U.S. patent number 3,850,340 [Application Number 05/272,060] was granted by the patent office on 1974-11-26 for nestable container and apparatus for and method of making same.
This patent grant is currently assigned to Reynolds Metals Company. Invention is credited to Robert F. Bublitz, Frederik A. Siemonsen.
United States Patent |
3,850,340 |
Siemonsen , et al. |
November 26, 1974 |
NESTABLE CONTAINER AND APPARATUS FOR AND METHOD OF MAKING SAME
Abstract
A nestable container and an improved apparatus for and method of
making same are provided wherein a blank is drawn to define a drawn
container which is reverse redrawn to form the nestable container
which has a side wall and an annular planar flange extending
therefrom with a toroidal bead extending from the flange and having
at least a portion thereof arranged within and beneath the
peripheral edge of the flange. The container is adapted to be
nested in a substantially identical container so that the toroidal
bead separates the flange from the flange of a substantially
identical container when the container is nested in the
substantially identical container.
Inventors: |
Siemonsen; Frederik A.
(Richmond, VA), Bublitz; Robert F. (Chester, VA) |
Assignee: |
Reynolds Metals Company
(Richmond, VA)
|
Family
ID: |
27375481 |
Appl.
No.: |
05/272,060 |
Filed: |
July 14, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
92446 |
Nov 24, 1970 |
3695084 |
|
|
|
86866 |
Nov 4, 1970 |
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Current U.S.
Class: |
220/658;
206/519 |
Current CPC
Class: |
B21D
51/10 (20130101); B65D 1/26 (20130101); B65D
21/0233 (20130101); B31B 50/592 (20180501) |
Current International
Class: |
B31B
43/00 (20060101); B65D 1/22 (20060101); B65D
1/26 (20060101); B21D 51/00 (20060101); B21D
51/10 (20060101); B65D 21/02 (20060101); B65d
007/48 (); B65d 021/02 () |
Field of
Search: |
;220/97C,97F,74
;229/43,48T |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lowrance; George E.
Attorney, Agent or Firm: Glenn, Palmer, Lyne, &
Gibbs
Parent Case Text
This application is a divisional of applicants' copending patent
application Ser. No. 92,446, filed Nov. 24, 1970 now U.S. Pat. No.
3,695,084 which is in turn a continuation-in-part of applicants'
copending patent application Ser. No. 86,866, filed Nov. 4, 1970
now abandoned.
Claims
What is claimed is:
1. A container comprising
a. a side wall,
b. an annular flange extending outwardly from said side wall,
1. said annular flange having a substantially planar top surface
and a bottom surface,
c. an outer arcuate portion having an outer surface adjoining said
substantially planar top surface and an inner surface adjoining
said bottom surface,
d. and a reverse toroidal bead adjoining said outer arcuate
portion,
1. said bead having a first annular increment facing toward said
side wall so that the extension of said inner surface becomes the
first annular increment of said bead and a second annular increment
facing away from said side wall so that the extension of said outer
surface becomes the second annular increment of said bead,
2. said bead lying beneath the substantially planar top surface and
having at least a portion thereof arranged within and beneath the
outer peripheral edge of said outer surface,
e. and said outer arcuate portion providing vertical spacing
between said flange and said bead.
2. A container as set forth in claim 1 in which said bead has a
double thickness throughout at least a portion of its
cross-sectional outline.
3. A container as set forth in claim 1 in which said first annular
increment of said bead is arranged substantially adjoining the
bottom surface of said annular flange by a distance which is less
than the cross-sectional radius of said bead.
4. A container as set forth in claim 1 in which said side wall
comprises a substantially frusto-conical side wall and said bead
also has a portion thereof arranged outwardly of the outer
peripheral edge of said outer surface, said container being adapted
to be nested in a substantially identical container so that said
bead separates said flange from the flange of a substantially
identical container when the container is nested in the
substantially identical container.
5. A container as set forth in claim 1 having a thermoplastic
material defining its inside surface and having a thermosetting
material defining its outside surface.
