US2019791A

US2019791A - Die, die holder, and ejector

Info

Publication number: US2019791A
Application number: US728710A
Authority: US
Inventors: Nelson Lester Warren
Original assignee: EDWARD L MONSON
Current assignee: EDWARD L MONSON
Priority date: 1934-06-02
Filing date: 1934-06-02
Publication date: 1935-11-05
Anticipated expiration: 1952-11-05

Description

1L. w. NELsoN 2,019,791

DIE, DIE HOLDER AND EJECTOR Filed June 2, 1934 2 Sheets-Sheet l n .'E. JNVENTOR. T9 LUJWISVH,

17M A mn A TT ORNE YS.

Nov. 5, 1935. ,`w, NELSON DIE, DIE HOLDER AND EJECTOR Filed June 2, 1934 2 Sheets-Sheet 2 A TTORNE YS.

. Patented Nov. 5, 1935 l UNITED STATES `2,019,791 lDIE, DIE HOLDER, AND EJECTOR Lester Warren Nelson, Bridgeport, Conn., assignor of one-half to Edward L. Monson, Bridgeport,

Conn.

Application' June 2, 1934, Serial No. 728,710 'l Claims. (Cl. 164-33) This invention relates to blanking and piercing dies, that is to say, to dies for stamping a iiat blank from a sheet of metal and ldies for punch- 'ing a hole through a blank.

For the sake of definiteness in'description, the term die will herein be used to denote the element on which the .metal sheet rests, said element having an opening therethrough of the same outline as the blank to be produced, and the term punch will be used to denote the element which is forced against the sheet and into the die to shear from the sheet a blank having the outline of the punch and die.

The general object of the'invention is to reduce the cost of the die and to obviate the necessity of providing a die set for each die.

Heretoiore it has been the practice to form the die of a relatively. thick piece of metal and to mount the die in a shoe having an opening therethrough toallow the blank to drop through the die and the shoe into a receptacle placed in position to receive the blank. The cost of forming an opening of the desired outline through such a heavy piece of metal is relatively great and the necessity of providing for each die aA shoe adapted to support the die and allow the blank'to pass through has added to the expense vof tooling up for the manufacture of a given part.

1 Fig. 5,15 a view of the' blank which ticular die herein shown is adapted to produce.

The present invention aims to reduce tool expense by forming the die of a relatively thin piece of metal and by supporting the die in a universal die holder. In order to prevent the relatively thin die from springing under thei pressure exerted by the punch, the holder is so constructed as to afford full support for the die during theeffectiveA (i. e. the shearing) portion of the punch stroke. For this purpose the support for the die extends clear across the opening in the die so as to support the die upto the outline of the opening in the die. Since thesupport for the die thus extends across the opening in the die, there is no opening in the support through which the blank may drop when severed from the sheet. Hence, I have provided means for ejecting the blank, as .will hereinafter appear.

In the accompanying drawings,

l Figure 1 is a plan view of a universal die holder, die and punch embodying the features of my invention, pneumatic means being employed to eject the blank.

Fig. 2 is an elevation of said apparatus.

Fig. 3 is a section on line 8-3 of Fig. 1.

Fig. 4 isfafragmental view of the die.v

the par- Fig. 6 is a plan view of an alternative construction of `my invention, wherein a mechanical or non-pneumatic ejector is employed.

Fig.r 7 is an elevation of the parts shown in Fig. 6.

Fig. 8 is a fragmental sectional view illustrating the ejector. f

Fig. 9 is a fragmental plan view of the ejecting mechanism.

Merely for the sake of clearness of understandl. ing, I have shown in Fig. 5 a blank A which' the particular die shown in Figs. 1 and 2 is adapted to produce, although it will, of course, be understood that blanks of a great variety of outline may be made by means of dies embodying the presll ent invention.

The die I has an opening 2 therethrough which i is of the outline of the blank A. The punch 3 has an exterior form corresponding to the form of the blank. The punch 3 is attached to a punch lo holder 4 ,adapted to be operated by the ram of a y punch press, the punch holder being guided in any usual or desired manner for accurate movement toward and away from the die holder 5. 'Ihe die holder isadapted to be secured in the ordi- II nary or any preferred manner to the bed of the punch press.

