Abstract:
An improved snap-on/twist off closure which is very durable. The invention is also directed to a package comprising the closure, e.g., a bottle in combination with the closure. The closure includes an upper wall defining an opening and a cylindrical snap on pipe depending from the upper wall. The pipe includes threads designed to mate with external threads on a neck of the bottle. The threads on the pipe and threads on the neck of the bottle pass over each other when the closure is snapped onto the bottle during manufacture. The pipe includes a resistance recess and a guidance recess. The resistance recess and the guidance recess accommodate a forcing element on a shoulder of the bottle and permit unscrewing of the closure

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Numerous personal care products are sold in plastic bottles. Examples of such products are body washes and shampoos. While dispensing of a body wash or hair care product from a bottle is convenient for the consumer, plastic bottles generally are disposed of after one use and sometimes undesirably find their way into landfills. Although plastic bottles are sometimes recycled, both transportation to the recycling facility and recycling itself utilize energy. Accordingly, it would be preferable if the packaging were re-used instead of discarded after a single use. 
         [0002]    While some present commercial bottles could theoretically be re-used by consumers, the ease of doing so generally leaves something to be desired. For instance, it may be difficult for a consumer to remove the closure sufficiently to facilitate access to the body of the bottle. This creates a considerable impediment to the goal of minimization of plastic usage and disposal. Therefore, there has been a need for a bottle having a closure which can readily be removed by the consumer. Moreover, it is important that the consumer be able easily to again secure the closure to the bottle once she has refilled the container. 
         [0003]    Easy consumer access to the interior of the bottle is certainly desirable, but the bottle cannot be designed such that the closure will separate from the bottle too readily. Otherwise, product will be released from the container at inopportune times, such as during transportation. Also, the goal of a readily separable closure must be balanced with a competing goal, namely ease of placing the closure on the bottle during manufacture and attendant minimization of production costs. 
         [0004]    Jackel U.S. Pat. No. 8,365,933 discloses a closure system including a snap-on closure which can be pressed upon a spout wherein two interacting dements are shifted by or over one another due to their flexibility. The closure can only be removed with difficulty in the strictly axial/vertical direction by exerting a certain force, but can be removed by a rotational motion which is significantly easier to perform than the axial removal motion. The closure includes a recess in a cylindrical snap-on pipe which engages with a forcing element on the container shoulder. The sides of the recess are designed so that the gradient at one point on one side is smaller than the gradient at the same point on the other side. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to an improved snap-on/twist off closure which does not suffer from some disadvantages of prior closures. In particular, it is very durable, as can be seen in the standard industry drop test. The invention is also directed to a package comprising the closure, e.g., a bottle in combination with the closure. 
         [0006]    The base of the closure of the invention includes an upper wall defining an opening and a cylindrical snap-on pipe depending from the upper wall and extending vertically/axially to a bottom pipe end. The cylindrical snap-on pipe includes threads on inner wall designed to mate with external threads on a neck of the bottle. The closure base is snap fit onto the bottle neck whereby the thread of the cylindrical snap-on pipe passes over and temporarily locks beneath the thread of the container neck. 
         [0007]    The closure cylindrical snap-on pipe includes at its bottom end at least one resistance recess and at least one guidance recess. The resistance and guidance recesses play roles in the unscrewing of the closure whereby it can be easily removed for refilling. The resistance recess includes opposing first and second walls defined by the cylindrical snap-on pipe and which have gradients wherein the gradient of one of the walls is smaller at east at one point than the gradient on the other wall at a point lying at the same axial/vertical height. 
         [0008]    When the closure is dosed, a forcing element from the container is at east partially accommodated within the resistance recess. The resistance recess wall with the higher gradient contacts the forcing element, which resists turning of the closure in one (non-opening/screwing closed/closure securing) direction, usually the clockwise direction. When the closure is turned in the opposite, or opening/unscrewing/closure removal direction, contact between the gentler gradient of the opposite wall of the resistance recess and the forcing element forces the closure slightly upwardly. During this initial rotation the internal thread on the cylindrical snap-on pipe maintain its/their position below the external thread of the container neck as the closure travels axially upwardly relative to the container neck. The axial motion results from the fact that the threads are angled; the net result of the angled rotational movement is axial movement. Alternatively, the closure may be structured so that with sufficient axial force, e.g., exerted by the consumer, even during the initial rotation once the forcing element is disengaged from the resistance recess, the internal thread on the snap on pipe may pass over the external thread of the container neck to facilitate removal of the closure. 
