US2276684A - Apparatus for forming metal closures - Google Patents

Description

March 17, 1942. c, BELLG 2,276,684

APPARATUS FOR FORMING METAL CLOSURES Filed June 15, 1939 2 Sheets-Sheet l Lie- , 4 2 24 mil? Z5 & 26

,llll 2 INVENTOR.

6.17. BELLG ATTOR S.

March 17, 1942. 7 c. M. B LLS v 2,276,684

APPARATUS FOR FORMING METAL CLOSURES Filed June 15, 1939 I 2 Sheets-Shet 2 INVENTOR,

6'. M BELLG.

1 A TTOR 5.

Patented Mar. 17, 1942 APPARATUS FOR FORMING METAL CLOSURE S Charles M. Bellg, Pitman, N. 1., assignor to Owens-Illinois Glass Company, a corporation of Qhio Application June 15, 1939, Serial No. 279,289

4 Ciaims.

The present invention relates to an apparatus for forming metal closures, particularly metal closures of the type having a skirt portion provided with an inturned lower edge and inwardly directed lugs which, when the closures are assembled upon the articles they are intended to seal, are hidden or substantially hidden from view.

It is an object of the invention to provide an apparatus for producing such closures by means of which, in a single pressing operation, an ordinary cylindrical blank is converted into a completed closure having an inturned edge and locking lugs.

Another object of the invention is to provide such an apparatus utilizing a series of separate die elements that, in a single pressing operation, successively operate upon the blank with each die element performing its own separate and distinct function and contributing to shaping the same to final form.

Toward these ends, the invention contemplates the provision in a die assembly of a series of separate, yet cooperating, die elements including an outer combined centering and forming ring which first engages the blank and centers the same while at the same time imparting to porticns of the rim other than those portions which form the locking lugs an initial inward bend; an inner secondary forming ring concentric with the outer ring which secondly engages the previously inwardly bent portions of the rim and folds or bends the same further inwardly, incidentally drawing the lug portions of the rim inwardly a short distance by the positive inward bending f of the other portions; and an intermediate lug forming ring concentric with the other rings which lastly engages the inwardly drawn lug portions of the rim and presses the same inwardly and downwardly to impart final shape Fig. l is a side elevational view, schematic in its representation, of a standard press on which the improved die assembly is mounted;

Fig. 2 is a vertical sectional view taken through the die assembly substantially along the planes indicated by the line 2-2 of Figs. Band 4;

Fig. 3 is a sectional plan view taken substantially along the line 3-3 of Fig. 2;

Fig. 4 is a sectional plan View taken substantially along the line 4-4 of Fig. 2;

Fig. 5 is a sectional view taken substantially along the line 5-5 of Fig. 2;

Fig. 6 is a side elevational View of the outer combined centering and forming ring;

Fig. 7 is a side elevational view of the inner forming ring;

Fig. 8 is a side elevational view of the intermediate lug-forming ring;

Fig. 9 is a fragmentary detail sectional view taken substantially along the line 9-2 of Fig. 4;

Fig. 10 is a fragmentary detail sectional View similar to Fig. 9 with the parts in a different position;

Fig. 11 is a fragmentary'detail sectional view taken substantially along the line H-H of Fig. 5;

Fig; 12 is a fragmentary vertical sectional view taken through a blank after the initial bend has been applied to the rim thereof by the outer ring of Fig. 6;

Fig. 13 is a sectional view similar to Fig. 12 showing the blank prior to completion of the bend or fold by the inner ring of Fig. 7;

Fig. 14 is a similar sectional View showing the blank after the bend has been completed by the inner ring of Fig. 7;

Fig. 15 is a fragmentary bottom plan view of a completed closure in the vicinity of one of the locking lugs;

Fig. 16 is a sectional view taken substantially along the line Iiiof Fig. 15; and

Fig. 17 is a sectional view taken substantially along the line il-Il of Fig. 16.

Referring now to Fig. 1, the invention is illustrated in connection with a conventional press including a base til or bed having associated therewith a guide H at one end and an actuating cylinder 52 at the other. A cross-head l3 overlies the bed 563 and has secured thereto a guide rod M which extends through the guide I I. A piston rod i5 also secured to the cross head 53 extends into the cylinder !2 and is attached to a piston (not shown) or other actuating mechanism, by means of which the cross-head I3 is reciprocated and on each of its down strokes is given a positive impulse. The .die assembly 16 comprising the invention is suspended from the cross-head l3 medially thereof.

In the bed Hi there is mounted a cupshaped die H or pad for receiving and retaining the metal closure blank B comprising a crown and an annular flange, the blank being disposed in an inverted position with the crown resting on the bottom of the cavity of the die I! and the flange being partially confined by the sidewalls of the die cavity.

Referring now to Figs. 2 to 5 inclusive, the die assembly l6 includes a hollow cylindrical die holder N3, the upper end of which passes through the cross-head l3 and which is secured thereto on opposite sides thereof by means of a clamp.- ing nut l9 and a spanner nut 20, both nuts being threadedly received on the holder. By loosening one nut and tightening the other, the elevation of the holder l8 may be adjusted vertically. The lower end of the die holder I8 is formed with an annular flange 2| to the underneath side of which there is secured by means of studs 22 an intermediate lug-forming die 23 or ring.

