CA1187664A - Mold for tamper proof closure - Google Patents
Mold for tamper proof closureInfo
- Publication number
- CA1187664A CA1187664A CA000417813A CA417813A CA1187664A CA 1187664 A CA1187664 A CA 1187664A CA 000417813 A CA000417813 A CA 000417813A CA 417813 A CA417813 A CA 417813A CA 1187664 A CA1187664 A CA 1187664A
- Authority
- CA
- Canada
- Prior art keywords
- closure
- forming
- sidewall
- core
- cavity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
ABSTRACT OF THE DISCLOSURE
A method and means for molding a tamper proof closure for threaded container having a retainer thereon wherein closure has a body with an internally threaded straight sidewall and a breakaway skirt having a wedge shaped internal ring located thereon which is adapted to slide over the retainer on the container, the breakaway skirt being separated from the remainder of the sidewall by a frangible portion disposed therebetween and formed from an undercut from the inside of the closure outward.
A method and means for molding a tamper proof closure for threaded container having a retainer thereon wherein closure has a body with an internally threaded straight sidewall and a breakaway skirt having a wedge shaped internal ring located thereon which is adapted to slide over the retainer on the container, the breakaway skirt being separated from the remainder of the sidewall by a frangible portion disposed therebetween and formed from an undercut from the inside of the closure outward.
Description
6~
The present invention relates to a mold and a method oF
molding an improved tamper indicating closure.
B~CKGROUND OF T~IE INVENTION
There presently exist numerous tamper indicating closures for containers, bottles, etc. These closures come in various materials for example, metals and plastics predominently~ Metal closures however have the disadvantage of being expensive, and prone to leaving sharp edges which can cut the user's fingers.
Some closures are adapted to allow for a portion thereof to be left on the container after opening as an indication of tampering.
This is often accomplished by requiring the user to pull or strip from the closure a band, typically situated between the threads of the closure and the portion remaining on the container to allow the unscrewing of the closure. Thusg two operations are required for removal of the closure in addition to the discarding of the band. In addition, experience has proven that the tamper proof evidence in these closures many times will not remain on the neck of the bottle.
Other types of closures provide for a breakaway portion which breaks from the closure during unscrewing thereby providing for a single operation. This type of closure may come in a single piece or a plurality of pieces~ Many of these closures are made of inappropriate material, involve complicated design of the closure and/or container cr involve complex molding techniques, limiting their application.
Thus, it would be advantageous to have a simple but .
effective tamper proof closure which would indicate tampering once opened, inhibit reuse of the container for bogus material, yet be asthestically pleasing with straight walls and effective in resealing d bottle. It would also be advantageous to have a closure which could be readily molded and used on a bottle with a relatively simple neck thus reducing the cost of the manufacturing of the bottle.
In this regardl typical molding techniques for closures usually require that the cores be skepped or offset to facilitate molding so as to get the closure off the core. Such molding does not lend itself to the production of straight molded closures and obviously requires involved complicated molding techniques.
In the molding of closures that do have straight sidewalls, the molds usually require a collapsible core or a cam action cavity to enable the removal of the closure therefrom, obviously complicated and expensive.
A further consideration in closure design is the material from which it is molded and the molding technique required. In many cases whether strip molding is used depends upon the type of material involved since it can result in excessive stretching of the closure.
Accordingly, there is a need for a means for molding a straight sided closure which is relatively simple yet effective.
_U~ AIIJ~
Accordingly, it is an object of the invention to provide for a means of molding a single piece tamper indicating closure suited for various types of containers which is relatively simple in ~8~64~i4 construction, operation and expense and which allows for the fabrication of a closure which is asthetic in appearance being straight walled with a breakaway skirt or portion thereon which will normally remain on the container when the closure is removed so as to indicate tampering.
A yet further object of the invention is to provide for a means of molding a tamper indicating closure which is readily removable from the core of the mold while allowing it to be made of a variety of resins, and does not require a core which is collapsible or a cam action cavity to remove the closureJ
The tamper indicating closure to be molded is formed in d single piece, with or without a liner, and is provided with a breakaway skirtO A flat crown or dome is provided and a sidewall downwardly extending therefrom. A breakaway skirt is coupled to the sidewall via a frangible connection comprising a serration or a plurality of straps formed out of the sidewall and positioned between the top of the breakaway skirt and the sidewall.
The inside wall of the breakaway skirt is molded so as to be provided with a continuous circumferentially extending wedge shaped ring. In one embodiment in this regard~ the wedge shaped ring includes a plurality of locking lugs which are formed in such a manner to assist in the screwing off of the closure from the core once the mold or cavity is removed. In another embodiment, the core of the mold is formed out of three parts to enable the stripping of closure therefrom. Once the cavity is removed, the first part of the core which forms the crown, sidewalls and threaded portion in cooperation with the cavity is axially displaced with respect to the ~87 Ei6~
second part of the core which also forms a portion of the sidewall in conjunction with the frangible portion and breakaway skirt.
