CN214596704U - Medicine injection mechanism - Google Patents

Abstract

The application relates to a medicine injection mechanism, which relates to the field of injectors and comprises a tubular shell, an injection screw and an injection driving assembly; the injection driving mechanism comprises a driving piece for driving the injection screw rod to rotate towards the injection rotation direction, a locking piece for limiting the circumferential direction of the driving piece and only capable of rotating towards the injection rotation direction, a driving support which is circumferentially and rotationally arranged in the tubular shell and axially locked with the tubular shell, and a tail cover which is axially and slidably arranged at the far end of the tubular shell and drives the driving support to rotate; the drive support is provided with a ratchet piece, the ratchet piece has an elastic pawl, ratchet convex teeth for the elastic pawl to abut are arranged at the far end of the drive piece, and the drive support only can drive the drive piece to synchronously rotate towards the injection rotation direction and drive the injection screw to rotate towards the injection rotation direction. The present application provides a drug injection mechanism that enables multiple injections.

Description

Medicine injection mechanism

Technical Field

The application relates to the field of injectors, in particular to a medicine injection mechanism.

Background

Existing drug injection devices are largely divided into two types: one is an automatic drug injection device that requires all the drug solution in the drug tube to be injected into the patient's body in one injection, i.e., the automatic drug injection device can be used only once; the other is a multi-injection medicine injection device, and when a user uses the multi-injection medicine injection device, the liquid medicine in the medicine tube can be injected into the body of the patient by dividing into several times. Since the multi-injection medicine injection device can be used several times, the requirements of patients are more satisfied. The structure of the existing medicine injection device for multiple injections is single, and the inventor needs to develop a new injection mechanism which can realize multiple injections and can be applied to the medicine injection device.

SUMMERY OF THE UTILITY MODEL

The present application provides a drug injection mechanism capable of achieving multiple injections.

The application provides a medicine injection mechanism, adopts following technical scheme:

a medicine injection mechanism comprises a tubular shell, an injection screw rod and an injection driving assembly, wherein the injection screw rod is spirally arranged on the tubular shell and can extend into a medicine tube retainer; defining the rotation direction of the injection screw rod when the injection screw rod moves towards the near end as the injection rotation direction, and defining the rotation direction of the injection screw rod when the injection screw rod moves towards the far end as the medicine feeding rotation direction; the injection driving assembly comprises a driving piece, a locking piece, a driving support and a tail cover, wherein the driving piece is sleeved outside the injection screw and used for driving the injection screw to rotate towards the injection rotation direction, the locking piece is used for limiting the circumferential direction of the driving piece and only can rotate towards the injection rotation direction, the driving support is circumferentially and rotatably arranged in the tubular shell and axially locked with the tubular shell, and the tail cover is axially slidably arranged at the far end of the tubular shell and drives the driving support to rotate; the drive support is provided with a ratchet wheel piece at the near end, the ratchet wheel piece has an elastic pawl, ratchet wheel convex teeth for the elastic pawl to abut against are arranged at the far end of the drive piece, and the drive support has and can only drive the drive piece to synchronously rotate towards the injection rotation direction and drive the injection screw to rotate towards the injection rotation direction.

By adopting the technical scheme, the medicine injection mechanism comprises the medicine feeding operation and the injection operation in the using process.

The loading operation of the drug injection mechanism is as follows: the user drives the support and rotates certain angle towards the direction of rotation of adding medicine, because the cooperation of ratchet piece and ratchet protruding tooth and the restriction of locking piece to the driving piece for the drive support is at the in-process of rotating certain angle towards the direction of rotation of adding medicine, and the driving piece keeps motionless in week.

The injection operation of the drug injection mechanism is as follows: the user will then rotate the drive bracket to the initial position in the injection rotational direction, and due to the engagement of the ratchet member and the ratchet teeth, the drive member drives the injection screw to rotate in the injection rotational direction, so that the injection screw is advanced toward the proximal end.

When the medicine injection device needs to be used again for injection, a user only needs to rotate the driving support again along the medicine feeding rotation direction and drive the driving support to reset. The medicine injection device meets the requirement that the medicine injection mechanism can realize multiple injections.

According to the medicine injection device, the driving support, the ratchet wheel piece and the ratchet wheel convex teeth are arranged, so that the medicine feeding operation exists in the use process of the medicine injection device, the driving piece is not driven to act in the medicine feeding operation process, and the control of the displacement of the injection screw rod in single injection and the quantity of the medicine output from the cassette type bottle are facilitated.

