MXPA97007404A - A blockable security protection for a pre-filling syringe - Google Patents

Abstract

The present invention relates to a medical device comprising: a barrel having proximal and distal ends, a piercing element extending from the distal end of the barrel and having a distal tip, a collar positioned at the distal end of the barrel , the collar having one edge, and a guard mounted around said barrel and movable axially between a retracted position, wherein the distal tip of the piercing element is exposed, and an extended position, wherein the distal tip of the piercing element is covered, the protection having a proximal end, a distal end, and a circumferential side wall between them, the circumferential side wall having an outer surface and an inner surface; user-activatable locking means to ensure protection in the extended position, the means lockable by the user comprising by means a deflectable arm having a distal end with the circumferential side wall and a proximal end deflectable towards the inside of the guard, said at least one arm having a free position wherein the arm is coplanar substantially with the circumferential side wall of the guard, and a locked position, wherein the arm is deflected into said protection in such a way that the proximal end is placed towards the inside of the shield, at least one stop member mounted on the inner surface of the shield adjacent to the end of the shield for defining a space between the stop member and the proximal end of the deflectable arm, and a ring slidable axially about the outer surface of the shield between a first position wherein the ring is away from the at least one deflectable arm and a second position at where the ring is positioned against said at least one deflectable arm to secure the arm in the locked position ea

