US2109854A - Thin sheet blanking mechanism - Google Patents

Description

Patented Mar. 1, 1938 UNITED STATES PATENT OFFICE THIN SHEET B LANKING I MECHANISM Isaac L, Wilcox, Fulton, N. Y., assignor to Oswegb Falls Corporation, Fulton, N. Y., acorporatlon of New York This invention relates to cutting mechanism for forming blanks of thin sheet material. More particularly, the invention is a cutting mechanism particularly adapted to operate upon sheet material which is exceptionally thin, and which has the characteristic of possessing exceptionally high tensile strength until the sheet has been punctured, or ruptured, and which sheet possesses the further characteristic of being particularly relosistant to being cut or sheared. These characteristics of the material make it exceedingly difficult to cut or blank with the conventional punch and die structure. Certain cellulose materials possess this characteristic, For example, Cello- 15 phane.

Insofar as I am aware, the only practical method employed at the present time for forming blanks of such material is to employ a rotating knife. That is, the material is first cut into 20 sheets of approximately the size of the blank, and

, several of these sheets are arranged in stack formation and while so positioned, a rotating knife is moved into engagement with the stack, and the blanks are cut by the circular'motion of the knife. 25 While this method is practical, insofar as the severance of the blanks from the material is concerned, it is impractical in that the severed blanks of this exceedingly thin and slippery material must be subsequently handled individually during 30 the conversion of the blank into the article for which the blank is intended.

The general object of'my invention is a cutting mechanism of particularly economical construction and which, because of its novel struc- 35 ture, will efllciently sever individual blanks from the sheet material, and which operates to sever a large volume of blanks without the necessity of resharpening or replacing the cutting blade.

Another object ofthe invention is a cutting 40 mechanism for forming blanks of such material, which mechanism is so constructed that it is adapted for use on the blank converting machine, such as shown in my cqpending application, Sr. No. 105,411 filed October 13, 1936, thereby avoiding the necessity of manually, or otherwise, handling the blank after it has been severed from the sheet.

The invention consists in the novel features and 50 in the combinations and constructions hereinafter described and claimed.

In describing this invention, reference is had to the accompanying drawing in which like characters designate corresponding parts in all the 55 views.

Figure 1 is a partial plan view of the cutting mechanism. 1

Figure 2 is a cross sectional view.

Figure 3 is a fragmentary, enlarged cross sectional view. f 5 Figure 4 is a fragmentary elevational view of the cutting blade.

The invention comprises generally, a die member of annular formation adapted to support the sheet, and being provided with an aperture complemental to the contour of the blank, a cutter support, said die and support being arranged to have relative axial movement, a blade detachably secured to said support and extending therefrom toward the die, the extending edge of the blade being provided with a plurality of teeth arranged, upon contact of the blade with the sheet, to penetrate the sheet at a plurality of points, and to subsequently sever the sheet intermediate the penetrations.

The mechanism here shown is used to sever a blank in the form of a disk from sheet material, and comprises a die member In and a cutter support 'I I. The die and support are arranged to have relative axial movement. As here shown, the die support III is intended to be mounted upon a stationary part of the machine, and is provided with diametrically opposed. bosses l2, in which bushings l3 are inserted. The support II is provided with similar bosses ll in which are secured guide pins l5 which are slidably mounted in the bushings l3 and which are connected at their lower end to connecting rods l6 associated with the movable mechanism of the machine. Insofar as this invention is concerned, any conventional mechanism may be'employed to effect relative axial movement between the die it and the support H, or to move the support ll axially of the die "I. 4

The die is provided with a centrally arranged 40 aperture I1, and the support H with a similar aperture It. The under side of the support I I is formed with a counterbore arranged concentrically of the aperture l8, and in which is mounted a circular cutter blade 20 which is preferably formed of thin, flexible steel. The blade 20 may be of annular formation, or it may consist of a flat blade bent into circular form. The blade 20 is detachably secured in the counterbore of the support II by an expansible ring 2|, here shown as being split at one side as at 22, and being expanded by a tapered pin 23. The ring 2| is expanded to press the blade 20 radially outwardly against the counterbore in the support II, and the blade is thus rigidly but detachably secured to the support, and extends downwardly from the support toward the suHace of the die III. I

A presser member 24, in the nature of a ring,

encircles the blade 20 and is carried by one or more studs 25 slidably mounted in the support I I. The presser ring 24 is urged outwardly by helical compression springs 23 encircling the studs 23, and the arrangement is such that normally, or when the die I0, support ii, are in spaced apart relationship, the presser ring 24 encircles the lower edge of the blade 20 and extends downwardly a short distance therefrom.

The presser ring 24 may be formed with an annular rib 21 on its under side adjacent the bore of the ring, as shown in Figure 3, and the face of the die toward the upper side of a wear ring 23 formed with a complemental annular recess 28. As the support II is moved toward the die III, the rib 21 contacts the sheet 30 press-.- ingthe same into the recess 29. This action tends to draw the sheet taut, and it is held in this condition by being clamped between the presser ring 24 and the wear ring 23 of the die. Upon further downward movement of the blade carrier ii, the blank is severed from the sheet.

The lower or extending edge-of the blade 20 is formed with a plurality of teeth 32. The teeth 32 resemble generally the teeth of a saw, and are formed or arranged with the points 33 of the teeth extending in the same direction. That is, the forward side 34 of the teeth extend in angular relationship to the axis of the blade, and the rear side 33 extends at an appreciably greater angle, whereby the points 33 of the teeth are arranged to one side of the perpendicular drawn from the base of the teeth.