6. In combination: a container and a closure for said container;
said container comprising:
a. a side wall,
b. an annular flange extending outwardly from said side wall,
1. said annular flange having a substantially planar top surface
and a bottom surface,
c. an outer portion having an outer surface adjoining said
substantially planar top surface and an inner surface adjoining
said bottom surface,
d. and a reverse toroidal bead adjoining said outer arcuate
portion,
1. said bead having a first annular increment facing toward said
side wall so that the extension of said inner surface becomes the
first annular increment of said bead and a second annular increment
facing away from said side wall so that the extension of said outer
surface becomes the second annular increment of said bead,
2. said bead lying beneath the substantially planar top surface and
having at least a portion thereof arranged within and beneath the
outer peripheral edge of said outer surface,
e. said outer arcuate portion providing vertical spacing between
said flange and said bead,
f. and means sealing said closure against said substantially planar
top surface.
7. A combination as set forth in claim 6 in which said nestable
container has a thermoplastic coating comprising its inside surface
and said sealing means comprises a portion of said coating on said
top surface heat sealed against said closure.
Description
BACKGROUND OF THE INVENTION
Previously proposed containers made of comparatively thin gauge
materials such as metallic foil, for example, are generally
deficient because the peripheral flange extending from the top wall
of each of these containers has an inadequate sealing area which
makes it difficult to provide a satisfactory fluid-tight closure
for each of these containers. Further, it is often necessary to
provide special offset portions in the side walls of these previous
containers to enable dispensing thereof using automatic equipment.
In addition, the use of thin gauge materials together with the poor
beads provided on peripheral flanges of these previous containers
makes reclosure of these containers very difficult.
Currently used apparatus and methods for producing drawn containers
are usually satisfactory when working with comparatively heavy
gauge materials but cause excessive scrap when applied to the
making of thin gauge containers using hardened metallic foil
stock.
SUMMARY
This invention provides an economical container made of thin gauge
materials and an improved apparatus and method for making such a
container from a blank of hardened metallic foil wherein each blank
is drawn to define a drawn container which is reverse redrawn to
form a nestable container which has a side wall and an annular
planar flange extending therefrom with a toroidal bead extending
from the flange and having at least a portion thereof arranged
within and beneath the peripheral edge of the flange. The container
is adapted to be nested in a substantially identical container so
that the toroidal bead separates the flange from the flange of a
substantially identical container when the container is nested in a
substantially identical container. Thus, the placement and
construction of the toroidal bead gives additional rigidity to the
flange of its container and enables easy dispensing of each
container from a stack of nested containers.
Other details, uses, and advantages of this invention will become
apparent as the following description of the embodiment thereof
presented in the accompanying drawings proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings show a present preferred embodiment of
this invention, in which
FIG. 1 is a perspective view of the container of this
invention;
FIG. 2 is an enlarged fragmentary cross-sectional view taken on the
line 2--2 of FIG. 1;
FIG. 3 is an exploded perspective view with parts in cross section
and parts broken away particularly illustrating a closure partially
unfastened from a planar flange extending from the side wall of the
container and illustrating a reclosure lid which is adapted to be
used on the container;
FIG. 4 is a perspective view with parts broken away illustrating a
dispensing device operatively associating with a stack of nested
containers of this invention to provide dispensing of individual
containers from the bottom of such stack;
FIG. 5 is a fragmentary end view particularly illustrating the
manner in which an arm of the device of FIG. 4 operatively
associates with the flanges and beads comprising a plurality of
stacked containers;
FIG. 6 is a fragmentary cross-sectional view taken essentially on
the line 6--6 of FIG. 4;
FIG. 7 is a perspective view of a flat blank used to make the
container of FIG. 1;
FIG. 8 is a perspective view with a portion broken away showing the
blank of FIG. 7 partially drawn to form a drawn container;
FIG. 9 is a perspective view with a portion broken away
illustrating the drawn container of FIG. 8 partially redrawn in a
reverse direction;
FIG. 10 is a perspective view with a portion broken away of the
container construction of FIG. 9 completely redrawn to define a
bottom wall and side wall while leaving a tubular wall portion
extending outwardly from an annular flange provided at the top of
its side wall prior to forming the tubular wall portion to define
the toroidal bead and the completed container of FIG. 1;
FIG. 11 is a cross-sectional view taken on the line 11--11 of FIG.
1 and drawn to the same scale as the container construction of FIG.
