The present invention relates in general to plastic plugs that are constructed and arranged to assemble into a container opening, typically by threading. More specifically, the present invention relates to the described style of plastic plug that receives an overcap. Preferably the overcap is constructed and arranged to assemble to the plastic plug and/or container with a tamper-evident configuration and function. In the preferred embodiment the plastic plug is a unitary, molded component and the overcap is a unitary, molded plastic component. These two components are pre-assembled prior to plug insertion into the container opening without any overcap connection to the container. One variation, as disclosed herein, is to replace the plastic overcap with a heat-weld foil disk for covering over the plug.
When designing a closure or closure assembly that preferably includes a tamper-evident configuration or construction, it is important to consider the overall design efficiency, the reliability of the component parts as assembled and as installed, the overall cost, the physical size and the overall aesthetics, to mention some of the relevant considerations. Reliability includes not only how the tamper-evident construction functions in terms of properly revealing when a tampering attempt has been made, but also in not prematurely failing or showing a tampering attempt when none was made.
In one prior art construction, the tamper-evident component is a plastic cover that includes a skirt that cooperates with ratchet projections on an outer surface of the container opening. The size and shape complexity of this tamper-evident component adds to the component cost. The plastic plug threads into the neck opening of the container and then the tamper-evident component is engaged on the container.
In another prior art construction the tamper-evident component is of a part-metal construction in combination with a plastic overcap so that the plastic skirt of the overcap can be crimped around a cooperating form on the outer surface of the container neck opening, after the plastic plug is threaded into the neck opening of the container. This tamper-evident component, similar to the first-described prior art component, is a more costly component that requires a specific style of container due to the structural cooperation between the tamper-evident overcap and the container.
In contrast to these prior art examples, the tamper-evident overcap described herein as one embodiment of the present invention provides a simpler design that engages only the plug providing greater versatility since the container style does not have to be selected to cooperate with a particular style of tamper-evident overcap. While the plastic plug construction that is part of the prior art and depicted by the present invention includes interior structural features or forms for facilitating the threading of the plug into the container neck opening, the present invention does not use those features for the initial assembly of the plug and overcap combination into the container neck opening. Instead, according to one embodiment of the present invention the tamper-evident overcap is preassembled to the plastic plug and the plug features (interior) that might otherwise be used for tightening the plastic plug into the neck opening are covered by the tamper-evident overcap. In another embodiment of the present invention, a heat-weld foil disk is used to close off the interior structural features of the plug. These assembly constructions thus require a different method of installation and different tooling, both of which are described herein and both of which constitute an important part of this overall invention.
The present invention provides a simple and reliable and aesthetically-pleasing, low cost tamper-evident overcap that quickly assembles to the plastic plug. The overcap does not interface with the container neck opening thereby allowing a wider range of container neck styles that remain compatible with the threaded plug. This wider range of container neck opening style also remain compatible with the tamper-evident overcap as disclosed herein.
A closure for a container opening according to one embodiment of the present invention comprises a plug including overcap-engaging forms and being constructed and arranged to be received within the container opening and an overcap including plug-engaging forms constructed and arranged for interfit with the overcap-engaging forms of the plug, the overcap being attached to the plug so as to create an integral assembly, wherein the overcap to plug interfit helps to prevent rotation of the overcap relative to the plug.
One object of the present disclosure is to provide an improved closure for a container including a plastic plug and overcap.
For the purposes of promoting an understanding of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated device and its use, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates.
Referring to
Referring to
Each cylindrical wall 27 and 47 includes a raised annular rib 27a and 47a, respectively, that is embedded into its corresponding gasket 22 and 42, respectively. Gaskets 22 and 42 are substantially identical to each other in form, fit and function. In this particular application as disclosed for the two prior art systems, gaskets 22 and 42 are square-cut gaskets that fit between the radial flange of the plastic plug and the upper surface of the wall that defines the container neck opening. With regard to the plastic plugs 23 and 43, these two components are substantially identical to each other in form, fit and function.
