Abstract:
A disposable dispensing capsule for a plant injectable liquid composition includes a flexible cap hermetically sealed to a receptacle. The capsule is pressurized when the cap is forcibly flexed inwardly. In one embodiment flexure and thereby pressurization are maintained by an interference fit between a spindle in the receptacle and a socket depending downwardly from the cap central portion. In another embodiment flexure is maintained by engagement of hook-shaped posts in the receptacle with a lip in a collar depending downwardly from the cap central portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of application Ser. No. 29/159,143 filed Apr. 17, 2002, entitled “Dispensing Capsule for Pesticides and Nutrients,” now pending. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to devices for injecting plants, principally trees, with therapeutic liquid compositions such as pest control agents and nutrients. More particularly, it relates to devices providing for safe handling of toxic liquids in economical disposable containers within which a slight super-atmospheric pressure can be developed by the user which forces the liquid contents out of the container and into a feeder tube inserted into a tree trunk or other plant stem.  
           [0004]    2. Description of the Related Art  
           [0005]    The treatment of plants, especially trees, through injection of pest control agents and liquid nutrients has been known for some time. U.S. Pat. No. 3,286,401 to J. J. Mauget (“&#39;401”) discloses an apparatus and method for such treatment wherein a container including two mutually slidable cups with spaced interlocks is used in combination with a feeder tube which at one end penetrates a frangible diaphragm sealing a container aperture; the other end is driven into the plant stem. The telescopically compressible cups provide a container with a variable interior volume partially filled with a liquid composition; the remainder of the volume is occupied by a gaseous substance such as air. Sealing of the liquid contents is effected by means of interference fits between the concentric, smooth walls of the cups. This arrangement does not always provide a reliable seal. Small variations in the concentricities and dimensions of the cups and/or in atmospheric pressure, as well as imperfections due to interior surface scratches can permit discharge between the mutually slidable walls of at least a portion of the contents during shipment or storage. Such leakage is especially likely to occur if the liquid has a high affinity for forming a capillary film. Since liquid compositions such as insecticides and fungicides used to treat plants may be toxic or otherwise harmful to humans, it is important that the possibility of leakage under shipment, storage and operational conditions be eliminated.  
           [0006]    U.S. Pat. No. 4,365,440 (“&#39;440”) to D. D. Lenardson discloses a similar telescopically compressible container with improved sealing. The container includes a pair of cup-like body portions having interfitting and mutually slidable sidewalls which telescopically engage through open ends of the portions. The upper portion (or closure) has a base and a depending cylindrical sidewall. The lower portion (or receptacle) has a base and outer and inner concentric, spaced cylindrical sidewalls determining an annular socket for slidably receiving the closure sidewall. The distance between two parallel rings projecting from the outer surface of the closure sidewall determines the extent of axial travel of the compressed container. The inner surface of the receptacle outer wall has a groove for successively receiving the rings. A ratchet-like ring configuration impedes reversible disengagement of the closure from the receptacle while permitting forward, telescopically compressible relative movement of the receptacle and closure. Compression of the internal volume of the container pressurizes the fluid contents, forcing liquid into a connected feeder tube. Although the seal provided by the ring-and-groove combination minimizes leakage, it is not totally hermetic.  
           [0007]    U.S. Pat. No. 5,249,391 to J. A. Rodgers discloses a telescopically compressible binary container including an integrated liquid discharge tube. The container is intended to be non-disposable, in contrast to the &#39;401 and &#39;440 containers. The tube, which is slidably carried by a guide tube, resists being pulled from the guide tube when it is withdrawn from a tree upon completion of an injection operation. A resiliently deformable latch on one container section and a latch surface and cam means on the other container section engageable with the latch combine to provide locking in the compressed position. The container sections may be divided into separate volumes for storing dissimilar liquid and liquid or solid compositions. When a seal is ruptured by piercing means carried by the latch, the several compositions are mixed prior to entering the discharge tube.  
