Patent Publication Number: US-6338425-B1

Title: Dispensing closure

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to dispensing closures for containers, and more particularly, to such closures which include a self-sealing spout, and also which may include a control member or overcap for operation of the spout. 
     2. Description of the Prior Art 
     Twist top and pull/push closures for containers are known in which a cap or spout with a central aperture cooperates with an upstanding post formed on a base to open or close the closure. The base is affixed to the mouth of a product container, such as a water bottle, and when the cap is moved, such as by twisting or pulling relative to the base, the post on the base is withdrawn from engagement with the aperture in the cap to permit product, such as water, in the container to be dispensed by passing through the aperture. After dispensing of the product is completed, the cap is returned to its closed position by reverse-twisting or pushing on the cap to re-engage the post in the aperture and thereby close the closure and prevent product from being dispensed from the container. 
     Examples of twist top and pull/push closures of the type referred to above are shown in the following U.S. patents which are owned by a wholly-owned subsidiary of the assignee of the present application: U.S. Pat. No. 5,328,063 issued Jul. 12, 1994 entitled “Venting Closure Cap”; U.S. Pat. No. 4,967,941 issued Nov. 6, 1990 entitled “Twist Lock Adjustable Metering Closure Cap.” The disclosures of said two patents which illustrate structure and operational features of examples of twist top and pull/push closures hereby are incorporated herein by reference. 
     Attention also is directed to copending application Ser. No. 09/415,797, filed Oct. 11, 1999, entitled “Universal Base Pull/Push-Twist Closure”, owned by the same assignee as the assignee of the present application, and disclosing a base similar to the base of the present invention. The disclosure of said copending application hereby is incorporated herein by reference. 
     The disclosure of U.S. Pat. No. 5,328,063 shows a pull/push closure in which a cap is mounted on its associated base and the closure is opened/closed by assertion of a pull/push force upon the cap with respect to the base. The disclosure of U.S. Pat. No. 4,967,941 shows a twist type closure in which the cap rides on a ramp formed in the associated base when the cap is twisted with respect to the base to effect the open/close operation of the cap with respect to the base. The disclosure of application Ser. No. 09/415,797 shows both pull/push and twist type closures which are movable to open/closed portions by either twisting or pull/push operation. 
     Interengagement between the aperture in the cap and the post formed on the base is intended to seal the closure and prevent product from being dispensed or escaping from the container on which the base is affixed. In instances where such closure are installed on liquid containers which retain a carbonated beverage product, such as carbonated water, it is desiralbe to incorporate a seal between the cap and the base which will prevent escape of the gas contained in such carbonated product for a maximum time period. Seal constructions of prior art closures have not been as successful as desired in preventing escape of carbonation gas from containers which retain such products so as to increase shelf life and to prevent such products from becoming stale. The seal construction of the present invention reduces the amount of torque required to open and close the closure. The seal construction also allows for greater interferences between the orifice in the cap and an interengaging plug on the base post which enables the sealing of greater pressure in the container which was not possible in prior art structures. Such greater interferences provide wider tolerance range to improve high volume manufacturing feasibility. 
     Additionally, it is desirable to provide an overcap component for such closures which protects the cap or spout from germ, dust and/or dirt contamination. Such an overcap also can provide a tamper-evident feature for such closures. An example of such an overcap is shown in U.S. Pat. No. 5,829,611 issued Nov. 3, 1998 entitled “Tamper-Evident Overcap,” owned by a wholly-owned subsidiary of the Assignee of the present application. The disclosure of said patent hereby is incorporated herein by reference. In instances where such an overcap is used with a closure for a container retaining a carbonated beverage, the overcap serves an additional function of preventing carbonated liquid from spraying the user upon initial opening of the container. Further, it is desirable to provide an overcap which is capable of moving the cap over which the overcap is positioned relative to the base without the necessity for the user to touch the spout with his fingers, as in prior art constructions. For this purpose, it is desirable to provide an overcap which conforms in shape to the cap which is positioned under the overcap so as to facilitate movement of the cap to its open position upon movement of the overcap. 