The die I may be of any suitable external form, being herein shown as oblong in form. In order that the die holder shall be capable of use with so various dies I contemplate that the dies shall all be of the same external form and dimen` The die holder 5 comprises a shoe 6 having a recess therein of the same width and length as 35 the standardized die I, said recess being indicated at 1 in Fig. 3. The recess 1 is of sucient depthto receive not only the die I but also a rest block 8, said rest block being'of approximately the same Width and length as thestandardized o die. 'Ihe upper surfaceof the rest block 8 is accuratelyground so as to provide a good seat for the die. The rest block has no4 perforation therein corresponding to theopening 2 of the die, but, on the contrary, extends clear across said opening so as to afford perfect support for the walls of the opening 2.

The walls of the opening 2 are tapered at an angle of about one degree s o as to provide clearance between the blank and the lower portion 50 of said wall, so that when the puncl descends through the sheet the blank shall drop onto the rest block 8 by its own weight.

In order to provide spacethrough which the blank may beejected, I provide means for supu* porting the die I in such a manner that it shall rest solidly upon the rest block 8 while thevblank is being sheared out of the sheet and shall be elevated above the rest block 8 after the blank has been produced so as to)provide space between the die and 'the rest block through which the blank may be ejected.

The die I is mounted for vertical movement on four guide studs 9 fixed in the shoe E', said studs extending through openings I8 (Fig. 4) in bronze bushings II. These bushings are pressed into holes broached in the die. The openings I8 are drilled with the aid of a drill jig after the die has been hardened in order to insure that there shall be no misalinement between the die and the punch.

Four studs I2 are guided for vertical movement in openings in the shoe 6 and the rest block 8, said studs being supported upon and normally urged upward by expansive springs I3. The studs I2 support two parallel bars I4 which lie in slots formed in the rest block 8 and which underlie the die I. When the punch 3 is forced against a sheet of metal lyingl upon the die I, the die is forced downwardly into contact with the rest block 8 against the pressure of the springs I3, but as soon as the blank has been severed from the sheet the springs I3 raise the die I into.v the normal position shown in Fig. 3, thus providing a space between the die I and the rest block 8 through which the blank may be ejected.

The means shown in Figs. 1 and 2 I or ejecting the blank utilizes compressed air to blow the.

blank horizontally out from under the die. Compressed air is supplied from any suitable source and is controlled by a valve (not shown) arranged to be automatically operated in the operation of the punch press, said valve releasing a predetermined amount of compressed air when the press ram is traveling upwardly. In Fig. 1, I5 is a tube connected to said valve to conduct compressed air to a duct I6 in the, die holder, said duct in turn communicating with a duct I1. The duct I1' is connected to the recess 'I opposite the space normally provided between the die I and the rest block 8 by means of ports I 8. 'I'hese ports are controlled by means of adjustable spring pressed valves I8. 'Ihe valves I9 provide means for adjusting the iiow O15-airl through the ports I8 in accordance with theform of ejector mechanism comprising an ejector slide 22 which is arranged to be reciprocated in vthe space between the die I and the rest block 8. The ejectorslide 22 is connected by means of a rivet L23 to a rack`24. Said rack meshes with a pinion 25 which is iixed to the lower end of a,

y; pin or shaft 26. 'I'he upper portion of the shaft 26 extends within a bushing or sleeve` 21 which -is secured to the punch holder 4*. In order to cause the shaft 26 to turn as the-punch holder Im is reciprocated,I provide a connection between said parts comprising two bearing balls ,28 mountedv in recesses in the bushing 2I and extending into spiral grooves 29 in the 'shaft' 26. As the punch holder 4a is reciprocateds the shaft 26 will be revolved to reciprocate the ejector slide. 22. 1

By reference to Fig. 8, it will be noted that the forward end 30 of the ejector slide 22 is turned upwardly and that the forward end of the slide 5 retainer cover 3| is beveled, thus providing a spacel 32 between the front end of the ejector slide and the front end of the slidecover plate. In piercing operations a small slug may drop after the ejector has been advanced across the die plate, and if this occurs the slug will be received in the space 32 on the ejector slide and will be withdrawn frombetween the die and the rest block as the ejector slide returns to the normal position-shown in Fig. 8, thus insuring that 15 there shall be nothing between the die and the rest block when the die is again forced down.

It will be evident that by making the dies to standard outside dimensions, the die holder herein shown may be used for any number of dies. 20 The dies may be made of relatively thin stock, as for example, three-eighths of an inch thick, and thus may be produced much more economically than has been possible in the prior art. -Notwithstandingthethinness of the die, it may be 25 used in the production of blanks from relatively heavy stock, since the die rests flrmly upon a substantial flat element, namely, the rest block 8.