10;
FIG. 12 is an enlarged fragmentary cross-sectional view
illustrating cooperating components of a forming apparatus used to
form the tubular wall portion to define the toroidal bead and
illustrating the cooperating components at the beginning of the
bead-forming action;
FIG. 13 is a fragmentary cross-sectional view similar to FIG. 12
illustrating the positions of the cooperating components of the
bead-forming apparatus once the toroidal bead has been formed;
FIG. 14 is a fragmentary cross-sectional view illustrating an
exemplary embodiment of the apparatus used in making the container
of FIG. 1 prior to the beginning of the forming action and
illustrating an elongated strip or web of metallic material
arranged between cooperating die sets of the forming apparatus;
FIG. 15 is a view of the apparatus of FIG. 14 with the die sets
partially moved together and operating to draw a blank (which was
sheared upon initially moving the die sets together) to define a
drawn container with the partial movement of such die sets being
sufficient to define the container of FIG. 8;
FIG. 16 is a view similar to FIG. 15 illustrating the die sets in a
further stage whereupon such assemblies have moved together
sufficiently to define the reverse redrawn container construction
illustrated in FIG. 10; and
FIG. 17 illustrates the position of the cooperating die sets after
forming of the toroidal bead at the periphery of the annular flange
extending from the top edge of the side wall of the reverse redrawn
container to thereby define the completed container of FIG. 1.
DESCRIPTION OF ILLUSTRATED EMBODIMENT
Reference is now made to FIG. 1 of the drawings which illustrates
an exemplary nestable container of this invention which is
designated generally by the reference numeral 10. The container 10
has a bottom wall 11 and a frustoconical side wall 12 which has an
annular flange 13 extending outwardly from the top edge
thereof.
The flange 13 has a planar annular top surface 14 adjoined at
opposite ends by an inner arcuate portion 14A and an outer arcuate
portion 14B, see FIG. 2. A toroidal bead 15 extends from the flange
13 and has at least a portion 16 arranged within the peripheral
outline or peripheral circular edge 17 of the flange 13, i.e., the
portion 16 is within a right circular cylinder having a diameter
which coincides with edge 17. The bead 15 has a double thickness
throughout at least a portion of its cross-sectional outline and as
indicated at 20.
The portion 16 of the bead 15 which is arranged within the
peripheral outline of the flange 13 is arranged substantially
adjoining the bottom surface 21 of the flange 13. In particular,
the top surface of bead 15 is arranged beneath the plane of the
bottom surface 21 by a distance which is less than the
cross-sectional radius R of the bead 15.
As will be apparent from FIG. 2 of the drawings, substantially all
of the planar annular top surface 14 is usable to provide a sealing
surface area for a lid or closure such as the exemplary closure 22
shown in FIG. 3; and, the closure 22 may be fastened against
surface 14 using techniques known in the art. The surface 14 has a
large area which is greater than the major portion of the area of a
top plan view of the flange 13 with its bead 15. The surface 14 has
an area which is substantially larger than a similar seal area of
about half this size which is available on metallic foil containers
proposed heretofore.
Not only does the container 10 have a large seal area provided on
its annular flange 13 but the construction and arrangement of the
toroidal bead 15 also effectively supports the flange 13 to thereby
increase its strength and rigidity. In addition, the provision of
toroidal bead 15 which has substantial strength enables a reclosure
lid, such as the lid 23 illustrated in FIG. 3 to be easily placed
on the container 10 once the closure 22 has been removed and only a
portion of the contents of the container removed.
The container 10 may be made of any suitable material; however, it
is preferably made of metallic foil such as 3003-H19 aluminum foil
which may have a wall thickness in the range of 0.0035 inch, for
example. The container 10 is preferably made from a flat blank
which may have suitable layer means such as a coating on either one
or both of its surfaces. The container 10 is preferably made by
first drawing the blank to define a container and the container is
then reverse redrawn. During the return of the cooperating forming
dies used to make the container to their initial position following
the reverse redrawing action, the toroidal bead 15 is formed in the
peripheral flange 13 and it will be appreciated that such bead is
in essence a reverse bead. With such a reverse bead the first
annular increment of metal, such as annular increment 19, see FIG.
2, always faces toward the side wall 12 of the container.
