US3245371A

US3245371A - Method and apparatus for making a tear strip metal container

Info

Publication number: US3245371A
Application number: US321169A
Authority: US
Inventors: Eckman George Ernest
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1963-11-04
Filing date: 1963-11-04
Publication date: 1966-04-12
Anticipated expiration: 1983-04-12

Description

April 12, 1966 e. E- ECKMAN 3,2

METHOD AND APPARATUS FOR MAKING A TEAR, STRIP METAL CONTAINER Filed Nov. 4, 1963 6 Sheets-Sheet 1 FIG. I N

OOODOOOOOODOOOQOOOQDOQDUQGOOO0 INVENTOR. Maw:- fiP/vgr [aw/4y g; a QM;

v ATTORNEY G. E. ECKMAN 3,245,371 METHOD AND APPARATUS FOR MAKING A TEAR STRIP METAL CONTAINER I April 12, 1966' e Sheet s-Sheet 2 Filed Nov. 4, 1963 R O Q m m NM 1 R Q sq s i E m we .WNN \m v www i 1 .l N uv 4 Jwww Q 5% W% H-\ Q. m W L M J M Q Y ssh ww m v, w 11 \7 awn m/va MmA/v ATTORNEY April 12, 1966 "G. E. EKMA- -3 ,245 ,371

M ETHODAND APPARATUS FOR MAKING A TE AR STRIP METAL CONTAINER Filed Nov. 4, 1963 6" Sheets-Sheet 5 FIG. 7 4 144 A W IE I IN VEN TOR. 650 965 f/FAM'JTfZXMJ/V *ATTOYRNEYY April 12, 1966 Filed Nov. 4, 1963 FIG. l0

G- E. ECKMAN METHOD AND APPARATUS FOR MAKING A TEAR STRIP METAL CONTAINER 6 Sheets-Sheet 4 &

- INVENTOR. 647/962 f/P/VZJTZKK/V/AN ATTORNEY April 12, 1966 G. E. E(IZKMAN I 3,245,371

METHOD AND APPARATUS FOR MAKING A TEAR STRIP METAL CONTAINER Filed Nov. 4, 1963 6 Sheets-Sheet 6 FIG. I? FIG. I9

a Fl 6J8 V q gp FIG. 20 210 l 131 g); 202 M INVENTOR. 'ffl/P6f [FA/[ 7' [ilk/ 14 BY g QM ATTORNEY United States Patent 3,245,371 METHGD AND APPARATUS FGR MAKING A TEAR STRIP METAL CONTAINER George Ernest Eckman, Oradell, N.J., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Nov. 4, 1963, Ser. No. 321,169 Claims. (Cl. 113-11) The present invention relates to a method and apparatus for making a metal container having a tear strip opening feature, and more particularly to such a method and apparatus wherein the container bodies are pre-notched, scored to form a tear strip therein, and then headed and folded adjacent the tear strip prior to the body-forming and side seaming operations to provide shielding for the raw metal edge which is formed on the container body after the removal of the tear strip therefrom by the consumer.

Examples of the type of metal container to be produced by the instant apparatus and method are disclosed in United States Letters Patent to Pillnik, 3,055,539, issued September 25, 1962. Such a container is provided with a continuous folded bead extending inwardly or outwardly of the container body and having a rounded or curved upper edge disposed adjacent to the lower of a pair of score lines defining a tear strip in the container body. When the container is opened by removal of the tear strip by the consumer, the raw edge produced by the lower score line is substantially shielded by the adjacent rounded upper edge of the folded bead.

The general purpose of this invention is to provide a method and apparatus capable of producing a bead or fold in a container body of the type covered by this Pillnik patent, or of a generally similar type. To accomplish this purpose, the present invention contemplates a novel method and apparatus for producing a fold in a container body wherein the flat can body blank is pre-notched and pre-scored and thereafter, prior to the body-forming and side seaming operations, the container body blank is beaded and folded in the fiat by several pairs of cooperating rollers.

The present method and apparatus may be utilized with can body blanks of any size; provide consistently accurate placement of the protecting fold with respect to the lower score line; eliminate any possibility of damage to the side seam of the container body since the beading and collapsing operations take place prior to the side seaming operation; and are adaptable to the rapid manufacture of large numbers of folded container bodies.

