Controlled spin flow forming

A system and apparatus for roll forming to neck-in D&I cans ends and replace double necks and triple necks is disclosed. An externally disposed free roll is moved inward and axially against the outside wall of the open end of a trimmed can. A spring loaded interior support roller moves under the forming force of the free roll. This is a single operation where the can rotates and the free roll rotates such that a smooth conical necked end and flange are produced.

BACKGROUND OF THE INVENTION 
This invention relates to containers; the body for such containers being in 
the form of cylindrical one-piece metal can having an open end terminating 
in an outwardly directed peripheral flange merging with a 
circumferentially-extending neck portion (the can body being hereinafter 
referred to as a D&I can). Methods of forming said neck and flange in a 
D&I can body and to apparatus for forming the said peripheral flange and 
neck portion. 
The background for this disclosure relates to the way in which D&I can 
bodies are manufactured in drawing and then multiple ironing operations. 
For 20 years beverage containers have been made by a drawing and then 
multiple ironing processes in which the metal material is first drawn into 
a cup to establish the shape and a basic inside diameter and the cup is 
then pushed through a series of ironing rings which merely thin the side 
wall and do not appreciably affect the diameter. 
The cross-sectional configuration of the ironing ring includes a chamfer, a 
land and finally a relief angle. The ironing process begins on the chamfer 
and is completed by the land during which time no drawing takes place. The 
process is done at high speed under a coolant/lubricant flood in order to 
accommodate the severity of the operation especially the heat. These 
containers have to be washed and in some cases chemically treated to 
remove residual lubricant and improve corrosion performance of organic 
coatings and decoration subsequently applied to the container. Coatings 
are normally applied after the shell has been trimmed and washed free of 
lubricants and metal fines. 
The ironing steps result from the difference between the clearance between 
a punch and ironing ring land and the thickness of the metal sidewall. 
That clearance represents the amount to which the side wall of the 
container will be thinned. Usually, metal with no organic coating passes 
through three different ironing rings in a D&I operation during which ETP 
electrolytic of T-1 to T-5 temper tinplate or H19 aluminum container 
sidewall is reduced about 25% in the first pass, about 25% of its new 
thickness in the second pass, and about 40% of its new thickness in the 
last pass, while the metal and tooling are flooded with lubricant coolant. 
This operation increases the side wall length to several times that of the 
cup which was formed in an ordinary and separate one or two-draw 
operation. The cleaned and trimmed D&I can may then be necked and flanged 
in a separate apparatus and an independent operation. The grain 
orientation of the ironed sidewall is highly directional and the D&I can 
is subject to longitudinal cracking particularly at the radially extending 
flange. The purpose of the peripheral flange is usually to provide an 
element to which a can end is secured after the can has been filled, this 
securing being done by deforming the end flange of the can body together 
with a peripheral cover hook of the can end so as to form a double seam. 
Consequently, flange cracks are a problem to achieving a hermetic double 
seam. The neck enables the flange, and therefore the can end, to be of 
smaller diameter than if there were no neck; usually the radial depth of 
the neck is such that the double seam has an external diameter less than 
that of the cylindrical side wall. Necking also minimizes the radial 
extent of the flange thus helping to resist flange cracking. 
In some types of metal lids, such as those having easily opened ends of the 
so-called "ring pull" or "tab" type, the end to be seamed on to the flange 
of the can body is preformed with the scored opening feature. These 
opening features often determine the diameter of the end and only recently 
has the tab-type been reduced in size to permit ends as small as 202 being 
2 and 2/16" across the double seam (can makers conventional terminology). 
The end neck may serve another purpose, which is to provide a convenient 
means whereby a carrier can engage the container; such carriers are 
designed to hold a plurality of containers and may be of, for example, 
paperboard or a flexible plastic material. The type of carrier which 
engages the neck of a container of the kind with which this disclosure is 
concerned may include a horizontal web in which there are a plurality of 
holes, the periphery of each hole engaging below the above-mentioned 
container double end seam so as to support the container wholly or partly 
thereby. Where the container body is necked, the neck can be so shaped as 
to provide some measure of support and/or restraint for the carrier web 
around the hole in the latter, and to assist in locking the container to 
the web until the user wishes to pull it away from the carrier. Similarly, 
a reduced neck allows the cans to be held in close parallel relation thus, 
minimizing the total space needed to hold the containers. In addition, the 
necked end can can be designed to stack against the bottom of a similar 
container for ease of shipping. 
