CN115282404A

CN115282404A - Medical injection pen with adjustable dosage

Info

Publication number: CN115282404A
Application number: CN202210982649.2A
Authority: CN
Inventors: 倪世利; 孙小峰; 武玉娟; 汤华振; 温泉
Original assignee: Shandong Weigao Prefills Pharmaceutical Packaging Co Ltd
Current assignee: Shandong Weigao Prefills Pharmaceutical Packaging Co Ltd
Priority date: 2022-08-16
Filing date: 2022-08-16
Publication date: 2022-11-04
Anticipated expiration: 2042-08-16
Also published as: CN115282404B

Abstract

The invention discloses a medical injection pen with adjustable dosage, which comprises a pen container, a medicine bottle rack embedded in the front end of the pen container, a dosage sleeve inserted in the rear end of the pen container, a clutch sleeve fixedly connected in the pen container and positioned in the dosage sleeve, a clutch transmission sleeve in threaded transmission with the clutch sleeve and synchronously rotating with the dosage sleeve, a driving sleeve inserted in the clutch transmission sleeve, a push rod sleeve inserted in the clutch sleeve, a push rod inserted in the push rod sleeve and synchronously rotating with the push rod sleeve, and a transmission nut arranged in the pen container, wherein the clutch transmission sleeve is fixedly connected with the front end of the pen container; the push rod and the transmission nut form thread transmission, and the front end of the push rod is abutted against a rubber plug in the medicament bottle; a sliding groove is formed in the push rod sleeve, and a sliding block matched with the sliding groove is arranged on the driving sleeve; and a clutch mechanism is arranged between the driving sleeve and the clutch transmission sleeve and is used for combining or separating the driving sleeve and the clutch transmission sleeve by pressing. The invention can realize flexible adjustment of injection dosage according to the actual requirement of a patient and simultaneously improve the dosage injection precision.

Description

Medical injection pen with adjustable dosage

Technical Field

The invention relates to the technical field of medical instruments, in particular to a medical injection pen capable of adjusting dosage.

Background

With the development of medical technology, a wide variety of medical instruments have been widely used.

An injection device is a common interventional therapy device, and is mainly used for injecting injection into a human body through organs such as skin. Unlike conventional syringes, the injection device needs to be used with a sealed pre-filled syringe, i.e. to encapsulate and shield the syringe.

At present, the injection device is commonly used in the form of an injection pen, and the injection pen mainly comprises a pen container, a pen cap and the like, wherein the pen container is internally provided with an installation cavity, a medicament bottle such as a cassette bottle and the like can be placed into the installation cavity for fixation, and then an injection button at the rear end of the pen container is pressed, so that the liquid medicament in the medicament bottle can be gradually discharged, and the injection is realized.

However, the content of the medicament in the medicament bottle is fixed, and the medical staff can only inject all the medicament in the medicament bottle at one time in operation, otherwise the medical staff cannot accurately know the actual injection dosage, and in fact, in the face of patients of different ages and different states, the situation that all the medicament in the medicament bottle is not needed or is not suitable to be injected frequently occurs. In the prior art, medical staff usually can only control the injection dosage manually by experience, but the control precision is often insufficient, and the medicine injection control device can only be suitable for patients insensitive to the dosage and cannot be suitable for occasions needing high-precision control of the dosage; or the medicine bottles with corresponding specifications can be installed in the pen container of the injection pen in advance according to the actual dosage requirements of patients, however, the medicine bottles have various specifications, but are graded after all, only aiming at a few common dosage requirements, and cannot cover different dosage requirements in actual occasions.

Therefore, how to achieve flexible adjustment of the injected dose according to the actual needs of the patient, while improving the dose injection accuracy, is a technical problem faced by those skilled in the art.

Disclosure of Invention

The invention aims to provide a medical injection pen with adjustable dose, which can realize flexible adjustment of the injection dose according to the actual requirement of a patient and improve the dose injection precision.

