Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
FIELD OF INVENTION ~043~62
.
This inven~ion relates to the manufacture of closure caps,
particularly, closure caps with lugs, undercuts and intermit-tent
or interrupted threads.
BACKGROUND OF T~E INVENTION
Plastic closure caps can be manufactured in different
ways, with continuous threads, with a partial or intermittent
thread, more often called an interrupted thread, or with spaced
hold-down lugs, used in, for example, child resistant safety
vials, which may each be used in conjunction with liner
retension segments, disposed on the inner surface of the skirt
of the closure cap adjacent the undersurface of the cap. The
interrupted thread may comprise screw threading, interrupted by
a plurality of axially extending gaps on the interior wall of
the skirt and the lugs may be circumferentially spaced from one
another on the inner wall of the skirt of the cap.
~ lthough specialized systems have been proposed for the
manufacture of closure caps having interrupted threads or lugs,
because of the variance in the material used in the manufacture
of such closure caps and the shape and size of the relevant
component parts thereof, such systems have not been satisfactory.
One such system, manufactured by D.M.E. Corporation,
includes what is usually called a collapsible core, comprising
axially extending segments~ the outer periphery of each
comprising an arc of a circle, held together in assembled
circular closure cap manufacturing relation, by a centre pin
disposed on the longitudinal central axis of the core, and an
outer ring. After the manufacture of the closure cap, the
centre pin is moved out of the centre and the ring surrounding
3~162
the segments, collapses the segments radially inwardly towards
the axis, some collapsing further radially inwardly than others,
to permit each segment to clear the undercuts of the thread and
permit ejection of each closure cap without interference.
Subsequently, the segments are repositioned by the longitudinal
pin and ring and the cycle is repeated, However, this core is
very expensive and its construction inherently limits the depth,
or the thickness, of the thread finish to be manufactured on
the skirt of the closure cap, particularly, closure caps
smaller than 28 mm. Furthermore, if one of the segments breaks
away, the entire core must be replaced thereby increasing
substantially the maintenance costs of the system~
It is therefore~ an object of this invention to provide
an improved system and components therefor, used in manufacturing
closure caps having interrupted threads or hold-down lugs, with
or without liner retension segments, having improved
characteristics, thereby minimizing initial cost and
substantially reducing maintenance costs.
It is a further object of this invention to provide
such a system having fewer components.
It is a further object of this invention to provide a
more efficient system and components thereof, thereby
maximizing product output.
It is still a further object of this invention to
provide a system useful in manufacturing closure caps of a size
less than 28 mmO
It is still a further object of this invention to
provide a system suitable for the manufacture of deep closure
caps.
--2--
)4;~
It is still a further object of this invention to
provide a system, including a core whereby any brolcen parts of
ths core can be individually replaced.
Still other objects and advantages of this invention
will be realized by those skilled in the art from the following
summary of the invention and more detailed description of
preferred embodiments thereofO
SUMMARY OF THE I~VE~TIO~
According to one important aspect of the invention, a
system and components therefor, used in the manufacture of
closure caps with interrupted threads or hold-down lugs with
or without liner retension segments, each closure cap having a
top, a depending skirt and a plurality of interrupted threads,
or hold-down lugs, spaced one from the other by axially
extending gaps, is provided including a core for such system,
each core comprising (a) a top forming portion at one end
thereofg lb) a plurality of skirt forming portions disposed
alternately in the outer periphery of the core, with generally
longitudinally disposed channels ln the core, each channel
extending from at least a point intermediate the length of the
core to the top forming portion, having its bed sloped
radially inwardly towards the central longitudinal a~is of the
core, from at least a point intermediate the length of the
channel to the top forming portion.
According to another aspect of the invention, riser
segments are secured for slidable movement relative to the
core, within each channel on the sloped bed thereof from a
position substantially within the channel and having one end
thereof proximate the top forming portion of the core to a
--3--
: - ~
L3all~Z
position on khe side of the top forming portion remote the
other end of the core.
