Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~19;~
FIELD OF TEIE INVENTION
This invention relates to plastic caps having a
dependent band interconnected thereto by a p]urality of
bridges for use in indicating tamper:ing or pilfering
with the container contents. The plastic cap is
provided with drive devices which drive the band with
the cap to snap-fit the band over the bead on a
container neck as the cap is twist applied to the
container.
BACKGROUND OF THE INVENTION
There is an increasing demand for the use of
tamper indicating or pilferprooE caps on containers;
particularly in the food and beverage industry where
tampering with the contents may cause spoilage and
inconvenience to the consumer. Plastic caps are widely
used on a variety of types of containers. Many attempts
have been made at providing pilferproof features on
plastic caps to clearly indicate to the consumer whether
or not the container has been previously opened. An
example of this type of cap is disclosed in Fields,
Uni-ted States patent 3,329,295. The band with tamper
indicating feature is snap-fitted over a bead on a
threaded container neck. To prevent breakage of the
bridges which connect the band to the cap, a specially
designed capping chuck is used which grips both the cap
and the band at the same time to rotate both parts as
the band is snap-fitted over the bead of the container.
Most industries are already set up for screw~on
type cap applications; however, with the Fields type of
closure, special chucks have to be designed which
require refitting of many of the existing machines at
considerable expenseO
Another approach to applying a pilferproof cap to
a container involves a downward force to snap-fit not
only the band over the bead on the container, but also
the threads of the cap over the threads on the container
neck. This technique is disclosed in French patent,
1,536,459 to Rapeaud et al. In view of the band being
directly snap-fitted over the bead on the container
without any -twist application, the bridges which connect
the band to the cap are not overstressed so that
breakage of the bridge is avoided. However, as with
Fields, the Rapeaud et al design has the same problem in
that substantial modification in the capping machines
would be required.
French patent 1,531,775 to S.A. Albaco discloses
a pilferproof cap having a type of drive system which
ensures that the band rotates with the cap, as the band
is snap-~itted over a bead on the container. This
protects the bridges which connect the band ~o the
tearstrip of the pilferproof arrangement. The drive is
provided in the form of closely spaced teeth and notch
portions in the pilferproof band and tear part. The
teeth and notches abut during cap application to rotate
the band with the cap as it is snap-fitted over the
container bead. A similar form of drive mechanism is
disc:losed in German Offenlegungsschrift 1,955,0~17 to R.
Finke. Bridges are used to interconnect the pilferproof
band portion to the cap. To protect the bridges, teeth
extending downwardly from the cap and upwardly from the
band abut one another as the cap is applied to rotate
the band with the cap in snapping the pilferproof band
over a bead on a container neck. The difficulty with
both of these cap designs is that the drive mechanisms
are arranged so as to be close to one another or close
to the cap and band portions. This results in
arrangements which are difficult to mold by injection
molding techniques, because narrow spacings between band
and cap and the drive devices usually results in "flash"
problems where the inj~cted plastic seeps around parts
of the mold to undesirably interconnect portions over
the narrow spaces.
The pilferproof cap design, according to this
invention, provides considerable spacing between all
components of band and cap to facilitate injection
molding by improved bridge designs for interconnecting
the band to cap.
SUMMARY OF THE INVENTION
. . _ . _ . .
1~2~
~ screw-on plastic cap with tamper indicatiny
provision comprises a cap with depending band having an
internal shoulder adapted for snap-fit engagement with a
bead on a threaded container neck. A plurality of means
connec-t the band to the cap. The connec-ting means may
be in the form of a plurality of bridges which readily
break when the cap is unscrewed from the container neck
with the band shoulder enyaged with a bead on the
threaded container neck. A plurality of cooperat:ing
drive devices are associated with the cap and band to
drive the band with the cap as it is snap-fitted over
the bead on the threaded container neck, when the cap is
screw applied to the container. Each of the drive
devices comprises cooperating abutments on the cap and
band which are normally disengaged. The abutments are
spaced apart with each abutrnent associated with the cap
having its lower portions spaced above the upper portion
of the abutment associated with the band and the
abutments are all spaced from the respective hridges.
