminum extruded bars, as used in the building industry for the construction of door and window frames. 
     BACKGROUND OF THE INVENTION 
     In order to better evaluate the contribution to the art of the present invention reference shall be made to FIGS. 1 a-   1   d,  schematically illustrating the traditional, state of the art technique of punching extruded bars. Hence, in FIG. 1 a  there is shown a punching press device generally denoted  10  of any known construction, namely usually provided with a pneumatic cylinder and piston unit  12 , and male punch  14 . 
     To base plate  16  of the device  10  there is connected a generally L-shaped extension bar  18  to which a mandrel rod  20  is fixedly connected (by bolts  22 ). The mandrel rod carries at its free end female punch die (“matrix”)  24  with counter-opening  25  configured to back-up extruded profile  26  during the punching operation. 
     The mandrel rod  20  is provided with a fixable stop bracket  28  for setting the distance of the punched opening from the end of processed profiled bar  26 . 
     It will be noted that the mandrel rod  20  is somewhat flexible and normally, when not in operation, it extends at a certain angle relative to the horizontal slanting in the direction of the punching press  10 . However, when the extruded profiled bar  26  is dressed over the matrix  24  (FIG. 1 b ), the rod  20  becomes precisely aligned, namely slightly raised by the lower wall width W 1  of the bar  26 . This will ensure that the male punch  14  and the female back-up die are in exact vertical alignment with respect to each other to ensure a clean cut of the opening. 
     As evident from FIG. 1 c,  the horizontal alignment or location of the matrix  24  is ensured by a roller or the equivalent device  30  the location thereof again takes into account the side wall width W 2  of the bar  26 . 
     Now, these principles of construction and working process are common to existing punching presses as known now for decades. 
     These devices, however, suffer from numerous drawbacks. First, it is generally inconvenient and time-consuming to insert the sometimes quite long profiled bars  26  into the operative position of FIG. 1 b,  bearing in mind that only small tolerances must be left between the inner cross-section of the bar  26  and the outer shape of the female matrix  24 . 
     Secondly, it is inconvenient to remove the stamped wall pieces of the processed bars from the opening  25  following one or several punching cycles. 
     Thirdly, due to the unaligned or tilted initial position of the mandrel rod  20 , when not in use, it is recommended always to keep a piece of a profiled bar  26 ′ over the matrix  24 —see FIG. 1 d.  This precaution measure is taken to avoid damage to the male punch  14  and/or the matrix  24  if, unintentionally, the press  10  is operated while being in the position of FIG. 1 a,  namely when the matrix counter opening  25  is not in exact vertical register with the opening of the male punch  14 . 
     Lastly, should the back-up opening ( 25 ) be located off-centrally (as exemplified in FIG. 1 c ), and it is required to have another opening be formed exactly oppositely, at the other wall of the bar ( 26 ), it is necessary to employ a separate, additional punching device (press and matrix). 
     A prior art device of the above mentioned kind is disclosed in Document U.S. Pat. No. 3,489,045 relating to a tube punching device for punching openings in profiled bars comprising a male punch and a female punching matrix for backing the bar during the punching operation wherein the punching matrix is attached to an elongate mandrel rod, the mounting constituted by the punching matrix and elongated mandrel rod being permanently mounted to a supporting frame and allowed only to carry out an up and down movement and a limited degree of movement from left to right. Therefore the mounting unit is not removable in operation from the supporting frame. 
     These and additional drawbacks of the existing punching press devices and method of operation are designed to be overcome by the contribution of the present invention. 
     It is thus the general object of the present invention to substitute the fixed mandrel rod and matrix structure by a portable or non-stationary mandrel bar. 
     It is a further object of the invention to provide punch press devices, utilizing the concept of non-stationary mandrel rod, for the application of punched openings at two or three walls of a processed extruded bar simultaneously. 
     SUMMARY OF THE INVENTION 
     Thus, there is provided according to a first aspect of the present invention a punching press device for punching openings in profiled bars comprising a male punch and a female punching matrix for backing the bar during the punching operation characterized in that the punching matrix is attached to an elongated rod removable from the punch device, means being provided for releasably placing the rod in a position suitable for punching an opening in the profiled bar by the male punch against the female punching matrix. 
     According to another aspect of the present invention there is provided a method of punching openings in profiled bars by punching press device comprising a male punch die and a female punching matrix, the method comprising the steps of mounting the female punching matrix to an elongated rod, inserting the matrix and a portion of the rod into the profiled bar; and placing the assembly of matrix and rod in a position suitable for punching the opening by the male punch. 