           [0008]    Other devices for injecting plants which do not utilize the technique of self-pressurizing a compressible binary container are known. For example, U.S. Pat. No. 6,032,411 to V. K. Foust and U.S. Pat. No. 5,239,773 to G. D. Doolittle, Jr. disclose a two-piece syringe, U.S. Pat. No. 4,989,366 to T. A. DeVlieger discloses a device including a plunger and funnel, and U.S. Pat. No. 4,144,673 to D. H. Quast et al. discloses a gravity-fed multi-injector system.  
         OBJECTS OF THE INVENTION  
         [0009]    It is a primary object of the present invention to provide a hermetically sealed, disposable capsule for injecting a plant with a liquid composition which will not leak during shipment, storage or during an injection operation.  
           [0010]    Another object of the invention is to provide a telescopically compressible capsule which will remain locked when in a pressurized state.  
           [0011]    Yet another object of the invention is to provide a capsule which is inexpensive to fabricate and suitable for mass production using thermoplastic injection molding.  
           [0012]    Other objects of the invention will become evident when the following description is considered with the accompanying drawing figures. In the figures and description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawings and description.  
         SUMMARY OF THE INVENTION  
         [0013]    These and other objects are achieved by the present invention which in one aspect provides a plant injection dispensing capsule including a receptacle containing a therapeutic liquid composition and having a floor and a wall, orthogonal to the floor, terminating in a rim. The capsule further includes a cap having a central portion, a flexible portion symmetric about the central portion, and a circumferential edge hermetically sealed to the rim. The capsule further includes means for maintaining inward flexure of the flexible portion, thereby keeping the capsule pressurized.  
           [0014]    In another aspect the invention provides a plant injection dispensing capsule including a receptacle containing a therapeutic liquid composition and having a planar floor and a cylindrical wall, orthogonal to the floor, terminating in a circular rim. The wall has an aperture proximate to the floor sealed by a dislodgeable membrane, and the floor has a channel proximate to the aperture. The capsule further includes a cap having a rigid central portion circumscribed by concentric annuluses bridged by stepped ridges orthogonal to the annuluses, and a circular edge hermetically sealed to the rim. The cap flexes inwardly when a downward force is applied to its central portion. The receptacle further includes an upwardly tapering spindle depending upwardly from the floor and having an outer surface. The cap further includes a polygonal-shaped socket, depending downwardly from its central portion, having a polygonal bore determined by a plurality of planar surfaces. The spindle is forcibly received within the bore when the cap is forcibly flexed inwardly, thereby pressurizing the capsule and creating an interference fit between the spindle outer surface and the socket bore surfaces which maintains the inward flexure.  
           [0015]    In still another aspect the invention provides a plant injection dispensing capsule including a receptacle containing a therapeutic liquid composition and having a planar floor and a cylindrical wall, orthogonal to the floor, terminating in a circular rim. The wall has an aperture proximate to the floor sealed by a dislodgeable membrane, and the floor has a channel proximate to the aperture. The capsule further includes a cap having a rigid central portion circumscribed by concentric annuluses bridged by stepped ridges orthogonal to the annuluses, and a circular edge hermetically sealed to the rim. The cap flexes inwardly when a downward force is applied to its central portion. The receptacle further includes three posts depending upwardly from the floor. Each post has a hook-shaped upper portion with a planar lower surface, and a lower portion orthogonal to the floor. The cap further includes a cylindrical collar, depending downwardly from its central portion, having a distally tapering end portion with a circumferential groove determining an annular lip having a generally planar upper surface. The lower surface of each post upper portion engages the lip upper surface when the cap is forcibly flexed inwardly, thereby maintaining the inward flexure to keep the capsule pressurized.  