Description

A BLOCKABLE SAFETY PROTECTION FOR A PRE-FILLABLE SYRINGE Field of the Invention The invention relates to a lockable safety protection for a pre-filled syringe, and more particularly, to a lockable safety protection for a pre-filled syringe which It is presented in a form that allows easy assembly by a pharmaceutical manufacturer and which can be subsequently activated by an end user to form a blocking mechanism for protection. BACKGROUND As is known in the art, syringes are medical delivery devices usable for administering a medicament to a patient. The syringes are usually provided in pre-filled form, wherein a dose of medicament can be loaded into the syringe by a pharmaceutical manufacturer for distribution to the end user, or they are empty and for the purpose of being filled by the end user from a vial or another source of medication at the time when the administration of the medication is desired. The syringes typically include a barrel portion adapted to hold the medicament. The distal end of the barrel is normally configured to couple with a conventional piercing element, such as a pointed cannula-needle made of steel or similar material or a retro-end cannula formed of plastic, to deliver the medicament contained in the barrel. A plunger rod is inserted through the open distal end of the barrel of the syringe and, through its engagement with an elastomeric or rubber-like sealing element fitted in a fluid-tight manner within the barrel interior, a user can apply force manual to the plunger to deliver the medication through the piercing element. More typically the case with pointy needle cannulas, accidental needle sticks that occur after the needle cannula has been used generally pose a greater risk to health. To avoid such accidents, many hypodermic syringes of the prior art include a rigid cylindrical telescopic safety protection over the barrel of the syringe. The safety protection of the prior art can be slid from a proximal position where the needle-cannula is exposed for use, to a distal position where the safety protection surrounds the cannula-needle in a protective manner. Most hypodermic needles of the prior art with cylindrical safety shields telescoped on the barrel of the syringe include a structure for locking the safety shield in its distal position. Examples of such structures are found, for example, in the US Patents. Nos. 5,342,309 and 5,385,555 to Hausser and U.S. Patent No. 5,304,149 to Morigi. Although generally suitable for the tasks employed, additional improvements are still being visualized. For example, where the syringe is pre-filled by a pharmaceutical manufacturer, it would be beneficial to incorporate improvements in the blocking structure employed with the safety shields to further facilitate a processing by the pharmaceutical manufacturer of the various components associated with the barrel of syringe and the security protection. These improvements would also facilitate the normal end-user use of the pre-filled syringe and easy activation of the safety protection once the safe disposing of the syringe is desired. The present invention represents such improvement. Resoen of the Invention Lockable safety protection for pre-filled syringes is provided. The lockable safety protection is designed to facilitate an assembly of the pharmaceutical manufacturer of the various components associated with the lockable safety protection on the syringe in conjunction with how the syringes are normally processed by the pharmaceutical manufacturer. The blocking structure associated with the security protection of the present invention can be designed such that it will not interfere with easy assembly by the pharmaceutical manufacturer., but which can be easily activated by an end user to facilitate the safe covering of the distal end of a piercing element once the pre-filled syringe has been used. A collar is positioned around the distal end of the barrel of the syringe, and particularly configured to engage with the distal hub of a syringe barrel. The collar can be configured as a flat, disk-like structure with a central opening through which the hub is accommodated. Preferably, the collar is pre-fixed to the hub by the manufacturer of the syringe before delivering it to the pharmaceutical manufacturer. The security protection is mounted coaxially on the barrel of the syringe and the collar, and is movable axially between a retracted position, where the distal tip of the piercing element is exposed, and an extended position, where the distal tip of the piercing element It is covered. The security protection includes a proximal end, a distal end, and a circumferential side wall between them. The circumferential side wall has an outer surface and an inner surface. Particularly, the protection is provided with a blocking structure activatable by the user to ensure protection in its extended position with respect to the syringe. In one configuration, the blocking structure includes at least one deflectable arm incorporated as part of the structure of the side wall. The deflectable arm includes a distal end mounted with the circumferential side wall, and a proximal end which is deflectable towards the inside of the shield. At least one stop member is mounted on the inner surface of the shield and spaced a distance from the proximal end of the deflectable arm to define a space between the stop member and the proximal end of the deflectable arm. The deflectable arm has a free position, wherein the outer surface of the arm is substantially co-planar with the outer surface of the circumferential side wall, and a blocking position, wherein the deflectable arm is urged into the protection interior that the proximal end of the deflectable arm is placed towards the inside of the protection. Protection means are provided to activate the blocking structure. In one configuration, a circumferential ring is axially slidable about the outer surface of the guard between a first position, wherein the ring is remote from the deflectable arm, and a second position, wherein the ring is positioned against at least one arm deflectable to secure the arm in the blocking position. The ring may be secured to the distal end of the shield by a user-friendly connection. The user-breakable connection may involve, for example, one or more fragile sections of material provided between the ring and the distal end of the shield. A pair of spaced abutments may be provided on the outer surface of the deflectable arm to retain the ring in its second position. In practice, the collar is typically accommodated in the syringe barrel pre-filled by the syringe manufacturer and supplied to the pharmaceutical manufacturer in a sterile condition, ready to be filled with a desired medicament. After the syringe has been filled with a medicament and on the other hand subjected to various process operations, such as various particle inspection operations, labeling operations, rod-piston assembly operations, or the like, the protection can be easily adjusted to the syringe. The protection is slid proximally over the collar and barrel of the syringe to place it in a retracted position vis-a-vis the piercing element. Various structures associated with the protection, such as a stop member, can be provided with inclined surfaces to ensure smooth positioning of the protection on the collar. The blocking structure is activated by detaching the ring from its user-friendly connection., and sliding the ring proximally in such a way that it is coupled between the abutments provided in the deflectable arm. The device can be shipped by a pharmaceutical manufacturer to an end user with the ring connected to the protection through its user-friendly connection, so that the same end user activates the blocking structure. Alternatively and preferably, the pharmaceutical manufacturer activates the blocking structure as part of the assembly process, such that the filled syringe is shipped to an end user with the blocking structure already activated. After the syringe has been used to administer an injection, the guard is slid distally over the collar and barrel of the syringe. The collar will be captured between the proximal end of the deflectable arm and the stop member in order to lock the shield in its extended position. In a preferred embodiment, the deflectable arm, the collar, and the stop members may be configured to provide both audible and tactile indication to the end user that the protection has been securely locked with the collar. In a preferred embodiment, at least two deflectable arms are provided. The two deflecting arms are placed diametrically opposite sides of the protection. Correspondingly, two top members are provided to interact with the two deflectable arms. When viewed along the central axis of the guard, the stop members may be aligned circumferentially with a respective proximal end of the deflectable arms, or they may be circumferentially offset from a respective proximal end. