US3837519A

US3837519A - Container closure with opening indicators

Info

Publication number: US3837519A
Application number: US00324083A
Authority: US
Inventors: W Perry
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-01-16
Filing date: 1973-01-16
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24

Abstract

A tamper indicating closure for containers having a threaded section below the mouth and an annular locking shoulder below the threads, in which two or more tamper indicator extensions project down from the closure main body, and have horizontal cross slots and vertical score lines and their lower edges hooked to the locking shoulder, and such that the score lines rupture when the closure is removed. Score lines may be notched at the ends to provide rounded corners and projecting bosses shield the sharp edges. Alternative design comprises complete circle of rectangular segments below a ring of horizontal slots, and with the segments defined by vertical score lines extending from the lower edge up to bisect the wall material between adjacent slots, thus providing firm anchorage of upper corners of all segments after rupture of score lines. The preformed cup for the closure, prior to threading, is made with spaced depressions around the cylindrical side wall to provide concentric alignment of closure top panel and gasket on mouth during sealing and threading. Alternatively depression in top panel provides improved centering. Advantages of closure include less material and lower cost, more positive tamper indication, impossible to restore after tampering, free of sharp corners and sharp edges that cut fingers. A torquing mechanism is provided in the bottling line to insure uniform removal torque. Improvements apply to both prethreaded and threaded-on-neck types of closures in ductile metal or plastic.

Description

United States Patent [1 1 Perry CONTAINER CLOSURE WITH OPENING INDICATORS Walter Merton Perry, 76 Locust Hill Rd., Darien, Conn. 06820 Filed: Jan. 16, 1973 Appl. No: 324,083

[76] Inventor:

U.S. Cl. 215/7, 215/42 Int. Cl A61i 1/00, B65d 55/02 Field of Search 215/7, 42, 46 R References Cited UNITED STATES PATENTS 9/1969 Dorn et al 215/42 X 8/1973 Sourbet et al. 2l5/42 Primary Examiner-George T. Hall 51 Sept. 24, 1974 and vertical score lines and their lower edges hooked to the locking shoulder, and such that the score lines rupture when the closure is removed. Score lines may be notched at the ends to provide rounded corners and projecting bosses shield the sharp edges. Alternative design comprises complete circle of rectangular segments below a ring of horizontal slots, and with the segments defined by vertical score lines extending from the lower edge up to bisect the wall material between adjacent slots, thus providing firm anchorage of upper corners of all segments after rupture of score lines. The preformed cup for the closure, prior to threading, is made with spaced depressions around the cylindrical side wall to provide concentric alignment of closure top panel and gasket on mouth during sealing and threading. Alternatively depression in top panel provides improved centering. Advantages of closure include less material and lower cost, more positive tamper indication, impossible to restore after tampering, free of sharp corners and sharp edges that cut fingers. A torquing mechanism is provided in the bottling line to insure uniform removal torque. Improvements apply to both pre-threaded and threaded-onneck types of closures in ductile metal or plastic.

14 Claims, 17 Drawing Figures II 2a 30 n 2 3i 33 8 f v I2 @M J 2 m) l l lll r PATENTEU SEPZWM 33.37 519 sum 1 0r 2 1 WH M m Bill, 2 l D] M q 33 K Z D -m G Q Q 2'. F W m.

FIG. v6

FIG. 7

CONTAINER CLOSURE WITH OPENING INDICATORS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the threaded cap type of closure for use on containers which have a threaded mouth for receiving the closure. It is most often, but not necessarily, used on containers having contents which develop internal pressure, as from charged liquids. Most particularly it relates to such closures which incorporate visual indicating means to show the user whether or not the closure has been tampered with, or removed from the container subsequent to the initial filling and sealing. The indicating means in this type of closure usually makes use of a locking shoulder provided on the container neck, and positioned downwardly of and just beyond the threaded section. It also relates to the class of closure that can be screwed back on again, such that partial contents remaining in the container can be resealed for later use without appreciable loss of pressure.

The greatest field of use of the invention is for the type of construction in which the closure is drawn into the shape of a cup from ductile sheet metal material, generally thin hard temper aluminum alloy, and with the threads of the closure roll formed after the cup shaped blank is placed on the neck of the container so the threads match perfectly. It applies also, however, to cup shaped caps of metal or plastic which are prethreaded before application to the container. Further, the invention applies chiefly to the type of closure in which tamper proof indicating means remains attached to the closure. This leaves the neck of the container free of a part of the closure, such as the metal band left on the neck with some types used heretofore. Such bands have been found difficult to remove when the container is to be refilled, or the material of the container is to be recycled.

2. Description of Prior Art There are two commonly used pilferproof screw type closures for use on threaded neck containers. The first is covered by A. G. Osborne et al. U.S. Pat. No. 3,303,955, issued Feb. 14, 1967, and comprises a threaded-in-place closure with a pilferproof band which breaks off and remains on the neck after opening. The second is shown in H. R. Kutcher U.S. Pat. No. 3,601,273, issued Aug. 24, 1971, and teaches a similar threaded-in-place closure, but with a pilferproof band which has vertical weakening lines around its circumference which fracture when the closure is removed, but the band remains attached to the main body of the closure.

In both types the closure is applied in the following way, a description of which will more clearly show the improvements of my invention. As described in the Osborne et al. patent, the container has a threaded section just below a cylindrical sealing shoulder at the upper end of the container mouth. An annular downward facing shoulder is provided below the threads, to which the pilferproof band is locked. The cup shaped cap is usually pre-formed from 0.008 to 0.0095 thick hard temper ductile aluminum alloy sheet. The cap is made large enough on its inside diameter to fall down freely over the threads of the container mouth when it is applied at the entrance of the high speed bottling machine. There is a flat polyvinyl chloride sealing disc, or gasket, adhesively held inside the top panel of the closure, and in this construction the diameter of the disc must be large enough to permit its edges to be formed down around the end of the container mouth to provide side sealing around the exterior side cylindrical surface of the mouth.