It will be reailzed that the principles of the instant invention are not limited to the production of can bodies of the type disclosed by the aforementioned Pillnik patent, but can be applied to the production of many types of bodies which embody a folded wall portion, such as, for example, folded can bodies of the type shown in United States Letters Patent 1,615,930.

An object of the present invention is the provision of a novel apparatus and method for producing a protecting head or other fold in a container body blank.

Another object is to provide such a method and apparatus which may be utilized with container bodies of any size and which accurately locates the fold on the container body.

A further object is the provision of method and apparatus for producing a fold or collapsed bead in a predetermined position on a pre-scored, fiat, container body blank.

A still further object is to provide such a method and apparatus wherein the pre-scored portion of the container body blank is protected against possible damage during Patented Apr. 12, 1966 the beading and collapsing or folding operations on the blank.

Yet another object of this invention is the provision of an apparatus which is capable of producing folds in a plurality of fiat container body blanks in a rapid and efiicient manner.

Yet another object is the provision of a method of forming a folded tearing strip can body wherein the projecting tearing tongue is formed after the body folding operation in order to minimize the possibility of its being damaged during manufacture of the can body.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

FIG. 1 illustrates a plan view of an apparatus constructed according to the principles of the instant invention;

FIG. 2. is a front elevational view of the apparatus shown in FIG. 1; I

FIG. 3 is an enlarged sectional view taken substantially along line 33 in FIGURE 1;

FIG. 4 is a plan view of a portion of the apparatus shown in FIG. 3;

FIGS. 5 through 9 are elevational views, with parts broken away, of the can body blank during various method steps of the instant invention;

FIG. 10 is a perspective view of a folded can body after the blank has been formed into tubular shape and the edges thereof disposed in a lock and lap side seam;

FIGS. 11 through 16 are enlarged, fragmentary, elevational views in section, showing the relationship of the can body blank and the forming rolls of the instant apparatus during the various steps involved in forming a protecting fold in the blank according to the instant method;

FIG. 17 is an enlarged elevational view, with parts broken away, of the side seam portion of the container body with the side seam edges interlocked but prior to the bumping operation;

FIG. 18 is an enlarged sectional View taken subsantially along line 18-18 in FIG. 17;

FIG. 19 is an elevational view similar to FIG. 17, showing the can body side seam after it has been subjected to a bumping operation; and

FIG. 20 is an enlarged sectional view taken substantially along line 20-20 of FIG. 19, showing in broken lines, the bumping hammer and spline utilized in the bumping operation.

As a preferred or exemplary embodiment of the instant invention, FIGS. 1 and 2 illustrate the apparatus for prenotching, scoring and forming a protective, folded bead in a metal can body blank which is ultimately to be formed into a can body of the type covered by the aforementioned Pillnik patent. Rectangular can body blanks A of a predetermined size are first fed by any suitable means (not shown) to a preliminary notching station 22 comprising a platform 24 which is mounted on a frame 26.

. The platform 24 is provided with a pair of parallel, raised side guides 27 which are spaced a distance approximately equal to the Width of a can body A so as to form a channel 29 between them in which the can bodies A are slidably disposed. The can bodies A are intermittently advanced j along the channel 29 in a conventional manner, as by reciprocating feed bars 28 which are slidably disposed on the platform 24 and are provided with spring-biased feed dogs 30 which engage the rear of the can body blanks A and advance them in the channel 29 during the forward stroke of the feed bars 28, in a manner sub- 3 stantially the same as that disclosed in the patent to Peters, 1,770,041.

As shown in FIG. 2, the feed bars 28 are reciprocally driven by a motor 32 connected to a gear box 34 of suitable construction which in turn rotates a face cam 36 that effects reciprocation of the feed bars 28 via a suitable oscillating lever 37 which is provided with a cam roller 38 which operates in the groove of the cam 36. A shaft 40 from the gear box 34 is connected in a suitable manner (not shown) to a notching tool or member 42 which is slidably mounted for reciprocal movement on vertical posts 44. The vertical reciprocation of the notching tool 42 is in conjunction with the horizontal reciprocation of the feed bars 28 such that a blank A is positioned and maintained stationary under the notching tool 42 on its downward stroke so that laterally aligned

notches

46, 47 are cut in the sides of the blank A as shown in FIG. 6. Thereafter, on the upward stroke of the notching tool 42, the notched blank A is removed from under the notching tool 42 and, prior to or during the succeeding downward stroke of the notching tool, an unnotched blank A is advanced by the feed bars 28 into position under the notching tool 42. It will be understood that the

notches

46, 47 are formed prior to the bead forming operation because these notches will be incorporated in the finished bead.