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail by reference to the accompanying drawings, in: of: Figure 1 depicts, in perspective view, a lockable safety protection assembly of the present invention mounted on a syringe ? Figure 2 is an exploded perspective view of a lockable safety shield assembly of Fig. 1; Figure 3 is a sectional view of the lockable safety protection of the present invention being mounted in a syringe barrel subsequent to its filling by a pharmaceutical manufacturer; Figure 4 is a cross-sectional view of the lockable safety shield of the present invention subsequent to mounting on a filled syringe; Figure 5 is a cross-sectional view of the lockable security protection of the present invention after an end user has activated the blocking mechanism; Figure 6 is a cross-sectional view of the lockable safety shield of the present invention after it has been propelled in a distal direction by an end user to protectively cover the needle cannula; Figure 7 is a partial cross-sectional view of the bloggable security protection of the present invention illustrating the activation of the blocking mechanism; Figure 8 is a partial cross-sectional view of the lockable safety shield of the present invention interacting with the collaren the distal end of the barrel of the syringe; Figure 9 is a view of one end < ??? elevation of the lockable security protection according to the present invention; Y Figure 10 is a partial cross-sectional view of a preferred way of configuring the collar according to the present invention. Detailed Description of the Invention A convention used throughout this description is that the term "distal" refers to the furthest address of a practitioner, while the term "proximal" refers to the address closest to a practitioner. Turning now to the drawings, in which similar numerals denote similar components, Figs.2-4 represent one embodiment of a lockable safety protection assembly 30 in accordance with the present invention. The lockable safety protection assembly 30 according to the present invention can be provided in conjunction with a pre-filled syringe 10. Coo is illustrated in Figs. 1 and 2, the pre-filled syringe 10 includes a barrel 16 characterized by a proximal end 14, a distal end 12, and a hub 24 provided adjacent the distal end. A flange 18 may be provided around the proximal end, with a rod-piston 20 inserted through the proximal end 14. The plunger rod 20 is attached to a plug 22 used to drive the fluid through the barrel 16. The fluid is emitted or aspirated via a fluid passage, structured at the distal end 12 of the syringe, communicating with interior portions of the barrel 16. For example, if the pre-filled syringe is configured as a luer lock syringe, the fluid passage is configured as a luer tip (not shown) provided at the distal end 12. Here, the pre-filled syringe 10 is illustrated with a fluid passage configured as a piercing element 26, such as a pointed needle-cannula. The piercing element 26 is characterized by a distal end 28. The lockable safety protection assembly 30 according to the present invention includes a collar 32 and a safety shield 42. The collar 32 may be formed as a disc-like structure characterized by a edge 34, a side portion 36, and a central opening 38 therebetween. The collar 32 has a thickness "e" and is characterized by a maximum diameter "g". The central opening 38 is adjustable around the hub 24 and can be retained thereto by friction adjustment, adhesives, mechanical means, or similar structure, all known within the skilled artisan's field. If desired, the edge 34 may exhibit one or more raised pieces 39 having slots 40. The slots 40 may be aligned with complementary rails (not shown) provided on an interior portion of the security shield 42 to align the security protection during the assembly process. For purposes of clarity, Figs. 1-6 depict the collar 32 as having a rectangular cross section, with a side portion 36 exhibiting relatively flat walls that are attached directly to the edge 34. If desired, the collar 32 may be configured in this way to construct a lockable safety protection assembly according to the present invention. However, Fig.10 represents a preferred way to configure the collar (designated here by 32a) in this manner to provide a better audible and tactile indication that the shield 42 has been locked to the collar, as well as to improve the blocking action between the protection and the collar, as will be explained later. Referring now to Fjg.l0, as before, the collar 32a includes a edge 34 and a side portion 36. However, here, the side portion 36 is not completely flat. Rather, when viewed in cross-section, the edge 34 and the side portion 36 are joined by a blocking tooth 34a. The locking tooth 34a has a sloping edge 36a oriented distally and a sloping edge 36b oriented proximally. Each of the inclined edges 36a, 36b of the blocking tooth ends in a shelf 37 intersecting the side portion 36. As before, if desired, the slots (not shown) may be provided on the edge 34, for the purposes explained previously. As before, the collar 32a includes a thickness "e" and a maximum diameter "g". The blocking tooth 34a includes a maximum width "q" which need not be equal to the thickness "e" exhibited by the collar 32a. The security protection 42 is characterized by a proximal end 44, a distal end 45, and a circumferential side wall 46 therebetween. The circumferential side wall 46 includes an outer surface 48 and an inner surface 49. The outer surface 48 is characterized by a diameter "N". The shield 42 slidable on the collar 32, mounted on the hub 24, and on the barrel of the syringe 16 between a retracted position (Figs. 1, 4 and 5), wherein the distal tip 28 of the piercing element 26 is exposed, and an extended position (Fig. 6), wherein the distal tip of the piercing element is covered protectively. The lockable safety protection assembly 30 according to the present invention includes a user-activatable blocking structure. A feature of the lockable safety protection assembly according to the present invention is that the blocking structure can be implemented in such a way that it is not activated during the assembly of the components, making it easier to assemble the components to the syringe 10. Subsequent to Assembling the components, the blocking structure can be "activated", putting the safety protection assembly in a ready-to-use state. Referring to Figs. 1-3 and 7-9, the shield 42 has at least one deflectable arm 50. The arm 50 is preferably provided as part of the structure of the shield. The arm 50, which may be molded as part of the protection or subsequently created from the protection via various cutting processes, includes a distal end 54 and a proximal end 52. The distal end 54 is resiliently fixed to the side wall 46 such as by a live hinge arrangement, while the proximal end 52 is not attached to the side wall and is configured for free movement towards an inner portion of the shield 42. In a preferred embodiment, at least two deflectable arms 50 are provided in the protection 42, with these two arms placed on opposite sides diametrically of the shield 42. The arms 50 are thus configured for a free position (Figs 1 and 4), wherein the surface of the arms are substantially co-planar with the circumferential side wall 46 of the shield, and a blocking position (Figs. 5, 7 and 8), wherein the proximal ends 52 of the arms 50 are urged into the interior of the protection. As best reflected in Figs. 7 and 8, in a preferred configuration, the proximal ends 52 of the deflectable arms are not straight. Rather, to make better use of the features of the collar 32a (Fig. 10), the proximal ends 52 are preferably inclined in such a way that when the deflectable arms are placed towards the inside of the shield, the proximal ends will be oriented to cooperate blockably with the inclined edge 36a oriented distally of the collar 32a, as will be explained below. At least one stop member 70 is provided on the inner surface 49 of the guard in an area adjacent the proximal end 44. In a preferred embodiment, two stop members 70 are provided, each corresponding to one of the respective two arms deflectable 50 (see Fig. 9). The stop member 70 includes a stop surface 72 oriented distally. The abutment surface 72 is preferably spaced from the proximal end 52 of the deflectable arm at a distance "b" as measured along the central axis "z" of the guard (see Fig. 3). Coo is best illustrated in Figs. 7 and 8, in a preferred configuration, the abutment surface 72 is preferably not straight. Rather, to make better use of the features of the collar 32a (Fig.10), the abutment surface 72 is preferably inclined in such a way that it will cooperate blockably with the inclined edge 36b of the collar 32a, as will be explained below.

