Disposable injection pen

Abstract

The present invention provides a disposable injection pen, comprising an upper pen housing assembly and a lower pen housing assembly that are assembled and matched. The lower pen housing assembly includes a pen cap, a protective shell that is clamped into the pen cap, and a bracket that supports a prefilled syringe arranged on the inner circumference of the protective shell. The pen cap is provided with a pen cap spring that extends toward the bracket and presses against the axial edge of the needle guard. The lower pen housing assembly is supported by the protective shell installed in the pen cap, and the prefilled syringe can be fixed in the bracket. The pen cap is provided with a pen cap spring that presses against the axial edge of the needle guard. By providing a pen cap with a spring structure, the spring is pressed against the circumferential edge of the needle guard, so that the needle guard is subjected to an axial withdrawal force. The clamping structure is stable, ensuring smooth withdrawal of the needle guard.

Description

Technical Field

[0001] The present invention relates to the technical field of injection pens, and more particularly to a disposable injection pen. Background Art

[0002] A disposable injection pen is a pen-shaped syringe that comes pre-filled with medication, also known as a prefilled injection pen. In an existing disposable autoinjector pen structure, the disposable autoinjector pen contains an injector assembly consisting of a pre-filled syringe, pre-filled liquid, and a rubber stopper.

[0003] To use, first remove the pen cap, which removes the needle guard from the prefilled syringe. Then, press the protective case to initiate a subcutaneous injection. The injection is powered by a compression spring, and the injection process is visible. A window is located near the needle tip in the protective case, and a tone indicates completion when the injection is nearing completion, alerting the user. Stop pressing the protective case, and the spring's reaction force returns the case to its pre-use position, locking it in place. Pressing the protective case again prevents the needle tip from being exposed, preventing the needle from extending after use and preventing injuries.

[0004] In the prior art, the needle guard is removed by either installing a separate cylindrical metal piece with a barbed structure extending from its inner ring, which squeezes the needle guard through the barbs. The metal piece is then connected to the pen cap, allowing the needle guard to be removed by pulling the pen cap out. Alternatively, the injection pen cap is equipped with two or more elastic arms with inwardly pointing hooks at their protruding ends. The hooks interact with the needle guard through a step or groove structure, allowing the needle guard to be removed when the pen cap is pulled out. The aforementioned horizontal clip-on mounting method is prone to clip-on failure, making the needle guard difficult to remove.

[0005] Furthermore, existing disposable injection pens are not compatible with high-viscosity solutions, limiting their versatility. Furthermore, the unclear sound signaling the injection is complete affects the user experience. Existing disposable injection pens feature a safety lock to prevent misuse. However, since the safety lock does not indicate activation, users cannot verify that the safety lock has been activated without first pressing the lock. Summary of the Invention

[0006] In view of this, the present invention provides a disposable injection pen to ensure smooth removal of the needle guard cap.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A disposable injection pen comprises an upper pen housing assembly and a lower pen housing assembly that are assembled together. The lower pen housing assembly comprises a pen cap and a protective shell that is clamped in the pen cap. The inner ring of the protective shell is provided with a bracket for supporting a prefilled syringe.

[0009] The pen cap is provided with a pen cap spring extending toward the bracket, and the pen cap spring is pressed and fitted against the axial edge of the needle guard cap.

[0010] Preferably, in the disposable injection pen, the pen cap spring has a first hanging portion fixed to the pen cap and a second hanging portion extending toward the bracket;

[0011] The second hanging portion includes two compression spring wires overlapped on the radial ends of the needle guard cap.

[0012] Preferably, in the above disposable injection pen, the pen cap comprises a pen cap outer ring and a pen cap inner ring which are coaxially arranged, and the protective shell is clamped between the pen cap outer ring and the pen cap inner ring.

[0013] Preferably, in the above-mentioned disposable injection pen, the inner ring of the pen cap is provided with a pen cap ear protruding radially outward, and the pen cap spring has a first hanging portion that is snap-fitted with the pen cap ear, and a second hanging portion that is press-fitted with the needle guard cap.

[0014] Preferably, in the above-mentioned disposable injection pen, the first hanging portion includes a first hanging hook portion that is engaged with the pen cap ear portion, and a vertical bending portion connected to the first hanging hook portion and extending toward the bracket, and the second hanging portion is connected to the vertical bending portion.

[0015] Preferably, in the above-mentioned disposable injection pen, the first hanging hook portion, the vertically bent portion and the second hanging portion are a pen cap spring structure formed by bending a spring wire;

[0016] The pen cap spring structure comprises two spring wire bending structures arranged in parallel.

[0017] Preferably, in the disposable injection pen, the pen cap ears include two arranged at radial ends of the pen cap inner tube, and the first hanging hook includes a group of the first hanging hooks respectively hung on the two pen cap ears;

[0018] The second hanging portion includes two compression spring wires spanning between the two pen cap ears.

[0019] Preferably, in the above-mentioned disposable injection pen, a spring limiting portion cooperating with the pen cap spring hanging is provided in the pen cap ear, and the spring limiting portion includes a horizontal limiting portion clamped with the first hanging hook portion, and a vertical limiting portion separating the spring wires arranged in parallel.

[0020] Preferably, in the above-mentioned disposable injection pen, the two compression spring wires are straight compression spring wires or arc-shaped compression spring wires.

[0021] Preferably, in the above-mentioned disposable injection pen, the bracket includes a bracket tube portion for lifting and supporting the bottle body of the prefilled syringe, and a first arm plate and a second arm plate extending from the bracket tube portion, and the first arm plate and the second arm plate are pressed against the radial sides of the needle guard cap.

[0022] Preferably, in the disposable injection pen, the bracket tube is provided with two lifting protrusions for lifting the bottle body, and the first arm plate and the second arm plate are respectively connected to the two lifting protrusions;

[0023] The roots of the first arm plate and the second arm plate are respectively provided with bracket grooves for accommodating the expansion of the two compression spring wires.

[0024] Preferably, the above-mentioned disposable injection pen further includes a lower pen shell mounted on the outer ring of the protective shell, the lower pen shell having a coaxially arranged lower pen shell outer cylinder and a lower pen shell inner cylinder, and the inner wall of the lower pen shell inner cylinder is provided with a position corresponding to the vertical bending portion, which pushes the two compression spring wires to open into the bracket groove and contracts after the prefilled syringe is assembled into place, so that the compression spring wire overlaps the lower pen shell protrusion at the edge of the needle guard cap shaft end.

[0025] Preferably, in the above-mentioned disposable injection pen, a fixed sleeve is provided in the upper pen housing assembly, and a rotating slider arranged to slide along the axial direction is provided on the fixed sleeve;

[0026] The fixed sleeve guides the axial sliding of the rotary slider, and when the rotary slider slides axially to the unlocking position, drives the rotary slider to rotate so as to collide with the fixed sleeve to emit an unlocking prompt sound.

[0027] Preferably, in the above-mentioned disposable injection pen, a fixing sleeve groove is provided on the outer wall surface of the fixing sleeve, and a rotating slider protrusion extends from the inner wall surface of the rotating slider;

[0028] The fixed sleeve groove includes a fixed sleeve sliding groove for guiding the axial sliding of the rotary slider protrusion, and an impact step for impact cooperation with the rotary slider.

[0029] Preferably, in the disposable injection pen, the fixed sleeve is provided with a first torsion and compression spring, and the first torsion and compression spring is connected to the rotating slider;

[0030] The first torsion spring provides axial elastic support to the rotary slider and drives the rotary slider to perform circumferential torsion.

[0031] Preferably, in the above-mentioned disposable injection pen, the impact step is a first step and a second step arranged in the groove of the fixed sleeve and arranged along the torsion direction of the first torsion spring, and the first step and the second step are arranged sequentially along the extension direction of the first torsion spring.

[0032] Preferably, in the disposable injection pen described above, the impact steps are both located on the first step and the second step and are step side walls opposite to the twisting direction of the protrusion of the rotary slider.

[0033] Preferably, in the above-mentioned disposable injection pen, the fixed sleeve slot has a first fixed sleeve notch connected to the first step; and a second fixed sleeve notch is provided between the first step and the second step to guide the first torsion spring to rotate from the first step into the second step.

[0034] Preferably, in the above-mentioned disposable injection pen, the rotary slider is a cylindrical structured rotary slider, and the rotary slider is sleeved on the fixed sleeve.

[0035] Preferably, the disposable injection pen further comprises a sleeve on the fixed sleeve, and a directional sleeve driving the rotating slider to slide axially.

[0036] Preferably, in the above disposable injection pen, protective fins extend from the protective shell and abut against the fixed sleeve to push the fixed sleeve to move.

