US2355344A

US2355344A - Sheet material punching apparatus

Info

Publication number: US2355344A
Application number: US426447A
Authority: US
Inventors: George F Wales
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-01-12
Filing date: 1942-01-12
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

I Aug. 8, 1944. WALES 2,355,344

SHEET MATERIAL PUNGHING APPARATUS Filed Jan. 12, 1942' 5 Sheets-Sheet l Hm, W; in

m 7; w m" @67 M INVENTOR.

BY W

ATTORNEYS SHEET MATERIAL PUNCHING APPARATUS Filed Jan. 12, 1942 3 Sheets-Sheet 2 AT TOP/VEYS 1944. G. F WALES 2,355,344

SHEET MATERIAL PUNCHING APPARATUS Filed Jan. 12 1942 3 Sheets-Sheet 5 Z INVENTOR.

BY {W W; 6

AT TORNEYS' the same after it becomes dull.

Patented Aug. 8, 1944 UNITED STATES PATENT OFFICE snas'r MATERIAL ruuonme srrm'rus George F. Wales, Kenmore, N. r. Application January 12, 1942, Serial No. 42am as Claims. 164-94) This invention relates to a punching apparatus which is more particularly intended for producing a plurality of closely spaced perforations in sheet material, such as sheets of metal, and other articles, such as strips and angle bars which form parts of aeroplane structures and the like, although this apparatus may also be advantageously used for other work, particularly when the same apparatus is used for perforating articles varying in thickness.

units embodying this invention may be assembled in a row close together for producing rows of closely spaced openings in the workpiece.

Another object of this invention is to organize thespring means of the stripping mechanism so that the spring effect may be readily varied and thus permit of selectively adapting the power of the spring means of the stripping mechanism to suit the thickness or character of the metal from operation of perforating the same has been completed.

A further object of this invention is to provide simple and efllcient means for adjusting the die and punch of this perforating apparatus when the same are originally installed and also to take up forshortening of the punch due to sharpening A still further object of thisfinvention is to provide means whereby the individual members of a plurality of punching elements may be adjusted independently of each other as to length and thus permit of great latitude in causing the several punch elements to effect their perforating operations either simultaneously or successively in accordance with the thickness of the stock which is being perforated or to meet other conditions.

A punching apparatus of the general type to ance with the present improvements arranged side by side.

Fig. 3 is a top plan of one of the punching units containing the present improvements.

Fig. 4 is a horizontal section, taken on line |4, Fig. 1.

Figs. 5 and 6 are fragmentary views, similar to the upper part of Fig.1, showing various spring selections and arrangements to suit the opera- Y which the punches must be withdrawn after the which the present invention relates is shown in tions of punching and stripping sheet metal which differs in thickness from that for which thespring means in Fig. l is intended, and Fig. 6 also showing a diflerent form of spring for lifting the punch guide as compared with that shown in Figs. 1, 3, 4 and 5.

Figs. 7, 8, 9 and 10 are fragmentary vertical sections showing various forms of dies and means for adjusting the same in accordance with this invention which differ from that shown in Figs. 1, 2, 5 and 6.

Figs. 11, 12, "13, 14, 15, 16, 1'7, 18 and 19 are fragmentary vertical sections showing various forms of punches and means for adjusting the same.

In the following description similar characters of reference indicate like parts in the several figures of the drawings.

Referring to Figs. 1 and 2, the numeral i0 represents the lower supporting bed or base which forms part of the main frame of the punching press, press brake or the like and II the upper guide head of the same which has its rear part connected with the corresponding part of the bed by an upright arm or standard [2. 1 Above the bed is arranged a ram 9 which may be guided on the frame head and reciprocated vertically by any suitable means. Upon the bed of the frame is mounted a transverse horizontal supporting and guiding rail l3 which may be provided with a longitudinal slot [4 registering with a similar slot I5 in the bed. Upon this rail a plurality of punching 'unitsare mounted in a transverse row each of which units embodies the present invention and is constructed as follows: The numeral l6 indicates in general the holder which supports the various working parts of a punching unit and comprises a lower die shoe I1, an upper punch head or horn l8 arranged above the shoe and spaced therefrom by a gap I9 and an upright standard or post20 connecting the rear parts of the shoe and horn, as shown in Fig. 1. Each of these holders is comparatively narrow so that the same can be arranged closely together in a row crosswise of the press to permit of producing rows of closely spaced openings in sheets of metal, although these holders may also be spaced comparatively far apart to suit the requirements metal which are to be perforated. Although these holders may be mounted in of the particular. sheets of plish this as follows:

Each of the holders rests with its underside on the upper side of the rail and provided on its underside with a longitudinal groove 2| which receives an upwardly projecting tenon or tongue 22. The holder when free can be slid horizontally and transversely on the rail relative to the frame into the desired position but is held against fore and aft movement by'cooperation of the tongue 22 and groove 2| formed respectively on the rail and holder and after such adjustment the holder may be secured in place by a vertical fastening screw bolt 23 passing through the front parts of the shoe and rail and provided at its upper end with a head 24 bearing against the top of the shoe and having a clamping nut 25 at its lower end which is arranged in a T-slot 26 formed in the front part of the rail.

