Note: Descriptions are shown in the official language in which they were submitted.
1 lB1404
IMPROVEMENTS IN OR RELATING TO DRINKING
CUPS AND METHODS OF MAKING DRINKING CUPS
The present invention relates to nestable cups, par-
ticularly those cups in which hot beverages, such as coffee are
drunk, and to stacks of such caps, each cup containing one or
more beverage ingredients.
It has long been known that a single walled cup does
not present a very good thermal barrier to insulate the fingers
of a person holding such cups containing a hot beverage from the
heat given out by that beverage.
Various proposals have been made for cups which could
provide better heat insulation, such as "double walled" cups.
United States Patent No. 2,493,633, and British Patent No.
1,325,230 both describe and illustrate double-walled containers.
These containers suffer from the disadvantage that a considerable
amount of material is required for their manufacture.
Alternatively, cups have been provided with holders
or ear-like handles.
The present invention provides a nestable cup which
can be held by the user when it contains hot water or hot bev-
erage and which is simple and economic to manufacture.
According to the present invention, there is provided
a nestable cup formed of thermoplastics material and comprising
a base, a wall integral with and upstanding from the base to de-
fine therewith a reservoir for liquid, and a turned-over, out-
wardly and downwardly extending collar circumjaoent the wall and
spaced therefrom with the juncture of the wall and collar provid-
ing a lip, the collar having an upper portion and a lower por-
tion and an outwardly and downwardly extending shoulder there-
between, the shoulder merging at shallow angles with the upper
and lower portions and increasing the rigidity of the collar
-1-
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such that when the collar is normally gripped by a user, it
remains spaced from the upstanding wall, the collar extending
a distance between 20 and 30 mm. below the lip to facilitate
gripping by the user.
In preferred construction, the distance between the
lip and the shoulder is approximately 1/3 the width of the
collar.
While any thermoplastics material may be used to form
the cup, currently commercially suitable materials include poly-
styrene, acrylonitrile/butadiene/styrene, and polypropyleneresins, optionally filled with, for example, talc or chalk for
additional strength. The use of barrier resins or laminates/
coextrusions is preferred since they improve the shelf life
of beverage ingredients. Because of the relatively low soften-
ing point polyvinyl chloride and some acrylonitrile/butadiene/
styrenes cannot be used for cups from which very hot beverages
are to be drunk, although they can be used for warm beverages.
When the cups are stacked the top cup can be fitted
with a plug or snap-on cap to retain the beverage ingredient
in the cup. Alternatively, a "dummy" cup which does not contain
any ingredient may be useful. A plug is to be preferred to a
snap-on cap when the stack is wrapped since the plug allows the
enveloping film to be drawn into the top aperture region of the
stack of cups and enables adequate top pressure to be obtained.
Preferably the wrapped stack should be under a top to bottom
pressure sufficient to prevent seepage of the beverage ingred-
ients from the cups. Preferred methods of wrapping are des-
cribed in United Kingdom Patent No. 1,539,729.
Specific embodiments of the invention will now be
described with reference to the accompanying drawings in which:
Figure 1 is a side elevation, partially in section,
of an embodiment of the cupi
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Figure 2 is an enlarged cross-sectional view of the
tops of two cups of the type shown in Figure 1 in a nesting
xelationship;
Figure 3 shows a manufacture of a cup of the present
invention with the apparatus in side view; and
Figure 4 shows from above a batch of twelve cups being
made in accordance with the method of manufacture shown in Fig-
ure 3.
Figure 1 shows the cup generally indicated at 1 hav-
ing a generally cylindrical base 2 with an upstanding integral
wall formed around its periphery. The free end of the wall 3
is turned over to form a lip 5 and an outwardly and downwardly
extending collar 6 which preferably has a depth below the lip
of 20 to 30 mm.
The collar 6 extends circumjacent the top of the upward-
ly extending portion of the wall 3 and is spaced therefrom. The
collar 6 may be provided with a ring of vertically extending
ribs 7 extending around its centre portion to increase the
rigidity of the collar.
It will be appreciated that the shape and thickness of
the collar may be considerably varied from that shown in Figures
1 and 2 and that the ribs 7 may be omitted. The essential re-
quirement for the collar 6 is that when it is gripped by a user
it remains spaced from the upwardly extending portion of the
wall 3.