According to another aspect of the invention, each
riser segment is of suhstantially the same radial thickness as
the corresponding depth of the channel in which it is seated
when the one end of the riser, is proximate the top forming
portion of the core.
According to another aspect of the invention, when each
riser is substantially within the channel having one end
proximate the top forming portion of the core, such end of the
riser is positioned to co-act with the top forming portion of
the core and a radially outer peripheral portion of the riser
is provided comprising a skirt forming portion of the riser
of substantially the same length as the skirt forming portion
of the core.
~ccording to another aspect of the invention, securing
means comprising an interrupted thread or lug forming portion
is disposed on the skirt forming portion of each riser with or
without a liner retension forming portion.
According to another aspect of the invention, means are
provided for securing said riser segments for relative
movement with respect to the core within said channels.
According to another aspect of the invention, the
system includes means to limit the relative movement of the
risers with respect to the core from a position where one end
of the riser is positioned to co-act with the top forming
portion of the core ko a position where such end of the riser
is moved to a position on the side of the top forming portion
of the core remote theoother end of the core.
: ~ ~43~6;~
According to another aspect of the invention, the system
includes means operable with the core to manufacture the
closure caps including an inlet for introducing molten
polymeric material into the system from which the closure is to
be manufactured and male and female mould portion, the female
mould portion including means to form the outer configuration
of the top of the closure cap, and the male mould portion
mounting the core including means for longitudinally separating
the male mould portion from the female mould portion from their
closure cap forming position, relative to one another and
withdrawing the core relative to the risers in the direction
away from the female mould for collapsing the risers radially
inwardly for disposing the formed closure cap out of contact
with the ri~ar segments, until the closure cap is ejected, means
for ejecting the formed closure cap and means for
reciprocating the member components for repeating the cycle.
Preferably the female mould is stationary and includes
the inlet for feeding the molten plastics material into a
cavity between the male and female mould portions when in the
closure cap forming position relative to one another and the
male mould portion moves relative to the female mould por~ion.
Preferably the operating axis of the system and thus the core
is in a horizontal plane to permit the manufactur~d closure
caps to fall downwardly by gravity clear of both mould portions,
when ejected by the ejector means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be illustrated with reference to
the following drawings, in which preferred embodiments thereof
have been illustrated.
--5--
3062
Fiqure 1 is a perspective view of a system useful in the
manufacture of closure caps with interrupted threads according
to a preferred embodiment of the invention, illustrating male
and female mould portions in withdrawn ralation after the
manufactured closure cap has been ejected and prior to the
closing of the system for repetition of the cycleO
Fiqure 2 is a partial vertical cross section, taken
along the line 2-2 of Figure 1, and looking in the direction of
the arrows when the male and female portions are in closure cap
forming relation illustrating lug forming portions on the risers
according to a second preferred embodiment of the invention.
Fiqure 3 is a similar vertical cross sectional view as
in Figure 2, except that the male mould portion has been
withdrawn in a direction away from the female mould portion.
Fiqure 4 is a similar view to Figure 3~ except the male
mould portion has been further withdrawn from the female
portion.
Fiqure 5 is a similar view to Figure 4, `except that the
female mould portion is not shown and the formed closure cap
has been ejected.
Fiqure 6 is a horiæontal section taken in various planes
in Figure 1 to illustrate the various functional parts used to
reciprocally operate the system.
Fiqure 7 is a close~up of part of Figure 2, except the
lug forming portion of the riser is an interrupted thread
forming portion as shown in Figure 1.
Figure 8 is a close-up of a part of Figure 3 except the
lug forming portion of the riser is an interrupted thread
forming portion as in Figure 1.
-6-
3~16Z
Fiqure 9 is a close-up of the portion circled in Figure
7.
Fiqure 10 is a perspective view o~ a core according
to the first preferred embodiment of the invention.