         [0009]    Upon further turning of the closure in the counterclockwise or unscrewing/opening direction, the forcing element encounters the trailing end of the resistance recess followed by the bottom rim of the snap-on pipe and then by a guidance recess. During rotation of the closure in the unscrewing/opening direction, the guidance recess first extends upwardly from the bottom end to permit lowering of the cylindrical snap-on pipe relative to the container neck while the mating threads on the closure cylindrical snap-on pipe and container neck contact each other. Thereafter, with the cylindrical snap-on pipe and neck threads still in engagement, as the closure is rotated further in the unscrewing/opening/closure removal direction, the guidance recess includes a gradual downward gradient toward the bottom end of the cylindrical snap-on pipe. 
         [0010]    The downward gradient of the guidance recess, and resultant relative upward motion of the closure consistent with the gradients of the matching threads on the container neck and skirt, provides guidance and offers minimal resistance to turning of the closure in the unscrewing/opening direction. The consumer can continue turning the closure with minimal resistance whereby to eventually remove the closure. The presence of the guidance recess also facilitates the reverse process wherein the consumer rotates the closure in the closing, usually clockwise, direction after having refilled the bottle. It is believed that without the guidance recess the bottom of the snap-on pipe would inhibit engagement of the threads upon screwing-on of the closure. 
         [0011]    The closure may include a closing element which contacts and/or covers the top wall of the closure base to seal the closure opening, but which can be removed from the opening to dispense the product. Preferably the closing element remains associated with the closure base when removed to dispense the product, e.g., as the result of a hinge or other attachment. 
         [0012]    The bottom rim of the snap-on pipe extending between the resistance recess and the guidance recess is preferably at least 2 mm and is up to 5 mm, especially from 2 to 4 mm, in length whereby to maximize durability of the closure, including promoting a good, comfortably tight, fit of the closure on the bottle over a prolonged period of use. 
         [0013]    The closure of the invention permits secure placement of a closure on the bottle neck during manufacture yet easy removal of the closure from, and re-application of the closure to, the bottle by the consumer, thereby encouraging removal of the closure to refill the container. The closure is durable, e.g., is resistant to wear and tear. 
         [0014]    It will be apparent that changes such as the directions of screwing/unscrewing and the locations of the threads may require adjustments in the locations and shape of the resistance and guidance recesses. 
         [0015]    For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of preferred embodiments and to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0016]      FIG. 1  is a side elevational view of the bottle and closure of the invention with the closure in cross section 
           [0017]      FIG. 2  is a front elevational view of a bottle of the invention with a portion of the is neck cut away and showing the closure base above it in cross section with the closing cover removed. 
           [0018]      FIG. 3  is a perspective view from above of a closure according to the invention in the open position. 
           [0019]      FIG. 4  is a bottom plan view of the closure of  FIG. 3 . 
           [0020]      FIG. 5  is a side elevation of the package of the invention with the closure partly rotated in the unscrewing/opening/closure removal direction and with portions of the closure broken away to reveal the cylindrical snap-on pipe. 
           [0021]      FIG. 6  is a side elevational view of an upper portion of the container with portions of the closure broken away and with the closure in the fully closed position. 
           [0022]      FIG. 7  is a side elevational view of the closure with portions broken away. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Closure  22  sits on bottle  20  ( FIGS. 5 and 6 ). Closure  22  includes closure base  24  connected to closing cover  26  by hinge  28 , although other possible arrangements will be apparent to one of ordinary skill in the art. Closure base  24  includes generally cylindrical snap-on pipe  30 , best seen in  FIGS. 1 and 2 , depending downwardly from upper wall  25 . Cylindrical snap-on pipe  30  is positioned to engage neck  32  of bottle  20 . The inner wall of cylindrical snap-on pipe  30  includes one or more internal threads  34 , which protrude inwardly. 
         [0024]    Closure base  24  includes a dispensing opening  36  centrally disposed within upper wall  25 . Although opening  36  is illustrated and described as being centrally disposed, it may be off-center if desired. Structure may be provided above and/or below opening  36  to assist with pouring or sealing, such as ring  38 . When closure base  24  is positioned on bottle  20 , opening  36  is in communication with the interior of bottle  20  through the interior of snap-on pipe  30  and exterior closure base wall  23 . Closing cover  26  includes plug  40  to assist in sealing the closure and ultimately the bottle. 
         [0025]    Neck  32  of bottle  20  includes external threaded protrusion  60 . 
         [0026]    As best seen in  FIGS. 5-7 , cylindrical snap-on pipe  30  includes resistance recess  42  extending upwardly from bottom end or rim  43 . Rim  43  typically extends perpendicularly to the downwardly extending axis of the pipe. A second resistance recess  42   a  may be present 180° removed from resistance recess  42 , as seen in  FIG. 1 . Resistance recess  42  includes two walls  44 ,  46  formed in cylindrical snap-on pip,  30 . The shape of walls  44 ,  46  will depend upon the direction which it is desired to have the closure rotate in order to release it from the bottle so that it can be removed. 