           [0016]    A more complete understanding of the present invention and other objects, aspects and advantages thereof will be gained from a consideration of the following description of the preferred embodiments read in conjunction with the accompanying drawings provided herein. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a perspective view of a plant injection dispensing capsule including a cap and receptacle, according to first and second embodiments of the invention.  
         [0018]    [0018]FIG. 2 is a perspective view of the underside of the FIG. 1 capsule.  
         [0019]    [0019]FIG. 3 is a perspective view of the FIG. 1 receptacle according to the first embodiment including a floor, a cylindrical wall, a spindle depending upwardly from the floor, and a housing having a planar surface.  
         [0020]    [0020]FIG. 4A is a top perspective view of the FIG. 1 cap according to the first embodiment.  
         [0021]    [0021]FIG. 4B is an underside perspective view of the FIG. 1 cap according to the first embodiment.  
         [0022]    [0022]FIG. 5 is a sectional view of the FIG. 1 capsule according to the first embodiment, along cutting plane  5 - 5 , before the cap is flexed inwardly.  
         [0023]    [0023]FIG. 6 is a sectional view of the FIG. 1 capsule according to the first embodiment, along the FIG. 5 cutting plane, after the cap has been flexed inwardly, pressurizing the capsule, an aperture in the wall has been slidably postioned over one end of a feeder tube inserted into a tree trunk or plant stem, and a force has been applied to the FIG. 3 planar surface so that the tube end dislodges a membrane within the aperture.  
         [0024]    [0024]FIG. 6A is a detail view of region “ 6 A” in FIG. 6.  
         [0025]    [0025]FIG. 6B is a detail view of region “ 6 B” in FIG. 6.  
         [0026]    [0026]FIG. 7 is a perspective view of the FIG. 1 receptacle according to the second embodiment including a floor, a cylindrical wall, three posts depending upwardly from the floor, and a housing having a planar surface.  
         [0027]    [0027]FIG. 8 is an underside perspective view of the FIG. 1 cap according to the second embodiment.  
         [0028]    [0028]FIG. 9 is a sectional view of the FIG. 1 capsule according to the second embodiment, along cutting plane  9 - 9 , before the cap is flexed inwardly.  
         [0029]    [0029]FIG. 10 is a sectional view of the FIG. 1 capsule according to the second embodiment, along cutting plane  10 - 10 , before the cap is flexed inwardly.  
         [0030]    [0030]FIG. 11 is a sectional view of the FIG. 1 capsule according to the second embodiment, along cutting plane  11 - 11 , after the cap is flexed inwardly, pressurizing the capsule, an aperture in the wall has been slidably postioned over one end of a feeder tube inserted into a tree trunk or plant stem, and a force has been applied to the FIG. 7 planar surface so that the tube end dislodges a membrane within the aperture.  
         [0031]    [0031]FIG. 12 is a sectional view of the FIG. 1 capsule according to the second embodiment, along cutting plane  12 - 12 , after the cap is flexed inwardly, pressurizing the capsule. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    I. Introduction  
         [0033]    While the present invention is open to various modifications and alternative constructions, the preferred embodiments shown in the drawings will be described herein in detail. It is to be understood, however, there is no intention to limit the invention to the particular forms disclosed. On the contrary, it is intended that the invention cover all modifications, equivalences and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.  
