Note: Descriptions are shown in the official language in which they were submitted.
~L;226~
AIR TRANSFER SYSTEM FOR A SHELL PRESS
The invention relates to an air transfer system,
and more particularly to an air transfer system for a
shell press having a blanking and forming die station
and a curling die station commonly operated therein.
Beverage cans, food cans and the like have a can
body and separately manufactured ends, which are
called shells that are sealed to the can Cody.
Generally, the shells are manufactured from sheet
steel, aluminum, or other acceptable material in a
series of presses, wherein the shell is blanked and
formed in one press and then transported to a second
press which curls the edges of the blanked an formed
shell. The uncurled shell has a peripheral edge that
is generally perpendicularly disposed to the main
body of the shell, and, before the shell is stacked
and then sealed to the beverage can it must first be
curled at its peripheral edge and then coated with a
sealant which forms a resilient gasket against the
can body.
A major problem currently existing in the
industry is directly related to the use of separate
presses to blank and form the shell and to curl the
shell. Depending upon the layout of the manufacture
in plant, the blanked and formed shells may first
have to be stacked one upon the other and then
transported to the curling die station to be curled,
or the situation may arise wherein it is necessary to
store stacked blanked and formed shells due to
unforeseen circumstances, for example, an inoperable
I
curler. In any event, the shapes of the blanked and
formed shells permit -them to be conveniently stacked
since one shell tightly nests within another.
However, because the blanked and formed shells
tightly nest one upon the other, it is virtually
impossible to mechanically cut an individual shell
from a tightly nested stack of shells. This requires
the shells to be stored in an unstacked state, which
requires considerable space and is time consuming,
costly and inefficient.
In some shell press installations, the blanking
and forming die station and curling die station are
in close proximity with one another so that the
blanked and formed shells may be transported to the
curling die station/ for example, by use of a convey-
or assembly. The shells are generally blanked and
formed from the strip stock in groups of twelve,
fourteen, or sixteen. For example, a group ox
sixteen may be blanked and formed from the strip
stock in two rows of eight, which rows are staggered
relative to each other to minimize the strip stock
skeleton remaining after the blanking and forming
operation. Since it is not practical to stack the
blanked and formed shells, it is necessary to keep
them separated from each other between the blanking
and forming die station and curling die station.
A typical prior art embodiment of the above
shell press installation comprises a double acting
press that blanks and forms the shells, a ring curler
for curling the blanked and formed shells, and a
conveyor assembly extending there between. The
blanked and formed shells may be delivered to the
conveyor assembly in one of two common ways. The
blanking and forming shell press may be designed to
tilt towards -the conveyor assembly so that the
blanked and formed shells slide from the press on-to
the conveyor for conveyance to the ring curler, or a
mechanical kicker-type device may be used with a
stationary blanking and forming shell press to eject
the blanked and formed shells onto the conveyor. In
this particular embodiment, the ring curler generally
comprises two rotating rollers between which the
shells pass to be curled.
though the above embodiment permits the
blanking and forming operation and the curling
operation to be performed in close proximity to each
other, certain problems and disadvantages exist such
as the requirement for additional space for the
conveyor assembly, frequent denting of shells by the
kicker device in ejecting the shells onto the convey-
or assembly, and the tendency of the ring curler to
produce shells having nonuniform curled edges.
Another typical prior art embodiment, which may
be a modification of the above described embodiment,
uses a die curler in place of the ring curler. Here
the blanked and formed shell is curled at a die
station, which is commonly housed in a press separate
from the blanking and forming shell press and operate
Ed independently thereof. The distance between the
blanking and forming shell press and the die curler
may be such that a conveyor assembly may be used -to
transport blanked and formed shells to the die
curler. Stacking for -transporting to the die curler
~167~
is not practical due to the tight nesting of a stack
of planked and formed shells.
Concerning the conveyance of parts between
different shaping operations, means other than
conveyor belt assemblies have been utilized, for
example, pneumatic systems which generally comprise a
large plenum and duct assembly. In these systems,
parts such as bottles, cans, records, silicon wailers
and -the like are transported along a guide track
overlying the ducts. The ducts have a plurality of
openings disposed therein and the plenum provides a
source of low pressure air which flows through the
ducts and out the openings to convey the part from
one area to another. This type of system poses
numerous disadvantages when adapted to a shell press
wherein a plurality of shells are formed simulate-
nuzzle.