Referring now to
With continued reference to
In the exemplary embodiment there are a total of nineteen recesses 73 and thus a corresponding total of nineteen raised spline edges 75. The recesses 73 are arranged in an annular series. This number is believed to be the right balance between concave depth, circumferential width and the number of interfit locations with corresponding projections formed on the overcap 61. The plug 60 includes an interior shelf 80 and the open space 81 above shelf 80 includes radially inwardly-projecting forms 82 and alternating recesses 83. Each form 82 defines a central opening 82a. These interior shapes that are defined above shelf 80 are used for plug tightening and removal after initial opening. As will be described, the overcap 61 is securely attached to the plug 60 (see
Referring to
The annular wall 91 of overcap 61 is shaped or contoured with nineteen radially inwardly extending projections 96. Each projection 96 has a smoothly curved convex geometry and a spacing that closely matches the concave geometry of each recess 73 in plastic plug 60. The projections 96 are arranged in an annular series. These matching shapes on the overcap 61 and plug 60 permit a close line-to-line and precise interfit of overcap 61 onto the top flange portion of plug 60 so that each projection 96 is fitted closely and precisely into a corresponding recess 73.
Although the radial depth of each recess 73 is not particularly significant in terms of its actual dimension, it is significant in the manner that each projection 96 is received. Further, the close fit of the inside diameter of wall 91 relative to and with the outside diameter of surface 72 helps to insure that overcap 61 will not turn or slip around plug 60. While the interfit of projections 96 and recesses 73 is one way of securing the overcap 61 and plug 60 together as an integral unit, the overcap 61 is rigidly and securely connected to plug 60 by ultrasonically welding these two components together. The actual weld locations can be a spot weld location in terms of the ultrasonic welding and a plurality of spot weld locations 98 are preferred. However, only one ultrasonic weld location would be sufficient.
While recesses 73 and projections 96 have a specific curvature and geometry, what is illustrated and described is only one of several options. Functionally, the important characteristic is the interfit between the plug 60 and overcap 61 so as to help prevent relative turning or rotation between these two parts as the plug portion is being threaded into the container opening. The curved recesses 73 and corresponding and cooperating projections 96 can be changed to a different shape and can be annularly arranged in a different number. The male-female relationship can also be reversed.
With the overcap 61 securely fitted onto 60 (assembly 97) and ultrasonically welded into an integral combination, the
As illustrated in
Referring now to
Referring now to
In terms of the primary component parts of fixture 105, there is a control lever 109 for valve actuation, an automatic, reversible wench drive 111, a torque-limiting drive assembly 112, a counterbalance eyelet 113, a sliding detent ring 114, a movable piston 115, the six collets 110 and associated components and mounting hardware so as to assemble these primary component parts. Some of these associated components create an outer housing 117 that receives drive assembly 112, piston 115 and at least portions of the six collets 110. It is this outer housing 117 that helps to define the interior chamber 129. Also included as one of the primary component parts of tooling fixture 105 is a holder 116 that is also positioned within the outer housing 117 and cooperates with the six collets 110 so as to control their movement and positioning as will be described. Further, holder 116 is positioned relative to piston 115 such that the introduction of air pressure at their interface causes these two components to separate from one another by the introduction of this air pressure into the interior of the outer housing.
The method of operation and use of tooling fixture 105 begins with the collets 110 in an open or unclamped position as illustrated in
When a plug/overcap assembly 97 is to be installed into a container opening, the sliding detent ring 114 is lowered from the
Referring now to
The introduction of air pressure by way of inlet 127 pushes up on piston 115 and draws the ends of the collets 110 inwardly, thereby closing tightly on the assembly 97. The air pressure is set for the desired holding or gripping force based on relative sizes and dimensions and based on the amount of movement permitted with the piston and the angle of incline on each of the collets. The assembly 97 must be and is securely and tightly gripped by the collets 110 before there is any possibility of turning or rotating the assembly 97 for its threaded insertion into the internally-threaded opening 62 of the container. In order to insure that the collets have tightly grasped onto assembly 97 before air is delivered to the wrench drive, an air valve is triggered by the movement of the piston 115. Until the piston moves to the desired position, this valve is not opened so that air can be delivered to the wrench drive 111. However, the piston first moves to a location that causes the collets 110 to tightly grasp onto assembly 97. After the assembly 97 is tightly grasped by the six collets, and only after this occurs is air pressure delivered to wrench drive 111. Accordingly, there is no risk of trying to start rotating or turning assembly 97 for threaded insertion until assembly 97 is properly and securely gripped by the collets.