The container 10 may have a thermoplastic material in the form of a
coating, layer, or the like defining its inside surface. The
thermoplastic material, such as a thermoplastic vinyl, may be
locally heated and used as the adhesive means for heat sealing the
closure 22 against the top surface 14. The container 10 may also
have a suitable protective thermosetting material in the form of a
coating or a laminated layer defining its outside surface.
The inside of the side wall 12 of the container may have one
appearance or color and the outside of such side wall may have
another appearance or color. Upon forming the reverse toroidal bead
15 the two colors are presented one to the other in contrast. Thus,
the appearance of the outside surface of the bead will be the same
as the outside surface of the container and this is arranged
immediately adjacent the top planar surface which has the same
appearance as the inside surface of the container.
The container 10 may be easily dispensed from a stack of nested
containers using a dispensing device such as the device designated
generally by the numeral 24 in FIG. 4 of the drawings and such
device may comprise automatic dispensing machinery. The device 24
has a pair of parallel arms 25 arranged on opposite sides thereof
and the arms 25 have forward portions or surfaces 26 which are
adapted to support the bottom surface of the toroidal bead 15 of
each container.
A stack of containers may be suitably supported to prevent
horizontal movement thereof essentially as illustrated at 27 in
FIG. 4 whereupon the arms 25 are reciprocated forwardly by an
eccentric cam mechanism 30 of the device 24 causing wedge-shaped
portions 31 of the arms 25 to move in the space 32 defined between
container 10 and a substantially identical container 10 stacked
therebeneath. Thus, the lowermost container 10 is dispensed from
the stack 27 onto a suitable means such as a conveyor or the like
(not shown) for advancement of the empty container to a filling
station or other suitable station for further processing. The
dispensing is achieved by moving the arms 25 forwardly in the
direction of the arrow 33 causing the wedge-shaped portions to move
into an associated space 32 and causing the bottom surface 34 of
the bead 15 of a container 10 nested within the lowermost container
10 to be supported on a surface 35 of arms 25 to thereby support
the entire stack 27 of containers 10. The arms 25 are then
reciprocated rearwardly by the cam mechanism 30 in a direction
opposite the direction of the arrow 33 causing the entire stack to
drop onto the surfaces 26 enabling the entire procedure to be
repeated and thereby enable dispensing of individual containers 10
from the bottom of stack 27.
From the above description, it is apparent that the bead 15 serves
to reinforce the flange 13 and assure that the surface 14 retains
its planar form. In addition, the construction and arrangement of
the bead 15 with respect to the planar surface 14 enables the
flange 13 to be used as a spacing means having a height which
defines the space 32 within which the wedge-shaped portions 31 of
the reciprocating arms 25 may be freely moved whereby the
containers 10 may be automatically dispensed. Further, the bead 15
assures that once a plurality of containers are stacked together in
nested relation a space is provided between the side walls 12 of
adjoining containers, see FIG. 6, whereby the containers 10 may be
more easily dispensed.
The container 10 illustrated in FIG. 1 preferably is made using the
apparatus and method of this invention, which is designated
generally by the reference numeral 37 in each of FIGS. 14-17 of the
drawings. The apparatus 37 comprises a lower die set or structure
40 and a cooperating upper die set or structure 41 and such die
sets may be readily used on a die press of standard
construction.
The lower die set 40 comprises a fixed support 42, see FIG. 14,
which has a die holder 43 fixed thereto and die set 40 also has a
cushion 44 fixed to the support 42. The cushion 44 has a plurality
of cylindrical bores 45 extending vertically therethrough with each
bore receiving a pressure pin 46 therethrough and the cylindrical
surfaces defining the bores 45 support the pins 46 for axial
sliding movement vertically. The die holder 43 has a wear bushing
or sleeve 47 fixed thereto which may be considered as defining an
inside cylindrical surface 50 for such die holder.
The die set 40 has a curling ring 51 supported concentrically
within the die holder 43 and the curling ring has an outside
surface 52 which is slidably supported for vertical movement along
the cylindrical surface 50. The curling ring 51 also has a portion
which is particularly adapted to define the reverse toroidal bead
15 in the container 10 and such portion will be described in detail
subsequently.
