US2942747A

US2942747A - Container caps and methods for making them

Info

Publication number: US2942747A
Application number: US698082A
Authority: US
Inventors: Edward J Towns
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1957-11-22
Filing date: 1957-11-22
Publication date: 1960-06-28
Anticipated expiration: 1977-06-28

Description

June 28, 1960 E. J. TOWNS 2,942,747

CONTAINER CAPS AND METHODS FOR MAKING THEM Filed Nov. 22, 1957 2 Sheets-Sheet 1 I N VEN TOR. EDI 164 ED 77 Tan/A45 E. J. TOWNS June 28, 1960 CONTAINER CAPS AND METHODS FOR MAKING THEM Filed NOV. 22, 1957 2 Sheets-Sheet 2 V r 11: i s g 5 7 W 6 5 Z 1 Z 2 Ma 9 0% Z 1 United States Patent CONTAINER-CAPS AND METHODS FOR MAKING THEM Edward J. Towns, Livingston, NJ., assignor' to Minne= sota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware Filed Nov. 22, 1957, Ser. No. 698,082

7 Claims. (Cl. 215-46) This invention relates generally to a cap for sealing a container, such as a bottle, and in one of its more specific aspects to a cap which is adapted to provide an elTective original seal for a bottle and which is adapted to be readily reused, subsequent to initial use, to adequately reseal the bottle. This invention also pertains to an improved method for manufacturing resilient and reusable bottle caps.

A primary object of the invention is to provide a reusable bottle cap having improved features of construction and design.

Another object of the invention is to provide a bottle cap which is adapted (ti) to be readily applied to a bottle or the like and serve as an effective original seal therefor, (b) to be easily removed from .the bottle, as required, and (c) to be readily and quickly reapplied to the bottle to thereby adequately reseal the same.

The invention has for another object the provision of a reusable bottle cap which indicates visually, whenin active use, whether it is being used to effect original sealing or resealing of the bottle.

A further object of the invention is to provide a bottle cap of the character indicated that is'simple and attractive in design, that is durable in construction, that is reasonable in manufacturing cost and that is capable of performing its intended functions in a satisfactory and trouble-free manner.

To the end that the foregoing objectives may be attained, a bottle cap according to this invention is unitary in construction and is made of a suitable resinous composition which may be thermoplastic and/or thermosetting material which is readily moldable and which has the properties of being flexible, resilient, tearable, and inert and impervious to moisture and common gases. While polyethylene is preferred, it is to be understood that other thermoplastic or thermosetting materials having similar properties and characteristics may be used in place thereof.

The cap comprises a top wall and outer and inner tubular walls depending from the top wall and open at their lower ends. The inner wall is spaced from and substantially coaxial with the outer wall. An annular bead is provided atthe lower end of the outer wall and projects inwardly thereof. This bead has a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface. The recesses extend into the outer wall but terminate inwardly of both the inner and outer surfaces of the outer wall. The recesses may be of any desired form and, the parts of the cap defining the recesses constitute weakened areas that are tearable in the course of removing the cap from a bottle by means of a bottle opener or similar device.

The cap is adapted to be readily placed on a bottle and form an effective seal therewith as will be explained further along herein. When the cap is used to provide an original seal for the bottle, the parts areso arranged that the recesses are not visible and the outer wall is continuous and uninterrupted by slits, tears, or the like.

Patented June 28, 1961) At the time the cap is removed from the bottle the outer wall is partially torn in the region of one or two of the recesses. The cap may-be reused to reseal the bottle by repositioning it thereon. When the cap is used as a resealer, the tears appearing in the outer wall serve as visible indications that the cap is not an original sealer, but is being used for resealing purposes.

I find that for best results the inner tubular wall of the cap should be preferably somewhat softer and more pliable than the outer tubular wall. Accordingly, it is recommended that different thermoplastic and/ or thermoset compositions be used for the outer and inner walls. If desired, the cap may be made of two polyethylene compositions having requisite characteristics, which are molded to obtain a unitary or one-piece cap construction as will be described further along in this description.

The enumerated objects and other objects, together with the advantages of this invention, will be readily understood by persons skilled in the art from the following detailed description taken in conjunction with the accompanying drawings.