Contemporaneously, a third part of the core, in the shape of a sleeve, serves to assist in pushing the closure, particularly the breakaway skirt thereof, off the second part of the core thereby advantageously preventing undue strain on the frangible portion so as to prevent its fracture.
Thereafter tlle closure is removed from the first part of the core by unthreading.
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The above mentioned as well as other objects and advantages of the present invention will become more apparent from the description thereof which is to be taken in conjunction with the accompanying drawings in which:
Figure l is a partially sectional view of the cavity and core for a tamper indicating closure, incorporating the teachings of the present invention;
Figure 2 is a substantially sectional view of the cavity and the core with a tamper indicating closure formed therebetween, Figure 3 is a partially sectional view of a second embodiment showing a cavity and three piece core for a tamper indicating closure, incorporating the teachings of the present invention;
Figure 4 is a partially sectional exploded view of the cavity and core shown in Figure 3;
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Figure 5 is a partially sectional view of the core with a tamper proof closure formed thereon and the cavity removed from the core;
Figure 6 is a partially sectional view of the parts of the core in phantom and advanced to enable the stripping of the closure thereFrom;
Figure 7 is a perspective view of another embodiment of the core having 1ug notches thereon to ~orm lugs on the closure allowing the screwing off of the closure in certain applications;
Figure 8 is a partial enlarged view of the notches on the core shown in Figure 7; and Figure 9 is an enlarged view of raised lugs on the core to form notches on the closure allowing the screwing off of the closure in certain applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to Figures 1 and 2, there is shown a means for readily molding a tamper indicating closure 10, as shown in Figure 2.
With refPrence to Figure 1~ there is shown a mold or cavity 12 having an openiny 74 to allow the material (i.e., polypropylene, polyethylene etc.) to be molded to enter the CdVity when it is placed over a core 76 so as to form the closure 10 as described in the immediately aforementioned application.
As shown in Figure 2, the outer surface of the core 76 compliments the internal surface of the closure, with the internal surface of the cavity complimenting the external surface of the ~1!376~
closureD Note that the point of widest diameter of ~he core at 78 forms an undercut Ineans and in conjunction with the cavity 72, a point of reduced area therebetween on the closure 10, allowing formation of the frangible portion between the breakaway portion 20 and sidewall 14. Variation of the width of this area allows for a variation of the thickness of the frangible portion to a point where the frangible portion would be formed just out of the vertical side ribs thereby providing a serrated appearance around the closure 10.
Once the closure is formed on the core 76, the cavity 72 is lifted off. The closure 10 is then merely turned off of the core.
As this occurs~ the angular upper surface of the wedge shaped internal riny assists in allowing this without causing undue stress on the frangible portion. Also the locking 1ugs 60 on the closure 10, at point 66 are practically flush with surface 5~ and ease the closure gradually off the core with the thickness of surface 64 increasing gradually expanding the breakaway portion 20 until the apex 58 of the ring and lugs 60 have passed the point of the widest diameter of the core at 78. The diameter of the apex 58 is sufficiently large so that it clears the threaded portion of the core, and continued turning causes the closure to turn completely off of the core. Accordingly, the closure 10 may be readily molded out of a variety of materials and removed from the core of the mold without the necessity of a complicated procedure or collapsible core, or cam action cavity.
Also, as aforenoted, at point 78 during molding, the sidewall 14 of the closure is the thinnest and by using the vertical ribs in conjunction with a thin wall, readily allows for the 7Çi ~
formation of the serrated line without any complicated procedure or molding.
Turning now to the embodiment shown in Figures 2-6, there is shown a molding apparatus for a tamper proof closure.
Briefly, as can be seen in Figures 3, 5 and 6, the closure 110 has a dome or crown 112 which is circular in form with a flat external surface. Extending downward from the crown is an annular sidewall 114 on which is located a plurality of outwardly tapered vertical ribs 116 which facilitate grasping the closure. Attached to the sidewall 114, via several longitudinal straps or connectors 118 making up the frangible portion, is a breakaway skirt 120.
The sidewall 114 has located on its internal surface a helical thread 122 which would correspond, in a mating like relation-ship, to the thread on a container to which it is placed so as to allow the closure to be screwed on and off. Below thread 122 is a straight cylindrical portion 124 which continues to the bottom rim 126 of the wall.
The breakaway skirt 120 has smooth outer surface 128 and two inner surfaces 130 and 132 forming a wedge shaped internal ring 134, The surface 130 as can be seen is formed of actually two angling surfaces. Inner surface 130 and outer surface 128 form the top 136 of the sklrt, while inner surface 132 and outer surfaçe 128 form the bottom 138 of the skirt.
Note that during the molding process the breakaway skirt 120 may have a circumference slightly larger than that of the sidewall 114. If this occurs, the closure will however straighten out when placed on the container.