     SUMMARY OF THE INVENTION 
     The invention is characterized by a closure including a cap movable with respect to its associated base between a closed sealed position and an open unsealed position in which product can be dispensed from a container upon which the base is secured. A generally U-shaped flange formed of resilient material such as plastic is positioned about the peripheral opening of an aperture formed in the cap which moves adjacent to a plug formed on the upstanding post of the associated base of the closure. One end of the U-shaped flange is secured to the aperture opening and the other end forms a terminal free end. The flange is in interference engagement with the plug when the cap is moved to its closed position. When so engaged, the terminal free end of the flange is moved into compression engagement with the wall of the plug. Also, the entire flange is moved to be spaced a greater circumferential distance about the plug than when the cap was in open or unsealed disposition with respect to the plug. Such spacing of the resilient flange adds or contributes to the sealing pressure of the flange about the plug. 
     The invention also is characterized, alternately, by a removable overcap positioned upon said base and disposed over the cap. The overcap preferably has an interior configuration which conforms to the exterior configuration of the cap to facilitate movement of the cap to open unsealed position without touching of the cap when the overcap is moved. 
     Various objects and advantages of the invention will become apparent in accordance with the above and ensuing disclosure in which the preferred embodiments are described in detail in the specification and illustrated in the accompanying drawings. It is contemplated that minor variations may occur to persons skilled in the art without departing from the scope or sacrificing any of the advantages of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing the closure of the invention with the cap illustrated in closed position with respect to its associated base; 
     FIG. 2 is a perspective view similar to that of FIG. 1 but illustrating the cap moved to its open position; 
     FIG. 3 is a top plan view of the closure of the invention; 
     FIG. 4 is a sectional view taken along the line  4 — 4  in FIG. 3, in the direction indicated generally; 
     FIG. 5 is a perspective longitudinal sectional view of the closure with the cap illustrated in its open position; 
     FIG. 6 is an enlarged fragmentary sectional view of the upper portion of the cap when disposed in its fully open position; 
     FIG. 7 is an enlarged fragmentary view similar to that of FIG. 6, but showing the cap moved toward its closed position; 
     FIG. 8 is an enlarged fragmentary sectional view similar to that of FIGS.  6  and  7 ,but showing the cap moved to a partially closed position; 
     FIG. 9 is an enlarged fragmentary sectional view similar to that of FIGS. 6-8, but showing the cap moved to its fully closed position; 
     FIG. 10 is a bottom perspective view of the cap of the invention; 
     FIG. 11 is a bottom plan view of the cap of the invention; 
     FIG. 12 is a perspective view of the overcap of the invention; 
     FIG. 13 is a perspective view illustrating the closure of the invention with the overcap of FIG. 12 shown installed over the cap, the cap being shown in closed position with respect to its associated base; 
     FIG. 14 is a perspective view similar to that of FIG. 13, but illustrating the cap and overcap moved to the open position of the cap; 
     FIG. 15 is a sectional view taken along the line  15 — 15  of FIG. 13, in the direction indicated generally; and 
     FIG. 16 is a sectional view taken along the line  16 — 16  of FIG. 14, in the direction indicated generally. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1-11, the closure  10 , preferably formed of an appropriate food-compatible plastic material, comprises base  12  and spout or cap  14 . The preferred form of closure  10  is illustrated as a twist top closure, but other closures, such as pull/push closures, may function within the intended scope of the invention. 
     The base  12  is adapted for attachment to a container top (not shown) in known manner, such as by screw threads  18  formed on the inner surface of the cylindrical side wall  20  of the base which mate with like threads on a container neck. The base also includes a top panel  22  extending inwardly from the base side wall  20 . A vertically elongate post  24 , integrally molded with the top panel  22 , extends vertically therefrom coaxial with and inwardly spaced from the surrounding wall  20 . The post  24  has a cylindrical side wall  26  defining a product flow passage  28  vertically therethrough and opening through the top panel  22 . The post  24 , having a radial dimension less than that of base side wall  20 , forms a concentric channel  30  about the post and between the post wall  26  and a flange  32  defined from the upper portion of the base side wall  20  peripherally thereabout and extending upwardly from the base top panel  22 . The external surface of the post wall  26  includes a lower portion  34  and an upper portion  36  with an annular abutment surface or shoulder  38  formed therebetween. 