Recalling from above, shells are blanked and
formed in groups of twelve, fourteen, or sixteen and
in rows which are staggered relative to each other
such that shells formed in one row overlap shells of
adjacent rows. Therefore, it is desirable to trays-
port alternate rows along different paths or tracks,
which may be disposed relative to each other in a
vertically adjacent manner. In such an arrangement,
it is not practical or efficient to utilize the
pneumatic systems of the prior art because of the
large size of the ducts that provide air flow to the
tracks. Such prior art systems would be difficult -to
adapt to a blanking and forming die station and a
curling die station operated in the same shell press,
and would also require an unideal amount of metrical and space.
Examples of such pneumatic systems may be wound
in US. Patents 3,87~,7~0; 3,975,057; 3,953,07~; 3,9~1,070;
3,293,414; and 3,645,581.
The present invention eliminates the disadvantages
and problems inherent in the prior art and provides certain
feature unique to a shell press. Particularly, there is
provided a shell press having a blanking and forming die
station and a curling die station operated by a common slide
assembly disposed in the shell press, thereby eliminating
the need of having to stack formed and blanked shells.
Since the shells are formed, blanked and curled
in the same shell press, the curled shells may be easily
stacked and, more importantly, easily cut mechanically
from a stack. A further advantage of utilizing a die
curler in the same shell press with a blanking and forming
die station is the -uniform shape of curled edges produced
by the die in contrast to the curled edges produced by a
ring curler.
Another feature of the present invention is the
provision of a unique pneumatic transfer system which is
compact and easily interfaced between the blanking and
forming die station and curling die station in the same
shell press.
In one form of the invention, the pneumatic
transfer system comprises two guide tracks extending
between the die stations in a double-deck arrangement.
Disposed in the upwardly facing surface of each of the guide
tracks is a hollow tube having a diameter much smaller than
the width of the guide track or the diameter of the shell
- 5 -
Mabel
being conveyed. Each hollow tU~Jc has a plurality of
uniquely shaped openings which provide air flow velocity
components in the direction of the curling station, and
each is connected to an air source which provides a flow
of high pressure air. Because Tao pneumatic system of the
present invention utilizes a very small diameter hollow
tube in place of the large plenum and duct assembly of
the prior art pneumatic systems, the pneumatic system of
the present invention is easily installed between a double-
deck guide track arrangement, thereby reducing space
requirements and costs.
The present invention minimizes the number of
dented shells caused by mechanical kicker-type devices in
ejecting the shells from a particular die station. Specie
focally, there is provided with the curling die station
an ejecting or escapement mechanism which directs a pus
of air against a curled shell to eject the shell from the
curling die station onto a guide track leading therefrom.
The present invention provides a shell press for
making shells for beverage cans and the like comprising
a blanking and forming die station and a curling
die station, both of which are operated by a common slide
assembly disposed in the shell press. An ejector may be
provided, according to an illustrated embodiment of the
invention, or ejecting a blanked and formed shell from
the blanking and forming die station onto a fluid conveyor
device extending between the blanking and forming die station
and curling die station.
Another aspect of the present invention
provides a pneumatic transfer system in combination with
a press including a reciprocating slide and a die
station, which has a pair of cooperating tools
Mobil
therein. One of the tools is connected to the no-
ciprocatlng slide for reciprocative movement relative
to the other tool element. This pneumatic transfer
system comprises a fluid conveyor track leading -to
the die station and a guide track leading away from
the die station. Connected to the reciprocating
slide to reciprocate therewith are a first wall
member having a hole therein disposed between the
fluid conveyor -track and die station and a second
wall member having a hole therein disposed between
the guide track and die station. A reciprocating
mechanism is provided to reciprocate the slide
downwardly from its uppermost position to an interim-
dilate position wherein the first wall opening is
aligned with the fluid conveyor track to permit a
part to be fluid conveyed into the station, and then
to a lowermost position where the part is shaped by
the tool elements. Thereafter, -the reciprocating
mechanism moves the slide member upwardly from its
lowermost position -to a second intermediate position
wherein the second wall opening is aligned with the
guide track and a source of air is caused to emit a
pulse of air against the shaped part to eject it
through the second wall opening onto the guide track.
