US 3631753 A
Apparatus for punching material wherein a workpiece is retained in, and transported by, a punching jig. The punching jig has one or more apertures formed therein, these apertures corresponding to the apertures to be punched in said workpiece. A guide plate, having apertures formed therein which correspond in size and position to those of the punching jig, is placed over the workpiece thereby sandwiching the workpiece between the guide plate and the punching jig. A punch-and-die combination is used to punch the desired apertures in the workpiece, the punch and die being aligned with the apertures of the guide plate and the punching jig by approximately locating the jig through use of the guide plate and subsequently fitting the periphery of the die into the appropriate aperture of the jig.
Description (OCR text may contain errors)
United States Patent George Thomas William Hall Kiikduin, ZH;
Jan Hendrik Sebastiaan Van ljzerloo; Nicolaas A. Althuizen, both of The Hague,
 Inventors  MATERIAL PUNCH 6 Claims, 41 Drawing Figs.
52 U.S.Cl 83/399,
83/413, 83/454, 83/522, 83/648 51 Int.Cl B23q3/18 50 FieldofSearch 83/454,
[5 6] References Cited UNITED STATES PATENTS 3,043.176 7/1962 Johnson et a1. 83/454 X Primary Examiner-F rank T. Yost Attorneys-C. Cornell Remsen, Jr., Paul W. Hemminger,
Walter J. Baum, Percy P. Lantzy, Philip M. Bolton, lsidorc Togut and Charles L. Johnson, Jr.
ABSTRACT: Apparatus for punching material wherein a workpiece is retained in, and transported by, a punching jig. The punching jig has one or more apertures formed therein, these apertures corresponding to the apertures to be punched in said workpiece. A guide plate, having apertures formed therein which correspond in size and position to those of the punching jig, is placed over the workpiece thereby sandwiching the workpiece between the guide plate and the punching jig. A punch-and-die combination is used to punch the desired apertures in the workpiece, the punch and die being aligned with the apertures of the guide plate and the punching jig by approximately locating the jig through use of the guide plate and subsequently fitting the periphery of the die into the appropriate aperture of the jig.
PATENTEUJAN 4:972 31,753
SHEET 02 [1F 13 Inventors GEORGE 72 W. HALL JAN H. 5. WW IJZEQLOO -l glAA$ A: HUIZEN y M Attorney PATENTEUJAN M572 3631.753
SHEET 030E 13 Inventors GEORGE r. w. HALL JA N H- 5. WW IJZEELOO lV/COLAAS A. ALTH [ZEN MAV Attorney PATENTEUJAN 41912 31,753
saw our 13 Inventors GEoRGE 7: w, HALL JAN 5, WW ll/ZERLOO N/COLAAS A. ALTHU/ZEN A Home y PATENTEDJAN 41972 3,531,753
sum USOF 13 Inventors GE RGE r. w. HALL \JAIV H- S. VAN IJZEELOO NIC LAAS A. ALTHUIZEIV Attorney PATENTEI] JAN 4M2 SHEET 08 [IF 13 o o o o o 00 0 1 )0 o o o o oo o 0,
ON ma y Ai m in. M 0 H nW A w NA rm 5&3 A A M n m GMm T PATENTEU JAN 41972 SHEET lDUF 13 Inventors GEORGE 73 w. HALL JAN H. 5. V4 IJZEPLOO N/COLAAS A. ALTHU/Zf/V Attorney PATENTEDJAN 41972 3,631,753
SHEET 120F 13 Inventors GLORGE 72 W. HALL JAA/ II. S V44! IJZERLOO NK'OLAAS A.ALTH [ZEN BYW Attorney MATERIAL PUNCH BACKGROUND OF THE INVENTION The invention relates to a method of and means for punching material in at least one predetennined position whereby the material to be punched is fixed to means for transporting the material to the predetermined position or consecutively to the different predetermined positions.
Such a method of punching material, whereby the term punching is defined as the coaction between a punch and a die to pierce, blank or form (or a combination of these operations) material in sheet, bar or striplike form, is generally known. The material is, in general, firmly clamped or otherwise fixed to a table which is arranged to be moved in two coordinates to bring the material into the desired position at which it is to be punched. The movement may be effected in any of a number of well-known ways, for example by a numerically controlled system or by preprogramming the movements via a plugboard.