A pair of support bars 48, 49 (FIG. 1) are disposed in perpendicular relation to the feed bars 28, and are mounted on the frame 26 at a slightly lower elevation than and at the end of the platform 24. A raised stop or gauge bar 50 is mounted on the support bar 49 in such manner that a pre-notched blank A advancing along the platform 24 falls onto the support bars 48, 49 and is stopped by the gauge bar 50. The pre-not'ched blank A is advanced along the support bars 48, 49 (to the left as seen in FIG. 1) by feed dogs 52 mounted on an endless chain conveyor 54 which is disposed between the support bars, 48, 49. The feed dogs 52 extend above the level of the bars 48, 49 to thereby engage the rear edge of each pre-notched blank A. The chain 54 is mounted on an idler sprocket 55 and a driving sprocket 56 which is driven in a manner to be described hereinafter.

A pair of

skew rollers

58 and 59 are mounted on the gauge bar 50 to engage the upper surface of each notched blank A as it is moved along the support bars 48, 49. The

skew rollers

58 and 59 are angularly disposed relative to the gauge bar 50 for the purpose of crowding or urging the blanks A against the gauge bar 50 to maintain the blanks A in a gauged position against the gauge bar 50 as they are advanced along the support bars 48 and 49 by the chain conveyor 54.

As the pre-notched and gauged blank A approaches the ends of the support bars 48 and 49, one edge of the blank (the one at the top as seen in FIG. 1) is engaged by a first series of longitudinally aligned gauging rollers 60 fixedly mounted for rotation on a longitudinally extending, U-shaped bracket 61. The opposite edge of the blank A is simultaneously engaged by a second series of gauging rollers 62 which are adjustably mounted on a second U-shaped, longitudinally extending bracket 63. The brackets 61 and 63 are supported on a plurality of vertical support members 64 mounted on a frame 66 which is disposed at right angles to the frame 26 (see FIGS. 1 and 2).

As shown in FIGS. 3 and 4, each of the adjustable gauging rollers 62 is adjustably mounted on an eccentric portion of a threaded shaft 68 which may be locked in a predetermined position by a nut 70 on the upper end thereof. The successive gauging rollers 62 are adjusted so as to be progressively closer to the gauging rollers 60 for a reason which will be apparent from the description hereinafter.

As the blank A passes between the series of gauging

rollers

60 and 62, it is successively engaged by six pairs of cooperating rolls 72 through 77 which perform predetermined operations on the blank A, to be described in detail hereinafter. The second pair of rolls 73 and their operating mechanisms, which are exemplary of the others and are the only ones shown in complete detail (see FIG. 3), comprise an upper roll 78 and a lower roll 79 which are rigidly mounted on

counter-rotating shafts

80 and 81, respectively, that are in turn rotatably mounted in a supporting frame 82. A gear 83 is rigidly mounted on the shaft 80 and is in engagement with an identical gear 84 on the shaft 81, with the result that shafts 80 and 81 (and the

rolls

78 and 79 thereon) rotate in opposite directions at the same peripheral speed. A pair of sprockets 86 and 87 are rigidly mounted on the end of the shaft 81 adjacent the gear 84 so as to be rotatable with the shaft 81. A driving motor 88 (see FIG. 2) is connected to the sprockets 86 and 87 and to similar sprockets on the shafts of the other pairs of cooperating

rolls

72 and 74 through 77 by a series of endless drive chains 89 through 94, as shown in FIG. 1.