The die set 40 has a first die member which, in essence, is a dual
purpose die member 54 and such die member has an outside forming
surface 55 of right circular cylindrical configuration and an
inside forming surface 56 of substantially frustoconical
configuration. The die member 54 is fixed to a shaft assembly 57
which may be actuated using any suitable means to move the member
54 vertically upwardly and downwardly relative to the fixed support
42 of its die set 40.
The shaft assembly 57 has an outer cylindrical surface 60 which is
supported for vertical sliding movements by a cylindrical wear
sleeve 61 which is axially confined in the cushion 44 by a pair of
snap rings 62 arranged at its opposite ends. The member 54 also has
a member 63 which is fixed thereto and includes a forming portion
64 which has a contoured forming surface 65. The portion 64 is
arranged adjacent the bottom edge of the frustoconical inside
forming surface 56 and its contoured surface 65 is used to define
the contoured configuration 11A in the periphery of the bottom wall
11 of the container 10, see FIG. 11.
The die set 40 also has a female blanking die 70 which is attached
to the die holder 43 by a plurality of threaded bolts 71 and a
spacer 72 is disposed between the bottom surface of the blanking
die 70 and a supporting shoulder 73 on the die holder 43 to assure
correct positioning of the blanking die 70. The blanking die 70 has
an inside cutting edge 74 which, in this example of the invention,
has a circular outline.
The upper die set 41 comprises a support structure 75 which has a
punch holder 76 fixed to structure 75 by a plurality of threaded
bolts 77 and a plurality of dowel pins 80 are provided to assure
that the punch holder 76 is correctly aligned in the structure 75
prior to attachment thereof by the threaded bolts 77. The die set
41 has a holding ring 81 which is attached to the punch holder 76
by a plurality of threaded bolts 82 and another die member 84 which
may be referred to as the second die member of the apparatus 37 is
provided and fixed to the holding ring 81 by a plurality of
threaded bolts 85. The die member 84 may be considered a blanking
punch inasmuch as it has a cutting edge 86 of circular outline
which is adapted to cooperate with the cutting edge 74 of the
blanking die 70.
The upper die set 41 has a wear sleeve 90 which has its lower edge
supported on a shoulder 91 of its die member 84 and such sleeve is
suitably fixed to prevent axial movement thereof. The sleeve 90 has
a cylindrical inside wear surface 92.
The upper die set 41 also has a blank holder 93 which has an
outside cylindrical surface 94 which is slidably supported on the
surface 92 of the wear sleeve 90 and inside forming surface 95 of
the die member 84 which is aligned with surface 92 and vertically
therebeneath. The blank holder 93 has an inside cylindrical surface
96 and an annular shoulder 97 is provided as an integral part of
holder 93 and projects radially inwardly from the inside surface
96.
The die set 41 includes a forming punch 100 which is fixed to the
punch holder 76 by a threaded bolt 101. The bolt 101 has a
longitudinal passage 101A extending therethrough to assure that air
is not trapped between the forming surfaces of punch 100 and the
container being formed. A spacer 102 and a stop ring 103 are
interposed between the punch holder 76 and the punch 100. The stop
ring 103 has a surface 104 which projects radially outwardly beyond
the spacer 102 and is adapted to engage shoulder 97 of the blank
holder 93 to limit the downward movement of such blank holder. The
upward movement of the blank holder 93 within the punch holder body
76 is controlled by an annular ring 105 and in a manner to be
described in detail subsequently.
The punch holder 76 has an inner wear sleeve 106 and a larger
diameter wear sleeve 107 which are suitably fixed in position
against surfaces 110 and 111 respectively of the punch holder 76.
The ring 105 has a seal construction 112 carried within an
associated groove 105A and the seal construction 112 supports the
inside surface of the annular ring 105 for sliding movement along
the outside surface of the wear sleeve 106. The member 105 also has
another seal construction 114 which is suitably supported in a
groove 105B provided in the outside periphery of the member 105 and
the seal construction 114 slidably supports the outside surface of
member 105 along the inside surface of the wear sleeve 107.