One possible design variation to this foregoing sequence is to arrange the air flow lines with a sensor that is constructed and arranged to sense a “no-flow” condition after air flow is initiated. The initiated air flow moves the piston 115, as has been described, and when the piston movement reaches its limit, the air flow into chamber 129 stops. The sensor mentioned above is constructed and arranged to recognize that the air flow into chamber 129 has stopped and, at that point, the sensor triggers an opening or open valve condition so that an air flow path is provided to the wrench drive 111. This construction sequences the air flows such that rotation of the collets 110 does not begin until the assembly 97 is firmly and securely grasped by those collets 110.
The drive head 135 has a ratchet design that is reversible and includes a driveshaft 136 that connects to drive assembly 112 and from there, through sleeve 130 and ultimately collets 110. As the plug 60 portion of assembly 97 becomes fully tightened into opening 62, a resistive force level is sensed by the torque-limiting drive assembly 112 (see
With continued reference to
A still further design variation for the illustrated tooling and for the method of use and the method of installing is to generate the air pressure for clamping the collets 110 and for rotation of the collets 110 concurrently, rather than sequentially. This approach avoids the need for any valving or sensing that would otherwise be required for the sequential operation of the air flows. What occurs with this alternate design is to slowly turn or rotate the group of six collets 110 as the piston 115 is lifting upwardly and pulling upwardly on the collets. This rotation of the group of collets continues as the individual collets 110 gradually close onto assembly 97. Once the assembly is grasped or gripped securely by the collets 110, the rotation causes the plug body to be threaded into the container opening 62.
If the plug and overcap assembly 97 is to be removed by the drum manufacturer or by a filler, the same tooling fixture 105 is used in reverse. The grasping procedure is the same using air pressure to clamp the collets 110 around the outside diameter of the assembly 97. Thereafter, the wrench drive 111 is used but now in a reversed direction so as to unthread the assembly 97 from within opening 62.
Referring now to
Overcap 142 is generally the same as overcap 60 in terms of form and function. The difference between overcap 142 and overcap 61 is the inside diameter size of outer wall 143 and similarly the outside diameter size of that wall. However, in terms of the present invention, the focus is on the size of the inside diameter of outer wall 143. This is the wall surface where the projections 144 are formed for interfit with recesses 141. The difference is that with a larger inside diameter, there is a slight clearance or separation between the projections 144 and the recesses 141 at the time of initial assembly of the overcap 142 onto and over the top of plug 140. This assembly 145 is illustrated in
Referring now to
Overcap 155 is a substantially flat, relatively thin disk and one species of overcap 155 is a unitary plastic member. In another species of overcap 155, it is a heat-weld foil disk. Overcap 155, regardless of the species style, is constructed and arranged to be securely attached to the top 156 of plug 150. For the plastic species, this attachment is accomplished by ultrasonic welding at one or more spots. For the foil species, this attachment is accomplished by heat welding, similar to typical foil liners.
The overcap 155 has an outside diameter size that generally corresponds to the outside diameter size of radial flange 152. As such, with the overcap 155 centered on the plug at the time of attachment, the outer circular edges of the plug 150 and overcap 155 are generally aligned with each other and are generally concentric. This assembly 156 is illustrated in
Overcap 155 is illustrated with the punch through center panel 93 and the annular ring portion 95 as previously illustrated with the earlier overcap embodiments. With the foil species, this opening structure can be removed and thus require the user to pierce the foil disk and either manually or with pliers tear the disk off, or at least tear an opening in the disk sufficient to reach the interior forms of the plug for purposes of removing the plug from the container at the time of initial use.
While the preferred embodiment of the invention has been illustrated and described in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.