[0037] Preferably, in the above-mentioned disposable injection pen, a rotating sleeve for driving the screw to perform the injection action is further provided in the upper pen housing assembly;

[0038] The upper pen housing assembly is further provided with a sounding member that rotates synchronously with the rotating sleeve;

[0039] At the end of the injection operation, the sounding member rotates circumferentially and collides with the rotating sleeve to emit an injection completion prompt sound.

[0040] Preferably, in the above-mentioned disposable injection pen, a synchronously rotating drive cover is arranged at the protruding end of the screw of the rotating sleeve, an annular inner cavity is formed between the rotating sleeve and the drive cover, and the sounding member is arranged in the annular inner cavity.

[0041] Preferably, in the above-mentioned disposable injection pen, the screw can be arranged in the rotating sleeve in a spirally advancing manner, and the tail of the screw is provided with a driving structure for driving the sounding member to rotate synchronously.

[0042] Preferably, in the disposable injection pen, a torsion and compression spring is arranged in the drive cap to provide rotational torsion and axial pressure to the sounding member;

[0043] The end of the screw rod is provided with a driving inner cylinder, the first end of the torsion and compression spring is connected to the driving cover, and the second end of the torsion and compression spring is connected to the sounding member;

[0044] The torsion compression spring presses the sounding member tightly into the driving inner tube.

[0045] Preferably, in the above-mentioned disposable injection pen, the annular inner cavity is arranged between the annular inner ring and the annular outer ring of the drive cover, and the torsion spring is sleeved on the annular inner ring;

[0046] The annular inner ring and the driving inner cylinder are provided with an axial sliding gap, and the inner ring of the sounding member is provided with an inner protrusion of the sounding member extending into the sliding gap.

[0047] Preferably, in the disposable injection pen described above, the tail of the screw is provided with an axially arranged long strip protrusion, and the circumferential end surface of the long strip protrusion abuts against the inner protrusion of the sounding member to drive the sounding member to rotate.

[0048] Preferably, in the above-mentioned disposable injection pen, the inner convex points of the sound member are provided as a plurality arranged along the circumference of the inner ring, and a driving gap for the elongated protrusion to pass through is formed between adjacent inner convex points of the sound member.

[0049] Preferably, in the above-mentioned disposable injection pen, a first groove is provided on the inner wall surface of the driving inner tube, and the first groove has a guiding inclined surface extending from the root of the driving inner tube to the tube mouth;

[0050] A second groove is further provided on the inner wall surface of the driving inner cylinder. The second groove has an impact side surface away from the guide inclined surface. A side of the second groove close to the guide inclined surface forms an impact notch connecting the first groove and the second groove.

[0051] An outer sound convex point extends out from the outer wall surface of the sound piece, and the outer sound convex point is pressed tightly against the guide inclined surface.

[0052] Preferably, in the above-mentioned disposable injection pen, the sound outer protrusions include two radially extending from both ends of the outer wall surface, and the first groove and the second groove include two groups arranged in the radial direction of the driving inner cylinder.

[0053] Preferably, in the above-mentioned disposable injection pen, a rotating sleeve for driving the screw to perform the injection action is provided in the upper pen housing assembly;

[0054] The upper pen housing assembly is further provided with a sounding member that rotates synchronously with the rotating sleeve;

[0055] At the end of the injection operation, the sounding member slides axially and rotates to collide with the rotating sleeve to emit an injection completion prompt sound.

[0056] Preferably, in the above-mentioned disposable injection pen, a synchronously rotating drive cover is arranged at the protruding end of the screw of the rotating sleeve, an annular inner cavity is formed between the rotating sleeve and the drive cover, and the sounding member is arranged in the annular inner cavity.

[0057] Preferably, in the above-mentioned disposable injection pen, the screw can be arranged in the rotating sleeve in a spirally advancing manner, and the tail of the screw is provided with a driving structure for driving the sounding member to rotate synchronously.

[0058] Preferably, in the disposable injection pen, a compression spring is arranged in the drive cap to provide rotational torsion and axial pressure to the sounding member;

[0059] The end of the screw rod is provided with a driving inner cylinder, the first end of the compression spring is connected to the driving cover, and the second end of the compression spring is connected to the sounding member;

[0060] The compression spring presses the sounding member tightly into the driving inner tube.

[0061] Preferably, in the above-mentioned disposable injection pen, the annular inner cavity is arranged between the annular inner ring and the annular outer ring of the drive cover, and the compression spring is sleeved on the annular inner ring;

[0062] The annular inner ring and the driving inner cylinder are provided with an axial sliding gap, and the inner ring of the sounding member is provided with an inner protrusion of the sounding member extending into the sliding gap.

[0063] Preferably, in the above-mentioned disposable injection pen, the tail of the screw is provided with an axially arranged long strip protrusion, and the axial end of the long strip protrusion is abutted against the inner protrusion of the sound piece, so that the sound piece slides axially.

[0064] Preferably, in the above-mentioned disposable injection pen, the inner wall surface of the driving inner cylinder is provided with an axially arranged guide protrusion, and the outer wall surface of the sounding member is provided with a sliding groove that slides with the guide protrusion.

[0065] Preferably, in the above disposable injection pen, the guide boss and the sliding groove include two groups respectively arranged at two radial ends of the driving inner cylinder.

[0066] Preferably, in the disposable injection pen described above, a head protrusion is provided on the head of the sounding member, and a drive cover protrusion is provided on the inner ring of the drive cover, and the head protrusion and the drive cover protrusion collide and fit at the same radial position.

[0067] The disposable injection pen provided by the present invention comprises an upper pen housing assembly and a lower pen housing assembly that are assembled and matched. The lower pen housing assembly comprises a pen cap, a protective shell that is clamped into the pen cap, and a bracket that supports a prefilled syringe arranged on the inner ring of the protective shell. The pen cap is provided with a pen cap spring that extends toward the bracket and presses against the axial edge of the needle guard. The lower pen housing assembly is supported by the protective shell installed in the pen cap, and the prefilled syringe can be fixed in the bracket. The pen cap is provided with a pen cap spring that presses against the axial edge of the needle guard via the pen cap spring. By providing a pen cap with a spring structure, the spring is pressed against the circumferential edge of the needle guard, so that the needle guard is subjected to an axial withdrawal force, and the clamping structure is stable, ensuring smooth withdrawal of the needle guard. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0069] Figure 1 An exploded view of the first structure of the disposable injection pen provided in this application;

[0070] Figure 2 An exploded view of the second structure of the disposable injection pen provided in this application;

[0071] Figure 3 A schematic diagram of the structure of the pen cap in the disposable injection pen provided in this application;

[0072] Figure 4 A schematic diagram of the structure of the pen cap spring in the disposable injection pen provided in this application;

[0073] Figure 5 It is a cross-sectional view of the installation structure of the pen cap and the pen cap spring;

[0074] Figure 6 Schematic diagram of the structure of the protective shell;

[0075] Figure 7 is a structural diagram of the bracket;

[0076] Figure 8 This is a schematic diagram of the structure after the lower pen housing assembly is loaded into the prefilled syringe;

[0077] Figure 9 Schematic diagram of the structure of the pen shell;

[0078] Figure 10 This is a cross-sectional view of the internal structure of the lower pen shell;

[0079] Figure 11 Schematic diagram of the assembly structure of the upper pen housing and the lower pen housing;

[0080] Figure 12 This is a cross-sectional view of the internal structure of the upper pen housing assembly;

[0081] Figure 13 Schematic diagram of the internal structure of the upper pen housing assembly;

[0082] Figure 14 A cross-sectional view of the directional slider structure of the upper pen housing assembly;

[0083] Figure 15 Schematic diagram of the fixed sleeve structure in the upper pen housing assembly;

[0084] Figure 16 Schematic diagram of the rotary slider structure of the upper pen housing assembly;

[0085] Figure 17 Schematic diagram of the screw drive structure in the upper pen housing assembly;

[0086] Figure 18 A schematic diagram of the first sound generating structure provided in this application;

[0087] Figure 19 for Figure 18 Schematic diagram of the rotating sleeve structure;

[0088] Figure 20 for Figure 18 Schematic diagram of the middle sounding member in the first direction;

[0089] Figure 21 for Figure 18 Schematic diagram of the middle sound element in the second direction;

[0090] Figure 22 A schematic diagram of the second sound generating structure provided in this application;

[0091] Figure 23 for Figure 22 Schematic diagram of the rotating sleeve structure;

[0092] Figure 24 for Figure 22 Schematic diagram of the middle sounding member in the first direction;

[0093] Figure 25 for Figure 22 Schematic diagram of the second direction of the middle sound component. DETAILED DESCRIPTION

[0094] The invention discloses a disposable injection pen, which ensures that the needle protection cap can be smoothly pulled out.

