WO2020039009A1

WO2020039009A1 - Shield remover for a syringe

Info

Publication number: WO2020039009A1
Application number: PCT/EP2019/072403
Authority: WO
Inventors: Hans Hemmingsen; Frederik HOLTEN-TINGLEFF
Original assignee: Novo Nordisk AS
Current assignee: Novo Nordisk AS
Priority date: 2018-08-21
Filing date: 2019-08-21
Publication date: 2020-02-27
Anticipated expiration: 2021-02-21

Abstract

A shield remover for removing a needle shield (150/155) from a syringe (100), comprising: (a) an outer cap (350) having a tubular skirt member (352) arranged coaxially with the needle shield of the syringe (100), (b) an intermediary component (250) coupled between the outer cap (350) and the needle shield (150/155), the intermediary component (250) comprising a shield engagement grip means (254) for coupling the intermediary component (250) with the needle shield (150/155), and (c) a lock member (280). The outer cap (350) and the intermediary component (250) comprise a series of axially disposed detents (257) formed on one of the outer cap (350) and the intermediary component (250), and a retaining protrusion (357) formed on the other of the outer cap (350) and the intermediary component (250), wherein the retaining protrusion (357) is selectively engageable with each one of the series of axially disposed detents (257). The lock member (280) is configured for being received by the outer cap (350) and movable to a position wherein it maintains locking engagement between the retaining protrusion (357) and the selectively engaged one of the series of axially disposed detents (257).

Description

SHIELD REMOVER FOR A SYRINGE

The present invention relates to shield remover for a syringe for injecting one or more doses of a liquid drug. In particular the present invention relates shield removers and methods for providing easy assembling a shield remover with a syringe having a needle shield.

BACKGROUND

In conventional handheld medical injectors standard prefilled syringes are often used for primary packaging. In order to provide particular functions for the medical injector, or to provide ease of handling and protection for the syringe, prefilled syringes are often accommodated in a medical injector typically incorporating an outer housing which holds an expelling mechanism.

Often, such injection devices are required to work with sealed hypodermic syringes which typically have a hermetically sealed shield or "boot" that covers the hypodermic needle and maintains the sterility of the syringe contents. The boot may be formed from a rubber material, and may further be encapsulated in a rigid needle shield (RNS). Naturally, it is necessary to maintain the sterility of the syringe contents up to the point of administration, which means that the needle shield must be removed with the syringe inside the injection device.

Typically, the action required to remove the needle shield from the syringe entails either pulling the needle shield away from the syringe or twisting the needle shield and pulling it away from the syringe. If a prefilled syringe has been stored for quite a while before it is used, it is often difficult to remove the needle shield from the syringe; a substantial force is often required.

Example disclosures of couplings between an outer cap of an injection device and a needle shield of a syringe accommodated in the injection device are provided in US 9,333,305 B2, US 9,339,610 B2, and EP 2 255 842 B1.

The injection device may be designed so that removal of an outer cap of the injection device also removes the needle shield from the syringe. In such cases, the needle shield must be connected to the outer cap in such a way that the force required to remove the needle shield from the syringe is less than the force required to disconnect the needle shield from the outer cap. In order to connect the needle shield to the cap, an "insertion" force is exerted on the syringe. If this insertion force is too high, damage to the syringe and/or needle shield will occur, and the injection device will fail to operate correctly. The force required to remove a needle shield from a syringe is generally an order of magnitude greater than the maximum insertion force that can be exerted on the syringe via the needle shield without causing damage to the needle shield and/or syringe.

Therefore, there is a need for a means for connecting an outer cap of an injection device to a needle shield of a syringe in such a way that removal of the outer cap from the injection device causes removal of the needle shield from the syringe, and connection of the outer cap to the needle shield exerts a minimal force on the syringe and/or needle shield. There is further a need for a means of connecting an outer cap of an injection device to a needle shield of a syringe in a manner which is able to take up large axial tolerances.

SUMMARY

It is an object of the present invention to provide an improved shield remover for a syringe and which enables improved manufacturability. A further object of the present invention is to provide a shield remover coupling between an outer cap and a needle shield, which, during assembly operations, does not alter or modify the needle shield position on the barrel of a syringe.

In the disclosure of the present invention, embodiments and aspects will be described which will address one or more of the above objects or which will address objects apparent from the below disclosure as well as from the description of exemplary embodiments.

In a first aspect, the present invention relates to shield remover for removing a needle shield from a syringe, comprising: (a) an outer cap comprising a tubular skirt member arranged along a central axis for enclosing the needle shield coupled to the syringe, (b) an intermediary component coupled between the outer cap and the needle shield, the intermediary component comprising a shield engagement mechanism for coupling the intermediary component with the needle shield so that when the shield remover is pulled away from the syringe, the intermediary component exerts force against the needle shield to remove the needle shield from the syringe, and (c) a lock member. The outer cap and the intermediary component comprises at least one pair of engaging mechanisms, each pair of engaging mechanisms comprising a series of axially disposed detents formed on one of the outer cap and the intermediary component, and a retaining protrusion formed on the other of the outer cap and the intermediary component, wherein the retaining protrusion and the series of axially disposed detents are configured for resiliently moving into engagement with each other so that said retaining protrusion selectively engages one of said series of axially disposed detents, and

wherein the lock member is configured for being received by the outer cap and movable between a first position and a second position, wherein the lock member in the first position allows said resilient moving into engagement of the retaining protrusion and the series of axially disposed detents, and wherein the lock member in the second position cooperates with the outer cap and/or the intermediary component to maintain locking engagement between the retaining protrusion and the selectively engaged one of the series of axially disposed detents.

