Lid for drinks container

The vacuum-formed plastic lid for a large disposable container of liquids includes a pouring spout formed into the rim of the lid. A portion of the lid can be torn out, and the liquid poured through the hole. A well in the lid constitutes a receptacle for storing and carrying a number of empty, smaller, drinking cups. The lid includes a ridge, and two cuts, one either side of the ridge. When a person squeezes the ridge, the cuts spread over the ridge, until they meet. The ridge constitutes also a handle, by which the person can manipulate and remove the tear-out portion.

This invention is in the field of drinks containers of the disposable kind. 
Such containers are made typically of waxed paper or polystyrene or other 
suitable materials. 
Because of the difficulty a person experiences in carrying several drinking 
cups full of liquid, even when the cups have lids, it is desirable to 
supply the liquid in a single large container. Such a container may have 
its own lid, and the several (small) drinking cups may then be empty when 
they are being carried. Thus, by the use of a large container a person at 
a sporting event for example may carry drinks for several people back to 
his seat without difficulty. Furthermore, a vendor can dispense the liquid 
into the large container more quickly and more easily than into several 
small cups. 
The invention relates to the construction of the lid for the large 
container. The invention is concerned only with lids made from 
vacuum-formed sheet plastic. (Sometimes, lids can be of injection moulded 
plastic, but the production processes are so widely dissimilar that the 
advantages and restrictions of injection-moulding are quite different). 
In the invention, the lid is provided with a ridge, and is provided with 
with two cuts, one each side of the ridge. When a person squeezes the 
sides or walls of the ridge together, the cuts start to elongate. The 
direction in which the cuts start to elongate then can be easily 
controlled by the person's finger and thumb as he squeezes the ridge. The 
cuts elongate towards and across the ridge, and the person can easily 
manipulate and finally remove a tear-out portion of the lid. 
The liquid is poured out of the hole left by the tear-out portion into the 
drinking cups, as required. It is important that the lid retains 
structural strength during the pouring stage: thus, it is essential not to 
remove a sector of the rim of the lid, i.e., that part of the lid that 
snaps over the flange of the container, since that would markedly weaken 
the lid. In the invention, the hole does not, therefore, quite reach the 
rim of the lid. Hence, not quite all of the liquid can be poured out. 
However, when the container is almost empty, the lid can be removed at 
that time from the container for the purpose of pouring out the last 
drops. 
The lid may be provided with a formed spout, to ease the act of pouring. 
Naturally, the spout will be in line with (i.e. at the same orientation 
as) the cuts. 
The ridge may be arranged to surround a well that is dimensioned to accept 
and to grip the drinking cups. With the cups in the well, the container 
and the cups can be safely carried just with one hand.