The reciprocating mechanism then moves the slide
upwardly to its uppermost position for subsequent
reciprocative movements.
A further aspect of the present invention is an
air transfer apparatus for moving a part from a first
die station to a second die station in a press
installation. The air transfer apparatus comprises a
guide track extending between the die stations and
~2~7~
having an upwardly facing surface, opposed sides
extending substantially the length of the upwardly
facing surface, end a downwardly facing surface above
the upwardly facing surface and extending sub Stan-
tidally the length thereof. The facing surfaces and
opposed sides generally define there between an
elongated space extending between the die stations.
A hollow tube member is disposed in the guide track
and has a diameter much smaller than the transverse
distance between the opposed sides, and has a plural-
fly of openings therein to provide fluid communique-
lion between the hollow tube and the elongated space.
The openings are shaped to provide air flow velocity
components in the elongated space directed toward the
second die station when a flow of air is supplied to
the hollow tube by a source of air flow connected
thereto.
It is an object of the present invention to
provide A shell press for making shells for beverage
cans and the like having a blanking and forming die
station and a curling die station operated by a
common slide assembly, and a fluid conveying track
extending between the die stations for conveying an
uncurled shell from the blanking and forming die
station to the curling die station.
Another object of the present invention is to
provide an air transfer system which in part utilizes
a hollow tube having a plurality of openings therein
for air conveying a shell from a blanking and forming
station to a curling station.
A further object of the present invention is to
provide a pneumatic system for air conveying a part
~2%6~
to a die station and for electing the part -therefrom
with a pulse of air.
Figure lo is a partially broken-away and par-
tidally sectioned front elevation Al view of the
blanking and forming die station area of a shell
press incorporating the present invention;
Figure lo is an extension of the right hand side
of the shell press of Figure lo illustrating an air
transfer apparatus extending between a blanking and
forming die station and a curling die station incur-
prorating a pneumatic transfer system;
Figure 2 is an enlarged, fragmentary, sectional
view of a blanking and forming die station illustrate
in a blanked and formed shell ready for ejection
therefrom;
Figure 3 is a top plan view of a portion of an
air transfer apparatus;
Figure 4 is a cross-sectional view of Figure 3
taken along line 4-4 and viewed in the direction of
the arrows;
Figure 5 is a cross-sectional view of Figure 3
taken along line 5-5 viewed in the direction of the
arrows and illustrates the position of an uncurled
shell being conveyed;
Figure 6 is an enlarged, fragmentary, sectional
view of the air transfer apparatus;
Figure 7 is a cross-sectional view of Figure 6
taken along line 7-7 and viewed in the direction of
the arrows;
Figure 8 is a sectional view of the curling die
station depicting an uncurled shell in a stationary
76~
position out owe the die station and a curled shell
being ejected from the die station;
Figure 9 is a view similar to Figure 8 with the
uncurled shell entering the curling die station;
Figure 10 is similar to Figure 9 illustrating
the shell being curled by the die station; and
Figure 11 is similar to Figure lo illustrating a
queried shell in a position for ejec-tment from the
curling die station.
Referring now to Figs. lo and lo the relevant
portion of shell press 12 is shown comprising blank-
in and forming die station 14, air conveyor assembly
16, and curling die station 18. Not shown is a strip
stock feeder which feeds strip stock 20 to shell
press 12 and a scrap cutter for collecting -the
skeleton of strop stock 20.
Continuing to refer to Figs. lo and lo, blanking
and forming die station 14 comprises stationary
bolster 22 secured to a press bed (not shown) and
cutting die retainer assembly 24 secured on the upper
surface thereof. Lower forming die 26, the cross
section of which is circular in a plain parallel to
tin line 28, is securely mounted within cutting die
retainer assumably 24~ Bolster 22 and cutting die
retainer assembly 24 are rigidly connected to the
shell press frame (not shown). vower forming die 26
also includes an annular bead portion on, which forms
a correspondingly shaped bead portion 32 in shell 66.
Double action slide assembly 35 comprises
blanking slide 36 slid ably received on shell press
posts Into shown) and worming slide 38 slid ably
guided by blanking slide 36. Slides 36, 38 are
12;~
driven by connecting rods and a crankshaft operated
by an electric motor (not shown) similar to that
shown in US Patent 3,902,347. Securely mounted to
blanking slide 36 is housing assembly 40, which is
slid ably disposed with respect to spindle 42 and
which retains punch 44 for slid able movement relative
thereto. Air pressure from air passage 46 yield ably
and continuously urges punch 44 downwardly towards
annular cutting die 48 in cutting die retainer
assembly 24.