     The profiled bars may be hollow or non-hollow, as the case may be. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and further constructional features and advantages of the invention will become more clearly understood in the light of the ensuing description of preferred embodiments thereof, given by way of example only, with reference to the accompanying drawings, wherein 
     FIGS. 1 a - 1   d  illustrate the prior art punching technique; 
     FIGS. 2 a - 2   d  schematically illustrate the implementation of the non-stationary mandrel rod concept and practice; 
     FIG. 3 illustrates a length of a profile for exemplifying the application of the invention with regard to forming openings at three sides thereof; 
     FIG. 4 is a schematic elevation of a punching press device for processing the bar of FIG. 3; 
     FIG. 5 is a sectional view along line V—V of FIG. 4; 
     FIG. 6 is a view taken along line VI—VI of FIG. 4; 
     FIG. 7 a  shows a detail of construction for attaining the lateral motion of the side punches of the punching press of FIG. 4; 
     FIG. 7 b  is a section along line VII—VII of FIG. 7 a;    
     FIG. 8 a  illustrates the mounting of the mandrel rod carrier affixed to base plate of the punching press of FIG. 4; 
     FIG. 8 b  is a sectional view taken along line VIII—VIII of FIG. 8 a;    
     FIG. 8 c  is a view taken in the direction of arrow A in FIG. 8 a;    
     FIG. 9 a  is a side view of non-stationary mandrel rod applicable for processing the bar by the punch press of FIG. 4; 
     FIG. 9 b  is a partly sectional view taken along line IX—IX of FIG. 9 a;    
     FIG. 10 a  is a top view of the matrix shown in FIG. 9 a;    
     FIG. 10 b  is a side view of the matrix of FIG. 10 a;    
     FIG. 10 c  is a section taken along line X—X of FIG. 10 b;    
     FIG. 11 shows the operational stage after the insertion of the mandrel rod and matrix into the position ready for punching by the punch press of FIG. 4; 
     FIG. 12 a  illustrates a modified profiled bar to be processed by the same punching press; 
     FIG. 12 b  shows the pressing punch set for processing the modified profiled bar of FIG. 12 a;    
     FIGS. 13 a  and  13   b  illustrate the application of the invention to a still further modified profiled bar; 
     FIGS. 14 a  and  14   b  illustrate the application of the invention to a still further modified profiled bar; and 
     FIGS. 15 a  and  15   b  illustrate the application of the invention to a non-hollow profiled bar. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 2 a - 2   d  there are schematically illustrated the structural elements and practice of the punching method proposed according to the present invention. Thus, a removable mandrel rod  40  is provided, carrying matrix or female punch matrix  42  with punch hole  43  and adjustable stop bracket  44 . It is formed as a stand-alone, portable unit to be used in the manner that will be explained below. 
     The matrix  42  is preferably hollow (see also FIG. 10 below) so that the removal of punched-out pieces is practically done by itself. 
     At the left-hand side of the rod  40  there is formed a circular recess  46 , preferably with a vertical pointer pin  48 . 
     Extruded bar  50  is to be processed, being for the sake of this general example of simple rectangular cross-section. 
     The first stage of operation is illustrated in FIG. 2 b,  where extruded bar  50  is dressed or passed over the female matrix  42 , down to its abutting position against the stop bracket  44 . 
     As shown in FIG. 2 c,  the assembly of bar  50  and mandrel rod  40  is placed on base plate  52  of punch press  62  (see below). The base plate  52  is extended by an L-shaped beam  54 , the latter comprising support bar  56  and upright flat plate  58 . A semi-circular recess  60  is formed at the plate  58  as shown in FIG. 2 d,  exactly fitting around the recess  46  of the bar  40 . 
     The punching press device  62  may be of any conventional construction, namely comprising pneumatic cylinder and piston unit  64 , and male punch  66 . The distance between the punch back-up hole  43  and the recess  46  of the rod  40  is so designed as to achieve the requested precise vertical alignment of the hole  43  and male punch  66 . 
     The punching operation proceeds as in the conventional devices, and thereafter the succession of the operations is reversed. 
     It will be appreciated at this stage that achieved are the advantages of 
     more convenient practice in the insertion of the matrix  42  into the hollow of the bar  50 —instead of the reverse procedure of dressing the bar over the matrix when the later is fixed to the base plate of the device; and 
     removal of the residual stamped-out bar pieces from the hole  43  is achieved almost by itself, when the matrix  42  is separated from the bar  50 . 
     Additional valuable advantages of replacing the conventional fixed mandrel rod structure by the maneuverable mandrel rod technique as herein proposed would be better appreciated by the following, more advanced example of processing an extruded bar generally denoted  70  in FIG. 3, of the shape vastly used in the construction of doors made of profiled aluminum extruded bars. In this example bar  70  must be formed with 
     a rectangular opening  72  at its top wall; 
     a first, circular opening  74  and a second keyhole shaped opening  76  at one-side wall; and 
     symmetrically opposite openings  78  and  80  at the other side wall of the bar  70 . 
     These openings are used for installing the standard handle and cylinder lock mechanism of the doors. The precise opposite alignment is therefore of vital importance. 
     FIG. 4 schematically illustrates the construction of a press punch device useful for carrying out the operation of punching out the openings  72 ,  74 ,  76 ,  78  and  80  in a single high precision operation. Thus, punching press device  82  comprises a pneumatic cylinder unit  84  for operating piston rod  86  which causes the reciprocating movement of cross plate  88 . This movement is transferred to male punch  90 , suitably shaped for cutting the opening  72  of extruded bar  70 , and also to a pair of side or lateral punches which will be Ad described in more detail further below. 
