US3263851A

US3263851A - Container closure

Info

Publication number: US3263851A
Application number: US367419A
Authority: US
Inventors: Grimsley Arvid Kjellsen
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1964-05-14
Filing date: 1964-05-14
Publication date: 1966-08-02
Anticipated expiration: 1983-08-02
Also published as: GB1033037A; FI41717B; FI41717C; DK108612C

Description

Aug. 2, 1966 A. K. GRIMSLEY CONTAINER CLOSURE Filed May 14, 1964 INVENTOR.

14E V/D AJELLSE/V @P/MSLE) United States Patent 3,263,851 CONTAINER CLOSURE Arvid Kjellsen Grimsley, Rockaway, N.J., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed May 14, 1964, Ser. No. 367,419 6 Claims. (Cl. 215-74) This invention relates to closures for containers such as collapsible tubes, plastic bottles and the like, and is particularly directed to an improved captive cap type closure wherein the cap and container neck which comprise the closure are at all times positively engaged and are prevented from accidental dislodgment due to excessive twisting.

Captive cap closures are known wherein the threads of the cap remain engaged with the threads of the container neck when the cap is rotated to its open position. In such arrangements, cooperable beads or similar stop elements on the cap and neck come into locking engagement both to limit the outward displacement of the cap and, supposedly, to prevent its further rotation. A disadvantage of closures of this type is in the fact that the unwary user of the container often applies excessive twist or rotation to the cap beyond that which is necessary to fully open the closure. This often results in serious damage to the closure, such as thread stripping, which may render it useless, or, the locking beads may be forced over each other, thereby permitting the cap to become completely dislodged from the neck.

Captive closures also are known which seek to avoid the above problems. One such arrangement provides for total disengagement of the neck and cap threads in the open position of the closure so that the cap, while still retained on the neck by the displacement limiting means, is freely rotatable. A disadvantage of this construction is in the need for re-engaging the threads to close the cap. This requires the user to hunt or blindly seek proper reengagement of the threads by trial and error, and frequently leads to thread cocking, damage to the closure and improper sealing.

A primary object of my present invention is to provide a captive cap closure which both maintains the threads in position for positive re-engagement at all times and enables continued rotation of the cap in its fully open position without dislodgement.

Another object of this invention is to provide a captive cap closure construction wherein the cap and neck members comprising the closure are relatively oonfigurated and dimensioned so that the cooperating threads on the cap and neck are adapted to assume a position of minimum engagement ensuring positive re-engagement at all times and at the same time permit additional relative rotation without dislodgement of the cap.

These and other objects and advantages of this invention and their manner of accomplishment will be apparent from the following description which, taken in connection with the accompanying drawing and appended claims, discloses a preferred embodiment thereof.

Referring to the drawing:

FIGURE 1 is a vertical view, partly in section, of the closure of this invention in closed position;

FIGURE 2 is an enlarged vertical sectional view of the closure in open position;

FIGURE 3 is a transverse sectional view taken substantially along lines 3-3 of FIGURE 2;

FIGURE 4 is a fragmentary sectional view taken substantially along lines 44 of FIGURE 3.

FIGURE 5 is an enlarged fragmentary sectional view depicting the relationship of the closure threads as they begin to override upon continued rotation of the closure cap when in full open position.

3,263,851 Patented August 2, 1966 FIGURE 6 is an enlarged fragmentary sectional view, similar to FIGURE 4, depicting the closure threads being deformed and about to snap over each other after a partial turn of the closure cap beyond the circumferential position depicted in FIGURE 5.

The drawing illustrates a form of closure having its internal or neck element formed as an integral part of a container 10, such as a plastic bottle or collapsible tube, although the closure could be a separate unit adapted to be assembled to the discharge end of the container. As shown, the closure comprises an internal neck generally designated 11 and an external captive cap generally designated 24 threadably engaged with the neck, the two members being permanently locked together by cooperating displacement limiting means adapted to interlock in the open position of the closure.

Neck 11 has an interior passage 12 communicating with the interior of container 10, and includes at its upper end a central closure plug 13 integrally supported on radiating arms 14 connected to the inner wall of the neck, which arms are circumferentially spaced apart to provide discharge apertures 15 surrounding plug 13. The peripheral surface of the plug may be tapered as at 16 and is adapted to seat within an aperture of like configuration in cap 24.

The lower end of neck 11 adjacent the container 10 is in the form of a heavy annular section 17 and is formed on its exterior surface with a helical thread 18, the armate length of which preferably is aboue one and one-half turns. The upper or lead-in surface 18 of thread 18 is formed at a slightly less than 45 angle to the surface of neck section 17, whereas the lower or lead-out surface 18 of the thread is formed slightly less than perpendicular to this surface. The terminal or lead-in end of thread 18 has the form of a rounded run-out segment 18:: which extends for a short arcuate distance of the thread length at its terminal end.