     An annular sealing rib  40  is formed proximate to the upper terminal end of the upper portion  36  of the post  24  and extends circumferentially about the external surface of the post. A sealing plug  42  is centrally positioned within the upper terminal end portion of the post  24  and projects vertically therefrom in radially inwardly spaced relation to the post wall. The plug is supported by a support spider formed of spaced radially extending spokes  44  (see FIG. 5) which minimally restrict the flow of discharging product annularly about the plug  42  when cap  14  is in its open position, as will be described subsequently. The lower portion  34  of the post wall is formed with a pair of diametrically opposed helical groove channels  46 . 
     Twist cap  14  is formed with an upstanding wall  62  having a top platform  64  with aperture  66  therethrough extending between upper surface  103  and lower surface  105  of platform  64 , and a lower terminal end  68  with circumferentially projecting flange  70  formed proximate thereto. The external surface  72  of cap  14  preferably is of generally oval or elliptical configuration with relatively flat side walls  74 ,  76  to facilitate grasping of the cap by a user to effect a twist motion thereto. 
     The inner surface  78  of cap  14  is adapted for cooperative engagement upon post  24  of base  12 , and is formed with a pair of oppositely disposed, radially inwardly projecting drive threads  79 ,  80 . Respective drive threads  79 ,  80  are equally spaced around the cap circumference from each other, and are matingly engageable within respective helical grooved channels  46  formed on post  24 . Twisting of cap  14  causes threads  79 ,  80  to ride in channels  46  and thereby draw the cap downwardly upon post  24  to the closed position of cap  14  shown in FIGS. 1,  4  and  9 . In said closed position, sealing plug  42  of post  24  engages within aperture  66  to seal the aperture and prevent dispensing of product therethrough. 
     Opening of twist cap  14  is accomplished by counter-turning same on base  12  thereby causing threads  79 ,  80  to reverse-ride in channels  46  and move the cap upwardly on post  24  to the opened position shown in FIGS. 2,  5  and  6 . When cap  14  is moved to its opened position, plug  42  is withdrawn from engagement with aperture  66 , and product thereby may be dispensed from the container through the passageway  28  in base  12  and out aperture  66  in cap  14 . 
     Annular sealing flange  100  is formed on aperture  66  in order to enhance the sealing characteristics between plug  42  and its engagement within aperture  66  when cap  14  is moved to its closed position. Flange  100  is of generally U-shaped configuration and includes a first leg portion  102  which is formed integral with and extends downwardly from the circumferential periphery  104  of aperture  66  and below the lower surface  105  of top platform  64  of cap  14 . A second leg portion  106  is connected to first leg portion  102  at a connecting portion  108  and is reverse-bent with respect to first leg portion  102  and terminates at free end  110 . A crease  135  is formed above connecting portion  108  between legs  102  and  106 . 
     As best seen in FIGS. 6-9, the dimensional proportions of aperture  66  and sealing flange  100  are such that, prior to engagement of flange  100  with plug  42  (FIGS.  6  and  7 ), leg  106  interferes with the external surface  120  of plug  42 . When cap  14  is moved toward its closed position upon base  12  (FIGS.  7  and  8 ), leg  106  is moved into interference engagement with surface  120  and is forced radially away from surface  120  (see arrow F 1  in FIG.  8 ), but is maintained in compression engagement therewith by reason of the resilient nature of the plastic material from which closure  10  is formed. Simultaneously, leg  102  also is forced radially away from surface  120  (see arrow F 2  in FIG.  8 ), such that both legs  102  and  106  maintain compression engagement against surface  120 . 
     When cap  14  is moved to its completely closed position on base  12  (FIG.  9 ), leg  106  is in full engagement with surface  120  and complete compression is achieved between the sealing flange  100  and the plug  42 . Also, the leg  102  is moved to be spaced a greater circumferential distance about plug  42  than when cap  14  was in its open or unsealed position (FIGS. 6 and 7) with respect to the plug. Such spacing of the resilient flange  100  adds to or contributes to the sealing pressure of the flange about the plug. A projection line X—X between FIGS. 7,  8  and  9  shows the relative movement of legs  102 ,  106  with respect to surface  120  of plug  42  as the cap  14  is moved from its open to closed position. 