Such shield remover provides for a reliable coupling between the outer cap and the needle shield, such as an RNS, of a held syringe, where the coupling is able to adapt between components having comparatively large tolerances. The shield remover solution provides superior manufacturability for enabling low-cost manufacturing and assembly in an automatic assembly line. At the same time, the adaptive nature of the coupling ensures that the risk of compromising sterility in the sealing interface between the needle shield and the syringe barrel is reduced.

In some embodiments said resiliently moving into engagement includes a radial movement towards or away from said central axis.

For each pair of engaging mechanisms, one of the retaining protrusion and the series of axially disposed detents may be formed on a longitudinally extending resilient arm, the longitudinally extending resilient arm being radially movable when the lock member assumes the first position.

In some forms the longitudinally extending resilient arm is formed by the outer cap.

In other forms the longitudinally extending resilient arm is formed by the intermediary component. In some embodiments the lock member includes a blocking geometry for each pair of engaging mechanisms, said blocking geometry engaging a respective one of the longitudinally extending resilient arms when the lock member assumes the second position to maintain locking engagement between the retaining protrusion and the selected one of the series of axially disposed detents.

In further embodiments, the outer cap defines a distal end surface and an outer circumferential skirt extending proximally from the distal end surface, and wherein respective ones of said longitudinally extending resilient arms connects to the distal end surface radially inwards from the outer circumferential skirt.

In some forms of the shield remover, the distal end surface of the outer cap includes at least one aperture configured to allow the lock member to be inserted in proximal direction through the aperture.

The lock member may be formed to include a distal end face that lies flush with the distally end face of the outer cap when the lock member assumes the second position.

In some forms of the shield remover the lock member comprises a colour coding which represents the type or kind of drug accommodated in the syringe.

In further embodiments the shield engagement mechanism defines a shield engagement grip means. The shield engagement grip means may be formed to comprise at least one radially flexible grip member defined by the intermediary component, and wherein the radially flexible grip member is configured for snapping engagement with an engagement geometry of the needle shield. In some embodiments, the engagement geometry of the needle shield is provided as a proximally facing surface, such as a substantially proximally facing edge surface that neighbours a radial recess formed in the radially outwards facing surface of the needle shield. In other embodiments, the engagement geometry of the needle shield is provided as a proximally facing surface of a circular flange or circular rim, such as the cylindrical proximal end surface of the needle shield. In some forms the needle shield of the syringe is provided as a rigid needle shield (RNS) which may comprise a rigid outer surface and an elastomeric inner surface which couples to the barrel of a syringe. In a second aspect, the present invention relates to an assembly comprising a shield remover in accordance with the first aspect, and a syringe having a needle shield attached.

In a third aspect, the present invention relates to a medical injector comprising a shield remover in accordance with the first aspect, and a syringe having a needle shield attached.

In some forms the needle shield defines a radial outwards facing surface comprising one or more radial apertures or recesses, and wherein the shield engagement mechanism includes at least one grip member each locking into a respective one of said one or more radial apertures or recesses.

In some forms of the medical injector the medical injector comprises a housing wherein a wave shaped interface is provided between the housing and the outer cap, the wave shaped interface being configured to axially move and separate the outer cap from the housing as the outer cap is twisted relative to the housing.

As used herein, the term "drug" is meant to encompass any drug-containing flowable medicine or combinations of separately held plurality of drug-containing flowable medicines capable of being passed through a delivery means such as a cannula or hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension.

BRIEF DESCRIPTION OF DRAWINGS

In the following the invention will be further described with reference to the drawings, wherein figs. 1a and 1 b show cross sectional front and side views of an example auto-injector suitable for use with the present invention,

fig. 2 shows a perspective side view of a prior art standard prefilled syringe 100,

figs. 3a and 3b show cross sectional front and side views of a first embodiment of a shield remover in combination with a medical injector,

figs. 3c, 3d, and 3e respectively show a perspective view of an insert of the first embodiment, a perspective cross sectional view of an outer cap of the first embodiment, and a perspective cross sectional view of the outer cap of fig. 3d with multiple inserts of fig. 3c inserted, figs. 4a and 4b show cross sectional front and side views of a second embodiment of a shield remover in combination with a medical injector, figs. 4c, 4d, and 4e respectively show a perspective view of an insert of the second embodiment, a perspective cross sectional view of an outer cap of the second embodiment, and a perspective cross sectional view of the outer cap of fig. 4d with insert of fig. 4c inserted,

figs. 5a and 5b show cross sectional front and side views of a third embodiment of a shield remover in combination with a medical injector,

figs. 5c, 5d, and 5e respectively show a perspective view of an insert of the third embodiment, a perspective cross sectional view of an outer cap of the third embodiment, and a perspective cross sectional view of the outer cap of fig. 5d with insert of fig. 5c inserted, figs. 6a and 6b show cross sectional front and side views of a fourth embodiment of a shield remover in combination with a medical injector,

figs. 6c and 6d respectively show a perspective view of a metal insert of the fourth embodiment, and a perspective cross sectional view of an outer cap of the fourth embodiment with insert of fig. 6c inserted,

figs. 7a and 7b show cross sectional front and side views of a fifth embodiment of a shield remover in combination with a medical injector,

figs. 7c and 7d respectively show a perspective view of an insert of the fifth embodiment, and a perspective cross sectional view of an outer cap of the fifth embodiment,

figs. 7e and 7f respectively show two different perspective cross sectional views of the outer cap of fig. 7d with insert of fig. 7c inserted,

figs. 8a and 8b show cross sectional front and side views of a sixth embodiment of a shield remover in combination with a medical injector,

figs. 8c and 8d respectively show perspective views of an insert and a lock member of the sixth embodiment, and a perspective cross sectional view of an outer cap of the fifth embodiment,

figs. 8e and 8f respectively show two different perspective cross sectional views of the outer cap of the sixth embodiment, and

figs. 8g and 8h respectively show two different perspective cross sectional views of the outer cap of figs. 8e and 8f with the insert shown in fig. 8c and the lock member shown in fig. 8d inserted.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments 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. DESCRIPTION