After the container is filled and the cap positioned on the mouth, a pressure head comes down and reforms the closures top panel to a smaller diameter to provide the side sealing under high pressure. The pressure head then holds the sealing disc under high end pressure while thread forming rolls form the threads in the body of the closure matching those in the container neck underneath. The tamper indicating means of the Osborne et al. patent comprises a cylindrical band positioned just below the threaded section, and attached thereto by a circle of narrow bridges formed by cutting slots 'or lances through the metal around the circumference. During the thread rolling operation another roll turns the lower edge of the band under the locking shoulder of the neck. When the closure is unscrewed, the bridges break and the band remains on the neck as a tamper indicator, and this is objectionable when the container is to be refilled.

The Kutcher type closure is similar in structure and method of application to the Osborne, except for the pilferproof band. In the Kutcher the locking band has a series of vertical weakening lines formed in the band uniformly spaced around the circumference, and the band is attached to the body of the closure by a number of very narrow bridges, spaced by horizontal slots, and positioned at random relative to the lines of weakening. The lower edge of the locking band is also turned under the locking shoulder. When the closure is unscrewed, the turned-under lip of the band rides over the shoulder, placing the band in tension, and causing rupture at the weakening lines. Because of the very narrow bridges, the segments flare outward, some of the bridges break, and the sharp fractured ends of the segments are exposed, and can cut fingers.

This closure system has several disadvantages. The most serious one is that the sharp ends of the segments extend out at varying distances and tend to cut the tingers when removing or re-applying the closure. This is shown clearly in FIG. 4 of the drawings in U.S. Pat. No. 3,601,273. Another disadvantage is that often when the band is not rolled tightly under the shoulder the lines barely rupture, and the closure can be screwed back on, the segments pushed back into place, and the casual observer will not notice that the container has been opened. Both of these types of closure vary greatly in the amount of torque required to open them. The torque varies from 4 inch pounds to 17 inch pounds, and most users can not exert over 12 inch pounds with their fingers. This is also indicative of variation in tightness of seal. I find that the main reason for this large variation is failure to accurately center the closure sealing disc on the end of the container when the threads are formed. It is almost always off to one side, and this causes the PVC sheet to be squeezed thin under very high pressure on one side of the side seal, while the other side is barely compressed. This is because the cylindrical body of the cup has to be over-size to drop freely'over the threads of the neck, and the threads are therefore not effective in aligning the cup. Furthermore the diameter of the upper outside shoul- 3. der of the neck is much smaller than the threads, and of no use in assisting the alignment. Accurate alignment must be attained before the pressure head comes down, and this is part of my invention.

SUMMARY OF THE INVENTION The primary objective of the invention is to provide a threaded cap type container closure which has visible tamper indicating means to show whether the closure has been removed susequent to its initial application to the container, and to accomplish this without leaving part of the closure on the container.

Another important objective of the invention is to provide indicating means that do not present sharp surfaces that can cut the fingers when the closure is removed or re-applied. Another object of the invention is to provide indicating means which are more positively visible than used heretofore, and which can not be restored after the closure is re-applied.

Another objective of the invention is to reduce the cost of the closure by using less material for the closure blank, and at the same time enable its use on high speed bottling machines.

Another objective of the invention is to provide individual locking indicator extensions depending from the main body of the threaded closure which have their lower edges turned under the locking shoulder of the container, and which extensions each has one or more vertical score lines extending from the lower edge of the extension up toward one or more horizontal crosswise slots below the threaded section, and the action of which on removal of the closure is to rupture the material along the score line, and without appreciably flaring the ruptured ends outwardly where the sharp edges could cause cuts to the fingers during the opening or reuse of the closure.

Another objective of the invention is to provide two or more score lines on each indicator extension. Another objective of the invention is to align each vertical score line with a connection member extending to the main body of the closure, such that after rupture the material on each side of the score line remains firmly anchored at the upper end, and can not bend outward to present sharp corners to cut the fingers.

Another objective of the invention is to provide a series of score lines around the circumference of the closure in the lower extension material, and with each score line aligned with a solid connection to the main body of the closure, and such that each segment between score lines has its upper surface anchored at each end to prevent sharp corners from being presented.

Another objective of the invention is to extend to the complete circular band type of tamper indicator the arrangement whereby each vertical score line is positioned in line with the approximate center of a relatively wide bridge connection member to the main body of the closure, and thus each segment between score lines remains'anchored at its ends after opening.

Another objective of the invention is to form the closure cap before it is applied to the container with a series of inwardly projecting indentations spaced around its circumference to give the closure a firm elastic grip on the threads of the container to accurately center the top panel of the closure on the container mouth so the polyvinyl chloride gasket is uniformly compressed at all points around the circumference of the side seal during application, and in order to produce more uniform unlocking torques.

Another objective of the invention is to form a depression in the top panel of the closure in such a way as to give greater resilience to the top panel for more uniform unscrewing torque.

Another objective of the invention is to notch the score line at one or both ends in order to make rupturing easier, and at the same time to give rounded corners to prevent cutting the fingers, and to extend this feature to the complete circular type of tamper indicator.

Another objective of the invention is to provide embossed protruding surfaces adjacent to the fracturable score lines to hold the fingers clear of the sharp edges, and to extend this feature to other types of tamper pre vention systems.

Another objective of the invention is to provide tamper indicating means of the type that can be applied to pre-threaded closures of ductile metal or plastic composition.

Still another objective of the invention is to provide mechanical means in the bottling machine line whereby each closure will be tightened to a given desired torque, thus eliminating some closures that are too tight to loosen by hand.

DESCRIPTIQN OF THE DRAWINGS Other objectives of the invention will become apparent from the following detailed description and upon reference to the accompanying drawings in which:

FIG. 1 is an elevation with partial cross-section of the invention applied to a container closure of one of the preferred types in which the closure is drawn from thin ductile aluminum alloy to the shape shown prior to being threaded in place on the container neck, and the drawings shows the closure in place on the mouth of the container ready for threading.

FIG. 2 is a cross-section taken along line 2-2 in FIG. 1, and shows the score line and the protective bosses in one of the indicator extensions.