Various methods have been used and proposed for forming an end neck and 
flange on a one-piece can body. Some methods involve molding the neck 
and/or the flange by means of circumferentially extending molds. Die 
necking has also been used to longitudinally move a die against the end of 
a supported D&I can to force same to a smaller diameter by means of the 
application of the die. Other methods involve rolling or spinning the neck 
and/or flange, using an external spinning roll of a given shape 
co-operating with an internal member of a companion shape within the can 
body. In these latter methods, the can body is supported rigidly by an 
internal mandrel or the like; the internal member may be a spinning roll, 
pilot or it may be the mandrel which supports the can body. In one such 
method the neck and flange are formed simultaneously in a can body 
supported internally and rigidly by a mandrel or chuck of an 
expanding/collapsing type, the neck and flange profile being formed by 
external spinning rolls co-operating with this mandrel. 
In another method, the can body is supported internally by an anvil and 
endwise by a spinning pilot, the neck and flange being formed by a 
profiled, external spinning roll which deforms the can body into a groove 
formed on the pilot and anvil, the roll being moved axially of the can 
body. 
In all these previously-proposed methods the final profile of the neck and 
flange is determined by the set profiles of the tool elements used for 
forming them, in that the tool elements (i.e., spinning rolls, mandrels, 
anvil etc. are provided rigidly with fix working surfaces shaped to 
conform with the ultimate shape of the neck and/or the flange, and the 
metal of the can body is deformed into conformity with these profiles. It 
is thus necessary, if a different shape is required to change the tools so 
as to provide differently profiled tool elements. 
A method such as that mentioned above, in which an expanding mandrel is 
used enables end flanges and neck portions to be produced reliably and 
economically even on can bodies made in the thinner and harder metals 
currently in favor, in particular double-reduced plate which is usually 
tinplate, but which may, for example, be aluminum, mild steel or 
blackplate suitably treated but not necessarily plated with another metal. 
The present invention is also especially suitable for use with these 
thinner and harder double reduced or work hardened materials. 
The problems with the rolling or spin forming of tooling used in the prior 
art concerns the weak and relatively unsupported upper sidewall metal of 
the open end of a D&I can body. Such metal is usually very thin around 
0.004" to 0.006", highly worked during ironing and highly grain oriented. 
Merely placing a tool with the desired profile inside the container and 
applying a similarly shaped roller to the outside of the container while 
same is spun does not give the metal during the forming operation adequate 
or complete support to prevent wrinkling, cracking, buckling, crushing or 
tearing. This uncontrolled or unsupported application of radial side force 
on the thin metal sidewall of the open end is unacceptable particularly in 
connection with the higher temper (H19, T5 or double reduced) materials in 
connection with operations performed at high speeds wherein the rate of 
production of the containers during necking and flanging is more than 
several hundred per minute. No known method for providing adequate support 
or complete control of the metal during forming was known whereby the 
problems stated in connection with the forming of necked and flanged 
containers were overcome. 
OBJECTS OF THE DISCLOSURE 
It is an object of the disclosure to provide a holding mandrel and roller 
combination which cooperate to overcome the problems of metal damage 
during a necking and flanging operation by means of spin flow forming. 
It is another object of the invention to disclose a holding mandrel which 
co-acts with the forming roller to provide continuous support for the 
metal being spin flow formed into the neck and flange for a thin wall D&I 
can. 
It is still a further object of the invention to disclose a combination of 
forming roller and holding mandrel which produce a container having a 
unique, smooth, conical necked in portion extending from the full diameter 
of the sidewall into the root of the neck and outwardly therefrom to a 
terminating flange suitable for hermetic double seaming with a small 
diameter lid. 
SUMMARY OF THE DISCLOSURE 
Disclosed is a unique tool for flow spin forming the opened end of thin 
wall D&I cans, a method for using that tool and a unique container 
configuration easily obtainable at commercial speeds by application of 
that tool with that method.