During operation of the apparatus 37 with its cooperating die sets
40 and 41, a fluid (air in this example) under pressure is supplied
and maintained in an annular chamber 115 defined between sleeves
106 and 107. The air in chamber 115 is provided in a controlled
manner as determined by the operating cycle for the press in which
the apparatus 37 is used to maintain pressure on the top surface
116 of the member 105 and thereby maintain a pressure on the blank
holder 93 to resist vertical axial movement thereof within the
annular chamber 115.
To assure proper operation of the apparatus 37 a plurality of vent
passages 118 are provided through die holder 43 and sleeve 47 of
the lower die set 40. A plurality of vent passages 119 are also
provided in the horizontally extending flangelike portion of member
81 and the passages 119 vent the space between members 105 and
81.
The punch 100 has a convex substantially frustoconical forming
surface 120 and an outer annular forming surface 121 which
corresponds in configuration to the contoured configuration of the
surface 65 comprising member 63 fixed to the die member 54. The
surfaces 121 and 65 cooperate to define the contoured peripheral
edge 11A in the bottom wall 11 of the container 10 as previously
mentioned.
The upper die set 41 also has a stripper 122 which is supported
concentrically around the outside surface of the die member 84 and
the outside surface of the lower portion of the holding ring 81.
The stripper 122 has a plurality of rods 123 suitably fixed thereto
and each of such rods is supported for vertical sliding movement in
a cylindrical bore 124 provided in a horizontally extending flange
portion of member 81.
The upper end of each rod 123 has a piston 125 which is slidably
received within the inside cylindrical surface of a wear sleeve 126
which is fixed in position within an associated bore 127 in the
punch holder 76. Air under regulated pressure is supplied within a
chamber 130 defined by the inside surface of the wear sleeve 126
and such air acts against the top surface of each piston 125 to
control the position of its associated rod 123 and, hence, the
vertical position of the stripper 122. The air under pressure is
supplied into each piston chamber 130 through an associated
assembly 131 and a ring cap 132 is provided at the top of the punch
holder 76 and has seals 133 on opposite sides thereof to prevent
air leakage from the cylinders 130.
Having described the detailed construction and arrangement of the
various cooperating component parts comprising the lower die set 40
and the upper die set 41 of the apparatus 37, the detailed
description will now proceed with a description of the manner in
which the method of this invention is employed to define the
container of this invention and the manner in which the component
parts of the apparatus 37 cooperate to carry out this method.
In particular, a suitable web or strip of sheet stock S such as a
strip of 3003-H19 aluminum foil alloy having a thickness in the
range of 0.0035 inch is provided between the die sets 40 and 41 and
such die sets in this example will be described as comprising
components of a standard forming press. The support 42 and die
holder 43 are fixed to and comprise the bed of the forming press
while the structure 75 and punch holder 76 comprise the moving
press ram whereby it will be appreciated that with this
construction the forming members 54 and 84 are, in essence,
relatively movable toward and away from each other.
With the stock S interposed between the die sets 40 and 41, the die
set 41 is moved toward the die set 40 causing the die member 84 to
be used as a blanking punch whereupon its cutting edge 86
cooperates with cutting edge 74 of the female blanking die 70 to
shear a flat blank which, in this example of the invention, has a
circular peripheral outline and such blank is illustrated in FIG. 7
of the drawings and is designated generally by the reference
numeral 135. Simultaneously with this shearing or cutting action to
define the blank 135, a peripheral edge of such blank is clamped
initially between an annular clamping surface 136 on the curling
ring 51 and a cooperating annular clamping surface 137 on the die
member 84.
Continued movement of the die sets 40 and 41 toward each other
causes an annular clamping surface 140 defining the outer or top
edge of the die member 54 to clamp an inner annular portion of the
blank 135 against a cooperating annular holding surface 141 on the
blank holder 93. As the die sets are moved further together an
intermediate product or drawn container is defined which is
designated by the reference numeral 143 in FIGS. 8 and 15 even
though it will be seen that such container has not been completely
formed.
The drawn container 143 has a bottom wall 143A and a side wall 143B
and is defined by the outside forming surface 55 of the die member
54 cooperating with the inside forming surface 95 of the die member
84. During the drawing of container 143 the outer portion of the
blank 135 is clamped between the annular clamping surfaces 136 and
137, see FIG. 15, while the surfaces 140 and 141 define the bottom
wall 143A and serve to draw that portion of the blank 135 arranged
outwardly of the surfaces 140 and 141 through surfaces 136 and 137
to define the side wall 143B. The drawing action may be achieved
using a double action cushion system (not shown) which operates in
a known manner so that as the die set 41 is moved downwardly the
shaft assembly 57 and its associated die member 54 is moved
upwardly causing the drawing of container 143 between cooperating
forming surfaces 55 and 95 of the die members 54 and 84
respectively.
