Note: Descriptions are shown in the official language in which they were submitted.
CA 02503092 2005-04-18
DRINKING CUP
held Of The Invention:
The present invention relates generally to containers for packaging including
drinking
cups, and more particularly to containers and drinking cups having reinforcing
projections and valleys on its side walls.
Background Of The Invention:
It is known to sell beverages in disposable or reusable plastic drinking cups
for carry-
out sale of beverages such as soft drinks and the like. It is also generally
known to
package goods and foodstuffs in disposable or reusable plastic containers.
Generally,
such drinking cups or containers are made of rigid, injection-molded plastic.
A
problem with manufacturing these containers is that the cost of manufacturing
varies
with both the amount of material used in each container as well as the time it
takes for
one cycle of the injection molding machine to be completed. The less material
used in
a container, the thinner the container wall and the faster the injection
molding
1 S machine will be able to produce a container. The lower limit for the
amount of
material used in each container is determined by the minimum wall thickness,
below
which the container can no longer support the vertical and tangential loads
applied
during use.
It is a challenge to manufacture containers with minimal material due to the
material
requirements of the sidewall of the container. The taller the container, the
thicker the
sidewall must be to support the structure. It is difficult in manufacturing
processes to
cycle enough material to the top of the sidewall to meet mold-filling
requirements. A
sidewall having a specific thickness must meet a minimum fill ratio of height
to
diameter in order for material to flow to the top of the container. There is a
need for a
container having a design including high points and valleys. There is a need
for such a
container that allows the material to flow via the high points to the top of
the vessel
and where the valley sections reduce the weight of the vessel. There is a need
for such
a container that provides more efficient cooling and a faster cycle.
These problems are addressed by the present invention. Accordingly, it is a.n
object of
one aspect of the present invention to provide a drinking cup or other
container having
a construction that reduces the amount of material necessary to produce a
structurally
stable cup or container and that permits the requisite amount of material to
be cycled
CA 02503092 2005-04-18
to the top of the structure during manufacturing. This results in a drinking
cup that
costs less to manufacture than current cups now on the market.
Summary of the Invention:
In one aspect of the present invention, there is provided a reinforcing
profile for the
S side wall of a drinking cup or other container, that minimizes the material
used while
maximizing the structural strength of the cup or container. Specifically, this
aspect
includes a drinking cup or container, comprising: a cup body having a
generally
circular periphery, a bottom, a top rim, and a side wall extending from the
bottom to
the top rim; the side wall having inside and outside surfaces, and the side
wall
comprising a plurality of vertically-oriented, concave-shaped valleys on the
outside
surface about the periphery of the drinking cup or container; and a plurality
of
reinforcing projections on the outside surface, the reinforcing projections
defined by
respective pairs of adjacent valleys, wherein the reinforcing projections
provide
additional stiffness to the side wall.
In another aspect of the invention, there is provided a drinking cup or
container,
comprising: a cup body having a generally circular periphery, a bottom, a top
rim, and
a side wall extending from the bottom to the top rim; the side wall having
inside and
outside surfaces, and the side wall comprising a plurality of vertically-
oriented,
concave-shaped valleys on the inside surface about the periphery of the
drinking cup
or container; and a plurality of reinforcing proj ections on the inside
surface, the
reinforcing projections defined by respective pairs of adjacent valleys,
wherein the
reinforcing projections provide additional stiffness to the side wall.
In another aspect of the invention, the periphery of the drinking cup or
container body
at the top rim has a first diameter that is larger than a second diameter of
the periphery
at the bottom and the valleys have a width that decreases from the top rim to
the
bottom.
In a further aspect of the invention, the drinking cup or container comprises
a base
having a generally circular periphery, a side wall extending from the
periphery of the
base, and terminating at a lip, the side wall having a repeating segment of a
conic
cross-section on one surface of the wall.