In the context of the present disclosure it may be convenient to define that the term“distal end” in the appended figures is meant to refer to the end of the injection device which usually carries the injection needle whereas the term“proximal end” is meant to refer to the opposite end of the injection device pointing away from the injection needle. The shown figures are schematical representations for which reason the configuration of the different structures as well as the relative dimensions are intended to serve illustrative purposes only. When the term member, component or element is used for a given component it generally indicates that in the described embodiment the component is a unitary component, however, the same member, component or element may alternatively comprise a number of sub-components just as two or more of the described components could be provided as unitary components, e.g. manufactured as a single injection moulded part. The terms “assembly” and “subassembly” do not imply that the described components necessarily can be assembled to provide a unitary or functional assembly or subassembly during a given assembly procedure but is merely used to describe components grouped together as being functionally more closely related.

With reference to fig. 2 a standard prefilled syringe (PFS) is shown as widely used in industry. Reference is further made to figs. 1a and 1 b which provide cross-sectional side views of an example auto-injector wherein the prefilled syringe is incorporated as part of the auto-injector. The syringe 100 comprises a tubular barrel 1 10 having a neck portion 1 15 located distally wherein the neck portion 1 15 has a reduced diameter compared to the diameter of the barrel 100, thus creating a shoulder portion 160 An injection needle 130 is mounted to the neck portion 1 15 and a removable needle shield assembly 150/155 is provided in the form of a rigid needle shield (RNS) being attached to the neck portion 115 so that the needle shield 120 sealingly and sterilely seals off the needle 130. The needle shield assembly includes a rigid needle shield 150 and a soft cap 155 arranged within the rigid needle shield part 150, the soft cap 155 forming a plug for the injection needle 130 as long as the needle shield assembly 150/155 is mounted onto the neck portion 1 15 of syringe 100. Internally in the barrel 110 a slideably arranged piston 120 is arranged. A drug may be accommodated within the barrel between the piston 120 and the needle 130. Although the shown syringe only incorporates a single piston 120, other configurations may incorporate multiple pistons for accommodation and expelling of one or more drugs, including drugs to be reconstituted before administration. The syringe 100 depicted in fig. 2 further includes a proximally arranged finger flange 117 extending radially from the wall of the barrel 110, wherein the flange includes a couple of alignment features. For the shown syringe, a circumferential gap exists between neck portion 1 15 of barrel 1 10 of the syringe 100 and the syringe needle shield assembly 150/155 covering the needle 130. In the shown embodiment the rigid needle shield part 150 includes four individual axially extending recessed tracks 151 arranged evenly in the circumferentially direction around the outer surface of rigid needle part 150. The distal end of the rigid needle part 150 is terminated by a disc shaped geometry 152 which forms an axial termination of each of the axially extending recessed tracks 151.

The following is a description of an exemplary embodiment of a medical injector for administering a pre-determined amount of a liquid medicament and suitable for use with a needle shield remover in accordance with the invention and in any form thereof. The example device is a disposable spring-driven autoinjector 10 configured for expelling a dose of a drug in a single administration whereafter the device 10 is ready for disposal. However, it is to be noted that the embodiment provides a non-limiting example of an injection device for administering a dose of drug. The invention is equally suitable for use with other types of injection devices, such as manual injectors or electrically controlled motorized injectors, etc.

Referring to figs. 1 a and 1 b, injection device 10 includes an elongated housing 300 that extends along a central longitudinal axis, the housing being configured for being gripped by the palm of the user. The housing 300 forms a tubular shell which is closed off at the proximal end by a cap which in the following will be referred to as a power base 400. During assembly the power base 400 snaps into the housing 300 by means of snap protrusions which are received in recesses or openings to provide a non-releasable mounting of power base 400 within the proximal end of the housing 300.

During storage of auto-injection device 10, at the distal end of the housing 300, a protective outer cap (not shown) will normally be removably arranged to cover and protect a needle arrangement located at the distal end of the housing. The protective outer cap may couple to a rigid needle shield (RNS) so that the RNS is removed together with the protective outer cap. For the auto-injector 10, in the state depicted in figs. 1 a and 1 b, the protective cap and the RNS have already been removed. In the shown embodiment, a syringe holder 800 is arranged to hold syringe 100 inside housing 300 in a manner so that syringe 100 is fixedly withheld within the housing 300 by means of the syringe holder 800. Syringe holder 800 includes a body extending along a central longitudinal axis and being adapted to receive the barrel 1 10 of syringe 100. The body of the syringe holder 800 includes two longitudinal body sections disposed around the central longitudinal axis, where each of the body sections has a distal end with a radial inwards flange section 860 adapted for being received in a circumferential gap between the shoulder section 160 of barrel and the not shown RNS covering the needle. In this way the syringe holder 800 retains the syringe 100 so as to prevent the syringe from moving distally relative to the syringe holder 800. The two longitudinal body sections of syringe holder 800 are connected to each other by means of flexible portions allowing the two body sections to be radially moved away from each other in order to insert the syringe with the RNS attached into syringe holder 800. During manufacture, the assembly formed by the syringe holder and the syringe with the RNS attached is insertable into housing 300 through a proximal opening in the housing shell. Thereafter, the outer cap may be coupled with the RNS and arranged relative to the housing 300.

The lower distal half of the housing 300 includes two opposing window openings 310 allowing visual inspection of the drug contained within the syringe of the device 10. In addition, window openings 310 allow a user of the device to determine whether or not the device 10 has been used for an injection by inspecting the presence or the location of the piston of syringe 100. In the course of an injection, window openings 310 also allow for a rod- shaped plunger 500 of the device to become increasingly visible by the plunger gradually blocking more and more of the space between window openings 310.

