Abstract:
A cap assembly mountable to a rigid shield around a needle of a syringe. The cap assembly includes a gripper component and a base cap. The gripper component includes a support frame and a liner that is deformable when sandwiched between the support frame and the rigid shield. When the base cap is installed to the gripper component during manufacture, and with the rigid shield disposed in a bore of the gripper component in any rotational orientation relative thereto, the liner is held by the support frame so as to be deformed against and grip the rigid shield for shield removal purposes so as to allow for removal of the rigid shield from around the needle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention pertains to pharmaceutical injection devices, and, in particular, to a cap assembly for removing a rigid shield that protects a needle of a syringe. 
         [0002]    Many automatic injector devices include a cap feature which when removed from the device removes a protective shield from a needle of the syringe of the device. The protective shield may consist of a multipart construction including an inner shield and an outer shield which are operatively connected together. The inner shield is relatively flexible or elastomeric and provides a sterile barrier around the needle and forms a seal with, for example, the syringe hub from which the needle extends. The inner shield also may seal the tip of the needle such as in designs where the needle is already in fluid communication with the syringe contents. The outer shield is made of a relatively rigid material and protectively surrounds and engages the inner shield. A pulling of the outer or rigid needle shield from the syringe pulls off the inner shield as well. 
         [0003]    The cap feature of the device grips the rigid needle shield and serves to make easier the removal of the shield. The cap feature may be larger in diameter than the protective shield, or provided with a mechanical advantage to aid its removal, so as to be more readily grasped and removed by certain users than if the protective shield was removed alone. When the cap feature is removed from the device, which removal removes the protective shield as well due to the cap gripping the rigid needle shield, the needle is uncovered, although frequently still housed within the device prior to being extended therefrom during use, and ready for an injection. 
         [0004]    One known cap feature that grips a rigid needle shield utilizes a two-piece assembly. The first piece includes a plastic cup with a tubular portion designed to fit over a rigid needle shield portion of a protective shield previously mounted to an injection needle. The second piece includes a larger diameter, rigid plastic base cap having a softer, grippable periphery that may be provided via a comolding or two shot molding process. Two openings formed through sides of the tubular portion of the plastic cup define a pair of diametrically opposed grip fingers that are resilient so as to be deflectable. Each finger has an inner surface with serrated ribs, and an outer surface with a ramp formed thereon. After the plastic cup is placed onto the rigid needle shield such that the serrated ribs of the resilient fingers are in angular alignment with detents on the rigid needle shield with which they cooperate, the base cap is mounted to the plastic cup so that the tubular portion of the cup inserts into a cavity of the base cap. During this insertion, the base cap interior surface that defines its cavity engages the ramps of the grip fingers to deflect the fingers inward such that the serrated ribs come into gripping contact with the rigid needle shield. The base cap is so mounted until its radial protruding tabs within the base of the cavity snap fit into an annular recess on the exterior of the cup tubular portion, thereby locking the base cap and the plastic cup together to allow them to function as a unit. 
         [0005]    While such cap assemblies for removing rigid needle shields may provide a benefit to users, these cap assemblies may complicate the manufacture process. For example, mounting the cap assemblies requires a rotational orientation step to ensure the parts of the rigid needle shield and the cup which cooperate are angularly aligned. Such requires consideration during the manufacturing process, and if unsuccessfully performed may result in an unsatisfactory gripping of the rigid needle shield. 
