Abstract:
A fluid delivery device includes a compressible sleeve configured to hold a fluid-holding container such as an ampoule or capsule. The sleeve is compressible so as to be able to shatter the container under user-applied force to release the contents of the container for application to a desired location. The sleeve is constructed from at least two independent and separate walls. The independence of the walls improves the resistance of the sleeve to accidental puncturing by the frangible container while not significantly impacting the force required to shatter the container.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/423,738 filed on Dec. 16, 2010 and entitled Ampoule Protector and Method of Construction Thereof, the entirety of which is hereby incorporated by explicit reference thereto. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to fluid delivery devices, and more particularly, to fluid delivery devices including a holder such as sleeve for at least partially enclosing a fluid holding container such as an ampoule or capsule, wherein the fluid holding container is selectively breakable by user-applied pressure to the sleeve. 
         [0003]    It is generally known to provide a liquid delivery device including a sleeve that is configured to receive a crushable container such as an ampoule or capsule. The container typically includes a liquid that is to be applied to a desired location through, for example, an optional applicator. Typically, such sleeves are constructed of a single tube or a single tube composed of multiple layers formed together via a standard coextrusion process. In a coextruded construction, layers of the tube of the sleeve are typically coupled to one another by chemical adhesion or by a tie layer or the like. In some cases a rubber urethane tie layer is used as a functional layer between layers. The container is securable within a cavity defined by the sleeve and is typically constructed from glass or a similarly breakable material. The user applies a force to the sleeve sufficient to shatter or otherwise crush the container contained within the sleeve so that the fluid held within the container is released into the sleeve and may then be selectively dispensed via the applicator or similar element. When used in the coextruded type sleeve, the rubber urethane layer is thought to blunt the penetration of the container material into the outer tube of the coextruded holder to prevent the material from contacting the user. 
         [0004]    While assemblies of this kind are well known in the art, such assemblies suffer from a number of known disadvantages. For instance, such assemblies can result in an undesirable number of accidental punctures typically through repeated or overly aggressive pressing on the sleeve. 
         [0005]    Other known types of fluid delivery devices have sought to remedy the deficiencies of known fluid delivery devices by providing sleeves having thicker walls or considerably thicker coextruded layers. Others have provided independent paperboard sleeves for the user that slides over the plastic sleeve to provide additional puncture protection. These have the disadvantage of requiring a secondary manufacturing step of producing a paper sleeve as well as the added assembly of it to the finished unit. However, these types of fluid delivery devices require an undesirable amount of additional crushing force to be applied by the user to the sleeve to break the enclosed container for dispensing the fluid. Thus, it can be difficult for a user of such devices to break the container for selective dispensing of the fluid contained therein. In addition, these types of fluid delivery devices can still result in an undesirable amount of accidental punctures. 
         [0006]    Accordingly, a liquid delivery assembly that alleviates or eliminates one or more of the foregoing disadvantages is desired. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is generally directed to a fluid delivery device. The fluid delivery device includes a sleeve defining a cavity for receiving a frangible fluid container such as an ampoule or capsule. The fluid delivery device may include a delivery element such as an applicator for applying the fluid, which is coupled to the sleeve for selective application of the fluid. 
         [0008]    The sleeve includes at least two separate and independent tubes or walls of material. The material of the tubes or walls may be a plastic or other material having similar characteristics. The inner tube or wall of the sleeve may be formed by way of a standard extrusion process and then cooled. The outer tube or wall is applied over the inner tube or wall, but is not physically or chemically bonded with the inner tube or wall. Instead, the outer tube or wall intimately surrounds the inner tube or wall, which provides a sleeve having improved puncture resistance while still being relatively easily compressible so as to shatter or crush the container held within the sleeve. 
         [0009]    Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention. 