The skirt 120 is connectecl at the lower end oF wall 114 by several horizontal straps or connectors 1189 with the straps being affixed to the breakaway skirt 1209 at 136. These straps are arranged around the bottom portion of wall 114 and may be at equal arc length to each other and seven or eight in number, although not limited thereby. Note that the straps 118 may be formed out of a select number of vertical ribs 116 if formed in an area where the ribs extend by undercutting outwardly through the sidewall 114 about its circumference as will be apparent. The straps are relatively short and the space between the sidewall 114 and the breakaway skirt 120 is slight (approximately .005") giving the closure a clean, elegant look.
As can be seen from Figures 3-6, there is shown a mold or cavity 142 having an opening 144 to allow the material (iDe., polypropylene, polyethylene etc.) to be molded to enter the cavity when it is placed on the core 146, so as to Form the closure 110.
Accordingly, the outer surface of the core compliments the internal surface of the closurP 1109 with the internal surface of the cavity 142 complimenting the external surFace of the closure, as shown in Figure 3. Note however that the inner surface 130 is Formed by a complimentary surface of an annular V-shaped groove 148 which similarly comprises two angular surFaces. The upper of these surfaces 148a includes an undercut means or upper edge 150 which is approximately of equal diameter as that oF the internal diameter of the cavity adjacent thereto so that in the molding of the closure a space is formed (approximately .005") between the sidewall 114 and the breakaway skirt 120. To provide a frangible portion, connections ~L871~
at this junction a plurality o-f notches 152 are provicled on the edge 150 ard serve to allow the forrnation of the straps or connectors 118 on the closure. If the vertical ribs 116 of the closure extend down to the notches 152, this allows for the straps 118 to be formed out of a select number of the ribs, depending upon the width of the notch. Otherwise the straps can be formed out of the sidewall 114.
Turning now to Figure 4, it shows an exploded view of the molding apparatus which comprises the cavity 142 as aforenoted and the core generally designated 146. The core 146 comprises three separate pieces axially displaceable with respect to each other.
The first piece or head section 153 includes a cylindrical head or stem portion 154 having a helical groove 156 thereon which serves to form the helical thread of the closure, The head 154 is attached to a cylindrical shaft 158 which is slidably maintained in a channel 160 formed in the second portion or cylindrical base 162 of the coreu The base 162 includes a flat annular surface 163 which serves to form a portion 124 of sidewall 114. Below surface 163 is an annular V-shaped groove 148 which serves to form the wedge shaped internal ring 134 of the breakaway skirt 120 as aforenoted. As part of this groove is surface 148 which terminates in edge 150 having notch 152 located thereon as herebefore described.
Below the groove 148 is an annular smooth surface 164 havins a diameter slightly smaller than the interior sur-face 166 of the third portion or sleeve 168 which is slidably disposed thereon~
This diameter is approximately equal to that of the edge 150 so as to allow the sleeve 168 to be axially displaced thereover for reasons that will be apparent.
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Once the formed closure 110 is formed as shown in Figure 4, to remove it from the molding apparatus the first step is to remove the cavity 142 from the core. As shown in Figure 5, the cavity 142 is readi1y axially displaced therefrom in the direction indicated by the arrows. Next the head portion 153 is axially displaced from the base 162 which pulls the breakaway skirt 120 from the groove 14~.
Due to the angle of surface 130, this allows for the easing off of the breakaway skirt 120 to a point beyond edge 150 without Fracturing the frangible portion 118. Beyond this point, the closure can be axially withdrawn further and then screwed off of the head section 153. Note that to assist in removal of the closure from the core, the sleeve 168 moves contemporaneously with the movement of the head portion 153 as shown in phantom in Figure 6 so as to engage the bottom 138 of the breakaway skirt 120 and push it or "strip" the lS closure off the base 162 thereby aiding in preventing a fracture of the straps 118. Note further that once the closure is off the base 162, it may be unthreaded therefrom by placing a rotational force on the sidewall 114 so as to unscrew the closure, as is standardly done, while maintaining the head section 153 fixed. When the closure has been removed from the core9 the pieces of the core return to their initial positions as shown in Figure 3 to prepare for the molding of another closure.
However in certain applications rather than applyiny a rotational external force on the sidewall 114 and maintaining the 2s head section 153 fixed, an alternate means of removing the closurefrom this section is to hold the closure while turning the head section. This typically requires vertical lugs or notches to be positioned on the closure's interior beneath the -threaded portion.
In this regard, reference is made -to Figures 7 and 8 and which show alternate embodiments of the core which is similar to that previously discussed except for providing the lugs or notches, so like parts to the immediately preceeding embodiment will be similarly numbered and designated with a prime. As can be seen in Figures 7 and 8, the core is provided with a plurality of vertical cutouts or notches 170 positioned on the flat annular surface 163 of the head section 153' and are positioned between the helical groove 154' and edge 150'.