FIG. 3 is a cross-section of the closure body only, and is taken along line 33 of FIG. 1 and shows the depressions made around the circumference of the main body of the closure to insure accurate alignment of the closure cup on the mouth of the container before the threads are roll formed. 5

FIG. 4 is a plan view showing how the blanks for the closures are cut from a strip of metal, and how the material for the indicator extensions comes from the otherwise waste material between the circles.

FIG. 5 is a partial elevation in section showing the method of roll forming the threads in the closure and turning the lower edge of the indicator extension under the locking shoulder of the container.

FIG. 6 is an elevation showing the completed closure of the FIG. 1 type in position on the container mouth.

type shown in FIG. 1 has been removed from the container, and the score line has fractured during removal.

FIG. 9 is a partial cross-sectional elevation of the upper end of the closure positioned on the container mouth, and shows an alternative means for insuring alignment ofthe closure cup blank on the mouth before the pressure head reforms the top panel of the closure and the threads are rolled into the closure body.

FIG. 10 is a partial elevation showing another design of score line and slot in which the slot extends to one side only of the score line, and protruding bosses are provided to protect the fingers from the sharp edges after fracture.

FIG. 11 is a partial elevation showing another design of score line and slot, and with the metal of the closure extending down to cover the locking shoulder of the container neck at the sides between the two indicator extensions.

FIG. 12 is a partial elevation showing a preferred arrangement of score lines and slot in which there is a single slot and two score lines, and the score lines extend up toward the main body of the closure, and do not intercept the slot, thus insuring anchorage of the segment at each end after rupture of the score lines.

FIG. 13 is a partial elevation showing a modified version with three score lines and two slots, and with the same advantages.

FIG. 14 is a partial elevation showing curves slots and with the material between the indicator extensions extending down to the lower edge of the locking shoulder on the container neck, and with protective bosses formed in this material.

FIG. 15 shows the score lines in alignment with the uncut material between the ends of adjacent slots, so each segment after score line rupture is firmly anchored at each end to the main body of the closure to eliminate cut fingers, and with the indicator segments extending around the full periphery of the closure body.

FIG. 16 is a partial cross-sectional elevation showing the invention applied to a pre-threaded closure made of plastic, and indicating how the lower edge of the indicator extension is locked to the shoulder of the container neck.

FIG. 17 is an elevation ofa torquing device to be arranged in line with the automatic bottling machine for the purpose of mechanically tightening each closure to the desired torque to insure uniform unscrewing torque on all closures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS While the invention will be described in connection with certain preferred embodiments, it will be inderstood that it is not intended to limit the invention to these particular embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalent arrangements within the spirit and scope of the invention.

The present invention can be applied to a number of types of container closures already well known in the art. It is perticularly suited to the type of closure in which the container mouth is threaded and in which a cylindrical downward facing locking shoulder is provided on the container mouth just below the threaded section, and in which the closure is placed over the container mouth after filling, and threads are then formed in the closure s cylindrical body to match those of the container. This has been previously described in reference to U.S. Pat. No. 3,303,955. My invention can also be applied to pre-threaded closures of metal or plastic.

Referring now to the drawings, FIG. 1 shows an elevatiori of a closure in accordance with my invention, and in its intermediate form prior to being formed to the contour of the container mouth. The cup shaped closure body 30 is drawn from a sheet of ductile metal, preferably hard temper aluminum alloy. Cup 30 is shown in FIG. 1 positioned on the mouth of container 28, which may be made of glass or plastic. Container 28 has an outer sealing wall 33, threads 26, and downwardly facing circular locking shoulder 16 just below the threads. In these specifications, for the sake of clarity, it is assumed that the container is standing with its mouth pointing upward as in FIG. 1.

Closure body 30 comprises end panel 10 with depending cylindrical side wall consisting of upper section 11, knurled band 12, side panel 13, and wall 15. The knurled band 12 enables the user to turn the closure by hand, and optionally wall 15 can also be knurled, but it is shown plain here to simplify the drawrngs.

The tamper indicating means of the invention, which shows whether or not the closure has been opened before, comprises indicator extension 20, along with additional one or more counterparts. FIG. 1 illustrates one design of the tamper indicating extensions, others being described later in the specifications. Extension 20 is a curved continuation of the closure side wall, and has a horizontal cross slot cut through the metal at 21, and a vertical score line 22 cut part way through the metal and extending from the lower edge 19 to the region of the cross slot. The score is preferably on the inner surface to provide greater visual contrast after rupture has taken place. This line may be a series of small perforations, or a combination of perforations plus score line. A notch 23 is optionally cut at the lower end of the score line, and if desired a similar notch at the upper end. The advantages of the notches are that they start the fracture more easily by stress concentration, and also they serve to round the sharp corners, reducing tendency to cut the fingers. Raised bosses 32 are optionally pressed in the metal, and serve to hold the fingers clear of the sharp ruptured edges when the score line breaks as the closure is removed. They also help to keep the fingers from slipping with the same effect as knurling.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. l,'and shows extension 20 with score line 22 and protruding bosses 32. In the design shown in FIG. 1 there are two extension members spaced l apart around the circumference of the closure body. This is further illustrated in FIG. 7, which shows the closure in place on the container neck, and with one extension at 20 and the opposite extension at 20 The closure is preferably sealed with a polyvinyl chloride gasket having a thickness of about 0.027 inch. The gasket is shown at 29 in FIG. 1 as a flat disc which is adhesively held to top panel 10. During the sealing and threading operation, which is shown in FIG. 5, the outer rim of the gasket is drawn down to form an outer cylindrical seal against outer container shoulder 33. As shown in FIG. 1, there is a substantial space between

walls

11 and 12 and shoulder 33 when the closure cup is first positioned on the neck. The inside diameter of cup 30 must be large enough to permit it to slip freely over the outside diameter of threads 26, and when these threads are at their largest diameter in accordance with the tolerance variation in the manufacture of the bottle. Also the threads are positioned well down from the top panel. As a result it has been found that with the modern high speed bottling machines, which operate at speeds of 800 or more bottles per minute, there is a tendency for the loosely fitting cup to occasionally be tilted to one side when it is dropped on the end of the bottle. Then under this condition, when the forming head, shown at 42 in FIG. 5, comes down under high pressure, it first locks the cup in off-center position, and then re-forms the end of the closure with the gasket eccentrically positioned. The gasket is then squeezed too tightly on one outer side shoulder seal, and too loosely on the other side 180 away. I have found that this is the major reason for the large variation in unlocking torques with this type of closure.