The upper end of neck 11 is formed with an annular peripheral groove 20 of predetermined height and an annular peripheral head 21 of predetermined diameter defining the upper end wall of groove 20. The lower end of the groove is defined by a perpendicular wall 22 disposed a predetermined distance above thread 18. The upper surface 23 of the neck is formed with a slightly curved contour to provide sealing engagement with the captive cap 24, next to be described.

Cap 24 comprises an upper dome-shaped roof or wall 25 having a central tapered aperture 26 adapted to sealingly engage plug 13 of the neck, a lower annular portion 27 having an internal helical thread 28 formed integrally therewith, and an intermediate annular portion 29 having a smooth interior wall 30 which sealingly engages bead 21 on the neck above an interior annular head 31 which is adapted to move in neck groove 20 and abut against the lower surface of head 21 to limit the upper displacement of the cap 24 when the latter is rotated to open position.

Cap thread 28 is of similar configuration to neck thread 18, being provided with a lower or lead-in surface 28 inclined at an angle less than 45 to the axis of the cap, an upper or lead-out surface 28 slightly less than perpendicular to the cap axis, and a rounded, terminal lead-in segment 28a extending a short arcuate length of the thread at the terminal end. The arcuate length of cap thread may but need not be the same as that of neck thread 18.

To assemble cap 24 on neck 11 of the container, internal cap bead 31 is forced down and deformed over neck head 21 while at the

same time threads

18 and 28 are brought into the readily engageable position shown in FIGURE 4. This is made possible by the fact that neck 11 and/ or cap 24 are made of a resilient and deformable material, examples of which are polyethylene, polypropylene, polyvinyl chloride, polystyrene or other types of synthetic resins. It is not necessary that both the neck and cap be of the same material or possess the same degree of deformability and resiliency, so long as the relative dimensions and resiliency and deformability characteristics are such as to provide the intended func tioning. For example, cap 24 may be of a somewhat rigid t-hermosetting material and neck 11 may be of a relatively softer and more resilient thermoplastic material, or vice versa. Also, it is possible that one or the other of these two members could be metal having very low de'formability, in which case the other member would be of a material possessing the requisite resiliency and deformability to permit the desired assembly and functionmg.

When the closure is assembled and fully closed, as illustrated in FIGURE 1,

threads

18 and 28 arein a position of maximum engagement with internal cap bead 31 resting in sealed engagement against the bottom wall 22 of neck groove 20. In this position, the contoured inner surface of cap roof 25 also tightly seals against end surface 23 of the neck and tapered aperture 26 seals about tapered plug 16, thus providing a completely fluidtight closure sealed at three places above the threads.

In the open position of the closure, as illustrated in FIGURE 2,

threads

18 and 28 are in a position of minimum engagement. By the expression minimum engagement is meant that the neck and cap threads are either not completely disengaged or that the threads assume a relative position where their terminal ends 18a and 28a, respectively, are substantially circumferentially aligned (FIGURES 3 and 4), by reason of cap bead 31 coming into locking engagement with neck bead 21 above the threads. This relationship is a function of the spacing of the displacement limiting beads 21 and 31 above the threads as well as the arcuate length and pitch configuration of the threads themselves. As best illustrated in FIGURE 4, terminal end 28a of the cap thread is restrained from further upward axial'movement by cap bead 31 abutting against neck bead 21. At the same time, cap thread 28 is held down tightly against a lower segment of neck thread 18. Thus, the threads are retained at all times-in engaged contact for quick re-engagement when it is desired to reclose the closure. If desired, the minimum engagement of

threads

18 and 28 may be as much as a quarter of a turn, for example, in which case terminal ends 18a and 2811 would be circumferentially displaced approximately 90 rather than in alignment as illustrated.

While sufficiently deformable to permit cap 24 to be forced onto neck 11 in initial assembly of the closure, beads 21 and 31 have the requisite strength to resist deformation in the open position of the closure to prevent its disassembly. That is, the depth and thickness dimensions of beads 21 and 31' and the fact that they are engageable for the full circumference of the closure give them a resistance to deformation upon the opening of the closure to the position of minimum thread engagement substantially in excess of the resistance to deforma-' tion of

threads

18 and 28 to each other, whether slightly engaged or in the position shown in FIGURES 3 and 4. Thus, the tendency is for these threads to yield and deform first, in the event the user attempts to apply excessive twist to cap 24, so that they override and remain in position for quick engagement at all times. This overriding action is illustrated in FIGURES and 6, first showing cap thread 28 just beginning to override neck thread 18 when the cap is turned in the direction of the arrow and then depicting the relative deformation of these threads upon continued turning of the cap just before they snap over each other to remain engaged. It will be seen that this overriding action is facilitated by the angular relation of the lead-in