         [0006]    Thus, it would be desirable to provide cap assembly that can overcome one or more of these and other shortcomings of the prior art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    In one form thereof, the present invention provides a cap assembly mountable to a rigid shield around a needle of a syringe, the cap assembly including a gripper component and a base cap. The gripper component is for directly engaging the rigid shield. The gripper component includes a support frame and a liner. The support frame defines an interior hollow. The liner is secured to the support frame within the interior hollow to provide a gripping section that defines a bore sized to axially receive the rigid shield. The liner is formed of a material that is resilient relative to a material forming the support frame and is deformable when sandwiched between the support frame and the rigid shield. The base cap is grippable by a user and includes a body having a surface defining a cavity for accommodating the gripper component. The body surface is configured to compress the gripper component from a first arrangement to a second arrangement when the gripper component inserts within the cavity during manufacture. The liner, when the gripper component is disposed in the first arrangement, does not grip for shield removal purposes the rigid shield when disposed in the bore. The liner, when the gripper component is disposed in the second arrangement with the rigid shield disposed in the bore in any rotational orientation relative thereto, is held by the support frame so as to be deformed against and grip the rigid shield for shield removal purposes so as to allow for removal of the rigid shield from around the needle. 
         [0008]    One advantage of the present invention is that a cap assembly may be provided which can be mounted to a rigid needle shield without the portion that directly engages the rigid needle shield being in a particular angular orientation. 
         [0009]    Another advantage of the present invention is that a cap assembly may be provided which can function within a range of axial tolerances at which the rigid needle shield can be presented for gripping. 
         [0010]    Another advantage of the present invention is that a cap assembly may be provided which, due to its gripping of a rigid needle shield at a point below a hole in a housing baseplate of a device through which a syringe needle extends, allows that hole in the housing baseplate to be made smaller than it would be if the cap assembly were to protrude into the hole. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The above-mentioned and other advantages and objects of this invention, and the manner of attaining them, will become more apparent, and the invention itself will be better understood, by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0012]      FIG. 1  is a front view of an automatic injection device equipped with a rigid needle shield gripping cap assembly of the present invention; 
           [0013]      FIG. 2  is a view of the device of  FIG. 1  in partial longitudinal cross-section further revealing the cap assembly of the present invention; 
           [0014]      FIG. 3  is a top perspective view of only a completely manufactured gripper component of the cap assembly of the present invention in its neutral state; 
           [0015]      FIG. 4  is a bottom perspective view the gripper component of  FIG. 3 ; 
           [0016]      FIG. 5  is a front view of the gripper component of  FIG. 3 ; 
           [0017]      FIG. 6  is a side view of the gripper component of  FIG. 3 ; 
           [0018]      FIG. 7  is a top view of the gripper component of  FIG. 3 ; 
           [0019]      FIG. 8  is a longitudinal cross-sectional view of the gripper component taken along line  8 - 8  of  FIG. 7 ; 
           [0020]      FIG. 9  is a longitudinal cross-sectional view of the gripper component taken along line  9 - 9  of  FIG. 7 ; 
           [0021]      FIG. 10  is a bottom view of the gripper component of  FIG. 3 ; 
           [0022]      FIG. 11  is a top view of the support frame of the gripper component of  FIG. 3  prior to an elastomeric liner being overmolded thereto; 
           [0023]      FIG. 12  is a side view of the support frame of  FIG. 11 ; 
           [0024]      FIG. 13  is a bottom view of the support frame of  FIG. 11 ; 
           [0025]      FIG. 14  is a longitudinal cross-sectional view of the support frame taken along line  14 - 14  of  FIG. 11 ; 
           [0026]      FIG. 15  is a longitudinal cross-sectional view of the support frame taken along line  15 - 15  of  FIG. 11 ; 
           [0027]      FIG. 16  is a top perspective view of a completely manufactured base cap of the cap assembly of the present invention; 
           [0028]      FIG. 17  is a top view of the base cap of  FIG. 16 ; 
           [0029]      FIG. 18  is a is a longitudinal cross-sectional view of the base cap taken along line  18 - 18  of  FIG. 17 ; 
           [0030]      FIG. 19  is perspective view of a step in assembling the inventive cap assembly to a rigid needle shield of an automatic injection device; 
           [0031]      FIG. 20  is perspective view similar to  FIG. 19  at a subsequent step; and 
           [0032]      FIG. 21  is perspective view similar to  FIG. 20  after the assembly is complete. 