Each of the pairs of

rolls

72 and 74 through 77 is mounted on shafts similar to the

shafts

80, 81 and is provided with a pair of cooperating identical gears which are of the same size as the gears 83 and 84 so that all of the pairs of rolls 72 through 77 rotate at the same peripheral speed, which speed is preferably slightly greater than the lineal speed of the chain conveyor 54 so that once the blank A is gripped by the rolls 72, it is pulled out of contact with the feed dog 52 and its advancement thereafter is effected by the paired rolls 72 through 77. Thus, it is desirable that the spacing between the paired rolls be less than the length of the blank being operated upon so that the blank is always in the grip of at least two of the pairs of rolls to thereby effect positive transfer.

A shaft drive chain 96 (see FIG. 1) operatively connects the lower shaft of the roll pair 72 to a cross-shaft 98 which is rotatably mounted in suitable bearings and carries the driving sprocket 56 for the endless chain couveyor 54. The conveyor 54, therefore, is also driven by the motor 88 which drives the drive chains 89 through 96.

In accordance with the method of the instant invention, the pre-notched blanks A are first advanced between the first pair of counter-rotating rolls 72 (see FIG. 11) comprising an upper scoring roll 100 having a pair of continuous, circumferential scoring projections 101. The lower roll 102 of the pair 72 has a smooth continuous peripheral surface which supports each blank A as it is "being scored by the projections 101 of the scoring roll 100. As shown in FIGS. 7 and 11, the first pair of rolls 72 forms a pair of

parallel score lines

104 and 105 extending from one side to the other of the blank A, the score line 104 being disposed above the notches 46, 47 (see FIG. 7) and the score line 105 being disposed between the

notches

46, 47. The score lines 104, 105, therefore, define a tear strip 107 therebetween which includes a portion of each of the

notches

46, 47.

The notched and scored blanks A then advance between the counter-rotating rolls 78 and 79 of pair 73 (FIGS. 3 and 12). The upper roll 78 is bolted to a mounting flange 109 formed integral with the shaft 80 and is formed in one piece and is provided with an annular recess 106. The lower roll '79 comprises a first or forming ring 108 having a peripheral forming projection 110, the roll 79 being bolted to a mounting flange 112 which is integral with the lower shaft 81. The lower roll 79 further comprises a second ring 118 having a radially extending end flange 120, this ring 118 also being bolted to the mounting flange 112. Between the end flange 120 and the forming ring 108 there is disposed a third or clamping ring 122 having an outside diameter slightly greater than that of the forming ring 108. A cushioning ring 124 of a flexible and resilient material, such as rubber or a synthetic equivalent thereof, is interposed between the hub of the second ring 118 and the clamping ring 122.

As each blank A passes between the bite of the

rolls

78 and 79, the scored or upper portion of the blank A is firmly gripped between a portion 128' of the upper roller 78 and the clamping ring 122 of the lower roller 79, the rubber cushioning ring 124 compressing slightly to insure a constant clamping pressure. The forming projection 110 on the forming ring 108 engages a portion of the blank A relatively close to the lower score line 105 and forces it into the annular recess 106 in the upper roll 78 to form a continuous shallow longitudinal bead 130 in the blank A, as shown in FIG. 12. The head 130 inblank A comprises a curved portion 132 adjacent one side of the annular recess 106 and a relatively straight, sloping portion 134 extending from the curved portion 132 to the other side of the annular recess 106. The roller 78 is provided with rounded corners 136 and 137 adjacent the recess 106 so that the shallow bead 130 in blank A gradually merges with the adjacent flat or straight portions of blank A.

It is noted that the peripheral portion 138 of the forming ring 108 adjacent the forming projection 110 is spaced from the upper roll 78 a distance which is greater than the thickness of the blank A. Thus, since the scored portion of blank A is gripped between the upper and lower rolls 78. and 79, the additional metal required in the forming of the shallow bead 130* is provided by pulling the unscored and unclamped lower portion of blank A (the portion to the left of the bead 130 as seen in FIG. 12) inwardly toward the forming projection 110. As shown in FIG. 12, the eccentrically mounted gauging rollers 62- are maintained in contact with the shortened blank A, since they are adjusted inwardly toward-s the fixedly mounted gauging rollers 60 a predetermined amount to compensate for the decreased width of the blank A. During the forming of the shallow bead 130 in each of the blanks A, the