Referring additionally to Fig. 8, the intermediate lug-forming die ring 23 includes a flange portion 24 through which the clamping studs 22 extend and a sleeve portion 25, from which latter portion there projects downwardly a plurality of equally paced lug-forming fingers 26 corresponding in number to the number of lugs that are to be formed in the completed closure. The fingers 26 are each formed with a forming recess a therein which, when the ring 23 descends upon the blank B in a manner to be set forth presently, fits over one of the partially formed lugs as shown in Fig. 11 and imparts final shape to the same. In the present instance, since for illustrative purposes four such lugs are formed in the completed closure, four such fingers 26 depend from the sleeve portion 25 of the lugforming ring 23. A plurality of apertures 2'! (see also Fig. 3) is formed in the flange 2| of the die holder I8 and a similar series of apertures 28 of slightly smaller diameters is formed in the flange portion 24 of the lug-forming ring 23 and register with the former apertures 21.

The outer combined centering and forming ring 29 or die (Figs. 2 and 6) is telescopically received over the sleeve portion 25 of the ring 23 and is formed with inwardly extending forming lugs 30 that enter between the spaced forming fingers 25. The forming lugs 30 are arcuate in shape and are formed with curved inner walls or surfaces b and an upwardly and inwardly inclined forming shoulder c (Fig. 9) designed to engage the rim of the blankB when the ring 29 has descended upon the bed or base ID as shown in Fig. to impart an initial inward bend to the rim as will be set forth presently. The ring 29 is suspended from the flange portion 24 of the intermediate ring 23 by means of guide bolts 3|, the lower ends of which are threadedly received in the ring 30, the shank portions of which extend through the apertures 28, and the head portions of which are concealed in the apertures 21 and rest upon the upper surface of the flange 24.

The length of the shank portions of the guide bolts 3| is greater than the width of the flange 24 and thus the outer centering and forming ring 29 is maintained spaced below the flange 24 when the cross-head I3 is in its elevated position. A flat ring 32 or washer is supported on the upper surface of the flange 24 overlying the head portions of the guide bolts 3| and a resilient compressible sleeve 33 formed of rubber or other yieldable material is seated upon the washer 32. A second washer 34 resting on the sleeve 33 maintains the latter under a predetermined degree of compression by means of a spanner nut 35 threadedly received on the spanner nut 20. A set screw 36 maintains the nut 34 in any desired adjusted position. From the above description of parts, it will be seen that the centering and forming ring 29 is maintained spaced from the flange 24 but is capable of moving upwardly on the sleeve portion 25 of the ring 23, thus lifting the washer 32 from its seat on the flange 24 and compressing the resilient sleeve 33.

Referring now to Figs. 2 and 7, the inner forming ring 40' is nested within the intermediate ring 23 and includes a head portion 4| that seats within a recess 42 formed in the former ring 23,

.and a sleeve portion 43 from which there'depends a plurality of arcuate forming tines 44 that enter into the spaces existing between the forming fingers 23 of the ring 23 just inside the forming lugs 30 of the outer ring 29. As illustrated in Figs. 9 and 10 and as will be set forth more fully presently, the forming tines 44 are formed with arcuate shoulders d that are designed to engage the initially inwardly bent rim of the blank B and fold the same fully inwardly as the die assembly descends onto the base or bed l0.

The die assembly I6 is provided with means for stripping the formed closures from combined centering and forming ring 29 as the die assembly is elevated after each forming operation. Accordingly, a stripping mandrel 45 extends through the inner forming ring 40 and normally projects below the same and is slidable therein and also projects below the intermediate and outer rings 23 and 29 respectively. The lower end of the mandrel 45 is formed with a foot 46 adapted to bear against the inner surface of the closure crown when the die assembly is in its lowermost position. The mandrel is yieldingly maintained in its extended position as shown in Fig. 2 by means of a coil spring 41 which bears at its upper end against a plug 48 threaded into the upper end of the holder I8. The lower end of the spring bears against a head 49 which is secured by means of a stud 50 to the upper end of the mandrel. In order to break any vacuum existing between the foot 46 of the stripping mandrel 45 and the crown of the closure and efiect final stripping of the closure from the stripping mandrel itself, a stripping plunger 5| projects outwardly from the foot 46 and is normally and yieldingly held against retraction into the mandrel 45 by means of a coil spring 52 that bears at one end against the stud 50 and at the other end against the plunger itself.

Operation of the apparatus In the operation of the apparatus, a blank B is placed within the cup-shaped die H as shown in Fig. 2 and the cross-head and die assembly are caused to descend upon the bed or base ID in the usual manner of performing pressing operations. The outer combined confining and forming ring 29 moves into contact with the blank B and moves telescopically thereover with the confining walls b engaging the outer wall of the skirt portion of the blank as shown in Fig. 9.