       
    
    
       [0033]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent an embodiment of the present invention, the drawings are not necessarily to scale, and certain features may be exaggerated or omitted in some of the drawings in order to better illustrate and explain the present invention. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    In  FIGS. 1 and 2 , a first embodiment of a cap assembly of the present invention, generally designated  20 , is shown mounted to an automatic injection device, generally designated  200 . The cap assembly  20  is formed of an inner part or gripper component, generally designated  25 , and an outer part or base cap, generally designated  30 . Cap assembly  20  serves as a means for gripping a rigid needle shield to allow a user to conveniently remove a needle shield that protectively surrounds a needle  220  of a syringe of device  200  in order to prepare that device for use. Device  200  does not form a part of the present invention, but may be, for example, an automatic injection device as disclosed in PCT international patent application entitled “Trigger Assembly for an Automatic Injection Device”, filed with the United States Patent and Trademark Office as Application No. PCT/US2013/064476, the entire disclosure of which is incorporated herein by reference. 
         [0035]    With additional reference to  FIGS. 3-10 , gripper component  25  is shown in its neutral or unstrained state prior to being used with base cap  30  to grip a rigid needle shield. Gripper component  25  has a cup-like overall shape with a proximal end  32  and a distal end  34 . Gripper component  25  is formed from a support frame, generally designated  40 , and a liner, generally designated  80 , which is comolded with frame  40  within its interior hollow  41 . 
         [0036]    Support frame  40  is a single piece injection molded out of a relatively rigid and durable material such as glass filled polypropylene. As further shown in  FIGS. 11-15 , support frame  40  includes a base formed of a pair of diametrically opposed, arc-shaped base sections  42 ,  44 . Each of base sections  42 ,  44  includes a groove  46  along its outer radial periphery. The opposite ends of base sections  42 ,  44  are angularly spaced to provide gaps  47 . Gaps  47  allow the base sections  42 ,  44  to be moved closer to each other in situations where forcibly inserted into a bore that is smaller in diameter than the maximum extent of the uncompressed support frame  40 . 
         [0037]    Base section  42  also includes a lobe  70  protruding radially at its distal end into the circular opening  72  that would otherwise be generally defined by base sections  42 ,  44 . An axially projecting, convex region  76  is formed in lobe  70  at the axial center of the gripper component  25 . 
         [0038]    Two pairs of solid flanges  50  that are diametrically opposed from each other extend from base sections  42 ,  44 . Another pair of diametrically opposed, apertured flanges  52  also extend from base section  42 ,  44  between the pairs of solid flanges  50 . Each apertured flange  52  is defined by a tapering, interior opening or slot  54  and spans opposite ones of the gaps  47 . Slots  54  can partially close when base sections  42 ,  44  are forced inward so as to decrease gaps  47 . 
         [0039]    For the orientation of gripper component  25  in  FIGS. 3-9 , flanges  50  and  52  taper in angular extent as they extend upward. Flanges  50  and  52  also splay radially outward as they extend upward so as to circumscribe a larger area whereby proximal end  32  has a larger diametric extent than does distal end  34 . Due to their plastic construction and their thinness in the radial direction, flanges  50  and  52  can flex inward when the flanges are cammed inward as described further below. 
         [0040]    The end faces  58  of flanges  50  include upstanding tabs  60 , and the end faces  64  of apertured flanges  52  include similar but slightly larger tabs  66 . Tabs  60  and  66  are set-offs or points of contact with the device housing end plate. 
         [0041]    With reference again to  FIGS. 3-9 , the liner  80  is molded as part of a two shot molding process directly to the support frame  40  out of a material that is relatively resilient or compressible compared to the material of the support frame  40 . One suitable material is a thermoplastic elastomer known as Santoprene®. Liner  80  can conform to and frictionally engage the outer radial periphery of the rigid needle shield that it is intended to grip. 