Since these are cutouts9 during molding they will serve to provide vertical lugs on the interior surface of the closure which should not be to deep to otherwise interfere with the removal of the closure from the core, in which to secure the closure while the head section 153' is unthreaded therefrom.
Similarly in Figure 9 rather than forming lugs on the interior surface of the closure, raised notches are formed thereon by way of raised lug portions 172 provided on surface 163' and operate to provide a means of rota-tionally fixing the closure as the head section is unthreaded therefrom.
Clearly then from the aforenoted invention, the object and advantages are readily realized and although preferred embodiments have been disclosed and described in detail herein, its scope should not be limited thereby rather its scope should be determined by that of the appended claims.
,
The present invention relates to a mold and a method oF
molding an improved tamper indicating closure.
B~CKGROUND OF T~IE INVENTION
There presently exist numerous tamper indicating closures for containers, bottles, etc. These closures come in various materials for example, metals and plastics predominently~ Metal closures however have the disadvantage of being expensive, and prone to leaving sharp edges which can cut the user's fingers.
Some closures are adapted to allow for a portion thereof to be left on the container after opening as an indication of tampering.
This is often accomplished by requiring the user to pull or strip from the closure a band, typically situated between the threads of the closure and the portion remaining on the container to allow the unscrewing of the closure. Thusg two operations are required for removal of the closure in addition to the discarding of the band. In addition, experience has proven that the tamper proof evidence in these closures many times will not remain on the neck of the bottle.
Other types of closures provide for a breakaway portion which breaks from the closure during unscrewing thereby providing for a single operation. This type of closure may come in a single piece or a plurality of pieces~ Many of these closures are made of inappropriate material, involve complicated design of the closure and/or container cr involve complex molding techniques, limiting their application.
Thus, it would be advantageous to have a simple but .
effective tamper proof closure which would indicate tampering once opened, inhibit reuse of the container for bogus material, yet be asthestically pleasing with straight walls and effective in resealing d bottle. It would also be advantageous to have a closure which could be readily molded and used on a bottle with a relatively simple neck thus reducing the cost of the manufacturing of the bottle.
In this regardl typical molding techniques for closures usually require that the cores be skepped or offset to facilitate molding so as to get the closure off the core. Such molding does not lend itself to the production of straight molded closures and obviously requires involved complicated molding techniques.
In the molding of closures that do have straight sidewalls, the molds usually require a collapsible core or a cam action cavity to enable the removal of the closure therefrom, obviously complicated and expensive.
A further consideration in closure design is the material from which it is molded and the molding technique required. In many cases whether strip molding is used depends upon the type of material involved since it can result in excessive stretching of the closure.
Accordingly, there is a need for a means for molding a straight sided closure which is relatively simple yet effective.
_U~ AIIJ~
Accordingly, it is an object of the invention to provide for a means of molding a single piece tamper indicating closure suited for various types of containers which is relatively simple in ~8~64~i4 construction, operation and expense and which allows for the fabrication of a closure which is asthetic in appearance being straight walled with a breakaway skirt or portion thereon which will normally remain on the container when the closure is removed so as to indicate tampering.
A yet further object of the invention is to provide for a means of molding a tamper indicating closure which is readily removable from the core of the mold while allowing it to be made of a variety of resins, and does not require a core which is collapsible or a cam action cavity to remove the closureJ
The tamper indicating closure to be molded is formed in d single piece, with or without a liner, and is provided with a breakaway skirtO A flat crown or dome is provided and a sidewall downwardly extending therefrom. A breakaway skirt is coupled to the sidewall via a frangible connection comprising a serration or a plurality of straps formed out of the sidewall and positioned between the top of the breakaway skirt and the sidewall.
The inside wall of the breakaway skirt is molded so as to be provided with a continuous circumferentially extending wedge shaped ring. In one embodiment in this regard~ the wedge shaped ring includes a plurality of locking lugs which are formed in such a manner to assist in the screwing off of the closure from the core once the mold or cavity is removed. In another embodiment, the core of the mold is formed out of three parts to enable the stripping of closure therefrom. Once the cavity is removed, the first part of the core which forms the crown, sidewalls and threaded portion in cooperation with the cavity is axially displaced with respect to the ~87 Ei6~
second part of the core which also forms a portion of the sidewall in conjunction with the frangible portion and breakaway skirt.
Contemporaneously, a third part of the core, in the shape of a sleeve, serves to assist in pushing the closure, particularly the breakaway skirt thereof, off the second part of the core thereby advantageously preventing undue strain on the frangible portion so as to prevent its fracture.
Thereafter tlle closure is removed from the first part of the core by unthreading.
