The present invention relates generally to bottle closures.
Bottle closures for consumable liquids, for example, olive oil, syrup, spirits and wine, have historically been metal and/or cork material. Cork is made from bark of certain trees, for example, the Cork Oak. Cork has qualities particularly suited to storing liquids in bottles because it features impermeability and a certain level of compressibility that allows for both a tight closure and removability. In contrast to bark, wood fibers do not have sufficient compressibility.
Due to extensive use, however, cork supplies are limited, thereby driving up price. Moreover, cork closures carry with them the risk of a taint that can be passed into the liquid. For example, it has been estimated that as many as seven percent of wine bottles have some level of “corking”, or taint imparted by the cork.
By far, the most popular closure for mass-produced bottled liquids is the metal “screw top cap”. Metal screw tops are formed of a metal skirt and plastic sealing layer. Screw tops extend over the outside of the bottle, as opposed to corks that are inserted into the bottle neck. While screw top caps are not susceptible to taint, screw top caps lack aesthetic appeal, which is particularly disadvantageous for higher-valued products such as fine spirits, fine wine, and higher end olive oil and maple syrup.
In other cases, it has been found that certain polymers can be used for bottle closures that behave in a manner more similar to cork. Polymer closures can have similar compressibility. However, polymer closures similarly suffer from a lack of aesthetics associated with fine spirits, wine and other products. Furthermore, polymer closures are given to “creep”, which deforms the closure over time and can lead to failure.
Some attempts have been made to combine certain materials with the polymer closure to take advantage of the mechanical properties of the polymer while improving the aesthetics. In one example, a closure includes a wooden head or cork head portion glued to a thermoplastic polymer portion. The thermoplastic polymer portion inserts into the bottle, while the wooden head remains outside the bottle and provides a gripping portion for extraction. The drawback of this design is that the glue joints often fail, causing separation of the polymer sealing material from the wood.
What is needed is a bottle closure that has sealing qualities comparable to cork, while having a suitable aesthetic human interface.
The present invention addresses the above stated need, as well as others, by providing a bottle closure having a wooden core (and head), with a polymer molded onto the wooden core. The wooden core provides structural integrity and the wooden head provides a convenient and aesthetic removal interface.
In a first embodiment, the closure for a bottle includes a wooden head portion and a stopper portion. The wooden head portion has a recess formed therein. The stopper portion has a polymer inner member and a polymer outer member. The polymer inner member includes a first part embedded in the recess in the wooden head and a second part extending away from the wooden head and substantially covered by the polymer outer member.
In another embodiment, a closure for a bottle includes a wooden element, a first polymer layer, and a second polymer layer. The wooden element has a recess formed therein. The first polymer layer is molded into the recess in the wooden element. The first polymer layer also has an outer surface with at least one circumferential discontinuity. The second polymer layer is disposed over the first polymer layer. The second polymer layer is configured to be received by a bottle in the axial direction.
In yet another embodiment, a closure for a bottle includes a wooden element having an upper surface, a lower surface, and a recess formed in the lower surface. The closure also includes a first polymer layer including a footing and an extension. The footing is molded into the recess in the wooden element, and the extension extends away from the footing and the wooden element. The footing is integrally formed with the extension as a unitary component. The closure further includes a second polymer layer molded onto the first polymer layer. The second polymer layer is configured to be received by a bottle in the axial direction.
The above-described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings.
With reference to
As discussed above, the head portion 104 and the wooden inner part 106 are integrally formed from a single piece of wood, as opposed to bark material used for corks. Suitable wood materials include, but are not limited to beech, birch, maple, oak, bamboo. The wooden inner part 106 is in the form of a shaft having a first end 120 at the intersection of the head portion 104, and a distal or second end 122.
The wooden inner part or shaft 106 defines a generally cylindrical structure having at least one discontinuity. The discontinuity provides an area where the polymer outer part 108 can contract onto and “grip” the wooden inner part 106 during the molding process. In this embodiment, the discontinuities include two annular grooves 110, 112. The annular groove 110 includes a radially extending upper surface 114, a radially extending lower surface 116 and an axial inner surface 118. The annular groove 112 may suitably have the same structure. The annular grooves 110, 112 are spaced apart on the wooden inner part 106 by an axial distance that is roughly equivalent to the axial width of the axial inner surface 118. Similarly, the annular grooves 110, 112 are spaced apart from the two axial ends 120, 122 of the wooden inner part/shaft 106.