         [0034]    Referring to FIGS. 1, 2 and  3 , a plant injection dispensing capsule  20  according to a first embodiment of the invention includes a cap  22  having a circumferential, generally circular edge  23  hermetically sealed to a circumferential, generally circular rim  25  of a receptacle  24 . As best shown in FIG. 3, receptacle  24  has an interior volume determined by a circumferential, generally cylindrical wall  26 , terminating upwardly in rim  25 , which is generally orthogonal to a generally planar floor  28  having an upper surface  28 S. Depending upwardly from floor  28  and proximate to its center of symmetry is an upwardly tapering spindle  30 , in the shape of a conical frustum, having an outer surface  30 S, a top  31  and a bore  32 . Receptacle  24  further includes a housing  34  attached to wall  26  which provides a generally planar force application surface  35 , a hollow base  36  for the capsule, and structural support for the wall. As shown in FIG. 2, ribs  38 A,  38 B,  38 C are attached between an interior surface  40  of housing  34 , and wall  26  and floor  28 . Wall  26  includes an aperture  42  proximate to floor  28  and external to housing  34  into which is inserted an inner end  44 A of a feeder tube  44  (not part of the invention) having an outer end  44 B terminating in an outlet  46 . Alternatively, the aperture may be internal to the housing. As is described below, and in an illustrative technique, feeder tube outer end  44 B is inserted into a predrilled hole in a tree trunk or plant stem and the aperture  42  of a pre-pressurized capsule is slidably positioned over the feeder tube inner end  44 A to secure the capsule to the feeder tube. Preferably, receptacle  24  is molded as a single unit from polypropylene or a similar thermoplastic. Most preferably, the receptacle is molded from a clarified polypropylene copolymer which includes propene, ethene and modifiers/additives, such as product P5M6K-048 available from Huntsman Polymers Corporation of Houston, Tex.  
         [0035]    Referring to FIGS. 4A and 4B, cap  22  includes a rigid central portion  50  circumscribed by a plurality of concentric annuluses  52 A,  52 B,  52 C bridged consecutively pairwise, respectively, by a plurality of stepped ridges  54 A,  54 B,  54 C generally orthogonal to the annuluses so that the cap initially is convexly arcuate. The ridges act as “living hinges” enabling cap  22  to flex inwardly when a downward force, as by a thumb, is applied to central portion  50 , depressing the portion. Depending downwardly from portion  50  is a socket  60  terminating in an end  60 E and having a hexagonal-shaped bore  62  determined by a plurality of generally planar surfaces  64 A,  64 B,  64 C,  64 D,  64 E,  64 F. Preferably, cap  22  is molded as a single unit from polypropylene or a similar thermoplastic. Most preferably, the cap is molded from a clarified polypropylene copolymer such as Huntsman product P5M6K-048.  
         [0036]    [0036]FIG. 5 depicts capsule  20  in its initial (unpressurized) state. Receptacle  24  contains a preselected amount of a therapeutic liquid composition  66  having a surface  66 S. (For clarity of the other first embodiment figures, liquid composition  66  is shown only in FIG. 5.) Preferably, the amount of liquid is in a range from about 1 to about 6 milliliters (ml). For a greater amount up to about 25 ml, a compressible cap with a higher profile than cap  22  should be used to provide greater displacement for developing a suitable dispensing pressure. Spindle  30  is closely received within socket bore  62 . Because cap portion  50  has not yet been depressed, socket end  60 E is disposed only about halfway down the spindle. Floor  28  includes a channel  68  in surface  28 S proximate to aperture  42  which ensures that even a small amount of liquid within the receptacle will be accessible to the aperture and thence the feeder tube. Aperture  42  is sealed by a dislodgeable “knockout” membrane  70 . As indicated by grooves  70 A,  70 B in FIGS. 5, 6 and  6 B, the membrane includes a peripheral annular thinned-out portion which contacts the receptacle wall. FIG. 6 depicts capsule  20  after portion  50  has been depressed, pre-pressurizing the capsule, tube end  44 B has been inserted into a pre-drilled hole  72 H in a tree trunk or plant stem  74 , aperture  42  has been slidably positioned over tube end  44 A, and a force  76  has been applied to surface  35  such that tube end  44 A dislodges membrane  70 . Spindle  30  is forced deeper into bore  62  so that end  60 E becomes proximate to floor  28 . Socket  60  is maintained in this position by an interference fit between surface  30 S and surfaces  64 A- 64 F. Tube end  44 A is adapted to dislodge membrane  70  circumferentially except at an upper end  70 U so that the membrane pivots inwardly (see FIG. 6B). Alternatively, a frangible membrane may be used with the tube end adapted for rupturing rather than dislodging the membrane. FIG. 6A shows how the cap attaches to the receptacle. Edge  23  includes generally parallel upper and lower lips  23 U,  23 L, respectively. Rim  25  includes an upper surface  25 S and a lip  25 L. Lip  23 U mates with surface  25 S, and lip  23 L mates with lip  25 L. Preferably, edge  23  and rim  25  are attached by ultrasonic welding. Suitable welders are manufactured by Branson Ultrasonics Corporation of Danbury, Conn. Preferably, capsule  20  is about 2¼ inches in length, 2⅛ inches in width, and 1⅜ inches in height.  