The bridges are sufficiently weak to readily flex as the
band is applied over the bead to allow the band to move
upwardly towards the cap to engage the abutments to
drive the band with the cap to ensure the integrity of
the bridges. The arrangement is such that sufficient
spacing is provided between the cap and band in between
cooperating abutments of the drive devices to facilitate
molding.
The bridges for interconnecting the band -to the
cap may be very thin and fragile so as to be considered
as filaments. The filaments are sufficiently weak to
readily sever upon unthreading the cap from the
container to indicate that the container has been
pilfered. The filaments are preferably obliquely
oriented relative to the cap longitudinal axis to flex
and readily permit the band to move towards the cap, as
the band is snap-fitted over the bead on -the threaded
container neck. This movement engages the drive devices
to drive the band with the cap to ensure the integrity
of the filaments.
To encourage movement of the cooperating
abutments of the drive devices towards one another as
the band is moved upwardly towaxds the cap, the bridges
may all be sloped upwardly in the direction of twis-t
application of the cap onto the container. The bridges
readily flex as the band is snap-fitted over the bead on
the container to allow movement of the band towards the
cap and cooperate with the circumferential shifting of
the band relative to the cap in moving the abutments
towards one another so that they can readily engage and
drive the band with the cap.
BRIEF DESCRIPTION OF THE DRAWINGS
. _
Preferred embodiments of the invention are shown
in the drawings wherein:
Figure 1 is a perspective view of a pilferproof
cap embodied by the invention about to be applied on the
threaded container neck having the bead portion over
which the pilferproof band is snap-fitted;
Figure 2 is a section of the cap of Figure 1 with
portions removed to show the interconnecting bridges and
the drives for rotating the band with the cap to protect
the bridges as the band is snap~fitted over the bead on
the container;
Figure 3 is a side elevation of the bridges and
drive elements of Figure 2;
Figure 4 is a section of a threaded container
neck with -the cap of Figure 1 about to be screw threaded
thereonto;
Figure 5 shows the pilferproof band portion
expanding circumferen-tially and being snap-fitted over
3Q the bead on the container;
Figure 6 shows the flexing of the bridges to
engage the drives to rotate the band with the cap;
Figure 7 shows the pilferproof band snap-fitted
over the bead of the container;
Figure 8 shows the unthreading of the cap from
the contai.ner and the stretching of the bridges;
. 5
Figure 9 shows the band as engaged with the bead
on the container and the elongation of the bridges while
unthreadlng the cap from the container;
Figure 10 shows the bridge broken with the drives
disen~aged in unthreading the cap from the container;
Figure 11 shows an additional feature of the
invention for housing the drive device components
carried with the cap;
Figure 12 shows an alternative embodiment of the
invention for the drive devices; and
Figure 13 is a side view of the alternative drive
device shown in Figure 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Plastic caps for use in the container closure
field are normally formed by injection molding
techni~ues which are well understood by those ski.lled in
the art. The cap, according to this invention, may be
formed from various plastic materials which are commonly
used in the injection molding of plastic caps.
Preferred materials are polyethylene, polypropylene, and
copolymers of polyethylene and polypropylene. The caps
may have integrally formed on their undersides, fins or
the like for purposes of sealing with the container rim
and neck portions, or the cap may be adap-ted for use
with a liner sealer.
