Abstract:
Methods and apparatus for opening containers such as cigarette packages without damaging the contents of the containers. If desired, the methods and apparatus may be extended to include emptying the containers after they have been opened.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to methods and apparatus for opening closed containers, and more particularly to methods and apparatus for opening containers (such as cigarette packages) which contain relatively fragile contents. The invention also relates to methods and apparatus for emptying such containers once they have been opened. 
     Cigarette manufacturers frequently have a need to open large numbers of cigarette packages. For example, it may be necessary to open cigarette packages as part of a quality control process, or to make cigarettes available for smoking tests or other tests of the cigarettes. It may also be necessary to open packages found to be defective in order to recover the cigarettes for repackaging. 
     Heretofore, cigarette packages have been opened by hand. This is a tedious and time-consuming task which results in many damaged and unusable cigarettes. 
     In view of the foregoing, it is an object of this invention to provide methods and apparatus for automating the opening of closed containers such as cigarette packages. 
     It is a further object of this invention to provide methods and apparatus for automating the opening and emptying of closed containers such as cigarette packages. 
     SUMMARY OF THE INVENTION 
     These and other objects of the invention are accomplished in accordance with the principles of the invention by providing methods and apparatus for opening containers having parallel top and bottom walls, parallel front and back walls, and parallel left and right side walls in which the left and right side walls are cut through substantially continuously between the top and bottom walls, the front wall is cut through substantially continuously between the left and right side walls, and the container is opened by opening up the cut in the front wall. If the container is to be emptied, the foregoing container processing preferably takes place with the back wall facing down, and after the cut in the front wall has been opened up, the container is inverted so that the back wall faces up. 
    
    
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the invention. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a simplified, partial, plan view of a portion of an illustrative embodiment of the container opening apparatus of this invention. 
     FIG. 1A is a more detailed view taken generally along the line 1A--1A in FIG. 1. 
     FIG. 2 is a view taken along the line 2--2 in FIG. 1. 
     FIG. 2A is a perspective view of a package prior to processing. 
     FIG. 2B is a perspective view of the package of FIG. 2A after an initial processing step. 
     FIG. 3 is a view taken along the line 3--3 in FIG. 1. 
     FIGS. 3A-3C are perspective views of the package of FIGS. 2A and 2B after successive further processing steps. 
     FIG. 4 is a more detailed plan view of a portion of the apparatus of FIGS. 1-3 (i.e., the initial portion of the second conveyor). 
     FIG. 5 is an elevational view, partly in section, of the apparatus of FIG. 4. 
     FIG. 6 is a view taken along the line 6--6 in FIG. 5. 
     FIG. 7 is a view taken along the line 7--7 in FIG. 5. 
     FIG. 8 is a more detailed plan view of another portion of the apparatus of FIGS. 1-3 (i.e., an intermediate portion of the second conveyor). 
     FIG. 9 is an elevational view, partly in section, of the apparatus of FIG. 8. 
     FIG. 10 is a view taken along the line 10--10 in FIG. 9. 
     FIG. 11 is a more detailed plan view of yet another portion of the apparatus of FIGS. 1-3 (i.e., a later intermediate portion of the second conveyor). 
     FIG. 12 is an elevational view, partly in section, of the apparatus of FIG. 11. 
     FIG. 13 is a view taken along the line 13--13 in FIG. 11. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Although this invention is applicable to opening many other types of containers, the invention will be fully understood from the following explanation of its application to opening conventional softsided cigarette packages. 
     As shown in FIG. 2A, a typical cigarette package 10 has parallel top and bottom walls 12 and 14, parallel front and back walls 16 and 18, and parallel left and right side walls 20 and 22. It is to be understood that terms like &#34;top,&#34; &#34;bottom,&#34; &#34;front,&#34; &#34;back,&#34; &#34;left,&#34; and &#34;right&#34; are used herein and in the appended claims solely for convenience and clarity, and that these terms are applied to the container without regard to how the container may be oriented for any other purpose. For example, top wall 12 may in fact be the bottom wall of the container when considered from the standpoint of how the container is normally held in order to read the labelling printed on the container. However, that is irrelevant for present purposes, the naming of the various container walls being purely arbitrary herein. 
