SAFETY CLOSURE FOR CONTAINERS

Abstract: A safety closure for containers comprises an assembled combination of an inner cap (103) housed in and surrounded by an outer cap (102). The inner cap (103) is provided along its outer circumferential surface or skirt portion (104) with a series of first teeth (106), the inner depending skirt portion of the outer cap (102) is provided with a series of second teeth (107) which can be brough in engagement with the first said teeth (106) by means of a relative coaxial movement of the inner and outer caps. The safety closure can be unscrewed from the container or screwed upon the mouth of the container respectively only by exerting upon the outer cap (102) a downward pressure causing the said teeth (106 and 107) to become interengaged, whereafter the inner cap (103) can be turned. The downward pressure upon the outer cap is resiliently resisted by means of spring elements or lips (118) depending from the upper wall portion (113) of the outer cap (102) which lips (118) are flexing against a wall portion (110) of the inner cap (103) which is located inside the container mouth and which converges annularly. The inner cap (103) is provided with a central cylindrical portion (111) rising up from said annulus (114), said lips (118) being operable in the space between the said cylindrical portion (111) and the inner mouth portion of the inner cap. Said central upper surface (112) of the inner cap (103) being rigidly and integrally connected to the remaining inner cap portion (110) in such a manner as to resist weight loads placed upon the safety closure even if the outer cap surface (113), surrounding the said central portion (112) may be slightly depressed thereby. The surface of said central cylindrical portion (111) being shaped as a central guide to the surrounding edge portion of the outer cap (102) during its coxial movement if downward pressure is exerted. It is preferred to have the surfaces of the upper portions (112, 113) of the inner and outer caps (103, 102) lying in nearly the same horizontal plane to render the safety closure a one piece outlook.

Description: -ι- Safety closure for containers This invention relates to safety closures for containers which can be readily applied and removed by one having knowledge of their operation, an which are relatively safe in the hands of children because they are usual¬ ly unable to manipulate the closures in the required manner to remove them from the containers. Broadly stated, the closure described herein comprises inner and oute caps with tee,th formed on the skirts of the caps for turning and applying the inner cap on the container when torque is applied to the outer cap in the application direction. When t-he outer cap is turned in the removal di¬ rection, however, the theeth on the respective caps are not engaged so that the inner cap will not be turned. To remove the closure from the con¬ tainer, it is necessary to exert sufficient downward force on the closure so that horizontally and radially extending teeth on the outer cap are brought into engagement with cooperating teeth on the inner cap and, when a torque is simultaneously applied in the removal direction, the inner cap will than be turned for removal from the container. Closures of these kind . should be as fool proof as possible and not open when children rotate the outer cap relative to the inner cap without the accompanying simultaneous downward thrust to engage the teeth on the ends of the inner and outer caps Safety closures of the described type have been in use for drug con¬ tainers but in view of stringent government product safety regulations are increasingly desirable for containers closures containing more or less agressive liquids dangerous to children. In every normal household such containers or bottles frequently appear and are to be opened and closed many times more than is the case with drug containers. The latter moreover are mostly less easily reachable for children and usually are kept away more safely. Usually plastic bottles contain aggressive liquids, such as e.g. chlo¬ rine bleaching water. Production methods for such bottles cannot avoid the ' irregularities around the neck opening of these bottles, thereby creating sometimes serious difficulties because of liquid crystallization as a re¬ sult of leakage. If the space between an inner and outer cap of an existing safety closure would be filled with crystals, the safety aspect of the clo¬ sure would be endangered as this could unexpectedly cause an engagement between the teeth on the skirts of the caps, enabling unauthorized removal thereof. -2- It is furthermore preferred that the ratching of the cooperating teeth is not just felt or heard while turning the outer cap around the inner cap in order not to invite the unaware and unauthorized user of the bottle closure to unscrew the safety closure occasionally in the required manne . In view to the applicability of the safety closure to plastic bottles or the like which always show unavoidable irregular sealing rims at the bottle opening due to the production processes, it is an object of the present invention to provide a safety closure of the general foregoing kind which is compatible with many existing kinds of irregularly shaped bottle rims yet providing an efficient sealing of the bottle.by the availa¬ bility of predetermined additional sealing forces cooperating with the essential parts of the neck portion of the bottle. Other objects and advantages will become apparent from the following detailed description, while referring to the attached drawings, in which: Fig. 1 is an enlarged, perspective view of a safety closure embodying tne novel features of the present invention; Fig. 2 is a bottom view of the outer cap with portions