The hardened wear ring 28 is of such dimensions as to receive the toothed edge of the blade 20 upon movement of the support towards the die. The presser ring 24 engages the sheet and clamps the marginal portion of the same against the ring 28, as above described. Uponfurther movement of the support, the ends 33 of the teeth puncture or penetrate the sheet, and upon further-movement of the support and blade 20, the knife edges 35 of the teeth sever the sheet intermediate the penetrations. Due to the fact that the points 33 of the teeth extend forwardly of the base of the teeth, the sheet is completely severed between the penetrations.

. Due tothe fact that the blade initially only penetrates the sheet with the sharp points 33 of the teeth, very little pressure is established between the support and the die, with the result that the cutting mechanism may be of comparatively light construction and require little power for operation. With these advantages, the cutting mechanism is adapted to be incorporated in the blank converting machine. Attention is particularly called to the fact that with this mechanism, both the dle and the support i I may be of annular formation permitting the entire interior of the die and support to be open for subsequent operation of mechanism employed in converting the blank into the desired article.

- What I claim is:

1. Cutting mechanism for forming blanks of thin sheet material comprising a die member adapted to support the sheet and being provided with a centrally arranged aperture to receive the severed blank,za cutter support, said die and said support being arranged to have relative axial movement, a. cutter carried by said support and extending therefrom towards said die member, a presser member encircling said cutter and being slidably mounted on said support and bein! Operable upon movement of said support toward the die to press the marginal portion of the sheet against the face of the die, said cutter blade being formed on its extending edge with a plurality of teeth arranged to penetrate the sheet at a plurality of points upon contact of the blade with the sheet, and to subsequently sever the sheet intermediate said penetrations. 4

2. Cutting mechanism for forming blanks of thin sheet material comprising a die member adapted to support the sheet and being provided with a centrally arranged aperture, a support member movable axially toward and from said diemember, a presser member arranged intermediate saici'die member and said support and being slidably mounted on said support and being operable upon movement of said support toward the die to press the marginal portion of the sheet against the face of the die, a cutter blade carried by said support and extending toward said die, said extending portion being encircled by said presser member and the edge of the blade being formed with a plurality of teeth arranged to penetrate the sheet at a plurality of points upon contact of the blade with the sheet and upon further movement of the blade toward the die to sever the sheet intermediate said penetrations.

3. Cutting mechanism for forming blanks of thin sheet material comprising a die member adapted to support the sheet and being provided with a centrally arranged aperture, a cutter support, said die and support being arranged to have relative axial movement, a cutter carried by said support and extending therefrom toward said die member and being formed with a plurality of teeth arranged, upon contact of the cutter with the sheet, to penetrate said sheet at a plurality of points, and to subsequently sever the sheet intermediate said penetrations, and means carried by said support and cooperable with the die member to draw the sheet radially and maintain the same in taut condition during the penetration and severance of the sheet.

4. Cutting mechanism for forming blanks of thin sheet material comprising a stationary member of annular formation adapted tosupport the sheet during the cutting operation, a movable member of annular formation, a cutter blade detachably secured to the movable member and extending therefrom toward said stationary member, the extending edge of said blade being formed with saw-like teeth, with the cutting pointv of each tooth overlapping the base of the adjacent tooth.

5. Cutting mechanism for forming blanks of thin sheet material comprising a die member of annular formation adapted to support the blank during the cutting operation, a cutter carrier of annular formation arranged concentrically with said die member and being movable toward and from the same, said carrier member being formed with a counterbore, a cutter blade of thin, flexible material detachably secured in said counterbore and extending toward said die, said extending portion of the cutter blade being provided with a plurality of saw-like teeth, with the point of each tooth arranged to overlap the base of the adjacent tooth.

6. A cutting mechanism for forming blanks of thin sheet material comprising an annular die member, an annular cutter member provided with saw-like teeth extending toward said die member, said members having relative axial movement, the teeth of the cutter member being formed with the front and rear side edges thereof extending in the same direction, and with the rear edge of each tooth overlapping the point of the adjacent tooth, whereby upon relative axial movement of said members, the points of the teeth penetrate the sheet and subsequently the rear edges of the teeth sever the sheet interme diate said penetrations.

7. A cutting mechanism for forming blanks of thin sheet material comprising an annular die member, an annular cutter member, provided with saw-like teeth extending toward said die member, with the cutting point of each tooth overlapping the base of an adjacent tooth, and said annular members having relative axial movement to bring said teeth and die into and out of operative shearing relation.

8. A cutting mechanism for forming blanks of thin sheet material comprising an annular die member, an annular cutter carrier formed with a counter-bore, a cutter blade of thin, flexible material arranged in said counterbore and having a toothed edge extending toward said die member,

tive axial movement to bring said cutter blade and die into and out of-operative shearing relation, a ring member arranged in said counterbore within said cutter blade, and means operable to expand said ring to press said cutter blade radially outwardly against the wall of said counterbore.

9. A cutting mechanism for forming blanks of thin sheet material comprising an annular die member, an annular cutter carrier provided with saw-like teeth extending toward said die member, a presser ring arranged intermediate said die member and said cutter carrier member and being yieldingly supported by one of said members, said members having relative axial movement to bring the cutter member and the die into and out of operative shearing relation, said presser member being yieldingly carried by one ISAAC L. WILCOX.

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