In order to solve the technical problems, the invention provides a medical injection pen with adjustable dosage, which comprises a pen container, a medicine bottle rack embedded at the front end of the pen container and used for containing medicine bottles, a dosage sleeve rotatably inserted into the rear end of the pen container, a clutch sleeve fixedly connected into the pen container and positioned in the dosage sleeve, a clutch transmission sleeve forming thread transmission with the inner wall of the clutch sleeve and rotating synchronously with the dosage sleeve, a driving sleeve rotatably inserted into the clutch transmission sleeve, a push rod sleeve rotatably inserted into the clutch sleeve, a push rod axially slidably inserted into the push rod sleeve and rotating synchronously with the push rod sleeve, and a transmission nut arranged in the pen container;

the outer wall of the push rod and the inner wall of the transmission nut form thread transmission, and the front end of the push rod extends into the medicine bottle rack and is abutted against a rubber plug in the medicine bottle;

a sliding groove is formed in the outer wall of the push rod sleeve along the axial direction, and a sliding block matched with the sliding groove is arranged on the inner wall of the driving sleeve;

and a clutch mechanism is arranged between the rear end of the driving sleeve and the rear end of the clutch transmission sleeve and is used for combining or separating the driving sleeve and the clutch transmission sleeve by pressing.

Preferably, the pen container further comprises an injection button which is embedded at the rear end of the pen container in a pressing mode, and the bottom end of the injection button is abutted to the rear end of the driving sleeve.

Preferably, the rear end of the driving sleeve is provided with a driving ring platform, the rear end of the clutch transmission sleeve is provided with a clutch ring platform, and the clutch mechanism is arranged between the driving ring platform and the clutch ring platform.

Preferably, clutching mechanism includes to erect along the hoop and locates separation and reunion spline on the separation and reunion ring platform, set up in separation and reunion muscle on the drive ring platform, and connect in the separation and reunion ring platform with clutch spring between the drive ring platform to keep through elasticity the separation and reunion muscle breaks away from the separation and reunion spline.

Preferably, the outer wall of the dosage sleeve is provided with dosage scales which are distributed spirally and used for indicating the current target dosage, and the outer wall of the pen container is provided with an observation window used for observing the dosage scales.

Preferably, the cross-sectional shape of the push rod is non-circular, and the cross-sectional shape of the inner installation space of the push rod sleeve is the same as the cross-sectional shape of the push rod.

Preferably, the front end of the push rod sleeve is provided with a ratchet, and the front end of the clutch sleeve is provided with a pawl matched with the ratchet so as to limit the push rod sleeve to rotate in one direction.

Preferably, the pen container further comprises a limiting nut arranged in the pen container and used for limiting the rotation of the transmission nut.

Preferably, the outer wall of the transmission nut is provided with outer limiting teeth, the limiting nut can be axially slidably arranged in the pen container and is used for being abutted to the rear end of the medicament bottle, and the inner wall of the limiting nut is provided with inner limiting teeth matched with the outer limiting teeth.

Preferably, a return spring is arranged between the rear end face of the limit nut and the front end face of the clutch sleeve, so that pretightening force for separating the limit nut from the transmission nut is formed by elasticity.