Upper forming die 50 is rigidly connected to
spindle 42 by retaining rod 52, which is threadedly
secured at its lower end to forming die 50 and held
against spindle 42 at its upper end by nut 54.
Spindle 42 is secured to top plate 56, which is
connected to forming slide 38. A dowel 58 prevents
rotation between forming die 38 and spindle 42, and
forming die 50 has an annular bead portion 60 about
its periphery.
Referring now to Figs. lay lo, and 2, ejector
mechanism 62 has ejector bar 64 in a ready position
to eject blanked and formed shell 66 from blanking
and forming die station 14. When blanked and formed
shell 66 is positioned as indicated in Figure 2
during the shell press cycle, ejector bar 64 is
positively moved by ejector mechanism 62 to a post-
lion wherein it contacts shell 66 and thereafter is
positively, rapidly accelerated to eject shell 66
from die station 14 upwardly along incline 68 to air
conveyor assembly 16.
Referring to Ergs lay lo 3 and 7, air conveyor
assembly 16 comprises elongated guide track 70,
76~
hollow tube 72 extending -the length of guide track
70~ shaped openings 74 disposed in hollow tube 72,
and a source of high pressure air flow (not shown)
connected to hollow tube 72 by a suitable connector
76. although the disclosure is concerned with the
conveyance and subsequent shaping of a single shell
66, the present invention fully contemplates a
plurality of shells 66 being blanked and formed for
conveyance along at least two guide tracks 70 post-
toned one on top of the other to a plurality of
curling die stations 18.
In Figs. lay lo, 5, a support plate 78 extends
between blanking and forming die station 14 and
curling die station 18 and has incline 68 secured to
its left hand end portion by screws 80 received
through incline holes 82 and threaded holes 84 in
support plate 78. Incline 68 has a narrow neck
portion 86 fig. 3) for ease of installation only,
and upwardly facing surface 88 (jig. 4) of incline I
is formed by a tapering end section of guide track
70, which is secured -to support plate 78 by screws 90
received through guide track holes 92 and threaded
holes (not shown) in support plate 78.
Viewing Figs 3 and I guide track 70 has a
lower surface 94 with a groove 96 centrally disposed
longitudinally therein. Secured within the length of
groove 96 is hollow tube 72 having one end 100 closed
and the other end 102 (Fig. lo) connected to connect
ion 76 to supply high pressure air flow -through the
length of hollow tube 72. Important to the invention
is the very small diameter of hollow tube 72 in
relation to the width of lower surface 94 and the
~L22~
13
diameter of a shell 66. This allows hollow tube 72
to be easily installed in narrow spaces, for example,
between guide tracks positioned one upon the other to
provide fluid conveyance of shells from one area to a
second area within shell press 12. Hollow tube 72
has a plurality of shaped openings 74 uniquely
stamped therein. Each stamped portion 104 (Figs. 6,
7) of hollow tube 72 has a concave surface 106 and a
convex surface 108, which faces generally inwardly of
hollow tube 72. Consequently, when a supply of high
pressure air is provided in hollow tube 72, a flow or
high pressure air is discharged through each of the
shaped openings 74 providing generally perpendicular
and generally parallel velocity components relative
to lower surface 94, whereby a shell 66 may be lifted
upwardly and moved along lower surface 94 in the
direction of the parallel velocity components. To
confine shells 66, opposite side walls 110 (Fig. 5)
up stand from lower surface 94 and each side wall 110
has an overhanging extension 112 inwardly disposed
over lower surface 94. Side walls 110 are spaced
apart a distance slightly greater than the diameter
of a shell 66, and remote ends 114 of overhanging
extensions 112 are spaced apart a distance slightly
less than -the diameter of shell 66. Side walls 110
and overhanging extensions 112 permit a shell 66 to
be fluid conveyed over lower surface 94 in a manner
depicted in Fig. 5. Note that shell 66 is lifted
above lower surface 94 by the perpendicular velocity
components exiting shaped openings 74 and moved along
lower surface 94 by the parallel velocity components
exiting shaped openings 74.