     As is best seen in FIG. 2, cigarette packages 10 to be opened are loaded, back wall down, into a hopper 30 located above one end of conveyor 40. Hopper 30 is oriented so that the top wall 12 of each package is perpendicular to the axis of motion 42 of the adjacent portion of conveyor 40. Conveyor 40 has a plurality of pusher bars 44 projecting out from the conveyor path and spaced along the length of the conveyor. The spacing between adjacent bars 44 is greater than the height of each package 10 (i.e., the distance between the top and bottom walls of each package). Accordingly, each time a bar 44 passes under hopper 30, it removes one package from the bottom of the hopper and conveys that package from left to right as viewed in FIG. 2. 
     After leaving hopper 30, each package 10 is conveyed by conveyor 40 between a pair of rotating circular saws 50a and 50b. Saw 50a cuts through right side wall 22 parallel to front wall 16 and continuously from top wall 12 to bottom wall 14 as shown at 52a in FIGS. 2 and 2B. Indeed, the cut 52a produced by saw 50a even extends a short way into top and bottom walls 12 and 14. Saw 50b forms a similar cut 52b in left side wall 20. Cuts 52 are preferably at a location where the saws 50 producing those cuts will not damage the contents of package 10. In the preferred embodiment, for example, package 10 contains 20 cigarettes 24 in three rows parallel to front wall 16. In particular, there are seven cigarettes in each of the front and back rows, and six cigarettes in the intermediate row. Accordingly, the left- and right-most cigarettes in the intermediate row are spaced in from left and right side walls 20 and 22, respectively. This makes the region adjacent the ends of the intermediate row a good location for forming cuts 52. For other reasons that will become apparent as the description proceeds, it is also generally desirable to form cuts 52 as close to front wall 16 as possible. Thus cuts 52 are preferably formed adjacent the ends of the intermediate row of cigarettes, but also closer to front wall 16 than to back wall 18. 
     Although represented more simply in FIGS. 1 and 2, conveyor 40 may actually comprise a pair of opposing. stationary U-shaped channels 46a and 46b (FIG. 1A) through which packages 10 are pushed by pushers 44 mounted on chain drive 48. At the locations of saws 50, channels 46 are slotted to allow the saws to pass through and operate on package 10 as described above. 
     At the end of conveyor 40, each package 10 is transferred to conveyor 60, which is oriented at a right angle to conveyor 40. Like conveyor 40, conveyor 60 has a plurality of pusher bars 64 extending out from the conveyor path for causing successive packages 10 to travel with conveyor 60 parallel to axis 62. The spacing between adjacent bars 64 is greater than the width of packages 10 (i.e., the distance between left and right side walls 20 and 22). The spacing between adjacent bars 64 and the speed of conveyor 60 are also such that packages 10 are conveyed away by conveyor 60 at the same rate that they leave conveyor 40. Again, although represented more simply in FIGS. 1-3, conveyor 60 may actually (1) support packages 10 by means of stationary plate 68a (FIGS. 4, 5, 7, and 8), (2) guide packages 10 between stationary side rails 68b and 68c (FIG. 8), (3) hold down packages 10 by means of stationary hold-down plates 68d and 68e (FIG. 8), and (4) drive pusher bars 64 by mounting them on a pair of chain drives 68f and 68g (FIGS. 5-7 and 10). 
     When each package 10 reaches location A (FIG. 3) on conveyor 60, a blast of air is applied by nozzle 70 (FIGS. 8-10) to cause the portion of right side wall 22 above cut 52a to bulge out. While this portion of package 10 is thus bulged out, knives 80a and 80b (FIGS. 1, 3, and 8-10) are recipocated up through the path of conveyor 60 to form two, small, laterally spaced cuts 82a and 82b (FIG. 3A) through the bulged-out portion of right side wall 22. In particular, each of cuts 82 extends (parallel to top and bottom walls 12 and 14) from front wall 16 to cut 52a. The portion of front wall 22 between cuts 82 forms a tab 84 which is held up substantially parallel to front wall 16 by the air blast mentioned above. Conveyors 40 and 60 preferably both stop momentarily during operation of knives 80. The motion of knives 80 is produced by conventional pneumatic or mechanical actuator apparatus 86 (FIG. 10). 
