US1986036A - Perforating die and stripping mechanism therefor - Google Patents

Description

Jan. 1, 1935. L. v. WHisTLER 1,986,036

VPERFORATING DIE ANDSTRIPPI'NGMECHANIISII THEREFOR Filed Oct. 25, 1932 Patented Jan. 1', 1935 .rnnroaarmd- DIE AND s'mmrma MECH- ANISM THEREFOR- Lawrence V. Whistler, Kenmore, N. Y., assignor to S. B. Whistler 8; Sons, sine Buffalo, N. I, a I

corporation of New York Application October 25, 1932, Serial No. 639,447

2 Claims.

My invention relates to perforating dies and stripping mechanism therefor; also to the mannor of securing the same to metal working or other similar presses.

One of the objects of my invention is theprovision of perforating dies which are adiustably secured to press platens, such as the ram and bed members of a press, and in which new and novel means are provided for so securing them in any position in the areas of said platens.

Another object of my invention is the provision of novel means for retaining the female member of a set of perforating dies on a platen,

and to provide new and novel stripping means whereby sheet metal or other material perforated by the dies is stripped from the perforating punch or male members "-Another object ,of my invention is the provision of new and novel porforating punches and means for retaining them in position, said perforating punches'being conveniently removable from the press platen so that others may be substituted therefor.

Another object of the invention is the provision of a stripperelement on a perforating punch spring-retained in position by the use of;

a cushioning element adapted to be compressed,

' or more fully compressed, under operation of the press. I

A further object of my invention is the provision of punch elements adapted to be interchangeably secured to a press platen, each punch elementhaving a helical spring surrounding it within a cage having space-apart elements relatively movable, one of said spaced elements being secured to the punch element and the other maintained in position by means of said helical spring and suitable connector elements connecting said spaced-apart elements together.

A still further object of my vention is the provision of a stripper device detachably secured to a perforating punch and comprising a cage secured to said punch and extensible and contractible thereon, and a helical spring enclosed within said cage to normally hold the same in extended position and to permit of contracting said cage under pressure applied thereto during perforating action of 'the press.

A still further object of my invention is the provision of punch holders applied to a platen of a press, perforating punches interchangeably securable to the punch holders, and a. stripper device removably applied to the perforating punch in use.

With the above and other objects in v'et" to appear hereinafter, my invention consists in the novel features of construction and in the arrangement and combination of parts to be hereinafter described and more particularly pointed ES PATENT. OFFICE:

similar press, saidhplatens being equipped with.

perforating or punching dies and a stripper device representative of my invention.

Fig. 2 is a bottom plan view of a portion of the upper press platen so equipped. I

Fig. 3 is a central longitudinal section of my improved stripper device illustrated as a complete unit and detached from the perforating punch. I

Fig. 4 is a top plan view of said device.

Fig. 5 is a sectional view of a centering device used temporarily in connection with atemplet perforated to assure proper location on the platen of the female member of a pair of perforating dies.

platen, showing one of the material gages.

Reference being had to the drawing in detail,

the numeral 6 designates the upper platen of a metal-working or other similar press, and 7 the lower platen thereof. In each of these platens, I

parallel bolt retainer grooves 8 are formed; these being shown of T-formation, but they may be otherwise formed.

Secured to the under side of the upper platen is a punch holder or retainer 9 into which the male member or perforating punch 10 of a pair of perforating dies is secured. This punch holder or retainer is in the form of a bar 11 provided with a longitudinal slot 12 and having at oneend a head or enlargement 13 extending downwardly therefrom, said head being axially bored out, as

at 14, and having a counterbore or depression 15 Fig. 6 is a plan view of a portionof the lower in shape. In the drawing I have shown a perforating punch whose lower portion is somewhat reduced in diameter and of cylindrical formation so that it will serve to punch a, round opening of definite size in a sheet of metal or other material. This lower portion may, however, be reduced,- twice in diameter from its enlarged upper or securing Portion, and may also have its lower or punch end of any desired shape in cross section, depending onthe particular 'shapeof the opening to be punched in the material.