     The reciprocable cross plate  88  is guided by pair of columns  92  and  94  which are affixed to base plate  96  at the bottom side and carrying top plate  98  at the other side. As better is seen in FIGS. 5 and 6, side punch  100  is designed to cut the opening  74 ; punch  102  punches out the opening  76 ; punch  104  punches the opening  78 ; and punch  106 —opening  80 . 
     The punches  100 - 106  are passed through the respective guide plates  110  and  112  and are carried by plates  114  and  116 , respectively. 
     Concentrating first on the right-hand side of the punching mechanism, it will be seen that plate  114  is coupled to reciprocable double rail member  118  as seen in FIG. 7 b.  An inclined pin-and-slot coupling mechanism is implemented, in the form of block  122  connected by screw thread rod  124  to the reciprocable cross plate  88  (see FIG. 4) and thus reciprocable in unison with the male punch  90 . Vertical position adjustments are attained by opposite bolt and nut  124   a  and  124   b.  Block  122  is formed with slot  126  extending at an angle relative to the vertical as shown in FIG. 7 a.  Pin  128  is passed through the slot  126 , mounted between the legs of the rail  118 , for applying a sidewise or transverse movement (to the left) of the carrier rail  118 , the punches carrying plate  114 , and thus to punches  100  and  102 . Hence, upon downward stroke of the block  122 , openings  74  and  76  are perfected. 
     It will be readily understood that any other, equivalent, cross-wise movement transmission arrangements may be employed, such as cams or link arms, known per-se. 
     A similar, mirror-image structure is provided at the other, left-hand side of the punching press  82  (with regard to punching of openings  78  and  80 ), which therefore need not to be described in greater detail. 
     Turning now to FIGS. 8 and 9, the application of the non-stationary mandrel rod support concept is illustrated. Hence, to the side of base plate  96  (FIG. 4) there is mounted extension bar  130  (of a rectangular cross section as shown), e.g. by a pair of nuts  132   a  and  132   b.  Upright plate  134  is provided with recess  134   a,  similar to the recess  60  in FIG. 2 d.    
     Mandrel rod  140  is provided, with recess  142  at its free end, preferably with upright pointing pin  144 , and a longitudinally adjustable stop bracket  146  with locking screw  148 . 
     Female matrix  150 , details of which are better seen in FIGS. 10 a - 10   c  is carried by the mandrel rod  140 . Thus, the matrix  150  is hollow (to facilitate evacuation of stamped-out pieces), and provided with the counter backup punching openings  72   a  through  80   a  conforming the respective openings  72 - 80  to be punched at the bar  70 . 
     The final operative position is seen in FIG. 11 wherein profile  70  is shown, after insertion thereinto of the matrix  150  in the aligned position as dictated by its length from the recess portion  142  of the mandrel rod  140  and the recess portion  134   a  of the upright plate  134  (see FIG.  8 ). 
     Referring now to FIGS. 12-15, it will be readily understood that yet a further unique advantage of the invention is attained, in that the same set of punches ( 90  and  100 ,  102 ,  104  and  106 ) can be used for processing different shapes of profiled bars. 
     Hence, FIG. 12 a  shows a profiled bar  270  where an identical series of openings  72 - 80  for cylinder lock system (cf. FIG. 3) is to be punched. FIG. 12 b  shows the relevant portion of the punching press  82  (FIG.  4 ). The profile  270  is clamped for punching, only this time spacing blocks  270   a  and  270   b  are required to fill-in because of the smaller width of the profiled bar  270 . 
     In a similar manner, profiled bar  370  is processed by the same pressing punch with aid of spacing blocks  370   a,    370   b  and  370   c;  and profile  470 —with blocks  470   a,    470   b  and  470   c  (see FIGS. 13 a,    13   b  and  14   a,    14   b ). 
     It is sometimes requested to have non-hollow profiled bars punched with the same rectangular opening  72 —see FIGS. 15 a - 15   b.  In this case, the replaceable matrix  550  will have to be made with “fictitious” counter-holes  574   a  through  580   a  which take no active part in the punching process. 
     The advantages derived from the method of punching forming the subject matter of the present invention are clearly evident. The vis-a-vis, in register location of the side walls opening is ensured by the very structure of the punching press and assemblies, and the same applies to the relative location of the top rectangular opening  72   a.  The process is by far more accurate and speedy due to the implementation of the non-stationary mandrel rod concept as explained and exemplified above. 
     Moreover, as already mentioned, should it be desired to apply a pair of oppositely located openings which are both off-centered relative to the axis of symmetry of the processed bar, only one and single press device is required, operable with a single, non-stationary matrix and mandrel rod as proposed by the present invention. 
     All that is requested are means for placing the matrix (and rod) at two, parallel, transversely distanced locations (conforming to twice the distance between the center of the opening and the bar&#39;s axis of symmetry). This will enable to punch the first opening in the usual manner as described above, and then the second opening, by merely mounting the profiled bar on the matrix in an inverted position, and carrying on the second punch at the said distanced location of the matrix/bar assembly. 
     While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as exemplification of the preferred embodiments. Those skilled in the art will envision other possible variations that are within its scope. Accordingly, the scope of the invention should be determined not by the embodiment illustrated, but by the appended claims.