DETAILED DESCRIPTION OF THE DISCLOSURE 
An apparatus 10 including a externally positioned roller 11 mounted on a 
mandrel 12, supported for full rotation by bearing 13 captured between the 
roller 11 and mandrel 12 to allow roller 11 to freely rotate with respect 
to its mounting yoke 14. The contour of the nose of periphery of roller 
11, as shown in FIG. 1 includes flat 11a, a leading portion 11b and a 
trailing port 11c. As can be seen in the Figure, the mandrel 12 has a 
greater axial length than the mounting hub 11d for the peripheral roller 
11 whereby the roller 11 is free to slide, along the mandrel 12 against 
the urgings of a coil compression spring 12a which sets about mandrel 12 
in reaction to axial thrust applied to the roller 11 during spin flow 
forming. The yoke 14 is mounted for controlled movement toward and away 
from the axis A of the apparatus 10 such as, for example, by a timed cam 
means. 
The spinning device to drive the D&I can to be necked and flanged by spin 
flow forming is composed of a can support 15 which includes a gear drive 
16 and its extended hub 16a, mounting bearings 17 within the extended ends 
of the hub 16a, which ride upon a fixed support shaft 18 and a D&I can end 
holder 19. The bearings 17 are disposed between shaft 18 and the hub 16a 
of gear 16. Shaft 18 is merely a fixed support and as such is not 
drivingly rotatable along its axis A. Holder 19 is shaped with a chamfered 
leading edge portion 19a designed to first engage the open end of a 
trimmed D&I can and then to support same for rotation about axis A in 
connection with the drive of gear 16 through the hub 16a therefore. Holder 
19 is also free to slide axially relative to fixed shaft 18 but is 
resiliently biased into the open D&I can end by springs 20 (only one of 
which is shown in FIG. 1). The springs 20 are of the compression coil type 
and are captured in counter bored holes for controlled alignment and 
positioning. A driving collar 21 is mounted on hub 16a and arranged to 
rotate about shaft 18 in accordance with the drive from gear 16. More 
particularly, collar 21 has a set screw 21a to attach collar 21 to hub 16a 
and hold same adjacent gear 16 so that collar 21 is disposed with its 
counter bored holes 21b set to receive the springs 20 and locate same as 
to extend to holder 19. For that purpose, there is a cooperating counter 
bored hole 19b therein set to receive the other end of spring 20, shown in 
FIG. 1, whereby holes 21b and 19b opposite lead portion 19a are opposite 
each other and aligned to carry spring 20. 
Shaft 18 also carries a fixed inner roller assembly 22 which is mounted on 
an enlarged diameter (relative to the diameter of shaft 18) eccentrically 
disposed end 18a of shaft 18. More particularly, end 18a is cylindrical 
and offset to one side of the axis A such that it has a center line B. The 
offset is such that it is positioned at the center of the larger diameter 
of end 18a whereby the end 18a has one side which is in line with the side 
of shaft 18 and the other side which is offset relative thereto. Between 
the sides of end 18a and the roller assembly 22 there are bearings 23 
which are a part of roller assembly 22 and support same for free rotation 
about axis B. The roller assembly 22 also includes a roller sleeve 24 
having an inner diametrical surface 24a supported on bearings 23, an outer 
contoured surface 24b which is adapted to engage a part of the inside wall 
of the D&I can, a front face 24c and a rear face 24d. The latter is 
adapted to abut the portion 19a and more specifically, the face thereof 
when same is urged outwardly of collar 21. 
Roller assembly 22 is restrained from axial movement relative to shaft end 
18a by an inner axial bearing 25 disposed between the roller sleeve 24, 
rear face 24d and the holder 19. More particularly, holder 19 includes a 
recessed inner bore 19c which provides space for receiving the axial 
thrust bearing 25 and thereby limits the motion of holder 19 axially 
outwardly in response to the urgings of springs 20 whereby in its 
outwardmost position (holder 19 to the right in FIG. 1) abuts at 19a near 
face 24d of the sleeve but really against thrust bearing 25. 
The outer end of sleeve 24 is maintained by means of a thrust bushing 26 in 
a form of a washer which during assembly is slid over end 18a and is held 
axially thereon by a retaining ring 27 disposed within a groove 18b 
circumscribed about the distal periphery of end 18a. Consequently, sleeve 
24 is held in position between the bushing 26 and the bearing 25 so its 
axial location, relative to end 18a is fixed. Bearing 25 acts as a stop 
for the outward axial motion of holder 19 but the location of bearing 25 
is defined by the hub 16a upon which gear 16 is carried. More 
specifically, the hub has bearings 17, as already mentioned, which ride on 
fixed shaft 18 and hub 16a extends to the right through attached collar 21 
to its end 16b which abuts bearing 25 and carries bearing 17 inside that 
end. In a manner well known, hub 16a is free to rotate relative to shaft 
18 but because of a keyed relationship between hub 16a and in particular a 
keyway 16c on hub 16a and 19d on holder 19 axial movement between holder 
19 and hub 16a is permitted even though holder 19 rotates with hub 16a. In 
the keyway, defined by 16c and 19d is a key 28 which acts like a spline to 
permit the axial motion of the holder 19 outwardly in response to the 
urgings of springs 20. 