         [0037]    Referring to FIGS. 1, 7 and  8 , a plant injection capsule  100  according to a second embodiment of the invention includes a cap  102  having a circumferential, generally circular edge  103  hermetically sealed to a circumferential, generally circular rim  105  of a receptacle  104 . The cap and receptacle are attached as in the first embodiment (see FIG. 6A), preferably by ultrasonic welding. As shown in FIG. 7, receptacle  104  has an interior volume determined by a circumferential, generally cylindrical wall  106 , terminating upwardly in rim  105 , which is generally orthogonal to a generally planar floor  108  having an upper surface  108 S. Receptacle  104  further includes a housing  140  attached to wall  106  which provides a generally planar force application surface  142 . Attached to and depending upwardly from floor  108  and generally symmetric about its center of symmetry are first, second and third posts  110 A,  110 B,  110 C each having a hook-shaped upper portion  112  with a generally planar lower surface  112 S, and a lower portion  114  generally orthogonal to surface  112 S. As in the first embodiment, wall  106  includes an aperture  116  proximate to floor  108 .  
         [0038]    Referring to FIGS. 8 and 9, the top of cap  102  is identical to that of cap  22 ; i.e., the cap includes a rigid central portion  118  circumscribed by a plurality of concentric annuluses  120 A,  120 B,  120 C bridged consecutively pairwise, respectively, by a plurality of stepped ridges  122 A,  122 B,  122 C which enable the cap to flex inwardly. Depending downwardly from portion  118  is a generally cylindrical collar  124  having a bore  126  and a distally tapering end portion  128  terminating in an end  128 E. Portion  128  includes a circumferential groove  130  proximate to end  128 E which determines an annular lip  132  having a generally planar upper surface  132 S. FIGS. 9 and 10 depict capsule  100  in its initial (unpressurized) state, with end  128 E disposed slightly above the posts. (As in the first embodiment, receptacle  104  contains a preselected amount of liquid composition; for clarity this is not shown in any of the second embodiment figures. The preferred amount is in the same range as for the first embodiment.) As in the first embodiment, floor  108  includes a channel  134  in surface  108 S proximate to aperture  116 , and aperture  116  is sealed by a dislodgeable membrane  136 . As indicated by grooves  136 A,  136 B (see FIGS. 9 and 11), the membrane includes a peripheral annular thinned-out portion which contacts the receptacle wall. FIGS. 11 and 12 depict capsule  100  after portion  118  is depressed, pressurizing the capsule, aperture  116  is slidably positioned over feeder tube end  44 A after tube end  44 B is inserted into a tree trunk or plant stem (see FIG. 6), and a force  144  is applied to surface  142 , dislodging membrane  136 . Collar  124  is forced downward so that lower surfaces  112 S of posts  111 A,  110 B,  110 C engage surface  132 S. The resilience of the cap “living hinge” maintains the surfaces in locked combination.  
         [0039]    As in the first embodiment, preferably cap  102  and receptacle  104  are molded as single units from polypropylene or a similar thermoplastic, and most preferably from a clarified polypropylene copolymer such as Huntsman product P5M6K-048. Preferably, capsule  100  has the same dimensions as capsule  20 .