The lid 20 includes a well 21, a ridge 23, a trough 24, and a rim 25. All 
are circular, and concentric. The ridge 23 is formed with an inner-side 
wall 26 and an outer side wall 27. The ridge 23 also has a top 29. 
An outer cut 30 is formed in the bottom 31 of the trough 32. An inner cut 
34 is formed in the bottom 35 of the well 21. Both cuts 30,34 are made by 
a simple shearing operation. (It is a simple everyday operation to shear 
through a plastic lid at a place on the lid--as in the bottoms 
31,35--where the plastic lies in the plane of the lid. It would be very 
expensive however to cut through the plastic of the side walls 26,27). 
The lid 20 also is provided with a spout 36. 
In use, the lid 20 is snapped over the flange 37 of a large container 39, 
which is made in the conventional manner from waxed paper. Drinking cups 
of the stacking kind, one of which 42 is shown, may be placed in the well 
21. The well 21 is dimensioned so that it will grip the cut 42. Thus the 
assembly of container 39, lid 20, and cups 42 becomes a single unit. The 
unit is very much easier to carry than a quantity of separate drinking 
cups. 
To pour the drinking liquid into the cups 42, the user removes a removable 
portion 43 from the lid 20. He places his forefinger and thumb one either 
side of the ridge 23, i.e., one inside and one outside. He then squeezes 
his thumb and finger together--an action which causes the walls 26,27 to 
move together. The action also causes the cuts 30,34 to open. 
It might be considered that only the cuts 30,34 are important in defining 
the removable or tear-out portion 43. However, the ridge 23 plays an 
important role in controlling and defining the path along which the cuts 
30,34 will elongate. 
If there were no ridge 23 at all, (i.e. if the material were flat between 
the cuts) and if the person simply pushed downwards between the cuts, then 
the cuts would tend to elongate in the same direction as that of the cuts 
themselves. Thus, it would be very difficult to actually remove a portion 
of the lid. Even if a hole were made, a flap of the material would 
inevitably be left dangling inside the container. The flap would act as a 
valve, and would occasionally plug the hole, and generally would make 
pouring the liquid an uncontrolled, hazardous, operation. 
It is an important feature that the ridge 23 acts as a handle, to permit 
the tear-out portion to be worked and manipulated, and to be finally 
separated and removed from the lid. 
It might be considered that the function of a handle could be provided if 
the rib 23 were not continuous. Thus, the "handle" might be thought to 
possibly consist of a raised button of material between the cuts 30,34. In 
this case, the bottoms 31,35 of the trough 24 and the well 21 would 
comprise one continuous flat surface. 
Even though an isolated button like that might function as a handle, the 
manner in which the cuts 30,34 tend to elongate would still be largely 
uncontrolled. It is a feature of the invention that the ridge 23 is 
continuous, i.e., that the side walls 26,27 are continuous, in the region 
between the cuts 30,34. It has been found that when the ridge is squeezed, 
the cuts 30,34 tear and elongate in a direction which is substantially 
straight across the ridge. The direction in which the cuts 30,34 elongate 
is defined and controlled. It becomes very easy to remove the tear-out 
portion 43, and to remove it without exerting a large force, and without 
taking more precautions than a person would expect to have to take to 
avoid spilling the contents of the containers. 
The reason why the continuous ridge 23 is so effective may be due to a 
number of factors. First, the ridge 23 makes the lid 20 very rigid in the 
vertical direction in the region between the cuts 30,34--much more so than 
in regions where the lid is simply flat. Therefore the material does not 
tend to bend and twist as much as it would if it were flat. This rigidity 
therefore enhances the controllability of the direction of tearing. 
The second reason is that the walls 26,27 of the ridge are very thin. This 
is due to the vacuumforming process, in which the material, prior to 
forming, is a flat sheet. The part of the material that goes into forming 
a vertical or nearly vertical wall is that part that lies in the vertical 
projection of the wall. The material tends not to slip over the forming 
tools. Hence, the vertical walls are comprised of stretched material, and 
are therefore thin. The more nearly vertical the wall, and the higher the 
wall, the thinner it will be. The walls 26,27 of the ridge 23 are 
therefore thin, and easily able to accept and continue a tear. The top 29 
of the ridge 23 of course will not be stretched, but once the cuts have 
reached the top 29 of the ridge 23, it is an easy matter finally to tear 
through the top 29. 
The bottoms 31,35 of the trough 24 and well 21 are sloping, as may be seen 
in FIG. 2, so that the walls are not stretched and thinned quite so much 
at the orientation directly opposite the spout 36. The material that makes 
up the spout 36 is not thinned very much either, since it is not so nearly 
vertical as the walls 26,27. Thus, the thinnest part of the material of 
the lid 20 is in the walls 26,27, at the orientation in line with the 
spout 36: i.e., directly where it is required for the cuts 30,34 to 
elongate. 
The cuts 30,34 are preferably straight. The tools which shear the cuts are 
then much easier to make than they would be if the cuts were, for example, 
curved. However, the outer cut 30 may be curved, so that the cut follows 
the line of the spout 36. The outer cut 30 might alternatively be provided 
with cross-cuts (not shown) at or near its ends, for the purpose of 
directing--even more controllably--the elongation of the cut 30 towards 
the ridge 23. 
Thin sheet polystyrene, of the kind used in making lids, has the property 
that the material is considerably easier to tear along the "grain" of the 
material than across the grain. Hence, the lid should be orientated during 
manufacture such that the cuts 30,34 lie across the grain. 
The shearing operation is carried out at a different stage in the vacuum 
moulding operation, so it is necessary to take steps to ensure that the 
cuts 30,34 are at the same orientation as the spout 36. However, this is 
usually no problem. 
The cuts 30,34 preferably should be about 2 cm long, i.e., the width of the 
end of a thumb. The outer wall 27 preferably varies from a height of about 
7 mm at the orientation of the spout 36, to a height of about 3 mm 
opposite the spout 36.