           [0011]    In the drawings: 
           [0012]      FIG. 1  is a longitudinal cross-sectional view of the fluid delivery device of an exemplary, first embodiment according to the present invention; 
           [0013]      FIG. 2  is a transverse cross-sectional view of the fluid delivery device of FIG. it; 
           [0014]      FIG. 3  is an enlarged view of a portion of the fluid delivery device of  FIG. 1 ; 
           [0015]      FIG. 4  is an enlarged view of a portion of the fluid delivery device as shown in  FIG. 2 ; 
           [0016]      FIG. 5  is a transverse cross-sectional view of a fluid delivery device according to a second embodiment of the present invention; and 
           [0017]      FIG. 6  is a partial longitudinal cross-sectional view of the fluid delivery device of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0018]    Referring now to the drawings and initially  FIG. 1 , a fluid delivery device  10  according to the invention includes a sleeve  12 , a container  14  such as an ampoule or capsule (hereinafter “ampoule  14 ”) that contains a fluid and that is at least partially secured within the sleeve  12 , and an applicator  16  receivable within an end of the sleeve  12  and which may extend outwardly therefrom for selective application of the fluid to a desired location. The sleeve  12  may be generally hollow and include a cavity  18  for receiving the ampoule  14 . As shown in  FIG. 1 , the ampoule  14  may be held such that its outer surfaces are spaced inwardly from the facing inner surface defined by the sleeve  12 ; however, it is to be understood that the ampoule  14  may be held within the sleeve  12  in close contact with the inner surface defined by the sleeve  12 . The ampoule  14  may likewise be generally hollow and include a cavity  20  for holding the fluid. The sleeve  12  and the ampoule  14  may be generally tubular in shape having a generally circular cross-section or may have any other such shape as desired. 
         [0019]    As will be discussed in additional detail, the sleeve  12  of the present invention is constructed from at least two independent and separate tubes or walls of material, shown at  30  and  32 . For the sake of convenience, the tubes or walls  30 ,  32  will hereafter be referred to as walls  30 ,  32 . The walls  32  may be formed of a material such as a plastic that is pliable or bendable while maintaining a desired amount of stiffness to enable the user to selectively shatter the ampoule  12  but to also provide the necessary structural integrity necessary to prevent accidental breaking and to prevent penetration by the shattered ampoule  14 . By maintaining the at least two walls  30 ,  32  independent and separate from one another, the crushing force required to break the ampoule  14  is minimized while the resistance to penetration of the sleeve  12  is also improved as will be discussed in detail herein. The at least two walls  30 ,  32  may be constructed from the same or different materials. 
         [0020]    The sleeve  12  may have a first end  22  and a second end  24  opposite the first end  22 . As illustrated, the first end  22  includes an opening in which the applicator  16  may be received, and the second end  24  is closed, sealed, or otherwise configured to prevent the loss of fluid from the fluid delivery device  10  other than through the applicator  16  when the ampoule  16  is broken. The first end  22  may have a solvent or the like applied thereto for softening the area of the sleeve  12  around the opening to accommodate insertion of the applicator  16 . The softening of the material enables the applicator  16  to be inserted under pressure and thereafter become “knit” or otherwise coupled with the sleeve  12  so as to keep it in place after evaporation of the applied solvent and the subsequent hardening of the area covered thereby. Alternatively, the applicator  16  may be integrally formed with the sleeve  12 . Understandably, the sleeve  12  may include alternative constructions wherein both the first end  22  and the second end  24  are open or closed or in which the first end  22  is closed and the second end  24  is open. 
         [0021]    The ampoule  14  may be made from glass or a similarly crushable material such that when the user applies a force to the sleeve  12 , the ampoule  14  is broken and the fluid contained in the ampoule cavity  20  is released into the cavity  18  of the sleeve  12 . The applicator  16  may be a pledget, nozzle, or the like. The fluid may then be directed toward the applicator  16  under gravity or by squeezing sleeve  20 , such that it becomes saturated or otherwise inundated with the fluid for selective delivery thereof. As is generally understood, the applicator  16  may be configured so as to prevent the introduction of any of the shattered pieces of the ampoule  14  into the applicator  16  so as to prevent the accidental dispensing thereof. 