The invention provides a medical injection pen with adjustable dosage, which mainly comprises a pen container, a medicine bottle rack, a dosage sleeve, a clutch transmission sleeve, a driving sleeve, a push rod, a transmission nut and a clutch mechanism. The pen container is a main body structure of the medical injection pen with the adjustable dosage and is mainly used for installing and containing other parts. The medicine bottle rack is embedded in the inner cavity at the front end of the pen container and is mainly used for containing medicine bottles and realizing the positioning and installation of the medicine bottles in the pen container. The dosing sleeve is inserted in the rear end inner cavity of the pen container, maintains the freedom of rotational movement and can perform clockwise or anticlockwise rotational movement under the screwing operation of hospital personnel. The clutch sleeve is fixedly connected in the pen container, is specifically positioned on the inner side of the dosage sleeve, and is equivalent to the fact that the dosage sleeve is sleeved on the clutch sleeve. The clutch transmission sleeve is arranged on the inner side of the clutch sleeve and forms threaded transmission connection with the inner wall of the clutch sleeve, and meanwhile, the clutch transmission sleeve and the dose sleeve keep synchronous rotary motion. The driving sleeve is inserted inside the clutch transmission sleeve and maintains the freedom of rotational movement. The push rod sleeve is inserted into the clutch sleeve and is positioned at the inner side of the driving sleeve at the same time, and the freedom degree of rotary motion is kept. The outer wall of the push rod sleeve is provided with a sliding groove extending along the axial direction, and the inner wall of the driving sleeve is provided with a sliding block so as to be connected with the push rod sleeve in a sliding manner through the matching of the sliding block and the sliding groove. The push rod is inserted in the push rod sleeve and can slide in the push rod sleeve along the axial direction of the push rod sleeve, and meanwhile, the push rod and the push rod sleeve keep synchronous rotating motion. The transmission nut is arranged in the pen container, the inner wall of the transmission nut and the outer wall of the front end (the part which is not inserted in the push rod sleeve) of the push rod form thread transmission, and the front end of the push rod extends into the medicine bottle rack and is abutted to the rubber plug in the medicine bottle. The clutch mechanism is arranged between the rear end of the driving sleeve and the rear end of the clutch transmission sleeve and is mainly used for realizing the combination or the separation between the clutch transmission sleeve and the driving sleeve through the pressing operation of medical personnel.

Therefore, when the injection dosage is adjusted according to the requirements of a patient, a medical worker can directly screw the dosage sleeve along a preset screwing direction (clockwise or anticlockwise), so as to drive the clutch transmission sleeve to synchronously rotate with the clutch transmission sleeve, the clutch transmission sleeve forms threaded transmission with the clutch sleeve, and the clutch sleeve is a fixing piece, so that the clutch transmission sleeve rotates with the dosage sleeve and axially moves towards the rear end of the pen container. At this moment, clutch mechanism is not pressed, and the clutch driving sleeve does not form the combination with the drive sleeve, therefore, the clutch driving sleeve can only drive the drive sleeve to carry out synchronous axial motion through the butt of its rear end to clutch mechanism, to the rear end of drive sleeve for the slider on the drive sleeve inner wall slides in the spout on push rod sleeve's outer wall. When the dose sleeve is rotated into position, the drive sleeve is also moved axially into position.

When the dose is regulated to a proper position and needs to be injected, a medical worker can directly press the rear end of the driving sleeve to enable the clutch mechanism to be pressed, the clutch transmission sleeve and the driving sleeve are combined into a whole, the driving sleeve is pressed to move axially towards the front end of the pen container, the clutch transmission sleeve performs combined movement of rotation and axial movement through threaded transmission between the clutch transmission sleeve and the clutch transmission sleeve, the dose sleeve and the clutch transmission sleeve perform synchronous combined movement, the clutch transmission sleeve and the driving sleeve are combined into a whole, therefore, when the clutch transmission sleeve performs rotary movement, the driving sleeve also performs rotary movement synchronously, the push rod sleeve is driven to perform synchronous rotary movement through matching of the sliding block and the sliding groove, the push rod is driven to perform synchronous rotary movement, finally, axial sliding of the push rod in the push rod sleeve is achieved through threaded transmission matching between the push rod and the transmission nut, the push rod is gradually screwed out from the push rod sleeve towards the front end of the pen container, and the front end of the syringe needle in the medicine bottle is abutted against the needle head, and medicine in the medicine bottle is gradually extruded, and injection and administration is achieved. When the sliding block on the driving sleeve slides to the end part of the sliding groove on the push rod sleeve, the push rod extends to the limit position, the driving sleeve, the clutch transmission sleeve and the dosage sleeve can not move continuously, and the adjusted expected dosage is injected in the adjusting process.

In conclusion, the medical injection pen with the adjustable dose can realize flexible adjustment of the injection dose according to the actual requirements of patients, and simultaneously improve the dose injection precision.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic overall structure diagram of an embodiment of the present invention.

Fig. 2 is an exploded view of fig. 1.

Fig. 3 is a cross-sectional view of fig. 1.

Fig. 4 is a partial structure diagram of fig. 1.

Fig. 5 is a cross-sectional view of fig. 4.

Fig. 6 shows a detailed construction of the dose sleeve.