     When cap  14  is moved to its fully closed position shown in FIG. 9, the seal flange  100  conforms to surface  120  of plug  42  to maintain contact therebetween. Arrows P indicate the forces of the contents of the container upon which closure  10  is positioned to maintain constant sealing pressure against flange  100 . As the sealing pressure of the container contents increases, the sealing forces P increase. The external channel above crease  135  between legs  102  and  106  is exposed to atmosphere which permits the legs  102 ,  106  to conform to surface  120  with minimized effect from the pressure of the contents of the container. The pressure forces are transmitted through connecting portion  108  to contribute to the forces from the container contents which reinforce leg  106  and maintain the seal as pressures increase. 
     Optimal performance of pressure seal  100  is achieved when the proportional dimensions of legs  102  and  106  are as follows (see FIG.  9 ): 
     Thickness A of leg  102  is less than or equal to the distance B between lower surface  105  of cap platform  64  and crease  135  proximate connecting portion  108  between legs  102  and  106 . 
     Thickness A of leg  102  is less than the thickness C of platform  64  between upper surface  103  and lower surface  105 . 
     The length E of leg  106  between free end  110  and the lower surface  140  of connecting portion  108  is more than the combined dimension B and D, where D is the distance between crease  135  and lower surface  140  of connecting portion  108 . 
     The distance D is less than or equal to the thickness A. 
     In tests over an extended time period of the closure  10  of the invention having sealing flange  100  in comparison to prior art closures which do not include such a sealing flange, the prior art closures maintained a 20 psi pressure in only 60% of the samples; closures of the invention including the sealing flange  100  maintained such pressure in 97% of the samples, thus demonstrating a substantially improved seal. Prior art closures performed at a 15% success rate holding at or above 10 psi; closures of the invention successfully hold 15 psi or above at a success rate of 89%. Based upon these tests, the closure of the invention with sealing flange  100  averaged a six-fold performance advantage over the prior art closures. 
     An additional and alternate feature of the invention is illustrated in FIGS. 12-16 of the drawings. The same closure  10  shown in FIGS. 1-11 is shown in FIGS. 12-16, and therefore, identical reference numbers are used to identify the same parts with reference thereto. FIGS. 12-16 illustrate closure  10  with overcap  200  illustrated in association therewith. Although overcap  200  is shown in association with closure  10 , it is to be understood that the overcap can be used with other types of closures within the contemplation of the present invention. 
     Base  12  is provided with circumferential channel  190  disposed concentrically with respect to channel  30  and spaced radially outwardly with respect thereto. 
     Overcap  200  includes a domed top portion  210  having a lower edge  212  connected by frangible connections  214  to circumferential skirt  216  which is permanently retained by the force-fit within channel  190 . The interior surface configuration  220  of domed portion  210  is chosen to be substantially conforming to the exterior surface configuration  222  of closure  10 . In the preferred embodiment illustrated, this configuration is generally oval or elliptical at the extreme upper end  224  thereof and also in the transitional area  226  above a generally cylindrical lower portion  228 . Although a specific generally elliptical configuration is shown in the drawings, it is to be understood that other configurations are within the scope and contemplation of the invention. 
     When overcap  200  is installed upon closure  10 , the closure is in its closed position illustrated in FIGS. 13 and 15. When it is desired to move cap  14  to its open position with respect to base  12 , a twisting force is asserted on the overcap external surface. By reason of the conforming interior surface configuration  220  of over cap  200  to the exterior surface configuration  222  of cap  14 , twisting of the overcap results also in twisting of cap  14 . Upon such twisting movement, frangible connections  214  are severed and the overcap moves the cap  14  upwardly to its open position shown in FIGS. 14 and 16. Reverse operation can be effected to move the cap to its closed position. 
     The overcap  200  can be formed of opaque, translucent or transparent material, the latter being illustrated in the drawings. The illustrated construction is such that the closure can be opened without touching the cap. Also, the overcap redirects any leakage or spray from the container on which the closure is positioned so as to minimize contact by the container contents to the user. 
     Other configurations and variations in the structure, arrangement and size of the various parts may occur to those skilled in the art without department from the spirit or circumventing the scope of the invention as set forth in the appended claims. For example, the overcap may be provided with an interior projecting flange  250  to engage under the exterior projecting flange  70  formed on the cap (see FIGS. 13 and 14) to retain the overcap on the closure after the overcap has been initially opened and thereby to prevent same from inadvertently falling off the closure when it is re-positioned after initial opening.