The invention has a number of advantages and features that increase its value
as a
drinking cup or container design. As previously mentioned, the reinforcing
profile
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CA 02503092 2005-04-18
enables a construction of a drinking cup or container using less material than
previous
methods, while maintaining the structural strength and integrity of the
drinking cup.
Less material also allows faster injection mold cycling, allowing more cups to
be
produced each day, thus reducing the manufacturing cost per day.
The profile enables the cup or container to be manufactured using less
material and at
a faster rate as the reinforcing proj ections provide a channel within the
mould for
material to flow from the base of the cup to the lip. Without the channel
provided by
the reinforcing projections, material would have difficulty in flowing through
the
narrow side wall from the base to the Zip of the cup.
Placing the reinforcing profile on the inside of the cup or container has
additional
advantages. With the profile on the inside, the exterior of the cup may be
decorated by
printing with high speed offset presses. Furthermore, a customer may have a
name
etched on the interior surface of the cup mould. If the cup is formed of clear
material,
the name will show through the wall of the cup. If the customer wishes to
change the
appearance of the cup, the same mould may be used with colored material so
that the
name will not show through the side wall of the cup. The customer may then
optionally have a different name or graphic printed on the exterior. This
advantageously allows the use of the same mould for different style cups,
reducing the
cost of manufacture.
The channel profile of the present invention allows a cup or container to be
moulded
faster with a thinner sidewall by using an outer portion of the wave material
to the top
lip in a faster cycle. The channel profile also allows the moulding apparatus
to cycle
faster by giving the material a thicker pathway to the top
The channel profile of the present invention further allows half the mould to
be
utilised without reducing efficiency. An operator can change the cavity
section of the
mould to provide different wording to be printed on the cup or container
surface. This
reduces mould production cost by about fifty percent.
In one preferred embodiment of the present invention, the lip portion may be
thickened to provide additional hoop strength.
In another preferred embodiment of the present invention, the design of the
side wall
profile assists in preventing sink marks on the smooth side of the side wall.
This
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ensures the ability to provide smooth coverage if applying printing to that
surface in a
later manufacturing step.
Brief Description Of The Drawings:
The preferred embodiments of the present invention will be described with
reference
S to the accompanying drawings in which like numerals refer to the same parts
in the
several views and in which:
Fig. 1 shows a side view of a drinking cup of one preferred embodiment of the
present
invention;
Fig. 2 is a partial cross-section of the side wall of the cup of Fig. 1;
Fig. 3 is a partial cross-section of the side wall of the cup of Fig. 1, where
the valleys
are on the inside surface of the cup;
Fig. 4a is a partial cross-sectional view of the side wall of Fig. 2, with
sample
dimensions from an upper portion of the preferred embodiment;
Fig. 4b is a partial cross-sectional view of the side wall of Fig. 2, with
sample
dimensions from the lower portion of the preferred embodiment;
Fig. Sa is a partial cross-sectional view of the side wall of Fig. 3, with
sample
dimensions from an upper portion of the preferred embodiment;
Fig. Sb is a partial cross-sectional view of the side wall of Fig. 3, with
sample
dimensions from the lower portion of the preferred embodiment;
Detailed Description Of The Preferred Embodiments:
The present invention will be described with reference to its preferred
embodiments,
and in particular with reference to an embodiment of a container used as a
drinking
cup.
As shown in Fig. l, one aspect of the present invention provides a drinking
cup 10.
Drinking cup 10 is preferably made of rigid, injection-molded plastic, but
other
suitable construction material may be used. Drinking cup 10 comprises a bottom
20
and a top rim 30, both the bottom 20 and top rim 30 have a generally circular
periphery in cross section. Side wall 40 extends from the bottom 20 to the top
rim 30.
Side wall 40 may include a lower portion 42, an upper portion 44 and a lip
portion 46.