At the point in the forming of the drawn container 143 where the
major part of side wall 143B has been defined, i.e., the position
shown in FIG. 15, the punch 100 engages the bottom wall 143A of the
drawn container 143 to start forming the reverse redrawn container
10. The reverse redrawing is achieved by the convex frustoconical
surface 120 of the punch 100 cooperating with the concave
frustoconical surface 56 of the die member 54 and during this
reverse redrawing action the clamping surface 140 and the holding
surface 141 on the members 54 and 93 respectively define what may
be considered as an annular forming passage through which that
portion of the drawn container 143 initially arranged outwardly of
the peripheral outer edges of the surfaces 140 and 141 is drawn to
define the redrawn container 10 and essentially in the manner
illustrated in FIG. 16 of the drawing.
During the redrawing action the cooperating surfaces 56 and 120
define the side wall 12 of the container 10 and prior to completely
forming side wall 12 the container is redrawn so that for an
instant during redrawing it has the configuration shown at 145 in
FIG. 9. At the completion of the redrawing action the contoured
surface 121 of the punch 100 cooperates with the contoured surface
65 of member 63 to define the contoured peripheral configuration
11A in the bottom wall 11 of the container 10; and, the surfaces
140 and 141 cooperate to define the planar annular flange 13 of
container 10.
The bottom wall 11 and side wall 12 of the redrawn container 10 are
completed with the cooperating components in the positions
illustrated in FIG. 16 and it will be noticed that the annular
flange 13 defined between the surfaces 140 and 141 has a tubular
wall portion 144 extending to one side of the plane of the annular
flange 13. In this example, the tubular wall portion 144 extends
beneath the horizontal plane of flange 13.
At the completion of the reverse redrawing action (which is the
position of the cooperating die sets illustrated in FIG. 16 of the
drawings), the die set 41 is returned to its original position by
moving the ram of the forming press upwardly. During this upward
movement a portion of the curling ring 51 engages the lower edge of
the tubular wall 144 to form the reverse toroidal bead 15 and
complete the container 10.
The curling ring 51 is actuated by the pins 46 which are moved
simultaneously by the action of ram 46A engaging their lower end.
In addition, the construction of the components used to form the
bead cooperate to assure that the completed toroidal bead lies
beneath the plane of the flange 13 and has at least a portion
thereof arranged within and beneath the outer peripheral edge 17 of
such flange. Further, the curling ring is constructed so that the
portion thereof which engages the tubular wall portion 144 may
define the bead 15 which has either a single thickness or may have
a multiple thickness through portions thereof as viewed in cross
section.
Reference is now made to FIGS. 12 and 13 of the drawings which
illustrate in enlarged view parts of the curling ring 51 and
associated die members which enable the forming of the flange 13
and toroidal bead 15. In particular, it will be seen that the die
member 54 has an arcuate portion 150 as viewed in cross section
extending between its concave frustoconical forming surface 56 and
its clamping surface 140 and the arcuate surface portion 150
defines the inner arcuate portion 14A of the flange 13. The member
54 also has an arcuate portion 151 extending between its outer
forming surface 55 and clamping surface 140 and portion 151 is
defined by an arc having a larger radius than the portion 150 and
such larger radius assures the formation of the arcuate portion 14B
in the flange 13 without obstruction once the cooperating
components of the die sets are moved together in the manner
mentioned above.
The curling ring 51 has a concave curling surface 152 (as viewed in
cross section) one end of which terminates in a slightly rounded
wedge-like edge 153. The opposite end 154 adjoins a substantially
vertically extending cylindrical surface portion 155 of controlled
length. The surface 155 adjoins an inclined surface 156 which is
inclined at an angle which may be generally of the order of
10.degree. to 20.degree. from a horizontal plane defined by the
horizontal plane of the clamping surface 136.