Optionally, the driving support is axially provided with a driving spiral groove on the outer side wall of the distal end portion, and the tail cover is provided with a driving protrusion inserted into the driving spiral groove; when the tail cover is pulled out from the initial position towards the far end direction, the tail cover drives the driving bracket to rotate along the medicine feeding rotating direction; when the tail cap is pressed back to the initial position in the proximal direction, the tail cap drives the driving bracket to rotate in the injection rotation direction.

Through adopting above-mentioned technical scheme, above-mentioned medicine injection mechanism realizes the operation of adding medicine through extracting the tail-hood to realize the injection operation through pushing down the tail-hood, make the operation of adding medicine of medicine injection device and injection operation all comparatively convenient.

Optionally, the tail cover is provided with a tail end chute arranged axially, and the tubular shell is provided with a tail end convex tooth capable of sliding in the tail end chute.

Through adopting above-mentioned technical scheme, the tail end dogtooth can slide in the tail end spout, and the displacement volume of tail-hood in the operation of adding medicine and injection operation has been injectd to the length of tail end spout to can combine the pitch of drive helical groove on the drive support, thereby control drive support's rotation angle, and the liquid medicine injection quantity of control medicine injection device in once injection.

Optionally, the drive bracket has a bracket chuck; the tubular shell is provided with a support convex ring in the circumferential direction of the inner wall, a locking cylinder is arranged on the far end face of the support convex ring, a first pressing buckle is arranged on the side wall of the locking cylinder, and a support gap for the support clamping disc to be arranged is formed between the first pressing buckle and the support convex ring.

Through adopting above-mentioned technical scheme, disclosed the mounting means of drive support in tubular casing, this kind of mounting means simple structure, it is less to the interference of drive support's circumferential direction rotation, and comparatively ideal to drive support's axial locking effect.

Optionally, a bracket mounting post is arranged at the proximal end of the driving bracket, and a first guide groove is axially formed in the outer side wall of the bracket mounting post; the ratchet wheel piece is sleeved on the outer side of the support mounting column; the ratchet member has a ratchet guide inserted into the first guide groove.

Through adopting above-mentioned technical scheme, disclosed the cooperation mode of ratchet piece and drive support, drive support and ratchet piece circumference locking for when drive support rotates, ratchet piece can rotate in step.

Optionally, at least one locking protruding strip is axially arranged on the inner wall of the tubular casing, and the locking piece is provided with a locking guide groove for slidably matching the locking protruding strip.

Through adopting above-mentioned technical scheme, disclosed the circumference locking of lock piece and tubular casing, and the concrete structure that the lock piece can axially slide in tubular casing.

Optionally, the locking member is located at a distal side of the driving member, the driving member is provided with a first tooth surface structure at the distal end, and the locking member has a second tooth surface structure capable of meshing with the first tooth surface structure; a pressure spring is also arranged in the tubular shell, so that the first tooth surface structure is always meshed with the second tooth surface structure.

Through adopting above-mentioned technical scheme, disclosed the lock piece and limited the driving piece and have and can only follow the specific structure that injection direction of rotation rotated in circumference. Under the action of the first tooth surface structure, the second tooth surface structure and the pressure spring, when the driving piece is subjected to torque in the injection rotation direction, the driving piece rotates in the injection rotation direction to drive the locking piece to axially reciprocate; when the driving piece is subjected to torque in the direction of the medicine feeding rotation, the driving piece and the locking piece are kept static.

Optionally, the driving member is provided with a ratchet groove at a distal end, and the ratchet convex teeth are arranged on an inner wall of the ratchet groove; the ratchet member is disposed within the ratchet groove.

Through adopting above-mentioned technical scheme, the ratchet piece arranges in the ratchet groove of driving piece, has improved the cooperation stability between drive support, driving piece and the ratchet piece, has reduced the probability that the dislocation takes place for the ratchet dogtooth on ratchet piece and the driving piece.

Optionally, the ratchet groove is provided with a locking convex tooth at one side of the ratchet convex tooth towards the medicine feeding rotation direction; and a locking gap arranged at the end part of the elastic pawl is formed between the locking convex tooth and the ratchet convex tooth.

Through adopting above-mentioned technical scheme, the settlement of locking dogtooth makes and need overcome great resistance when rotating drive bracket along the rotational direction of adding medicine, has reduced drive bracket and has taken place the probability of maloperation in the transportation.