Upon the shoe of each holder is. mounted a die and upon'the horn of the respective holder is mounted a vertically movable punch which cooperates with said die for producing perforations in the sheet. material placed between the companion die and punch. The die shown in Figs. 1 and 2 has an upright cylindrical body 21, the lower part of which is tightly held by a driving or press fit in a cylindrical socket 28 in the respective holder shoe and the upper part'of which has a vertical die opening 29 provided with a cutting edge 30 at its upper end and a slug discharge chute 3| extending from the lower end of the die opening laterally to the periphery thereof.

"' For the purpose of positively'locating the upper end. of the die 21 in the desired position when originally assembling the parts and also to compensate forany reduction in its height when the upper end of the die is resharpened after being worn dull, adjustable meaans are provided for supporting or backing the die in its vertically adjusted position on the shoe. The vertically adjustable support'for this purpose may be varied but those shown in Figs. 1 and 2 are satisfactory on account of their simplicity and the ease and convenience with which this adjustment may be effected. As there shown these adjusting means comprise a vertically adjustable abutment having the form of a screw plug 32 which works in an internally screw threaded opening 33 forming a downward extension of the socket 28. This screw plug is provided at its lower end with a non 'circular recess 34 which is adapted to receive a wrench or other tool to turn the abutmerit screw 32 so that the same will either move upwardly or downwardly and thus support the die either in a raised or lowered position as may be necessary for bringing the top of the die into the desired position. I

When it is desired to raise the die 21. afterthe upper end of the same has been sharpened, or for any other reason, the holder is removed from the rail 13 and the supporting screw 32 is: removed and then the die is hit by means of a suitable'tool striking against its lower end until the-.die'has been moved upwardly the requisite distance after which thebacking screw 32 is replaced and engaged tightly with the lower end of thedie. so as to support the latter firmly in its adjusted position. 7

When effecting such adjustment of a die a snap gauge of well known construction is used for resetting the die so that its upper end is in the proper position, this gauge measuring the distance from the bottom of the holder to the face of the die and thus enable a plurality of such units to be maintained at the desired height.

When a. plurality of punching units aiemployed in the press and it is desired that the I upper: ends or faces of the dies of the several units are on the same level or at different levels, the means for adjusting the dies vertically makes this possible inasmuch as each die can be adjusted individually inqaccordance with the amount of material which has been removed upon sharpening the same when dull.

For convenience in perforating the flanges 35 of metal bars which are L-shaped in cross section and have beads or bulbs 36011 the inner sides of these flanges, the die is provided below its upper end and opposite its chute 3| with an undercut or recess 31 so that when one of these flanges rests with its underside on the die, the bead or bulb on the other flange will project into the recess 31 and permit the respective flange to be perforated in the desired location relative to the corner of the angular bar, as shown in Fig. l.

The numeral 55 represents the vertical body of the punch and 56 the cutting bit at the lower end of the body which is adapted to coope 'te with the cutting edge of the die opening 29 f/the die for perforating sheet material or other article which is placed between the die and punch. The lower part of this punch body is guid 'd'in a guiding and stripping sleeve or tube 5T which slides vertically in a guide opening 58 formed in the front part of the horn I8 of the "holder, as shown in Fig. 1. At its lower end the guide sleeve 51 is provided with a reduced guide opening 59 for receiving the correspondingly reduced bit of the punch. The punching, guiding and stripping sleeve or tube is yieldingly held in its elevated position by lifting means which in accordance with the showing in Figs. 1, 3, 4 and 5 consist of a curved leaf-shaped spring 60 which is secured at its rear depressed end by a screw 6|, or otherwise, to the top of the horn l8 while its front elevated end 62 is forked so .as to straddle the guide tube 51 and bear against the central parts of the underside of a longitudinally elongated head 63 arranged at the upper end of the guide tube 51.

Depression of the punch is effected positively by the downward movement of the ram. 9 which operates on the upper end of the punch,

Means are provided for adjusting the overall or operative length of the punch as a whole so as to properly locate the punch and bring the lower end of the punch bit in line with the lower end of the guide sleeve, or substantially so, when the punch is in its uppermost position. For this purpose adjusting means are provided for determim'ng the desired length of the punch when originally assembling the parts of the apparatus and also restoring the length of the punch as a whole after the same has been shortened by grinding the lower end for sharpening the same when-worn.

The specific means for lengthening or adjusting the length of the punch shown in Figs. 1, 2, 5 and 6 consist of a lower adjustable lifting screw" nut 64 applied to the upper screw threaded end of the punch body and an upper clamping screw nut or head 35 arranged on the screw of the punch body above the lifting nut. Spring means t are provided which operate on the underside of the lifting nut 64 and act to raise the punch after each perforating operation so that the lower end of the punch is flush, or substantially even, with the lower end of the guide sleeve 51 and thus permit the bit of the punch during its downward A assessend of the stripper sleeve which strips the workmovement under the pressure of the descending wear and the total length of the same is shortened upon resharpening of the bit the length of the punch is restored by loosening the clamping nut 65 and then unscrewing the lifting nut 64 until its underside is the required distance from the lower end of the bit after which the clamp-' ing nut is again tightened for holding the lifting nut in body.