Fiqure 11 is a perspective view of the core shown in
J
Figure 10 in a withdrawn position relative to the riser segments,
the riser segments having collapsed radially inwardly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIME~TS
Referring particularly to Figure l there is shown a
moulding system 20 comprising stationary female mould portion 22
and male mould portion 24 reciprocally moveable with respect to
female mould portion 22. Female mould portion 22 comprises
top mounting plate 26 having locating ring 25 for fastening
mould portion 22 to a press (not shown), and cavity plate 28.
On the side of cavity plate 28remote top mounting plate 26
ar~, cavity 30 seen best in Figure 4, used for forming the
outer configuration of the top and skirt of the closure cap
to be formed and, inlet 120 seen best in Figures 2, 3 and 4,
for feeding the necessary molten plas~ics material into
cavity 30 for forming the closure cap.
Core 32, seen in cross-section in Figures 2, 3, 4,
and 5, in one form mounted for closure cap forming operation
in male mould portion 24 and in perspective in Figures 10
and 11 in another form, and in various modes of operation,
is used to operate in conjunction with cavity 30 to manufacture
the under side of the top, and inner side wall of the skirt
together with the interrupted thread or hold-down lu~s,
respectively, of the closure cap. To this end, core 32 has
a closure cap forming portion 34, seen best in Figure 10
--7--
1()43(i6Z
adjacent one end of core 32 having substantially planar end 36
disposed substantially perpendicular to the ~ongitudinal a~is
of core 32 for forming the underside of the top of the closure
cap and a plurality of skirt forming portions 38 disposed in
core 32, substantially perpendicular to end 36, and separated
from one another by the upper end of channels 40.
Tapering radially outwardly from the skirt forming
portions 38, is conical portion 39A e~tending to cylindrical
portion 39B, portions 39A and 39B disposing the lower portions
of channels 40. Each of channels 40 disposed in core 32 has
bed 42 sloping radially inwardly from a point intermediate
either end of core 32 and extending to end 36. Disposed and
secured in each of channels 40 for relative movement therein
are riser segments 44 being generally h-shaped and of substan-
tially the same thickness as the same depth of the channel
portion in which it seats, when the end 43 of the riser 44
is proximate end 36. Therefore, portion 46 of riser 44
adjacent end 36 and skirt forming portions 38 of core 32 are
disposed substantially perpendicular to end 36 to provide
further skirt forming portions, which taken together with
portions 38, form an annular peripheral configuration which
forms the inner wall of the skirt of the formed closure cap.
Each portion 46 also provides means for manufacturing the
securing means on the formed closure cap, which in Figures
10 and 11 comprise threaded portions 48 on portions 46 to
provide an interrupted screw threading on the interior wall of
the skirt of the closure cap and which in Figures 2-5 inclusive,
provide a notch 50 used to manufacture hold-down lugs used in,
for e~ample, child resistant safety vials. Ring 52 is secured
--8--
3~;Z
by pin 54 to core 32 to maintain riser segments 44 within
channels 40 at all times. At the end of riser segments 44
opposite end 43 are stop or detente flanges 56 for the purposes
as hereinafter described.
Core 32 has at the end opposed the top forming portion
an annular flange 60, seen best in Figures 2-5, inclusive, of
greater diameter than any part of core 32. Each riser 44 is of
constant thickness between flange 56 and skirt forming portion
46 so as to be slidable within each channel 40 from a position
whereat the upper end 43,riser 46 is co-planar with top 36 of
core 32 to a position where the side of ring 58 remote end 36
is disposed adjacent the upper side 57 of flange 56, both
seen best in Figures 10 and 11.
Extending ~longitudinally within core 32 is pin 62,
saen in cross-section in Figures 2-5, and in Figures 1 and 10.
Pin 62 operates from a position shown in Figure 10, wherein
its upper end 63 is ~o-planar with top 36 to a position, seen
in Figures 1 and 5, spaced from top 36 on the side thereof
remote Flange 60.