In summary, the present application includes at least one of the following beneficial technical effects:

1. a medicine injection mechanism comprises a tubular shell, an injection screw and an injection driving mechanism, wherein the injection driving mechanism comprises a driving piece, a locking piece and a driving bracket, a user can rotate the driving bracket along the medicine feeding and injection direction to realize the medicine feeding operation, and then the driving bracket is reset along the injection rotation direction to realize the injection operation, so that the medicine injection mechanism can perform the operation of multiple injections;

2. by arranging the tail cap which is arranged at the distal end part of the tubular shell in an axial sliding manner, a user can realize the medicine feeding operation by pulling out the tail cap and then press down the tail cap to realize the injection operation, so that the medicine feeding operation and the injection operation of the medicine injection device are both convenient and fast;

3. the ratchet groove is arranged at the far end of the driving piece, and the ratchet convex teeth are arranged on the inner wall of the ratchet groove, so that the matching stability among the driving support, the driving piece and the ratchet piece is improved, and the probability of dislocation of the ratchet convex teeth on the ratchet piece and the driving piece is reduced;

4. the locking convex teeth are arranged on the inner wall of the ratchet groove, so that the resistance of the medicine feeding operation is increased, and the risk of the medicine feeding operation of the medicine injection mechanism by misoperation is reduced.

Drawings

Fig. 1 is a schematic view of the structure of a drug injection mechanism.

Fig. 2 is an exploded schematic view of a drug injection mechanism.

Fig. 3 is a cross-sectional view of the rear housing at the first cog.

Fig. 4 is a schematic cross-sectional view of the rear housing with the rear housing projecting at the trailing lobe.

Fig. 5 is a schematic view of the structure of the connector.

Fig. 6 is a schematic cross-sectional view of a connector.

Fig. 7 is a schematic view of the structure of the injection screw.

Fig. 8 is a schematic cross-sectional view of the drive member.

FIG. 9 is a schematic view of the drive member showing its distal configuration.

Fig. 10 is an enlarged view at a of fig. 9.

Fig. 11 is a schematic view of the structure of the driving bracket.

FIG. 12 is a cross-sectional view of the rear housing, drive bracket, compression spring, locking member and ratchet member.

FIG. 13 is an exploded view of the drive bracket, compression spring, locking member, ratchet member and driving member.

FIG. 14 is a schematic view of the latch member showing the distal surface thereof.

FIG. 15 is a schematic view of the engagement of the drive member and the ratchet member.

Fig. 16 is an enlarged view at B in fig. 15.

Fig. 17 is a schematic structural view of the tail cap.

FIG. 18 is a schematic cross-sectional view of the tail cap at the limit slide.

Description of reference numerals: 1. a rear housing; 11. a bracket convex ring; 12. a first chamber; 13. a second chamber; 14. a locking cylinder; 141. limiting slots; 142. a limiting socket; 15. first pressing and buckling; 151. a first buckle tooth; 152. a first press buckle inclined plane; 153. a first press-fit end face; 154. a bracket gap; 16. a tail end convex tooth; 17. locking convex strips; 18. a rear clamping hole; 2. a connecting seat; 21. a rear connection portion; 211. a rear buckle is arranged; 2111. the convex part is buckled; 22. connecting the partition boards; 23. a partition structure portion; 24. a distal chamber; 25. a proximal chamber; 26. driving the stud; 261. a threaded hole; 27. a support cylinder; 3. an injection screw; 31. a screw plane; 32. a screw rod chute; 321. opening the screw; 33. a clamping head; 34. an injection push seat; 4. a drive member; 41. a drive section; 411. a drive aperture; 412. a drive plane; 413. driving the slide block; 42. an intermediate portion; 43. a control unit; 431. a ratchet groove; 432. ratchet wheel convex teeth; 4321. a guide slope; 4322. a cut-off end face; 433. a locking lobe; 4331. a locking bevel; 434. a locking clearance; 44. a first tooth surface configuration; 441. a first lobe; 4411. a first guide surface; 4412. a first locking surface; 5. a drive bracket; 51. a bracket mounting post; 511. a first guide groove; 5111. a guide opening; 52. the bracket is clamped with the flange; 53. driving the tail column; 531. driving the spiral groove; 5311. a spiral opening; 54. a bracket through hole; 6. a pressure spring; 7. a locking member; 71. a locking sleeve; 72. a support ring plate; 721. a locking guide groove; 73. a second tooth surface structure; 731. a second lobe; 7311. a second guide surface; 7312. a second locking surface; 8. a ratchet member; 81. a ratchet ring; 811. a ratchet wheel guide bar; 82. an elastic pawl; 821. a connecting section; 822. a drive section; 8221. a drive lobe; 8222. a drive end face; 9. a tail cover; 91. a tail end chute; 92. driving the inner cylinder; 921. a limiting slide bar; 922. the boss is driven.

Detailed Description

The present application is described in further detail below with reference to figures 1-18.