Once the cooperating die sets 40 and 41 have formed the bottom wall
11 and side wall 12 of the container 10 with the wall portion 144
being arranged essentially in the position illustrated in FIG. 16,
the press is returned to its initial position whereupon pins 46
restore the curling ring to its original position causing edge 153
to engage a lower edge 160 of the wall portion 144 as illustrated
in FIG. 12 of the drawings and commence curling of the wall portion
144 in what may be considered a reverse manner until the curled
bead 15 illustrated in FIG. 13 has been formed. During the last
increment of travel of the curling ring 51 the flange 13 is
maintained in a clamped manner between clamping surfaces 140 and
141 to thereby assure that the annular surface 14 remains planar
and has a maximum surface area. At the completion of the forming of
the bead 15 the outer arcuate portion 14B is formed in the flange
13 by compressing the formed bead 15 upwardly toward the bottom
surface 21 of the flange 13. Thus, the bead 15 is arranged
substantially adjoining bottom surface 21 and the cooperating
arrangement of the components of the die sets is such that the
toroidal bead is arranged substantially adjoining the bottom
surface 21 by a distance which is less than the cross-sectional
radius R of the bead 15.
With the container 10 completely formed, see FIG. 17, the stripper
122 is constantly yieldingly urged downwardly by its rods 123 which
are urged by air under pressure supplied to the top surface of
associated pistons 125 whereby the web or sheet S of material is
held firmly against the surface 74A of the female blanking die 70
until after die set 41 disengages die set 40. The sheet S is then
free of the die sets and may be suitably advanced a predetermined
increment and the forming operation repeated to define circular
blank 135, intermediate drawn container 143, and reverse redrawn
container 10 essentially as described in detail above.
The die sets 40 and 41 are then returned to their initial positions
so they are vertically spaced apart a distance greater than the
amount illustrated in FIG. 14 and such distance is greater than the
height of the completed container 10 to enable removal of the
completed container.
Referring to FIG. 17, it will be seen that member 63 with forming
portion 64 is threadedly fastened to the shaft assembly 57. Member
63 has a central opening 63A and a plurality of radially extending
openings 161 which together with an opening 162 extending axially
through the shaft assembly 57 provide venting to atmosphere during
forming of the container. The completed container 10 is removed
from within the die 54 of the lower die set 40 by moving shaft
assembly 57 upwardly thereby raising member 63 and container 10.
The raised container 10 may then be removed from the lower die set
40 by either a horizontal jet of air or mechanical fingers in
preparation for another forming cycle.
The apparatus 37 enables the forming of the container 10 by first
drawing the flat blank 135 to define the intermediate drawn
container 143 and prior to completely forming the side wall 143B of
such container 143, the redrawing action is commenced in a reverse
direction whereby the total stroke of the cooperating components of
the die sets 40 and 41 is kept at a minimum. In addition, the
unique cooperating arrangement of the components of the die sets
enables the forming of containers made of metallic foil which is in
a hardened condition whereby the completed container 10 is less
susceptable to damage and has greater structural strength.
The sheet stock S of metallic foil from which the reverse redrawn
container 10 is made and, hence, the blanks 135 sheared therefrom
may be coated with any suitable material or have a layer laminated
thereagainst. The layer or coating may be such that it serves as a
lubricant during the drawing and redrawing action while serving to
improve the scuff resistance of the final container.
Although the container 10 has been described as being made from a
sheet S of metallic foil which may either be coated or may have a
layer of material bonded against either one or both of its
surfaces, it will be appreciated that the container of this
invention may be made utilizing stock and blanks which are either
uncoated or made as a laminated construction such as a laminated
construction using paper, foil, plastics, or similar materials in
any desired combination and arrangement of layers. Further, the
apparatus and method may be used to form containers from such
laminated constructions.
The container 10 has a substantially circular peripheral outline
and a frustoconical side wall. In addition, such container is made
from a flat blank 135 having a circular peripheral outline.
However, it will be appreciated that the apparatus and method of
this invention may be used to make containers having different
configurations and using blanks having correspondingly different
configurations.
While present preferred embodiments of this invention, and method
of practicing the same, have been illustrated and described, it
will be recognized that this invention may be otherwise variously
embodied and practiced within the scope of the following
claims.
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