Fig. 7 is a specific structure diagram of the clutch transmission sleeve.

Fig. 8 is a schematic view of the connection of the dose sleeve to the clutch driving sleeve.

Fig. 9 is a specific structural diagram of the clutch sleeve.

Fig. 10 is a partial structural schematic diagram of fig. 9.

Fig. 11 is a detailed structural diagram of the driving sleeve.

FIG. 12 is a schematic view of the details of the push rod sleeve.

Fig. 13 is a schematic view of the connection structure of the driving sleeve and the push rod sleeve.

Fig. 14 is a partial structural schematic view of the clutch mechanism.

Fig. 15 is a specific structural diagram of the clutch spring.

Fig. 16 is a schematic view of the structure of the push rod.

Fig. 17 is a schematic view of the structure of the drive nut.

FIG. 18 is a schematic view of the connection structure of the drive nut and the push rod.

Fig. 19 is a schematic view of a specific structure of the limit nut.

FIG. 20 is a schematic view of a structure of the limit nut and the drive nut.

Fig. 21 is a detailed structural diagram of the injection button.

Wherein, in fig. 1-21:

a pen cap-a, a medicament bottle-b, a needle head-c and a rubber plug-d;

the medicine bottle comprises a pen container-1, a medicine bottle rack-2, a dosage sleeve-3, a clutch sleeve-4, a clutch transmission sleeve-5, a driving sleeve-6, a push rod sleeve-7, a push rod-8, a transmission nut-9, an injection button-10, a clutch spring-11, a limit nut-12, a reset spring-13 and a pressing insert-14;

observation window-101, dose scale-31, knob-32, draw-in groove-33, pawl-41, internal thread-42, clutch ring platform-51, clutch spline-52, external thread-53, clamping block-54, slide block-61, drive ring platform-62, clutch rib-63, sliding groove-71, ratchet-72, special-shaped groove-73, turnbuckle-81, external limit tooth-91 and internal limit tooth-121.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 2, fig. 3, fig. 4, and fig. 5, fig. 1 is a schematic overall structure diagram of an embodiment of the present invention, fig. 2 is an exploded view of fig. 1, fig. 3 is a cross-sectional view of fig. 1, fig. 4 is a schematic partial structure diagram of fig. 1, and fig. 5 is a cross-sectional view of fig. 4.

In one embodiment of the present invention, the medical injection pen with adjustable dose mainly comprises a pen container 1, a medicine bottle holder 2, a dose sleeve 3, a clutch sleeve 4, a clutch transmission sleeve 5, a driving sleeve 6, a push rod sleeve 7, a push rod 8, a transmission nut 9 and a clutch mechanism.

The pen container 1 is a main body structure of the medical injection pen with the adjustable dosage and is mainly used for installing and containing other parts. Generally, the inner installation space of the pen container 1 can be divided into two parts, namely a front end inner cavity and a rear end inner cavity. Of course, a cap a may be further provided on the front end portion of the barrel 1 for closing and protecting.

The medicine bottle rack 2 is embedded in the inner cavity at the front end of the pen container 1 and is mainly used for containing the medicine bottles b and realizing the positioning and installation of the medicine bottles b in the pen container 1. Generally, the medicine bottle holder 2 can be regarded as a front section part of the pen container 1, and can be detachably connected with a rear section part of the pen container 1 through a clamping structure.

Fig. 6 is a detailed schematic view of the dose sleeve 3, as shown in fig. 6.

The dosing sleeve 3 is inserted in the rear end cavity of the barrel 1 and maintains the freedom of rotational movement, being able to perform a clockwise or anticlockwise rotational movement under the screwing operation of the hospital personnel. Generally, the dose adjustment value increases upon rotational movement of the dose sleeve 3 towards the rear end of the barrel 1, and decreases otherwise.

As shown in fig. 9, fig. 9 is a specific structural diagram of the clutch sleeve 4.

The clutch sleeve 4 is fixedly connected in the pen container 1, is specifically positioned on the inner side of the dosage sleeve 3, and is equivalent to the dosage sleeve 3 sleeved on the clutch sleeve 4.