[0095] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0096] like Figure 1-Figure 5 As shown, Figure 1 An exploded view of the first structure of the disposable injection pen provided in this application; Figure 2 An exploded view of the second structure of the disposable injection pen provided in this application; Figure 3 A schematic diagram of the structure of the pen cap in the disposable injection pen provided in this application; Figure 4 A schematic diagram of the structure of the pen cap spring in the disposable injection pen provided in this application; Figure 5 This is a cross-sectional view of the installation structure of the pen cap and pen cap spring.

[0097] The present application provides a disposable injection pen, comprising an upper pen housing assembly and a lower pen housing assembly that are assembled and matched. The lower pen housing assembly includes a pen cap, a protective shell that is mounted within the pen cap, and an inner ring of the protective shell that supports a prefilled syringe. The pen cap is provided with a pen cap spring that extends toward the bracket and presses against the axial edge of the needle guard. The lower pen housing assembly is supported by the protective shell mounted within the pen cap, and the prefilled syringe can be fixed within the bracket. The pen cap is provided with a pen cap spring that presses against the axial edge of the needle guard. By providing a pen cap with a spring structure, the spring is pressed against the circumferential edge of the needle guard, so that the needle guard is subjected to an axial withdrawal force. The mounting structure is stable, ensuring smooth withdrawal of the needle guard.

[0098] The disposable injection pen provided in the present application includes an upper pen housing assembly and a lower pen housing assembly that are assembled together. The lower pen housing assembly is used to arrange a prefilled syringe 006, and the upper pen housing assembly is used to arrange a driving device that drives the prefilled syringe 006 to perform injection.

[0099] The lower pen housing assembly includes a pen cap 001 and a protective housing 003 that snaps onto the inner ring of pen cap 001. The outer ring of protective housing 003 further houses a lower pen housing 004, the first end of which is also mounted within the pen cap. The inner ring of protective housing 003 further houses a bracket 005, which snaps into place with protective housing 003. A prefilled syringe 006 is mounted within bracket 005. The needle guard 601 of the prefilled syringe 006 extends into the pen cap 001 and is pressed against the axial edge of the needle guard 601 by a cap spring 002 mounted on the pen cap 001, allowing the needle guard 601 to be removed simultaneously with the removal of the pen cap 001.

[0100] Specifically, the pen cap 001 has a double-layer structure, including an outer ring 101 and an inner ring 102 coaxially arranged with the outer ring 101 . An annular channel is formed between the outer ring 101 and the inner ring 102 for inserting and installing the protective shell 003 .

[0101] A group of snap-fitting spring pieces 103 are provided on the first side radially opposite to the inner ring 102 of the pen cap. The root of the inner ring 102 of the pen cap where the snap-fitting spring pieces 103 are located is set as an open hole structure. The snap-fitting spring pieces 103 extend axially along the inner ring 102 of the pen cap and can produce a swinging deformation in the radial direction. The outer side surface of the snap-fitting spring pieces 103 has protruding snap-fitting teeth 104. Correspondingly, the inner end surface of the insertion end of the protective shell 003 is provided with a snap-fitting groove corresponding to the snap-fitting teeth 104, so that the protective shell 003 can be inserted into the annular gap between the inner ring 102 of the pen cap and the outer ring 101 of the pen cap to achieve snap-fitting positioning.

[0102] Furthermore, the outer peripheral surface of the inner ring 102 of the pen cap is protrudingly arranged with a plurality of axially extending external support ribs 105, and the inner wall surface of the outer ring 101 of the pen cap is protrudingly arranged with a plurality of axially arranged internal support ribs 106. The internal support ribs 106 and the external support ribs 105 are used to tighten the loading end of the protective shell 003, further ensuring the stability of the assembly structure between the protective shell 003 and the pen cap 001.

[0103] A group of outwardly extending pen cap ears 107 are provided on the second side radially opposite to the pen cap inner ring 102. The pen cap ears 107 are guide bosses in the shape of spline teeth extending axially. The guide bosses are located on the side of the root of the pen cap inner ring 102 and have a thin-walled structure. A spring limit portion 108 is provided on the side of the guide bosses located on the protruding end of the pen cap inner ring 102.

[0104] In this embodiment, the cap inner ring 102 is a hollow cylindrical structure, integrally connected at its base to the base of the cap outer ring 101 via an annular bottom wall. This hollow cylindrical design allows for injection molding of the cap 001. The spring clip 103 and the opening structure, as well as the thin-walled guide boss structure 109, are directly molded at the base of the cap inner ring 102. Support ribs are injection molded between the inner and outer rings 102, 101.

[0105] The spring stopper 108 includes a transverse stopper 118 and a vertical stopper 128. The transverse stopper 118 is arranged on the inner wall surface of the guide boss along the circumference of the guide boss. The vertical stopper 128 is arranged in the middle of the transverse stopper 118 and extends toward the axial end of the guide boss. The axial end of the guide boss is connected to two laterally spaced positioning grooves through the vertical stopper 128. The transverse stopper 118 protrudes from the inner wall surface of the guide boss, forming a positioning step between the transverse stopper 118 and the thin-walled structure 109 of the guide boss.

[0106] The guide boss structure is used to arrange the pen cap spring 002.

[0107] The cap spring 002 is formed from a single spring wire through multiple bends. It has a first mounting portion 201 and a second mounting portion 202. The first mounting portion 201 is inserted into the axial end of the cap inner ring 102 and is secured to the transverse stopper 118. The first mounting portion 201 has a first mounting hook 211 secured to the guide step. The first mounting portion 201 also has a vertically bent portion 221 connected to the first mounting hook 211.

[0108] The vertical bend 221 extends axially toward the protruding end of the cap inner ring 102. The connection between the vertical bend 221 and the first hook 211 bends radially outward. This allows the first hook 211 to be hooked onto the transverse stop 118 and allows the vertical bend 221 to fall within the positioning groove formed by the vertical bend 228. The first hanging portion 201 has two parallel hook springs 231, each of which has a first hook 211 and a vertical bend 221. The distance between the two hook springs 231 is the width of the thin-walled structure 109 of the guide boss. In this embodiment, the distance between the two positioning grooves is substantially the same as the width of the thin-walled structure 109. The first hanging portion 201 includes a set of symmetrically arranged first hanging hooks 211 and vertical bending portions 221, which correspond to the pen cap ears 107 on the second side of the pen cap inner ring 102, forming a symmetrical hook structure through the radial direction of the pen cap inner ring 102 to ensure the stability of the installation structure of the pen cap spring 002.

[0109] The second hanging portion 202 is arranged at the extended end of the vertical bending portion 221 and extends above the pen cap inner ring 102. The extending height of the second hanging portion 202 is set according to the height of the needle guard cap after the needle guard cap is installed in the pen cap inner ring 102.

[0110] The second mounting portion 202 includes two compression springs 212 that span between a set of pen cap ears 107. After the needle guard is installed, the two compression springs 212 are respectively pressed against the radial edges of the needle guard. In this embodiment, the spacing between the two compression springs 212 at their midpoints only needs to be commensurate with the diameter of the needle guard. This allows the compression springs 212 to press against the edges of the needle guard. During the removal of the pen cap 001, the compression springs 212 hook and compress the needle guard, allowing it to be removed from the prefilled syringe.

[0111] The distance between the two hook spring wires 231 can be set to be greater than the outer diameter of the needle guard cap, or less than the outer diameter of the needle guard cap. Therefore, when preparing the compression spring wire 212, the distance between the hook spring wires 231 is designed according to the layout space of the width of the pen cap ear 107. When the distance between the two hook spring wires 231 is the same as the outer diameter of the needle guard cap, the compression spring wire 212 can be designed as a compression spring wire 212 with a straight structure; when the distance between the two hook spring wires 231 is less than the outer diameter of the needle guard cap, the compression spring wire 212 is designed as a compression spring wire 212 bent outward; when the distance between the two hook spring wires 231 is greater than the outer diameter of the needle guard cap, the compression spring wire 212 is designed as a compression spring wire bent inward.

[0112] The pen cap spring 002 is formed by bending a spring wire to form a first hook portion 201 that hooks with the pen cap inner ring 102, and a second hook portion 202 that hooks with the edge of the needle guard. The first end of the spring wire of the pen cap spring 002 is bent sequentially, starting from the first hook portion 211. After passing through a set of pen cap ears 107, the second end of the spring wire is bent back to be arranged parallel to the first end of the spring wire. The first and second ends of the spring wire are hidden and hung within the positioning step, ensuring the stability of the pen cap spring bending structure.