In the manufacture of, for example, sheet metal components the quantities to be produced and the intervals between different series play a major role and in many cases the investment in a numerically controlled or programmed machine is not warranted and a drill jig is resorted to, or to positioning of the piece of work with respect to the tool by means of adjustable lineals and locating stops entailing considerable separate handlings. The use of these methods of manufacture results in a production cost that is disproportionately high in comparison to the value of the end product in which the component is assembled. This disproportionately high cost can further increase where it is not only required to provide a pattern of round holes but also to provide holes of irregular form or deformations of the material such as indentations, by separate operations on a punchpress or pressbrake.
SUMMARY OF THE INVENTION It is one of the objects of the invention to provide a method of punching material in one or a number of positions such that manufacturing time is reduced considerably over known methods where the nature and quantities of the components do not warrant cost investment in tooling and machines.
According to the present invention this is achieved because the means consist of a punching jig with at least one aperture which corresponds to and is coincident with a predetermined position and that the aperture or the apertures can engage with a die whereupon the material may be punched by a punch coacting with the die.
The invention will be better understood from the following description read with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a simple but typical component for punching by the method and tools to be described herein;
FIG. 2 shows a punching jig for holding and transporting the component of FIG. 1;
FIG. 3 shows a guide plate for use with the punching jig of FIG. 2;
FIG. 4 shows a part-sectioned side elevation of the component of FIG. 1 located in the punching jig of FIG. 2 with the guide plate of FIG. 3 and ready for the effecting of a punching operation;
FIG. 5 shows a simple setup of a punch and die in a punch press for carrying out a punching operation on the component of FIG. I and employing the punching jig and guide plate of FIGS. 2 and 3 respectively;
FIG. 6 shows a component punched with 12 holes, six of which holes are of a different diameter to the other six;
FIG. 7 shows a punching jig and a guide plate for the punching of the component of FIG. 6;
FIG. 8 shows an arrangement of seven punches and corresponding dies set up in a brakepress for carrying out the method of punching the component of FIG. 6;
FIGS. 9A-9H, 9J-9N and 9P-9R illustrate various punch apertures which may be formed;
FIG. I0 shows the configuration of the extending portion of a die which is adapted to engage with an aperture in a punching jig;
FIG. 11A shows the die of FIG. 10 in engagement with an aperture in a punching jig in which a component and a guide plate is located;
FIG. [18 illustrates a punch utilized in conjunction with the die of FIG. 1 1A;
FIG. 12 shows a stripper for a punch and which is color coded to indicate the diameter of the punch;
FIG. 13 shows a die color coded to indicate the diameter plus the clearance allowance for the punching of a certain thickness of material;
FIG. 14 shows a means for counterbalancing the weights (combined) of a punching jig, a component and a guide plate;
FIGS. ISA-15E show a multiposition punching jig for the punching of components having closely spaced holes of different diameters;
FIGS. 16 and 17 show a means for punching of components with a great weight;
FIG. 18 shows a component having six groups of holes;
FIG. 19 shows a punching jig for the component of FIG. 18;
FIG. 20 shows a press tool for punching all the holes of a group in the component of FIG. 19 simultaneously;
FIG. 21 shows one method of maintaining the punches of the tool of FIG. 20;
FIG. 22 shows another method of maintaining the punches of the tool of FIG. 20 in fixed relationship in a punch holder.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring in the first instance to FIG. I this figure shows a simple and typical component which may be punched with holes at predetermined positions by the method and tools now to be described herein. In this case the component I comprises a mild steel plate of rectangular form and measuring 300 mm. by mm. by 2 mm. thick. This particular component is required to be punched at 20 predetermined positions with holes 2 each of 6-mm. diameter.
FIG. 2 shows a punching jig 3 for holding and transporting the component I of FIG. 1 to effect the punching at the predetermined positions. It comprised a plate of traylike form preferably of a lightweight material such as aluminum having two end portions 4 bent to form handgrips by which the operator can move it, with the component, from one predetermined punching position to another and so on. Four right-angled members 5 are rivetted or otherwise affixed to the tray portion and these serve to prevent movement of the component with respect to a series of holes which extend through the tray and the centers of which holes are coaxial with the centers of the holes to be punched in the component I at the predetermined positions. The holes 6 in the tray are all of like diameter and which diameter permits them to be engaged by a die of the punching tool in a manner to be later described.