What is required therefore is a means to insure that the space between wall 11 of the closure and wall 33 of the container, in FIG. 1, be uniform around the circumference. In my invention this is accomplished by providing a series of depressions, or indentations, as shown at 31, which are uniformly spaced around the side wall, and are just deep enough to decrease the inside diameter of the closure in the area of the container threads 26 so the closure fits snugly over the threads. There are six or more of the depressions, and they are springy to suit normal variation in thread diameter. I find that this improvement results in the closure being always positioned squarely on the end of the container and with space between

walls

11 and 33 always uniform around the circumference. The depressions are made with gradually sloping walls, so when the center wall 13 is threaded, as shown in FIG. 5, the depressions are ironed out and disappear. FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1 through the closure wall, and shows a preferred depression construction at 31. This is also shown in FIG. 1 at 27.

FIG. 4 shows how blanks for the closures are cut from a strip of ductile metal sheet, which is preferably hard temper aluminum alloy having a thickness of 0.008 to 0.010 inch. Two consecutive blanks 35 and 35' are cut from sheet 18 to

diameters

34 and 34, and with extensions 36 and 37 on one blank and 36' and 37' on the other, which extension form the indicator extensions, such as 20 in FIG. 1. The diameter at 34 is made just large enough to form the side of the closure down to point 51 in FIG. 7, which is intermediate between two adjacent extensions. It will be noted that the width of supply strip 18 has to be only slightly wider than diameter 34 by the small trim at 38 and 39, and that the projections 36 and 37 are cut from waste material between the punchings. The trim for blank 35' is shown at 38 and 39. Whereas this shows the saving if the blanks are cut from a narrow sheet of material, a like saving results if the blanks are cut from a wide sheet, as there is space between the circles for the extension projections. Cutting the extensions in this way from the waste material between the circles results in a reduction of 20 to 25 percent in the amount of sheet material required for the closure, as compared with previous complete locking band type of tamper indicators.

The sheet metal blank which is cut from flat stock as shown in FIG. 4 is next drawn into the cup form of FIG. 1. The slots in the extensions and the score lines may be cut at the same time as the flat blanks are punched out, or preferably they may be cut after the cup shape is drawn. It is desirable to cut the slots with an inclined cutting tool so the upper and lower edges of the slot do not interfere when the extension bends outward on removal of the closure.

The method of application of the closure by production bottling equipment to the mouth of the filled container is shown in FIG. 5 utilizing the improvements of my invention. Referring to FIG. 5, container 28 has end sealing surface 14, side sealing shoulder 33, threads 26, and annular locking shoulder 16. It is important that all these surfaces be smooth and formed on the container to close tolerances in order to effect a closure system that is leak proof against high pressure in the container, and at the same time one that has uniform and relatively low removal torque, and suitable for both new and recycled containers.

In FIG. 5 the closure 30 in the cup form of FIG. 1 is placed on the upper end of the container, and then pusher element 43 is pressed down on end panel 10 by rod 41, actuated by hydraulic pressure or mechanical linkage. As the closurebody is pushed down by 43 it is guided by the springy depressions 31 shown in FIG. 1, and these press snugly against the tops of threads 26, serving to guide and position top panel 10 concentrically on the end of the container regardless of the exact position of the container mouth with respect to the center-line of pusher 43. Pusher 43 comprises an end disc 43 which is vulcanized to

flexible rubber connection

40, and 40 is vulcanized to rod 41. This flexible mounting of pusher disc 43 permits 43 to move sideways with little resistance if necessary.

Pressure head 42 is now brought down while pusher 43 still maintains pressure contact on top panel 10, holding the top panel concentrically on the container mouth due to friction of the PVC gasket against end 14. The pressure head has a tapered entry surface at 46 which initially engages the outer shoulder of panel 10, which panel at this point is of the size shown dotted at 11 in FIG. 5. If the top panel isoff center relative to the tapered opening 46, due to the bottle neck not standing exactly in line, then tapered opening 46 moves the closure and neck over until they are concentrically positioned, and flexible rubber member 40 provides sufficient flexibility to permit top panel 10 and member 43 to move over sideways as required.

As a result of this arrangement, the outer diameter of the closure is re-drawn concentrically by head 42 from larger diameter 11 to new diameter 24, and the outer rim of gasket 29 is formed down to position 29, and with equal side pressure and compression of 29 around the full circumference of the closure. In systems used here-to-fore there was no way to insure concentric reforming of shoulder 11 with the result that the gasket at 29' was often over-compressed on one side and under-compressed on the other, giving a higher unscrewing torque and a less satisfactory seal. I-Iereto-fore the unguided container neck has stood up inside a loosely fitting cup closure blank without any guiding means to align the two parts concentrically while the end panel was reformed, often causing the turned down edge of the gasket to be too narrow on one side and too wide on the other.

Now while pressure head 42 in FIG. 5 maintains high pressure on the top and sides of gasket 29, the next step is to roll the threads 25 in side wall 13 to match the threads 26 on the container neck using thread roller 44.

Thread rollers are generally used in pairs to balance the pressures. Roller 45 turns the lower edge 19 of extension 20 into locking position 47 under container shoulder 16, as well as the lower edges of similar other indicator extensions around the periphery. The application of the closure is now complete, unless re-torquing is provided as described later.

The finished closure 30 is shown in FIG. 6 on container 28. The top of the closure is 10, the reduced diameter shoulder is 24, the knurled band is 12, and band may also be knurled, the thread rolled in the closure body is 25, and the indicator extension is with its turned under edge 47 locked to shoulder 16. The sloped sides of the extension are 17 and 18, and the cross slot is 21. The score line is 22, with notched entry, and protection bosses are 32.