While the drawings show a blanking die, it will be apparent that the invention is capable of use 30 in connection with piercing dies and blank pierce y follow dies.

One of the advantages of the present construction is that a change from one die to another may be made in a relatively short time, since the die'35 I and the punch 3 may be quickly removed and another pair substituted without any adjustment of the die holder or the punch holder.

While I have described the construction herein shown with considerable particularity, it will be 40,

. blank to be formed, a reciprocatory punch, a rest block for supporting the die at the walls ol.' said 5o opening during the effective portion of the stroke of the punch, means for normally supporting the die at a distance above the rest block to provide a laterally-extending space between the die and the rest block through which the blank produced 55 by the punch and die may be laterally removed, said means yielding under the pressure exerted upon the die by the punch to allow the die to descend into contact with the rest block, and means for accurately guiding the die in its movements toward and away from the rest block.

2. In a die mechanism, the combination of a supporting element having a recess therein; a relatively thin die of standardized external form in said recess, said die having an opening therethrough to receive a cooperating punch element.

a rest block in said recess below the die, means for, normally supporting the die at a distance above the rest block, said means yielding under 'the pressure exerted upon the die 1n the punch- 70 ing operation toallow thedie to descend to contact with the rest block for the effective portion of a punch stroke, said supporting means4 comprising two parallel bars extending in slots in the rest block and underlying 'the die, and springs 75.1,

underlying the bars and tending to raise the latter, and means for ejectlng a blank'horizontally out through the space between the die and the rest block.

3. In a die mechanism, the combination of a die having an opening therethrough to receive a cooperating punch element, a rest block below the die, means for normally supporting the die at a distance above the rest block, said means yielding under the pressure exerted upon the die in the punching operation to allow the die to descend to contact with the rest block for the effective portion of a punch stroke, and means for ejecting a blank through the space between the die and the rest block, said electing means comprising an ejector slide arranged to be reciprocated in the space between the slide and the rest block.

4. In a die and die-holder, the combination,

with a universal supporting element having a re- Y cess of standardized form and size to receive interchangeable relatively thin die-plates of standardized external form and size corresponding to said recess, of such'a die located in said recess and having a. die opening therethrough, the shape of whichopening determines the outline of the blank that is to be sheared from a sheet by a cooperating punch element, a rest block in said. recess below the die for supporting the die at the walls of said opening, and means for normally supporting the die at adiStance above the-rest block t'o provide a laterally extending space between the die and the rest block through which the blank may be laterally removed, said means yielding under the pressure exerted uporfthe die by. the punch element in operation to allow the die to bear against the rest block during the shearing operation.

5. In a die mechanism, the combination or a die, a coacting reciprocatory punch, a rest block below the die, means for normally supporting the die at a distance above the rest block, said means yielding under the pressure exerted `upon the die in the downward stroke of the punch to allow the die to descend and bear against the rest block during the eilective portion of the downward stroke, and means operating in timed relation with the upward stroke of the punch for laterally ejecting the blank through the space between the 5 die and the rest block.

6. In a die mechanism, the combination of a relatively thin die having an opening therethrough the shape of which opening determines the outline-of the blank to be formed by a co- 10 operating punch element, a rest block below the die for supporting the die at the walls of said opening during the effective portion of the punch stroke, and means for normally supporting the die at a distance above the rest block to provide a 15 laterally-extending space between the die and.

the rest block through which the blank produced by the die may be laterally removed, said means yielding under the pressure exerted upon the die in operation to allow the die to approach the rest 20 block during the preliminary portion of the punch stroke and to bear against the rest block during the effective portion of the punch stroke.

7. In a die mechanism, the combination of a die having an opening therethrough the shape of 25 which opening determines the outline of the blank to be formed by a cooperating punch element, said die having a plane lower side, a rest block below the die, for supporting the die at the walls 30.

of said opening in the punching operation, said rest block having a plane upper side against which the plane lower side of the die bears during the eiective portion `of the punching operation, means for normally supporting the die at a disas tance above the rest block, the die in the punching operation descending to contact `:.ith the rest block for the effective portion of a punch stroke, and means for ejecting a blank through the space normally provided between the die and the rest mock. s 40 LESTER WARREN NELSON.