In the present application, when the term "distal part/end" is used, this refers to the part/end of the medicament injection device or the components thereof that is remote from the injection area of the human body during injection; accordingly, when the term "proximal part/end" is used, this refers to the part/end of the medicament injection device or the parts/ends of the members thereof which are close to the injection area of the human body during injection. And, positioning a state before the medicament injection apparatus is not used as an initial state of the medicament injection apparatus

The embodiment of the application discloses a medicine injection mechanism. Referring to fig. 1 and 2, the medicine injection mechanism includes a tubular housing, an injection screw 3 screw-mounted on the tubular housing, and an injection drive assembly mounted on the tubular housing and driving the injection screw 3 to axially advance. The injection drive assembly comprises a drive member 4, a drive bracket 5, a compression spring 6, a locking member 7, a ratchet member 8 and a tail cap 9. Wherein the driving member 4, the driving bracket 5, the pressure spring 6, the locking member 7 and the ratchet member 8 are all located within a tubular housing, and the tail cap 9 is mounted at the distal end portion of the tubular housing.

Referring to fig. 1, the tubular housing is not circular in cross-section and includes symmetrically arranged arcuate segments and symmetrically arranged straight segments such that the outer sidewall of the tubular housing includes symmetrically arranged housing arcs and symmetrically arranged housing planes. The tubular housing comprises a rear housing 1 and a coupling socket 2 mounted at a proximal end of the rear housing 1.

Referring to fig. 3, the rear case 1 has a hollow tubular structure. The rear housing 1 is provided with a bracket collar 11 on the inner wall near the distal end. The stent collar 11 is perpendicular to the axis of the rear housing 1, and the stent collar 11 divides the inner cavity of the rear housing 1 into a first chamber 12 at the proximal end and a second chamber 13 at the distal end.

Referring to fig. 3, the stent collar 11 is provided with a distally extending locking barrel 14 at the distal face. A locking cylinder 14 is located within the second chamber 13 and is arranged coaxially with the rear housing 1.

Referring to fig. 3, the locking cylinder 14 is provided with three first press buttons 15 having elasticity on an inner wall. The three first press studs 15 are arranged circumferentially and uniformly. The distal end of the first press stud 15 is connected to the locking barrel 14. The first press stud 15 is provided with a first stud tooth 151 at an inner wall. The three first fastening teeth 151 have a first press-fastening slope 152 at the distal end and a first press-fastening end face 153 at the proximal end. When the first crimp ramp 152 is subjected to distal-to-proximal pressure, the first crimp 15 deflects radially outward. A circumferentially arranged stent gap 154 is formed between the region enclosed by the three first buckling teeth 151 and the stent convex ring 11.

Referring to fig. 3, the locking cylinder 14 is further provided with two limiting slots 141 uniformly in the circumferential direction on the side wall. The retaining slot 141 extends through the sidewall of the locking barrel 14 and is parallel to the axis of the locking barrel 14. The retaining socket 141 is formed with a retaining socket 142 at the distal end of the locking barrel 14.

Referring to fig. 4, the rear housing 1 is further provided with two symmetrical tail teeth 16 on the inner wall of the distal end. Two tail teeth 16 are located in the second chamber 13, and the tail teeth 16 are located on the inner wall corresponding to the housing arc.

Referring to fig. 4, four locking ribs 17 are uniformly distributed on the inner wall of the first chamber 12 in the circumferential direction of the rear housing 1. Four locking ribs 17 are parallel to the axis of the rear housing 1. One end of the locking protrusion 17 is connected to the bracket protrusion ring 11, and the other end extends to the proximal end portion of the rear case 1. The rear shell 1 is also symmetrically provided with two rear clamping holes 18 at the proximal part. The two rear clamping holes 18 are rectangular holes and penetrate through the inner surface and the outer surface of the rear shell 1.

Referring to fig. 5, the connector includes a rear connector portion 21 fitted to the rear housing 1 and a connector spacer 22 against which the proximal end of the rear housing 1 abuts.

Referring to fig. 4 and 5, the rear connection portion 21 can be inserted into the proximal opening of the rear housing 1. Two rear buckles 211 are symmetrically arranged on the outer wall of the rear connecting part 21, and the far ends of the rear buckles 211 are connected with the rear connecting part 21, so that the rear buckles 211 can elastically deflect in the radial direction when bearing external force. Rear clasp 211 is also provided with a rear clasp protrusion 2111 at the proximal end. When the rear connecting portion 21 is fitted into the proximal end opening of the rear housing 1, the rear snap protrusions 2111 snap into the rear snap holes 18, and the proximal end of the rear housing 1 abuts on the connecting bulkhead 22.