As shown in fig. 7, fig. 7 is a specific structural schematic diagram of the clutch transmission sleeve 5.

The clutch driving sleeve 5 is mounted inside the clutch sleeve 4 and forms a threaded driving connection with the inner wall of the clutch sleeve 4, while the clutch driving sleeve 5 also maintains a synchronous rotational movement with the dose sleeve 3. Generally, in order to facilitate the clutch transmission sleeve 5 and the clutch sleeve 4 to form a thread transmission, an internal thread 42 is formed on the inner wall of the clutch sleeve 4, and an external thread 53 is formed on the outer wall of the clutch transmission sleeve 5, so that the thread transmission is realized by the matching of the internal thread 42 and the external thread 53.

As shown in fig. 11, fig. 11 is a specific structural diagram of the driving sleeve 6.

The drive sleeve 6 is inserted inside the clutch transmission sleeve 5 and maintains the freedom of rotational movement.

As shown in fig. 12 and 13, fig. 12 is a schematic view showing a specific structure of the push rod sleeve 7, and fig. 13 is a schematic view showing a connection structure of the drive sleeve 6 and the push rod sleeve 7.

The push rod sleeve 7 is inserted in the clutch sleeve 4 and at the same time is located inside the drive sleeve 6 and maintains the freedom of rotational movement. The outer wall of the push rod sleeve 7 is provided with a sliding groove 71 extending along the axial direction, and the inner wall of the driving sleeve 6 is provided with a sliding block 61, so that the push rod sleeve 7 and the driving sleeve 6 are slidably connected through the matching of the sliding block 61 and the sliding groove 71.

As shown in fig. 16, fig. 16 is a schematic structural diagram of the push rod 8.

The push rod 8 is inserted into the push rod sleeve 7 and can slide in the push rod sleeve 7 in the axial direction thereof, while the push rod 8 and the push rod sleeve 7 maintain a synchronous rotational movement.

As shown in fig. 17 and 18, fig. 17 is a detailed structural schematic view of the driving nut 9, and fig. 18 is a structural schematic view of the driving nut 9 and the push rod 8 connected together.

The transmission nut 9 is arranged in the pen container 1, the inner wall of the transmission nut 9 and the outer wall of the front end (the part which is not inserted in the push rod sleeve 7) of the push rod 8 form thread transmission, and the front end of the push rod 8 extends into the medicine bottle rack 2 all the time and forms butt joint with a rubber plug d in the medicine bottle b.

The clutch mechanism is arranged between the rear end of the driving sleeve 6 and the rear end of the clutch transmission sleeve 5 and is mainly used for realizing the combination or the separation between the clutch transmission sleeve 5 and the driving sleeve 6 through the pressing operation of medical personnel.

Thus, when the injection dosage is adjusted according to the requirements of a patient, a medical worker can directly screw the dosage sleeve 3 along a preset screwing direction (clockwise or anticlockwise), so as to drive the clutch transmission sleeve 5 to synchronously rotate with the dosage sleeve, the clutch transmission sleeve 5 forms threaded transmission with the clutch sleeve 4, and the clutch sleeve 4 is a fixing piece, so that the clutch transmission sleeve 5 rotates with the dosage sleeve 3 and axially moves towards the rear end of the pen container 1. At this time, the clutch mechanism is not pressed, and the clutch transmission sleeve 5 is not coupled to the driving sleeve 6, so that the clutch transmission sleeve 5 can drive the driving sleeve 6 to perform synchronous axial movement only by abutting the rear end of the clutch mechanism against the rear end of the driving sleeve 6, so that the sliding block 61 on the inner wall of the driving sleeve 6 slides in the sliding groove 71 on the outer wall of the push rod sleeve 7. When the dose sleeve 3 is rotated into position, the drive sleeve 6 is also moved axially into position.