I
Referring to Figs. lo, 8 and 11, curling die
station 18 comprises curling die retainer asser,~ly
116, lower curling die 118, lift out device 120, upper
curling die 122, and sleeve 124. Curling die retain-
or assembly 116 is securely mounted to stationary
bolster 22 and has lower curling die 118 and lift out
device 120 included therein.
Lift out device 120 comprises annular lift out
element 126 slid ably received within curling die
retainer assembly 116 and about lower curling die
118. Lift out element 126 is also receivable within
circular groove 130 in bolster 22, however, lift out
element 126 is biased upwardly by annular spring 128
disposed within groove 130. Lift out arm 132 is
slid ably received within opening 136, which has a
narrow upper portion 138 and a wider lower portion
140. Lift out arm 132 has cylindrical seat 134
secured to its upper end, and a small piston 142
secured to its lower end in lower portion 140 of
opening 1360 Lit out arm 132 is biased upwardly by
spring 144, which is disposed below piston 142 and in
opening lower portion 140 and cylindrical bore 146 in
bolster 22.
Slid ably disposed in upper curling die 122 is
piston 148 which has a narrow mid portion 150 slid ably
received within opening 152, upper portion 154
slid ably received within opening 156, and lower
portion 158 slid ably received within opening 160.
Two O-ring seals 162, 164 are disposed in respective
grooves 166, 168 in upper curling die 122 and piston
upper portion 154, respectively. A source (not shown)
of air provides air under pressure to space 170
Lo
defined by opening 156 in upper curling die 122 and
slide opening 172 in which upper curling die 122 is
slid ably received.
Sleeve 124 has opening 174 disposed in its side
and vertically aligned with guide track lower surface
94, and an angled opening 176 disposed in its sod
just slightly below opening 174. Opening 174 has
vertical and lateral dimensions sufficient to allow a
blanked and formed shell 66 to pass there through into
curling die station 18. Conduit 178 is disposed in
support 180 of curling die retainer assembly 116 and
has a source snot shown) of air flow connected to it
opposite end. limit switch (not shown) in curling
die station 18 causes the source of air connected to
the opposite end of conduit 178 to emit a pulse of
air flow through conduit 178 when angled opening 176
becomes aligned therewith (Fig. 8). Disposed in
sleeve 124 on its side opposite opening 174 and just
slightly below opening 174 is opening 182 which has
vertical and lateral dimensions sufficient for the
ejection of a curled shell 188 there through.
Guide track 70 is connected to support 180,
which has a hole 184 disposed -therein to allow a
conveyed blanked and formed shell 66 to pass there-
through into curling die station 18. Support 180 has
a second hole 186 disposed therein to allow an
ejected curled shell 188 -to pass there through for
further conveyance by air conveyor assembly 16 or
other suitable conveying means.
Fig. 9 illustrates a blanked and formed shell 66
being received within curling die station 18 and it
should be noted that the upper surface 190 of seat
Lo do
16
134 is substantially coplanar with guide track lower
surface 94 and support hole 184 so that shell 66 may
be smoothly conveyed within curling die station 18.
Likewise, Fig. 8 illustrates a curled shell 188 being
ejected from curling die station 18, and it should be
noted that upper surface 190 is substantially co-
planar with support hole 186 and lower surface 94 of
air conveyor assembly 16 or other suitable conveying
means.
Upon receiving a portion of strip stock 20,
blanking and forming die station 14 blanks and forms
a shell 66 and ejector mechanism 62 ejects shell 66
onto guide track lower surface 94 of air conveyor
assembly 16. Blanked and formed shell 66 is then
conveyed from blanking and forming die station 14 to
curling die station 18 by the air jets having per pen-
declare and parallel velocity components directed
through shaped openings 74 of hollow tube 72. Fig. 5
illustrates the position of shell 66 in air conveyor
assembly 16 during transport and it may be seen that
shell 66 has been lifted by the perpendicular veillike-
fly components so that shell bead portion 32 is in
contact with overhanging extension 112 to prevent
shell 66 from being thrown from lower surface 94, and
the parallel velocity components convey shell 66 over
lower surface 94 to curling die station 18.