The use of two extension members spaced equally around the circumference is the preferred design, and is shown in FIG. 7, which is a view taken at 90 from FIG. 6. One extension is shown at 20 with slot 21, and the other at 20' with slot 21 The intermediate lowest point in the main body of the closure is at 51.

I have found that closures made in accordance with my invention require a low unscrewing torque to rupture the score line, and one that is on the order of 4 inch pounds. Actually this is not generally a factor, as the highest torque is that required to start turning the closure against the friction of the seal. My tests show that when unscrewing any threaded-in-place tamperproof closure, the maximum torque and the loss of pressure take place at about one twentieth of a turn, while it takes a quarter turn to break the tamper score lines, and by this time the seal torque has almost disappeared.

FIG. 8 shows the tamper indicator extension in accordance with my invention after removal from the container, and shows the distorted position of the parts of extension 20. The bending action has separated the ruptured ends along score line 22', and the lower edges of slots 21 have tilted down, increasing the opening of the slot at points 53 and 54. Because of the strength of the material in the wide supporting

spaces

49 and 50, a considerable part of the freedom for removal of the closure extension over shoulder 16 is attained by partial straightening out of the turned-under lip 47, and the sharp fractured edges along the score line remain in alignment with each other so there is little danger of cutting the fingers when turning the closure. Bosses 32 also give added protection.

Referring to FIG. 6, it is important to understand that the dimensions and position of slot 21 can be proportioned to give efficient and sure-fire rupture along score line 22 with easy unscrewing torque for any container neck size. I have found that for the presently most commonly used bottle-neck size, which has an outside diameter of about one inch, and for the design in FIG. 1, typical dimensions of the extension indicator system are the following. The width of the extension 20 at its lower edge may be three-fourth inch; the width of slot 21 can be one-half inch and it may be positioned five thirty-seconds to three-sixteenths inch above lower edge 19 before it is bent under the shoulder. The slope of

sides

17 and 18 should be such as to make the spaces from the ends of the slot to the sloped sides each about five-sixteenth inch. This distance is substantial, and serves to give rigidity to the lower parts of extension 20, partly because of the distance from the slot to the sloped sides and partly because these surfaces are arced, which increases their stiffness. It is this stiffness that resists the lower edge at 47 from bending outward too easily, and thereby the unscrewing action places a high downward force along the two halves of the inwardly-turned lip 47 against shoulder 16. This force in turn creates high stresses along fracturable score line 22. Since the resistance to this force is greater when the score line is longer, it is desirable to reduce this length by notch 23 in FIG. 1.

FIG. 9 shows an alternative way to effect more accurate alignment between the top panel of the closure and the end of the container at the start of the closure application. A shallow 59 recess is pre-formed in top panel 60, and the outer rim is beveled at 58 around the circumference. PVC gasket disc 57 is formed to this contour when it is heat sealed to the inner surface of top panel 60. Outer wall 61 of the closure is cylindrical and large enough to slip over threads 26 of container 28. After initial placing of the closure on the container mouth, it is pushed down firmly by pusher disc 43 supported on flexible rubber mounting 40, and container end 62 naturally slides into the groove in the gasket as shown. This serves to center the end of the closure accurately on the end of the container, and to hold it positioned when the pressure head is brought down. The pressure head re-forms the inclined wall 58 to the form shown at 24 in FIG. 7. There are other advantages in providing a depression as shown in FIG. 9 or a circular groove in the top panel of the closure. One is that it provides greater radial resilience or elasticity to the top panel as compared with a flat surface, and this increases the uniformity of the side sealing pressure. It is less affected by variation in the diameter of the outside sealing shoulder of the container. The resilience also off-sets variation in the diameter of the closure top panel caused by wear of the bore in the pressure head. The depression stiffens the top panel against deflection upward from internal pressure that tends to reduce the effectiveness of the top seal. Most of these advantages can be obtained if the depression is formed in the top panel by pressing or rolling after the closure has been applied to the neck.

Recently glass containers for use with threaded-inplace closures are being made with a sharp projecting bead on the side seal shoulder as shown at 63 in FIG. 9. This bead sinks into the polyvinyl chloride gasket at the turned down rim, and improves the tightness of the seal, and with less wall pressure required. This feature combined with the concentric alignment feature of my invention substantially reduces the unscrewing torque.

FIG. 10 shows a partial elevation of another variation in which closure with threaded part 69 has an indicator extension 65, with turned under edge 64 engaging locking shoulder 16 of container 28. The slot 66 is inclined and relatively long, and is positioned to one side of score line 67, which is off-center in the extension. The upper end of the slot may extend into the cylindrical portion of the closure above the extension. Raised bosses 32 serve to protect the fingers after rupture of the score line. Notch 68 makes breaking of the score line easier, and also rounds the sharp lower corners after rupture. This design is somewhat easier to remove, requiring less torque, because of the greater length of slot to one side of the score line.

Another variation is. shown in partial elevation in FIG. 11. Closure 72 has threaded sections 71, indicator extension 75, lower edge 74 turned under locking shoulder 16 of container 28, score line 78, and double

curved slots

76 and 77. A perforation at 79 assists in rupture of the score line. Raised bosses 32 are for protection of the fingers. An alternative construction of the side wall of the closure is shown at 73, where the sides between the indicator extensions are brought down over the face of shoulder 16. This is to improve the appearance and to give added support to the sides of the indicator extensions, but it requires-more sheet material to make the closure than the previously described types.

FIG. 12 shows a partial elevation of a much preferred form of the invention. Closure 80 has threaded section 81, and indicator extension 82, which has its lower edge at 87 turned under locking shoulder 16 of container 28. There are two score lines, 83 and 85, and horizontal cross slot 84. The score lines are positioned just beyond the ends of the slot. The segment which hinges outwardly when the score lines rupture is 86. The score lines do not intersect the cross slot at their upper ends, but pass a short distance away from it at each side. Therefore, when the score lines rupture as the closure is removed, the segment remains firmly anchored along its upper edge to the main body of the closure, held by the narrow metal strips at each end between the slot and the scores. Since the upper edge of the segment remains attached at each end to the closure body, there is no possibility of cutting the fingers along this edge.

