A twist-on/twist-off resealable assembly for a can-end, such as a metal can used in the beverage industry includes a first set of knuckles formed on the can body near its top opening. A plurality of cooperating fingers on the inside of the can lid engage the knuckles so that the lid is tightened by its progressive downward motion as the lid is rotated. The lid also includes a weakened or frangible portion for forming a straw opening. A second set of knuckles are located below the top set of knuckles for engagement by fingers extending from a pilfer-proof ring. The twist-off can lid may be made from the same metal as the can body or alternatively from a transparent plastic material or a combination of metal and plastic.

BACKGROUND OF THE INVENTION 
The present invention relates to a twist-on/twist-off, resealable assembly 
for a can end, such as a metal can used in the beverage industry. More 
specifically, the present invention relates to a resealable can end 
assembly which is easy to open and reseal by twisting of the closure on 
the can end. 
Current can-ends for beverage cans are generally of the "ring-pull" or 
"press-down-stay-on-tab" type and have some disadvantages. 
The are generally not resealable. The tabs are difficult to open and the 
opening size/shape are not ideal for drinking. Furthermore, the product is 
not visible through the can-end. 
Most current can-ends for beverages are aluminum, and since these are 
joined to the can-body by roll-seaming, recycling is more difficult when 
using steel-body cans. A design of a can-end which is either less firmly 
attached to the body, or easily produced from either steel or aluminum, 
would be environmentally-friendlier by enabling single-material packages. 
Finally, designs of can-ends which enable easy inclusion of a hidden-gift, 
or other promotional material, which is only accessible when the can is 
opened, would give significant promotional advantages in the market-place, 
compared with current can-ends. 
SUMMARY OF THE INVENTION 
Accordingly, it is the object of this invention to provide can-ends 
systems, which are recloseable, easy-open, easy-drink; which can offer 
product visibility; and which enable single-metal can-systems and hidden 
gift promotional possibilities. 
The foregoing and other objects of this invention are fulfilled by 
providing a resealable can end assembly comprising: 
a cylindrical can body having an open end and a closed end with a closure 
engaging finish extending around the exterior surface of the can body 
adjacent the open end; 
a cylindrical closure having a depending peripheral skirt for operatively 
engaging said finish; 
a first type of spaced knuckles on said finish, said knuckles having 
angular surfaces on undersides thereof; 
a plurality of spaced fingers on the skirt for engaging the angular 
surfaces on the knuckles when the closure is tightly secured to the open 
end by relative rotation of said skirt and finish in a closing direction, 
said fingers releasing from the knuckles in response to relative rotation 
in an opening direction; 
a second type of spaced knuckles disposed on the finish of the can; and 
a pilfer-proof ring detachably secured to the bottom of said skirt having 
projecting fingers for engaging said second type of knuckles. 
The can-lid with a twist-on closure feature, includes protrusions 
("knuckles") formed on the can-body near its top opening, on which the 
fingers of the lid locate so that the lid is tightened by its progressive 
downward motion, when it is turned and the said fingers are forced to 
follow the downward angle on the bottom of the "knuckles". The lid has two 
sections separated by a deliberately-weakened portion, which is achieved 
by perforating the lid-material, or similar means. During can closing, the 
lower part of these said two sections is forced onto further "knuckles" 
which are formed near the top of the can-opening, and arranged so that 
this section can no longer be removed from the can-body, and so that the 
action of opening breaks the said weakened-portion, separating the said 
two sections and providing evidence of opening. The twist-off can-lid can 
be made from the same metal (or material), as the can body, or 
alternatively from a transparent plastic (enabling product visibility), or 
from a metal/plastic combination (enabling additional pressure-holding 
strength as well as product visibility) 
Further scope of applicability of the present invention will become 
apparent from the detailed description given hereinafter. However, it 
should be understood that the detailed description and specific examples, 
while indicating preferred embodiments of the invention, are given by way 
of illustration only, since various changes and modifications within the 
spirit and scope of the invention will become apparent to those skilled in 
the art from this detailed description.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now to FIGS. 1A-1D, depicted thereat is an embodiment of the 
invention comprising a twist-on can lid 1 for a can 5. The lid 1 includes 
a skirt having two separable sections, an upper body section 1A and a 
lower body section 1B. The lower body section 1B comprises a pilfer-proof 
ring 8. The two body sections 1A and 1B can be separated by twisting at a 
weakened frangible perforation shown by reference numeral 10. 