[0113] like Figure 6 As shown, Figure 6 Schematic diagram of the structure of the protective shell.

[0114] The first end of protective shell 003 features a mounting tube 301 that fits between the outer ring 101 and inner ring 102 of the pen cap. The insertion end of mounting tube 301 is equipped with an annular inner flange 303, with a mounting hole 304 defined in the center for the inner ring 102 to pass through. The inner circumference of annular flange 303 is provided with multiple mounting notches 305, corresponding to the external support ribs 105 of the inner ring 102. When protective shell 003 is installed in pen cap 001, each external support rib 105 aligns with a corresponding mounting notch 305. This not only prevents misalignment during assembly of protective shell 003 and pen cap 001, but also ensures circumferential torsional positioning through the external support ribs 105 and mounting notches 305, ensuring the stability of the mounting structure between pen cap 001 and protective shell 003.

[0115] The inner ring of the annular inner flange 303 is also provided with a limiting spring 307 corresponding to the position of a set of retaining springs 103 on the pen cap 001. The limiting spring 307 is integrally connected to the annular inner flange 303 and extends axially along the protective shell 003. A limiting notch is provided at the protruding end of the limiting spring 307. When the protective shell 003 is installed in the pen cap 001, the limiting spring 307 and the retaining spring 103 are aligned and squeezed together. After the protective shell 003 and the pen cap 001 are properly installed, the retaining teeth 104 on the retaining spring 103 fall into the limiting notch, preventing the axial sliding of the protective shell 003. The external support ribs 105 and the installation notch 305 provide circumferential rotational positioning. The axial retaining and limiting action of the limiting spring 307 and the retaining spring 103 ensure a tight fit between the pen cap 001 and the protective shell 003, ensuring structural stability after assembly.

[0116] The outer ring of the mounting cylinder 301 is set to a smooth structure, and the outer wall surface of the mounting cylinder 301 is interference fit with the inner support rib 106 of the pen cap outer ring 101, so that the protective shell 003 and the pen cap outer ring 101 and the pen cap inner ring 102 of the pen cap 001 are tightly assembled, ensuring the stability of the assembly structure of the two.

[0117] Protective housing 003 also includes a set of protective fins 302 radially extending from mounting barrel 301. These two fins 302 are positioned opposite each other, forming an observation channel between them for monitoring the status of the prefilled syringe 006 mounted therein. The protective fins 302 and mounting barrel 301 are concentrically arranged and integrally formed.

[0118] The protective fin 302 and the limiting spring 307 are located on the same side, corresponding to the position of the retaining spring 103 on the first side of the pen cap 001. This creates space for the retaining structure on the annular inner flange 303. The annular inner flange 303 also features a guide slot 306, a splined structure that corresponds to the spline teeth of the cap ear 107. The inner ring 102 and protective shell 003 are assembled into place using the guide boss and the guide slot sliding guide structure. The guide slot structure corresponds to the guide boss structure, ensuring that the inner ring 107 of the pen cap and the guide slot 306 also provide anti-twist protection, and achieving a compact assembly structure for the pen cap and protective shell.

[0119] In a preferred structure, the first side of the pen cap 001 corresponds to the first radial direction of the pen cap, and the second side corresponds to the second radial direction of the pen cap. The first and second sides of the pen cap are arranged substantially perpendicularly. This allows the pen cap 001 and the protective shell 003 to form a space for arranging the clip-on structure in the radial direction of the first side, and to form a space for arranging the guide boss and the observation channel in the radial direction of the second side.

[0120] Through the basically perpendicular cross arrangement structure on the first side and the second side of the pen cap 001, the second hanging part 202 of the pen cap spring 002 extends in the extension direction along the observation direction of the observation channel, and the press-fit spring wire 212 of the second hanging part 202 obtains a longer press-fit length. When the two opposite press-fit spring wires 212 are opened, a larger opening distance can be obtained, which is convenient for installing the needle guard cap of the prefilled syringe.

[0121] like Figure 7 and Figure 8 As shown, Figure 7 is a structural diagram of the bracket; Figure 8 This is a schematic diagram of the structure after the lower pen shell assembly is installed into the prefilled syringe.

[0122] The inner circle of the protective shell 003 is provided with a bracket 005, which is used to position and install the pre-filled syringe 006 in the lower pen shell assembly. The bracket 005 includes a bracket barrel portion 501 for lifting and supporting the bottle body of the syringe, and a first arm plate 502 and a second arm plate 503 are axially extended from the bracket barrel portion 501 for clamping and fitting the radial sides of the needle guard 601 of the prefilled syringe. An observation channel for the pen cap spring 002 connected to the observation channel is formed between the first arm plate 502 and the second arm plate 503. The second hanging portion 202 of the pen cap spring 002 is clamped to the axial end edge of the needle guard 601 by the first arm plate 502 and the second arm plate 503. The independently arranged first arm plate 502 and second arm plate 503 structures reserve the pen cap spring 002 hanging channel, and also form an observation window on the bracket 005 for observing the bottle body of the prefilled syringe, which is convenient for observing the liquid inside the injection bottle through the observation channel on the protective shell 003.

[0123] The end of the bracket barrel 501 connecting the first arm plate 502 and the second arm plate 503 is protruded inward and is provided with a pair of bracket protrusions 505, and the inner wall surface of the bracket protrusion 505 is provided with a bracket arc 506. The curvature of the bracket arc 506 fits with the curved surface of the bottle body of the prefilled syringe, so that the bottle body of the prefilled syringe 006 is positioned and assembled in the bracket barrel 501.

[0124] After the bottle holder of the prefilled syringe 006 is installed in the bracket barrel 501, its needle guard 601 extends from the bracket protrusion 505 and falls between the first arm plate 502 and the second arm plate 503. The inner wall surfaces of the first arm plate 502 and the second arm plate 503 have a bracket slope corresponding to the slope of the needle guard 601. The roots of the first arm plate 502 and the second arm plate 503 connecting to the bracket barrel 501 are both provided with a concave bracket groove 507. The second hanging portion 202 of the pen cap spring 002 extends into the roots of the first arm plate 502 and the second arm plate 503. After the prefilled syringe 006 is installed, the two compression spring wires 212 of the second hanging portion 202 are press-fitted onto the radial sides of the needle guard 601. At the same time, during the process of pulling out the pen cap 001, the bracket slopes of the first arm plate 502 and the second arm plate 503 are tightly fitted with the outer wall of the needle guard cap 601 to limit the two compression springs 212 of the second hanging part 202 to the axial edge of the needle guard cap 601. The compression spring 212 presses the needle guard cap 601 tightly and positions it in the pen cap 001, so that the needle part of the prefilled syringe 006 is pulled out from the needle guard cap.

[0125] A bracket boss 508 is provided on the outer peripheral surface of the bracket barrel 501, and the bracket boss 508 includes a pair of bracket bosses 508 respectively arranged on the outer wall surfaces at both radial ends of the bracket barrel 501, and the arrangement position of the bracket boss 508 is respectively arranged opposite to a group of protective fins 302 on the protective shell 003. The protective fin 302 is provided with a card slot 308 running through the thickness direction thereof. When the bracket 005 is installed into the protective shell 003, the bracket boss 508 on the bracket 005 falls into the card slot 308, so that the bracket 005 is axially positioned between the bracket boss 508 and the pen cap spring 002, thereby preventing the bracket 005 from falling out of the protective shell 003. The snap-in slot 308 is a strip-shaped slot extending axially from the protective fin 302. When the pen cap 001 is removed, the needle guard 601 is simultaneously pulled out by the pen cap spring 002. The bracket 005 has a fixed position at the pen cap end, allowing the bracket 005 to drive the needle structure of the prefilled syringe 006 out of the end of the protective shell 003 for injection. The strip-shaped snap-in slot 308 guides the axial sliding of the bracket 005.

[0126] The second hanging part 202 of the pen cap spring 002 has two compression spring wires 212 that overlap with the axial edge of the needle guard cap 601. When the prefilled syringe 006 is loaded into the bracket 005 and further loaded into the pen cap 001, the two compression spring wires 212 need to be opened so that the needle guard cap 601 of the prefilled syringe 006 can pass through the second hanging part 202 smoothly, avoiding obstruction between the compression spring wire 212 and the needle guard cap 601.

[0127] like Figure 9 and Figure 10 As shown, Figure 9 Schematic diagram of the structure of the pen shell; Figure 10 This is a cross-sectional view of the internal structure of the lower pen shell.

