US2265726A - Sheet punching apparatus and method - Google Patents

Description

Dec. 9, GREENBERG SHEET PUNCHING APPARATUS AND METHOD Fil d Jul 15 1940 2 Sheets-Sheet l V lNV TOR 52W zoafj wz ATTORNEYS Dec. 9, 1941. J. GREENBERG 2,265,726

SHEET PUNCHING APPARATUS AND METHOD Filed Ju ly 15, 1940 2 Sheets-Sheet 2 "I n" In. I I v I ATT'oRNEYs Patented Dec. 9, 1941 UNITED STATES PATENT OFFICE SHEET PUNCHING APPARATUS AND METHOD New York Application July 15, 1940, Serial No. 345,482

9 Claims.

This invention relates to a method and apparatus for punching out of raw sheets smaller sheets of particular geometric size and shape, and has particular application to the punching out of insulating sheets such as mica for use in electrical condensers.

In making condensers of stacked mica and foil sheets it has been the practice for an operator to punch out from irregular shaped sheets of raw mica, the mica insulating sheets of the exact condenser size by means of a punch built of the proper dimensions. The selection ofthe places in theirregular raw sheet from which the punchings were to be taken was left to the discretion of the operator; and the speed of making the punchings and the economy of material depended on the operators skill, for the more provident the selection of areas to be punched out, the less waste of material there would be in the original raw sheet.

By the use of this invention there is obtained an increase in the number of punchings that can be taken from the raw sheets and without any special skill on the part of the operator, and the number of finished sheets which can be punched out within a given time is increased.

The invention will be better understood from the following detailed description and the accompanying drawings, of which,

Fig. 1 illustrates a sheet of raw material such as mica, which is to have punchings made in accordance with this invention;

Fig. 2 illustrates a perspective view of a registering punch for punching registering holes in the sheet of Fig. 1;

Fig. 3 shows a front elevation of the punch of Fig. 21;

Fig. 4 shows a sectional plan view of the punch taken along line 4-4 of Fig. 3;

Fig. 5 illustrates the sheet of Fig. 1 after registering holes have been punched in it by the punch of Figs. 2-4;

Fig. 6 illustrates a perspective view of a punch for punching out finished sheets in accordance with this invention;

Fig. 7 illustrates a sectional plan View of the punch of Fig. 6 taken along line 1! of Fig. 6;

Fig. 8 illustrates a sectional view of the base portion of the punch taken along line 8-8 of Fig. '7;

of the punch of Fig. 7 in a difierent punching position from Fig. '7;

Fig. 10 is a view similar to Fig, 9 but in a different punching position;

Fig. 11 shows the detail of Fig. 9 in still another punching position; and

Fig. 12 illustrates another fragmentary detail at the base of the punch.

Fig. 1 shows an irregular sheet 9 of suitable material, ordinarily raw mica which has been split to a selected thickness. This is to have punched out from it smaller sheets of identical size, usually rectangular, which are to constitute the insulating sheets of a condenser. A registering punch, illustrated in Figs. 2, 3 and 4 is adapted to punch in the raw sheet registration holes located in relation to the area from which the regular finished sheets are to be punched out.

The registering punch comprises a base member Ill provided with two fixed upright posts II and M which may be threaded into the base ID. A die plate I5 is fastened on top of base ID by screws IS. The die plate I5 contains four die holes IT, l8, I9 and 20, these holes being continued all the way through plate IS. 'The base member I 0 is cut away under the die holes at 2| so that punchings can be ejected out the bottom. 3

In front of die plate l5 there is fastened to base l0 bybolts 23, a registering plate 22 having a flat surfaceflush with the surface of the die plate. There are etched on the plate 22 in front of the die holes, a number of lines 24 extending parallel to the row of die holes and a number of other lines 25 perpendicular to lines 24. These lines mark out eight rectangles which correspond to areas which are to bepunched out from the raw mica. I I

Mounted on the posts H and I 4 is the punching head, comprising a heavy head piece 26 having holes 21, and 28, provided with bushings 29 and 30 which fit overthe posts H and I4 so that the head can slide up, and down. A punch aholding plate 3| is fastened centrally to the under-surface of the head piece 26, and this plate is drilled and threaded to hold four punches 32, 33, 34 and 35, theupper ends of which are threaded to screw into the drilled holes of the plate 3 until the shoulders of the lower unthreaded portions of larger diameter of the punches abut tightly against the plate. The punches have small diameter punching ends corresponding to the four die holes in the, die plate J l5 below. There is heldbelow punch plate 3i Fig. 9 illustrates a detail of the base portion a resiliently mounted plate 35 fastened by screws on the ends of bolts 39 and 40, the heads of which rest on shoulders in holes 4| and 42 in head 26.- Compression springs 3! and 38 serve at to hold the plate rather firmly in its lowermost position. Four holes l2 are provided through plate 36, through which the punch ends may and in practice, the raw mica sheet 9 of Fig. 1

is laid over the register plate as shown in Fig. 4

so that the sheet covers the four die holes andalso all of the etched lines. brought down, creating registrations in the form of the four register holes 43, 44, and'46 (Fig. 5). In this punching operation, plate 36 first bears on the sheet 9, and then compresses springs 31 and 38, pushing bolts 39 and) upward in their holes 4| and 42 as the punches come through the respective holes l2 in plate 36 to enter the die holes and thus perform the punching. For this purpose, the punch may be operated in a well-known manner by means of a press.