Re~erring to Figure 1, the cap 10, according to a
preferred embodiment of the invention, comprises a cap
body portion 12 with depending band 14 which are
concentric about cap longitudinal axis 15. The band is
interconnected to the cap by a plurali-ty of bridges 16
The bridges are circumferentially spaced apart and
according to this embodiment, the bridges are
approximately evenly spaced apart. The cap 10 is
adapted for twist application to a threaded container
neck portion generally designated 1~. Threads 20 are
provided on the exterior of the container neck. Beneath
the threads is a bead 22 integrally provided on the
bottle neck, where the band 14 is adapted to be
snap-fitted over the bead 22 as -the cap is twist applied
to the container. Normally, the cap seals the container
by engagement with the container rim 24 and optionally
with proximate interior and exterior surfaces of the
contalner neck. To ensure integrity oE the bridges 16
as tlle band 14 is snap-fitted over the bead 22 duriny
twist application of the cap 10, a plurality of drive
devices generally designated 26 are provided which drive
the band 14 with the cap to prevent breakage of the
bridges 16 as the band is snap-fitted over the bead 22.
Turning to Figure 2, the cap body 12 comprises a
side wall portion 28 and a top wall portion 30. On the
underside of the top wall 30, an annular fin 32 is
provided which is adapted to engage the container rim 24
to seal the container when the cap is firmly seated on
the container neck. On the interior of the side wall
28, a threaded arrangement 34 is provided which is
adapted to engage and cooperate with the threads 20 of
the bottle neck so that the cap may be screw applied to
the bottle in accordance with standard techniques.
The bottom portion 36 of the cap side wall 28 has
a plurality of depending projections 38 extending
downwardly therefrom and which form a component of the
drive device 26. The other component of the drive
device 26 is provided by the recess 40 in the band 14.
The recess is of a width greater than the width of the
cap projection 38. The band, as more clearly shown in
Figure 2, is connected to the lower portion 36 of the
cap by the bridge 16 which slopes upwardly in the
direction of cap twist application designated by arrow
42.
Details of the drive device 26 is shown more
clearly in Figure 3 where the recess 40 provides a
vertical face 44 and projection 38 provides a vertical
face 46. Offset ~aces 44 and 46, as they oppose one
another, constitute the cooperating abutments of the
drive device. The abutments or the operative portions
of abutments 44 and 46 are vertically spaced apart, i.e.
offset, such that the lower portion of face 46 is
slightly above or approximately in -the same plane as the
upper portion of face 44. As can be seen, they are
normal]y disengaged and become engaged by movement of
the band 14 towards the cap lower portion 36. The band
movement occurs during twlst application of the cap to
the container as the band internal shoulder 48 enyages
the bead 22 on the container neck 18.
The commencement of application of the cap 10 to
the container neck 18 is shown in Figure 4, where the
threads 34 on the interior surface of side wall 23
engage the threads 20 on t.he container neck 18. Another
common form of sealer is the liner 5B which is located
beneath the top wall 30 of the cap. It is squeezed
against the rim 24 of the container neck 18 to seal the
container in the normal manner. With twist application,
the internal shoulder 48 on the band 14 engages the lead
in portion 50 on the bead 22. The internal shoulder 48
is rounded at 52 so as to cammingly engage the sloped
surface 50. This assists in expanding circumferentially
the band 14 as the shoulder 48 is snapped over the bead
22. Also as more clearly shown in Figure 4, the bridge
16 is the same width as the upper portion 55 of the band
14; however, it tapers inwardly to a thinner portion at
56 where it joins the lower region 36 of the cap 10.
This is to ensure that when the bridges are broken, the
severance is made at the juncture 56 with the cap.
By continued screw threading of the cap onto the
container, the band 14 continues to spread outwardly as
the internal shoulder 48 is pushed further down the bead
22. Considerable resistance is encountered in pushing
the internal shoulder 48 of the band 14 downwardly over
the bead 22. In the absence of drive devices, the band
shoulder in engaging the bead would lag behind the cap
body 12 and due to the weakness of the bridges 16, they
would break thus spoiling the pilferproof feature of the
cap. To protect the bridges 16, the drive devices 26
are actuated by flexing of the bridges 16 to allow the
band 14 to move towards the cap l.ower portion 36 to
engage the abutment faces 44 and 46. With the faces
engaged, the band 14 is driven with the cap in the
~9~ g~
direction of arrows 42 to ensure that the bridges 16 are
not overstressed or stretched to the point of breaking.