[0128] The present application further includes a lower pen housing 004, which is located on the outer ring of the protective housing 003. The lower pen housing 004 has a cylindrical structure, a lower pen housing outer cylinder 401, and a lower pen housing inner cylinder 402 arranged on the inner ring of the lower pen housing outer cylinder. A first connecting portion and a second connecting portion arranged radially are provided between the lower pen housing outer cylinder 401 and the lower pen housing inner cylinder 402.

[0129] An observation window 403 connected to the observation channel is also provided on the outer tube 401 of the lower pen shell. The observation window 403 includes a first observation window located at the first radial end of the outer tube 401 of the lower pen shell, and a second observation window located at the second radial end of the outer tube 401 of the lower pen shell. Both the first observation window and the second observation window have a flange folded from the outer wall surface of the lower pen shell outer tube 401 toward the inner wall surface.

[0130] The first connecting part is connected to the bottom of the first observation window, and the second connecting part is connected to the bottom of the second observation window, so that two semicircular ring gaps 404 are formed between the lower pen shell outer tube 401 and the lower pen shell inner tube 402, and the two protective fins 302 of the protective shell 003 pass through the two semicircular ring gaps 404 respectively and extend into the interior of the lower pen shell outer tube.

[0131] The inner wall surface of the inner cylinder of the lower pen shell is provided with a first lower pen shell protrusion 405 and a second lower pen shell protrusion (not shown in the figure). The first lower pen shell protrusion 405 and the second lower pen shell protrusion are both triangular protrusions. The maximum width of the triangular protrusion is greater than the width between the two vertical bends 221 of the pen cap spring 002. At the same time, the triangular protrusion extends into the vertical bend 221 of the pen cap spring 002 in the height direction. When the lower pen shell 004 is installed into the pen cap 001, the parallel vertical bends are connected by the triangular protrusions. 221 opens, the two compression spring wires 212 of the second hanging part 202 move away from each other and fall into the two bracket grooves 507 of the bracket 005 respectively. After the prefilled syringe 006 is loaded into the bracket 005, the lower pen shell 004 is dragged to slide upward, and the triangular protrusion is detached from the pen cap spring 002. The two compression spring wires 212 of the second hanging part 202 approach each other, are radially clamped in the bracket groove 507, and are clamped on the axial end edge of the needle guard cap 601, thereby completing the assembly of the lower pen shell assembly.

[0132] Based on the clamping structure of the pen cap 001, the protective shell 003, the bracket 005, the lower pen shell 004 and the prefilled syringe 006, the present application also provides a pre-assembly method of the lower pen shell assembly, comprising the following steps:

[0133] 1. Assemble the pen cap and pen cap spring;

[0134] The first hanging hooks 211 of the first hanging part 201 of the pen cap spring 002 are pressed toward each other and deformed, and the protruding end of the pen cap inner ring 102 is installed on the pen cap ear 107, so that the first hanging hooks 211 slide close to the lateral limit part 118 of the pen cap ear 107 and are clamped into the guide boss. At this time, the two vertical bent parts 221 of the first hanging hooks 211 fall into the two sides of the vertical limit part 128. After adjusting the first hanging hooks 211 on the first hanging part 201 and installing them on the pen cap ear 107, the assembly is completed.

[0135] 2. Assemble the protective case

[0136] Install the mounting tube 301 of the protective shell 003 into the pen cap 001, so that the guide slot 306 of the mounting tube 301 is arranged opposite to the pen cap ear 107, so that the mounting tube 301 slides axially along the pen cap inner ring 102 to the root of the pen cap 001, and the snap-fitting spring piece 103 and the limiting spring piece 307 fit tightly together until the snap-fitting tooth 104 of the snap-fitting spring piece 103 is snapped into the limiting notch at the top of the limiting spring piece 307, and then the protective shell 003 and the pen cap 001 are installed in place.

[0137] 3. Assemble the pen case

[0138] The two protective fins 302 of the protective shell 003 are passed through the two semicircular gaps 404 of the lower pen shell 004. The lower pen shell 004 is then inserted between the pen cap outer ring 101 and the protective shell 003. The end of the lower pen shell 004 overlaps the inner support rib 106 of the pen cap outer ring 101. As the lower pen shell 004 slides into the pen cap 001, the triangular tip of the triangular projection of the lower pen shell 004 falls between the two parallel vertical bends 221. As the lower pen shell 004 continues to move downward, the triangular projection reaches its maximum width, causing the two parallel vertical bends 221 to open, thereby causing the two compression spring wires 212 of the pen cap spring 002 to expand.

[0139] 4. Assemble the bracket

[0140] The observation window 504 of the bracket 005 is slid into the protective shell relative to the observation channel on the protective shell 003. During the sliding process, the bracket 005 slides into the bracket 005 until its bracket boss 508 is engaged with the engaging groove 308 on the protective fin 302. The bracket 005 is then installed in place. The two compression spring wires 212 of the pen cap spring 002 enter between the first arm plate 502 and the second arm plate 503 of the bracket. The position of the lower pen shell 004 is adjusted so that the two compression spring wires 212 are stretched by the triangular protrusions on the lower pen shell 004. The two compression spring wires 212 are respectively expanded into the bracket groove 507 of the bracket 005, forming a channel inside the bracket 005 for the prefilled syringe 006 to be installed.

[0141] The protective shell 003, with its protective fins 302, forms a fin spacing between the two protective fins 302 and a window spacing between the two observation windows, with the window spacing being greater than the fin spacing. The bracket 005 can be configured with different radial widths, corresponding to the window spacing and fin spacing, respectively, to achieve different aspect ratios for the bracket. This allows for positioning of the protective shell 003 and bracket 005 in the correct direction, reducing assembly difficulty.

[0142] 5. Assemble the prefilled syringe

[0143] The prefilled syringe 006 is loaded into the bracket 005, so that the bottle of the prefilled syringe 006 fits into the bracket protrusion 505 on the bracket 005 and the bottle is in close contact with the bracket arc 506. At this time, the needle guard 601 passes through the two compression spring wires 212 and extends into the pen cap 001. The pen housing 004 is adjusted to slide away from the pen cap 001, and the triangular protrusion slides out of the two parallel vertical bends 221 of the pen cap spring 002. The two compression spring wires 212 slide out of the bracket groove 507 due to their own elastic force and fall into the axial end edge of the needle guard 601, thus realizing the pen cap spring's removal mechanism for the needle guard.

[0144] like Figure 11 As shown, Figure 11 It is a schematic diagram of the assembly structure of the upper pen shell and the lower pen shell.

[0145] The upper pen housing assembly, which drives the prefilled syringe 006 for injection, comprises an upper pen housing 016 and a drive mechanism housed within it. The upper pen housing 016 is a plug-and-play fit within the lower pen housing 004. The lower pen housing 004 comprises an annular outer sleeve structure, comprising a lower pen housing outer barrel 401. The upper pen housing 016 comprises an annular inner sleeve 1601. These fit together, integrated into the lower pen housing outer barrel 401, via mounting bosses extending from the outer wall of the annular inner sleeve 1601 and mounting grooves within the inner wall of the annular outer sleeve structure.

[0146] like Figure 12-16 As shown, Figure 12 This is a cross-sectional view of the internal structure of the upper pen housing assembly; Figure 13 Schematic diagram of the internal structure of the upper pen housing assembly; Figure 14 A cross-sectional view of the directional slider structure of the upper pen housing assembly; Figure 15 Schematic diagram of the fixed sleeve structure in the upper pen housing assembly; Figure 16 This is a schematic diagram of the rotating slider structure of the upper pen housing assembly.

[0147] Arranged in the upper pen housing 016 are a directional slider 010 that is sequentially pushed by the protective housing, a rotating slider 009 arranged at the axial end of the directional slider 010 , and a fixed sleeve 007 that guides and supports the axial sliding of the directional slider 010 and the rotating slider 009 .

[0148] Both the directional slider 010 and the rotating slider 009 have a cylindrical structure. The directional slider 010 includes a driving fin 1001 that abuts against the two protective fins 302 of the protective shell 003, and a slider sleeve 1002 that fits around the outer periphery of the fixed sleeve. The rotating slider 009 also has a cylindrical structure and is rotatably arranged at the axial end of the slider sleeve 1002.

[0149] The outer wall surface of the fixed sleeve 007 is provided with a fixed sleeve groove 701 arranged along the axial direction, and the inner wall surface of the rotating slider 009 extends out of the rotating slider protrusion 901 sliding in the fixed sleeve groove 701. The fixed sleeve groove 701 has a predetermined guide length, which is determined by the length of the injection needle of the prefilled syringe exposed when the protective shell 003 slides along the axial direction.