The mica sheet is now ready tobe punched out,

which is done in a second. punch shown in Figs 6 to' 12. This second punch comprises a base plate 41 on which is mounted a die plate. 48 which maybe fastenedto the base in a suitable manner asby. screws. Y 7

- The die plate 48 contains twodie holes 49 and 59 rectangular inshape and-of the exact dimension .of. the finished sheets to Joe-punched out. The-base plate is provided with somewhat larger holes 12 under the die holes through which a the punchings fall out the bottom. In front of 3 die plate 48 and also mounted on the base 41 is a plate 5| which constitutes the bottom of a rectangularrecess or compartment formed by; three side plates 52, 53 and 54 and the front wall There is located in the rectangular recess, a rectangularblock 56 which 55Lof the die plate.

is. substantially smaller than the rectangular recess so that the block is free to move somewhatfrom end to end and backward and frontward.

The dimension. a .by which the block isshorter than the length of the compartment is equal to thelength a of a punching; and dimension b by which the block is narrower than the width of the compartment is equal tothe width b of a punching. 'Block 56 has attached to its upper surface a plate 51 containing four upwardly protruclin-g. pins 58, 59, 69 and 6]- of the exact size and'location to register with the four holes punched in the mica sheet 9. A hand knob 10 is attached to plate 51 -sothat the block may be moved from one corner to another-of the recess.

.In thisarrangement, when the block is in any oneof the four compartment corners, the four-- pins 58, 59, Stand 6] beat the same relation and distances to the rectangular die holes asthe registration die holes 11, l8,'l9 and 20 bear to a pair of spaced rectangles marked by the etched lines-24and25 on the registering punch. The

four pairs of rectangles so related to the pins in.

the four block portions are, respectively, rectangles'l and-3, 2 and4, =5 and I, and 6 and 8.

The base4-1 is provided with two fixed vertical posts 62 and 63 on which the punch head slides. The punch .head 64 is provided with holes. containing bushings B5 and 66 on which it is adapted to slide up and downover the respective posts. There is attached to the under surface of the head 64aplate 61 through rectangular holes of The punch is then whichthere are fitted tworectangular shaped punches E8 and 69 extending downwardly, the heads of which are held against the under side of the head 64 by the plate 61. The punches may be fastened by providing shoulders under the punch heads which rest on corresponding shoulders in the rectangular holes through plate 61. These punches 68 and 69 are positioned to fit within the die holes in plate 48 when the punch is brought down, so as to stamp out a punching of the same rectangular shape and dimensions.

The raw sheet 9 which has already received the four registration holes is now attached to plate 4 '51 by placing the registration holes over the four pins so that the main part of the sheet which is to be punched out extends back over the die plate 48 as shown in Fig. 7. In Fig. '7 the raw sheet is shown turned over from its position of Fig. 4. When the block 56 is moved by the operator to the upper left hand corner of the rectangular recess, as shown in Fig. 7, the mica is in position to have the two finished sheets numbered I and 3 (seeFig. 9) punched out,as these two areas are over the two die holes in Fig. 7. The block 56.can then be moved forward so that theblock isin the lower left hand corner. of the recess (Fig. '9) in which position the areas numbered 5 and 1 (see Fig. 10) will be punched out. Since the'distance b which the block moves forward is'equal to the width b of one. of the punched rectangles, the

front edges of rectangles 5 and I are taken along.

the same lines as the rear edges of previous punched rectangles I and 3, respectively. The

block 56 can then be moved over to the forward.

right corner (Fig. 10), in which position the two rectangles 6 and 8 (see Fig. 11) are punched out. When the block is then. moved to the rear right corner (Fig. 11) the last twosheets 2 and 4 are punched out. 7 7

By this punching procedure there will always be obtained from each raw sheet eight finished rectangles which will use up all of the material within the larger rectanglecut out, sothat the wastage of mica will be small. Furthermore, with each punching operation there will always be punched out two finished sheets.

It is observed that with the use of this invention it is possible to make punchings from a number of sheets of raw material at one punching operation; for a number of the sheets like that of Fig, 5 which have been individually indexed in the indexing punch of Fig. 2, can be placed one over another on the indexingpins of the punch of Fig. 6, and the punch then operated as has already been described to make the punchings from the several sheets at once.