         [0042]    The overmolding liner  80  rings completely the inner radial periphery of support frame  40  other than the lobe  70 . Liner  80  is not only adhered via its comolding with the inner radial surfaces  82 ,  84  and  86  of flanges  50 , flanges  52  and base sections  40 ,  42  respectively, but also fills the angular space between, and adheres via comolding to, the angular side faces  90 ,  91  of flanges  50  and  52  respectively. Slots  54  and gaps  47  are not filled by the liner  80  so as to not prevent radial compression of flanges  52  and base sections  42 ,  44  as described above. 
         [0043]    Liner  80  forms a substantially annular shape defining a central throughhole or bore  95 . The liner interior surface  97  that forms the bore  95  inward of the flanges  50  and  52  is a gripping section that tapers in diameter as it extends distally. The liner interior surface  99  that forms the bore  95  inward of the base sections  42 ,  44  has a smaller taper in diameter as it extends distally. The tapering configuration of the bore  95  results in the proximal end of the bore being larger in diameter than the distal end of the bore, and this configuration, as well as the chamfered proximal end face  87  of liner  80 , can facilitate placement of the gripper component  25  over a rigid needle shield. 
         [0044]    The tapering of the liner bore diameter results in an angled configuration relative to the axial direction that is less pronounced than the angle at which flanges  50 ,  52  splay outward such that liner  80  has a radial thickness that is greater at the proximal end than at the distal end. 
         [0045]    The bore  95  of liner  80  is dimensioned by the manufacturer in view of the rigid needle shield with which cap assembly  20  will be used. Bore  95  along its axial length is typically slightly larger in diameter than the rigid needle shield such that the gripper component  25 , when in its neutral or ready arrangement shown in  FIG. 3 , can be freely placed over that rigid needle shield, or in other words without any compression of the liner  80  being required. In such case the gripper component  25 , before being engaged by the base cap  30  during manufacturing assembly, could be removed easily from the rigid needle shield without potentially disturbing the rigid needle shield and the needle it surrounds. The bore  95  may also be sufficiently smaller in diameter as to require a minimal amount of force against liner  80  be provided by the rigid needle shield when inserted into bore  95 , so long as assembly or removal of the gripper component, if such is desired to be done during manufacturing assembly before the base cap  30  is attached, does not disturb the relationship of the needle and needle shield. 
         [0046]    The bore  95  of liner  80  is also dimensioned by the manufacturer in view of the camming relationship of the gripper component  25  with the cap assembly  30 , such that liner  80 , when cap assembly  30  is connected to gripper component  25 , is compressed around the rigid needle shield to provide a grip of the rigid needle shield sufficient for it to be able to pull the protective needle shield off the syringe needle when desired. 
         [0047]    The cap assembly base cap  30  is further shown in  FIGS. 16-18 . Base cap  30  is formed of a two shot molding having a central body portion  100  and a gripping periphery  102 . Body portion  100  is formed of a rigid material such as polycarbonate. Periphery  102  is molded onto body portion  100  out of a softer material, such as a thermoplastic elastomer such as Santoprene®, and includes knurling  104  to make it easier to grip and directional arrows  106  to show how it can be twisted for removal from the device. 
         [0048]    Body portion  100  includes a central cavity  110  defined by a generally cylindrical surface region  112  with a chamfered lead-in surface  114 . Surface region  112  is designed to fit around gripping component  25  when placed thereover, but is sized and shaped to bend or cam inward the flanges  50 ,  52  from the ready arrangement shown in  FIGS. 3-10  to a radially compressed, operational arrangement shown in  FIG. 2  to create a shield gripping configuration described further below. Three equally angularly spaced tangs  118  inwardly project within cavity  110  near its base. Ramped proximal faces  120  of tangs  118  aid in tangs  118  inserting into groove  46  during the connection of base cap  30  to gripper component  25 . 