[0150] A first torsion spring 008 is mounted on the fixed sleeve 007, which is connected to the rotating slider 009. A fixed sleeve groove is provided on the outer wall of the fixed sleeve 007. The fixed sleeve groove includes a fixed sleeve chute 701 and an impact step arranged on one circumferential side of the fixed sleeve chute 701. Specifically, the fixed sleeve groove includes a first recessed portion and a second recessed portion, which are connected. The first recessed portion forms the fixed sleeve chute 701; the second recessed portion includes a first step 702 and a second step 703, which are connected to the fixed sleeve chute 701 and arranged along the torsion direction of the first torsion spring. The first step 702 and the second step 703 are arranged sequentially along the extension direction of the first torsion spring 008. The fixed sleeve groove 701 has a first fixed sleeve notch 704 connected to the first step 702; there is a second fixed sleeve notch 705 between the first step 702 and the second step 703 to guide the first torsion spring 008 to rotate from the first step 702 to the second step 703. The first fixed sleeve notch 704 is a horizontal notch arranged along the circumferential direction, and the second fixed sleeve notch 705 is a vertical notch arranged along the axial direction. The fixed sleeve groove 701 is divided into two parts, a sliding part and an impact part, by the middle vertical plate 706.

[0151] When the injection is initiated, the protective shell 003 slides axially to expose the injection needle. The axial movement of the protective shell 003 pushes the directional slider 010 to slide. The directional slider 010 is provided with an inner slider protrusion 1004. The inner slider protrusion 1004 slides within the fixed sleeve slot 701. During the sliding process, the directional slider 010 pushes the rotating slider 009 to translate axially. The rotating slider protrusion 901 inside the rotating slider 009 also slides with the fixed sleeve slot 701, causing the rotating slider 009 to move axially along the fixed sleeve slot 701. A first torsion spring 008 is arranged between the rotating slider 009 and the fixed sleeve 007. The sliding of the rotating slider 009 compresses the first torsion spring 008, causing the rotating slider 009 to have a tendency to rotate. However, the fixed sleeve slot 701 blocks the rotating slider 009, causing it to slide axially within the fixed sleeve slot 701, providing only axial pressure on the first torsion spring 008.

[0152] When the directional slider 010 moves a certain distance, the elongated block 1003 provided on the inner side of the directional slider 010 abuts against the drive cover 015 provided in the drive structure of the upper pen shell 016, and the drive cover outer protrusion 1503 provided on the outer side of the drive cover 015, thereby limiting the injection action of the prefilled syringe.

[0153] During the axial movement of the directional slider 010 pushed by the protective shell 003, the outer protrusion 1503 of the driving cover and the long strip block 1003 are gradually separated. After the directional slider 010 slides a predetermined stroke, it reaches the injection position. At this time, the long strip block 1003 and the outer protrusion 1503 of the driving cover need to be separated, that is, the directional slider 010 slides axially to the unlocking position and enters the injection position.

[0154] By setting a rotating slider 009 at the axial end of the directional slider 010, after the directional slider 010 slides to the injection position, the rotating slider 009 is set to move to the first fixed sleeve notch 704. At this time, the first torsion spring 008 drives the rotating slider 009 to rotate, and the rotating slider protrusion 901 on the inner side of the rotating slider 009 hits the side wall at the first step 702 of the fixed sleeve groove 701 and makes a sound, so that the rotating slider cooperates with the fixed sleeve to produce an injection prompt sound to start the injection.

[0155] After the injection is completed and the injection needle is pulled out, the end of the protective shell 003 loses pressure and produces a return action. Specifically, the torsional pressure stored in the first torsion and compression spring 008 acts as a reaction force. The first torsion and compression spring 008 pushes the rotating slider 009 to slide, and further pushes the directional slider 010 to slide. The sliding of the directional slider 010 further pushes the protective shell 003 to move axially toward the injection needle.

[0156] During the sliding movement of the rotary slider 009, which is pushed by the first torsion spring 008, the rotary slider protrusion 901 adheres to the side wall at the first step 702 and slides along the first step 702. When the rotary slider protrusion 901 moves to the second fixed sleeve notch 705 at the connection between the first step 702 and the second step 703, the rotary slider 009 rotates toward the second step 703 under the torsional reaction force of the first torsion spring 008. The rotary slider protrusion 901 inside the rotary slider 009 strikes the fixed sleeve side wall at the second step 703. The collision of the rotary slider protrusion 901 and the second step 703 produces a sound, indicating that the protective shell 003 has fully returned to its original position. The collision sound also produces a warning sound of the protective locking function of the prefilled syringe. At this time, the protective shell 003 is pressed. Because the first step 702 and the second step 703 block the rotary slider 009 axially, the protective shell 003 will not slide axially, and the injection needle cannot be exposed, effectively preventing the injection needle from being reused. One end of the first torsion and compression spring 008 is connected to the fixed sleeve 007 , and the other end is fixed to the external mounting structure 902 on the outer periphery of the rotating slider 009 , so as to facilitate the installation and positioning of the first torsion and compression spring 008 .

[0157] like Figure 17 As shown, Figure 17 Schematic diagram of the screw drive structure in the upper pen housing assembly.

[0158] The drive cap 015 is part of the injection mechanism within the upper housing. A rotating sleeve 012 is mounted within the fixed sleeve 007. Inside this sleeve is a screw 017 that drives the prefilled syringe for injection. Rotating sleeve 012 is connected to the drive cap 015, which houses the sounding element 013.

[0159] After the drive cap 015 is unlocked, the first torsion spring 011, which is mounted on the outer ring of the rotating sleeve 012, is unlocked. The first torsion spring 011 is connected between the fixed sleeve 007 and the rotating sleeve 012, and a torque is stored in the first torsion spring 011. After unlocking, the torsion force of the first torsion spring 011 is released, driving the rotating sleeve 012 to rotate. This rotation of the rotating sleeve 012 drives the drive cap 015, which in turn drives the screw 017. The screw 017 passes through the nut 018 and rotates. The screw 017 moves, contacts the gasket 020, passes through the rear cover 019, and further pushes the stopper 021 of the prefilled syringe to initiate injection.

[0160] An annular inner cavity is provided in the driving cover 015, and a driving inner cylinder 1201 is provided on the rotating sleeve 012. The driving inner cylinder 1201 is inserted into the annular inner cavity of the driving cover 015. A plurality of axially extending card grooves and card-fitting ribs are provided on the outer wall surface of the driving inner cylinder 1201 and the inner wall surface of the annular inner cavity, so that the rotation of the rotating sleeve 012 drives the driving cover 015 to rotate synchronously.

[0161] By utilizing the annular inner cavity structure formed between the drive cap 015 and the rotating sleeve 012 and arranging a sounding member 013 within the annular inner cavity, after the injection structure is set, the sounding member 013 is driven to rotate and produce an injection completion sound, indicating that the injection is complete. The injection prompt sound can be implemented by arranging multiple rotating sounding member 013 structures within the annular inner cavity, and the sounding member 013 rotates within the annular inner cavity to produce a sound as the injection completion sound.

[0162] This application provides different sound piece 013 rotation structures, corresponding to Figure 1 and Figure 2 The preferred embodiment 1 and embodiment 2 are the sound member rotation structures, wherein embodiment 1 corresponds to Figure 1 , Example 2 corresponds to Figure 2 .

[0163] Example 1

[0164] like Figures 18-21 As shown, Figure 18 A schematic diagram of the first sound generating structure provided in this application; Figure 19 for Figure 18 Schematic diagram of the rotating sleeve structure; Figure 20 for Figure 18 Schematic diagram of the middle sounding member in the first direction; Figure 21 for Figure 18 Schematic diagram of the second direction of the middle sound component.

[0165] The inner wall of the driving inner cylinder 1201 is provided with a first groove 1202. This first groove 1202 has a guide slope 1203 extending from the base of the driving inner cylinder toward the cylinder opening. This guide slope 1203 extends to the middle of the cylinder height of the driving inner cylinder 1201. The inner wall of the driving inner cylinder 1201 is also provided with a second groove 1204, extending from the middle of the driving inner cylinder 1201 to the cylinder opening. The height direction of the driving inner cylinder 1201 refers to the direction extending from the bottom wall 1205 of the driving inner cylinder 1201 toward the cylinder opening.

[0166] The second groove 1204 has an impact side surface away from the guide bevel 1203. The side of the second groove 1204 close to the guide bevel 1203 forms an impact notch connecting the first groove 1202 and the second groove 1204. The first groove 1202 and the second groove 1204 are arranged as a set and in pairs on both sides of the driving inner cylinder 1201 in the radial direction.