FIG. 3 shows a guide plate associated with the punching jig 3 of FIG. 2. This guide plate 7 has precisely the same rectangular form and the width and breadth dimensions of the component l but is somewhat thinner, say 1 mm. The purpose of the guide plate is to give the operator an indication of when the punching jig is approximately in a position in which a particular hole in the tray of the punching jig 3 can be engaged by the previously mentioned die. The relationship between the component 1, the punching jig 3 and the guide plate 7 when cooperatively assembled to carry out punching operations is shown in FIG. 4. In this figure it will be seen that the component 1 is sandwiched between the punching jig 3 and the guide plate 7.
FIG. 5 shows a punch 8 mounted in a punchholder 9 for operation in the directions indicated by the arrows A" and 8" under the action of the ram 10 of a conventional punch press (not shown). The punch 8 accommodates thereon a well-known type of stripper" 11 of hard plastic and having the purpose of stripping material or a component off the punch after a punching operation has been carried out. Arranged for coaction with the punch 8 to effect punching of the component is a die 12, in this particular instance the die 12 is circular in form and may constitute an integral part of a dieblock 13 or function as a separate integer which may be fitted into the die-block 13 as a loose item. In any case the die 12 is arranged to extend vertically above the upper surface of the die-block 13 by an amount which is substantially equal to the thickness of the material from which the punching jig 3 is made, the uppermost periphery of the die 12 is chamfered at approximately 45 at the position designated by the reference numeral 14. The diameter of the vertically extending portion of the die 12 is such that it is slightly smaller, say by 0.05 to 0.1 mm. than the diameter of the holes 6 in the punching jig 3. The engagement of the extending portion of the die 12 in one of the holes 6 in the punching jig 3 is seen in FIG. 5. It will also be noted that the under surface of the component 1 rests on the upper surface of the die 12. It is in these relative positions of the assembled punching jig 3, the component I and the guide plate 7 with respect to the punch 8 and the die 12 that a punching operation is carried out. The consecutive punching of all the holes 2 in the component 1 is a matter of locating the punching jig 3 in successive punching positions, and each of which predetermined positions is determined by the engagement of the die 12 in a hole 6 of the tray portion of the punching jig 3.
Referring now to FIG. 6 this figure shows a component 15 which is required to be punched with 12 holes, six of which are of alike diameter and the other six of which are each different in diameter from each other. The holes of like diameter are designated by the reference letter C and the holes of different diameter are designated by the reference letters "D, E, F," G, H and l." FIG. 7 shows a punching jig l6 and guide plate 17 for the punching of the different sizes of holes in the component 15. The punching of the different holes in component 15 in a normal punch press would necessitate seven different changes of punch such as 8 and respective dies such as 12, to carry out these changes for every different diameter of hole to be punched per component 15, or to punch all components one after another with one size of punch and die and so on for other sizes of punch and die would be time wasting and indeed would nullify any advantages gained by the use of this method. To eliminate such time-wasting setups it is proposed herein to employ a wellknown type press brake in which all the required punches and respective dies can be set up side by side, and by which means all the holes of different diameters in a component such as 15 may be punched one after another without the necessity of either changing punches or dies or removing the component from the punching jig 16.
FIG. 8 shows a set up of seven punches and their respective dies for punching the holes of different diameter in the component 15. For the sake of clarity the punches and respective dies have been designated by the same reference letters as the corresponding holes in the component 15 to be punched and the punching jig 16. In this instance the dies are loose items which are mounted in a common die-block 18 while the corresponding punches are mounted in a conventional manner in the vertically operable ram 19 of the brakepress. Plateaus such as 20 are rigidly affixed to the opposite sides of the dieblock 18 to support the punching jig 16 with its respective guide plate 17 carrying the component 15 during the punching operations. The punching jig 16 with component 15 and guide plate 17 are located in the first punching position and in which position the six holes C" of the same diameter are punched (the term first punching position as used here defines the first of the seven positions along the common die-block at which punching is to take place).