In figs. 1 a and 1 b, shown protruding from the distal end of housing 300, is a needle shroud 600 which is received partly within and arranged coaxially and axially slidable relative to housing 300. A needle shroud spring 650 is arranged biasing the needle shroud 600 in the distal direction. Needle shroud 600 is movable, when a proximally directed force is applied to the needle shroud 600, from a first distal extended position (shown in figs. 1a and 1 b) and into a proximal collapsed position (not shown). Upon release of the proximally directed force, the needle shroud spring 650 pushes needle shroud 600 from the proximal collapsed position into a distal extended locked position wherein a not shown lock arrests the needle shroud 600 in a finished protective state. The injection device 10 is configured for being triggered to expel a dose when the needle shroud 600 is moved from the distal extended position towards the proximal collapsed position. As the syringe 100 is substantially fixedly mounted within housing 300 of the device 10, the injection needle 130 follows axial movement of the housing when the housing is moved relative to the needle shroud 600. Piston 120 is driveable towards the needle outlet in order to dispense medicament from the syringe 100. The dispensing is carried out by an expelling assembly incorporating the plunger 500 and a pre-stressed drive spring 550. The needle shroud 600 cooperates with a trigger element 700 which is located at the proximal end of the needle shroud 600 and serves to release the plunger 500 from it’s pre-stressed state.

The expelling assembly of injection device 10 is based on a plunger that is driven in the distal direction along the central longitudinal axis of the device for advancing the piston 120 to thereby expel the dose of drug accommodated within the syringe 100. The plunger 500 in the shown embodiment forms a solid rod having a circular flange arranged at the distal end of the plunger. In device 10 with the rod-shaped plunger 500 arranged along the central axis, a stored energy source in the form of a pre-stressed helical compression drive spring 550 is arranged to encircle the plunger rod 500 along a portion of its length. Drive spring 550 is energized by straining the compression spring during manufacture of the device. The distal end of drive spring 550 is supported onto plunger 500 by a circular flange arranged at the distal end of the plunger. The proximal end of drive spring 550 is supported by a spring seat (non-referenced) formed at a distal end of power base 400 and thus grounds the proximal end of drive spring relative to the housing 300.

As mentioned, in the shown embodiment, the drive spring 550 urges the plunger 500 in the distal direction. In the non-triggered state of the injection device 10, a plunger retaining arrangement associated with the housing engages with a retaining geometry of the plunger to retain the plunger 500 in a pre-firing position. In the shown embodiment, the retaining arrangement comprises, on the plunger 500, a pair of stepped blocking geometries proximally adjoining a recessed portion of the plunger 500. The plunger retaining arrangement further comprises two retaining elements in the form of two retaining arms 410 extending axially in the distal direction from the proximal portion of the power base 400. Each of the two retaining arms 410 forms a radially resilient arm that ends in an enlarged blocking head 415 having its radially inwards facing portion situated in the recessed portion of the plunger rod 500. With the plunger retaining arrangement assuming the state shown in fig. 1a, an inclined proximal surface 415a of enlarged blocking head 415 engages a correspondingly inclined distal surface 515a, these surfaces thus forming retaining geometries of plunger 500. Hence, the force exerted by drive spring 550 acts to push the enlarged blocking heads 415 radially outwards. In the initial non-triggered state of the device 10, as shown in fig. 1a, a radially outward facing surface provided on each of the enlarged blocking heads 415 engages a radially inwards surface of the trigger element 700. The presence of the trigger element 700, when located in the pre-firing position, thus effectively prevents triggering of device 10.

The needle shroud 600 is urged in the distal direction by means of the needle shroud spring 650 so that when no externally applied force is exerted on the needle shroud, the needle shroud assumes its distal extended position which is shown in figs. 1a and 1 b. The needle 130 of syringe 100 is arranged at the distal end of the housing 300, such that the needle shroud 600 completely covers the needle when the needle shroud is in its distal extended position. When an externally applied force is exerted on the needle shroud 600 for moving the needle shroud in the proximal direction relative to the housing, such as when device 10 is pressed with the needle shroud against an injection site, the externally applied force acts counter to the force provided by the needle shroud spring 650 resulting in the needle shroud 600 and the trigger element 700 being forced to move in the proximal direction relative to the housing. When the needle shroud 600 is in its proximal collapsed position, the needle 130 protrudes through a central opening in the needle shroud 600. Upon movement of needle shroud 600 into its proximal collapsed position, the trigger element 700 is pushed proximally as well and the enlarged blocking head 415 of retaining arms 410 are no longer held in their radial inwards position by trigger element 700. On the contrary retaining arms are forced radially outwards by the force emanating from the drive spring 550, the blocking heads thus no longer blocking the plunger 500. As a result the plunger 500 is allowed to plunge distally driven by drive spring 550 causing the entire contents of the syringe 100 to be expelled through the needle 130.

Turning now to figs. 3a through 3e, these drawings show details relating to a needle shield remover assembly according to a first embodiment. Figs. 3a and 3b show cross sectional front and side views of the first embodiment of shield remover assembly in combination with a medical injector wherein only the most distal portion of the medical injector being visible in the drawings. The device shown generally corresponds to the exemplary device shown in figs. 1a and 1 b. Figs. 3a and 3b show an outer cap 350 which couples to the needle shield assembly 150/155 of syringe 100. In the shown embodiment, the outer cap comprises an outer tubular skirt portion 352 generally having radial dimensions to match the outer dimensions of housing 300. At the distal end of outer cap 350, the outer tubular skirt portion 352 ends in a disc shaped end portion 351. A slightly enlarged rim portion at the distal end surface of outer cap 350 forms a gripping surface to ease removal of outer cap 350 from the remainder of the housing 300. The interior of outer cap 350 is generally hollow to accommodate both the distal portion of the needle shroud 600 as well as a distal portion of the needle shield assembly 150/155.