[0167] The sounding member 013 is a columnar structure that rotates within the inner drive tube 1201. Two external sounding protrusions 1301 extend from its outer wall. In the initial position, these two external sounding protrusions 1301 rest on the bases of the two first grooves 1202 in the inner drive tube 1201. A second compression spring 0141 is also located within the drive cover 015. The first end of the second compression spring 0141 is connected to the drive cover 015, and the other end is connected to the sounding member 013.

[0168] The rotating sleeve 012 and the driving cover 015 rotate, driving the screw 017 to rotate continuously. When approaching the injection completion position, the tail of the screw 017 slides out from the driving inner cylinder 1201 of the rotating sleeve 012, and an axially arranged long strip protrusion 1701 is provided at the tail of the screw. The inner protrusion 1302 of the sound piece 013 extends radially from the inner wall surface of the sound piece, and the long strip protrusion 1701 and the inner protrusion 1302 of the sound piece are rotated and abutted in the axial direction.

[0169] The inner convex points 1302 of the sound member can be arranged in a plurality along the inner circumference of the sound member 013, and a driving gap is formed between adjacent inner convex points 1302 for the elongated protrusion 1701 to pass through. Preferably, the inner convex points 1302 of the sound member include two arranged along the radial direction of the sound member.

[0170] When the injection is nearly complete, the tail of the screw 017 enters the position of the driving inner cylinder 1201. The long strip protrusion 1701 at the tail of the screw 017 is clamped between the inner protrusions 1302 of the sounding member. The unreleased torsion spring force of the first torsion spring 011 further provides the rotational driving force of the rotating sleeve 012, thereby further rotating and feeding between the screw 017 and the nut 018. At this time, the sounding member 013 is driven by the long strip protrusion 1701 and the inner protrusion 1302 of the sounding member, causing the sounding member 013 to generate a rotational motion trend. Under the guidance of the guide bevel 1203, the sounding member 013 slides under the sliding guidance of the outer protrusion 1301 and the guide bevel 1203. When the sound piece 013 slides to the impact notch, it is acted upon by the torque provided by the screw 017, and disengages from the guide slope 1203, and quickly hits the impact side of the second groove 1204, making a sound. This sound is the injection completion prompt sound, and the second compression spring 0141 continuously provides axial pressure on the sound piece 013, so that the sound piece 013 is stably supported on the rotating sleeve 012.

[0171] Example 2

[0172] like Figure 22-Figure 25 As shown, Figure 22 A schematic diagram of the second sound generating structure provided in this application; Figure 23 for Figure 22 Schematic diagram of the rotating sleeve structure; Figure 24 for Figure 22 Schematic diagram of the middle sounding member in the first direction; Figure 25 for Figure 22 Schematic diagram of the second direction of the middle sound component.

[0173] In a specific embodiment of the present case, the annular inner cavity is arranged between the annular inner ring 1502 and the annular outer ring 1504 of the driving cover 015 , and the compression spring is sleeved on the annular inner ring 1502 .

[0174] The annular inner ring 1502 and the driving inner cylinder 1201 are provided with an axial sliding gap, and the inner ring of the sounding member 013 is provided with an inner protrusion 1302 of the sounding member extending into the sliding gap.

[0175] The tail of the screw 017 is provided with an axially arranged long strip protrusion 1701, and the axial end of the long strip protrusion 1701 is abutted against the inner protrusion 1302 of the sound member, so that the sound member slides axially.

[0176] Furthermore, a guide protrusion 1211 arranged along the axial direction extends from the inner wall surface of the driving inner cylinder 1201, and a sliding groove 1311 that slides and cooperates with the guide protrusion 1211 is provided on the outer wall surface of the sound member 013.

[0177] The guide protrusions 1211 and the sliding grooves 1311 include two groups respectively arranged at the radial ends of the driving inner cylinder 1201.

[0178] In a specific structure of this case, a head protrusion 1313 is provided on the head of the sounding member 013, and a driving cover protrusion 1501 is provided on the inner ring of the driving cover 015. The head protrusion 1313 and the driving cover protrusion 1501 collide and fit at the same radial position.

[0179] In this embodiment, the inner wall of the driving inner cylinder 1201 is provided with axially arranged guide protrusions 1211. The outer wall of the sounding member 013 is provided with sliding grooves 1311 that slidably engage with the guide protrusions 1211. The guide protrusions 1211 and sliding grooves 1311 comprise two sets, one at each radial end of the driving inner cylinder 1201. When the sounding member 013 is installed in the driving inner cylinder, it is axially compressed by the second torsion spring 014, positioning the sounding member 013 within the driving inner cylinder 1201.

[0180] The head of the sounding member 013 is provided with a head protrusion 1313, and the inner ring of the driving cover 015 is provided with a driving cover protrusion 1501. The head protrusion 1313 and the driving cover protrusion 1501 are located at the same radial position. Furthermore, the annular inner ring 1502 extending from the base of the driving cover 015 serves as a driving cover guide cylinder, and the driving cover protrusion 1501 is arranged on the outer circumference of the driving cover annular inner ring 1502. The sounding member 013 has a sounding member rotating cylinder 1314 that fits snugly with the driving cover annular inner ring 1502, and the head protrusion 1313 is arranged at the head of the sounding member rotating cylinder 1314.

[0181] Similarly, a long strip protrusion 1701 is provided at the tail of the screw 017, and an inner convex point 1302 of the sound piece is provided on the inner wall surface of the sound piece 013. In this embodiment, the long strip protrusion 1701 and the inner convex point 1302 of the sound piece are arranged relative to each other in the extension direction of the screw 017. When the screw 017 is fed to the tail of the screw, the long strip protrusion 1701 and the inner convex point 1302 of the sound piece are matched, so that the sound piece 013 slides axially until the sound piece 013 is The sliding groove 1311 of 13 is disengaged from the guide protrusion 1211, and the bottom surface of the sound piece 013 is a flat structure. The sound piece 013 is rotatably supported by the top of the guide protrusion 1211. Under the action of the second torsion spring 014, the torsional force stored in the second torsion spring 014 drives the sound piece 013 to rotate rapidly, and makes the head protrusion 1313 hit the drive cover protrusion 1501 during the rotation process, making a sound, which serves as the second injection structure prompt sound.

[0182] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A disposable injection pen, characterized in that: The pen case assembly comprises an upper pen case assembly and a lower pen case assembly that are assembled together. The lower pen case assembly comprises a pen cap and a protective shell that is clamped in the pen cap. The inner ring of the protective shell is provided with a bracket for supporting the prefilled syringe. The pen cap is provided with a pen cap spring extending toward the bracket, and the pen cap spring has a pressing portion for pressing the axial edge of the needle guard cap of the prefilled syringe; The pen cap spring comprises a first hanging portion fixedly connected to the pen cap, and a second hanging portion provided at an extended end of the first hanging portion; The pressing portion includes a first portion and a second portion which are provided on the second hanging portion and overlap the axial edge of the needle guard cap; The pen cap comprises a coaxial pen cap outer ring and a pen cap inner ring which are arranged in a sleeve, and the protective shell is clamped between the pen cap outer ring and the pen cap inner ring; The inner ring of the pen cap has a pen cap ear portion protruding in the radial direction, and the first hanging portion is clamped and connected to the pen cap ear portion; The first hanging portion includes a first hanging hook portion that is engaged with the pen cap ear portion, and a vertical bending portion connected to the first hanging hook portion and extending toward the bracket; The second hanging portion is provided at the protruding end of the vertical bending portion; The first hanging hook portion, the vertical bending portion and the second hanging portion are symmetrical structures formed by bending the same spring wire.

2. The disposable injection pen according to claim 1, characterized in that: The pen cap ears include two arranged at the radial ends of the inner ring of the pen cap, and the first hanging hook includes a group of hooks respectively hung on the two pen cap ears; The pressing part is two pressing spring wires spanning between the two pen cap ears.

3. The disposable injection pen according to claim 2, characterized in that: A spring limiting portion that cooperates with the pen cap spring is provided in the pen cap ear, and the spring limiting portion includes a transverse limiting portion that is engaged with the first hanging hook portion and a vertical limiting portion that separates the spring wires arranged in parallel.

4. The disposable injection pen according to claim 3, characterized in that: The two compression spring wires are straight compression spring wires or arc compression spring wires.