The stop member 70 also includes a sloped surface 74 oriented proximally. The inclined surface 74 oriented proximally facilitates the sliding of the shield 42 on the collar 32 when the guard is placed in its retracted position. The stop member 70 can be positioned such that the abutment surfaces 72 are aligned circumferentially with the respective proximal ends 52 of the deflectable arms 50, when viewed along the center axis "Z" of the shield. Alternatively, if desired, the stop members 70 may be positioned on the inner surface 49 of the shield such that they are circumferentially offset from the respective proximal ends 52 of the deflectable arms, when viewed along the "Z" central axis. of protection. The shield 42 includes a structure that allows activation of the deflection arms 50 to their locked position (Figs. 5, 6, 7, 8). A respective pair of distal and proximal abutments 58, 56 are provided in the deflectable arms 50. The distal abutment 58, which includes a sloping surface 60 oriented distally, is spaced from the proximal abutment 56 by a distance "a" defining a space 59 As seen in Figs. 3 and 4, in a preferred embodiment where two diametrically opposed deviating arms are included, the pair of diametrically opposed spaces 59 define a diameter "M" slightly larger than the diameter "N" defined by the outer surface 48 of the guard when the 50 arms are in their free position. The effect is that the space 59 is configured in such a way that it is raised from the level of the external surface 48 surrounding the cylindrical side wall 46 before the activation of the deflectable arm 50. A circumferential ring 80 having an inner wall 82 is disposed for coaxial movement with the circumferential side wall 46 of the shield. The inner wall 82 has a diameter "P" at least equal to, if not slightly less than, the diameter "N" defined by the outer surface of the shield 42. The ring 80 has a width of "d" at least equal to, if not slightly less than, the width of the space 59 as defined by the distance "a". To simplify assembly operations later by the pharmaceutical manufacturer, the shield 42 is typically supplied by the component manufacturer such that the ring 80 is configured together with the shield, with the ring retained in the shield 42, for example, by a connection breakable-by-the-user That is, the shield 42 and the ring 80 are preferably supplied to a pharmaceutical manufacturer as a single unit. For example, the ring 80 can be supplied by the component manufacturer such that it is secured to the protection by a user-friendly connection such as a threaded connection. Preferably, and as described herein, the ring 82 is secured to the distal end 45 of the shield by one or more user-configurable connections 84 configured as thin, brittle sections of material between the ring 80 and the end. 45 proximal protection. This type of structure also allows the component manufacturer to easily form the ring 80 and the shield 42 as a single molding. The shield 42 further includes a structure for retaining the shield 42 in the retracted position without being inadvertently over-retracted with respect to the syringe 10 and, therefore, inadvertently withdrawing it from the syringe 10 in the proximal direction. As seen in FIG. 3, one or more stop members 76 may be provided on the inner surface 49 of the shield adjacent the distal end 45. The distal abutment members 76 are configured to engage a lateral portion 36 oriented distally of the collar to prevent the shield 42 from being over-retracted in a proximal direction. If desired, one or more tertiary stop members 78 may be provided in the protection 42, each spaced from a respective distal stop member 76 by a distance "c" approximately equal to the thickness "e" of the collar 32. Therefore, the collar 32 can be releasably retained between the distal abutment members 76 and the members of tertiary stop 78 when the protection is in its retracted position. If desired, a tertiary stop member 78 can be provided with a proximally oriented inclined surface 79 which, like the proximally oriented inclined surface 74 associated with the stop members 70, assists in the assembly of the shield 42 around the collar 32. Now the operation of a device will be explained. Preliminarily, as has been explained, the collar 32 is typically pre-accommodated around the hub 24 by the syringe manufacturer. As also seen in Fig. 3, means may be adjusted to the syringe adjacent the distal end to provide a barrier to the passage of fluid leading to the medicament to be contained within the barrel 16. The barrier is normally accommodated by the manufacturer of the device. the syringe and here, can be adjusted to the barrel of the syringe in a process subsequent to the placement of the collar 32. If the fluid passage is structured as a luer tip, for example, a luer tip cap can be adjusted. Here, where a piercing element 26 is configured in the syringe, a well-known needle guard 29 can be fitted around the piercing element 26 in such a way that a proximal end of the needle shield 29 rests against the collar 32. The collar 32 should be configured such that the maximum diameter "g" is at least slightly greater than a maximum diameter "f" exhibited by the needle guard 29, such that the needle guard 29 will not interfere between the operation of the collar 32 and the protection 42. The syringe 10 is thus delivered to the pharmaceutical manufacturer in a sterile condition, ready to be filled with a desired medicament or otherwise processed in a well-known manner. For example, various filling operations, particle inspection operations, labeling operations, rod-piston assembly operations can be conducted on the syringe. After several filling and processing operations have been conducted, the protection 42 can then be adjusted to the syringe by the pharmaceutical manufacturer. The proximally oriented inclined surfaces 74 and, if provided, 79, assist the shield 42 to smoothly exceed the collar 34 of the collar. The shield 42 is slid over the barrel of the syringe 16 in a proximal direction, such that the collar 32 rests against the distal abutment members 76. If tertiary stop members 78 are provided, the collar 32 will be releasably retained between the limb members. distal stop 76 and the tertiary members 78, with the needle guard 29 attached to the piercing element 26. The syringe 10, together with the lockable safety protection assembly 30, can be shipped by the pharmaceutical manufacturer to an end user in a condition ready-to-use. Fig. 4 is representative of the security protection 42 of the present invention mounted around the syringe 10 prior to activation of the locking structure, while Fig. 5 is representative of the same construction after activation of the blocking structure. Preferably, a pharmaceutical manufacturer will ship the pre-filled