cut away and with the inner cap removed; Fig- 3 is a cross-sectional view taken generally along the line 3-3 of Fig. 1; the left part showing the safety closure in its normal position while no removal force or torque is applied, the right part showing the safety closure while exerting a downward pressure upon the outer cap in the direction of the arrow; Fig. 4 shows another embodiment of the invention in a cross-sectional view similar to Fig. 3. The inner cap and the outer cap are modified; Fig. 5 shows still another embodiment of the safety closure of the present invention, also in a cross-sectional view similar to Fig. 4; Fig. 6 and Fig. 7 show partially a bottom view and a top view of the outer cap shown in Fig. _ in its asse hled positio (s). (The scale of the various embodiments shown.may differ for purposes of clarification only) Turning now to the drawings, Fig. 1, 2 and 3, there is shown a safety closure 1 eabodying the present invention and comprising an outer cap, indicated generally at 2, overlying an inner cap, indicated generally OMPI -3- at 3, with the inner and outer caps being concentrically aligned. To fasten the safety closure 1 to a container (not shown), a generally cylin¬ drical skirt 4 of the inner cap 3 is formed with a container fastening means such as a spiral screw thread 5. To apply the safety closure 1 by screwing the thread 5 onto the cooperati¬ vely threaded portion of a container, one or more ratchet teeth, indicated generally at 6, on the skirt portion 4 of the inner cap 3 project radially and generally coaxially outwardly for engagement with one or more ratchet teeth, indicated generally at 7, on the inner side of a depending general¬ ly cylindrically shaped skirt position 8 of the outer cap 2. The coopera¬ ting teeth 6 and 7 are shown in a vertical position. However they may in¬ stead also be placed in a generally sloping position under say 45 °. The upper portion of the inner cap 3 is further shaped in such a manner that an upper container rim is received in the circumferential space 9 created by the skirt portion 4 being turned back in itself at 10. The central upper portion 11 of the inner cap 3 is of cylindrical shape and its flat top surface 12 lies nearly in the same plane as the concentrically arrang¬ ed top surface portion 13 of the outer cap 2. The annular connecting por- its ■ ' tion 14 of the inner cap 3 between/skirt portion at 10 and its cylindrical top surface 12 will perfectly house and thereby seal any irregularity pro¬ cessed on the container neck portion to be located in the space 9, thereby avoiding any possible leakage of liquid from the container. The lower depending skirt portion on the outer cap 2 is provided with a cut b ack cylindrical portion 15 which narrows to the bottom part into a thicker annular retaining portion 16. The inner cap 3 is further provi¬ ded at its lower part with an annular protruding rim 17 which, in the assembled position of both caps 2 and 3 of the safety closure 1, is retain¬ ed within annular portion 16 thereby enabling the coaxial movement of the depending skirt portion 15 with respect to the inner cap 3. Furthermore the outer cap 2 continues from its horizontal flat top surface 13, which surrounds the top surface of the inner cap 3 concentrically, into one or more, but preferably six depending diverging flexible segments 18 or resi¬ lient lips 18, the bottom ends of which normally rest upon the horizontal annulus 19 of the inner cap 3 as shown in Fig. 3. The function of these segments 18 will easily be understood. In the position of the safety clo¬ sure 1 shown in the left part of Fig. 3, the inner cap 3 will be sealingly -4- engaged with the container opening, the outer cap 2 by means of its springy diverging lips 18 is held in its uppermost position wherein the topmost portion of.both the inner and the outer caps 3 and 2 respectively lie in the same horizontal plane. A removal torque only, exerted on the outer cap 2 will not result in unscrewing the inner cap 3 from the con¬ tainer since none of the teeth 6 and 7 will engage. At the right in Fig. 3 it is shown that the resilient lips 18 are pressed down only upon the exertion of a downward pressure indicated by the arrow. Only than the teeth 6 and 7 may become interengaged and when simultaneously a removal torque is applied to the outer cap 2, the safety closure can be unscrewed from the container. It is very important in view to the durability of the desired function of a safety closure of the type herein described, that there will be no per- manent downward pressure to be exerted on the outer cap 2 which may per¬ haps cause damage to the segments or lips 18 to become so much overloaded that they finally collapse due to material fatigue of the plastic material thus losing its function as a safety closure entirely. By making the cen¬ tral portion, of the inner cap 3 high enough and by giving it sufficient material strengh , it will.e.g. be possible that a number of layers of containers can be stored above a first layer, e.g. in a box, or if packed in plastic shrinking foils, each layer being placed upon a horizontal sepa¬ rating sheet. Even such a way of container packing does never interfere with the desired function of the safety closure because no downward pres- sure is permanently during storage exerted upon the outer cap 2 by the weight of any other container or the load of other articles placed thereupon. There remains a slight clearance between circumferential edge of the flat central portion 13 of the inner cap 3 and the adjacent portion 13 of the outer cap 2, serving to avoid possible dirt penetrating the workable parts of the safety closure 1. The invented closure does not really allow for leakage of liquid because of the specially designed sealing