5. The disposable injection pen according to claim 4, characterized in that: The bracket includes a bracket tube portion for lifting and supporting the bottle body of the prefilled syringe, and a first arm plate and a second arm plate extending from the bracket tube portion, wherein the first arm plate and the second arm plate are pressed against both radial sides of the needle guard cap.

6. The disposable injection pen according to claim 5, characterized in that: The bracket tube is provided with two lifting protrusions for lifting the bottle body, and the first arm plate and the second arm plate are respectively connected to the two lifting protrusions; The roots of the first arm plate and the second arm plate are respectively provided with bracket grooves for accommodating the expansion of the two compression spring wires.

7. The disposable injection pen according to claim 6, characterized in that: It also includes a lower pen shell that is sleeved on the outer ring of the protective shell. The lower pen shell has a coaxially arranged lower pen shell outer cylinder and a lower pen shell inner cylinder. The inner wall of the lower pen shell inner cylinder is provided with a position corresponding to the vertical bending portion, which pushes the two compression spring wires to open into the bracket groove and contracts after the prefilled syringe is assembled in place, so that the compression spring wire overlaps the lower pen shell protrusion on the edge of the needle guard cap shaft end.

8. The disposable injection pen according to any one of claims 1 to 7, characterized in that: A fixed sleeve is provided in the upper pen housing assembly, and a rotating slider arranged to slide along the axial direction is provided on the fixed sleeve; The fixed sleeve guides the axial sliding of the rotary slider, and when the rotary slider slides axially to the unlocking position, drives the rotary slider to rotate so as to collide with the fixed sleeve to emit an unlocking prompt sound.

9. The disposable injection pen according to claim 8, characterized in that: The outer wall surface of the fixed sleeve is provided with a fixed sleeve groove, and the inner wall surface of the rotating slider is provided with a rotating slider protrusion; The fixed sleeve groove includes a fixed sleeve sliding groove for guiding the axial sliding of the rotary slider protrusion, and an impact step for impact cooperation with the rotary slider.

10. The disposable injection pen according to claim 9, characterized in that: The fixed sleeve is provided with a first torsion and compression spring, and the first torsion and compression spring is connected to the rotating slider; The first torsion spring provides axial elastic support to the rotary slider and drives the rotary slider to perform circumferential torsion.

11. The disposable injection pen according to claim 10, characterized in that: The impact step is a first step and a second step arranged in the fixing sleeve groove and along the torsion direction of the first torsion and compression spring. The first step and the second step are arranged sequentially along the extending direction of the first torsion and compression spring.

12. The disposable injection pen according to claim 11, characterized in that: The impact steps are both located on the first step and the second step and are step side walls opposite to the twisting direction of the protrusion of the rotary slider.

13. The disposable injection pen according to claim 12, characterized in that: The fixed sleeve slot has a first fixed sleeve notch connected to the first step; and a second fixed sleeve notch is provided between the first step and the second step for guiding the first torsion spring to rotate from the first step into the second step.

14. The disposable injection pen according to claim 13, characterized in that: The rotary slider is a cylindrical structured rotary slider, and the rotary slider is sleeved on the fixed sleeve.

15. The disposable injection pen according to claim 13, characterized in that: It also includes a sleeve on the fixed sleeve, driving the rotating slider to slide along the axial direction of the directional sleeve.

16. The disposable injection pen according to claim 15, characterized in that: A protective fin extends from the protective shell and contacts the fixing sleeve to push the fixing sleeve to move.

17. The disposable injection pen according to any one of claims 1 to 7, characterized in that: A rotating sleeve for driving the screw to perform the injection action is also provided in the upper pen housing assembly; The upper pen housing assembly is further provided with a sounding member that rotates synchronously with the rotating sleeve; At the end of the injection operation, the sounding member rotates circumferentially and collides with the rotating sleeve to emit an injection completion prompt sound.

18. The disposable injection pen according to claim 17, characterized in that: A drive cover that rotates synchronously is arranged at the protruding end of the screw of the rotating sleeve. An annular inner cavity is formed between the rotating sleeve and the drive cover, and the sounding member is arranged in the annular inner cavity.

19. The disposable injection pen according to claim 18, characterized in that: The screw rod can be arranged in the rotating sleeve in a spiral manner, and the tail of the screw rod is provided with a driving structure for driving the sounding member to rotate synchronously.

20. The disposable injection pen according to claim 19, characterized in that A compression spring for providing axial pressure to the sounding member is arranged in the driving cover; The end of the screw rod is provided with a driving inner cylinder, the first end of the compression spring is connected to the driving cover, and the second end of the compression spring is connected to the sounding member; The compression spring presses the sounding member tightly into the driving inner tube.

21. The disposable injection pen according to claim 20, characterized in that: The annular inner cavity is arranged between the annular inner ring and the annular outer ring of the driving cover, and the compression spring is sleeved on the annular inner ring; The annular inner ring and the driving inner cylinder are provided with an axial sliding gap, and the inner ring of the sounding member is provided with an inner protrusion of the sounding member extending into the sliding gap.

22. The disposable injection pen according to claim 21, characterized in that The tail of the screw is provided with an axially arranged long strip protrusion, and the circumferential end surface of the long strip protrusion abuts against the convex point inside the sound member to drive the sound member to rotate.

23. The disposable injection pen according to claim 22, characterized in that: The inner convex points of the sound member are arranged in a plurality along the circumference of the inner ring, and a driving gap is formed between adjacent inner convex points of the sound member for the elongated protrusion to pass through.

24. The disposable injection pen according to claim 23, characterized in that A first groove is provided on the inner wall surface of the driving inner cylinder, and the first groove has a guiding inclined surface extending from the root of the driving inner cylinder to the cylinder mouth; A second groove is further provided on the inner wall surface of the driving inner cylinder. The second groove has an impact side surface away from the guide inclined surface. A side of the second groove close to the guide inclined surface forms an impact notch connecting the first groove and the second groove. An outer sound convex point extends out from the outer wall surface of the sound piece, and the outer sound convex point is pressed tightly against the guide inclined surface.

25. The disposable injection pen according to claim 24, characterized in that The sound outer protrusions include two radially extending from both ends of the outer wall surface, and the first groove and the second groove include two groups arranged in the radial direction of the driving inner cylinder.

26. The disposable injection pen according to any one of claims 1 to 7, characterized in that: A rotating sleeve for driving the screw to perform the injection action is provided in the upper pen housing assembly; The upper pen housing assembly is further provided with a sounding member that rotates synchronously with the rotating sleeve; At the end of the injection operation, the sounding member slides axially and rotates to collide with the rotating sleeve to emit an injection completion prompt sound.

27. The disposable injection pen according to claim 26, characterized in that A drive cover that rotates synchronously is arranged at the protruding end of the screw of the rotating sleeve. An annular inner cavity is formed between the rotating sleeve and the drive cover, and the sounding member is arranged in the annular inner cavity.

28. The disposable injection pen according to claim 27, characterized in that The screw rod can be arranged in the rotating sleeve in a spiral manner, and the tail of the screw rod is provided with a driving structure for driving the sounding member to rotate synchronously.

29. The disposable injection pen according to claim 28, characterized in that A torsion and compression spring is arranged inside the driving cover to provide rotational torsion and axial pressure to the sounding member; The end of the screw rod is provided with a driving inner cylinder, the first end of the compression spring is connected to the driving cover, and the second end of the torsion compression spring is connected to the sounding member; The torsion compression spring presses the sounding member tightly into the driving inner tube.

30. The disposable injection pen according to claim 29, characterized in that The annular inner cavity is arranged between the annular inner ring and the annular outer ring of the driving cover, and the torsion spring is sleeved on the annular inner ring; The annular inner ring and the driving inner cylinder are provided with an axial sliding gap, and the inner ring of the sounding member is provided with an inner protrusion of the sounding member extending into the sliding gap.

31. The disposable injection pen according to claim 30, characterized in that The tail of the screw is provided with an elongated protrusion arranged along the axial direction, and the axial end of the elongated protrusion is matched with the convex point inside the sound piece, so that the sound piece slides along the axial direction.

32. The disposable injection pen according to claim 31, characterized in that The inner wall surface of the driving inner cylinder is provided with a guide protrusion arranged along the axial direction, and the outer wall surface of the sounding part is provided with a sliding groove that slides with the guide protrusion.

33. The disposable injection pen according to claim 32, characterized in that The guide protrusions and the sliding grooves include two groups respectively arranged at two radial ends of the driving inner cylinder.

34. The disposable injection pen according to claim 33, characterized in that A head protrusion is provided on the head of the sounding part, and a drive cover protrusion is provided on the inner ring of the drive cover. The head protrusion and the drive cover protrusion collide and fit at the same radial position.

Images