The method and tools herein described are not confined to the punching of holes of circular form, and various forms of holes which may be punched are shown in FIGS. 9A-D:
square, rectangular, triangular, oval and elongated holes with semicircular ends. Material or a component may be part punched also to provide lips which extend outwardly from a surface or punched to provide indentations as shown in FIGS. 9E, 9F, 9G, 9H, 9], 9K and FIGS. 9L, 9M, 9N, 9?, and 9R which are top and front views, respectively. In the cases of holes of square, rectangular, triangular, oval or elongated, or indeed irregular configuration it is necessary to ensure that the jig and component cannot be rotated in the horizontal plane when located in a punching position otherwise the orientation of the hole, indentation or lip with respect to the component will be incorrect. To prevent this occurring that portion of the particular die in use and which extends above the surface of the die-block is either square or rectangular in form as shown in FIG. 10 and indicated by the reference numeral 2]; similarly the corresponding hole in a jig in use of like form. Thus when a die of such form is in engagement with a corresponding hole in a punching jig the latter and the component is prevented from rotation. FIG. 11A shows a part-sectioned pictorial view of the die 21 mounted in a die-block 23 and engaging a correspondingly shaped hole 24 in a punching jig 2S accommodating a component 26, which component is sandwiched between the punching jig 25 and a guide plate 27. The punch 8 and its stripper 11 is shown in FIG. 115.
In order to simplify the setting up of punches and corresponding dies as designated C" to I inclusive in FIG. 8 the respective strippers 11 of FIG. 5 are coded with three peripheral bands of color. The color of the widest of the three bands denoting the diameter of the punch in tens of millimeters, the next widest denoting the diameter of the punch in whole millimeters and the narrowest band denoting the diameter of the punch in tenths of a millimeter. FIG. 12 shows the widths of the bands of color on a stripper and which bands are designated 28, 29 and 30 respectively.
Such a color code may be as follows:
Examples Punch diameter l0s of mm. Units of mm. tenths of mm.
22.2 mm, Dark blue Dark blue Whole stripper colored dark blue) Yellow Red Light blue Dark blue Dark green Y ellow Black Light green Dark brown Light brown Such a system can also be applied to the color coding of the dies corresponding to punches, and to the guide plates of punching jigs, whereby an operator is easily able to identify which punch is to be set up with a particular corresponding die. He is further able to identify the position of a hole, or holes, to be punched by corelating the color coding of the stripper(s) of the punch(es) with the color coding of the hole(s) in a guide plate. In the case of the color coding of dies an extra color position may be required to indicate a particular required clearance between a punch and a die. In general it may be said that the diameter of a hole in a die is greater than the diameter of a corresponding punch by 5 percent of the material thickness to be punched (such a clearance may vary for particular classes of accuracy required in the final hole diameter and the material to be punched). Dies may be color coded to indicate their diameters with clearance by providing four indentations in the upper surface of ever-decreasing diameter. The largest diameter of indentation filled with a color indicating the diameter of the punch in tens of millimeters, the next largest indicating the diameter of the punch in whole millimeters, the next largest indicating the diameter in tenths of a millimeter and the smallest indentation indicating the clearance. The sizes of such indentations in a die 12 are shown in FIG. 13, the largest to the smallest indicated by the reference numerals 32, 33, 34 and 35.
The combined weights of a punching jig, the component and a guide plate might be considerable and cause operator fatigue through the necessity to lift these combined weights every time it is necessary to move the punching jig and its contents from one punching position to another. In order to overcome this a punch press such as illustrated in FIG. 14 and designated by the reference numeral 36 may have a frame such as 37 fitted and from the horizontal member 38 of which two well-known types of balancer 39 are fitted. These balancers house each a cable such as 40 which by spring means is held in a wound-up condition within the casing of the balancer. The tension with which the cable may be maintained in the wound-up condition may be adjusted by a key 41. These balancers have cable tensions that can be adjusted between wide limits. For example, the tension of certain types can be adjusted so that a pull of anywhere between I and kilos is required (according to the adjustment) to unreel the cable out of the casing of the balancer. This tension can be used to counterbalance the weight of the punching jig 3, the component l and the guide plate 7. Two hooks 42 are affixed to the free ends of the cables and these are arranged to engage in holes drilled in the handles 4 of the punching jig 3. The angles which the cables make with respect to the casings of the balancers 39 and the punching jig 3 are such that irrespective of the position of the punching jig 3 with respect to the punch 8 and its stripper 11 these cables are free from the possibility of fouling the punch press.