For securing core 32 for co-operation with cavity 30,
of 2emale mould portion 22 for forming closure caps with
interrupted threacls or hold-down lugs with or without liner
retension segments, these embodiments further provide a
mounting assembly 23 which comprises male mould portion 24
excluding core 32 and associated components thereof, for
example~ risers 44, ring 58 and pin 62, including prehardened
stripper face plate 64 having stepped portions 64A, 64B and
64C extending to a central aperture 66, seen best in Figure
7, through which core 32 projects, steps 64B and 64C
--9--
~43(~6Z
separated by wall 122 being sloped radially outwardly, looking
towards flange 60, for the purposes hereinafter described.
Plate 64 is secured by bolts 68 (seen in Figure 2) to
stripper plate riser holder 70 and by bolts 72 (Seen in Figure
6) through stripper plate riser holder 70, to riser retainer
plate 7~. Stripper plate riser hololer 70 is in turn
secured to core plate 76 by bolt 78, having head 79, (seen in
Figures 1 and 6) secured to core plate 76 and projecting
through slot 80 in stripper plate riser holder 70, for
movement in slot 80 in stripper plate riser holder 70 of bolt
78 from a position whereat head 79, abuts bottom 82 of slot 80
to a position spaced from it, closer female mould portion 22.
Flanges 60 of core 32 seat in recess 61, in core plate 76 for
locking core 32 in relation to core plate 76. It is of course
understood that each of core plate 76, riser retainer plate
74, stripper plate riser holder 70, have appropriately
dimensioned apertures therethrough so aligned with aperture
66 of prehardened stripper face plate 64 so as to enable core
32 to project therethrough. Additionally~ stripper plate
riser holder 70 includes an annular recess 67 adjacent its
end remote prehardened stripper face plate 64 about the
aperture therethrough for the purposes hereinafter described.
Core back plate 84 is mounted behind flange 60 of core
32 and secured to abut against core plate 76 for acting as a
detent to prevent movement of core 32 relative to core plate
76 and core back plate 84. Secured to core back plate 84 is a
pair of spacer blocks 86, seen best in Figure 6 (one of which
being shown in Figure 1 as 86A). Disposed therebetween are
ejector retension plate 88 and ejector plate 90 (seen best
--10--
in Figures 2-6 inclusive) ~ ~e3d~ ~oZone another by bolt 92
(seen in Figure 6), of lesser axial length than spacer
blocks 86. Secured behind spacer blocks 86 is a back mounting
plate 94 to which they are secured. Securing back mounting
plate 94, spacer block identified as 86A, core back plate 84,
and core plate 76, for no relative m~vement with respect to
each other, is bolt 98 passing through each of plate 94,
block 86A, plate 84 and secured into plate 76.
Return pin 97 extends from back mounting plate 94
into space 96 created between spacer blocks 86 and through
eject retension plate 88 and ejector plate 90, through core
back plate 84, core plate 76, stripper plate riser holder 70,
and may extend through riser retainer plate 74 and prehardened
stripper face plate 64 ( but in these embodiments does not as
shown in Figure 1) to the face of male mould portion, and is
adapted to reciprocate simultaneously with pin 62. Secured to
- ejeCtor retension plate 88 is ejector pin 62. Therefore, when
ejector retension plate 88 and ejector plate 90 reciprocate
wlthin cavity 96, both return pin 97 and ejector pin 62
are also reciprocated.
Securing risers 44 for no relative longitudinal movement
with respect to stripper plate riser holder 70 are flanges 56
extending into annular recess 67 of a siæe to accommodate
the thickness of flange 56, to cause flange 56 to abut riser
retainer plate 74. Therefore, each riser 44 is precluded from
longitudinal axial movement relative to both stripper plate
- rlser holder 70 and riser retainer plate 74, but is free to
move radially inwardly towards, and radially away from the
axis of core 32 for the purpose as hereinafter described.
