US2186519A - Manufacture of closures for containers - Google Patents

Description

J. BUONO MANUFACTURE OF CLOSURES FOR CONTAINERS Jam. 9, 1940.

Joke ab 3 00120 Filed Sept. 14, 1938 Patented Jan. 9,

murso'runs or cnosuans son I oon-rsmsns Joseph Buono, Brooklyn, N. Y.; assignor to Geo. V.

Clark 00., Inc., Long Island City, *poratlon of New York 4, weas l-m1 No. 229,966

Application September 1 6 Claims.

' This invention relates to manufacture of closures for containers; and itcomprises a method I of simultaneously making a closure and a clamping ring therefor wherein sheet material, such as sheet metal, for example, is punched-with at least one circle of cut-outs extending radiallyfrom a central point which eventually forms the I center of the cap of the closure, a circle is cut I around said central point including said out- 10 outs and an annularstrip of metal extending outside said circle of cut-outs thereby forming a closure blank, said annular strip eventually forming said clamping ring, said blank is then drawn into the form of a cap with a depending periph- 18 eral skirt, the lower edge of said skirt just below said cut-outs being expanded slightly and the marginal edge being curled, the expanded portion of said skirt then being cut oil! along a line coinciding with the lower edges of said cut-outs, 20 thereby separating the lower ring portion from the upper cap portion, the depending skirt of the cap portionbeing thereby formed into depending tongues, the lower ends of said tongues then being curled, if desired, the severed rin portion :5 being turned upside down, slipped over .the top of said cap portion and pressed downwardly over the said depending tongues, thereby forming a completed closure with clamping ring; several-of the steps, of said process being combined in one or more drawing or stamping operations, all as more fully hereinafter set forth and as claimed. This application is a continuatiomin-part of my copending application, Serial Number 138,257, filed on April 21,1937. My prior application describes and claims a closure with a clamping ring, as well as describing a process of making said closure and clamping ring from sheet metal. The present application is drawn to theIprocess described in the said prior application and in-e 0 eludes a somewhat more detailed description of the said process.

While several different methods can be devised for making the closures provided with clamping I rings, which are described in my prior acknowl- 5 edged application, I have found that one such method is particularly advantageous in that an important saving in material is obtained. I havealso found that this method enables several of the various procedural steps of the process to be so conducted at a single operating station and with a single die. In this new process the closure ring and the cap portion'of the closure are made from a single blank which is out from sheet material,

. such as sheet metal, compressed fibre, artificial 5 plastic or the like. A circle of cut-outs, radiating from the center of the blank is stamped in the metal either before or after the blank is cut out, the said cut-outs being separated from the periphery of the blank by an annular strip, the

metal of which strip eventually forms the clamp- 5 ing ring of the closure. The .blank with cutouts is then subjected to a drawing operation in which it isformed into cup or cap shape with a top and depending peripheral flange or skirt.

The top may be provided with a depressed central portion or panel in this same operation. The

depending skirt portion of the drawn blank includes the said annular strip as well as the cut outs. When the cut-outs are first punched out they are usually of triangular shape, the apex of the triangule being directed towards the center of the circle but during the drawing opera-v tion the outer portions of the triangles are forced together until the, triangular cut-outs become substantially narrow slits in the depending skirt of the drawn blank. The annular strip below the cut-outs, which eventually forms the clampingring, is expanded somewhat by the'die in the drawingoperation, the innner diameter of this ring portion corresponding substantially to the outer diameter of the upper cap portion of the blank. While the drawn blank remains in the I drawing die, the marginal edge of the ring portion of the blank is usually curled outwardly, a short straight-sided annular sectionbeing left 9 above the curl. In the next operation the lower ring portion of the formed blank is cut away from the upper cap portion along a line coinciding with the lower ends of the cut-outs. The clamping I I ring which isseparated in this manner is com- 35 plete and only requires being turned upside down before being applied to the closure cap. The portions of metal which lie between the cut-outsof the skirt of the remaining cap. are in the form of depending tongues after the cutting op- 40' eration and the ends of these tongues are advantageously curled in an operation which is usually performed in a separate die, this operation -I.cempleting the formation of the cap portion of the closure. The clamping ring is usually applied'over the cap and pressed downwardly over the depending tongues before the application of thefclosure to a container or before stacking. 1 The curl of the closure ring is separated from the I curl of the depending tongues by the straightsided section of the ring, this separation being suiiicient to provide for the insertion of a coin during removal of the closure fromthecontainer.

when a paneled top is used, it is desired to employ a rubber sealing element or,

gasket to produce an air-tight seal between the bead of the container and the cap. This can be accomplished by introducing a rubber sealing compound into the peripheral recess of the cap which fits over the head. This step can be conducted either before or after the clamping ring is applied to the cap of my closure.