Closely spaced holes in a component could give rise to dimensional inaccuracies between the centers of such holes due to breakthrough of one aperture in the punching jig into another aperture. With a reasonably experienced operator using the jig to carry out punching operations, a 90 peripheral engagement of a round aperture in a punching jig with a corresponding round die is sufiicient to ensure accurate punching of a component. Any lesser degree of peripheral engagement could possibly lead to misalignment between the punching jig and a die and thus to dimensional inaccuracies between the centers of holes punched in a component. To anticipate this undesirable result a multiposition punching jig is employed such that with a component accommodated in the punching jig in one of the positions certain holes may be punched in the component via apertures in the punching jig which do not break through into each other, and such that when the component is accommodated in another position in the jig other holes which are closely spaced to the first punched holes may be punched via apertures which also do not break through into each other.
If reference is now made to FIG. A there is shown a component 60 having a large hole 61 encompassed by four closely spaced smaller holes 62. In FIG. 158 there is shown a part ofa punching jig 63 with four apertures 64 for the punching of the four previously mentioned small holes, which break through into a center aperture 65 for the punching of the previously mentioned large hole 61. It will be seen that sufficient peripheral engagement of the large center hole with a corresponding die will obtain, but in the case of the four apertures 64 which break through" to the center aperture 65 there may not be sufficient peripheral engagement with a corresponding die and thus the possibility exists that dimensional inaccuracies between the centers of holes will result through misalignment between apertures in the punching jig and corresponding dies.
In FIG. 15C there is shown a two-position punching jig 66 with a component 60 in each half. The large hole 61 in the component may be punched when the component is accommodated in the left-hand half of the punching jig and the jig illustrated at FIG. ISD is utilized, and the component is punched with the four smaller holes 62 when it is accommodated in the right-hand half of the punching and the jig illustrated at FIG. 15E is utilized. When using such a punching jig with a press brake with a set up of two punches, one for the large hole 61 and one for the small holes 62, it will be possible to load the punching jig 66 with two similar components and then punch the large hole 61 in one component 60 and the four smaller holes 62 in the other component, after which the positions of the two components may be changed and punching of the other holes therein may be carried out.
It is self-evident that punching jigs with more than two positions can be employed when necessary in view of very closely spaced holes to be punched in a component.
Assisted lifting and movement of a punching jig, a component and a guide plate by the employment of balancers has already been described. In certain circumstances the combined weights of these items may be such that it is inconvenient to employ balancers and more convenient to move the punching jig and its contents by means of roller tables at each side of the press. In such cases the necessity to lift the punching jig and its contents may be obviated by arranging for the upper surface of the die to lie in the same plane as the bed of the press until the punching jig has been located in such a position that on raising the die it will seek the appropriate aperture in the punching jig. If the periphery of the extending portion of the die is either chamfered or radiused a certain amount of misalignment, between the die and an aperture, the misalignment will be taken up through the action ofthe die, in its vertical movement upward, engaging the peripheral edge of an aperture in the punching jig so that it is forced laterally into alignment. It is therefore proposed that the die should be raised just prior to effecting the punching operation and that punching is inhibited until there is full and proper engagement between the aperture in the punching jig and the die.
This principle is further shown in FIG. 16. A punching jig 98 with a component 99 to be punched and a guide plate 100 rest on the bed 73 of a press. The misalignment of the die 67 and the aperture 101 is indicated with M. The bed contains two pistons 91 and 92 which both extend above the upper surface 74 of the bed under the action of a spring and which can be depressed under the action of the weight of the punching jig, the component and the guide plate. In the depressed situation each piston closes a switch. Moreover, the die closes a third switch in its upper position. The punching press is arranged in such a way that only when the three switches are closed can a punching operation be carried out.