It will be apparent therefore that punches of various shapes and diameters are adapted to be used in connection with the punch holder or retainer 9; and in all instances'the punches used in said holder or retainer have their upper or securing portions of a shape and size conforming to the bore 14 of said holder 'or retainer while.

their lower portions may be varied and be of different diameters or thicknesses along their length *Y-shaped grooves while the shank portions of the bolts adjacent said heads are entered into the vertical, or narrow portions of said-grooves, the remaining portions of the shanks of said bolt or bolts being passed through the slot 12 in the punch holder or retainer. These bolts have nuts 17 applied thereto which bear against washers 18 placed against the punch holder or retainer. These punch holders or retainers may be adjusted lengthwise, or rotated on one of said bolts while sliding the other bolt in its retainer groove and varying the position thereof in the slot of the punch holder; or, when a single bolt is used, the punch holder may be rotated on the bolt so as to assume any angular position desired. In this manner a punch held within said punch holder or retainer may be positioned at any desired point within the area of the platen. In some instances the bar 11 is positioned at a right angleto the T-shaped grooves in the platen, in other instances parallel thereto, and it may be positioned at any desired. angle with respect to said T-shaped grooves.

Positioned within the counterbore or depression 15 of the punch holder or retainer is a hardened wearing plate 19, it being backed-up by the platen and being adapted to have the upper end of the perforating punch 10 bear thereagainst.

I Each perforating punch is notched, as at 20, the notch being of substantially V-formation and extending across the peripheral surface of the upper or securing portion. of the punch. Both walls ofeach notch are therefore obliquely disposed and into the head or enlargement 13 of the punch holder or retainer 9. securing screw 21 is threaded, a tapped screw opening being provided for said securing screw and extending from'the outer face of said head or enlargement inwardly obliquely to the bore 14 therein, the axis 'of said tapped screw opening being preferably parallel with one of the walls of the V-shaped notch in the perforating punch and at right angles to the other all thereof.

The securing screw 21 has its inner end por-- tion reduced in diameter, as at 22, and this reduced portion is smooth surfaced or unthreaded and adapted to be entered into the V-shaped notch of the punch so as to bear against the upper or contact wall portionof said notch. The

perforating punch is thus securely. held within the punch holder or retainer and can be quickly and easily removed therefrom when it is desired to replace it with another; it being simply necessary to unthread the screw 21 so as to cause the inner smooth surfaced end portion of registrars" to recede fully into the tapped screw opening in the head of the punch holder or retainer.

I preferably continue the diameter of the upper or securing portion of the punch downwardly a distance below the head or enlargement 13 of the punch holder or retainer and secure thereto a stripper device, designated as a whole by the numeral 23. This device is in the form of a cage and comprises an upper member or header 24, a lower member or header 25, a circular series of guides 26 on which said members are relatively movable towards and away from the other, and a helical spring or other cushioning element 27 interposed between said upper and lower members or headers and surrounded by said circular series 'of guides. The upper member or header 24, which may also be referred to as a securing member or header, has a radially-disposed tapped opening formed therein into which a securing screw 28 is threaded, which firmly bears against the perforating punch 10 axially entered in the upper member or header and securely fastens said member or header'to the punch. The said header is provided on its under side with a central downwardly-opening depression or pocket 29, and it is peripherally notched, as at 30, the notches extending from the upper face of said header downwardly to a plane within a short distance of the lower face thereof so as to provide stop lugs 31, for a purpose to presently appear, 30

said stop lugs forming the lower walls of said notches. These stop lugs are provided with smooth-surfaced bolt holes 32 and axially alined therewith are bolt holes 33 which are formed in the lower member or header 25 of the stripper 35 device. The guides 26 are in the form of rods, and more particularly considered, screw bolts having their heads normally entered in the notches 30 and bearing against the upper faces of the stop lugs 31 in the upper member or header, while their lower extremities are screw-threaded and entered into the tapped bolt holes 33 in the lower member or header 25. I

The helical spring 27 is interposed between the two members or headers, as stated, and surrounds the perforating punch, the upper end of this v spring being entered into the depression or pocket 29 in the upper member or header and it has its lower end bearing against the upper face of the lower member or header 25. The lower member or header 25 has an axial opening 34 therein into which, or through which, the lower or punch end of the perforating, punch is passed; the arrangement being preferably such that the punch end of said punch terminotes within said opening. Wabbling of the lower member or header 25 is therefore avoided, and

assurance of movement of said header in a perfectly vertical direction assured.