A variation of this form is shown in partial elevation in FIG. 13. Closure 90 has threaded section 91, and indicator extension 92 with its lower edge turned under at 93 in locking engagement with shoulder 16 of container 28. There are three

score lines

94, 95, and 96, and two

horizontal slots

97 and 98, so positioned that the score lines do not intersect the slots. The segments between the score lines are 99 and 100. When the closure is unscrewed, the score lines rupture, and the two segments hinge outward. The upper edges of each seg ment remain firmly anchored at each end to the main body of the closure. The segments in this arrangement are not as wide as those previously shown. Bosses 32 serve to provide added protection against cutting the fingers. These projecting bosses can be applied to any of the indicator designs, including FIG. 15. Whereas they are shown as circular, they may be bulges of any shape, such as rectangular ridges paralleling the score lines. 1

The various designs of indicator extensions illustrated in FIGS. 1, 6, 10, 11, 12, and 13 can be used in various multiples per closure. Use of two extensions per closure is the most economical on material usage. Three extensions work well and save material. Four or five extensions can also be used if desired. Actually the use of only two or three indicator extensions applies principally to the most common size of screw cap closure which is used almost universally, and in which the outside diameter of the locking shoulder 16 is one and one eighth inches. The invention is also applicable to larger sizes of container mouths, which may require a larger number of extensions.

Where a more or less continuous series of indicators is desired around the circumference, the advantages of my invention can be obtained by going to the arrangements shown in FIG. 14 and FIG. 15.

FIG. 14 shows another variation of the tamper indicator system. Container closure 101 with threaded section 102, has a number of indicator extension segments around the periphery, such as 103 and 108. Segment 103 is bordered at its ends by

score lines

104 and 105 and above by curved slot 106, and its lower edge is turned under locking shoulder 16 of container 28 at 107. Segment 108 is bordered by

score lines

109 and 110, and curved slot 111 above, and is locked under shoulder 16 at 112. The segments are spaced by sections of the closures cylindrical body which extend down to the lower edge of the locking shoulder, such as 113 and 114 in the drawing. These sections, which do not hinge out when the closure is removed, preferably have bosses 32 to protect the fingers. The arrangement shown in FIG. 14 has four segments that hinge out when the closure is unscrewed, and four intermediate spacer sections.

FIG. 15 shows a partial elevation of the invention applied to the arrangement wherein the indicator extensions extend in a continuous series around the periphery of the closure. In FIG. 15, closure has threaded-in-place section 121, and below the threads is a line of

horizontal cross slots

130, 131, and 132. The slots extend completely around the closure body and the spaces between the ends of adjacent slots are about 1/8 inch wide. Vertical score lines, as shown at 123, 125, 127, and 129, extend from the lower edge of the closure to the line'of the slots, or even slightly above. The score lines also extend around the periphery, and each score line is lined up with the uncut material between the slot ends, preferably at the mid-point. The score lines and slots define

segments

122, 124, and 126, and others around the periphery. The segments have their lower edges turned under locking shoulder 16 of container 28 as at 128. The lower ends of the score lines may be notched to make rupture easier, and to eliminate sharp corners. When the closure is removed, the score lines rupture, breaking in tension, and the segments bend outward and remain firmly anchored at each upper end. Raised bosses can be provided, such as shown at 32 in FIG. 14, and optionally there can be perforations above the scores as at 79 in FIG. 11.

FIG. 15 shows the proportions when there are eight segments around the periphery. Six or eight is the preferred number. It is important to note that on unscrewing, each segment hinges on the attachments to the closure body at its extreme ends, and because the slot is an arc, the upper and lower surfaces of the slot tend to come together. The slot must therefore have its upper and lower edges spaced well apart, or be curved as in FIG. 14, or be cut with an inclined tool. The width of the metal between the ends of adjacent slots should be 0.10 to 0.125 inch, half of which goes to support the segment on one side and half to the other side, if the score bisects the space. These attachments protect the fingers from the sharpness of the ruptured score lines at the upper ends. Because each segment has the same attachment at the top as the adjoining segment, all the segments hinge out the sameamount, and this keeps the lower corners in line with each other so they will not cut the fingers, especially if the corners are rounded, as by notching as shown at 23 in FIG. 1. In order to permit the segments to hinge out freely, it is essential that there be no bridge connections within the tion cork, serving to give added cushion. This is advisable because the threads do not fit as well as when they are rolled in at assembly, and also there is only one seal between the gasket and the end surface 150 of the container. A knurled band is at 142, and threads 143 in the closure match those on the container mouth at 144. The tamper indicator extension is 147, the cross slot is 145, and the score lines 146 is shown dotted. The arrangement of the slot and score line may be similar to those previously described in various designs for the ductile metal closure. The lower edge 148 of the extension is beveled in the back so it can be slipped over the container mouth when first applied, the extensions deflecting outward as necessary, but without straining the score lines. When the lower edge reaches the lower locking face of container shoulder 16, it snaps into the position shown. The container may have a supplementary annular shoulder shown dotted at 152 to protect edge 148 so it can not be pried up by anyone trying to tamper with the contents. The container is shown as made of plastic, but it may be glass or other material.

.It is very difficult even with the closure application method illustrated in FIG. 5, and described in the specifications, to attain a uniform unscrewing torque under the varying conditions encountered in bottling plants. The system described for insuring a concentric gasket and concentric re-forming of the top shoulder of the closure eliminates one principle cause of torque variation. Other adverse factors are wear of the pressure head re-forming bore, wear of the thread rollers, and container dimensions not within specifications. Added to this is the large variation in the strength of the fingers of the user, which dictates a lower unscrewing torque than hereto-fore attainable. Commercial tolerances run 4 to 17 pound inches, yet anything over 6 inch pounds is difficult to unscrew without a tool.