The stripping means cooperate with the lifting spring 60 for removing the work from the punch of the perforating unit after the punch has pierced the work, which stripping means, as shown in Figs. 1 to 6, are constructed asfollows;

The numeral 85 representsan upper stripper head which is arranged above the lower lifting head 63 and the holder 26 and has the same blong form as this lower head, being comparative- 'plurality of punching units can be assembled close together side by side crosswise of the press;

as shown in Fig. 2. At the front and rear ends of the lower lifting head and the upper stripper head 85 the same are connected respectively by 1y long but narrower than the holder so that a I piece from the punch. During the downward \stroke of the mm the same engages the upper lock nut or head 65 of the punch and moves the latter together with the stripper mechanism downward as a unit until the lower end of the its adjusted position on the punch a linkage or loose connecting means consisting preferably of upright tie bolts 86, 8'! the-

lower ends

88, 89 of which are screw threaded and engage with threaded openings in the front and rear ends of the lower lifting head 63 while the upper ends of these bolts slidably engage openings 96, 9| in the front and rear ends of the upper stripper head 85 and are provided respectively with

heads

92, 93 which engage with the upper side of the front and rear ends of the upper stripper head 85, as shown in Figs. 1, 5 and 6. The body 55 of the punch is arranged midway between the front and

rear tie bolts

86, 81. and is not connected with the bar or head 85 but is slidable with that part thereof immediately below its lifting nut or member 64 through a non-threaded clearance opening '94 in the central part of the upper stripper head 85 and engages its lifting nut 64 with the upper side of this head, as shown in Figs. 1, 5 and 6, thereby permitting the punch to be freely removed from the stripping means by merely lifting the same out of the heads or

bars

63, 85 and the sleeve 51. I

The

numerals

95, 96 and 91 represent helical central, front and rear stripper springs which are interposed under an initial compression between the lower lifting head 63 and the upper stripper head 85 and surround, respectively, the body 55 of the punch and the from; and

rear tie bolts

86, 81. These springs are preferably of the same size and strength and when the same are expanded to the extent permitted by the linkage or tie

bolts

86, 81, the stripper head 85 and lifting head 63 are separated and the punch is lifted so that its lower or cutting end is flush with the lower end of the stripping and'guiding sleeve 51, or

substantially so.

when the ram 9 is iri'its highest position, as

stripper sleeve 5'! engages the upper side of the workpiece .resting on the die after which the stripper sleeve ceases its downward movement but the punch continues its downward movement and in cooperation 'withthe die punches a slug out of the workpiece and forms a hole therein which slug passes downwardly through the opening in the die. During this downward movement of the stripper sleeve the lifting spring 68 is deflected downwardly and during the downward movement of the punch independently of the strippersleeve the stripper springs are further compressed. During the subsequent upward stroke of the ram the punch first moves upwardly with the same while the stripper sleeve remains at restLami is held down by the strippersprings until the workpiece has been stripped from the punch and then the stripper sleeve and punch are lifted from the workpiece and from the die by the lifting spring 60, thereby leaving a clearance space between the die and the punch and stripper sleeve to facilitate removal, of the finished workpiece and its replacement by another workpiece.

If the workpiece to be perforated is very heavy and requires much power to strip the punch from the workpiece after the hole has been punched therein, then all three of the stripper springs 95, 96, 91 are employed, as shown in Fig. 1. If less power is required to strip the punch from the workpiece one of the strip'per'springs is omitted and for this purpose the central spring 95 is removed in order to keep the spring means of the stripper mechanism balanced. The removal of the central spring 95 for' this purpose can be accomplished quickly and easily by withdrawing the punch upwardly from the stripper sleeve 51 and the lower and upper heads 63, and replacing the same after the central spring has been removed, as shown in Fig. 6. If it is necessary to still further weaken the resistance of the stripper spring means, this can be done by employing only one stripper spring and for this purpose the central spring 95 is retained and the front and

rear springs

96, 91 are omitted, so as to still balance the spring means of the stripping mechanism, as shown in Fig. 5. Removal of the front and

rear springs

96, 91 for this purpose can be easily effected by first detaching the

tie bolts

86, 81 from the upper and lower heads 65, 68 of the stripper mechanism. I

It will be noted that when changing of the central spring 95 from one size or strength to a another is desired, this can be accomplished by merely lifting the punch 55 out of its guideways in the upper head 85, lower head 63 and guide sleeve 51 whereby the spring, is wholly free to be removed sidewise from between the heads 65 and 68 and thereafter another spring of the desired strength may be substituted in the same place and the punch may beslipped through the.

corresponding guideways in the heads 85 and 68 and the sleeve 51 for restoring the punching unit changeover.

of the punching apparatus while efiectingi this When punching a large number of holes in thick metal which requires more power than the press can deliver,'it is common practice to grind the lengths of the punchesto provide different times of penetration. When any punch contacts the material to be punched the working end of the punch penetrates into the metal an amount which depends upon the hardness of the metal before the pressure becomes too great for the metal to stand and at this pointthe slug breaks out of the metal and enters the die opening.

In mild steel this penetration is approximately one-third of the thickness. To illustrate: a punch will penetrate into three-sixteenths of an inch thick mild steel approximately one-sixteenth of an inch before the slug breaks out of the workpiece.

In order to punch more holes than can normally'be punched with a given power every second punch may be ground one-sixteenth of an inch shorter than its neighbor. Or the punches may be ground in steps over a greater range, for example, the first punch may be of full length, the second one-sixteenth of an inch shorter, the third one-sixteenth of an inch shorter than the second, and the fourth one-sixteenth of an inch shorter than the third.

It will therefore be aparent that the adjustability as to length of the punches in accordance with this invention permits of great latitude in this respect.