My invention can be explained in more detail by reference to the accompanying drawing which shows, more or less diagrammatically, a series of die elements which can be used successively in performing the various steps of my process and in producing the closures and clamping rings which are described and claimed in my acknowledged copending application. In this showing:

Fig. 1 shows a perforating die in vertical section which can be used in making the cut-outs in the sheet metal, either before or after the blanks are separated from the sheet,

Fig. 2 is a vertical section of a blanking and drawing die in which the circular blanks may be cut, followed by the drawing operation in which the blanks are formed into cup shape, with an expanded lower ring portion below the cut-outs, This die is also capable of curling the marginal edges of the depending skirts of the drawn blanks,

Fig. 2a is a partial showing of the die of Fig. 2 on an enlarged scale, the die elements being in somewhat different position,

Fig. 2b is a partial section through the formed blank which is produced by the operation of the die shown in Figs. 2 and 2a,

Fig. 3 is a vertical section through a cutting die which serves to separate the clamping ring from the cap portion of the closure,

Fig. 3a is a similar partial view on an enlarged scale of the die shown in Fig. 3,

Fig. 3b is a partial section showing the clamping ring severed from the cap portion, as accomplished by the cutting die shown in Figs. 3 and 3a,

Fig. 4 is a vertical section through a die which serves to curl the ends of the tongues which depend from the cap of my closure, the die beirig in its open position, 1

Fig. 4a is a similar partial view on an enlarged scale showing the cap in the die at the concluclosed position, x;

Fig. 5 is a vertical section of the assembling die which presses the clamping ring downwardly over the cap of the'closure, the die being in its open position,

Fig. 5a is a partial showing of the same die on an enlarged scale with an assembled closure in the"die, the die being in its closed position,

Fig. 6 is a bottom view of the cutting tool or punch of the die shownin Fig. 1,

Fig. 7 is a plan view of the formed blank as it leaves the die shown in Figs. 2 and 2a,

Fig. 8 is an elevational view with parts in section showing a modified form of blank which can be produced by the operations of dies similar to those shown in Figs. 1 and 2,

Fig. 8a is an elevation, partly in section, of the closure cap whichis made from the blank of Fig. 8, while i Fig. 9-is a partial section of a modified closure ring within the present invention.

\ In the various figures, like elements are designated by like reference numerals. The sheet I of metal or the like is introduced at the left sion of the curling operation, the die being in its.

into the series of dies shown in Figs. 1 to 5. This seri of dies may be conveniently mounted on a the closure; see Figs. 2b and 8.

single rotary table or upon an elongated table, the metal sheet, the blanks and the formed parts of the closures being caused to move automatically and simultaneously step by step from one die to the next die following it in the series by means which form no part of the present invention and which are therefore not shown.

The die shown in Fig. 1 serves to punch out a circle of cut-outs, the cutting tool or punch 2 cooperating with the base 3. The teeth 4 of the cutting tool are shown best in Fig. 6 which is a bottom view of this tool. The teeth register with the openings 5 in the base of the die, through which the cuttings fall. The sheet of metal with cut-outs then passes directly to the forming die shown in Fig. 2.

The head or punch 6 of the die shown in Fig. 2

is provided with a circular cutting edge 1 which cooperates with a similar outing edge 8 on the base 9. These cutting edges serve to cut. out the blanks just before the forming or drawing operation which is performed in this die. The

- metal scrap is discarded by means not shown either before or after the drawing operation. The drawing of the blanks is accomplished by the central forming element or knock-out l0 and the punch 6 which cooperate with the central die element H of the base to form a cup shaped blank, the shape of this blank being evident from the shape of the parts shown in Figs. 2 and 2a. The knock-out is provided with an annular recess l2 which cooperates with the bead [3 of the base element to produce the paneled top Id of The skirt of the blank is made in two straight-sided portions, the lower section being off-set outwardly or expanded slightly at the shoulder 15, as shown in Figs. 2b and 8. This result is accomplished by means of the step I6 of the base element H cooperating with the cut away section or step ll of the punch 6.

During the drawing operation, which forms the depending skirt on the blank, the pressure ring I8 of the die is withdrawn to its lower posi- This curling operation is advantageously accomplished as the punch 6 is raised while the knockout serves to hold the top of the blank stationan. The proper timing of the various die elements to accomplish the desired operations as described can be readily accomplished within the skill of the art and by means not shown in the drawing. The shape of the finished blank, as formed in the die shown in Figs. 2 and 2a, is shown in partial section in Fig. 2b.