score lines

104 and 105 are protected against damage, since the scored portion of blank A is gripped between the clamping ring 122 and the portion 128 of the upper roll 78, across a pressure area which includes the score lines 104, 105 as well as extending some distance beyond them. Substantially uniform pressure is exerted across this area because the compression of the rubber ring 124 compensates for slight variations in the thickness of the blanks A. As a result of this uniform clamping pressure to the right of the projection 110 (as seen in FIG. 12), and the complete absence of clamping pressure to the left of the bead 110, there is no tendency to pull any of the metal in the blank A from the portion adjacent the score lines 104, 105 and the possibility of tearing the blank along these weakened lines is eliminated. The cushioning ring 124 adjacent the clamping ring 122 also serves to dampen any vertical forces on the scored portion of blank A, thereby further insuring against the possibility ofv damage to the

score lines

104 and 105 during the bead forming operation.

The mounting and construction of the third, fourth and fifth pairs of forming

rolls

74, 75 and 7.6, respectively, is substantially the same as that of the second pair of forming rolls 73, which is illustrated in detail in FIG. 3, except for the differences in construction and operation to be described hereinafter.

FIG. 13 discloses a blank A when it is passing between the third pair of forming rolls 74. This pair 74 comprises an upper roll 140 having an annular recess 142 which is substantially similar in shape to but somewhat deeper than the recess 106 in the roll 78 of the pair 73. The forming ring 144 has a recessed peripheral portion 145 and a peripheral forming projection 146 adjacent thereto. The forming projection 146 has a smaller radius of curvature than that of the forming projection. 110 on the forming ring 108, and the forming projection 146 extends radially outwardly from the forming ring 144 a greater distance than the forming projection 110. Thus, the forming projection 146 reforms the bead 130in. blank A so that; the curved portion 132 has a smaller radius of curvature and extends outwardly of the flat portion of blank A a greater distance than that provided by the second pair of forming rolls 73. In this pair of rolls 74, as in the

other pairs

73 and 75 to 77, the clamping ring 122 is backed-up by a rubber cushioning ring 124, so that the vulnerable scored area which contains the score lines 104, 1-05 is uniformly clamped and held secure against any transverse movement which would otherwise be induced by the bead forming operations efiected by these sets of rolls. In addition to this, the clamping action also insures that the adjacent edge of the blank A is held in contact with the first set of gauging rollers 60, thus insuring lateral gauging of the blank A as it passes through the pairs of rolls. This gauging is insured by the second series of gauging rollers 62 which positively prevent the blank A from being moved away from the gauging rollers 60. It will be realized, however, that the rollers 62 are to some extent precautionary, since there is very little chance for lateral movement of the blank A once it is clamped by the pairs of rolls 72 through 77.

The fourth pair of forming rolls (see FIG. 14) comprises an upper roll having an annular, V-shaped recess 152 with a sloping wall 154 and a vertical wall 156 merging in a sharply curved corner 158. The forming ring 160' of lower roll 161 is provided with a recessed peripheral portion 162 and a forming projection 163 adjacent thereto. The forming projection 163 comprises a sloping straight wall 164 and a vertical wall 166 which are substantially parallel to the sloping Wall 154 and the vertical wall 156, respectively, defining the V- shaped recess 152 in the upper roll 150. The sloping wall 164 and vertical wall 166 of the forming projection 163 merge in a curved corner 168 having a radius of curvature which is substantially smaller than that of the forming projection 146 on the forming ring 144 (FIG. 13). The continuous bead 130 in each blank A, therefore, is reshaped by the forming projection 163 and is provided with a longer sloping portion 134, a more sharply curved portion 132, and a vertical wall 170 be tween the curved portion 132 and the scored, flat portion of the blank A. As shown in FIG. 14, the adjustable gauging rollers 62 adjacent the fourth pair of forming [r0118 75 are located inwardly a greater distance than the preceding rollers 62 to compensate for the further decreased Width of blank A.