Means are provided for maintaining the strip ping mechanism in a posit on in which its

heads

83,,85 and row of

springs

95, 96, 91 are arranged in a vertical plane extending fore and aft of the press and thus render the punching unit comparatively narrow throughout its height to permit of assembling the same compactly transversely of the press. This is preferably accomplished by means of a vertical pilot. or guide pin 98 projecting downwardly from the lower end of the rear tie bolt 91 and sliding in a vertical guide opening 99 formed in the horn l8 in rear of the guide opening 58 for the stripping or guiding sleeve- 51. punch rise and fall the pilot pin 98 slides vertically in the guide opening but prevents the st ipping mechanism from turning laterally.

In the preferred construction the pilot pin of the spring elements for use in the organization asmay be best suited for doing work of a particular character. By making it possible to use different spring pressures in the stripper mechanism, the press can be relieved from depressing more stripper springs or elements than are necessary for stripping the work in hand. This is of particular importance in the case of apress in which several hundred punching units could be assembled- If, however, the press and the work in hand renders it impossible to punch, say 100 holes at the same time by the use of 800 stripper springs, then the spring resistance could be reduced one step by omitting the central stripper spring of each punching unit, making a total of 100 springs which are cut out. If the work in hand is still too heavy or the number of stripper units too great to permit of operating the press satisfactorily, then the resistance or pressure of the stripper spring means can be reduced another step by removing the front and rear stripper springs from the several units, making a total of 200 inactive springs. stripper springs to strip the work from the punches depends on a number of conditions, such as clearance between the punch and die of each unit, the kind of material which is being punched, and the thickness of this material. It therefore may be necessary in doing work of this character to punch fewer holes at one time if heavy stripper spring pressure is required. The springs of the stripper mechanism need only to be under suflicient compression while effecting the punching operation to subsequently strip the work from the punch and the latter only need be compressed enough togo through the work and thus make it easy on the stripper springs.

Figs. '7 to 10 show various other ways for ad justing and backing up the die to compensate for As the stripping mechanism and wear and sharpening of the upper end of Working face of the same. In Fig. 7 the die 38 is provided with a chute or discharge passage 42 which extends from the die opening 29 at the upper end of the die to the lower end of the same and communicates with a central opening 39 in a, backing up or supporting screw plug 40 working in a threaded opening 33 similar to the constructions shown in Fig. 1. Upon turning the plug 40 passes through an opening I00 in the leaf-shaped lifting spring 60 which latter has the front edge |0| of its opening arranged so close to the front side of the pilot pin that the latter is gripped by this edge l0l during the last part of the upward movement of the lifting spring and acts like a clutch to limit the upward movement of the stripper mechanism and the punch during the upward stroke of the ram. During the downward movement of the stripper mechanism with the ram and punch, the lifting spring is depressed and flattened so as 'to disengage the gripping edge ml of the lifting spring from the pilot and thereby avoid interfering with the free downward movement of the punch and stripper mechanism.

If-desired the stripper lifting spring may be of helical form, as'shown at I02 in Fig. 6, in which case this spring is placed around the pilot pin 98 and interposed between the underside of the lift- I permits of selecting a smaller or greater number in the proper direction the same will be raised for engaging the same with the lower end of the die and provide a firm support or backing up for the die after the latter has been sharpened and raised the requisite extent on the shoe of the holder. In this construction the slugs produced during the perforating operation pass downwardly through the die 38 and screw plug 40 to the underside of the press instead of beingdischarged toward, the front side of the press.

Instead of employing 'a screw plug for backing up or supporting the die, as shown in Figs. 1 and 7, the same result may be attained by fitting the lower end of the die 4| in a vertical guide opening 42 in the shoe l1 and backing up the die and v taking up for sharpening or wear by means of a screw nut 43 resting on the upper side of the shoe l1 and engaging with 'an external screw thread 44 on the die 4 I, as shown in Figs. 8 and 9. Fig. 8 shows the die 4| provided with a slug discharge chute 3I leading from the die opening 29 to the side of the die, as shown in Fig. 1, while in Fig. 9 the die 45 is provided with a slug discharge chute 42l extending from the die opening 29 to the lower end of the die and through the lower part of the opening 42 to the underside of the shoe l1.

The ability of the.

' said guide opening 41.

'tive position.

movable wedge rod 46 guided, in a guide opening.

41 in the shoe and provided with a bevel as at its inner end which engages with a corresponding bevel 48 on the lower end of the die 58, and a screw nut or sleeve 5| journaled on the outer end of said wedge rod between two shoulders 62, 53 thereon and engaging its external thread with an internal thread54 in the outer part of Upon turning the nut 5| in the proper direction the wedge rod 46 will be moved for engaging its bevel surfaces 48 with the bevel surface 48 of the die 58 and thereby support the die in its proper position.

For the purpose of taking up for sharpening of the die by the means shown in Fig. 10, after the face of the same has been ground on, the wedge rod 46 is first withdrawn by means of the screw in order to expose the lower end of the die 50 and permit of hitting the same with a tool through the lower end of the guide opening 28 g and raising this die the requisite extent after which the wedge rod 46 is re-engaged with the lower end of the die 50 for supporting or backing the same properly while in use.