syringe to the end user in a state shown in Fig. 5, such that the blocking structure is pre-activated by the pharmaceutical manufacturer, rather than by the same user. If the blocking structure is activated by a pharmaceutical manufacturer instead of an end user, it will be understood by the skilled artisan that the sliding step of the ring 80 into the space 59 can be effected as a final step in an assembly movement during the which protection 42 is accommodated to the pre-filled syringe. In this sense, it will also be understood that because the component manufacturer preferably supplies the ring and protection to the pharmaceutical manufacturer as a single unit, the assembly operations are simplified, because the pharmaceutical manufacturer only needs to be interested in ordering, orienting, distributing and then assemble a single unit around the syringe, instead of doing the same with a separate ring and protection. However, Fig.5 illustrates the activation of the blocking structure, either by the pharmaceutical manufacturer or by the end user. The user-breakable connections 84 connecting the ring 80 to the distal end 45 of the shield have been cut off, and the ring 80 has been slid proximally with respect to the shield 42. Aided by the associated distally oriented inclined surface 60. with the distal abutment 58, the inner surface 82 of the ring slides along the external surface 48 of the shield, on the inclined surface 60 oriented distally, and is secured in the space 59 defined between the distal abutment 58 and the abutment proximal 56. Because the inner diameter "P" of the ring 80 is larger than the diameter "M" between the diametrically opposed spaces 59, the ring 80 exerts an inwardly directed force on the deflectable arms 50. The deflectable arms 50 are thus deviated around their distal ends 54, such that the proximal ends 52 are pushed into the interior of the shield 42. As the deflectable arm 50 is driven inwardly (see particularly Figs. 7 and 8), the proximal end 52 of a deflectable arm and a given stop surface 72 of a respective stop element 70 define a space 100 therebetween. The space 100. is designed to "capture" the collar 32 when the guard is slid distally to cover the piercing element 26. Where the collar has a flat side portion 36, then the space 100 should have a width "b" at less equal, but slightly greater than, the thickness "e" of the collar to securely hold the collar 32 in the space 100. If, as described in Fig. 10, the collar is configured with a locking tooth 34a, then the width "b" should be chosen to accommodate the maximum width "q" associated with the locking tooth 34a, so that the locking tooth 34a is safely retained in the space 100. Ja Fig. 6 is representative of the protection 42 in its extended position to protectively cover the distal tip 28 of the piercing element. After the needle guard 29 has been removed and an injection administered in the usual manner, the shield 42 is held by an end user and slid distally with respect to the syringe 10. The collar 32, which is fixed to the hub 24, will be thus driven towards the proximal end 44 of 1 protection. Due to the resilience of the deflectable arms 50, the edge 34 of the collar will push the arms 50 in an outward direction from the inside of the shield and thus pass along the length of the arms 50. The edge 34 will eventually be deflected passing the proximal end 52, causing the arm to re-deviate in an inward direction towards the interior of the protection. Thus, the collar 32 will come to rest in the space 100, with the collar being between the proximal end 52 and the abutment surface 72. The collar 32 is thus held locked between the abutment surface 72 and the proximal end 52 of the arm, stopping further movement of the shield in any proximal or distal direction with respect to the syringe 10. Accordingly, the shield 42 is retained in its extended position with respect to the piercing element 26, covering the distal tip 28 protectively against contact by inadvertent touch. As previously explained, in a preferred configuration (Figs. 7, 8 and 10), the deflectable arms 50, stop members 70 and collar 32a are configured to provide a good audible indication thus tactile that the shield 42 has been locked to the collar 32a. As the edge 34 of the collar 32a clears the proximal end 52 of the deflectable arm, the locking tooth 34a enters the space 100. As soon as the locking tooth enters the space 100, the resilient characteristics of the deflectable arm cause the arm to be recessed. -discard in an inward direction towards the inside of the protection. At this time, an inner portion 49a of the deflectable arm 50 that is positioned adjacent the proximal end 52 is engaged against the ledge 37 of the collar 32a. As soon as the inner portion 49a is fitted against the shelf 37, tactile sensations so audible are transmitted to the user, noting that the guard 42 has been locked to the collar 32a. Due to the inclined orientations both, the proximal end 52 of the deflectable arms and the abutment surface 72 of the stop members 70, each of the proximal ends 52 and the abutment surfaces 72 are held locked against their respective inclined edge 36a distally oriented and the inclined edge 36b oriented proximally, such that the tooth 34a is securely locked within the space 100. Thus, by a simple distal movement, the shield 42 is self-locked with the collar 34a. The various components may be formed of suitable materials, such as medical grade plastics or the like. They can be injection molded in ways well known to the skilled artisan, resulting in reliable and cost-effective production of the blocking protection assembly. The blocking protection assembly of the present invention can be adapted to pre-filled syringes of various dimensions and capacities. Various improvements can be provided to allow easy assembly. For example, sections of the side wall adjacent to the proximal end of the shield may be thinned, or slits may be incorporated in an area of protection between the proximal end of the shield and the proximal edge of the deflectable arms, all to improve the easier gliding of the protection proximally on the collar. Of course, the dimensions of the various components can be selected in such a way that when the protection is in its retracted position, the distal tip of the piercing element is available for an injection, and when the protection is in its extended position, the distal tip of the perforating element will be covered protectively to allow the end user to safely discard the syringe. It will be appreciated and understood by those skilled in the art that further and additional revisions to the invention may be conceived without departing from the spirit and scope of the appended claims, the invention not being limited to the specific embodiments shown.