,
3~i62
Securing male mould 24 to female mould 22 are bolts 102,
only one of which is see.n in Figure 6, each bolt having head
106, disposed in and passing through, slot 104 of greater
diameter than head 106,~disposed in core back plate 84, core
plate 76 and stripper plate riser holder 70, and restricted
aperture 107 adjacent cavity plate 28, restricted in size
from slot 104 by shoulder 108, which provides a 6eat ag~inst
which head 106 ahuts when male mould portion 29 is withdrawn
from female mould portion 22.
10A plurality of guides 110, only one of which is seen
in Figure 6, is provided at the four corners of stripper plate
riser holder 70, each of which is secured in an annular recess
in ~ore plate 76 to abut core back plate 84 to preclude
relative movement thereof, for projecting through core plate
76, stripper riser holder 70 and into female mould portion
22 through cavity plate 28 and into top mounting plate 26 by
means of a slot 112 therethrough to assist in guiding female
mould portion 22 and male portion 24 into closure cap
forming position. Further guide and alignor means have been
provided, as for example, pin 114, extending between core back
plate 84 and back mounting plate 94, on which ejector
retension plate 88 and ejector plate 90 are supported for
reciprocation in cavity 96 formed by spacer blocks 86. Two
cylinders 118, mounted above and below male portion 24~ only
one of which is shown and a third cylinder mounted on the
side of the back mounting plate 94 remote core 32 (also not
shown) have been provided for the purposes hereinafter
described.
The operation of the system 20 for the product.ion of
-12-
3~62
a clo~ure cap will now be described with reference primarily
to Figures 2 to 6 inclusive~ Figure 2 illustrate~ the male
portion 24 and female portion 22 in closure cap forming
position wherein the ends 43 of risers 44 are co-planar with
the top 36 of core 32. In this position, cavity 30 i5 filled
with polymeric material for forming the closure cap through
feed inlet 120 For dispersal of the heat generated by the
molten plastics, the system may include cooling channels 130
and 132, throuyh which water may be fed through inlets and
discharged through outlets (not shown), to remove such heat
as would be well understood by those skilled in the art.
Referring to Figure 7, when the ca*ity comprising
the space between core 32 and cavity 30 of cavity plate 28 is
filled with molten plastics matarial, the space adjacent the
back or outwardly tapered wall 122 between step 64B and 64C'
of prehardened plate 64 and adjacent wall 124 defining the
outer extent of cavity 30 adjacent step 64B are filled,
particularly shown best in Figures 7 and 9 for the purposes
hereinafter discussed.
After permitting the moulded closure cap suf~icient
time to harden sufficiently, ejection from the system is
provided as follows. With reference to Figure 6, the third
cylinder, not shown, operates on back mounting plate 94 and
withdraws it in a direction away from the female mould
portion 22. Therefore, spacer blocks 86, core back plate
84 and core plate 76 are withdrawn by virtue~of their
attachment to back mounting plate 94 by means of pin 98,
pin 110 acting as a guide in the withdrawing of such components.
In turn, bolt 80, secured to core plate 76 is also withdrawn
-13-
iL04306Z
until bolt head 78 contacts the bottom of slot 82. Since core
32 is secured by annular flange 60 to core plate 76, seen
best in Figure 2, it is also withdrawnO Sinca ring 52 is
attached to core 32 by pin 54, it too is withdrawn in a
direction away from female mould 22, from a position adjacent
or proximate prehardened face plate 64 to a position
adjacent flange 56 when bolt head 78 contacts the bottom of
slot 82. However, riser segments 44 are not so connected being
retained in recess 67 of stripper plate riser holder 70 and
therefore remain stationary in the longitudinal or axial
direction, relative to female mould portion 22, as seen in
Figure 3. The longitudinal or axial distance the core and
thus ring 52 retract relative to the riser segments 44 is the
distance the head of the bolt is spaced from the bottom 82 of
the slot in which it is adapted to reciprocate when the male
mould portion 24 and female mould portion 22 are juxtaposed
in closure cap manufacturing position shown in Figure 2.