The next operation is the cutting of the lower ring from the cap portion of the blank. This operation can be accomplished, if desired, in the die shown in Figs. 2 and 2a. Thus, cutting can be accomplished between the shoulder or step 6 of the central element of the die and the step 22 of the punch 6, by lowering the punch until the twosteps pass each other. It is advantageous, however, to provide a special die to separate the clamping ring from the cap portion of the closure. Such a die is shown in Figs. 3 and 30.. I

The cup-shaped blank which is formed in the die of Fig. 2 is released from this die by tapping arcane the knock-out pin 23. The blank then drops upon a belt conveyor 24 which transports it to the die shown in Fig. 3. The knock-out 25 and the central base element 26 of this die are of the same shape as the corresponding elements of the die shown in Fig. 2. But the punch 21 of this die is provided with an inner circular cutting edge 28 which, when depressed sufficiently, passes the step 28a and serves to sever the clamping ring, shown generally at tll, from the cap portion of the closure along the shoulder l of the blank.

It will be noted that the triangular cut-outs formed by the die of Fig. 1 are compressed to form narrow slits 50 in the drawing operation performed by the die of Fig. 2. The lower edges of these cut-outs coincide with the-step ii of l the die of Fig. 2, as shown by the position of the shoulder l5 of the blank of Fig. 217. When this blank is severed at this shoulder II, it is 1 evident that the material between the slits is left in the form of a series of depending tongues 29. The lower ring portion of the blank then forms the clamping ring but the curl of this 'ring is upside down from its final position, as

shown in Fig. 4. The'clamping ring is released from the die by raising the pressurering 32 by means of the pressure pins 33. At this point in the procedure the conveyor belt 34 may be passed between the die elements shown in Fig. 3. This belt maybe provided with circular cut-outs with clips on each side to receive and hold the rings 60 whfle they are being reversed in position and conveyed around the station shown in Fig. '4, finally being brought to the assembling die shown in Fig. 5.

At the station shown in Fig. 4, the depending es 29 of the cap portion of the closure are curled at their ends. In this die the ring 33 is provided with the curling groove 38 and, when the die is closed, the ends of the depending tongues 29 of the cap portion of the closure are forced into this groove and the curl 31 is thereby formed as shown in Fig. 4a. The finished cap is released from the die of Fig. 4 either by tapping the knock-out pin 33 or by raising the pressure base 39 by means of the pressure pins 40. The cap is then transported by means of conveyor belt 4| to the assembling die shown in Fig. 5a the two elements are shown in assembled position, the clamping ring being forced down over the cap until its depending skirt strikes the curled tongues of the cap. In this position the closures can be applied to the containers in a manner understood in the art. J I

The assembled closures are released from the die shown in Fig. 5 by tapping the knock-out pin'42. They can be conveyed by the belt from this-station to another station, not shown, at which a rubber compound is applied in the recess 43 of the cap to serve as a sealing element or gasket. If no rubber, compound is to be employed, the belt 44 can be used to transport the closuresto a stacking station, to an electro- Fig. 8 there is shown a rough blank as it leaves the die shown in Figs. 2 and 20., this blank being identical to that shown in Fig. 2b with the exception that the slits 50a are not extended down to the shoulder Ii of the blank. It is obvious that this modified blank can-be formed with dies which'are identical to those shown in Figs; 1, 2 and 2a, with the exception that the cutting teeth 4 of the die of Fig. 1 are displaced inwardly, that is the punch 2 is slightly smaller in outside diameter. When this blank is passed through the cutting die of Figs.'3 and 3a, which severs the cap from the ring at the shoulder IE it is evident that no tongues are formed on'the cap portion of the severed blank since the slits We are some distance above the shoulder l5, that is, the peripheral edge of the cap portion is continuous. This peripheral edge is then curled in the die of Figs. 4 and 4a in order to form the continuous curl 3111., as shown in Fig. 8a.

Several advantages are gained by this modified construction. The continuous curl 31a is somewhat stronger than the curled tongues 3'! of the modification described previously and all rough edges on these curled tongues, which might be caused by slightly worn dies, are eliminated. In the modification described previously the. peripheral .edge of the depending. skirt 5| of the closure ring is likely to have indentations coinciding with the slits 50 unless the cutting edge' of the die of Figs. 3 and 3a coincides exactly with the, lower ends of the slits 50. In the modification shown in Figs. 8 and 8a, however, this difficulty is eliminated since the blank is severed some distance below the slits. i

In Fig. 9 I have shown a slightly modified closure ring in which the lower edge of the skirt 5| is bent back upon itself to form a fold 52. This serves to strengthen the ring. Another advantage is that the lower edge 53, of the ring is rounded and free from all sharp edges. The fold 52 may be made of variable length. The details of the construction of the dies adapted to produce the required folding operation, resulting in the fold 52 of the closure ring shown in Fig. 9, are, of course, obvious to those skilled in this art. It is not believed to be necessary, therefore, that these dies be illustrated in the drawing.