Claims (18)

1. A medical device comprising: a barrel having proximal and distal ends; a piercing element extending from the distal end of the barrel and having a distal tip; a collar positioned at the distal end of the barrel, the collar having one edge; and a guard mounted around said barrel and movable axially between a retracted position, wherein the distal tip of the piercing element is exposed, and an extended position, wherein the distal tip of the piercing element is covered, the guard having a proximal end, a distal end, and a circumferential side wall between them, the circumferential side wall having an outer surface and an inner surface; user-activatable locking means for securing the protection in the extended position, the locking means operable by the user comprising at least one deflectable arm having a distal end mounted with the circumferential side wall and a deflectable proximal end towards the inside of the shield, said at least one arm having a free position wherein the arm is coplanar substantially with the circumferential side wall of the shield, and a locking position, wherein the arm is deflected into said interior. protection in such a way that the proximal end is placed towards the inside of the shield, at least one stop member mounted on the inner surface of the shield adjacent the proximal end of the shield to define a space between the stop member and the shield. proximal end of the deflectable arm, and a ring slidable axially around the outer surface of the protection between a first position wherein the ring is remote from the at least one deflectable arm and a second position wherein the ring is positioned against said at least one deflectable arm to secure the arm in the locked position.

The medical device of claim 1, wherein said ring is secured to the distal end of the shield by a user-breakable connection in the first position, where an end-user can sever the reversible-by-wire connection. the user to axially slide the ring to the second position.