portion on the inner cap effectively housing the container opening and if unexpected¬ ly any liquid would become enclosed and received in the annular gutter por- tion at 14, crystallization would not prevent the normal operation of the safety closure. To avoid the penetration of dirt and liquid to become trap¬ ped between the inner and outer cap portions, it is also possible to let -o the circumferential horizontal edge of the central portion 12 slightly o- verlap or overly the adjacent surrounding outer cap portion by a thin wal¬ led flexible radial extension, resilient enough to be slipped through the central opening in the outer cap 2 and spring back in its original position after assembling the inner and outer caps 2 and 3 respectively to become the safety closure 1. It is likewise possible to locate the uppermost portion of the inner cap 3 under an integral cover portion forming an integral extension to the upper surface of the outer cap 2. The safety closure may than be opened only after e.g. tearing off the covered part of its central portion where¬ after the desired safety function can be performed. In Fig. 4 at left and at right respectively the unoperational and the operational position of another safety closure is demonstrated in a cross- sectional view. The outer cap 102 houses the inner cap 103 which skirt por- tion 104 is provided with an internal threaded portion 105. The upper skirt portion 104 tapers and is externally provided with radially extending teeth segments 106 and other teeth 107 are formed on the inner wall portion 108 of the outer cap 102. The usual container rim of the opening portion of the container (not shown) is located in the space 109 after the closure 101 is screwed upon the container, the wall portion 110 converging into an annular connecting portion 114 forming the bottom part of the cylindrical central . portion 111 on the inner cap 103 which ends in the upper wall portion 112. At its inside, the outer cap 102 is integrally formed with a number of six separately disposed depending resilient lips 118 which are integrally for- med with its surface portion 113. Contrary to the resilient lips in the em¬ bodiment of the safety closure as shown in Fig. 3, now the lips 118 have a substantial length strength tending to resist with their lowermost ends inwardly directed radial forces. Exerting a downwardly di¬ rected pressure, shown by an arrow , upon the outer cap 102, the lowermost ends of the lips llδare forced along the annular surface of the converging portion 110 downward and against the cylindrical wall portion 111, thereby causing engagement of the teeth 107 and the teeth 106. A removal torque ap¬ plied to the outer cap 102 will than cause the inner cap 103 to unscrew from the container. For screwing the inner cap upon the container, it will be clear that the same operation, followed by an onscrewing torque will re¬ sult finally in the back movement of the outer cap 102, by means of the resilient lips 118, into its position shown in the left of Fig. 4. It will be clear that the stiffness of these lips 118 is such greater than is de- sired for the lips 18, because the forces for relifting the outer cap 102 from its depressed position back into its normal position, must be derived from the reactive forces against the converging wall portion 110 caused by the lowermost ends of the lips 118. As a result of the relatively strong forces which are created by the cooperation between and along the lips 118 and the abutting wall portion 110, possible liquid crystals which may have been enclosed in the annular cavity are broken down or crushed by the re¬ peated operation of opening the container by first pressing down the outer cap 102. In this specific embodiment of the invention there is also shown an additional central cover disc 120 overlying the central portion 112 as it may have a kind of guarantee function to verify that the container has not yet been opened by unscrewing the safety closure from it. The cover disc 120 is connected to the outer cap 102 by means of e.g. three tearable ribbs 121 , integrally formed with the cap. The wall portions of the inner cap 103 which are located at the inside of the container opening are conically shaped in . -such a way as to guide and seal off the opening of the container perfectly, even if irregularities would appear as a result from the production method used. The cap 102 is centrally guided by the cylindrical wall portion 111. . Fig 5 discloses a similar safety closure as just described, however with few differences. The mouth of the container is somewhat wider and the central cylindrical wall portion 211 is integrally connected to a conical lower wall portion before it continuous into the connecting annular portion 214. To assist the assembling of the inner cap 203 within the outer cap 202, a conical ring portion 222 is integrally formed with the outer cap 202 to ensure the correct position of the uppermost central portion 212 of the in¬ ner cap 203 with respect to the outer cap 202. The cooperating teeth 206 and 207 respectively, the retaining ring portion 216 and the protruding rim portion 217 are accordingly shown. In Figs. 6 and 7 the position of some parts with respect to the outer cap 102 of Fig. 4 are additionally shown in sofar as the cross-sectional view does not always sufficiently disclose their location. The safety closure according to the present invention is preferably molded from relatively hard non-yielding plastic materials, such as polypro- pylene, polyethylene or the like, depending on the various requirements relating to the container, the liquid and the duration of expected contai¬ ner use and the desired opening and closing forces to be applied by the average user of a container for household purposes.