Fig. 8 illustrates curling die station 18 when
the crankshaft snot shown) of shell press 12 is at
about I of crankshaft rotation. Consequently,
blanked and formed shell 66 is shown in its position
relative to curling die station 18 at about I
crankshaft rotation, and the previous shell is shown
as curled shell 188.
Beginning at approximately I crankshaft rota-
lion, blanked and formed shell 66 is positioned as
illustrated in Fig. 8 in abutment with sleeve 124.
As the crankshaft continues to rotate, blanking slide
36 is moved downwardly and at approximately 67~
crankshaft rotation (Fig. 93 sleeve 124 has moved
downwardly to align sleeve opening 174 with support
hole 184 to permit shell 66 to be fluidly conveyed
through hole 184, opening 174, and into curling die
station 18 so that shell 66 is centrally positioned
on upper surface 190 of seat 134. Throughout this
evolution, space 170 has a supply of air therein at a
predetermined pressure to bias piston 148 downwardly
as depicted in Fig. 8.
Fig. 10 illustrates curling die station 18 at
approximately 180~ crankshaft rotation. During
crankshaft rotation from about 67~ to about 180~,
piston lower portion 158 contacts the upper surface
of shell 66 to firmly hold it in place during the
curling operation. As blanking slide 36 continues to
move downwardly, lower curling die 118 is forced
downwardly against the spring forces of springs 128,
144. After springs 128~ 144 have been fully come
pressed, upper curling die 122 is forced downwardly
by blanking slide 36 under a force that is greater
than the force applied against piston 148 by the air
in space 170. The greater force supplied by blanking
slide 36 to upper curling die 122 causes it to curl
shell bead portion 32 against inner curling surface
192 of sleeve 124. Just shortly before this curling
I
18
operation, lift out arm 132 has fully compressed
spring 144 so that further downward movement by seat
134 is prevented. Annular lift out element 126 -then
moves downwardly a small distance against spring 128
to allow die annular bead portion 196 to fully seat
with die annular bead portion 194 to curl shell bead
portion 32 against inner curling surface 192.
As the crankshaft rotates from about 180~ to
approximately 264~, the position of curled shell 188
within curling die station 18 is as illustrated in
Fig. 11. As the crankshaft begins to rotate past
approximately 180~, blanking slide 36 begins to move
upwardly to a position where the force exerted by it
on upper curling die 122 becomes less than the force
exerted against piston 148 by the air within space
170. At this particular point, and as blanking slide
36 continues to move upwardly, upper curling die 122
moves upwardly so that die annular bead portion 196
separates from curled shell 188 while piston lower
portion 158 remains forced against the upper surface
of shell 188. Upon further upward movement by
blanking slide 36, lower curling die 118 is stopped
from further upward movement while lift out element
126 and lift out arm 132 move upwardly under the
spring forces exerted by springs 128, 144, respect
lively. This causes the die annular bead portion 194
to separate from shell bead portion 32, and at this
point curled shell 188 is being firmly field by seat
134 and piston lower portion 158.
As the crankshaft approaches approximately 264~
rotation, blanking slide 36 continues to move upward-
lye to draw piston lower portion 158 away from the
19
upper surface of curled shell 188 as depicted in Fig.
11, so that curled shell 188 now rests on lift out
element 126 and upper surface 190 of seat 134 as
depicted in Fig. 11.
Referring again to Fig. 8, curled shell 188 is
being conveyed from curling die station 18 onto lower
surface 94 of air conveyor assembly 16 or other
suitable conveying means. As the crankshaft rotates
from about 264~ to about 294~, sleeve 124 moves
upwardly so that sleeve opening 182 becomes aligned
with curled shell 188 and sleeve opening 176 becomes
aligned with conduit 178. Shortly before sleeve
opening 176 aligns with conduit 178, a limit switch
Into shown) in curling die station 18 is tripped to
cause the source of air connected to the opposite end
of conduit 178 to emit a pulse of air flow through
conduit 178 and sleeve opening 176 against curled
shell 188 to eject it through sleeve opening 182 and
support hole 186 onto lower surface 94 of air convey-
or assembly 16 or other suitable conveying means.
As -the crankshaft rotates from about 294~ Jo
about 360~, curled shell 188 is fully ejected fluidly
from curling die station 18 and a second blanked and
formed shell 66 is fluidly conveyed by air conveyor
assembly 16 against sleeve 124 to be curled by
curling die station 18.