In a preferred embodiment, lower portion 42 is of reduced cross section
relative to
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upper portion 44. Both the lower portion 42 and the upper portion 44
preferably have
a taper with a taper angle relative to vertical of about 2° to about
6°, preferably about
3.5°. The taper results in a drinking cup 10 with a bottom 20 of
smaller diameter than
the top rim 30. Side wall 40 comprises a plurality of vertically-oriented,
concave-
shaped valleys 50 and a plurality of reinforcing peaks or projections 52,
defined by a
respective pair of valleys 50. The lip portion 46 may be devoid of valleys 50
and
reinforcing projections 52.
As better shown in Fig. 2 and 3, the cross-sectional profile of side wall 40
may also be
described as a wall having repeating segments of conic cross-section 70 on a
surface
of the side wall 40. Where adjacent segments 70 join, the side wall 40 is at
its
thickest, while at the center of each segment 70, the side wall 40 is at its
thinnest.
Referring to Fig. 2, a partial cross-section is shown of one embodiment of
side wall
40 where the concave-shaped valleys 50 and projections 52 are located on the
outside
surface 48 about the periphery of the drinking cup 10. The inside surface 47
is
generally smooth.
Referring to Fig. 3, a partial cross-section is shown of another embodiment of
side
wall 40 where the concave-shaped valleys 50 and projections 52 are located on
the
inside surface 47 about the periphery of the drinking cup 10. In this
embodiment, the
outside surface 48 is generally smooth. This embodiment provides the added
benefit
that the outside surface 48 can be printed with various logos, pictures,
letters, etc., as
desired. As well, having the valleys 50 and projections 52 on the inside
surface 47
helps reduce the amount of foam created when a carbonated beverage, such as a
soft
drink, is poured into the cup 10.
A further embodiment of the present invention is illustrated in Fig. 4a and
4b. Fig. 4a
shows a partial cross-section of the side wall 40 at a location adjacent to
the top rim
30, and preferred dimensions of the concave-shaped valleys 50 and projections
52 and
the relative thickness of the side wall 40 at the center of the concave-shaped
valleys
50 compared to the thickness of the side wall 40 at the projections 52.
Preferably, the
width of the valleys 50 and their center-to-center spacing is about 0.140
inches,
whereas the wall thickness is 0.015 inches at the center of the valleys 50 and
0.024
inches at the projections S2.
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Fig. 4b also partially illustrates the side wall 40, but at a location
adjacent to the
bottom 20. As shown, preferably the width of the valleys 50 and their center-
to-
center spacing is 0.111 inches, less that that adjacent to the top rim 30
shown in Fig.
4a. In this embodiment, the width of the valleys 50 and their center-to-center
spacing
decrease from the top rim 30 to the bottom 20. It will be noted from Fig. 4b
that the
thickness of the side wall 40 at the center of the valleys 50 and at the
projections 52 is
the same as in Fig. 4a.
Fig. Sa and Sb illustrate a similar embodiment as Fig. 4a and 4b, however, the
valleys
50 and projections 52 are on the inside surface 47 of the side wall 40.
Otherwise, it
will be seen that the dimensions of the widths of the valleys 50 and their
center-to-
center spacing remains the same as for Fig. 4a and 4b, respectively.
It is to be understood that the dimensions referred to in this specification
are intended
to illustrate a preferred embodiment of the present invention, and not for the
invention
in its broadest sense. Dimensions of various elements of the cup 10, side wall
40,
valleys 50 and projections 52 spacing may vary without departing from the
scope of
the invention.
The preferred embodiments of the present invention allow for drinking cups to
be
made while decreasing material costs by about 25%, while cycle times for
molding a
cup is reduced by about 20 to 25%. This results in substantial savings over
time,
while maintaining acceptable cup rigidity.
Although the present invention has been shown and described with respect to
its
preferred embodiments, it will be understood by those skilled in the art that
other
changes, modifications, additions and omissions may be made without departing
from
the substance and the scope of the present invention as defined by the
attached claims.
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