However, because ring 52 rides along riser segments 44 from
a poeition ad~acent stripper plate 64 to a position adjacent
flange S6, equal to the longitudinal distance bolt head 82
moves, riser segments 44 are foxced radially inwardly (seen
best in Figure.ll) and clear the inner radial extent of the
interrupted threads or lugs of the formed closure cap,(seen
best ln Figure 3),
Male mould portion 24 is further withdrawn from female
portion 22 for ejection of the finished cap as followsO When
bolt head 78 abuts bottom 82 of the slot, further withdrawl
of male mould portion 24 by the third cylinder (not shown)
causes stripper plate riser holder 70 to withdraw from
-14-
'
3~iiz
female mould portion 22 seen in Figure 4. Since riser segments
44 have now collapsed radially inwardly clearing the interr-
upted threads formed in the closure cap, the back taper of wall
122 between steps 64B and 6~C seen best in Figure 9, maintains
the rim of the formed closure cap and thus the closure cap
radially spaced from each of riser segments 44 by virtue of a
pressure fit between the rim and the back taper of wall 122. As
a result, the formed cap cannot interfere with riser segments
44 and cannot become caught in the interrupted thread forming
portions of such riser segment 44, prior to ejection as shown
in Figure 4. As a result, the formed closure cap and male
mould portion are withdrawn from the female mould portion
until the head 106 of bolt 102 seats on annular shoulder 108 in
stripper riser plate holder 70. In operation, it has been
found that when the third cylinder acts to withdraw back plate
94; spacer blocks 86, core back plate 84, core plate 76, it
frequently also withdraws stxipper plate riser holder 70, and
prehardened stripper face plate 64 until bolt head 106
seats on should 108, thereby separating mould portions 22 and
24. Subsequently~ any further withdrawal of back plate 94 by
the third cylinder causes separation of core plate 76 and
stripper plate riser holder 70 until bolt head 79 seats on
bottom 82 of slot 80, thereby causing the riser segments to
collapse radially inwardly, as discussed previously. In
either case, the relative positions of the components shown
in Figure 4, is reached with no deleterious affects on either
the moulding system or the formed closure cap. The attainment
of the position shown in Figure 4, causes the cylinders 118,
secured to ejector plate 90 (only one of which is shown) to
15-
1043~6~
become activated, forcing piston 126 against back mounting plate
94 (Seen in Figures 2 and 5) thereby moving ejector plate 90
towards female mould portion 22 causing ejector pin 62, pin 97
and runner ejector pin 128 to be moved towards female mould
portion 22, pin 62 contacting the underside of the top of the
formed closure cap and exerting sufficient force thereon to
force the rim of the closure out of the back taper of wall 122,
seen in Figure 5, and thereafter extending beyond riser segments
44 to force the closure cap beyond the longitudinal or axial
0 extent of the riser segments and permit it to fall downwardly
into a suitable receptacle (not shown)~
In the manufacture of the closure cap, some of the
molten polymeric material fed through inlet 120 into cavity 30
remains in the inlet and beads at the entrance thereof, and is
known in the art as a runner. Pin 128 is provided to
reciprocate simultaneously with pin 62 to eject the runner as
is well known in the artO The above steps are then reversed to
close the male and female mould portions into closure cap
forming relation and the cycle is repeated.
It is of course, obvious that a plurality of cores 32
may be operated simultaneously, incorporating them into an
operating system discussed above, appropriately modified to
accommodate the number o~ cores de~ired, including the
provision of suitable means for acting on each core for
withdrawing the core relative to the riser segments in a
direction away from the female mould for collapsing the riser
segments radially inwardly and for longitudinally separating
the male and female mould portions, while maintaining the cap
out of contact with the collapsed risers for ejecting the
-16-
~43~
closure cap and for reciprocating the member components to
close the male and female mould portions into closure cap
forming relation so as to enable the cycle to be continuously
repeated.
As many changes can be made in the construction of
the core and the means used to operate the core without
departing from the scope of the invention, it is intended that
all matter contained herein shall be deemed to be illustrative
only of the invention and shall not be interpreted in a
limiting sense.
-17-