It is apparent that the physical characteristics oE the
bridges cooperate with the drives, hecause -the bridges
have to be sufficiently weak to permit engagement of the
drives. In turn, upon engagement of the drives, the
bridges are protected from breakage.
To facilitate injection molding of the cap, the
arrangement according to this invention provides
considerable spacing bet~een the band 14 and the cap 12;
and between the operative faces 44, 46 of the drive
device 26. The bridges are designed so as to be
suf:Eiciently flexible to allow movement of the band 14
towards the cap as the shoulder 48 of the band engages
and is pushed over bead 22 of the container. As shown
in Figure 6, the bridges 16 flex principally at their
junctures 56 with the cap bottom portion 36 and at 57
with the band upper portion 60. The bridge 16 in
essence collapses which allows the projection 38 to move
into the recess 40. Due to the upward slope of the
bridge 16 relative to the direction of application, as
the bridge 16 collapses the natural movement for the
band 14 is in a direction opposite to arrow 42. This
direction of movement enhances the movement of the
operative drive faces 44 and 46 towards each other.
Such flexing of the bridge 16 cooperates with the
natural tendency for the band 14 to lag behind the cap
42 as it first engages the bead 22 of the container.
Thus there is a natural flexing in the bridge 16 as the
drive faces 44, 46 move towards one another and become
engaged to commence driving the band 14 with the cap 12
to ensure that the bridges 16 are not overstressed and
broken.
The bridges may have a variety of shapes to
provide for the necessary flexing thereof. As per the
embodiment illustrated, the bridges are in the form of
thin members which could be considered as filaments to
suggest the weak fragile aspect of the bridges 16.
With the px~eferred arrangement of -the th.in
bridges or filaments 16, as shown in Figure 6, they
collapse between the upper portlon of the band 14 ancl
the lower portion 36 of the cap 12 which is also shown
in the section of Figure 5. To prevent cxushing of the
thin filaments 16 between the band and cap, -the
projection 3~ is o:E a height greater than the depth of
recess 40. The lower portion 62 of the projection 38
bottoms out on base portion 64 of the recess 40. The
difference in height between the projection 38 and the
recess 40 may be selected to be equal to at least the
width of the filament 16 -to preclude crushing of the
filament between the cap and band.
With continued twist application of the cap to
the container, the band 14 is forced over the bead 22 by
either the projections bottoming out on the recesses or
some other contact between the band and cap which exerts
the downward component of force for snapping the band
over the bead 22. As more clearly shown in Figure 7,
continued twist application of the cap 12 has snapped
the band 14 over the bead 22. The internal shoulder 28
has a ledge 66 which abuts the underside 68 of the bead
22 to form a secure engagement of the band 14 with the
bead 22. The internal portion of the band 14 above the
shoulder 48 and which is designated 70 in Figure 7, may
have an internal diameter slightly less than the
external diameter of the bead 22 so that the band
contacts the bead after the shoulder 48 is snapped past
the bead 2~. Depending upon tolerances there may or ma~
not be sufficient frictional engagement between the
interior surface of the band 14 and the bead 22 which
may allow the band to move slightly downwardly after the
band is snap fitted over the shoulder 2~.
When it is desired to open the container as
demonstrated in Figure 8, the cap is rotated in the
direction of arrow 72. The cap has a first position
designated at 12 and a second position as shown in dot
at 12a. The bridge 16 is extended from the position
shown at 16 to the dotted position at 16a. While the
cap is unthre~ded in the direction of arrow 7~, the
bridye 16 contlnues to be distended or stretched as the
ledge 66 on -the shoulder 48 of the band 14 engaqes the
underside 68 of bead 22. The snug contact be-tween the
band interior portion 70 and the bead 22 maintains the
inter]ock between faces 66 and 68 to ensure that the
band will not snap pas-t bead 22. Thus the bridges 16
continue to be stretched as the cap 12 is unthreaded in
the direction of arrow 72. With continued rotation of
the cap as shown in Figure 10, the stretched bridges 16
break at a thinner portion 56 to leave a thin nub
portion 74 on the lower portion 36 of the cap 12.