In order to produce a more nearly perfect closure application in accordance with my invention, a torquing machine is positioned in the bottling line following the closure application and sealing operation. The torquing unit may have multiple heads in order to operate at high speed, and with the container conveyor traveling in an arc around the unit so several containers can be torqued simultaneously. FIG. 17 shows a single torquing head to illustrate the principle of operation, and which is readily adaptable to a multiple unit by providing several heads on the common rotary mounting. Referring to the drawing, container 28 has been sealed with closure 160, which has tamper indicator 158, and upper knurled band 159. The container is carried past the unit by an extension of the same conveyor used to take it through the bottling machine, and which may be as shown, comprising carrier cup 161 on wheels 162 traveling on rails 163, and drawn by guided chain 182.

A rubber faced back-up element 170 is mounted on bracket 183, which is attached to sleeve 166 on support column 165. The vertical column 165 is arranged to turn in base 164, and driven by sprocket 183, which is connected to the main conveyor driving unit. When it is time to torque a closure, the container is locked against rotation by applying air pressure to cylinder 168, causing rod 169 to press rubber faced block 167 against the container wall, which is backed up by 170. The upper elements are mounted on arm 171. A yoke 173 is supported on pin 177, which can move up and down in guide member 172. At the lower end of 173 is head 178, attached by flexible rubber connection 179, and having a serrated bore on its under side that fits over the knurled band of the closure to hold it securely for the application of torque. The flexible connection prevents any strain on the closure.

As the container advances on the conveyor, the whole upper torquing assembly rotates with vertical column 165, and the level of member 173 is determined by its supporting roller 174, which rides on a circular track 175. At the torquing point, there is a depression in the track, as shown dotted at 176, and when the depression is reached it cams the assembly down, positioning head 178 on the closure, and gripping it by the knurled band.

A torque can now be exerted on the closure by applying air pressure to air cylinder 179, which is supported on clevis 180, and is connected to yoke 173 by piston rod 181 and clevis 182. The pressure of the air can be regulated to apply any desired torque to the closure. The container clamping mechanism in FIG. 17 is shown in the closed position. In the actual design, to facilitate entry of the container into the space between back-up 1'70 and the pusher 167, these units may be arranged to grip the sides of the container at from the way it is shown.

Alternatively, a torquing means can be incorporated in each of the multiple heads of the closure sealing unit, such as shown in FIG. 5. To accomplish this a clamp is provided to keep the container from turning, the pressure head is raised slightly after the threads are rolled and just enough to take the pressure off the end and side seals, the pressure head will have a serrated bore to engage the upper knurled band, and then the torquing effort will be provided by slightly rotating the pressure head under the required inch pounds of torquing force. The tamper extension lower edge can be turned under before or after the torquing.

The torquing device can be used in either one of two ways. All closures can be torqued in the tightening direction, thereby insuring a minimum degree of tightness, and only the less tight closures will be turned slightly. The other and preferred system is to first apply a torque in the unscrewing direction to release each closure slightly, and then to re-torque to the desired degree of tightness. This insures that each closure will require the same desired unscrewing torque, and is the only way to accomplish exact uniformity, and thereby to bring the opening torque down to an acceptable level of about 3 to 6 inch pounds. As previously pointed out, it requires very little arc or turning to loosen the closure seal, and this small amount of rotation does not approach the point where the score lines are affected.

In the claims that follow it is assumed that the container is standing with its mouth pointing upward. Reference to score line indicates the preferred means for decreasing the strength of a line of the material by cutting a groove about half way of more through it, and preferably on the inside surface. Other means such as perforations or score line plus perforations are considered optional. The cross slots are substantially horizontal, but may be slightly inclined, may project up into the main body of the closure, or may be curved a small amount without departing from the claims. The slots are preferably cut with an inclined tool, as shown at 21 in FIG. 5, as this reduces the chance of the edges coming together to resist hinging up of the segment.

In the claims the definition of the word score line is a weakened line in the material of the closure which is rupturable byreason of the weakening, and the weakened line may comprise a line where the material is thinner by reason of a score line groove on either side of the material or on both sides, or the weakened line may be due to perforations in the material, or it may be a combination of score line groove plus perforations. In the claims it is understood that a narrow band of knurling is preferably provided around the periphery of the cylindrical body of the closure just above the threaded section, and optionally a second knurled band just below the threaded section, to facilitate turning the closure by hand. v

It will be apparent that while I have shown and described the invention in several preferred forms, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

What I claim is:

l. A tamper indicating container closure made of thin ductile metal, of the type which embodies fracturable indicator means to show whether the closure has been removed subsequent to the initial application of the closure to the container, for use on containers of the type which has a threaded mouth end and has a downwardly facing locking shoulder abutment extending around the periphery of the container neck and positioned below the threaded section and which comprises means to actuate said indicator means as the closure is unscrewed, said closure comprising a top panel with depending cylindrical body, a threaded section in said cylindrical body to match the threads of said container mouth end, the improvement comprising;

a plurality of arc shaped segmental indicator members formed as integral individual downward extensions of said cylindrical body, the lower edges of said indicator members being turned under said container locking shoulder at initial application of the closure to secure a hold on said shoulder, each said indicator member having a substantially vertical weakening score line formed therein, said score line extending from the lower edge of said indicator member to the region just below said threaded section, and whereby unscrewing of said closure causes rupture along said score line to provide visual indicator means to show that such closure removal has taken place.

2. A tamper indicating container closure as defined in claim I, in which there is a substantially horizontal slot cut through the metal of said closure and located in a position just above each said score line, and such that said score line, or a line drawn as an upward extension of said score line, intersects said slot, and there being a separate slot for each score line.

3. A tamper indicating container closure as defined in claim 1, in which there are two substantially horizontal slots cut through the metal of said closure for each of said score lines, and with said slots located at a level in the region of the upper end of said score line, and with an uncut space between the ends of said slots, and such that said score line, or a line drawn as an upward extension of said score line, meets said uncut space and does not intersect either of said slots.

4. A tamper indicating container closure as defined in claim 1, in which there is a plurality of substantially vertical weakening score lines formed in each of said indicator member extensions, and with each of said score lines being formed as defined in claim 17, and there being a substantial lateral space between adjacent score lines.