One feature of the annular grooves 110, 112 is the provision of an undercut, preferably in a radial plane. For example, in the annular groove 110, the upper surface 114 and the lower surface 116 form undercuts. As will be discussed below in further detail, when the polymer outer part 108 is molded onto the wooden inner part 106, the polymer engages the undercuts and contracts, thereby strengthening the retention force of the polymer outer part 108 on the wooden shaft 106. Accordingly, it will be appreciated that suitable undercuts may take other forms, such as detents, bores, and the like. One advantage of a continuous annular groove such as the grooves 110, 112 is that it allows the undercuts to be formed in a rotating wood working fixture, such as a lathe.
It is also preferable that the grain 111 of the wood part 109 be oriented in the axial direction, or in other words, substantially parallel to the angle of insertion into the bottle. Such orientation advantageously provides maximum bending strength on the core, and optimum fiber orientation for product insertion and extraction forces.
Accordingly, to construct the wood part 109, a blank wood piece is loaded onto a lathe or other rotating machine such that the grain of the wood blank is parallel to the axis of rotation. Suitable machining methods are used on the rotating wood blank to form the wood part 109 as shown in
In this embodiment, the wooden shaft 106 also includes an annular mold mating structure 124 at the first end 120, adjacent to an engaging the underside of the head portion 104. The annular mold mating structure 124 in this embodiment defines an inclined annular surface similar to a fillet structure. The annular mold mating structure 124 is configured to provide an interface for the molding fixture, not shown. The molding fixture can clamp down and slightly deform the mating structure 124 to form a tight contact ring between the mold and the shaft, thereby inhibiting or preventing undesirable leaks or flashing of the polymer material beyond its intended position.
As discussed above, the polymer outer part 108 defines a substantially cylindrical outer wall 126 that engages the inner wall of a bottle. In a first embodiment discussed below in connection with
Referring to
It can be seen that the polymer outer layer 108 fills the annular grooves 110, 112, and forms a layer over the second end 122 of the wooden shaft 106. In the cross-section shown in
When the polymer cures, it contracts (shrinks), forming axial clamping forces on the undercuts (e.g. radially extending surfaces 114, 116) and on the second end 122 of the wooden shaft 106. The polymer preferably shrinks at least one or two percent. Such clamping forces help secure the structure and prevent failure or separation. In addition, the random “pitting” or hollow spots 113 on the shaft 106 formed during the manufacturing process provides places for the polymer to lock during post-molding shrinkage to enhance the mechanical bond. This method of mechanical shrinkage bonding provides superior torque resistance between the wood shaft 106 and the polymer shaft 108. Such torque resistance is particularly advantageous because this type of closure is often rotated, relative to the bottle, upon insertion and extraction. Also, the porosity and pits in the wood (imperfections) provide excellent asymmetric, random grip points for the shrink bond of the molded polymer.
Accordingly, the material of the polymer outer portion 108 should be chosen such that it is soft or elastic enough to allow for bottle insertion and extraction, while providing a tight liquid seal, and have sufficient hardness to secure itself about the wooden shaft 106. To this end, the polymer may suitably be one or more of propylene, thermoplastic elastomer, a blowing agent (endothermic), or SEBS. One suitable blend is the TPE and blowing agent described in U.S. Pat. No. 5,710,184.
The first polymer layer 130 has a greater hardness, and may have greater shrinkage, than the second polymer layer 132, thereby allowing for strong coupling to the wood shaft 106. The second polymer layer 132 may be softer, and even softer than the polymer material of the embodiment of
In one preferred embodiment the first polymer layer 130 may include polypropylene and the second polymer layer 132 may include thermoplastic elastomer (TPE). However, either or both of these materials may be altered.