~
The above mentioned as well as other objects and advantages of the present invention will become more apparent from the description thereof which is to be taken in conjunction with the accompanying drawings in which:
Figure l is a partially sectional view of the cavity and core for a tamper indicating closure, incorporating the teachings of the present invention;
Figure 2 is a substantially sectional view of the cavity and the core with a tamper indicating closure formed therebetween, Figure 3 is a partially sectional view of a second embodiment showing a cavity and three piece core for a tamper indicating closure, incorporating the teachings of the present invention;
Figure 4 is a partially sectional exploded view of the cavity and core shown in Figure 3;
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Figure 5 is a partially sectional view of the core with a tamper proof closure formed thereon and the cavity removed from the core;
Figure 6 is a partially sectional view of the parts of the core in phantom and advanced to enable the stripping of the closure thereFrom;
Figure 7 is a perspective view of another embodiment of the core having 1ug notches thereon to ~orm lugs on the closure allowing the screwing off of the closure in certain applications;
Figure 8 is a partial enlarged view of the notches on the core shown in Figure 7; and Figure 9 is an enlarged view of raised lugs on the core to form notches on the closure allowing the screwing off of the closure in certain applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to Figures 1 and 2, there is shown a means for readily molding a tamper indicating closure 10, as shown in Figure 2.
With refPrence to Figure 1~ there is shown a mold or cavity 12 having an openiny 74 to allow the material (i.e., polypropylene, polyethylene etc.) to be molded to enter the CdVity when it is placed over a core 76 so as to form the closure 10 as described in the immediately aforementioned application.
As shown in Figure 2, the outer surface of the core 76 compliments the internal surface of the closure, with the internal surface of the cavity complimenting the external surface of the ~1!376~
closureD Note that the point of widest diameter of ~he core at 78 forms an undercut Ineans and in conjunction with the cavity 72, a point of reduced area therebetween on the closure 10, allowing formation of the frangible portion between the breakaway portion 20 and sidewall 14. Variation of the width of this area allows for a variation of the thickness of the frangible portion to a point where the frangible portion would be formed just out of the vertical side ribs thereby providing a serrated appearance around the closure 10.
Once the closure is formed on the core 76, the cavity 72 is lifted off. The closure 10 is then merely turned off of the core.
As this occurs~ the angular upper surface of the wedge shaped internal riny assists in allowing this without causing undue stress on the frangible portion. Also the locking 1ugs 60 on the closure 10, at point 66 are practically flush with surface 5~ and ease the closure gradually off the core with the thickness of surface 64 increasing gradually expanding the breakaway portion 20 until the apex 58 of the ring and lugs 60 have passed the point of the widest diameter of the core at 78. The diameter of the apex 58 is sufficiently large so that it clears the threaded portion of the core, and continued turning causes the closure to turn completely off of the core. Accordingly, the closure 10 may be readily molded out of a variety of materials and removed from the core of the mold without the necessity of a complicated procedure or collapsible core, or cam action cavity.
Also, as aforenoted, at point 78 during molding, the sidewall 14 of the closure is the thinnest and by using the vertical ribs in conjunction with a thin wall, readily allows for the 7Çi ~
formation of the serrated line without any complicated procedure or molding.
Turning now to the embodiment shown in Figures 2-6, there is shown a molding apparatus for a tamper proof closure.
Briefly, as can be seen in Figures 3, 5 and 6, the closure 110 has a dome or crown 112 which is circular in form with a flat external surface. Extending downward from the crown is an annular sidewall 114 on which is located a plurality of outwardly tapered vertical ribs 116 which facilitate grasping the closure. Attached to the sidewall 114, via several longitudinal straps or connectors 118 making up the frangible portion, is a breakaway skirt 120.
The sidewall 114 has located on its internal surface a helical thread 122 which would correspond, in a mating like relation-ship, to the thread on a container to which it is placed so as to allow the closure to be screwed on and off. Below thread 122 is a straight cylindrical portion 124 which continues to the bottom rim 126 of the wall.
The breakaway skirt 120 has smooth outer surface 128 and two inner surfaces 130 and 132 forming a wedge shaped internal ring 134, The surface 130 as can be seen is formed of actually two angling surfaces. Inner surface 130 and outer surface 128 form the top 136 of the sklrt, while inner surface 132 and outer surfaçe 128 form the bottom 138 of the skirt.
Note that during the molding process the breakaway skirt 120 may have a circumference slightly larger than that of the sidewall 114. If this occurs, the closure will however straighten out when placed on the container.
The skirt 120 is connectecl at the lower end oF wall 114 by several horizontal straps or connectors 1189 with the straps being affixed to the breakaway skirt 1209 at 136. These straps are arranged around the bottom portion of wall 114 and may be at equal arc length to each other and seven or eight in number, although not limited thereby. Note that the straps 118 may be formed out of a select number of vertical ribs 116 if formed in an area where the ribs extend by undercutting outwardly through the sidewall 114 about its circumference as will be apparent. The straps are relatively short and the space between the sidewall 114 and the breakaway skirt 120 is slight (approximately .005") giving the closure a clean, elegant look.
As can be seen from Figures 3-6, there is shown a mold or cavity 142 having an opening 144 to allow the material (iDe., polypropylene, polyethylene etc.) to be molded to enter the cavity when it is placed on the core 146, so as to Form the closure 110.