When the dosage is adjusted to the right position and needs to be injected, a medical worker can directly press the rear end of the driving sleeve 6 to press the clutch mechanism, so that the clutch transmission sleeve 5 and the driving sleeve 6 are combined into a whole, the driving sleeve 6 is pressed to move axially towards the front end of the pen container 1, the clutch transmission sleeve 5 performs combined movement of rotation and axial movement through threaded transmission between the clutch transmission sleeve 5 and the clutch transmission sleeve 4, the dosage sleeve 3 and the clutch transmission sleeve 5 perform synchronous combined movement, at the moment, the clutch transmission sleeve 5 and the driving sleeve 6 are combined into a whole, therefore, when the clutch transmission sleeve 5 performs rotary movement, the driving sleeve 6 also performs synchronous rotary movement, the push rod sleeve 7 is driven to perform synchronous rotary movement through the matching of the sliding block 61 and the sliding groove 71, the push rod 8 is driven to perform synchronous rotary movement, finally, the axial sliding of the push rod 8 in the push rod sleeve 7 is realized through the threaded transmission matching between the push rod 8 and the transmission nut 9, the push rod 8 is gradually screwed out from the front end of the push rod sleeve 7 towards the front end of the pen container 1, the front end of the push rod 8 and the medicine bottle d in the medicine bottle b in the pen container b is gradually pushed out, and the medicine bottle c is gradually pushed out from the medicine bottle c in the syringe barrel. When the slider 61 on the drive sleeve 6 slides to the end of the slide groove 71 on the push rod sleeve 7, the push rod 8 extends to the extreme position, and the drive sleeve 6, the clutch transmission sleeve 5 and the dose sleeve 3 cannot move any further, and the desired dose adjusted in the adjustment process is injected.

In conclusion, the medical injection pen with adjustable dose provided by the embodiment can realize flexible adjustment of injection dose according to the actual demand of a patient, and meanwhile, the dose injection precision is improved.

As shown in fig. 21, fig. 21 is a detailed structural diagram of the injection button 10.

Considering that when the medical staff injects, the rear end of the driving sleeve 6 needs to be continuously pressed to ensure that the clutch mechanism is always in a pressing state, that is, the driving sleeve 6 and the clutch transmission sleeve 5 are always in a combined state, for this reason, the injection button 10 is additionally arranged in the embodiment. Specifically, the injection button 10 is embedded in the rear end face of the pen barrel 1, and the bottom end (inner end) of the injection button 10 is abutted against the rear end of the driving sleeve 6. So configured, the medical staff can press the injection button 10 only, and the rear end of the drive sleeve 6 is pressed by the injection button 10.

Furthermore, considering that the rear end of the driving sleeve 6 is cylindrical and generally hollow, in order to achieve stable contact between the injection button 10 and the driving sleeve 6, a pressing insert 14 is additionally provided in the present embodiment. Specifically, the pressing insert 14 is embedded in the rear end of the driving sleeve 6, is integrally disc-shaped, and has a protruding column vertically arranged on the end surface facing the injection button 10 and forms positioning fit with the groove at the bottom end of the injection button 10. With such an arrangement, when the medical staff presses the injection button 10, the pressing force can be smoothly transmitted to the rear end of the drive sleeve 6 through the pressing insert 14.

In order to facilitate the screwing operation of the dose sleeve 3 by the medical staff, the present embodiment is provided with a knob 32 at the rear end of the dose sleeve 3.

Fig. 8 is a schematic view of the connection of the dose sleeve 3 to the clutch transmission sleeve 5, as shown in fig. 8.

Further, in order to ensure the synchronous rotation motion between the dose sleeve 3 and the clutch transmission sleeve 5, in this embodiment, a clamping groove 33 is formed on the inner edge of the rear end of the dose sleeve 3, and a clamping block 54 is also arranged on the outer wall of the rear end of the clutch transmission sleeve 5 to form clamping fit with the clamping groove 33 through the clamping block 54, so that the dose sleeve 3 and the clutch transmission sleeve 5 are connected into a whole, and the synchronous rotation motion of the dose sleeve 3 and the clutch transmission sleeve 5 is ensured.