During this removal of the cap from the container, it
can be seen that the projection 38 is clear of the
recess 40 so that there is no interference of the drive
device with the band in remova] of the cap.
Depending upon the end use of the cap, as can be
appreciated from Figure 10, the projections 38 remain on
the underside of the cap and may be considered unsightly
or uncomfortable for the user in grasping the cap.
Alternative arrangements for the drive device are shown
in Figures 11, 12 and 13. Figure 11 shows the cap 12
having on its lower portion 36 a depending skirt 80
which envelopes the projections 38 so that they are not
exposed. The band 14 has its upper portion 60 within
the skirt 80 where the bridges 16 flex, so that the
operative abutment drive faces 44 and 46 may engage.
Another approach is to p~ovide the projections of
the drive devices on the band. Referring to Figure 12,
the band 14 has an upstanding projection 82 extending
upwardly from it upper portion 84. The bridge 16
interconnects the band 14 to th cap 12 at the lower
portion 36 of the cap 12. A recess 86 is provided in
the cap whereby the operative faces of the drive device
is provided by abutments 88 on projection 82 and face
portion 90 of recess 86. This relationship is shown
more clearly in Figure 13, where it can be see~ that
operative face portion 88 of the projection 82 will
engage face 90 of recess 86 when the cap is rotated in
the direction of the arrow 92. ~s with the other
embodiments, the bridge 16 will flex and allow the band
to approach the cap as demonstrated by arrows 94 to
engage the offset operative faces of the drive devices.
This ensures integrity of the bridges 16 as the band l~
has its shoulder portion 48 snap fitted over the
container bead.
It is apparent from the preferred embodiments of
the invention that considerable spaciny is provided
between the band upper portion and cap underside and
between the drive components. Thus injection molding of
the cap is facilitated where flashing is minimized
because of the considerable space now provided~ This
is, of course, accomplished by the particular drive
mechanism of this invention where the operative faces
are vertically spaped apart and by way of appropriate
flexible interconnecting bridges, the operative faces
become engaged by movement of the band towards the cap
as the band begins to be snap fitted over the container
bead.
The preferred arrangement for the bridges is that
all the bridges are sloped upwardly relative to the
direction of application of the cap to provide
parallelogram-type linkages. The bridges or filaments
flex at their junctures with the band and cap to allow a
circumferential shift of the band relative to the cap
which cooperates with the band tending to lag behind the
cap as it is applied. This action moves the operative
faces oE the drive devices towards one another, so that
they engage before the bridges are overstressed.
Although single bridges are shown in the preferred
embodiment of the invention, it is appreciated that
other bridge arrangements are possible which are
inclined in some other manner relative to the
longitudinal axis of the cap. This inclination of the
bridges provides ready flexing or the bridges in
allowing movement of the hand towards the cap.
The cap, according to this invention, is
particularly suited for application to large mouth jars,
~:~9~
12
such as ~ood jars and the like. The positive drives for
protectiny the bridges ensure that the band, with larger
lnternal shoulder, is snapped over the bead on -the jar.
This is beneficial when the jars are of glass because of
the larger variation in dimensions of the bead diameter
on the larger glass jars. In addition, the positive
form of drives are particularly suited for high speed
twist cap application, for example, twist applications
at speeds in excess of 240 rpm.
~lthough various preferred embodiments of the
invention have been described herein in detail, it will
be understood by those skilled in the art that
variations may be made thereto without departing from
the spirit of the invention or the scope of the appended
claims.