The medical device of claim 1, wherein the abutment member includes a proximally oriented inclined surface and a distally oriented abutment surface, the space defined between said abutment surface and the proximal end of said at least one deflectable arm. .

The medical device of claim 1, wherein said deflectable arm comprises a structure for retaining the ring in the second position.

The medical device of claim 4, wherein the structure to be retained comprises a distal abutment and a proximal abutment spaced from said distal abutment, wherein said annulus is retained in the space between said proximal and distal abutments.

The medical device of claim 5, wherein the space between said proximal and distal abutments is raised from the surface of said at least one deflectable arm, wherein said space is co-planar substantially with the circumferential side wall of the protection when said deflectable arm is in its blocking position.

The medical device of claim 5, wherein said distal abutment includes a distally oriented inclined surface wherein said annulus is urged on the inclined surface oriented distally of the abutment distal to said second position.

The medical device of claim 1, wherein said shield further comprises a second stop located on the inner surface of the shield adjacent the distal end, said second stop engageable with the collar when said shield is in its retracted position.

9. The medical device of claim 8, which further comprises a third stop placed on the inner surface of the protection proximally of the second stop, wherein the edge of the collar is retained between the second and third stops when said protection is in the retracted position.

10. The medical device of claim 1, wherein a locking tooth is provided on the edge of the collar.

The medical device of claim 10, wherein the proximal end of the at least one deflectable arm is oriented for locking engagement with the locking tooth of the collar.