A set of independent intermediary components or inserts 250 serve to couple the outer cap 350 with the needle shield (RNS) 150 (only one insert 250 being visible in fig. 3a). Hence, when outer cap 350 is removed axially from the housing 300, the inserts 250 transfer the removal force exerted onto the outer cap 350 onto the needle shield so that the entire needle shield assembly 150/155 is removed with the outer cap 350.

Fig. 3e shows an assembly formed by the outer cap 350 and the inserts 250 in a state before assembling with the remainder of the medial injector. Fig. 3d shows a corresponding view of outer cap 350 but before inserts 250 having been attached to the outer cap. In the shown embodiment, outer cap 350 includes also an inner tubular portion 353 which extends in the proximal direction away from the disc shaped end portion of outer cap 350. The radially inwards surface of the inner tubular portion 353 extends to a through-going opening emerging at the distal disc shaped end portion 351 of outer cap 350. The radially inwards surface of the inner tubular portion 353 includes a number of axially extending recessed channels 354 each of which is configured to hold one insert 250 in fixed relationship. In the shown embodiment, each of the channels 354 is axially open only at the distal end thereof and thus emerges at the distal end surface of disc shaped end portion 351.

In the shown embodiment, the independent inserts 250, three in total, are fixedly held by the outer cap 350, each insert being retained in a respective channel 354. The inserts are evenly distributed around the circumference of on the inner tubular portion 353. In other embodiments, two, four or more separate inserts may be provided. A detailed perspective view of one insert 250 is depicted in fig. 3c. A proximal portion 250.1 is intended to be positioned oriented with one of its major surfaces arranged facing the central axis of the outer cap and configured to be axially inserted and accommodated in the channel 354 so that a proximal rim edge 250a engages a distally facing axial end face of channel 354. This prevents the insert 250 from being moved further proximally relative to the outer cap 350. Further, pointed protrusions 250c formed along the side portions of the proximal portion 250.1 are adapted to dig into side portions of the channel 354 when the insert has been fully introduced into the channel. This fixedly retains the insert into the channel.

Extending from the distal end of proximal portion 250.1 is a distal portion 250.2 which extends at an angle relative to proximal portion 250.1. When the insert is retained in its channel, the distal portion 250.2 extends distally at an angle so that a free end edge 250b of the distal portion is located closer to the central axis than the proximal portion 250.1. The free end edge 250b is configured to engage and cut slightly into the rigid needle shield 150 of the syringe when a user attempts removing the outer cap 350 from the housing 300. When all three inserts 250 have been arranged in the channels 354, the free end edges 250b are located at the same axial position and radially arranged assuming a circular configuration corresponding to an imaginary circle having a diameter somewhat smaller than the outer dimensions of needle shield 150. The needle shield 150 may exhibit a generally tubular, or slightly tapering conical shape.

The inserts is made of a material having a springing action, such as stainless steel or spring steel. They will typically be fabricated by punching out the inserts from sheet steel to create pointed features 250c and sharp end edges 250b. Instead of sharp end edges 250b, one or more pointed protrusions may be formed along the distal end edge so as to dig into the RNS when the RNS has been coupled with the assembly 250/350.

With the assembly 250/350 formed as indicated in fig. 3e, this assembly may be assembled with the needle shield 150 of the syringe (i.e. the RNS) by introducing the RNS centrally between the end edges 250b of the three inserts 250. Due to the springing action of the inserts 250, the free ends 250b are pressed radially outwards creating a bias for returning the free ends radially inwards towards their original position. Due to the tapering orientation of the distal portion 250.2 a distally directed force being exerted onto the outer cap 350 will be transferred into a radially inwards directed force on the free ends 250b tending to press the free ends into even firmer engagement with the RNS. Figs. 4a through 4e show details relating to a further needle shield remover assembly according to a second embodiment. Compared to the first embodiment, instead of having multiple independent and separate inserts, the second embodiment includes a single insert which is retained in the outer cap 350 due to the shape of the insert 250.

The outer cap 350 of the second embodiment, shown in fig. 4d, generally corresponds to the shape of the outer cap according to the first embodiment. The outer cap 350 of the second embodiment again forms an inner tubular portion 353 which extends in the proximal direction away from the disc shaped distal end portion of outer cap 350. The disc shaped distal end portion in this second embodiment is closed or substantially closed with a transverse wall formed in one piece with the distal disc shaped end portion 351. The said transverse wall and the inner tubular portion 353 forms a receptacle for accommodating and retaining a single intermediary component or insert 250, shown in fig. 4c.

The insert 250 has been manufactured from spring steel by firstly punching out the insert, this time as a single piece, from sheet metal whereafter it is folded along multiple fold lines, all fold lines running generally transverse to the central axis of the outer cap 350. A central transverse portion 250.1 is configured to lay flush against the transverse wall of disc shaped end portion 351 when the folded insert 250 has been inserted into the receptacle of outer cap 350. The insert 250 is inserted from the proximal end of outer cap 250. Two legs connect to and extend at opposing sides from the central transverse portion 250.1. Each leg consists of first, second and third segments that interconnects in series by means of fold lines. A tapering first segment 250.2, slightly angled relative to an axis running parallel with the central axis of the outer cap 350, connects at a first end thereof to the transverse portion 250.1 , At the opposite second end of first segment 250.2 a first end of second segment 250.3 connects. The second segment 250.3 extends substantially parallel with the central axis of the outer cap 350. The opposite second end of segment 250.3 connects to a first end of a third segment 250.4. The third segment forms an angle larger than 90 degrees with respect to the second segment 250.3. Hence, the third segment 250.4 points with its free end edge 250b towards the distal direction, with the third segment 250.4 being slightly angled relative to an axis running parallel to the central axis. In this way the third segment 250.4 of each of the two legs serve the same purpose as the segment 250.2 of the first embodiment discussed above and shown in fig 3c. The receptacle formed by said transverse wall and the inner tubular portion 353 includes retaining recessed channel-formed geometries 354 for holding the folded insert 250 in the correct position. Each of the channel-formed geometries 354 ends in a distally facing end surface 354a which is configured to engage with a folded portion of the respective leg, i.e. at a fold line portion 250a formed between the second segment 250.3 and the third segment 250.4. In this way the insert is prevented from moving proximally relative to the outer cap 350, and the distally facing end surfaces 354a serve to transfer axial forces exerted onto the outer cap 350 during removal from housing 300 onto insert 250, and ultimately towards the RNS 150.