Referring now to
The stopper portion 202 includes a wooden inner part 206 and a polymer outer part 208, the polymer outer part including a first polymer layer 230 and a second polymer layer 232. Further details regarding the polymer outer part 208 are discussed further below in connection with
The wooden inner part or shaft 206 defines a generally cylindrical structure having at least one discontinuity. The discontinuity provides an area where the polymer outer part 208 can contract onto and “grip” the wooden inner part 206 during the molding process. In this embodiment, the discontinuities include two annular grooves 210, 212. Thus, the shaft 206 is similar to the shaft 106 shown in
Moreover, it will be appreciated that the reduced length shaft 206 may readily be employed in the embodiments of the closure 100 discussed above in connection with
As discussed above in connection with
In contrast to the embodiment of
The discontinuities formed by the ribs 242 create torsion that assists in retaining the strong bond between the first polymer layer 230 and the second polymer layer 232. It will be appreciated that the ribs 242 may be replaced with some other structure on the shaft 240 that form such discontinuities. In this embodiment, the inner shaft 240 is roughly bullet shaped, have a substantially cylindrical body 250 extending from the head portion 204 and terminating in a rounded conical point 252. The ribs 242 extend along the entire length of the inner shaft 240, including the length of the rounded conical point 252, as shown in
Referring now to
Unlike the previously described embodiments, the stopper portion 302 of the embodiment of
The polymer inner layer 330 includes a footing 340 and an extension in the form of a knob 350. The footing 340 is substantially cylindrical in shape and includes an enlarged rim 342, a cylindrical wall 344, and a plurality of axial grooves 346 extending along the cylindrical wall 344. Both the rim 342 and the cylindrical wall 344 have a circular cross-sectional shape. As best shown in
The knob 350 includes a solid core member 352 with a substantially cylindrical shaft 354 that extends away from the footing 340 starting at a curved lip 358 that abuts a lower surface 364 of the wooden head portion 304. As best shown in
The footing 340 and the knob 350 of the polymer inner layer 330 are integrally formed from a single material such that the polymer inner layer 330 is configured as a unitary component. Accordingly, the footing 340 and the knob 350 are not separable without destruction of the polymer inner layer 330. Similar to the inner polymer layers 130, 230 of previous embodiments, the inner polymer layer 330 of the stopper portion 302 in the embodiment of
The second polymer layer 332 provides a generally solid cylindrical structure that covers the inner polymer layer 330, including the core 352, ribs 356 and lip 358 of the inner polymer layer 330. The second polymer layer 332 provides a generally smooth and continuous outer cylindrical surface 326 for the stopper portion 302. The second polymer layer 332 is molded onto the first polymer layer 330 using a process and material that creates a cohesive bond between the second polymer layer 332 and the first polymer layer 330. Similar to the outer polymer layers 132, 232 of previous embodiments, the outer polymer layer 332 of the stopper portion 302 in the embodiment of
With particular reference now to
The lower surface 364 of the wooden head portion 304 includes an outer circular surface 366, a central recess 370, and a mount 380. The outer circular surface 366 is configured to abut the rim of a bottle and is generally flat and smooth without significant surface irregularities. The central recess 370 includes a circular innermost portion 372, a circular intermediate portion 374, and a disk-shaped outermost portion 376. The circular innermost portion 372 and the circular intermediate portion 374 of the recess 370 define a two-stage annular groove having a T-shaped cross-section. The two-stage groove is comprised of two different radial widths, with a greater width defined by the circular innermost portion 372 (which provides the cross-member of the T-shaped cross-section) and a lesser width defined by the circular intermediate portion 374 (which provides the upright of the T-shaped cross-section).