The extreme upper rim of the skirt portion of the blank is engaged by the inclined shoulders c of the forming lugs 30 which impart an initial inward bend thereto as shown in Fig. 12 at all portions of the rim except those portions which are designed to form the inwardly extending lugs in the completed article. As shown at L in Fig. 12 the inward bending of the rim of the blank r B causes the portions of the rim designed to produce the lugs to be drawn slightly inwardly.

As soon as the outer confining and forming ring 29 engages the solid base or bed II] and the initial inward bend referred to above has been formed, the ring 29 yields and the heads of the guide bolts 3| (Fig. 2) are engaged by the flat washer 32 as the die holder l8 descends, carryin with it the remaining elements of the die assembly. The resilient sleeve 33 is thus compressed and serves to firmly hold the forming ring 29 on the bed or base I0.

As shown in Fig. 9, the extreme upper edge of the skirt portion of the blank B projects slightly inwardly of the inclined shoulder provided on the forming lugs 30 and thus continued descent of the die holder l8 and the inner forming ring G0 which moves therewith causes the inwardly projecting portions of the skirt to be engaged by the arcuate shoulders d of the forming tines 44 to fold these portions further inwardly from the position they assume in Fig. 9 to that shown in Fig. 10. During this secondary folding operation, the portions of the rim intended to produce the lugs are still further drawn inwardly as shown at L in Fig. 13 and are finally drawn to the position shown at L in Fig. 14 when the inner ring 43 reaches its lowermost position.

Immediately prior to movement of the inner forming ring ii) to its lowermost position, the arcuate groove (1 provided at the lower end of each forming finger 25 on the intermediate forming ring 23 and which occupies an elevation slightly higher than the elevation of the shoulder d as shown in dotted lines in Fig. 10, engages the partially formed and inwardly extending lug L and bends the same downwardly to the position shown at L in Figs. 15, 16 and 17, thus imparting final shape to the lugs and completing their formation.

It is to be noted that the formation of the inwardly folded rim of the skirt portion of the blank B and the formation of the lugs take place simultaneously through the stages of lug formation illustrated in Figs. 12, 13 and 14. Thus, throughout a major portion of the interval of time during which the lugs are in the process of being formed, no positive forming operation is conducted thereon and they are merely drawn inwardly following their own inclination as the edge of the skirt portion of the blank is folded. The final positive shaping operation which is performed by the forming fingers 26 is not of great magnitude and merely imparts a more desirable shape to the already formed lugs L and thus the operations, by means of which the lugs are formed, are conducive toward an inherent intercommumcating resiliency of the lugs by means of which they are smooth yet positive in their sealing action when the closure is applied to a container.

Modifications may be resorted to within the spirit and scope of the appended claims.

I claim:

1. An apparatus for forming metal closures from skirted blanks comprising a series of concentric dies including an outer die ring, an inner die ring and an intermediate die ring, means on the outer die ring for imparting an initial inward bend to spaced portions of the rim portion of a blank skirt and drawing the intervening 2. An apparatus for forming metal closures from skirted blanks comprising a series of concentric dies including an outer die ring, an inner die ring and an intermediate die ring, means on the outer-die ring for confining a blank on a press bed against lateral shifting, means on said outer die ring for imparting an initial inward bend to spaced portions of the rim portion of a blank skirt and drawingthe intervening portions thereof slightly inwardly of the blank, means on the inner die ring for folding the inwardly bent portions into substantial parallelism with the skirt body to further draw the intervening portions inwardly of the blank, means on the intermediate die ring for imparting final shape to said inwardly drawn intervening portions to produce a series of lugs, and mechanism for first moving the dies downwardly together and then moving the inner and intermediate dies downwardly as a unit beyond the outer die.

3. An apparatus for forming metal closures from skirted blanks comprising a series of con centric dies including an outer die ring, an inner die ring and an intermediate die ring, means on one of said rings for imparting an initial inward bend to spaced portions of the rim portion of a blank skirt to draw the intervening portions thereof slightly inwardly of the blank, means on another of said rings for folding the inwardly bent portions into substantial parallelism with the skirtbody to further draw the intervening portions inwardly of the blank, means on the other die ring for imparting final shape to said inwardly drawn intervening portions to produce a series of lugs, and mechanism for first moving the dies downwardly together and then moving the inner and intermediate dies downwardly as a unit beyond the outer die.

4. In apparatus for forming sheet metal closures, a pad for supporting a skirted blank in inverted position, mechanism for shaping the rim portion of the skirt and providing an internal hem and lugs therein consisting of three telescope die members positioned above the pad, the outer die member having its lower end shaped to bend circumferentially spaced portions of said rim inwardly a short distance and partially form lugs between said portions, the inner die member having its lower end shaped to fold said circumferentially spaced portions downwardly into spaced parallelism with the remainder of the skirt and drag the partially formed lugs inwardly, the intermediate die member having its lower end shaped to finally form the lugs and bend the free end portions thereof into parallelism with the remainder of the skirt, and mechanism for moving the dies downwardly together and then moving the inner and intermediate dies downwardly asa unit beyond the outer die.

CHARLES M. BELLG.

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