surfaces

18 and 28 of these threads, plus the fact that the

rounded end portions

18a and 28a of the threads provide even less resistance to deformation. Accordingly, continued rotation of cap 24 on neck 11 beyond that position illustrated in FIG- URES 3 and 4 will not permit thread end segment 28a to move up and slip out of engageable position due to the restraining force of beads 21 and 31; instead, the threads will be caused to override and assume their position for quick engagement at all times regardless of the amount of excessive twist applied by the user.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction, and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the'form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A closure for a container comprising a hollow neck of resilient deformable thermoplastic material having a top central closure plug and discharge passages surrounding said plug, said neck having integral exterior threads and an annular integral bead spaced above said threads a predetermined distance, and a captive cap having a central aperture cooperable with said plug on said neck, interior integral threads cooperable with the exterior threads on said neck and an interior integral annular bead spaced above said cap threads a predetermined distance cooperable with said neck bead to limit outward displacement of said cap, said threads being in a position of maxim-um engagement when said cap is turned down on said neck with said plug sealing said aperture and in a position of minimum engagement when said cap is turned up on said neck with said beads in interlocked engagement so that said threads engage each other for a small portion of their respective lengths, said beads and said threads being configurated and relatively dimensioned so that said threads in said position of minimum engagement deform and override each other and remain in said position of minimum engagement to permit continued rotation of said cap in its open position without disengaging said beads and said cap from said neck.

2. The closure of claim 1 wherein the engagement of said threads in their position of minimum engagement is approximately one quarter of a turn.

3. The closure of claim 1 wherein the'terminal lead-in ends of said threads are substantially circumferentially aligned at the time the beads initially engage upon opening of the cap.

4. The closure of claim 1 wherein the lead-in surfaces of said threads are slightly inclined to the axis of said neck and the lead-out surfaces are of substantially greater inclination.

5. The closure of claim 1 wherein the lead-in ends of said threads are rounded. 6. The closure of claim 1 including an annular groove between the threads and bead on said neck, said head on said cap riding in said groove and being engageable on the lower wall of said groove in closed position to limit inward displacement of said cap.

References Cited by the Examiner UNITED STATES PATENTS 1,920,199 8/1933 Jesnig 222-521 2,060,622 11/1936 Jones 2l574 2,542,350 2/1951 Paulsen 222-499 2,759,643 8/1956 Dahlin 222--521 THERON E. CONDON, Primary Examiner.

v JOSEPH R. LECLAIR, Examiner.

Claims

1. A CLOSURE FOR A CONTAINER COMPRISING A HOLLOW NECK OF RESILIENT DEFORMABLE THERMOPLASTIC MATERIAL HAVING A TOP CENTRAL CLOSURE PLUG AND DISCHARGE PASSAGES SURROUNDING SAID PLUG SAID NECK HAVING INTEGRAL EXTERIOR THREADS AND AN ANNULAR INTEGRAL BEAD SPACED ABOVE SAID THREADS A PREDETERMINED DISTANCE, AND A CAPTIVE CAP HAVING A CENTRAL APERTURE COOPERABLE WITH SAID PLUG ON SAID NECK, INTERIOR INTEGRAL THREADS COOPERABLE WITH THE EXTERIOR THREADS ON SAID NECK AND AN INTERIOR INTEGRAL ANNULAR BEAD SPACED ABOVE SAID CAP THREADS A PREDETERMINED DISTANCE COOPERABLE WITH SAID NECK BEAD TO LIMIT OUTWARD DISPLACEMENT OF SAID CAP, SAID THREADS BEING IN A POSITION OF MAXIMUM ENGAGEMENT WHEN SAID CAP IS TURNED DOWN ON SAID NECK WITH SAID PLUG SEALING SAID APERTURE AND IN A POSITION OF MINIMUM ENGAGEMENT WHEN SAID CAP IS TURNED UP ON SAID NECK WITH SAID BEADS IN INTERLOCKED ENGAGEMENT SO THAT SAID THREADS ENGAGE EACH OTHER FOR A SMALL PORTION OF THEIR RESPECTIVE LENGTHS, SAID BEADS AND SAID THREADS BEING CONFIGURATED AND RELATIVELY DIMENSIONED SO THAT SAID THREADS IN SAID POSITION OF MINIMUM ENGAGEMENT DEFORM AND OVERRIDE EACH OTHER AND REMAIN IN SAID POSITION OF MINIMUM ENGAGEMENT TO PERMIT CONTINUED ROTATION OF SAID CAP IN ITS OPEN POSITION WITHOUT DISENGAGING SAID BEADS AND SAID CAP FROM SAID NECK.