It should be understood that the relation of the spacing between the punches to the punch dimensions need-not necessarily be such as to leave no material whatever. between the punched rectangles, for if the punches are spaced somewhat further apart some material will be left. But the greater the punch spacing the greater may be the wastage, for a correspondingly greater area will then have to be created within the etched lines 24 and 25 of the registering punch, which would require sheet 9 to be larger in order to cover the'area from which punchings are taken. 7

It will also be understood that the etched lines 24 and 25 which lie within the extrerne bounding lines 24 and 25 need not be present, .as the presence of these interior lines is only for convenience in showing how many punchings can be taken from a raw sheet in case the sheet is too small to take the entire eight punchings from it.

It would be possible, of course, to increase the number of punches. For example, three spaced punches might be used, in which case twelve condenser sheets could be punched out of each raw sheet in the four block positions. This would require a corresponding increase in the area within etched lines 24 and 25 of the registering punch, and correspondingly larger raw sheets 9 would be used.

I claim:

1. A sheet punching device comprising a rectangular punch and a corresponding die, a rectangular compartment near the die, a rectangular block in the compartment movable to each corner of the compartment, the length of the block being at least as much shorter than the length of the compartment as the length of said punch, and the width of the block being at least as much narrower than the width of the compartment as the width of said punch, and a holding device on the block for fixing the sheet in position on the block so that the sheet extends over the die.

2. A sheet punching device comprising a plurality of equal sized punches and a plurality of dies positioned to cooperate with the punches, said punches being spaced apart by a distance at least as great as the length of the punches, a compartment near the die having a plurality of corners, a block in the compartment movable from one corner to another, and a fastening device on the block for fixing the sheet in position thereon, the distances through which the block moves in going from one corner to the next being sufilcient to bring entirely different portions of the sheet over the die every tim the block is moved from one corner to the next.

3. A sheet punching device comprising a plurality of equal sized rectangular punches and a plurality of dies positioned to cooperate with the punches, said punches being spaced apart by a distance equal to the length of the punches, a compartment of rectangular shape, a block of rectangular shape movable from one corner of the compartment to another, the length of said block being as much shorter than the length of the compartment as the distance between said punches, and the width of the block being as much narrower than the width of the compartment as the width of said punch, and a holding device on the block for fixing the sheet in position on the block so that the sheet extends over the dies.

4. Sheet punching apparatus comprising a template marking the area to be punched out of a raw sheet, a plurality of registration punches near the template for punching registration holes in the sheet, a sheet punch for punching finished sheets out of said area, a platform adjacent said sheet punch, a plurality of registration pins on said platform of the same spacing and thickness as said registration punches, said platform being movable to a plurality of different positions in each of which the registration pins bear the same relative location and distance from the sheet punch as the registration punches bear to a corresponding area of said template.

5. Sheet punching apparatus comprising a template marking the area to be punched out of a raw sheet, a registration punch near the template, a sheet punch for punching finished sheets out of said area, a platform adjacent said sheet punch, registration means on said platform having the same registering dimensions as said registration punch, said platform being movable to a plurality of different positions in each of which the registration means bears the same relative location and distance from the sheet punch as the registration punch bears to a corresponding area of said template.

6. Sheet punching apparatus comprising a template marking the area to be punched out of a raw sheet, a registration punch near the template, a sheet punch and die mechanism comprising a plurality of spaced dies and corresponding punches for punching out finished sheets from the said area, a platform adjacent said mechanism, registration means on said platform of the same registering dimensions as said registration punch, said platform being movable to a plurality of different positions in each of which the registration means bears the same relative location and distances from the dies as the registration punch bears to corresponding areas of said template.

7. The method of punching out areas from a raw sheet which comprises placing said sheet over a template, punching a registration mark in the sheet while so placed, registering said mark with a corresponding registering device on a movable platform, moving said platform to successive positions, and punching out said areas in each position.

8. The method of punching out areas from raw sheets which comprises, placing the sheets over a template and punching registration holes in the sheets while so placed, then placing the registration holes of a plurality of the sheets thus registered over a corresponding registering device on a movable platform, moving said platform to successive positions, and punching out said areas in each position.

9. A sheet punching device comprising a plurality of equal-sized rectangular punches and a plurality of dies positioned to cooperate with the punches, said punches being spaced apart by a distance equal to the lengths of the punches, a platform movable to any of four positions which are relatively located as corners of a rectangle, the distance of platform movement from one position to the next in the direction parallel to the lengths of the punches being equal to the lengths of the punches, and the distance through which the platform moves in the direction perpendicular to the first-mentioned direction being equal to the widths of the punches, and a holding device on the platform for fixing the sheet in position to extend over the dies.

JACK GREENBERG.

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