     As soon as cuts 82 have been formed, knives 80 reciprocate back down through the path of conveyor 60, and conveyors 40 and 60 start moving again. An air blast from nozzle 72 (FIGS. 8 and 9) keeps tab 84 up so that as conveyor 60 continues to move the container along, the relatively narrow and thin initial portion 92 of stationary member 90 passes under flap 84 and enters package 10 immediately below front wall 16. In order for member 90 not to disturb the contents of package 10, initial portion 92 preferably cooperates with flap 84 to raise front wall 16 slightly as initial portion 92 enters the package. 
     Shortly after initial portion 92 enters package 10, front wall 16 is cut through by rotating circular saw 100. (Saw 100 can be rotated in either direction, and indeed it may be preferable to rotate it in the direction opposite the direction indicated in the drawings in order to help pull package 10 onto initial portion 92.) Saw 100 cuts through front wall 16 between left and right side walls 20 and 22. The resulting cut 102 (FIG. 3B) is parallel to top and bottom walls 12 and 14, and in the preferred embodiment is midway between those walls. In addition, because flap 84 is parallel to front wall 16, it is also cut through. And because initial portion 92 forces the portion of left side wall 20 above cut 52b to pivot out and up parallel to front wall 16, that portion of left side wall 20 is also cut through. As is best seen in FIGS. 4, 5, and 7, the upper portion of the front of each pusher 64 is relieved or recessed at 66 to allow initial portion 92 to pivot the upper portion of left side wall 20 out as described above. To ensure that saw 100 does not damage the contents of package 10, saw 100 is preferably disposed above initial portion 92 and cooperates with a slot 92a in initial portion 92 to form cut 102. 
     After passing saw 100, package 10 is forced by conveyor 60 onto the intermediate portion 94 of member 90. Whereas initial portion 90 is relatively narrow as viewed in FIG. 1 (i.e., preferably narrower than flap 84 measured between cuts 82), intermediate portion 94 tapers out in width in the direction of motion of the packages on conveyor 60 until it is wider than the distance between top and bottom walls 12 and 14. Accordingly, intermediate portion 94 forces cut 102 to open up by pivoting the two portions of front wall 16 (and the connected portions of left and right side walls 20 and 22) up, out, and away from the remainder of the package as shown in FIG. 3C. This completely opens package 10 and leaves two large flaps 104a and 104b extending out from the respective opposite ends of the package. To help make sure that the cigarettes 24 remain in package 10 as it is being opened, floating weights 96 (FIGS. 11 and 12) press down lightly on the cigarettes as the package passes under this portion of member 90. This hold-down action is continued by spring finger 98. 
     Flaps 104 are formed in part by folding the bases of those flaps over rails 110 (FIGS. 11 and 13) which extend generally parallel to top and bottom walls 12 and 14. Flaps 104 are forced down over these rails by hold-down plates 120. Although generally parallel to top and bottom walls 12 and 14, rails 110 preferably diverge slightly from one another in the machine direction in order to pull top and bottom walls 12 and 14 slightly away from the ends of cigarettes 24. This helps ensure that all of cigarettes 24 spill out of package 10 when the package is subsequently inverted. 
     After top and bottom walls 12 and 14 have been pulled apart as described above, each of flaps 104 is engaged between a wheel 130 and a pressure belt 132. Wheels 130 are concentric with the adjacent end of conveyor 60, and rotate at the same angular velocity as that end of the conveyor. Accordingly, elements 130 and 132 cause package 10 to move around the end of conveyor 60, thereby inverting the package and allowing cigarettes 24 to spill out into hopper 140. Pressure belts 132 then convey the empty packages to hopper 150.