The circular mount 380 is positioned at the center of the recess 370 and is comprised of wooden material. The circular mount 380 includes a base 382 and a platform 384, the platform 384 having a greater diameter than the base. Because the platform 384 has a greater diameter than the base 382, a shoulder is formed between the base 382 and the platform 384. The base 382 may further include a number of axial ribs that compliment and engage the axial grooves 346 in the footing 340 of the polymer inner member 330. The circular innermost portion 372 of the recess 370 is formed around the base 382, and the circular intermediate portion 374 of the recess 370 is formed around the platform. As noted above, the radial width of the two-stage groove defined by the recess 370 is greater at the innermost portion 372 than at the narrower intermediate portion 374. This two-stage groove results in undercuts in the wooden head at the shoulder in the mount 380 between the base 382 and the platform 384, and these undercuts are used to lock the polymer inner member 330 onto the wooden head portion 304, as noted below. Additionally, the disk-shaped outermost portion 376 of the central recess 370 is formed adjacent to the platform 384 and extends across the entire outer surface 386 of the platform 384, such that the radial width of the recess 370 is greatest at the outermost portion 376. Because of this, the outer surface 386 of the platform is provided in a different plane than the lower surface 364 of the wooden head portion 304, with the two relatively flat surfaces separated by the depth of the outermost portion 376 of the central recess 370.
As best shown in
The foregoing arrangement also provides for a method of making a bottle closure 300. The method includes forming a recess 370 in a wooden head portion 304. The recess may be formed from any of a plurality of suitable methods, including machining, carving or otherwise cutting the wood of the wooden head portion 304. The method also comprises molding a polymer inner member 330 on the wooden head portion 304. Molding the polymer inner member 330 includes filling the recess 370 with a relatively hard polymer material in order to provide a polymer inner member 330. The polymer inner member 330 includes a footing 340 that is embedded in the wooden head portion 304 and an extension 350 that extends outward from the wooden head portion 304. The method further comprises molding a polymer outer layer 332 on the polymer inner member 330. The polymer outer layer 332 is comprised of a relatively soft polymer material that substantially cover the polymer inner member 330 and abuts the wooden head portion 304. Together, the polymer inner member 330 and the polymer outer member 332 form the stopper portion of the bottle closure 300.
It will be appreciated that the above-described embodiments are merely illustrative, and that those of ordinary skill in the art may readily devise their own implementations and modifications that incorporate the principles of the present invention and fall within the spirit and scope thereof. By way of example, it will be appreciated that the dimensions of the closures 100, 200, 300 may be altered to suit the bottle neck design. In addition, the length of the stopper portions 102, 202, 302 and width of the head portion 104, 204, 304 may be altered without departing from the principles of the embodiments described herein.
In addition, it will be appreciated that the discontinuities used to strengthen the bond between the wood shafts 106, 206 and the polymer out layer(s), and as well as the discontinuities used to strengthen the bond between the polymer inner layer 330 and the polymer outer layer 332 may take different forms. Additionally, the bond between the polymer inner layer 330 and the recess 370 in the wooden head portion 304 may take different forms. While the embodiment described herein relies on annular grooves and hollow spots chipped out during machining, at least some embodiments may rely solely on discontinuities formed by chipped-out hollow spots formed during the machining of the shaft or the head portion 104, 204, 304. In addition, other forms of chipping or forming of overhangs the shaft may be employed. Nevertheless, the use of at least two annular grooves has been shown to provide particularly reliable connection between the wood shafts 106, 206 and the polymer outer parts 108, 208, as well as the embedding of the polymer inner layer 330 in a mount 380 in a recess 370 the wooden head portion 304.
The foregoing detailed description of exemplary embodiments of the bottle closure having a wood top have been presented herein by way of example only and not limitation. It will be recognized that there are advantages to certain individual features and functions described herein that may be obtained without incorporating other features and functions described herein. Moreover, it will be recognized that various alternatives, modifications, variations, or improvements of the above-disclosed exemplary embodiments and other features and functions, or alternatives thereof, may be desirably combined into many other different embodiments, systems or applications. Presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the appended claims. Therefore, the spirit and scope of any appended claims should not be limited to the description of the exemplary embodiments contained herein.
This application is a continuation-in-part of U.S. patent application Ser. No. 14/970,405, filed Dec. 15, 2015, which is a continuation-in-part of U.S. patent application Ser. No. 14/015,827, filed Aug. 30, 2013, the contents of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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Parent | 14970405 | Dec 2015 | US |
Child | 15420867 | US | |
Parent | 14015827 | Aug 2013 | US |
Child | 14970405 | US |