In the drawings:

Fig. 1 is a perspective 'view of a cap con'structed'in accordance with this invention operatively mounted-ona bottle;

Fig. 2 is a central vertical cross-sectional view through the cap and bottle assembly shown in Fig. l;

Fig. 3 is a bottom plan view of the cap showniri a Fig. 4 is an enlarged fragmentary view of a portion of Fig. 3; i

Fig. 5 is an enlarged view of the left hand portion of only the cap of Fig. 2;

Fig. 6 corresponds to Fig. 1 and illustrates the cap in the course of its being removed from the bottle with the aid of a bottle opener;

Fig. 7 also correspondsto Fig. land depicts the appearance of the cap when it is being reused for the purpose of resealing the bottle; 7

Fig. 8 is an enlarged central vertical cross sectional view through the cap shown in other views and illustrates the parts thereof that are molded from one composition and the parts that are molded from a second composition in accordance with this invention;

Fig. 9 is a view in vertical cross section of an arrangement of molding apparatus for forming certain parts of the cap of this invention;

Fig. 10 is similar to Fig. 9 and illustrates molding apparatus for forming the remaining parts of the cap; and

Fig. 11 is a perspective view of a separating plate.

Reference is now had to the drawings wherein like reference characters denote corresponding parts throughout the several views. There is illustrated in Figs. 1 and 2 the upper portion of a bottle B and a cap C of this invention positioned on and forming a seal with the bottle.

Bottle B is preferably made of glass and may be of any conventional construction and .design that is com monly used to store gas-containing liquids, such as ginger ale, carbonated water and the like. The bottle, to the extent that it is illustrated, includes a tubular neck 10 having an inner surface 11 and terminating in a pair of outer annular beads, namely an upper bead 12 and a lower bead 13. These beads merge and define an annular groove 14, as best shown in Fig. 2.

Cap C comprises a circular top wall 15, a depending outer tubular wall or skirt 16 and a depending inner tubular wall or sealing ring 17 that is spaced from and coaxial with the outer wall.

Walls

15, 16, and 17 are imperforate. Top wall 15 carries a plurality of radial stifiening ribs 18 that are positioned wholly within inner wall 17. The lower end of wall 16 includes an inwardly ethylene composition.

projecting annular head 19. plurality of circumferentially spaced blind recesses 20 extend into wall 16 as shown in Figs. 4 and 5, but terminate inwardly of the upper inner surface of bead 19. The .parts which define 7 individual -20 constitute weakened ae ions of the 61gb. -I-f desired, there an pdsitfoned'on the ribs 18 a fttle'c'ap linerltnot shown) of'aiiy'of the types known 'tbthe'a'r't. I

en g 'a C is ori inally a plied to bottle B, it is Hela ed sufii'iently to "soften lits p'arts and .pern1it. pos ition- -n the bottle as shown in Fig. 2, with inner wall 17 disposedin the bottle and forming intimate contact with J t tle surface 11 and bead 1 9 engaging outer bead 13 o f the-bottle as :shown. 7 {Eris-is -accomplished without tearing or otherwise breaking through outer wall 16 or bead 19. j V M p I 1 Assuming that the bottle contains a carbonated liquid, the fluid pressure within the bottle acts 'on top wall 15 and inner wall 17 a "manner to obtain an effective seal betweeirthe bottle andthe cap. The bottle and its contents may now be transported, stored or displayed under normally encountered temperature and pressure conditions without 'distupbing the seal. The fact that top wall 15 and outer wall 16 arej 'continuous and-uninter rupted by tears or other disfigura'tions serves as a visible indication to a purchaser that the bottle is under its original seat. In other words, the customer is assured "that the original "seal has not been broken and that the I.

. original contents a-re'intact.

The cap may be readily removed frprn -t hc bottle by includes a handle 21, an upper jaw 22 and a lower jaw The opener isadapted to engage the. cap withits upper jaw bearing on top wall 15 and its lower jaw hooked ainder outerl-wall m and engaging bead --1-9. The opener is tilted upwardly in the usual mahner to .prythe cap from the bottle. in the course of suchfprying, the

. ni'eans of'a conventional bottle=opener 0 (Fig. 6)f which 7 4 shown in Fig. 9, the ends of the slot 3:5 communicate with narrow cylindrical openings 9 which in turn communicate with annular groove 8 in'registry with groove 23. A polyethylene or other resinous composition of predetermined desirable properties is injected by the use of pressure and heat through 'the central opening in the tube 3%), into and through the confined slot 35, into and thrbu-gh the pair of narrowe ilindfical openings 9 and into the mold space *d'e'fined by