The operations which have been described as taking place at the various stations represented in Figs. 1 to 5 are advantageously conducted automatically, step by step and on a single table upon which the various dies are-positioned. Suitable methods for obtaining proper timing of I the die elements, coordination of the various operations and conveyance of the parts from one .station to the following stations are well known in the art. Since a complete description of the various means required to accomplish this result would needlessly burden the present description and since these means form no part of the present invention, such description is omitted, in this application.

- While I have described what I consider to be the best embodiments of my invention, it is obvious, of course, that various modifications can be made in the various operations and in the various dies which have been described, without departing from the purview of the, present invention. For example, it is evident that the cut-outs which are made of triangular or V-shape in the operations which have been described, can be made of U-shape with the production of substantially the same results. The operations shown by the various dies can be performed vertically, horizontally or at another angle.' Either or both of the curling operations can be omitted. It is also possible to eliminate the periorating step in which the cut-outs are formed, the cap in this case being formed without the depending tongues. Other modifications which fall within the scope of the following claims will be immediately evident to those skilled in this art.

What I claim is:

1. In the manufacture of closures with clamping rings, the process which comprises cutting a circular blank from sheet metal, drawing said blank into the form of a cap with 2. depending peripheral skirt, the lower ring portion of said skirt being expanded slightly during the drawing operation to such an extent that its inner' di ameter substantially corresponds to the outer diameter of the upper cap portion of the skirt, curling the margin of said ring portion of the skirt leaving a short straight-sided section above said curl, severing said ring portion of the skirt from the cap portion, curling the marginal edge of the skirt of the cap portion, turning the severed ring portion upside down and applying it over the cap portionas a clamping ring.

2. In the manufacture of closures with clamping rings, the process which comprises perforating a sheet of metal with a circle of cut-outs of substantially triangular shape with the apex of the triangles pointing to the center of said circle, cutting a circular blank concentrically with said circle of cut-outs including an annular strip of metal outside said cut-outs, drawing the resulting blank into the form of a cap with a depending peripheral skirt, the lower ring portion of said skirt just below said cut-outs being expanded I slightly during the drawing operation, curling the marginal edge of said ring portion outwardly, leaving a narrow straight-sided strip above the curl, severing the ring portion of said skirt from the u per cap portion on a line substantially coinciding with the lower ends of said cut-outs, curling the ends of the resulting depending tongues between said cut-outs, turning the severed ring portion upside down and applying it over the cap portion as a clamping ring, the curl of said ring being separated from the curled tongues by said straight-sided strip, said strip having "a width suiiicient to provide for the insertion of a coin between said curls.

3. In the manufacture of closures with clamping rings, the process which comprises perforating a sheet of metal with a circle of cut-outs of substantially triangular shape with the apex of the triangles pointing to the center 01 said circle, cutting a circular blank concentrically with said circle of cut-outs including an annular strip of metal outside said cut-outs, drawing the resulting blank into the form of a cap with a depending peripheral skirt, the lower ring portion 0! said skirt below said cut-outs being expanded slightly during the drawing operation, curling the marginal edge of said ring portion outwardly, leaving a narrow straight-sided strip above the curl, severing the ring portion of said skirt from the upper cap portion along a line slightly below the lower ends of said cut-outs, curling the continuous peripheral margin of the depending skirt of the resulting severed cap portion, turning the severed ring portion upside down and applying it over the cap portion as a clamping ring, the curl of said ring being separated from the curl of said cap portion by said straight-sided strip, said strip having a width sumcient to provide for the insertion of a coin between said' curls.

4. In the manufacture of closures with clamping rings, the process which comprises cutting'a circular blank from a sheet of material, drawing the resulting blank into the form of a cap with a top and a depending peripheral skirt, the said skirt being formed with two substantially straight-sided sections the lower of said straightsided sections having a diameter slightly larger than the upper of said sections, curling the lower 5. The process of claim 4 wherein, prior to the drawing operation, a circle of cut-outs is punched in the said sheet of material, said circle of cutouts being positioned concentrically in the circular blank and being so placed that the peripheral ends of said cut-outs will substantially coincide with the junction point between said upper straight-sided section and said lower straightsided section of the peripheral skirt after the drawing operation.

6. The process of claim 4 wherein, prior to the drawing operation, a circle of cut-outs is punched in the said sheet of material, said circle of cutouts being positioned concentrically in the circular blank and being so placed that the peripheral ends of said cut-outs will lie slightly above the junction point between said upper straightsided section and said lower straight-sided section 01' the peripheral skirt after the drawing operation. v

JOSEPH BUONO.

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