Accordingly, the outer surface of the core compliments the internal surface of the closurP 1109 with the internal surface of the cavity 142 complimenting the external surFace of the closure, as shown in Figure 3. Note however that the inner surface 130 is Formed by a complimentary surface of an annular V-shaped groove 148 which similarly comprises two angular surFaces. The upper of these surfaces 148a includes an undercut means or upper edge 150 which is approximately of equal diameter as that oF the internal diameter of the cavity adjacent thereto so that in the molding of the closure a space is formed (approximately .005") between the sidewall 114 and the breakaway skirt 120. To provide a frangible portion, connections ~L871~
at this junction a plurality o-f notches 152 are provicled on the edge 150 ard serve to allow the forrnation of the straps or connectors 118 on the closure. If the vertical ribs 116 of the closure extend down to the notches 152, this allows for the straps 118 to be formed out of a select number of the ribs, depending upon the width of the notch. Otherwise the straps can be formed out of the sidewall 114.
Turning now to Figure 4, it shows an exploded view of the molding apparatus which comprises the cavity 142 as aforenoted and the core generally designated 146. The core 146 comprises three separate pieces axially displaceable with respect to each other.
The first piece or head section 153 includes a cylindrical head or stem portion 154 having a helical groove 156 thereon which serves to form the helical thread of the closure, The head 154 is attached to a cylindrical shaft 158 which is slidably maintained in a channel 160 formed in the second portion or cylindrical base 162 of the coreu The base 162 includes a flat annular surface 163 which serves to form a portion 124 of sidewall 114. Below surface 163 is an annular V-shaped groove 148 which serves to form the wedge shaped internal ring 134 of the breakaway skirt 120 as aforenoted. As part of this groove is surface 148 which terminates in edge 150 having notch 152 located thereon as herebefore described.
Below the groove 148 is an annular smooth surface 164 havins a diameter slightly smaller than the interior sur-face 166 of the third portion or sleeve 168 which is slidably disposed thereon~
This diameter is approximately equal to that of the edge 150 so as to allow the sleeve 168 to be axially displaced thereover for reasons that will be apparent.
69~
Once the formed closure 110 is formed as shown in Figure 4, to remove it from the molding apparatus the first step is to remove the cavity 142 from the core. As shown in Figure 5, the cavity 142 is readi1y axially displaced therefrom in the direction indicated by the arrows. Next the head portion 153 is axially displaced from the base 162 which pulls the breakaway skirt 120 from the groove 14~.
Due to the angle of surface 130, this allows for the easing off of the breakaway skirt 120 to a point beyond edge 150 without Fracturing the frangible portion 118. Beyond this point, the closure can be axially withdrawn further and then screwed off of the head section 153. Note that to assist in removal of the closure from the core, the sleeve 168 moves contemporaneously with the movement of the head portion 153 as shown in phantom in Figure 6 so as to engage the bottom 138 of the breakaway skirt 120 and push it or "strip" the lS closure off the base 162 thereby aiding in preventing a fracture of the straps 118. Note further that once the closure is off the base 162, it may be unthreaded therefrom by placing a rotational force on the sidewall 114 so as to unscrew the closure, as is standardly done, while maintaining the head section 153 fixed. When the closure has been removed from the core9 the pieces of the core return to their initial positions as shown in Figure 3 to prepare for the molding of another closure.
However in certain applications rather than applyiny a rotational external force on the sidewall 114 and maintaining the 2s head section 153 fixed, an alternate means of removing the closurefrom this section is to hold the closure while turning the head section. This typically requires vertical lugs or notches to be positioned on the closure's interior beneath the -threaded portion.
In this regard, reference is made -to Figures 7 and 8 and which show alternate embodiments of the core which is similar to that previously discussed except for providing the lugs or notches, so like parts to the immediately preceeding embodiment will be similarly numbered and designated with a prime. As can be seen in Figures 7 and 8, the core is provided with a plurality of vertical cutouts or notches 170 positioned on the flat annular surface 163 of the head section 153' and are positioned between the helical groove 154' and edge 150'.
Since these are cutouts9 during molding they will serve to provide vertical lugs on the interior surface of the closure which should not be to deep to otherwise interfere with the removal of the closure from the core, in which to secure the closure while the head section 153' is unthreaded therefrom.
Similarly in Figure 9 rather than forming lugs on the interior surface of the closure, raised notches are formed thereon by way of raised lug portions 172 provided on surface 163' and operate to provide a means of rota-tionally fixing the closure as the head section is unthreaded therefrom.
Clearly then from the aforenoted invention, the object and advantages are readily realized and although preferred embodiments have been disclosed and described in detail herein, its scope should not be limited thereby rather its scope should be determined by that of the appended claims.