Equivalent means are shown in Figs. 11 to 19 for adjusting the overall length of the punch and also the distance from the tip of its bit to its lifting surface. In Fig. 11 this is accomplished by means of a lifting screw nut 66 applied to'the upper screw threaded end of the punch body and a clamping screw or set screw 61 working in the upper part of-the lifting screw nut 66 and engaging with the upper end of the punch body. Upon loosening the set screw plug 61 the lifting.-

screw nut 66 may be unscrewed sufllciently to obtain the required distance between the lifting face on the underside of this screw nut and the lower end of the bit to compensate for the amount which has been removed from the bitfor sharpening purposes, after which the clamping screw plug is again tightened to hold the nut 66 in place. I

' A like effect is obtainable by the construction which is shown in Fig. 12 and which comprises a cap screw 68 applied to the upper screwthreaded end of the body '55 of the punch and a set screw or clamping screw 69 working in a threaded opening in the side of this cap screw and provided with a tapering inner end I0 which engages'with a correspondingly tapered upper end 1| on the" punch 'body. Upon loosening the set screw and turning the screw cap on the punch body, the distance between the underside of the screw cap and the lower end of the punch may be increased as much as required to maintain the lower end of the punch flush, when in its retracted position, with the underside of the guide sleeve, after which retightening of the set screw will hold the respective parts in their rela- The means for accomplishing this purpose shown in Fig. 13 consists of a screw cap 12 applied to the screw threaded upper end 13 of the punch body 55 and one or more spacing or adjusting slugs or washers l4 interposed between 16 by a screw joint with the punch body above this collar and placing a plurality of thin spacing or adjusting washers or slugs TI on the punch body underneath this collar. Before the punch is worn at its lower end-all of the washers 11 are placed on the punch body underneath the collar as shown in Fig. 14, so that the same will be supported on the upper head 85 of the stripping device, and as the lower end of the punch is ground oil for sharpening it, some of the washers 11 are transferred from that part of the punch below the collar 15 to that part of the punch body above this collar and under- 1 neath the bearing ring 16, as shown in Fig. 15,

thereby lowering the punch on the upper head 85 of the stripping device to bring the lower cutting end of the punch in line, or substantially so, with the underside of the guide sleeve 51.

If desired the punch body may lbe provided at its upper end with an .extemally screw threaded collar I8 which is swaged thereto, an internally threaded bearing cap 19 engaging 'with this threaded collar, and a plurality of movable washers 88 arranged on the punch body underneath the threaded collar, as shown in Fig. 16. As the lower end of the punch is ground oil for sharpening the same the punch is lowered by transferring washers from the punch body underneath the threaded collar 18 to the space between the upper side of this collar and the top of the screw cap 18, as shown in Fig. 17, thereby compensating for the stock removed from the cutting bit of the punch.

According to the

construction

18 and 19, a collar 8| of the punch body by swaging or otherwise, a thick ring 82 is adjustably secured to the upper end of the punch body by a set screw 83 and a plurality of thin adjusting washers 84 are mounted on the punch body below said collar. When the punch is first mounted the thick ring 82 is placed on the punch body immediately above the collar 8| and all the washers are placed on the punch body below the collar, as shown in Fig. 18. As the wear on the lower end of the punch bit necessitates sharpening and consequent shortening of the same, the punch body shown in Figs.

is lowered as a whole by transferring washers 84 the upper end of the punch body and the top from that part of the punch body 'below the collar 8| to that part of the body between the top of the collar and the bearing ring 82, as shown in Fig. 19.

All of the several means for adjusting the overallglength of the punch here shown are very simpl in construction, the same can be manipulated easily and quickly and they are of sturdy construction and not liable to get out of order under heavy duty.

In the several forms of this invention whereby the overall length of the punch, and particu-' larly the distance from its lower cutting edge to its lifting surface may be adjusted the several parts whereby this adjustment is eifected, when taken as a whole, may be regarded as a bearing or lifting head or element and is so taken in the wording of the appended claims.

'It will be noted from the drawings that the holder of each perforating unit is made very narrow throughout its height and that the several parts of the die, punch and stripping means associated therewith are also made correspondingly narrow and do not project laterally beyond the outline of the holder, thereby enabling a plurality of such perforating units to be assembled close together in a transverse row and is secured to the upperpart movable lengthwise thereon, a normally stationary die member mounted on said holder, a punch 1 member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, resilient means for moving said punch away from said die and the workpiece, and adjusting means for adjusting the relative position of said die -and punch members for bringing their cooperating parts in the proper cooperating position with other like units independently of said bed and ram. *2

2. In a'press having a bed and a ram movable toward and from the bed, multiple perforating units, each of said units comprising a holder which is adjutably mounted on said bed and movable lengthwise thereon, a normally stationary die member mounted on said holde a punch member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, [resilient means for moving said punch away from said die and the workpiece, and adjusting means for adjusting the relative position of said die and punch members for bringing their cooperating parts in the proper cooperating position with other like units independently of said had and ram, said adjusting means-including a screw mounted on said holder and adapted to bear against said die member and move the same toward said punchmember.

3. In a press having a bed and a ram movable toward and from the bed; multiple perforating units, each of said units comprising a holderwhich is adjustably mounted on said bed and movable lengthwise thereon, a normally stationary die member mounted on said holder, a punch member movably mounted on said holder and adapted 'to be moved by said ram toward said die member and the workpiece to be perforated,

resilient means for moving said punch away from said die and the workpiece, and adjusting means for adjusting the relative position of said die and punch members for bringing their cooperating parts in the proper cooperating position with other like units independently of said bed and ram, said adjusting means including a screw nut resting on said holder and having a thread connection with said die member whereby the latter will be moved toward said punch member upon turning said screw nut in the proper direction.