When it is desired to remove the connector from the rear housing 1, the connector can be pulled out from the proximal opening of the rear housing 1 by pressing the rear latching protrusion 2111 inward, so that the rear catch 211 deflects inward and the rear latching protrusion 2111 is disengaged from the rear latching hole 18.

Referring to fig. 6, the connector is provided with a partition member 23 in the cavity. The partition structure portion 23 is integrally provided with the connector, and is perpendicular to the axis of the connector. The partition structure 23 divides the lumen of the connector into a distal chamber 24 near the distal end and a proximal chamber 25 near the proximal end. The partition structure portion 23 is provided with a drive stud 26 in a central region. The drive stud 26 axially penetrates the partition structure portion 23. The drive stud 26 is provided with an axially arranged threaded bore 261. A threaded bore 261 extends axially through the drive stud 26, and the axis of the threaded bore 261 coincides with the axis of the connection.

Referring to fig. 6, the partition structure portion 23 is further provided with a support cylinder 27 at the distal end surface. The support cylinder 27 is arranged coaxially with the connector and the height of the support cylinder 27 is greater than the depth of the distal chamber 24 so that the support cylinder 27 extends partially out of the distal chamber 24.

Referring to fig. 6 and 7, the injection screw 3 is threadedly mounted on the threaded bore 261 of the drive stud 26. When the injection screw 3 is mounted in the threaded hole 261, the injection screw 3 is axially arranged, and proximal or distal movement of the injection screw 3 can be achieved by rotating the injection screw 3. Wherein, when the injection screw 3 is moved toward the proximal end, the rotational direction of the injection screw 3 is defined as the injection rotational direction; when the injection screw 3 is moved distally, the rotational direction of the injection screw 3 is defined as the drug-feeding rotational direction. In this embodiment, the injection rotation direction is a counter-clockwise rotation direction and the administration rotation direction is a clockwise rotation direction when viewed from the distal end to the proximal end.

Referring to fig. 7, the injection screw 3 is provided with two screw planes 31 symmetrically in the circumferential direction of the outer wall. The two screw planes 31 are both provided with screw chutes 32 in the middle in the width direction, the screw chutes 32 are parallel to the axis of the injection screw 3, and the screw chutes 32 are formed with screw openings 321 at the proximal ends of the injection screw 3. The injection screw 3 is also provided with a snap joint 33 at the proximal end. An injection pushing seat 34 is installed on the clamping head 33, and the injection pushing seat 34 is provided with a clamping groove for clamping the clamping head 33.

Referring to fig. 8, the driving member 4 has a stepped tubular structure and includes a driving portion 41, an intermediate portion 42 and a control portion 43 in sequence in a proximal-to-distal direction. The outer diameters of the driving portion 41, the intermediate portion 42, and the control portion 43 are gradually increased.

Referring to fig. 7 and 8, the driving portion 41 has a driving hole 411 through which the injection screw 3 passes, and the driving hole 411 has a driving plane 412 in an inner wall thereof, which is in contact with the screw plane 31. The drive hole 411 is further provided with a drive slider 413 on the drive plane 412, and the drive slider 413 can be inserted into the screw sliding groove 32, so that the front drive 4 and the injection screw 3 are axially locked and can axially slide relative to each other.

Referring to fig. 8, the intermediate portion 42 is hollow.

Referring to fig. 9, the control portion 43 is provided with a ratchet groove 431 at a distal end. The ratchet grooves 431 are provided with two ratchet teeth 432 at intervals and uniformly in the circumferential direction of the inner wall. The side surface of the ratchet tooth 432 has a guide inclined surface 4321 and a cut-off end surface 4322, and the guide inclined surface 4321 is located on the side of the cut-off end surface 4322 facing the injection rotation direction. The ratchet groove 431 is further provided with a locking tooth 433 on one side of the ratchet tooth 432 in the drug administration rotation direction. A locking gap 434 is formed between the locking tooth 433 and the ratchet tooth 432, and a locking inclined surface 4331 is provided on a side of the locking tooth 433 facing the ratchet tooth 432.

Referring to fig. 9 and 10, the control portion 43 is provided with a first tooth surface structure 44 on a distal end surface. The first tooth flank configuration 44 consists of a ring of first teeth 441. The first convex tooth 441 has a first guide surface 4411 and a first lock surface 4412, and the first guide surface 4411 is located on the side of the first lock surface 4412 toward the injection rotation direction.

Referring to fig. 11, the drive bracket 5 includes, in order in a proximal-to-distal direction, a bracket mounting post 51, a bracket catch plate 52, and a drive tail post 53. The holder mounting post 51, the holder chuck 52 and the drive tail post 53 are coaxially arranged, and the drive holder 5 also has a holder through-hole 54 axially penetrating and through which the injection screw 3 passes.