FIG. 17 shows the situation whereby the punching jig with its contents is lifted by the die. So in this situation it is impossible to carry out the punching operation.
Certain components may have several groups of holes. A group of holes in a component constitutes a punching position therein and by utilizing the methods described herein and adapted tools, groups of holes in a number of punching positions can be punched consecutively. FIG. 18 shows a component 1 12 having six groups of holes. These holes, total three per group, are designated by the reference numbers 109, and 111. In this instance the component 112 is 3 meters long and 30 centimeters wide and is of 3-millimeter mild steel. The holes 109, 110 and 111 are of 6, l2 and 18 millimeters diameter respectively.
FIG. 19 shows a punching jig 113 for the component 112. Two ends portions 114 are bent to form handles and similarly extending portions, 115 to inclusive, from opposite sides are also bent to form handles. Other portions 122 of the two opposite sides are sharply bent to form upturned side portions by which means the component 112 is maintained immovable with respect to the punching jig 113 in the width coordinate. The component 112 is maintained immovable in the length coordinate by two strips 123 which are spot welded to the punching jig 113. The guide plate 124 has the same width and length dimensions as the component but is somewhat thinner, i.e., 1 millimeter. The punching jig 113 and the guide plate 124 are both punched to provide apertures which are coaxial with the holes in the component 1 12 which are to be punched.
The tool shown in FIG. 20 includes a die set comprising a bolster 12S and a punchholder 126, the latter of which is guided in its movement relative to the former by two pillars 127 which run in bearings 128. The dies 129, 130 and 131 for punching the holes 109, 110 and 111 in the component 112 are fitted directly into counterbored holes, corresponding to the group of holes to be punched, in the bolster 125. A part cross-sectioned view of the positions of the dies 129, 130 and 131 in the bolster 125 and the positions of the corresponding punches 132, 133 and 134 in the punch holder are shown in FIG. 21, together with the associated strippers for the punches. The punches 132, 133 and 134 are affixed and maintained in the punch holder 126 in counterbored holes by threaded bushes 135 having axial slots 136 by which means they may be screwed in the punchholder 126. These bushes are rendered shakeproof by a well-known liquid-type synthetic adhesive for metals. Alternatively, and as shown in the part-sectioned view of FIG. 22 by a well-known type of epoxy-resin filling 137 poured in the counterbored holes around the shanks and heads of the punches 132, 133 and 134. This type of punch fixing is more suitable for punches required to effect light punching operation.
1. Apparatus for punching material comprising:
a punching jig for retaining and transporting said material, said jig being formed with at least one aperture therein;
a guide plate provided with at least one aperture which is similar to and coincident with said at least one jig aperture, said material being located between said punching jig and said guide plate;
a punch and die aligned with said jig and guide plate apertures for punching said material, said jig aperture being engaged by said die to align said punch and die and wherein the upper periphery of said die extends through said jig aperture and the undersurface of said material rests on the upper surface of said die; and
means for controlling said punch and die as as to allow a punching operation only when said upper periphery of said die extends through said jig aperture.
2. Apparatus for punching material, according to claim 1, wherein the upper periphery of said die is chamfered so as to facilitate engagement between said die and jig aperture.
3. Apparatus for punching material, according to claim 1, wherein said control means comprises a switch which is activated by contact between said under surface of said material and the upper surface of said die.
4. Apparatus for punching material, according to claim 1, wherein the upper periphery of said die which engages said jig aperture is shaped so as to provide a desired rotational orientation between said die and said material.
5. Apparatus for punching material, according to claim 4, wherein said punch, said die and said guide plate apertures are color coded with respect to size.
6. Apparatus for punching material comprising:
a punching jig for retaining and transporting said material,
said jig being formed with at least one aperture therein;
a guide plate provided with at least one aperture which is similar to and coincident with said at least one jig aperture, said material being located between said punching jig and said guide plate;
means aligned with said jig and guide plate apertures for punching said material; and
means for supporting and moving said punching jig, said guide plate and said material, said supporting and moving means comprising;
a frame; two balancers coupled to said frame; and
cables connecting said balance to said punching jig, said supporting an moving means counterbalancmg the weight of the punching jig, the material and the guide plate, thereby facilitating movement thereof.