Figs. 5a through 5e show details relating to a further needle shield remover assembly according to a third embodiment. Compared to the second embodiment, instead of having a single insert folded along lines running transverse to the central axis of the outer cap, the insert according to the third embodiment is formed by additional fold lines running generally parallel with central axis of the outer cap 350 so as to create a folded insert configured as a tubular drum-shaped object. Also the third embodiment includes a single insert which is retained in the outer cap 350 due to the shape of the insert 250.

The outer cap 350 of the third embodiment, shown in fig. 5d, generally corresponds to the shape of the outer cap according to the second embodiment. A transverse wall of disc shaped end portion 351 together with an inner tubular portion 353 form a receptacle for accommodating and retaining a single intermediary component or insert 250, shown in fig. 5c.

The insert 250 has been manufactured from spring steel by firstly punching out the insert as a single piece from sheet metal whereafter it is folded along multiple fold lines. A central transverse portion 250.1 is configured to lay flush against the transverse wall of disc shaped end portion 351 when the folded insert 250 has been inserted into the receptacle of outer cap 350. The insert 250 is inserted from the proximal end of outer cap 250. Two legs connect to and extend at opposing sides from central transverse portion 250.1. Each leg comprises a first segment 250.2 which connects at a distal first end of first segment 250.2 to the transverse portion 250.1 and having a second proximal free end. At each of the axially extending side portions of first segment 250.2, by means of axially extending fold lines, a pair of second segments 250.3 connect with the first segment 250.2. In the shown embodiment a further third segment 250.4 connect by an axially extending fold line to each of the second segments 250.3 so that, for each leg, a total of five axially extending segments 250.2,250.3 and 250.4 are formed, with a total of 10 segments configured in a tubular drum configuration.

In the shown embodiment, each of the segments 250.3 and 250.4 ends at the distal end in a barb 250b which has been bent radially inwards so as have the barb pointing distally and radially inwards. In this way the barbs of segments 250.3, 250.4 serve the same purpose as the sharpened edge 250b of the segment 250.4 of the second embodiment discussed above and shown in fig 4c.

The receptacle formed by said transverse wall and the inner tubular portion 353 includes retaining recessed geometries 354 for holding the folded insert 250 in the correct position. Each of the recessed geometries 354 ends in a distally facing end surface 354a which is configured to engage with a proximal end portion 250a of the segments 250.3 and 250.4 of the respective leg. In this way the insert is prevented from moving proximally relative to the outer cap 350, and the distally facing end surfaces 354a serve to transfer axial forces exerted onto the outer cap 350 during removal from housing 300 onto insert 250, and ultimately towards the RNS 150.

Figs. 6a through 6d show details relating to a further needle shield remover assembly according to a fourth embodiment. Also the fourth embodiment includes an intermediary component in the form of a single insert 250 which is retained in the outer cap 350 due to the shape of the insert 250.

The outer cap 350 of the fourth embodiment, shown in fig. 6d, generally corresponds to the shape of the outer cap according to the first embodiment. The outer cap 350 includes an inner tubular portion 353 which extends in the proximal direction away from the distal disc shaped end portion 351 of outer cap 350. The radially inwards facing surface of the inner tubular portion 353 extends to a through-going opening emerging at the distal disc shaped end portion 351 of outer cap 350. A round-going rim extends inwardly from the radially inwards surface at the most proximal portion of the inner tubular portion 353. A proximal facing surface 354a of the round-going rim serves to hold the insert, shown in fig. 6c, in fixed relationship when the insert 250 has been inserted into the inner tubular portion 353. During assembly, the insert 250 is inserted from the distal side of outer cap 350 through the through- going opening until the edge 250a engages the round-going rim. A separate tool may be used to hold the insert 250 at its proper location when the RNS is inserted and coupled to the insert 250.

Referring to fig. 6c, the insert 250 according to the fourth embodiment is provided as a frusto- conical member formed from a metal, the insert 250 having a large diameter portion 250a arranged at the proximal portion thereof and a small diameter portion 250b arranged at the distal portion thereof. A slit 255 cuts open the frusto-conical member so that the frusto- conical member is able to radially expand when the RNS of a syringe is inserted through the insert 250. The small diameter portion 250b is configured with a slightly smaller diameter than the outer dimension of the RNS. However, due to the slit 255, the frusto-conical member is able to expand to accommodate the RNS. As the material portions of the small diameter portion arranged at the distal end of insert 250 is oriented with an angle with respect to the central axis of the outer cap, the frusto-conical member is able to contract when the insert 250 exerts a distally directed force on the RNS 150 during removal of the outer cap 350 from the housing 300. The inner distal edge 250b of the frusto-conical member is preferably sharpened so as to make the insert cut slightly into the outer surface of the RNS 150 when the outer cap 350 is removed from the housing 300.

Figs. 7a through 7f show details relating to a further needle shield remover assembly according to a fifth embodiment. Also the fifth embodiment includes an intermediary component in the form of a single insert 250, however made from a polymer material. Also the outer cap 350 is made from a polymer material.