4. In a press having a \bed and a ram movable toward and from the bed, multiple perforating units, each of said units comprising a holder which is adjustably mounted on said bed and movable lengthwise thereon, a normally stationary die member mounted on said holder, a punch member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, resilient means for moving said punch away from said die and the workplace, and adjusting means for adjusting the relative position of said die and punch members for bringing their coop! crating parts in the proper cooperating position with-other like units independently of said bed and ram, said adjusting means including a wedg slidablymounted on said holder and engaging said die member whereby said die member will be moved toward said punch member upon moving the wedge in the proper direction.

5. In a press having a bed and a ram movable toward and from the bed, multiple perforating units, each of said units comprising a holder which is adjustably mounted on said bed and movable lengthwise thereon, a normally stationary die member mounted on said holder, a punch member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, resilient means for-moving said punch away from said die and the workpiece, and adjusting means for adjusting the relative position of said die and punch members for bringing their cooperating parts in the proper cooperating position with other like units independently of said bed and ram, said adjusting means including a head adjustable lengthwise on said punch member and and adapted to be shifted between said collar said die and the workpiece, and

adapted to be engaged by said ram.

6. In a press having a :bed and a ram toward and from the bed, multiple perforating units, each of said units comprising a holder which is adjustably mounted on said bed and movable lengthwise thereon, a normally stationary die member mounted on said holder, a punch member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, resilient means for moving said punch away from adjusting means for adjusting the relative position of said die and punch members for bringing their cooperating parts in the proper cooperating position with other like units independently of said bed and ram, said adjusting means including a collar fixed on said punch member, a'bearing head above said collar and adapted to be engaged by said ram, and washers adapted to be mounted on said punch member below said collar and to be shifted between said collar and bearing head 7. A perforating unit for use in connection with a press having a bed and a ram movable toward and from thebed, said perforating unit comprising a holder which is independent of said bed and ram and supported on said bed, a normally stationary die member mounted on said holder, a punch member movably mounted on said holder and adapted to be moved by said ram toward said die member and the workpiece to be perforated, resilient means for moving said punchaway from said die and the workpiece, and adjusting means for adjusting the relative position of said die and punch members for bringing their cooperatin parts in the proper cooperating position independently of said bed and ram, said adjusting means including a collar fixed on said punch member, a bearing head having a screw connection with said collar and adapted to be engaged by said ram, and washers mounted on the punch member below said collar and bearing head.

8. A perforating apparatus including a bed, a

ram movable toward and from the bed, and a plurality of perforating units each of which compri wit a socket, a die adjustable lengthwise in said socket for changing the position of the'face of movable a holder resting on the bed and provided the die, thread controlled means for retaining gaged by said'ram for moving the punch toward said die.

9. A perforating apparatus comprising a bolster, a plurality of unitary perforating units mounted in a row on said bolster and each unit including a punch and a die which are movable one toward and from the other for perforating and releasing a workpiece, and means for adju'sting the relative position of the punch and die of each unit so that the working place at which the cutting edges of the same cooperate may be maintained at a predetermined location and the working places of the punches and dies of the several perforating units may be all maintained in the desired relation 'to' avoid distorting the workpiece when punching and stripping pressure is applied thereto.

10. A hole punching device, comprising a unitary holder having a lower base and upper head, a perforating die mounted on said base, a punching and multiple spring stripping unit mounted and guided on said head and having at least one spring held in position by the punch in such manner that said spring may be removedor replaced by lifting said punch to permit such change. Y

v 11. A hole punching device, comprising a unitary holder having a lower base and upper head, a perforating die mounted on said base, a punching and multiple spring stripping unit mounted and guided on said head in such manner that the punching unit may be freely lifted from said upper head so that one of the plurality of pressure elements may be added to or removed from said unit.

12. In a punching apparatus for use between the bed and ram of a press, comprising a holder havin a lower base and an upper head, a perforating die mounted on said base, a punching device mounted and guided on said head as a punching unit, means for preventing said punching device from turning about on its axis including a pin extending downwardly from a lateral portion of said device and engaging said upper head.

13. In a punching apparatus for use between the bed and ram of a press, comprising a holder having a lower base and an upper head, a perforating die mounted on said base, a punching device mounted and guided on said head as a punching unit, means for preventing said punchin device from turning about its axis including a pin extending downwardly from a lateral portion of said device and engaging said upper head, and means for yieldingly maintaining said device in an elevated position when not engaged by said ram including resilient means interposed between said device and said upper head.

14. 1n a punching apparatus for use between the bed and ram of a press, comprising a holder having a lower base and an upper head, a perforating die mounted on said base, a punching device mounted and guided on said head as a punching unit, means for preventing said punching device from turning about its axis including a pin extendin downwardly from a lateral portion of said device and engaging said upper head, and means for yieldingly maintaining said device an elevated position when not engaged by said ram including resilient means interposed between said device and said upper head and surrounding said pin.

, 7 15. Ina pum .iing apparatus for use between the bed and ram of a press, comprising a. holder having a lower'base and an upper head, a perforating die mounted on said base, a punching devicemounted and guided on said head as a punching unit, means for preventing said punching device from turning about'its axis including a pin extending downwardly from a lateral portion of said device and engaging said upper head, and means for yieldingly maintaining said device in an elevated position when not engaged by said ram comprising a leaf spring attached to said upper head and bearing upwardly on said device.