         [0022]    The ampoule  14  may include a pair of opposing ampoule ends  26  and  28 , which may be sealed by welding or a similar method. The sealed ampoule  14  protects the integrity of the fluid contained therein by preventing fluid loss and the ingress of gases, water vapor, or other fluids that may be deleterious to the shelf life of the fluid. Oftentimes, the fluid contained in the ampoule  14  is for use in medical applications such as, for example, the application of topical sterilants, antiseptics, ointments, skin adhesives and the like although, understandably, the fluid may be any fluid capable of use with the fluid delivery device  10  of the present invention. 
         [0023]    With additional reference now to  FIGS. 2-4 , a first, exemplary, embodiment of the fluid delivery device  10  is illustrated in which the sleeve  12  includes the first or outer wall  30  and the second or inner wall  32 . In the present embodiment, the outer wall  30  and the inner wall  32  each have a single-layer construction. The outer wall  30  and inner wall  32  may be constructed from a twin-tube sleeve material formed through a tandem or sequential process. During the process, the inner wall  32  is formed with a conventional tubing extrusion process and cooled. The inner wall  32  may then be advanced to a second extrusion location where it is surrounded by the outer wall  30  around its entire circumference. Understandably, in at least one construction of the present invention, the sleeve  12  may be configured such that the outer wall  30  is provided around a majority or only a portion of the circumference of the inner wall  32 . For instance, the outer wall  30  may be applied about a portion of the inner wall  32  where the user is to compress the sleeve  12  for breaking the ampoule  14 . The outer wall  30  also may surround the inner wall  32  a full 360 degrees but have varying thickness depending on the position around the inner wall  32 . 
         [0024]    The outer wall  30  and inner wall  32  may be constructed from the same or different material. The resulting sleeve  12  is constructed of two completely separate and independent walls that are closely formed with one another but which are not physically or chemically adhered to one another. With reference now to  FIGS. 2-4 , there may be a small peripheral space  34  between the outer wall  30  and the inner wall  32 . The space  34  is exemplary only and is provided to illustrate the separate nature of the outer wall  30  and the inner wall  32 . The spacing between the outer wall  30  and the inner wall  32  may be practically imperceptible, or the outer wall  30  and inner wall  32  may be physically in contact with one another but without being otherwise physically or chemically secured together. 
         [0025]    By forming the sleeve  12  in this manner, the puncture resistance of the sleeve  12  is greatly improved as compared to layers that are physically, chemically or otherwise adhered to one another. In particular, each of the walls  30 ,  32  requires initiation of a separate tear propagation in order for the glass or similar material of the ampoule  14  to penetrate each of the respective walls  30 ,  32 . By separating the walls, the direction of the ampoule  14  breaking is diffused. Further, the amount of crushing force necessary to shatter the ampoule  14  is reduced compared to equivalent materials in traditional constructions. This is because the force to bend or buckle the sleeve is determined by the moment of inertia of the wall thickness, which is a function of the position of each mass element from the center of the respective tube. Thus, the required crush force is reduced as the resultant moments are a summation of the moments of the two thinner masses. In this manner, the calculated crush strength or stiffness of the structure is lower while improving the puncture resistance of the fluid delivery device  10  due to the need to propagate a tear initiation for each wall. This enables the overall material thickness of the sleeve to be increased if desired for additional improvements in puncture resistance with marginal increases in the crush force required to break the inner ampoule. 
         [0026]    The outer wall  30  and the inner wall  32  may be constructed from any number of materials including styrene butadiene copolymers, cellulose acetate butyrate (CAB), cellulose acetate proprionate (CAP), polycarbonate, copolyester, polyethylene tetrephtalate glycol (PETG), acrylonitrile-butadiene-styrene (ABS), polycarbonate (PC), cyclic olefin copolymers, polyamides, and the like. The walls  30 ,  32  of the sleeve  12  may be constructed from any number of alternative materials such as plastics and the like that are capable of deforming to allow the shattering of the enclosed ampoule  14  but which are also capable of preventing the penetration of the broken ampoule  14  through the walls  30 ,  32 . Any number of alternative materials may be used for constructing the sleeve  12  so long as the material is compatible with the fluid to be dispensed, capable of relatively easily deforming under user-applied pressure, does not have a propensity to crack when flexed, and has a relatively high resistance to puncture. 