Fig 7c provides a perspective view of the insert 250 which is provided as a generally tubular shaped hollow member. A large diameter proximal base portion includes two opposed radially resilient gripping arms 254 with gripping heads 254b configured for snapping engagement with an engagement geometry 151 , 152 of the needle shield 150 when the needle shield, i.e. the RNS, has been introduced into the base portion of insert 250. A reduced diameter portion 251 connects at a distal portion of the base portion. In the shown embodiment, two islands of additional material 252 protrudes radially outwards from the reduced diameter portion 251 located on opposite sides of the reduced diameter portion, e.g. at locations close to the most distal end portion of insert 250.

The outer cap 350 of the fifth embodiment, shown in fig. 7d, generally corresponds to the shape of the outer cap according to the first embodiment. The outer cap 350 includes an inner tubular portion 353 which extends in the proximal direction away from the distal disc shaped end portion 351 of outer cap 350. The radially inwards facing surface of the inner tubular portion 353 extends to a through-going opening emerging at the distal disc shaped end portion 351 of outer cap 350. The insert 250 is to be located within the inner tubular portion 353 with the axial position in accordance with the particular axial dimensions of the syringe and RNS in question, i.e. it will to a large degree be dependent on wide tolerances. The material islands 252 on insert 250 may be formed to have a radial outer dimension which closely matches the inner diameter of the inner tubular portion.

In the fifth embodiment, the syringe 100 with the RNS 150 is assembled together with the insert 250 so that the gripping heads 254 snaps into the recessed tracks 151 and locks behind the disc shaped geometry 152 of RNS 150. In alternative embodiments, the gripping heads 254 may alternatively be configured to grip behind a proximal end of the RNS, at the location where a gap is typically formed between the RNS and the shoulder portion of the barrel of a syringe.

After the sub-assembly formed by the syringe with RNS and the insert 250 has been provided, and typically also including the housing of a medical injector into the sub-assembly, the outer cap 350 is mounted onto the insert 250 with the outer cap being positioned at the desired target position. In this state, the outer cap is still freely slideable relative to the RNS and forces tending to move the RNS relative to the syringe may be avoided.

As a final step in assembling the syringe RNS with the outer cap 350, the insert 250 is bonded to the outer cap 350 in a material bond, in the shown fifth embodiment by using laser radiation to melt the material islands 252 and join the material with the surrounding material located at the inner tubular portion 353 of outer cap 350. Referring to fig. 7b, the laser welding operation causes two opposed laser welding portions 260 to be made. It is to be noted that other alternative joining methods may be used as well, such as ultrasonic welding or gluing.

Finally, a sixth embodiment of a needle shield remover will now be described making reference to figs. 8a through 8h. The sixth embodiment has many details in common with the fifth embodiment described above. However, instead of using a laser welding operation for joining and fastening the insert with the outer cap, in the sixth embodiment, an additional lock member is used for arresting the outer cap relative to the insert. Fig 8c provides a perspective view of the insert 250 which, again, is made from a polymer material, and which is provided as a generally tubular shaped hollow member. A large diameter proximal base portion includes two opposed radially resilient gripping arms 254 with gripping heads 254b configured for snapping engagement with engagement geometry 151 , 152 of the needle shield 150 when the needle shield, i.e. the RNS, has been introduced into the base portion of insert 250. A reduced diameter portion 251 connects at a distal portion of the base portion. In the shown embodiment, a series of axially disposed detents 257 are formed on the radially outwards facing surface of the reduced diameter portion 251 at a location close to the most distal end portion of insert 250, each of the detents is formed as a circumferential groove arranged between neighboring circumferential protrusions.

Fig. 8d show a perspective view of the additional lock member 280 referred to above. The lock member forms a plug which is insertable from a non-locked first position and into a locked second position. The lock member 280 includes a distal end wall 281 and two opposed legs 285 each protruding in the proximal direction away from the distal end wall 281. Each of the opposed legs 285 defines a blocking geometry which will be described below.

The outer cap 350 of the sixth embodiment, shown in figs. 8e and 8f generally corresponds to the shape of the outer cap according to the fifth embodiment. The outer cap 350 includes an inner tubular portion 353 which extends in the proximal direction away from the distal disc shaped end portion 351 of outer cap 350. The radially inwards facing surface of the inner tubular portion 353 extends to a through-going opening or aperture emerging at the distal disc shaped end portion 351 of outer cap 350. The insert 250 is to be located within the inner tubular portion 353 with the axial position in accordance with the particular axial dimensions of the syringe and RNS in question, i.e. it will to a large degree be dependent on wide tolerances.

In the shown embodiment, a retaining protrusion 357 is formed on a longitudinally extending resilient arm 356, the longitudinally extending arm being radially movable when the lock member assumes the first position. The retaining protrusion 357 protrudes radially inwards from the resilient arm 356 so that it may selectively engage with any one of the series of axially disposed detents 257 provided on the insert 250. The retaining protrusion 357 of the resilient arm 356 is selectively moveable in and out of engagement with any of the a series of axially disposed detents 257 provided on insert 250. The through-going opening in the outer cap 350 is formed so that it mates with the distal end wall 281 of the lock member 280 so that distal end wall 281 is received in the opening when the lock member assumes the second position. Further the two opposed legs 285 of lock member 280 is insertable into the outer cap 350 in a manner wherein the blocking geometry of each leg 285 will squeeze in and support the resilient arm 257 on the radial outwards side thereof. When the lock member assumes the second position, the blocking geometry will support the resilient arm 356 and bias the arm radially inwards to arrest the resilient arm with its retaining protrusion 357 in locking engagement with the selectively engaged one of the series of axially disposed detents 257.