The fifth pair of forming rolls 76 (see FIG. 15) comprises an upper roll 172 having an annular V-shaped recess 174 of substantially the same shape as that of the V'- shaped recess 152 in forming roll 150. (FIG. 14) but of a somewhat greater depth. The forming ring 176 has a recessed peripheral portion 177 and a forming projection 178 adjacent thereto which is similar to buthigher than the forming projection 163, having a corner 180 which extends further into its respective upper roll trecess 174 than does the corner 168, the corner 180 having a smaller radius. of curvature than the corner 168. The continuous bead 130 of each blank A is thus further reformed by. the pair of forming rolls 76, the curved portion 132 being provided with an even smaller radius of curvature, the vertical wall 170 being increased in length and the angle of inclination of the sloping wall 134 also being increased.

It is noted again that the peripheral recessed portions of the forming rings of the pairs of forming rolls 73 through 76 serve to allow the unscored or lower portion of each of the blanks A to be pulled transversely into the bead 130, thus shortening the unscored portion of the blanks A. The eccentrically mounted gauging rollers 62 are adjusted to compensate for this gradual decrease in width of each blank A. During each of these operations on the blanks A, the scored portion of each blank is gripped between the upper roll and the rubber backed clamping ring 122 of the lower roll, and is thus protected against damage.

FIG. 16 illustrates a blank A when it is positioned between the sixth and final pair of formingrolls 77. The

pair 77 comprises an upper roll 182 having a shallow annular recess 184 with a sloping straight wall 186 and a short vertical wall 188 merging in a gradually curved portion 190. The lower roll 192 is of one-piece construction and is formed with a continuous fiat surface 194. The

rolls

182 and 192 serve to collapse or fold the vertical wall 170 of the bead 130 in blank A such that the bead 130 is reformed into a triple-thickness protective fold 131, wherein the rounded edge of the curved portion 132 is in transverse alignment with or in substantially the same transverse plane as the center of the score line 104 adjacent thereto, as shown in FIGS. 8 and 16.

In order to effect this collapsing operation, the recess 184 is disposed nearer to the scored portion of the blank A than are the grooves 106, 14-2, 154 and 174, all of which are substantially aligned with each other. In addition, the angle of inclination of the sloping recess wall 86 is substantially less than the angle of inclination of the sloping blank wall 134 produced by the preceding roll set 76. This insures the proper laying down of the wall 134 and the consequent accurate folding of the vertical wall 170 to produce the triple fold 131.

It will be noted that the rubber cushioned clamping ring 122 is not utilized at this final collapsing station. The reason for this is that this ring 122 is not necessary, since the offsetting of the recess 186 eliminates any tendency to pull or stretch the metal in the scored area of the blank. It will also be noted that the bottom roll 192 is not recessed, as are the other bottom rolls 108, 144, 160 and 176. The reason for this is to provide a support under the blank A on both sides of the folded bead 131 to insure that all portions of the blank A are disposed in a single plane.

As each of the blanks A leaves the sixth pair of forming rolls 77, it is deposited in a receptacle 1% which is mounted on the main frame 66 and wherein the prenotched, scored, beaded and folded body blanks A are vertically stacked. It is to be understood, of course, that the body blanks A need not be vertically stacked after they have passed through the forming rolls 72 through 77. Instead, the banks A may be stacked in some other manner or may be transferred directly to another conveyor or transferred to other types of forming apparatus.

From the receptacle 196, the folded blanks A are transferred in any suitable manner to a final notching station (not shown) wherein each blank is finally notched and provided with slits 197, as shown in FIG. 9, to form the tearing tongue 198 integral with the tear strip 107 and the lock sections 200 and

lap sections

202, 204 in blank A. This final notching and slitting operation can be ef- 'fected in a conventional notching and slitting mechanism, such as that disclosed in United States Letters Patent 1,770,041, merely by the substitution of properly configured dies, and thus it is not necessary to illustrate this mechanism.

The folded, slit and finally notched body blank A of FIG. 9 is then transferred by any suitable means to a cam body making apparatus (not shown) wherein the blank A is formed into a cam body B, with the sides of the blank A being disposed in a conventional lock and lap side seam wherein the lock sections 200 are reversely bent to form interlocking hooks as shown in FIGS. 10, 17 and 18. In order to avoid unnecessary thickness of the can body B where the fold 131 crosses the side seam area, only two of the three thicknesses of the folded bead 131 are disposed in overlapping relation at the lap portion of the side seam (see FIG. 18), with the result that at the upper lap section of the side seam there is a maximum of four thicknesses of the body blank A. This is accomplished because of the

notches

46 and 47 formed in the blank A which provide short double-thickness folds 205 at each side of the blank A which merge with the triplethickness fold 131.