Claims: Various features of the invention are seth forth in the ollowing claims . What is claimed is: 1. A safety closure for fastening to containers, comprising: an outer cap having a circular top end wall and a cylindrical shaped skirt depending from the outer edge of said top end wall, an inner cap having a top end wall and a depending skirt joined to the outer edge of said end wall, said outer cap overlying the lower inner cap portions and being concentric there¬ with, container fastening means on the skirt of the inner cap for releas- ably fastening on a portion of a container, radially and vertically exten- ding teeth on the external wall surface of the inner cap and interengage- ' . able therewith and vertically extending teeth on the inner wall of said outer cap skirt, a central portion on said inner wall of said outer cap, a central portion on said inner cap engaging said central portion of said outer cap and spacing in a vertical direction said radially extending teeth of said caps from each other, a downward force on said outer cap en¬ gaging said" radially extending teeth on said inner and outer caps so that a simultaneously applied torque on the outer cap in the removal direction will act through said radially .and vertically extending teeth to turn said- inner cap to release the same from the container or to screw the same upon the container respectively on said skirt on said outer cap a number of resilient depending spring elements or integral lips being formed resting against wall portions of the inner cap to assure that said inner cap re¬ mains stationary when a removal or application torque is applied to said outer cap, said lips tending to keep said teeth on the outer and inner caps elastically out of engagement by means of spring contact between the ends of said lips and wall portions on the inner cap, said cap having a recessed circumferential vertical inner space allowing for vertical move¬ ment of a circumferential retaining rib on the inner cap to keep the inner and outer caps in their assembled position. 2. A closure as defined in claim 1 wherein each of said lips surrounds said central opening in the outer cap, said central opening providing for guidance of the outer cap along the circum erential outer wall portion of the inner cap protruding through said opening when a downward force is -8- exerted on the outer cap causing the lips temporarily to flex radially and outwardly away from the central opening, each of said lips forming part of seperate con ical wall portions diverging inwardly from the central opening on the outer cap. 3. A closure as defined in claim 1 wherein each of said lips is de¬ pending from the top wall portion of the outer cap halfway between its de¬ pending skirt portion and its central opening, each of said lips extending substantially vertically downward until its lowermost end is in touch with a conical annular wall portion of the inner cap, located underneath the space portion on the inner cap housing the container mouth, said conical wall portion causing said lips to resist a downward pressure, said central opening in the outer cap closely fitting the correspondingly shaped central circular wall portion of said inner cap, said circular wall portion lying in the same horizontal plane as the central top surface of the outer cap. 4. A closure as defined in claim 3, wherein each lip has a length which.corresponds to the total depth of the annular cavity around the cylindrical wall portion of the inner cap, the ends of said lip having such a material strenght that liquid crystals will be broken down and crushed by the downward movement of the outer cap. 5. A safety closure as defined in claim 1 wherein said central port¬ ion on said inner cap integrally constitutes a self supporting loading surface on top of the safety closure, able to resist a specific long las¬ ting substantial weight load and thereby not simultaneously causing parti¬ al or permanent damage to the safety function of said lips, this central portion on said inner cap being positioned in such a manner as to ly in nearly the same level of surface as is assumed by the uppermost portion of the outer cap surrounding said central portion in the position when the outer cap is not operated.

Inventors: BEKKERS HENRICUS ANTONIUS MARI, BEKKERS HENRICUS ANTONIUS MARIA
Applicants: BEKKERS HENRICUS ANTONIUS MARI, TECHNOPLAST BV, BEKKERS HENRICUS ANTONIUS MARIA
Application year: 1982
Main classification: B65D55
IPC codes: B65D50