12. A medical device, comprising: a barrel having proximal and distal ends; a piercing element extending from the distal end of the barrel and having a distal tip; a collar placed at the distal end of the barrel, the collar having a side portion and a circumferential edge; and a guard mounted around said barrel and movable axially between a retracted position, wherein the distal tip of the piercing element is exposed, and an extended position, wherein the distal tip of the piercing element is covered, said protection having a proximal end, a distal end, and a circumferential side wall between them, the circumferential side wall having an outer surface and an inner surface, the guard including user-lockable locking means to ensure protection in the extended position, the locking means activatable by the user comprising: at least one deflectable arm having a distal end mounted with the circumferential side wall, a proximal end deflectable towards the interior of the shield, and an outer surface between them, the proximal end of the deflectable arm defining a border for attach said collar, said at least one arm having a p free position wherein the outer surface of said arm is coplanar substantially with the circumferential wall of the protection, and a blocking position, wherein said arm is deflected into said protection so that said edge is placed towards the interior of the protection, said deflectable arm including a pair of abutments on the outer surface spaced apart from each other, at least one stop member mounted on the inner surface of the shield adjacent the proximal end of the shield to define a space between the shielding member. stop and the proximal end of the deflectable arm, and a ring retained in the protection by a breakable connection -by-the-user, said ring sliding axially around the outer surface of the guard between a first position wherein the ring is remote from the at least one deflectable arm and a second position wherein the ring is positioned between the pair of abutments in said at least one deflectable arm to secure the arm in the locked position, wherein the ring is slid proximally along the guard until the ring is positioned between the pair of buttresses, and the protection propelled further distally so that the circumferential edge of the collar enters the space defined between the stop member and the proximal end of the arm so that the edge of the arm engages the collar.

The medical device of claim 12, further comprising at least one slit in said circumferential intermediate side wall of the proximal end of the shield and the proximal edge of the deflectable arm.

The medical device of claim 12, wherein the user-breakable connection comprises one or more thin sections of material between said ring and the distal end of the shield.

The medical device of claim 2, wherein the user-breakable connection is one or more thin sections of material between said ring and the distal end of the shield.

16. A medical device comprising: a barrel having proximal and distal ends; a piercing element extending from the distal end of the barrel and having a distal tip; a collar placed at the distal end of the barrel, the collar having a border and a locking tooth defined on the edge; and a guard mounted around said barrel and movable axially between a retracted position, wherein the distal tip of the piercing element is exposed, and an extended position, wherein the distal tip of the piercing element is covered, the guard having a proximal end, a distal end, and a circumferential side wall between them, the circumferential side wall having an outer surface and an inner surface; user-activatable locking means for securing the protection in the extended position, the locking means operable by the user comprising at least one deflectable arm having a distal end mounted with the circumferential side wall and a proximal end inclined deflectable towards the inside of the lock for locking engagement with the locking tooth of the collar, the at least one arm having a free position where the arm is coplanar substantially with the circumferential side wall of the guard, and a locking position, wherein the arm is deflected into said protection so that the proximal end is positioned towards the inside of the shield, at least one stop member mounted on the inner surface of the shield adjacent to the proximal end of the shield and having an inclined abutment surface, the stop member placed in the guard to define a space within e the inclined abutment surface and the inclined proximal end of the deflectable arm, and a ring slidable axially about the outer surface of the shield between a first position wherein the ring is remote from the at least one deflectable arm and a second position wherein the ring is positioned against said at least one deflectable arm to secure the arm in the locked position, where after the ring has been placed in the second position, the protection is driven distally so that the locking tooth enters in the space between the inclined stop surface and the inclined proximal end of the arm to block the tooth in space.

The medical device of claim 16, wherein an audible indication is produced when the locking tooth enters the space.

18. The medical device of claim 16, wherein a tactile indication is produced when the locking tooth enters the space. Summary Lockable safety protection is provided for a pre-filled syringe. The design of lockable safety protection improves the ability of pharmaceutical manufacturers to assemble the various components as part of their filling or processing of pre-filled syringes in normal practice. A collar is adhered to the distal hub of the pre-filled syringe. A safety shield is axially slidable over the collar between a retracted position, wherein the distal end of the piercing element associated with the pre-filled syringe is exposed and an extended position, wherein the safety shield is locked to the collar to protectively cover the distal end of the piercing element. The safety protection includes a locking structure configured so that the protection, when supplied to the pharmaceutical manufacturer, can be easily accommodated to the syringe. The locking structure includes at least one deflectable arm provided in the body of the protection. The deflectable arm includes a proximal end that can be deflected towards the inside of the shield. A stop member is provided on the inside of the guard in spaced relation to the proximal end of the deflectable arm. A ring is slidable axially on the protection to divert the arm towards the inside of the protection to activate the blocking structure. The security protection is slid distally by an end user such that the collar is held locked between the stop member and the proximal end of the deflectable arm. The collar, the stop member, and the deflectable arm can be configured to provide both tactile and audible locking indication to the end user.