tlie grooves

8 and 28 to thereby form the annular inner wall 17 together with an annular 1 1112 7 1-7 a integral themwi-th and -have a pair of space annular beads 475-011the-llppelfifafie therwf Block 31 is adapted to be replaced by a similar block 37 for the purpose "offforining "top wail pants, ribs 18, outer wall16 and bead d9. As shownin Fig. 10, block 37 and mold 27 define a space 33 corresponding in size and configuration to outer wall 16. Block' 32 is likewise replaced by a similar block 32a and spaced above the earlier formed portions of the cap, as indicated at 39. This construction permits ready injection ofa second polyethylene or other resinous composition 4%) (Fig. 8) of the desired characteristics into the 'mold spaces to form top wall part'1 5,-ribs 18, outer wall 16 together with its bead 1 9. The composition is in "a molten or semi-molten state during molding, whereby fusion occurs between composition 40 and ring 17a so that wa1l-17 and top wall 1 5 are bonded together to obtain a unitary cap. 7 I 'Recess es 20 aretpreferably formedrinthe lower end 'of outer wall :16 "after molding is completediand the "cap is removed from the molding apparatus. It willbe-apa preciated that the reces'ses may be formed during the moldingprocedurqif desired.

opener" causes partial {tearing of -outer 'wall 16"and bead 19 in the regions of recesses 20 that -are-adjacent jaw 23,

j as shown in Fig. 6. Typical tear lines resulting from use of the-opener areindicated-by-numeral 24 in Figs. 6 and 7.-

Despite the tears resulting from breaking the original seal, the eap may -be repeatedly reused to :f'reseal-th'e contents of the bottle or other bottles. Tearlines 24cm:-

' stitute an indication to a user that the cap is being-used for rescaling purposes as distinguished from original sealing. t

{As was "mentioned earlier in this description, inner tubular wall'17 is preferably made ofia thermoplastic t composition that 'is somewhat softer, mor'e lpliable and thereforenflore flexible -than=outer tubular wall16. {Fig 8 illustrates a cap that is formed from two polyethylene com ositions to obtain a'c'onstru'ctionhavin'g the indicated properties and characteristics. -ln,-Fig. '8, inner wall =17 i's first tor-med from the softeri'p'olyethylene-composition while -outer wall 16, annular bead 1-9, the top wall :15

From'the foregoing, it is believed that construction-and advantages of the bottle cap of this invention and the method of making the same will be readily comprehended by spers on'sskilled in -the art, without further description. It is to be understood, howver that theinventionis not to be limited to the exact details -describedand-shown hereinjbut is to be accorded the full scope and protection of theappende'd claims.

Iclaimz. V V

1. In a frangible cap whi6h= -is adapted to seal a container, such as a bottle, having an outer beadf at its discharge end, a top wall, an outer tubular'wall depending iron; the top wall "and open at its lower end an inner tubular wall depending from the top'wall and open at its lowerend, said inner wall being spaced -from and substantially coaxialwith theo'uter 'wall 'the lo wer end of the outer wall including arrinwardly extending annular bead,-said lower end having fofmed thereina plui rality of circumterent'ially-spaeedblind recesses that exribs 18 are all made of a stiffen-less pliable poly-' I Reference is next had to Figs. '9 and =10' which illustrate molding apparatus for forming-the cap of -Fig. V molding apparatus includes a. press comprising 'a lower-platen 25 which c'arries a-bed:plate 26. Mounted on the bed'zplate' is a mold -27 having a plurality of -'g'rooy es,-namely an annular -to'p groove zficorresponding ingsize and' config'uration'to inner wall -17,--a1plurality of 'radial top grooves -29 corresponding "inriufiiben -size and configuration to ribs 18, and *an annular-side groove 3t! corresponding in size-and configuration to head 19.

saidgplzitegand communicatingat its central ;part with :tube;33.. iWith-the ip'arts' disposed in the-relationship as tend upwardly tromjits lower surfaee,isaid cap "being 7 adaptedto be operative lyiconnected to the bottle with the top wall positioned over and across the'disch'arge end of'the bottle, the inner wall disposed in and forming intimate contact with the inner surface "of the discharge end of the bottle, the outer walleiicircling-thebottle outer bead and the annular bead forming;-continuous intimate contact with the bottle outer bead, the parts ojfthe cap which define the {recesses constituting relatively weak regions-that areadapted to be'torn'in thecourse offpryin'g the cap iromlhe bottle.