The helical spring is normally 'under slight 60 compression so as to exert pressure against the lowQr; member or header 25 of the stripperdevice and cause the heads of the guides orguide bolts 36 to bear against the lugs 31 of the upper member or header 24.

approximatesthat of or is of greater diameter than the head or enlargement 13 of the punch holder or retainer. For the purpose of increasing the accessibility of a tool to the securing screw 21, I find it of advantage to notch or cut away the head or enlargement 13 of the punch holder or retainer, as at 35, directly over a notch 20 in the upper member or head 24 of the stripper device, said notch or cut-away portion facing downwardly and outwardly.

A die retainer 36 isapplied to the lower platen '7 of the press and this comprises a bar 3'1 providedwith alongitudinal slot 38 and having at one end an upstanding head 39, cupped at its upperv endto receive a female die 40 provided with an axial opening 41, which is preferably' downwardly flared and the upper end of which is of a diameter or size and also of a shape to conform to the lower effective punch end-of the perforating punch 10. This upstanding head has an opening 42 extending from the female die 40 downwardly and outwardly to the side of the head so that material punched out of a sheet of metal or the like, designated by the numeral43 and lying upon the female die, may, be directed through said die and through said opening and be deposited on the lower platen, from which it may be removed, as and when desired.

Securing bolts 44 are entered into the T-shaped retainer. grooves of the lower platen in the manner in which the securing bolts 16 are entered into the bolt-retainer grooves of the upper platen, and these bolts are passed through the slot 38 of the die retainer. Nuts and washers forming part of said bolts serve to securely fasten the die retainer to the lower platen in the same manner as the nuts and washers 17 and 18, respectively, employed to secure the punch holder or retainer to the upper platen.

The sheet of metal or other material is positioned in contact-with one or more gages 45, one of which only is shown fastened to the lower platen and extends upwardly therefrom; but, if desired, these may be fastened to the upper platen and extend downwardly therefrom. These gages are spaced apart along at least one dimen-' sion of a platen and each comprises an angular structure having a horizontal arm 46, slotted as at 47, and a vertical arm 48, which is an upstanding arm in the application illustrated.

Securing bolts 49 are entered in the bolt-retaining grooves 8 of the lower platen in the same manner as the securing bolts 16 and 44, and these are passed through the slots in the horizontal arms 46 of the gages, washers and nuts forming part of such bolts being employed to tighten the gages to the platen.

By trending the T-shaped retainer grooves in one directionand in parallel relation, the perforating dies may be secured to the platens in co-axial alinement and at any desired points in the areas of said platens; the position of these dies depending on theexact location the perforations are to be formed in the sheet metal or other material to be punched or perforated.

Prior'to commencing the punching or per-,

forating operation it is necessary to ascertain the exact points of location of the die members on the platens, and this is accomplished by positioning the gages on one or the other of the platens and placing a tion-locating or centering openings therein against the gages. Preparatory thereto, however, the die retainer 36 is loosely positioned upon the lower platen, it'having been provided with a centering plug 50 shown in Fig. 5. This/plug is fitted into the upstanding head 39 of the die templet having small posiretainer and extending axially therefrom in an upward direction is a centering point 51 which is adapted to fit the small position-locating or centering opening of the templet. The die retainer isthen moved into such position on the platen that this centering point will be positioned in the opening of the templet while the latter is held against the gages, after which the bolts 44 ofthe die retainer are. tightened. The templet is centering plug from the die retainer, and the proper female die member inserted in the die retainer. .The male die or punch element, hereinafter referred to as the perforating punch, is then po- 15.