         [0027]    The walls  30 ,  32  may be clear so that the user may visually examine the contents of the ampoule  14 . Alternatively, one or more of the walls  30 ,  32  may be opaque. In the case of an opaque construction, at least one of the walls  30 ,  32  may include a filler or foam that is added during the extrusion or other process. Further, a coating may be applied and dried on the surface of the inner wall  32  that may become wetted and visible, similar to a dye, if the inner wall  32  becomes compromised. In this way, a user may be made aware of a potential contamination or degradation of the contents of the ampoule  14 . 
         [0028]    Still referring to  FIGS. 2-4 , as noted previously, the walls  30 ,  32  may be constructed from the same, similar, or different materials. Moreover, the walls  30 ,  32  may be constructed from the same material but have differing plasticizer concentrations. For example, one of the walls  30 ,  32  may include a relatively low amount of plasticizer, e.g. on the order of 5% plasticizer, while the other includes a higher amount of plasticizer, e.g. on the order of 13% plasticizer. The differential in plasticizer concentration serves to further optimize the crush force required and puncture resistance properties of the sleeve  12 . As is generally understood in the art, the wall having the lower amount of plasticizer will be stiffer as compared to the wall having a higher amount. Thus, the wall with the lower amount of plasticizer requires greater crushing force to deform but has improved puncture resistance compared to the wall with the higher amount. Understandably, various plasticizer concentrations and combinations may be used and are contemplated to be within the scope of the present invention. For instance, the walls  30 ,  32  may have identical, more similar, or more disparate concentrations of plasticizer as may be desired. 
         [0029]    Rather than providing one of the walls  30 ,  32  with differing amounts of plasticizer, an alternative method of altering the relative properties of the walls  30 ,  32  may be employed. For instance, in addition to or in the alternative, one of the walls  30 ,  32  may have an increased thickness relative to the other wall  30 ,  32 . 
         [0030]    In one construction of the sleeve  12 , the walls  30 ,  32  may be incorporated into a single extrusion die head. The melted plastic or other material forming the wall  30  may be configured to exit the die head first, and once the material is cooled, the die head may be configured to deliver the material of the second wall  32 . The die head may include different die tips configured to keep the dies separate from one another to thereby reduce the cost of producing the sleeve as compared to using two or more die heads. 
         [0031]    In another construction, materials that are otherwise adhesively incompatible may be inserted between the walls  30 ,  32  to create three separate independent layers. For instance, two CAB layers may be extruded with a layer of polypropylene (PP) between them from a single die head using three separate extruders. The lack of chemical adhesion between the CAB and PP layers may cause the walls  30 ,  32  to delaminate during flexing. In yet another construction, the walls  30 ,  32  may be configured to separate from one another during cooling as a result of having differing thermal expansion coefficients or due to crystallization occurring in the PP layer. 
         [0032]    Now referring to  FIGS. 5 and 6 , an alternative construction of a fluid delivery device of the present invention, shown at  110 , is illustrated. The delivery device  110  of this embodiment may have a double wall construction, similar to that of delivery device  10 , wherein one of the walls  130 ,  132  may include a number of coextruded sub-layers as will be discussed herein. As illustrated, the inner wall  132  of the sleeve  112  is constructed of an outermost inner sub-layer  132   a,  an intermediate inner sub-layer  132   b,  and an innermost inner sub-layer  132   c.  Understandably, the sleeve  112  may be constructed in an alternative manner such that the outer wall  130  includes the co-extruded sub-layers while the inner wall  132  has a single layer construction. Similarly, both the inner wall  132  and the outer wall  130  may be constructed from a number of sub-layers. The inner wall  132  is configured such that the sub-layers  132   a - 132   c  are physically coupled to one another in a traditional manner while the outer wall  130  and the inner wall  132  remain separate from one another. Understandably, the walls  130 ,  32  may be arranged in accordance with the walls  30 ,  32  and constructed in a similar manner as previously discussed. 