         [0027]    Typically, closures are unscrewed/opened/removed by turning counterclockwise, so for the purpose of the present description counterclockwise unscrewing/opening will be assumed. However, it will be apparent that a different direction could be used if desired and the shapes of walls  44 ,  46  and the location of guidance recess  70  will be adjusted accordingly. 
         [0028]    As best seen in  FIG. 6 , when the closure is in the closed position, resistance recess  42  receives at least part of forcing element  50 , which is a protrusion permanently associated with bottle shoulder  80 . 
         [0029]    The trailing resistance recess wall during unscrewing/opening rotation, illustrated as  44  in  FIG. 7 , includes at its lower end  45  a gradient which is more gradual than that of the opposite (leading) recess wall  46 ; the gradient at the lower end of resistance recess wall  46  is more severe or steep. The forcing element  50  also includes two side walls  54 ,  52  of different gradients. 
         [0030]    Starting from the initially closed position shown in  FIG. 6 , if the closure is rotated in the clockwise direction as the consumer turns it, a steep gradient of forcing element side wall  52  faces a steep gradient on resistance recess wall  46  and prevents rotation. On the other hand, upon rotation of the closure in the counterclockwise direction from the initially closed position, side wall  54  of the forcing element having a gentler gradient faces resistance recess wall  44  which has a gentler gradient in its lower half, e.g., at  45 , proximate its base. The effect of this contact between walls of gentler gradients is that, instead of prevention of rotation, which occurs with the steeper gradients, the forcing element  50  forces the walls of the resistance recess and the depending cylindrical snap-on pipe  30  upwardly. 
         [0031]    The smaller, gentler gradient at  45  ( FIG. 7 ) of the resistance recess wall  44  is similar or identical to the gradient of side wall  54  of the forcing element of the container, which faces resistance recess wall  44  during unscrewing/opening. The gradient of wall of  44  at section  45  is within the range of between 10 degrees more and 10 degrees less than that of wall  54 . Thus, if wall  54  is 45 degrees, wall  44  at section  45  is within the range of from 35 degrees to 55 degrees. Each of wall  44  and  54  is within the range of between 30 and 85 degrees. The gradient of wall  44  at section  45  is measured relative to a horizontal line drawn through rim section  56 . The gradient of wall  54  is measured at the point at which it first contacts wall  44  upon rotation and is measured with respect to a horizontal line intersecting the point of contact with wall  44 , the line being parallel to, or coincident with, bottom rim section  56 . 
         [0032]    Further counterclockwise rotation of closure  22  during removal of the closure by the consumer will result in forcing element  50  clearing resistance recess wall  44 , and the top  58  of the forcing element contacting section  56  of bottom rim  43  of the cylindrical snap-on pipe. Upon still further unscrewing/opening, counterclockwise, rotation of closure  22 , top  58  of forcing element  50  encounters guidance recess  70 , seen e.g., in  FIG. 7 . Guidance recess  70  includes an upwardly extending wall  72  at a gradient within is the range of 90 and 135 degrees to a horizontal line drawn through section  56  of the bottom rim and then a downwardly extending wall  74  at a less severe gradient of within the range of 0 to 10 degrees relative to a horizontal line drawn through the intersection  75  of wall  74  and pipe bottom  43 . 
         [0033]    The distance between resistance recess  42  and the guidance recess  70  is measured along bottom rim section  56  from the point at which wall  44  merges with snap on pipe bottom end or rim  43  to the point at which guidance recess wall  70  begins to ascend at the beginning of wall  72 . The distance between the resistance recess and The distance is typically from 2 mm up to 5 mm, especially from 2 mm to 4 mm. 
         [0034]    The presence of the guidance recess in addition to the resistance recess also facilitates rotation of the closure in the opposite, closing, direction, which is generally clockwise. When the closure is rotated in the clockwise, closing direction, at point  75  ( FIG. 5 ), forcing element  50  encounters gradually upwardly sloping wall  74  of guidance recess  70 , then the steeper, downward slope of wall  72 , then rim  43  at section  56  and finally resistance recess wall  44  and steep wall  46 . 
         [0035]    In operation, during manufacture of the package, closure  22  is snap fit onto neck  32  (e.g.,  FIG. 2 ) of bottle  20  by closure  22  being pressed axially downwardly (or bottle  20  being pressed axially upwardly, or both), Since the bottle body and the closure are made of a flexible material and/or because the presence of one or more recesses in the pipe permits the cylindrical snap-on pipe  30  to expand resiliently radially, the internal thread  34  on the cylindrical snap-on pipe passes over the external thread  60  on the container neck and the closure snaps onto the neck. Thus, the closure is securely attached to the container and a substantial amount of effort would be needed for the consumer or other external force to separate them using a strictly vertical or upward axial motion. Alternatively, closure  22  may initially be applied onto container  20  by being rotated on, to engage the threads. 