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Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A molding device for use in forming an internally threaded tamper proof closure having a breakaway skirt connected to the sidewall by a frangible portion, with said device comprising:
cavity having a substantially stepless straight internal surface capable of forming the closure's exterior surface;
core adapted to be used in conjunction with the cavity so as to form a space therebetween when disposed in the cavity;
said core including an exterior surface on which is located a groove capable of forming a helical thread on the closure, an annular notch below said groove, having an upper and lower surface capable of forming an internal ring on the breakaway skirt conforming to said notch, and said core having disposed between said groove and said notch an undercut means at a predetermined diameter, the size of which determines the thickness of the frangible portion; and whereby a closure is formed in the space between said mold and core with the frangib1e portion formed at the space between the cavity and the undercut means.
cavity having a substantially stepless straight internal surface capable of forming the closure's exterior surface;
core adapted to be used in conjunction with the cavity so as to form a space therebetween when disposed in the cavity;
said core including an exterior surface on which is located a groove capable of forming a helical thread on the closure, an annular notch below said groove, having an upper and lower surface capable of forming an internal ring on the breakaway skirt conforming to said notch, and said core having disposed between said groove and said notch an undercut means at a predetermined diameter, the size of which determines the thickness of the frangible portion; and whereby a closure is formed in the space between said mold and core with the frangib1e portion formed at the space between the cavity and the undercut means.
2. The molding device in accordance with claim 1 wherein said annular notch is V-shaped to form a wedge shaped ring and further including: means located on the upper surface and capable of forming a locking lug on the breakaway skirt of a closure; said means includes a first portion substantially normal to the undercut means which gradually protrudes inward to a second point of maximum inward protrusion which is substantially flush with the upper surface with said means formed so as to permit the closure to be unscrewed from the core without severing the frangible portion.
3. The molding device in accordance with claim 2 wherein the internal surface of the cavity being notched so as to form vertical ribs on the sidewalls of the closure and the predetermined diameter of the undercut means being such so as to form the frangible portion out of vertical ribs on the closure.
4. A method of molding a straight sidewall tamper proof closure having a breakaway skirt connected to the sidewall by a frangible portion and adapted to engage a retaining means on a container, which includes the steps of:
providing a cavity having an interior surface substantially without steps and a core having exterior surface on which is located a groove capable of forming a helical thread on the sidewall of the closure;
forming said helical threads on the sidewall and forming a frangible portion between said sidewall and said breakaway skirt by an undercut on the inside of the sidewall; and forming the breakaway skirt having an internal ring by an annular notch in the core.
providing a cavity having an interior surface substantially without steps and a core having exterior surface on which is located a groove capable of forming a helical thread on the sidewall of the closure;
forming said helical threads on the sidewall and forming a frangible portion between said sidewall and said breakaway skirt by an undercut on the inside of the sidewall; and forming the breakaway skirt having an internal ring by an annular notch in the core.
5. The method in accordance with claim 4 which further includes the steps of:
providing vertical ribs on the closure's exterior; and forming the frangible portion in a serrated manner by reducing the sidewall thickness at the undercut so that the ribs essentially form the teeth of the serration.
providing vertical ribs on the closure's exterior; and forming the frangible portion in a serrated manner by reducing the sidewall thickness at the undercut so that the ribs essentially form the teeth of the serration.
6. The method in accordance with claims 4 or 5 which includes the steps of:
forming the internal ring in a wedge shape and forming a locking means on the ring with a portion of the locking means essentially smooth with a raised surface normal to the internal diameter of the ring which surface gradually recedes therefrom to allow the closure to be screwed off of the core.
forming the internal ring in a wedge shape and forming a locking means on the ring with a portion of the locking means essentially smooth with a raised surface normal to the internal diameter of the ring which surface gradually recedes therefrom to allow the closure to be screwed off of the core.
7. A molding device for use in forming an internally threaded tamper proof closure having a breakaway skirt connected to the sidewall by a frangible portion, with said device comprising:
cavity having a substantially stepless straight internal surface capable of forming the external surface of the closure's exterior surface;
core having a first and second portion adapted to be used in conjunction with the cavity so as to form a space therebetween when disposed in the cavity;
said cores first portion including an exterior surface on which is located a groove capable of forming a helical thread on the closure;
said cores second portion positioned below said first portion and includes on its exterior surface an annular notch capable of forming an internal ring on the breakaway skirt conforming to said notch;
undercut means on said core positioned between said groove and said notch having an outer diameter substantially equal to the internal diameter of the cavity adjacent said means when the core is positioned in the cavity;
a plurality of notches in said undercut means outer diameter adapted to form straps between the breakaway skirt and the sidewall of closure to create a frangible portion therebetween; and whereby a closure is formed in the space between said cavity and core and the frangible portion is formed at the space between the cavity and notches in the outer diameter of undercut means.
cavity having a substantially stepless straight internal surface capable of forming the external surface of the closure's exterior surface;
core having a first and second portion adapted to be used in conjunction with the cavity so as to form a space therebetween when disposed in the cavity;
said cores first portion including an exterior surface on which is located a groove capable of forming a helical thread on the closure;
said cores second portion positioned below said first portion and includes on its exterior surface an annular notch capable of forming an internal ring on the breakaway skirt conforming to said notch;
undercut means on said core positioned between said groove and said notch having an outer diameter substantially equal to the internal diameter of the cavity adjacent said means when the core is positioned in the cavity;
a plurality of notches in said undercut means outer diameter adapted to form straps between the breakaway skirt and the sidewall of closure to create a frangible portion therebetween; and whereby a closure is formed in the space between said cavity and core and the frangible portion is formed at the space between the cavity and notches in the outer diameter of undercut means.