5. A tamper indicating container closure as defined in claim 4, in which a plurality of said indicator member extensions each has only two score lines, and in which there is a substantially horizontal individual slot cut through the metal of said closure and positioned at a level in the region of the upper ends of two adjacent score lines, and above the segmental space between said two score lines, and having a length that is shorter than the space between said score lines, and such that said slot is not intersected by either of said score lines, or by a line drawn as an upward extension of either said score line.

6. A tamper indicating container closure as defined in claim 4, in which there are substantially horizontal slots cut through the metal of said closure in a plurality of said indicator member extensions, each said slot being positioned at a level in the region of the upper ends of two adjacent score lines, said slot having a length that is shorter than the distance between said adjacent score lines, and such that said slot is not intersected by either of said score lines, or by a line drawn as an upward extension of either said score line, and said slot lying above the space between said score lines.

7. A tamper indicating container closure made of thin ductile metal, of the type which embodies fracturable indicator means to show whether the closure has been removed subsequent to the initial application of the closure to the container, for use on containers of the type which has a threaded mouth end and has a downwardly facing locking shoulder abutment extending around the periphery of the container neck and positioned below the threaded section and which comprises means to actuate said indicator means as the do sure is unscrewed, said closure comprising a top panel with depending cylindrical body, a threaded section in said cylindrical body to match the threads of said container mouth end, the improvement comprising;

a continuous cylindrical integral member extending below said threaded section, formed circumferentially around the body of said closure, and divided into a plurality of rectangular segments, each seg ment being defined by a substantially vertical score line at each end, said score line extending from the lower edge of each said segment up to the region just below said threaded section, and each segment having its lower edge turned under said locking shoulder at initial application of said closure to secure a hold on said shoulder, and whereby unscrewing of said closure causes rupture along said score lines, providing visual indicator means to show that such closure removal has taken place. 8. A tamper indicating container closure as defined in claim 7, wherein there is a substantially horizontal slot cut through the metal of said closure and extending along the upper border of each of a plurality of said rectangular segments, each said slot having a length that is shorter than the distance between said score lines, such that said slot is not intersected by either of said score lines, or by a line drawn as an upward extension of either of said score lines.

9. A tamper indicating container closure as defined in claim 8, wherein the length and lateral position of each said slot in said closure is such that each end of said slot is no closer to the score line adjacent that end than a distance of 0.04 inch.

10. A tamper indicating container closure as defined in claim 7, wherein the threads in said cylindrical body of said closure are roll formed during the initial application of said closure to said container with the closure blank in position on said container mouth end, and providing means to match the threads formed in said closure with those in said mouth end.

11. A tamper indicating container closure as defined in claim 7, wherein the said thin ductile metal is hard temper aluminum alloy having a thickness between 0.007 and 0.010 inch.

12. A tamper indicating container closure as defined in claim 7 in which there are outwardly protruding bulges in the metal of the closure, said bulges positioned near the sides of a plurality of said score lines, and comprising protective means to prevent injury by cutting from the sharp ruptured edges along said score lines after said closure has been opened.

13. A tamper indicating container closure as defined in claim 7, in which there are notches in the lower edge of the material of said segments, said notches being located at the lower ends of said score lines.

14. A tamper indicating container closure as defined in claim 10, wherein there is a concentric circular depression in said top panel of said closure, and said depression having an outer diameter on the underside which is slightly smaller than the inner bore of said container mouth end, and providing guidance means for holding said top panel in concentric alignment on said container mouth end during the top sealing and thread rolling operations.

Claims

1. A tamper indicating conTainer closure made of thin ductile metal, of the type which embodies fracturable indicator means to show whether the closure has been removed subsequent to the initial application of the closure to the container, for use on containers of the type which has a threaded mouth end and has a downwardly facing locking shoulder abutment extending around the periphery of the container neck and positioned below the threaded section and which comprises means to actuate said indicator means as the closure is unscrewed, said closure comprising a top panel with depending cylindrical body, a threaded section in said cylindrical body to match the threads of said container mouth end, the improvement comprising; a plurality of arc shaped segmental indicator members formed as integral individual downward extensions of said cylindrical body, the lower edges of said indicator members being turned under said container locking shoulder at initial application of the closure to secure a hold on said shoulder, each said indicator member having a substantially vertical weakening score line formed therein, said score line extending from the lower edge of said indicator member to the region just below said threaded section, and whereby unscrewing of said closure causes rupture along said score line to provide visual indicator means to show that such closure removal has taken place.

2. A tamper indicating container closure as defined in claim 1, in which there is a substantially horizontal slot cut through the metal of said closure and located in a position just above each said score line, and such that said score line, or a line drawn as an upward extension of said score line, intersects said slot, and there being a separate slot for each score line.

7. A tamper indicating container closure made of thin ductile metal, of the type which embodies fracturable indicator means to show whether the closure has been removed subsequent to the initial application of the closurE to the container, for use on containers of the type which has a threaded mouth end and has a downwardly facing locking shoulder abutment extending around the periphery of the container neck and positioned below the threaded section and which comprises means to actuate said indicator means as the closure is unscrewed, said closure comprising a top panel with depending cylindrical body, a threaded section in said cylindrical body to match the threads of said container mouth end, the improvement comprising; a continuous cylindrical integral member extending below said threaded section, formed circumferentially around the body of said closure, and divided into a plurality of rectangular segments, each segment being defined by a substantially vertical score line at each end, said score line extending from the lower edge of each said segment up to the region just below said threaded section, and each segment having its lower edge turned under said locking shoulder at initial application of said closure to secure a hold on said shoulder, and whereby unscrewing of said closure causes rupture along said score lines, providing visual indicator means to show that such closure removal has taken place.

8. A tamper indicating container closure as defined in claim 7, wherein there is a substantially horizontal slot cut through the metal of said closure and extending along the upper border of each of a plurality of said rectangular segments, each said slot having a length that is shorter than the distance between said score lines, such that said slot is not intersected by either of said score lines, or by a line drawn as an upward extension of either of said score lines.