         [0036]    In normal use, the product is dispensed with cover  26  removed from opening  36 . Cover  26  is then closed so that plug  40  seals the opening when the product is not in use. 
         [0037]    When the bottle is substantially empty of the shampoo, body wash, lotion or other product originally contained within, the consumer removes closure  22  from the package to facilitate refilling and reusing it. To initiate removal of the closure, the consumer rotates it, typically in the counterclockwise direction, starting from the position shown in  FIG. 6  wherein forcing element  50  is at least partly accommodated within recess  42 . Forcing element  50  forces closure  22  upwardly upon closure rotation as described above. Cylindrical snap-on pipe thread  34  maintains its position below container neck thread  60  as the closure is rotated at least until the forcing element reaches a position beneath the second guidance recess wall  72 , preferably until the forcing element reaches a position beyond the position beneath the second guidance recess wall. That is, the threads maintain their relative axial positions until the forcing element reaches such positions. 
         [0038]    Forcing element  50  next encounters section  56  of bottom rim  43  of the cylindrical snap-on pipe and then upwardly extending wall  72  of guidance recess  70 . The latter permits the cylindrical snap-on pipe axially to lower itself toward the container neck. Cylindrical snap-on pipe thread  34  remains below thread  60  whereupon the consumer can continue to use a normal rotation to unscrew the closure from the container neck.  FIG. 5  shows forcing element  50  within recess  70 . This unscrewing rotation may optionally be further facilitated by forcing element top  58  contacting downwardly extending wall  74  of guidance recess  70 . Optional contact by the top  58  with downwardly extending wall  74  may raise the closure cylindrical snap-on pipe to support the normal unscrewing action of the closure, whereby the closure is easily removed. The pitch of the threads is similar to the gradient of wall  74 . 
         [0039]    At some point in the opening rotation, preferably after the forcing element is beyond a location beneath the second guidance recess wall, the cylindrical snap-on pipe thread may optionally pass axially over the bottle thread whereby removal of the closure is facilitated. If this occurs, typically it will happen further into rotation in the opening direction than the position shown for forcing element  50  in  FIG. 5 , e.g. forcing element  50  will be closer to, preferably beyond, point  75 . Removal is also facilitated by interruptions in the external neck thread and/or the internal snap-on pipe thread and the flexible material of which the closure is made. Alternatively, as mentioned above the closure may be structured so that once the forcing element is disengaged from the resistance recess, with sufficient axial force the internal thread on the snap on pipe may pass over the external thread of the container neck to facilitate removal of the closure. 
         [0040]    With the closure removed, the consumer then refills the bottle with the shampoo or other product. She then applies the closure back onto the bottle either by snapping the closure downwardly over the bottle neck in an axial direction similar to that used in manufacture, or she screws the closure back on to the bottle neck. If she chooses the latter, the clockwise-moving rim  43  of pipe  30  optionally contacts top  58  of forcing element  50 . When it reaches point  75  ( FIG. 5 ), it encounters gradually ascending wall  74  which permits lowering of the pipe relative to the bottle neck consistent with the normal screwing downwardly of a closure. At this point, the threads have engaged. 
         [0041]    The forward and/or top wall of the forcing element encounters wall  72  of guidance recess  70  which accommodates raising of pipe  30  relative to bottle neck  32  and the top  58  of forcing element  50  optionally contacts section  56  of rim  43 . Upon further rotation, forcing element reaches resistance recess wall  44  and pipe  30  moves downwardly as forcing element  50  is accommodated within recess  42 . As the consumer rotates the closure closed, internal thread  34  of pipe  30  maintains its position below external thread  60  on bottle neck  32 . When forcing element wall  52  encounters steep wall  46  of resistance recess  42  the closure cannot be rotated any further. 
         [0042]    The closure can be placed on the container neck securely and economically by strictly vertical/axial placement on the bottle during manufacture, whereas by providing the consumer with the ability readily to rotate the closure for removal and to re-apply it to the bottle, refilling of the container is promoted. Closure  22  may be also be applied onto the container during manufacture by being rotated to engage the threads. 
         [0043]    References to upward or downward motion herein assume that container  20  is resting on its base (not shown) at its end opposite the closure. 
         [0044]    The closure may be made from polypropylene or polyethylene or similar polymeric materials, and the bottle can be molded from high-density polyethylene or polypropylene or PET. The closure is designed to be durable, resisting normal wear and tear by opening and closing the closure and even by dropping. 
         [0045]    Personal care products include products for application to the skin, the scalp or the mouth, such as shampoo, body wash, skin lotions, etc. 
         [0046]    It should be understood, of course, that the specific forms of the invention herein illustrated and described are intended to be representative only as certain changes may be made therein without departing from the dear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.