8. The molding device in accordance with claim 7 wherein said annular notch is V-shaped to form a wedge shaped internal ring and said device further includes a third portion comprising a hollow sleeve positioned below the annular notch, said third portion axially displaceable from said second portion, and of a sufficient diameter that when axially displaced being engageable with the breakaway skirt to apply a force thereon to assist in the axial removal of the breakaway skirt from the core.
9. The molding device in accordance with claim 8 wherein said first portion is axially displaceable with respect to said second portion and adapted to be displaced contemporaneously with said third portion from the second portion to cause the removal of the breakaway skirt therefrom.
10. The molding device in accordance with claims 7, 8 or 9 wherein the internal surface of the cavity including vertically spaced grooves so as to form vertical ribs on the sidewall of the closure; and said undercut means and notches thereon serve to form straps out of said vertical ribs on the closure.
11. The molding device in accordance with claim 7 which includes lug forming means capable of forming a plurality of vertical raised lugs on the interior of the sidewall of the closure below the groove.
12. The molding device in accordance with claim 7 which includes notch forming means capable of forming a plurality of vertical notches on the interior of the sidewall of the closure below the groove.
13. A method of molding a straight sidewall tamper proof closure having a breakaway skirt connected to the sidewall by a frangible portion and adapted to engage a retaining means on a container, which includes the steps of:
providing a cavity having an interior surface substantially without steps;
providing a core having a first and second portion, the first portion including an exterior surface on which is located a groove capable of forming a helical thread on the closure; the second portion positioned below said first portion and includes on its exterior surface an annular notch capable of forming an internal ring on the breakaway skirt conforming to said notch;
forming said helical thread on the sidewall and forming a frangible portion between the sidewall and the breakaway skirt by an undercut on the inside of the sidewall;
forming the breakaway skirt having an internal ring by the annular notch; and axially displacing the first portion from the second portion to remove the breakaway skirt therefrom without fracturing the frangible portion.
providing a cavity having an interior surface substantially without steps;
providing a core having a first and second portion, the first portion including an exterior surface on which is located a groove capable of forming a helical thread on the closure; the second portion positioned below said first portion and includes on its exterior surface an annular notch capable of forming an internal ring on the breakaway skirt conforming to said notch;
forming said helical thread on the sidewall and forming a frangible portion between the sidewall and the breakaway skirt by an undercut on the inside of the sidewall;
forming the breakaway skirt having an internal ring by the annular notch; and axially displacing the first portion from the second portion to remove the breakaway skirt therefrom without fracturing the frangible portion.
14. The method in accordance with claim 13 which includes forming the internal ring by a V-shaped notch on the second portion and providing a third portion comprising a hollow sleeve positioned below the V-shaped notch and having a sufficient diameter to be engageable with the breakaway skirt when formed by said V-shaped notch; axially displacing said third portion from said second portion contemporaneously with the displacement of the first portion so as to remove the breakaway skirt from the second portion.
15. The method in accordance with claims 13 or 14 which include:
providing vertically spaced grooves on the interior of the cavity so as to form vertical ribs on the sidewall of the closure;
forming said ribs and forming said frangible portion as straps out of said vertical ribs on the closure.
providing vertically spaced grooves on the interior of the cavity so as to form vertical ribs on the sidewall of the closure;
forming said ribs and forming said frangible portion as straps out of said vertical ribs on the closure.
16. The method in accordance with claim 13 which includes providing lug forming means on said core capable of forming vertical lugs on the interior of the sidewall of the closure below the groove, and forming said lugs.
17. The method in accordance with claim 13 which includes providing notch forming means capable of forming a plurality of vertical notches on the interior sidewall of the closure below the groove, and forming said notches.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US41057482A | 1982-08-23 | 1982-08-23 | |
| US410,574 | 1989-09-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1187664A true CA1187664A (en) | 1985-05-28 |
Family
ID=23625324
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000417813A Expired CA1187664A (en) | 1982-08-23 | 1982-12-15 | Mold for tamper proof closure |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1187664A (en) |
-
1982
- 1982-12-15 CA CA000417813A patent/CA1187664A/en not_active Expired
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| MKEC | Expiry (correction) | ||
| MKEX | Expiry |