' :2- ln a iralngible cap whieh isadapted to sealla con- 7 7 tainer, such as a bottle, havingian outer'bead 'at its dischargeend, a topewallyanlouter tubular jwall depending 'fromthe top' wall and openat its lower end. :an inner tubular walldepending -fr' om' .thetop Welland open at its lower end, said :irinefWllbeingQSpa'ddTrent and 7 andinner walls-being imperforate, thedower end of the.

substantially-coaxial withihe-outr wan, said top,.6uter outer wallincludingan inwardlyrprojecting annularlbead,

. said lower 7 end having formed therein alplurality of circumferentially spacedblindtrecesses that 'extendupwar'dly from its lower :surfacie, s'aid caip being adapted to be operatively connected to the bottle with the top wall positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the inwardly projecting bead forming continuous intimate contact with the bottle outer bead, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

3. In a frangible cap which is adapted to seal a can tainer, such as a bottle, having an outer bead at its discharge end, a top wall, an outer tubular wall depending from the top wall and open at its lower end, an inner tubular wall depending from the top wall and open at its lower end, said inner wall being spaced from and substantially coaxial with the outer wall, the lower end of the outer wall including an inwardly projecting annular head, said lower end having formed therein a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface, that extend into the outer wall and that terminate inwardly of the outer surface of the outer wall, said cap being adapted to be operatively connected to the bottle with the top wall positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the inwardly projecting bead forming continuous intimate contact with the bottle outer bead, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

4. In a frangible cap which is adapted to seal a container, such as a bottle, having an outer head at its discharge end, a top wall, an outer tubular wall depending from the top wall and open at its lower end, an inner tubular wall depending from the top wall and open at its lower end, said inner wall being spaced from and substantially coaxial with the outer wall, said top, outer and inner walls being imperforate, the lower end of the outer wall including an inwardly projecting annular head, said lower end having formed therein a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface, that extend into the outer wall and that terminate inwardly of the outer surface of the outer wall, said cap being adapted to be operatively connected to the bottle with the top wall positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the annular bead forming continuous intimate contact with the bottle outer head, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

5. In a frangible cap which is adapted to seal a container, such as a bottle, having an outer bead at its discharge end, a top wall, an outer tubular wall depending from the top wall and open at its lower end, an inner tubular wall depending from the top wall and open at its lower end, said inner wall being spaced from and substantially coaxial with the outer wall, a plurality of stiffening ribs depending from the top wall and positioned wholly within the inner wall, the lower end of the outer wall including an inwardly extending annular bead, said lower end having formed therein a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface, said cap being adapted to be operatively connected to the bottle with the top wall positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the annular bead forming continuous intimate contact with the bottle outer bead, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

6. In a frangible cap which is adapted to seal a con tainer, such as a bottle, having an outer head at its discharge end, a top wall, an outer tubular Wall depending from the top wall and open at its lower end, an inner tubular wall depending from the top wall and open at its lower end, said inner wall being spaced from and substantially coaxial with the outer wall, said top, outer and inner walls being imperforate, a plurality of stilfening ribs depending from the top wall and positioned wholly within the inner wall, the lower end of the outer well including an inwardly projecting annular head, said lower end having formed therein a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface, that extend into the outer wall and that terminate inwardly of the outer surface of the outer wall, said cap being adapted to be operatively connected to the bottle with the top wall positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the annular bead forming continuous intimate contact with the bottle outer bead, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

7. in a one-piece thermoplastic, flexible, frangible cap which is adapted to seal a container, such as a bottle, having an outer bead at its discharge end, a top wall, an outer tubular Wall depending from the top wall and open at its lower end, an inner tubular wall depending from the top wall and open at its lower end, said inner wall comprising a material that is more pliable than the material of the outer wall and being spaced from and substantially coaxial with the outer wall, said top, outer and inner walls being imperforate, a plurality of stiffening ribs, depending from the top wall and positioned wholly within the inner wall, the lower end of the outer well including an inwardly projecting annular head, said lower end having formed therein a plurality of circumferentially spaced blind recesses that extend upwardly from its lower surface, that extend into the outer wall and that terminate inwardly of the outer surface of the outer well, said cap being adapted to be operatively connected to the bottle with the top well positioned over and across the discharge end of the bottle, the inner wall disposed in and forming intimate contact with the inner surface of the discharge end of the bottle, the outer wall encircling the bottle outer bead and the annular bead forming continuous intimate contact with the bottle outer bead, the parts of the cap which define the recesses constituting relatively weak regions that are adapted to be torn in the course of prying the cap from the bottle.

References Cited in the file of this patent UNiT ED STATES PATENTS Woydatt et al. Dec. 4, 1956