Referring to fig. 11, the bracket mounting post 51 is provided with two first guide grooves 511 on an outer wall. The two first guide grooves 511 are arranged centrally symmetrically with respect to the bracket mounting post 51. The two first guide grooves 511 are parallel to the axis of the bracket mounting post 51, and the two first guide grooves 511 are formed with guide openings 5111 on the proximal end face of the mounting post.

Referring to fig. 11, the driving tail cylinder 53 is formed with a driving spiral groove 531 on an outer wall thereof. The drive helical groove 531 is formed with a helical opening 5311 in the distal end face of the drive tail post 53. Wherein the driving spiral groove 531 is spirally arranged in the injection rotation direction from the proximal end to the distal end.

Referring to fig. 12, the drive bracket 5 can be inserted into the inner cavity of the rear case 1 from the distal end opening of the rear case 1.

Referring to fig. 12, the outer diameter of the bracket mounting post 51 is smaller than the aperture of the region enclosed by the three first fastening teeth 151, the outer diameter of the bracket clamping disk 52 is larger than the aperture of the region enclosed by the three first fastening teeth 151, and the outer diameter of the driving tail post 53 is also smaller than the aperture of the region enclosed by the two first fastening teeth 151, so that in the process of mounting the driving bracket 5 from the distal opening of the rear housing 1 to the inner cavity of the rear housing 1, the bracket clamping disk 52 abuts against the first pressing and fastening inclined surface 152 of the first fastening teeth 151, so that the first pressing and fastening 15 is turned radially outwards, after the bracket clamping disk 52 passes through the first fastening teeth 151, the bracket clamping disk 52 is axially locked in the bracket gap 154, and the first pressing and fastening 15 is restored to the original state. At this point, the carrier mounting post 51 is located in the first chamber 12 and the carrier chuck disk 52 and drive tail post 53 are located in the second chamber 13.

Referring to fig. 12, the compression spring 6, the locking member 7, and the ratchet member 8 are sequentially fitted over the bracket mounting post 51 in a proximal-to-distal direction, with the compression spring 6, the locking member 7, and the ratchet member 8 arranged in a distal-to-proximal direction. The pressure spring 6, the locking member 7 and the ratchet member 8 are located in the first chamber 12 of the rear housing 1.

Referring to fig. 12, one end of the pressure spring 6 abuts on the proximal end face of the holder collar 11, and the other end abuts on the lock 7. After the injection mechanism is mounted, the pressure spring 6 forces the locking member 7 to have a tendency to slide in the proximal direction all the time.

Referring to fig. 12 and 13, the lock member 7 includes a lock sleeve 71 and a support ring plate 72. The locking sleeve 71 is disposed outside of the bracket mounting post 51. A support ring plate 72 is attached to the proximal end of the locking sleeve 71, with the support ring plate 72 being perpendicular to the axis of the locking sleeve 71. Wherein the proximal end of the pressure spring 6 abuts on the distal end face of the support ring plate 72. The supporting ring plate 72 is provided with four locking guide grooves 721 uniformly in the circumferential direction. The four locking guide slots 721 are all parallel to the axis of the bracket mounting post 51. When the lock member 7 is mounted on the rear housing 1, the lock protrusion 17 is engaged with the lock guide slot 721, so that the lock member 7 can slide axially relative to the rear housing 1 and cannot rotate circumferentially relative to the rear housing 1.

Referring to fig. 14, the support ring plate 72 is provided with a second tooth surface structure 73 on the proximal end face. The second tooth flank configuration 73 may engage the first tooth flank configuration 44. The second tooth surface structure 73 comprises four circumferentially evenly arranged tooth segments, and each tooth segment is formed by a plurality of circumferentially arranged second teeth 731. The second convex tooth 731 includes a second guide surface 7311 and a second locking surface 7312, and the second locking surface 7312 is located at one side of the second guide surface 7311 toward the injection rotation direction.

Referring to fig. 15, the ratchet member 8 includes a ratchet ring 81 and two elastic pawls 82. The inner wall of the ratchet ring 81 is provided with two ratchet guide bars 811. Two ratchet bars 811 are arranged symmetrically about the axis of ratchet ring 81, and ratchet bars 811 are parallel to the axis of ratchet ring 81. The ratchet guide 811 can slide into the first guide slot 511 of the bracket mounting post 51 through the guide opening 5111.