The D&I can is supported by its bottom which includes vacuum. This, of 
course, is not the only way in which the container may be held during its 
rotation along the axis A but FIG. 1 illustrates a convenient means by 
which the bottom of a container may be supported along a specific axis as 
it is rotated. More particularly, there is a chuck assembly 29 which 
includes a gear 30 driven at the same speed and in a manner similar to 
that used to drive gear 16. For example, by a jack shaft with pinions (not 
shown). Gear 30 has a center hub 31 which is provided with an axially 
positioned vacuum passage to permit vacuum to pass therethrough for 
purposes of holding the bottom of the D&I can. Hub 31 is supported 
cantilever on a bearing 32 whereby gear 30 can rotate when driven about 
axis A. A cup 33 is mounted to the face 30A of gear 30 and extends 
outwardly therefrom along axis A toward the bottom of the D&I can. Cup 33 
is designed to carry an O-ring 34 within the inwardly (radial) rolled end 
thereof 33a in order to define a place against which the D&I can bottom 
can be sealed in order to maintain the vacuum established through the hub 
31. More particularly, hub 31 has an extending flange 31a against which 
the bottom of the D&I can rests whereby the lower side wall is sealingly 
engaged with the O-ring 34. 
In operation the yoke 14 carries peripheral roller 11 to engage the side 
wall of the open trimmed end of the D&I can between where same is 
supported by holder 19 and sleeve 24 while the D&I can is rotated between 
the hub 31 and the holder 19. The peripheral roller 11 is moved radially 
inward in response to controlled motion of yoke 14 and begins to define a 
conical necked-in end on the D&I can. More specifically, trailing portion 
11c of roller 11 bears against the sidewall of the open end of the D&I can 
camming the roller 11 axially to the left in accordance with arrow C. For 
this purpose the end on sleeve 24 is chamfered at corner 24e and same 
cooperates with the trailing part 11c to define the angle of the conical 
neck for the D&I can. Any reasonable obtuse (with respect to the inside 
wall) angle is obtainable. The spin flow forming of the D&I can due to 
inward motion (radially) of roller 11 would be uncontrolled except for the 
fact that holder 19 is spring loaded axially outward (to the right) to 
engage the radially inwardly moving end of axially slidable roller 11. 
More specifically, the lead portion 11b of roller 11 comes into contact 
with portion 19a on holder 19 so that same will be urged under the spring 
force of coil springs 20 against the chamfer 24e. 
It can now be appreciated that the force required to neck the end of the 
D&I can, can be maintained against the conically forming end by means of 
the cooperation between trailing part 11c and chamfer 24e both of which 
define the angle of the cone to be formed. The resistance to movement in 
the direction of arrow C of roller 11 by the contact between leading 
portion 11b and the portion 19a of holder 19 is essential. Throughout the 
forming of the conical end the motion radially inward of the yoke 14 which 
carries the roller 11 is similarly controlled. The axial motion in the 
direction of arrow C of the roller and the forming of the conical end 
between the roller 11 and the sleeve 24 are entirely controlled without 
any release of force against the container end during the spin flow 
forming. 
The offset between axis A and axis B is provided in order to permit removal 
of the necked container notwithstanding the larger diameter of assembly 
22. More particularly, the diameter to which the container is necked is 
still greater than the diameter of the assembly 22 whereby release of the 
conically necked D&I can from the chuck assembly 29 permits the container 
to tip relative to its axis A and slide over the offset of eccentric 
assembly 22. 
While a particular arrangement has been shown and described, skilled 
artisans will appreciate that the design of the drive mechanism, the chuck 
or even the offset eccentric roller assembly can be modified and still be 
within the scope of the claims which follow. More particularly, the 
invention herein is the control of the metal forming tools not their 
particular configuration or structural arrangement