In the sixth embodiment, the syringe 100 with the RNS 150 is assembled together with the insert 250 so that the gripping heads 254b snaps into the recessed tracks 151 and locks behind the disc shaped geometry 152 of RNS 150. In alternative embodiments, the gripping heads 254b may alternatively be configured to grip behind a proximal end of the RNS, at the location where a gap is typically formed between the RNS and the shoulder portion of the barrel of a syringe.

After the sub-assembly formed by the syringe with RNS and the insert 250 has been provided, and typically also including the housing of a medical injector into the sub-assembly, the outer cap 350 is mounted onto the insert 250 with the outer cap being positioned at the desired target position. In this state, the outer cap is still freely slideable relative to the RNS and forces tending to move the RNS relative to the syringe may to a large degree be avoided. After the outer cap 350 has been moved to the desired position relative to the insert 250, the lock member is moved to its locked second position where the protrusion of the flexible arm 356 has been moved into engagement with a selected one of the series of axially disposed detents. With the locking member 280 assuming the second position the locking member is permanently arrested by means of a snap protrusion 286 which cooperates with a snap engagement geometry on the outer cap 350. An effective retaining mechanism has thus been provided between the insert 250 and the outer cap 350.

With the proposed solutions according to the embodiments disclosed herein a number of inexpensive solutions have been proposed, each of which provides for a reliable coupling between the outer cap and the RNS of a held syringe. The disclosed solutions provide superior manufacturability for enabling low-cost manufacturing and assembly in an automatic assembly line.

Claims

1. A shield remover for removing a needle shield (150/155) from a syringe (100), comprising: an outer cap (350) comprising a tubular skirt member (352) arranged along a central axis for enclosing the needle shield (150/155) coupled to the syringe (100), an intermediary component (250) coupled between the outer cap (350) and the needle shield (150/155), the intermediary component (250) comprising a shield engagement grip means (254) for coupling the intermediary component (250) with the needle shield (150/155) so that when the shield remover is pulled away from the syringe (100), the intermediary component (250) exerts force against the needle shield (150/155) to remove the needle shield (150/155) from the syringe (100), and a lock member (280), wherein the outer cap (350) and the intermediary component (250) comprises at least one pair of engaging mechanisms, each pair of engaging mechanisms comprising a series of axially disposed detents (257) formed on one of the outer cap (350) and the intermediary component (250), and a retaining protrusion (357) formed on the other of the outer cap (350) and the intermediary component (250), wherein the retaining protrusion (357) and the series of axially disposed detents (257) are configured for resiliently moving into engagement with each other so that said retaining protrusion (357) selectively engages one of said series of axially disposed detents (257), and

wherein the lock member (280) is configured for being received by the outer cap (350) and movable between a first position and a second position, wherein the lock member (280) in the first position allows said resilient moving into engagement of the retaining protrusion (357) and the series of axially disposed detents (257), and wherein the lock member (280) in the second position cooperates with the outer cap (350) and/or the intermediary component (250) to maintain locking engagement between the retaining protrusion (357) and the selectively engaged one of the series of axially disposed detents (257).

2. A shield remover as defined in claim 1 , wherein said resiliently moving into engagement includes a radial movement towards or away from said central axis.

3. A shield remover as defined in claim 2, wherein, for each pair of engaging mechanisms, one of the retaining protrusion (357) and the series of axially disposed detents (257) is formed on a longitudinally extending resilient arm (356), the longitudinally extending resilient arm being radially movable when the lock member (280) assumes the first position.

4. A shield remover as defined in claim 3, wherein the longitudinally extending resilient arm (356) is formed by the outer cap (350).

5. A shield remover as defined in claim 3, wherein the longitudinally extending resilient arm (356) is formed by the intermediary component (250).

6. A shield remover as defined in any of the claims 3-5, wherein the lock member (280) includes a blocking geometry (285) for each pair of engaging mechanisms, said blocking geometry (285) engaging a respective one of the longitudinally extending resilient arms (356) when the lock member (280) assumes the second position to maintain locking engagement between the retaining protrusion (357) and the selected one of the series of axially disposed detents (257).

7. A shield remover as defined in any of the claims 3-6, wherein the outer cap (350) defines a distal end surface (351 ) and an outer circumferential skirt (352) extending proximally from the distal end surface (351 ), and wherein respective ones of said longitudinally extending resilient arms (356) connects to the distal end surface radially inwards from the outer circumferential skirt (352).

8. A shield remover as defined in claim 7, wherein the distal end surface (351 ) includes at least one aperture configured to allow the lock member (280) to be inserted in proximal direction through the aperture.

9. A shield remover as defined in claim 8, wherein the lock member (280) includes a distal end face (281 ), and wherein the distal end face (281 ) of the lock member (280) lies flush with the distal end face (351 ) of the outer cap (350) when the lock member (280) assumes the second position.

10. A shield remover as defined in any of the claims 1-9, wherein the lock member (280) comprises a colour coding which represents the type or kind of drug accommodated in the syringe (100).

11. A shield remover as defined in any of the claims 1-10, wherein the shield engagement grip means comprises at least one radially flexible grip member (254) defined by the intermediary component (250), the radially flexible grip member (254) being configured for snapping engagement with an engagement geometry (151 ) of the needle shield (150/155).

12. A medical injector (10) comprising a shield remover as defined in any of the claims 1-1 1 , and a syringe (100) having a needle shield (150/155) attached.

13. A medical injector (10) as defined in claim 12, wherein the needle shield (150/155) defines a radially outwards facing surface comprising one or more radial apertures (151 ), and wherein the shield engagement mechanism includes at least one grip member (254) each locking into a respective one of said one or more radial apertures.

14. A medical injector (10) as defined in any of the claims 12-13, wherein the medical injector comprises a housing wherein a wave shaped interface is provided between the housing and the outer cap (350), the wave shaped interface configured to axially move and separate the outer cap (350) from the housing as the outer cap (350) is twisted relative to the housing.