16. In a pun'chingapparatus for use between the bed and ram of a press, comprising a holder having a lower base and an upper head, aperforating die mounted on said base, a punching device mounted and guided on said head as a punching unit, means for preventing said punching device from turning about its axis including a pin extending downwardly from a lateral portion of said device and engaging said upper head, means for yieldingly maintaining said device in an elevated position when not engagedby said ram comprising a leaf spring attached to said upper head and bearing upwardly on said device, and means for preventing the accidental separation of said device from said head comprising an opening in said leaf spring through which said pin projects, which opening is positioned to cause said spring to seize said pin when the de sired elevation of. said punchin device has been reached and thus limit the upward movement of the same.

17. In a punching apparatus for use between the bed and ram of a press, comprising aholder V having a lower base and an upper head, a perforating die mounted on said base, afloating punch guiding and stripping device including a sleeve the outer diameter of which slidably engages an opening in said upper head concentricwith said die and said sleeve having an opening which slidably engages a punch and guides the working end of the same die, and means for applying to said sleeve 9. resilient elevating eifect, resilient punch stripping effect, and anti revolving effect.

18. In a punching apparatus for use between the bed and ram of a press, comprising a holder having a lower base and an upper horn, a perforating die mounted on said base, a floating punch device including an upper bearing head, a sleeve slidably engaging its periphery with an opening in said upper horn, the interior of said sleeve slidably receiving a punch and guiding the working end ofthe latter concentrically into said die, and means for applying to said sleeve resilient elevating means, said sleeve being provided with a longitudinally extending lower head, resilient punch stripping means bearing on and interposed between the lower head and the upper bearing head, means for slidably connecting said upper head and said lower head, said upper head being provided with a punch accommodating opening in concentric relation with the opening in said punch guiding sleeve and a punch comprising a working end,

a a body, and an enlargement, said working end and body being guided in said sleeve and said enlargement bearing freely against the upper conc entrically into said .punchworkin .19. In a punching apparatus for use between v the bed and ram of a press, comprising a holder an upper horn, a perhaving a lower base and forating die mounted on said base, an upper bearing head, a floating punch guiding and strip ping device including a sleeve slidable with its periphery in an opening in said horn and adapted to slidably receive on'its interior a punch the working end of which is concentric with said die, resilient elevating means applied to said sleeve, said sleeve being provided with a longitudinally extending lower head, resilient punch stripping means interposedbetween the, top of said lower head and the upper bearing head, means for slidably connecting said upper head and lower head, said upper head being; provided with a punch accommodating opening in concentric relation with the opening said punch guiding sleeve, and a punch comprising a working end, body and enlargement, said working end and body being guided in said sleeve and said enlargement bearing freely against the upper face of said upper head to retain said end inside of said sleeve except when said ram depresses said working end into the material being worked upon, and means for preventing said device from revolving about its axis.

20. In a device comprising punch and stripper, means for restoring the over-all length of a punch, as .a whole, after the samehas been shortened by grinding, said means being confined to the punch, its head and adjustments so as to maintain the cutting edge of the punch in correct relation to the stripper.

21. In a device comprising punch and stripper, means for restoring the overall length of a punch, as a whole, after thesame has been shortened by grinding, said means being confined to the punch bit, unch body, head and adjustment so' as to maintain the cutting edge of the punch in correct relation to thestripper.

22. In a device comprising punch and stripper, means for adjusting the over-all length of a much, as a whole, and within itself, comprising a punch body, an adjustable head and means for locking said head in its desired position so as to maintain the cutting edge of the punch in correct relation to the stripper.

' 23. A erforating apparatus according to claim 19 containing' means for restoring the over-all length of the punch as a whole after the same has been shortened by grinding, including a punch body, an adjustable head, and'means for locking said head in its desired position on said body.

2.4. The herein described method of maintaining invertical relativepostions the cutting faces of the cutting elements of a plurality of perforating devices, each of which is a complete unit independent of other like units and has a die element and a punch element cooperating with the die element, said method consisting of placing any one of said die elements in its unit with its cutting face in the desiredhorizontal relation to the cutting faces of other die elements in other units, locking said elements in said position and adjusting the overall length of said punch element to cooperate properly with said die element.

25. The herein described method of maintaining in horizontally alined positions the cutting faces of the cutting elements of a plurality of perforating devices, each of which is a complete unit independent of other like units and has a die and a punch cooperating with the die, said method consisting in adjusting the overall length of any one of said punch elements to plac its cutting face in the desired horizontal position relative to the cutting faces of other punch elements in the other units.

26. A perforating apparatus comprising a holder, a die mounted on the lower part of said holder, a vertically movable punch mounted on the upper part of said holder, and stripping means including a plurality of resilient elements in a retainer arranged above said upper part whereby the punch is stripped from the 'workpiece and which is capable of variation in capacity by changing the number of springs in said container for adapting the stripping means to varying conditions.

27; A perforating appa'iatus comprising a holder, a die mounted on the lower part of said holder, a vertically movable punch mounted on the upper part of said holder, and means for stripping said punch from the workpiece including a plurality of springs in a floating punch carrier above said upper part, the number of which may be selected to suit varyingconditions.

28. A perforating apparatus comprising a holder, a die mounted on the lower part of said holder, a vertically movable punch mounted on the upper partof said holder, and means for stripping the punch from the workpiece includ- 1 ing a stripper sleeve which receives the lower tween the stripper sleeve and said member and capable of being selected as to n'umber for varying the stripping pressure to suit varying conditions.