The can body side seam is then subjected to a bumping operation (FIGS. 19 and 20) wherein the side seam is compacted by being compressed between a stationary spline 206 acting as an anvil and a movable hammer elernent 208 which is moved with an impact blow from a descended position to the ascended position shown in broken lines in FIG. 20. The spline 206 is provided with a recess 210 adjacent the upper lap section of the side seam, so that the bumping hammer 208 presses the overlapped double-thickness portions 205 of the folded bead in the lap section into the recess 210, thereby providing a relatively smooth and continuous outer surface S at the side seam of the can body B. The side seam of the can body B is then soldered in the conventional manner (not shown) and, since the side seam has a relatively smooth outer surface S, the solder flows freely along the side seam to provide a hermetic bond at the side seam.

A can body B is thus produced having a tearing strip opening feature with an integral tearing tongue, a hermetically sealed side seam, and a protective, continuous folded bead which is in transverse alignment with the lower score line, thereby shielding the raw edge which is produced at the lower score line when the tear strip is later removed from the completed container by the consumer. It is apparent that the instant apparatus and method may be utilized for the forming of such a protective folded head on the interior rather than the exterior of a container body, and also that the instant apparatus and method could be utilized for producing various shapes of folded body beads to be used for the same or various other purposes.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. Apparatus for forming a folded bead adjacent a tear strip in a fiat metal container body blank, said tear strip being defined by a pair of parallel score lines which are perpendicular to the sides of said blanks, comprising at least one pair of closely adjacent counter-rotating forming rolls between which said body blank is advanced, one of said rolls having an annular recess and the other of said rolls having a peripheral forming projection which extends into said recess and forces the adjacent portion of said advancing blank into said recess to form said shallow bead in said blank, said bead being parallel and adjacent to one of said score lines, at least one pair of closely adjacent counter-rotating reforming rolls adjacent to and in alignment with said pair of form ing rolls so that said blank is advanced therebetween, one of said reforming rolls having an annular reforming recess and the other of said reforming rolls having a peripheral reforming projection with a sharply curved corner which extends into said reforming recess to press said shallow bead into said reforming recess and to reform it into said relatively deep bead having a sharply curved corner, and means mounted adjacent to said reforming rolls for collapsing the reformed head into a triple thickness fold with the rounded edge of said sharply curved corner disposed closely adjacent to and in transverse alignment with said one score line.

2. The apparatus as defined in claim 1 with means to cut a pair of laterally aligned notches in the opposite sides of said blank in such a position that said one score line and said head are subsequently formed therebetween.

3. The apparatus of claim 1 wherein said head collapsing means comprises a pair of closely adjacent counterrotating rolls in alignment with said pairs of forming and reforming rolls so that said blank is advanced therebetween, one of said collapsing rolls having a shallow annulat collapsing recess and the other of said collapsing rolls having a continuous outer surface so that said relatively deep bead is collapsed into said collapsing recess to form said triple-thickness fold.

4. The apparatus of claim 1 wherein said pair of forming rolls and said pair of reforming rolls grip the scored portion of the blank as it passes between each pair to thereby protect said score lines from possible damage during the forming and reforming of said shallow bead in 3 said blank.

5. The apparatus of claim 4 wherein said other roll of both said pair of forming rolls and said pair of reforming rolls is provided with a peripheral recessed portion adjacent to and out of contact with the unscored portion of said blank on the opposite side of said bead from said scored portion, whereby the additional metal needed for the formation and reformation of said bead is drawn from said unscored blank portion.

6. Apparatus for forming a tear strip and a folded protecting bead adjacent thereto in a fiat metal can body blank comprising means for forming in said blank a pair of parallel score lines which are perpendicular to the sides of said blank and which define a tearing strip therebetween, successive pairs of closely adjacent counterrotating forming rolls mounted in alignment with said scoring means to receive the scored blank therefrom, said forming rolls pressing in said blank a continuous bead having a rounded edge which is parallel and adjacent to one of said score lines, and a pair of closely adjacent counter-rotating collapsing rolls mounted in alignment with said forming rolls to receive the beaded blank thererrom, said collapsing rolls collapsing said bead into a triple-thickness fold with said rounded edge disposed closely adjacent to and in transverse alignment with said one score line.