ated upon is inserted into the press to assume the position shown in Fig. 1, after which the upper platen is lowered to cause the stripper proper or lower member or surface of the material. This causes the spring 27 of the stripper device to be compressed and the guide bolts 26 to travel upwardly in theopenings 32 of the upper member or header 24 of thestripper device, the heads of said moving awayfrom the stop lugs 31 formed on said'uppe'r member or header. Simultaneously therewith the perforating punch 10 is lowered. and pressed through the metal or other material so as" to enter the female die member 40, with the die member and from the opening which it formed in the sheet metal or 0 her material, and as said punch becomes released from the sheet metal the stripper element 25 remains momentarily in contact with the metal under the expansive force then removed from the machine, the If) a): The sheet metal or other material to be operheader-25 to engage the upper 2,5

uide .bolts 9':

of thespring 2"luntil this force causes the guide bolts 26 to be moved to normal position with their heads in contact with the stop lugs 31, after which the continued upward movement of the upper platen of the ,press will cause said stripper element to be moved out of engagement with the sheet metal or othermaterial-so that this material, properly operated upon, can be freely withdrawn from themachine.

The stripper device, comprising the two head-' ers 24 and 25, the helical spring 2'1, bolts 26, therefore hold the sheet metal or other material being punched or perforated in contact" with the female die member, until after the punch is fully withdrawn from said material.

For the purpose of clearness I distinguish between the stripper deviceas an entirety and the a stripper or stripper element 25 in that I consider the element brought into direct and actual-contact with ,the material operated upon to be the stripper proper,-while this element associated with other parts form the complete stripper device, which is removable as a unit from the perforating punch.

when a hole larger or smaller is required than that which the perforating punch will make, or a hole which is of different formation, the perforating punch is removed from the punch holder or retainer 9 with the stripper device attached thereto; or if desired, the' stripper device maybe removed, from the perforating 75 and the guide" 5 in themes punch before removing the pimch from its holder or retainer. A new perforating punch con-.

certain elements of the same stripper device may be employed, as it will only be necessary that the lower member or header has an axial opening conforming to that of the lower or punch end of the substituted perforating punch. Replacement of the lower member or element of the stripper device can be easily accomplished by unthreading the guide bolts 26 from the tapped bolt holes 33 in the lower member or header of the device and then axially positioning another having a difierent axial opening and threading the guide bolts 26 into the tapped openings thereof.

While in the drawing I have shown a single set or pair of die members, it is to be understood that a plurality of such sets are oftentimes used,

and that therefore the drawing is merely representative of my invention and of the use thereof. It will be apparent that in my improved stripper device, the spring 27 is confined within an openwork housing or cage, and that in theevent of the spring becoming broken, it will not cause damage to the dies or the material worked upon, sime the broken portions of the spring will be wholly confined within the housing or cage, and retain its position around .the perforating punch, even though ineffective in maintaining the stripper proper under spring pressure.

Having thus described my invention, what I claim is: e

1. The combination of a punch retainer secured to a platen and having a cut-away portion facing downwardly and outwardly, a punch having one'end removably fitted in said retainer and having .a peripheral notch therein presenting faces at an angle to each other, said faces being 7 both disposed obliquely to the axis of said punch,

a'securing screw adjustable within said punch retainer and having its inner end entered in said peripheral notch and its outer end accessibleby' way of "said cut-away portion, and a stripper device surroimding the lower portion .of said punch and comprising an upper header secured to said punch directly beneath said punch retainer and having a peripheral notch in vertical alinement with the cut-away portion of said punch retainer, guide rods slidably fitted in said upper header ,and having enlargements normally bearing against said header, a lower header into which the lower ends of said guide rods are secured and having an axial opening into which the lower portion of said punch is slidably fitted, and a helical spring interposed between said headers around said punch.

2. A punch retainer having a cut-away portion facing downwardly and outwardly, a punchhaving one end fitted in said retainer and having a peripheral notchat said end, a securing screw threaded into said punch retainer and havingits inner end entered within said peripheral notch and its outer end accessible by way of said cutaway portion, and a stripper device applied to the projecting portion of said-punch and having a peripheral notch in vertical alinement with the cut-away portion of said punch retainer to permit access to said securing screw.

LAWRENCE V. WHISTLER.

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