         [0049]    Three cams  125  that are equally angularly spaced around cavity  110  and which are arcuate in shape project upwardly from the proximal surface  126  of body portion  100 . Cams  125  fit within arcuate slots  131  provided in the base plate  130  of the device housing show in  FIG. 2 . A detent  127  provided on each of cams  125  engages base plate  130  to provide a releasable connection of body portion  100  to the base plate to aid in keeping cap assembly  20  on device  200  until its removal as desired. The camming engagement of cams  125  with base plate  130  when a user rotates cap assembly  20  relative to the rest of device  200  in the direction of arrows  106  shifts the cap assembly  20  away from the rest of the device, overcoming the connection of detents  127  with the base plate  130 , to facilitate cap removal. The removal of the cap assembly  20  from device  200  may also be done without rotation of the cap assembly but merely by the user pulling it axially. 
         [0050]    The structure of cap assembly  20  will be further understood in view of the following description of its assembly to a device by a manufacturer. In  FIG. 19 , injection device  200  is shown prepared for the attachment of cap assembly  20  to the rigid needle shield  210  of the device shown projecting beyond base plate  130 . The inventive cap assembly can engage rigid needle shields of various shapes known in the art, including those which lack recesses or protrusions that liner  80  can fit into or around. The shown rigid needle shield  210  has a generally cylindrical, projecting end region  212  with longitudinal slots  214  spaced around the circumference through which an elastomeric inner shield  216  is visible. Inner shield  216  seals the end of a needle  220  of a syringe  222  within device  200  as further shown in  FIG. 2 . Rigid needle shield  210  and inner shield  216  are interconnected at  217  so that the protective shield they provide together around the end of needle  220  is removable as a unit. 
         [0051]    Assembly of the cap assembly  20  to rigid needle shield  210  begins with maneuvering a gripper component  25 , in its neutral state, into a position axially above the rigid needle shield  210  as shown in  FIG. 19 , and then moving it down as indicated by arrow  230  such that rigid needle shield  210  inserts into liner bore  95 . This insertion ends when the flange offsets  60 ,  66  abut the base plate  130 . While alternatively this insertion could end when the tip of rigid needle shield  210  abuts lobe  70 , such is less desired as this transmits forces to the needle shield. Gripper component  25  advantageously need not be in any particular rotational orientation relative to shield  210 . 
         [0052]    Base cap  30  is then brought into a position axially above the gripper component  25  resting over the rigid needle shield  210 , and moved down as indicated by arrow  235  in  FIG. 20  such that the gripper component  25  inserts within cavity  110  of base cap  30 . Initially during this insertion, no resistance is met as the base of gripper component  25  first freely inserts within cavity  110 . As the insertion continues, however, cavity surface  112  at chamfered lead-in surface  114  encounters the outer radial peripheries first of base sections  42 ,  44  and then flanges  50  and  52 , which base sections and flanges outwardly extend beyond the diameter of cavity  110 . The downward axial movement of base cap  30  causes base sections  42 ,  44  and flanges  50 ,  52  to be cammed inward by their engagement with the surface  112 , and this camming forces liner  80  against the rigid needle shield  210  so as to be sandwiched between shield  210  and flanges  50  and  52 , and between shield  210  and bore surface  112  in the angular spaces between the flanges. When so sandwiched, liner  80  conforms to the periphery of the rigid needle shield  210  to provide a tight grip thereof. The insertion of gripper component  25  is halted after the base cap tangs  118  snap fit into groove  46  of base sections  42 ,  44 , which snap fit ensures that base cap  30  and gripper component  25  are locked together to allow them to function as a unit for shield removal purposes. Frictional forces between surface  112  and the outer periphery of the flanges  50 ,  52  prevent rotation of the gripper component within base cap  30 , but need not so act within the scope of the invention. At this point, cap assembly  20  is securely attached to device  200  as shown in  FIG. 21  as well as  FIGS. 1 and 2 . When the device needle is to have its protective shield removed for use, the cap assembly  20  is simply removed from device  200 , which pulls off the gripped rigid needle shield  210  and the inner shield  216  that the rigid needle shield holds. 
         [0053]    While this invention has been shown and described as having preferred designs, the present invention may be modified within the spirit and scope of this disclosure. For example, while the liner is described as being overmolded to the support frame as a two part process, the liner could be separately formed and then securely attached to the support frame. This application is therefore intended to cover any variations, uses or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.