FIG. 1A shows the top view of the lid 1 with a ring-pull 2A connected to a 
frangible opening 2B for a straw. The user can either twist-off the lid 1 
to open the top of the can 5 fully, or use the straw opening 2. FIG. 1B 
shows the closing features of the lid 1, where a first set of inwardly 
projecting fingers 3 located on the upper body portion 1A and adapted to 
grip a multiplicity of "knuckles" 4 pressed into the can 5 sidewall in 
such a way as to give a progressive downward motion ("twist-on") to the 
lid 1 as it is rotated, compressing seal 9. A multiplicity of smaller 
locating "knuckles" 6 are also pressed into the can 5 sidewall below the 
"knuckles" 4 and these are gripped by a second set of pilfer-proof fingers 
7 located on the pilfer-proof ring 8 and which curve inwardly as shown in 
FIG. 1C. The locating "knuckles" 6 are shaped so that once the 
pilfer-proof fingers 7 pass over them to the closed position, these 
pilfer-proof fingers 7 prevent further rotation and removal of the 
pilfer-proof ring 8 from the body of the can 5. The lid 1 has a 
top-surface which enables normal nesting of other can bases placed on top 
of it. FIG. 1C shows the action of the "knuckles" 6 and the fingers 3, 
which provide the "twist-on" closing function, and of the pilfer-proof 
fingers 7 and locating "knuckles" 6, which locate the pilfer-proof ring 8. 
FIG. 1D shows the side of the lid 1 and in particular the fingers 3, the 
pilfer-proof ring 8 forming the lower section 1B, the frangible 
perforation 10 and a stay-on strap 11A comprising a thin flexible strip of 
material including a bend therein connected between the upper body section 
1A and the lower section 1B, i.e. the pilfer-proof ring 8. The flexible 
strip 11A is located in the rectangular aperture 11B in the lower section 
1B and maintains a connection between the elements 1A and 1B when the 
perforation 10 is broken such as by twisting and the upper body section 
11A of the lid is removed from the top of the can 5. 
FIGS. 2A-E show a variation of the embodiment in FIG. 1, wherein FIG. 2A 
the principal difference is the replacement of lid 1, in FIG. 1, by two 
distinct parts. One part is a metal holding-ring 20, which incorporates 
the fingers 3, and the second part is a plastic cover 21, preferably of 
transparent material, which incorporates the pilfer-proof ring 8, the 
pilfer-proof fingers 7 as shown in FIG. 2E and the stay-on strap 11A' 
which also comprises a thin flexible strip of material but now is in the 
form of a diagonal member across a rectangular shaped aperture 11B' in 
lower lid section 1B. In both embodiments, the shape of the hold-on straps 
11A and 11A'maintains a connection between the upper lid portion 1A and 
the lower lid section 1B once the frangible perforation is broken. In FIG. 
2B the fingers 3 on the holding-ring 20 connects with inclined lower 
surface of the "knuckles" 4 on the can 5 via respective slots 21' formed 
in the plastic cover 21, and the pilfer-proof fingers 7 connect with the 
locating knuckles 6 in the can 5, similarly as in FIG. 1B. FIG. 2C shows 
the action of knuckles 6 and fingers 3, which provide the same twist-on 
closing function as the embodiment in FIG. 1. FIG. 2C also shows the 
pilfer-proof fingers 7 and locating-knuckles 6, which locate the 
pilfer-proof ring 8. FIGS. 2D and 2E show further detail of the features 
of holding-ring 20 and the plastic cover 21 and the thin flexible hold-on 
strip 11A' located in the aperture 11B' formed in the sidewall of the 
plastic cover 21 which essentially enable these two parts to fulfil 
together the same function as that described for the lid 1 in the 
embodiment shown in FIG. 1. 
By way of example, FIG. 3 shows promotional possibilities in conjunction 
with the twist-on-off lid 1 version demonstrated by FIG. 2. The metal 
holding ring 20 extends to cover the plastic cover 21 thus permitting a 
hidden compartment 60, which is usable for gifts, prizes, etc. A 
side-space 61 can also be created for labels, information material, etc. 
The underside 62 of the metal holding ring 20 can also be used for 
printing messages, collect-me-pictures, etc. 
The invention being thus described, it will be obvious that the same may be 
varied in many ways. Such variations are not to be regarded as a departure 
from the spirit and scope of the invention, and all such modifications as 
would be obvious to one skilled in the art are intended to be included 
within the scope of the following claims.