Referring to fig. 13, the two elastic pawls 82 are elastic arc-shaped strip-shaped structures, and the two elastic pawls 82 are circumferentially and uniformly distributed on the outer side wall of the ratchet ring 81. Resilient pawl 82 has a connecting section 821 attached to the outer wall of ratchet ring 81 and a drive section 822 extending in the injection rotational direction and circumferentially outward. A gap is formed between the drive section 822 and the ratchet ring 81. The driving segments 822 are resilient and can deflect radially when subjected to an external force. The driving section 822 is provided with a driving convex tooth 8221 at the outer side wall of the end far away from the connecting section 821, and the driving convex tooth 8221 has a driving end surface 8222 at the end far away from the connecting section 821.

Referring to fig. 14 and 15, the ratchet member 8 is fitted in the ratchet groove 431 of the rear control portion 43. During the process of mounting the ratchet member 8 to the ratchet groove 431, the elastic pawls 82 need to be pressed inward so that the driving sections 822 are deformed so that the elastic pawls 82 do not interfere with the distal end surface of the control portion 43. When the elastic pawl 82 is mounted in the inner cavity of the control portion 43, the driving convex tooth 8221 has a tendency to always abut on the inner wall of the ratchet groove 431. When the medicine injection device is in the initial state, the driving protrusion 8221 of the ratchet member 8 is located in the ratchet groove 431 of the rear drive member 4, and the driving protrusion 8221 is located in the locking gap 434.

Referring to fig. 4 and 17, the tail cap 9 is axially slidably mounted at the distal end of the rear housing 1. The outer side wall of the tail cap 9 is adapted to the shape of the distal opening of the rear housing 1. The outer side wall of the tail cap 9 comprises symmetrically arranged outer arc surfaces and symmetrically arranged outer planes. The tail cover 9 is symmetrically provided with two tail sliding grooves 91 on two outer arc surfaces, and the length directions of the two tail sliding grooves 91 are parallel to the length direction of the tail cover 9. When the tail cap 9 is mounted on the distal end of the rear housing 1, the tail teeth 16 are caught in the tail slide grooves 91 and restrict the displacement amount of the tail cap 9 in the axial direction.

Referring to fig. 17, the tail cap 9 has a coaxially arranged drive inner barrel 92. Drive barrel 92 is also arranged with drive boss 922 on the proximal inner wall. The driving protrusion 922 is a cylindrical protrusion and can be inserted into the driving spiral groove 531 of the driving bracket 5.

Referring to fig. 3 and 18, the driving inner cylinder 92 is provided with two circumferentially symmetrically arranged limit slides 921 on the outer side wall. The limiting slide strip 921 is parallel to the axis direction of the inner cylinder. When the tail cover 9 is mounted on the distal end of the rear housing 1, the limiting slide 921 is inserted into the limiting slot 141, so that the tail cover 9 cannot rotate circumferentially relative to the rear housing 1.

Referring to fig. 2, when the tail cap 9 is pulled/pressed, the driving bracket 5 can perform a corresponding circumferential rotation. When the tail cover 9 is pulled out towards the far end direction, the driving bracket 5 rotates 720 degrees towards the medicine feeding rotation direction; when the tail cap 9 is displaced in the proximal direction, the drive carrier 5 is rotated 720 ° in the injection rotation direction.

Referring to fig. 1 to 18, the use steps of the above-described medicine injection mechanism mainly include a medicine application operation and an injection operation.

When the medicine injection mechanism is used for medicine feeding operation, a user pulls out the tail cap 9 towards the distal direction, the driving protrusion 922 of the tail cap 9 is matched with the driving spiral groove 531 of the driving support 5, the driving support 5 rotates 720 degrees towards the medicine feeding rotation direction and drives the ratchet member 8 to rotate towards the medicine feeding rotation direction in the ratchet groove 431, and the driving convex tooth 8221 of the ratchet member 8 sequentially passes through the locking convex tooth 433 and the ratchet convex tooth 432 and then falls into the other locking gap 434, wherein when the ratchet convex tooth 432 falls into the other locking gap 434, the driving convex tooth 8221 impacts against the inner wall of the ratchet groove 431 under the action of the elastic pawl 82 and emits a noise of 'snap' for prompting the completion of the medicine feeding operation. During the entire dispensing operation, the drive element 4 is always locked circumferentially by the locking element 7 and the compression spring 6.

When the medicine injection mechanism is used for injection operation, a user presses the tail cap 9 towards the proximal direction, so that the tail cap 9 is restored to the initial state, and the driving support 5 rotates 720 degrees towards the injection rotation direction due to the matching of the driving protrusion 922 of the tail cap 9 and the driving spiral groove 531 of the driving support 5; the driving bracket 5 drives the ratchet wheel piece 8 to rotate in the ratchet wheel groove 431 towards the injection rotation direction; the drive protrusion 8221 abuts on the ratchet protrusion 432 and pushes the ratchet protrusion 432 to rotate 720 ° in the injection rotation direction, so that the driver 4 and the injection screw 3 rotate 720 ° in the injection rotation direction, so that the injection screw 3 is fed in the proximal direction, and the injection operation is performed.