The collar 6 has an upper portion 8 which extends
downwardly parallel to the upwardly extending portion of wall 3
and a flared skirt portion 9 which diverges away from the up-
wardly extending portion of wall 3.
The collar 6 has an outwardly extending and downwardly
inclined shoulder 13 between the upper portion 8 and lower por-
tion 9. It will be noted in this case that the lower portion 9
, ~ -.~
"
extends vertically. The provision of the shoulder 13 increases
the rigidity of the collar and indeed the provision of such a
shoulder alone, without the ribs 7, can provide sufficient
rigidity in the collar.
The lower portion 9 of the collar may be provided with
indents, not shown, which provide gripping points for the user's
fingers and increase the rigidity of the lower portion 9 of the
collar 6.
The cup 1 may be further provided with an inwardly
extending annular internal shoulder 10, which is shown in Fig-
ure 1, for supporting a like cup in a nesting relationship.
The base 2 of the cup 1 may have a central dome shaped
portion (not shown) which is provided both to give strength to
the cup 1 and to resist inversion of the base 2, which inversion
can occur when a hot liquid is poured into the cup 1.
When stacked the bases 2 of the nested cups together
define a space therebetween. This space can contain one or more
ingredients, such as coffee powder, for a beverage when the cup
is stacked.
It will be noted that the flared portion 9 of the
collar 6 allows the upper cup to be nested in the lower cup in
such a way as to r~adily allow the lower cup to be withdrawn
from the stack.
In use a hot liquid is poured into the cup 1 to make
a beverage from the dried ingredient, not shown, contained in
the cup. The user can then grip the cup by means of the collar
6. The arrangement of the shape and rigidity of the collar is
such that when the cup is gripped under normal pressures the
collar remains spaced from the upwardly extending portion of
the wall 3. The air within this space is a reasonably good heatinsulator and thus to all intents and purposes heat is only
conveyed from the hot beverage to the user's fingers by conduc-
l ~61404
tion of the heat from the liquid up the upwardly extending por-
tion of the wall 3, through the lip 5 and down the collar 6.
It will be appreciated that the length of this path is
considerably greater than the thickness of a normal thermoplas-
tics cup and therefore the cup is considerably more comfortable
to hold than a traditional thermoplastics cup~
It will be noted that in all of the constructions the
lip 5 offers an improved drinking surface over that of many
known cups, in particular because there is no need when making
the cups to roll the rim as is normally an additional operation
in those cups which are manufactured by thermoforming.
The drinking surface can be further improved if the
ribs 7 are omitted and preferably the distance between the
lip 5 and the shoulder is approximately 1/3 the width of the
collar 6.
Figures 3 and 4 show a method of thermoforming the cups
of Figures 1 and 2. In Figures 3 and 4 a sheet of thermoplastics
material 14 is positioned under a heater 15 which heats the
sheet 14 radiantly. This is shown in position A. The sheet
of material 14 is then gripped at its edges by means not shown,
projected forward into a position above a water cooled female
mould 16 (position B).
A clamp 17 is then applied around the cavity 18 of
the mould 16. The positiOn of clamp 17 in relation to mould 16
depends on whether the material from an area of sheet larger
than that of the mould aperture is required to make the forming.
The mould 16 is then moved upwardly towards the sheet material
14 and during this operation air is blown from both inside and
outside the mould 16. Air vents, not shown, are provided in
the mould 16 for this purpose. The air pressure forces the sheet
of material 14 into a position shown at C. A heated mechanical
punch (not shown) shaped to the interior of the mould forces
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the material 14 down into the mould 16 where it adopts the
shape of the interior of the mould. Air is expelled from the
mould to the air vents (not shown). If desired, the explusion
of air can be assisted by the use of vacuum exhaustionO
During a further stage D the forming 19 is cut from
the sheet 14 and the remaining part can be reprocessed. The
process described is an intermittent process and whilst one
part of a sheet of material is being heated another part is
being thermoformed and in another part formings are being cut
from the sheet.
It will be appreciated that it is the unitary construc-
tion of the cups 1 which facilitate their easy construction.
It will further be appreciated that alternatively
the cups can be formed by injection moulding or injection blow
moulding.