29. A perforating apparatus comprising a holder, a die mounted on the lower part of said holder, a vertically. movable punch mounted onthe upper part of said holder, and means for stripping the punch from'the workpiece including a stripper sleeve which receives the lower part of said punch and which is guided on the upper part of the holder, a lifting member which receives the upper part of said punch, a plurality of stripper springs arranged between the stripper sleeve and said member and capable of being selected as to number for varying the stripping pressure to suit varying conditions, and tie means connecting said stripper sleeve and lifting member and operating to limit I the separation of the same.

30. A perforating apparatus comprising a holder, a die mounted on the lower part. of said holder, a vertically movable punch mounted on the upper part of said holder, and means for stripping the punch from the workpiece including a lifting member arranged on the upper part of said punch, a stripper sleeve which receives the lower part of said punch and is guided for vertical movement on the upper part of said holder, at lower head secured to said stripper sleeve, an upper head slidable on the punch and engaging with the lifting element thereon, tie members arranged on opposite sides of said punch and each connected at one end to one of said heads,' and slidable at its opposite end on the. other head, and spring surrounding said punch and tie members and interposed between said heads.

31. A perforating apparatus comprising a holder, a die mounted on the lower part of said I above the die and holder, a vertically movable punch mounted on the upper part of said holder, and means for stripping the punch from the workpiece includ ing a lifting member arranged on the upper part of said unch, a stripper sleeve which receives the lower part of said punch and is guided for vertical movement on the upper part of said holder, a lower head secured to said stripper sleeve, an upper head slidable on the punch and engaging with the lifting element thereon,

upright tie bolts arranged on opposite sides of said punch and each having a screw connection between its lower end and said lower head and having its upper end sliding on said upper; head .and provided with a stop engaging with the upper side of said upper head, and helical springs surrounding said punch and tie bolts and interposed between said lower and upper heads.

32. A perforating apparatus comprising aholder, a die mounted on the lower part of the holder, a vertically movable punch arranged cooperating with the latter, and stripping mechanism for removing the punch from th perforated workpiece including a stripping sleeve which receives the lower part of said punch and is slidable on the upper part of said holder, a lower oblong head arranged on the upper end of said sleeve, an upper oblong head slidable on said punch andoperatively engaging a lifting member thereon, said heads being parallel lengthwise with each other and with said holder, spring means interposed between said heads and holding them yieldingly apart, tie means connecting said heads and limiting their separation, and pilot means which permit vertical movement of said heads and sleeve same.

er, a die mounted on the lower part of the holder, a 'vertically movable punch arranged above the die and cooperating with the latter, and stripping mechanism for removing the punch from the perforated workpiece including a stripping sleeve which receives the lower part of said punch and is slidable on the upper part of said holder, a lower oblong head arranged on the upper end of said sleeve, an upper oblong head slidable on said punch and operatively engaging a lifting member thereon, said heads being parallel lengthwise with each other and with said holder, spring means interposed between said heads and holding them yieldingiy apart, tie means connecting said head and limiting their separation, and pilot means which'permit vertical movement of said heads and sleeve but prevent horizontal turning of the same, said pilot means including a vertical pilot pin projecting downwardly from a member of the tie means, and a guide opening arranged in the upper part of said holder and receiving said pilot pin. l v a 34. A perforating apparatus comprising a holder, a die mounted on the lower part of said holder, a verticallymovable punch cooperating with said die, and stripping means above said holder for removing the punch from the perforated workpiece including a tubular stripping sleeve which receives said punch and isguided on the upper part of said holder, and resilient 33. A perforating apparatus comprising a holdbut prevent horizontal turning of the lifting, means which operate to raise the stripper sleeve and also limit the upward movement of the same.

35. A perforating apparatus comprising a holder, a die mounted on the lower part of said holder, a vertically movable unch cooperating with said die, and stripping means for removing the punch. from the perforated workpiece including a stripping sleeve which receives said punch and is guided on holder, a head arranged on the upper end of said sleeve, stripper spring means interposed between said head and the upper part of said punch, a pilot pin projecting downwardly from said head and slidable in an opening in the upper part of said holder, and a leaf-shaped lifting spring secured at one end to said holder and provided at its other end with a fork which holder, ahead arranged on the upper end of said sleeve, stripper spring means interposed between said head and the upper part of said punch, a pilot pin projecting downwardly from said head and slidable in an opening in the upper part of said holder, and a leaf-shaped lifting spring secured at one end to said holder and provided at its other end with a fork which straddles said sleeve and bears against the underside of said head and said lifting spring being also provided with an opening which receives said pilot pin, and an edge of said opening being arranged to engage said pilot pin for arresting the upward movement of the same and the parts connected therewith.

37. An apparatus for perforating the flanges of a bar which is of angular form in cross section and which is rovided on the inner side of one of its ,flanges with a bead, comprising a die provided below its face with a recess for receiving the bead of the respective flange while the other flange of the same rests on the face of the adapted to perforate the last mentioned flange.

38. An apparatus for perforating the flanges of a bar which is tion and which is provided on the inner side of one of its flanges with a bead, comprising a die provided with a bearing face, a longitudinal opening forming a cutting edge on said face, a discharge chute extending laterally from said opening to the side of the die, and an undercut or recess formed on the die below its face and opposite the outer side of said chute, and a punch adapted to cooperate with the opening and cutting edge of said die, the face of said die being adapted to support one flange of said bar while the same is being perforated between the upper part of said of angular form in cross sec-