         [0033]    In a first exemplary construction of the sleeve  112 , the outer wall  130  may be constructed from a material such as CAB. The outer wall  130  may entirely surround the inner wall  132  in an independent and entirely separate manner as previously discussed. The outermost inner sub-layer  132   a  may be constructed from a CAB material, the intermediate inner sub- layer  132   b  may be constructed from a thermoplastic polyurethane (TPU) material, and the innermost inner sub-layer  132   c  may be constructed from a CAB material. Of course, any number of alternative materials may be used in constructing the sleeve  112  in accordance with the present embodiment. 
         [0034]    Moreover, in another exemplary construction of the sleeve  112 , the thicknesses of the walls  130 ,  132  may be configured to provide a desirable combination of stiffness to prevent puncturing and to maintain pliability to enable the user to easily crush the enclosed ampoule (not shown). For instance, in one construction, the outer wall  130  may be a 6 mil CAB layer, and the inner wall  132  may be 14 mil in total and include an outermost inner sub-layer  132   a  that is 6 mil CAB, an intermediate inner sub-layer  132   b  that is 2 mil TPU, and an innermost inner sub-layer  132   c  that is 6 mil CAB. Thus, the resulting sleeve  112  will have a thickness of about 20 mil. Such a construction will minimally increase the crushing force necessary to break the ampoule while greatly improving the resistance of the sleeve  12  to puncturing by the shards of the broken ampoule. Understandably, any of the walls  130 ,  132  may have differing thicknesses. For instance the outer wall  130  may be 8 or 10 mil thick or the like to provide a sleeve of about 22-24 mil thick. The resulting sleeve  112  will have an improved puncture resistance while still being relatively easy to compress so as to shatter the enclosed ampoule. 
         [0035]    In practice, the inner wall such as  32  or  132  (referred to as  32  for convenience) is formed first by conventional means such as extrusion. Once the inner wall  32  is formed, it is cooled prior to having the outer wall  30  or  130  (referred to as  30  for convenience) applied thereto. In particular, as discussed previously, the outer wall  30  may be disposed about the inner wall  32  so as to surround it. However, the outer wall  30  is not bonded, physically or chemically, to the inner wall  32 . In at least one embodiment of the present invention, the inner wall  32  may be cooled via a cooling tank or similar applicator so as to ensure that the inner wall  32  is sufficiently cooled by the time the outer wall  30  is applied. As the temperature of the die head applying the outer wall  30  may be sufficient to melt or elongate the inner wall  32 , it is desired that the inner wall  32  be sufficiently cooled beforehand to reduce the likelihood of melting. For example, the inner wall  32  may be super-cooled as is generally understood to lower the temperature of the inner wall  32  to reduce the likelihood of melting. In such cases, it may be desirable to include a drying step to the process so as to remove any water or condensation that may have developed during the cooling of the inner tube  32 . Moreover, it may be desired to maintain the inner wall  32  at a sufficient distance from the die head applying the outer wall  30  such that the die head does not physically contact the inner wall  32 . In another construction of the sleeve  12 , the die head applying the outer wall  30  may be fitted with a porcelain lead in insulator guide, or similar element, to minimize the contact between the die head and the inner wall  32 . Also, it may be desirable to make the inner wall  32  thicker than the outer wall  30  so as to minimize any loss in thickness created by the application of the heat to the inner wall  32 . For the reasons previously articulated, it is desirable to minimize the residence time that the inner wall  32  is in the hot coating zone of the die head applying the outer wall  30  thereto. 
         [0036]    The present invention has been described in terms of representative embodiments, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.