The above is a preferred embodiment of the present application, and the scope of protection of the present application is not limited by the above, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (9)

1. A medication injection mechanism, characterized by: comprises a tubular shell, an injection screw (3) which is spirally arranged on the tubular shell and can extend into a medicine tube retainer, and an injection driving component for driving the injection screw (3) to axially feed; defining the rotation direction of the injection screw (3) when moving towards the near end as the injection rotation direction, and defining the rotation direction of the injection screw (3) when moving towards the far end as the medicine feeding rotation direction;

the injection driving assembly comprises a driving piece (4) which is sleeved outside the injection screw (3) and used for driving the injection screw (3) to rotate towards the injection rotation direction, a locking piece (7) which is used for limiting the circumferential direction of the driving piece (4) and only can rotate towards the injection rotation direction, a driving support (5) which is circumferentially and rotatably arranged in the tubular shell and axially locked with the tubular shell, and a tail cover (9) which is axially and slidably arranged at the far end of the tubular shell and drives the driving support (5) to rotate; the drive support (5) is provided with ratchet piece (8) at the near-end, ratchet piece (8) have elasticity pawl (82), the distal end of driving piece (4) is arranged and is supplied ratchet dogtooth (432) of elasticity pawl (82) butt joint, drive support (5) have and only can towards injection direction of rotation drive piece (4) synchronous revolution to drive injection screw rod (3) are towards injection direction of rotation is rotated.

2. A medication injection mechanism according to claim 1, wherein: the outer side wall of the distal end part of the driving bracket (5) is axially provided with a driving spiral groove (531), and the tail cover (9) is provided with a driving bulge (922) inserted into the driving spiral groove (531); when the tail cover (9) is pulled out from the initial position towards the far end direction, the tail cover (9) drives the driving bracket (5) to rotate along the medicine feeding rotating direction; when the tail cap (9) is pressed back to the initial position in the proximal direction, the tail cap (9) drives the driving bracket (5) to rotate along the injection rotation direction.

3. A medicament injection mechanism according to claim 2, wherein: the tail cover (9) is provided with a tail end sliding groove (91) which is axially arranged, and the tubular shell is provided with tail end convex teeth (16) which can slide in the tail end sliding groove (91).

4. A medication injection mechanism according to claim 1, wherein: the drive bracket (5) is provided with a bracket clamping disc (52); the tubular shell is provided with a support convex ring (11) in the circumferential direction of the inner wall, a locking cylinder (14) is arranged on the far end face of the support convex ring (11), a first pressing buckle (15) is arranged on the side wall of the locking cylinder (14), and a support gap (154) for the support clamping disc (52) to be arranged is formed between the first pressing buckle (15) and the support convex ring (11).

5. A medication injection mechanism according to claim 1, wherein: the near end of the driving bracket (5) is provided with a bracket mounting column (51), and the outer side wall of the bracket mounting column (51) is provided with a first guide groove (511) along the axial direction; the ratchet wheel piece (8) is sleeved on the outer side of the bracket mounting column (51); the ratchet member (8) has a ratchet guide (811) inserted into the first guide groove (511).

6. A medication injection mechanism according to claim 1, wherein: at least one locking convex strip (17) is axially arranged on the inner wall of the tubular shell, and the locking piece (7) is provided with a locking guide groove (721) for the sliding fit of the locking convex strip (17).

7. A medicament injection mechanism according to claim 6, wherein: the locking element (7) is located on the distal side of the drive element (4), the drive element (4) is provided with a first tooth flank structure (44) on the distal end, and the locking element (7) has a second tooth flank structure (73) which can be engaged with the first tooth flank structure (44); a compression spring (6) is also arranged in the tubular housing, so that the first tooth flank structure (44) always has a meshing engagement with the second tooth flank structure (73).

8. A medication injection mechanism according to claim 1, wherein: the driving piece (4) is provided with a ratchet groove (431) at the far end, and the ratchet convex teeth (432) are arranged on the inner wall of the ratchet groove (431); the ratchet member (8) is disposed within the ratchet groove (431).

9. A medication injection mechanism according to claim 8, wherein: the ratchet groove (431) is provided with a locking convex tooth (433) at one side of the ratchet convex tooth (432) towards the medicine feeding rotation direction; a locking gap (434) arranged at the end of the elastic pawl (82) is formed between the locking convex tooth (433) and the ratchet convex tooth (432).

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