7. The apparatus of claim 6 wherein each of said pairs of forming rolls comprises a first roll having an annular recess and a second roll having a peripheral forming projection which extends into said recess and presses the adjacent portion of the advancing blank into said recess to form said continuous bead therein.

8. The apparatus of claim 7 wherein said second roll comprises a forming ring from which said forming projection extends, and a clamping ring adjacent thereto which engages the scored portion of said blank and presses said scored portion against the adjacent surface of said first roll to grip said scored portion during the forming of said continuous bead in said blank.

'9. The apparatus of claim 8 wherein said clamping ring is supported against the adjacent surface of said first roll by flexible and resilient means to thereby cushion the grip of said first roll and said clamping ring on said scored blank portion and insure against possible damage thereto during the forming of said bead.

19. The apparatus of claim 9 wherein said forming ring is provided with a peripheral recessed portion adjacent to and spaced from the unscored portion of said tblank on the opposite side of said head from said scored portion, whereby the additional metal needed for the forming of said bead is drawn from said unscored blank portion While said scored blank portion is gripped between said clamping ring and said first roll.

References Cited by the Examiner UNITED STATES PATENTS 2,27 9,667 4/ 1942 Forsberg 113-120 2,495,294 1/1950 Socke 113-120 2,6603 32 11/1953 Henchert 220-54 2,771,046 11/1956 Williams et al 11'3-11 2,791, 49 5/ 1957 Morand 220-54 2,944,498 7 /'1960 Renard 113-11 3,021,805 2/ 1962 Henchert 113-120 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner.

Claims

1. APPARATUS FOR FORMING A FOLDED BEAD ADJACENT A TEAR STRIP IN A FLAT METAL CONTAINER BODY BLANK, SAID TEAR STRIP BEING DEFINED BY A PAIR OF PARALLEL SCORE LINES WHICH ARE PERPENDICULAR TO THE SIDES OF SAID BLANKS, COMPRISING AT LEAST ONE PAIR OF CLOSELY ADJACENT COUNTER-ROTATING FORMING ROLLS BETWEEN WHICH SAID BODY BLANK IS ADVANCED, ONE OF SAID ROLLS HAVING AN ANNULAR RECESS AND THE OTHER OF SAID ROLLS HAVING A PERIPHERAL FORMING PROJECTION WHICH EXTENDS INTO SAID RECESS AND FORCES THE ADJACENT PORTION OF SAID ADVANCING BLANK INTO SAID RECESS TO FORM SAID SHALLOW BEAD IN SAID BLANK, SAID BEAD BEING PARALLEL AND ADJACENT TO ONE OF SAID SCORE LINES, AT LEAST ONE PAIR OF CLOSELY ADJACENT COUNTER-ROTATING REFORMING ROLLS ADJACENT TO AND IN ALIGNMENT WITH SAID PAIR OF FORMING ROLLS SO THAT SAID BLANK IS ADVANCED THEREBETWEEN, ONE OF SAID REFORMING ROLLS HAVING AN ANNULAR REFORMING RECESS AND THE OTHER OF SAID REFORMING ROLLS HAVING A PERIPHERAL REFORMING PROJECTION WITH A SHARPLY CURVED CORNER WHICH EXTENDS INTO SAID REFORMING RECESS TO PRESS SAID SHALLOW BEAD INTO SAID REFORMING RECESS AND TO REFORM IT INTO SAID RELATIVELY DEEP BEAD HAVING A SHARPLY CURVED CORNER, AND MEANS MOUNTED ADJACENT TO SAID REFORMING ROLLS FOR COLLAPSING THE REFORMED BEAD INTO A TRIPLE THICKNESS FOLD WITH THE ROUNDED EDGE OF SAID SHARPLY CURVED CORNER DISPOSED CLOSELY ADJACENT TO AND IN TRANSVERSE ALIGNMENT WITH SAID ONE SCORE LINE.