In order to realize the stable installation of the clutch mechanism between the driving sleeve 6 and the clutch transmission sleeve 5, in this embodiment, a driving ring platform 62 is disposed at the rear end of the driving sleeve 6 along the circumferential direction, and meanwhile, a clutch ring platform 51 is disposed at the rear end of the clutch transmission sleeve 5 along the circumferential direction, and the clutch mechanism is disposed between the driving ring platform 62 and the clutch ring platform 51 which are opposite to each other in the axial direction. Generally, the rear end of the driving sleeve 6 is located outside the rear end of the clutch transmission sleeve 5 and closer to the rear end of the pen container 1, and is configured such that the front end of the clutch mechanism is connected to the end face of the clutch collar 51, and the rear end of the clutch mechanism is connected to the end face of the driving collar 62.

As shown in fig. 14, fig. 14 is a partial structural schematic diagram of the clutch mechanism.

In an alternative embodiment with respect to the clutch mechanism, the clutch mechanism mainly includes the clutch spline 52, the clutch rib 63, and the clutch spring 11.

The clutch spline 52 is annularly erected on the clutch collar 51, and is distributed along the circumferential direction of the clutch collar 51. Meanwhile, a plurality of key grooves are formed in the end face, facing the driving ring table 62, of the clutch spline 52 in the circumferential direction, so that a spline structure is formed.

The clutch rib 63 is provided on the end surface of the drive ring table 62, and protrudes from the end surface of the drive ring table 62 toward the clutch spline 52 on the clutch ring table 51. The clutch rib 63 can be engaged with any one of the key grooves of the clutch spline 52.

As shown in fig. 15, fig. 15 is a specific structural schematic diagram of the clutch spring 11.

The clutch spring 11 is arranged between the opposite end faces of the clutch annular table 51 and the driving annular table 62, the elastic direction of the clutch spring is axial, and the two ends of the clutch spring are respectively connected with the opposite end faces of the clutch annular table 51 and the driving annular table 62. In a natural state, the elastic force of the clutch spring 11 can ensure that the clutch ring 51 and the driving ring 62 are away from each other, and the clutch rib 63 is disengaged from the clutch spline 52, i.e. the driving sleeve 6 and the clutch transmission sleeve 5 are kept in an uncombined state. When the rear end of the driving sleeve 6 is pressed, the clutch spring 11 is compressed, the clutch rib 63 on the driving sleeve 6 is matched with the clutch spline 52 on the clutch transmission sleeve 5, and the driving sleeve 6 and the clutch transmission sleeve 5 are integrated.

In order to facilitate the medical staff to intuitively understand the current dosage adjustment degree, a dosage scale 31 and an observation window 101 are added in the embodiment. Wherein, the dose scale 31 is provided on the outer wall of the dose sleeve 3 and is spirally distributed on the outer wall of the dose sleeve 3, mainly for indicating the current target dose. For example, the dosage scale 31 is gradually distributed from 0ml to 30ml along a spiral shape, namely 0ml, 2ml, 4ml \8230; 8230; 30ml to the maximum dosage. Meanwhile, the outer wall of the pen container 1 is provided with an observation window 101. Specifically, the opening position of the observation window 101 corresponds to the position of the dose scale 31 provided on the dose sleeve 3, and when the dose sleeve 3 rotates, the dose sleeve 3 performs a combined movement of a rotational movement and an axial movement, that is, the dose sleeve 3 moves spirally, and the dose scales 31 are distributed spirally on the dose sleeve 3, so that the change of the dose scale 31 can be observed at the observation window 101 all the time, and the medical staff can determine the current target dose.

In a rotatable embodiment of the push rod 8, in order to ensure that the push rod 8 can keep rotating synchronously with the push rod sleeve 7 when the push rod moves rotationally, in the embodiment, the cross section of the push rod 8 is non-circular, such as circular with cut edges, or rectangular, which can also be adopted. Correspondingly, a special-shaped groove 73 is formed in the push rod sleeve 7, the push rod 8 is slidably inserted into the special-shaped groove 73, and the cross-sectional shape of the special-shaped groove 73 is non-circular and is consistent with the cross-sectional shape of the push rod 8. So set up, push rod 8 can carry out the axial sliding motion smoothly in push rod sleeve 7, simultaneously, when push rod sleeve 7 is rotatory, can drive push rod 8 and carry out synchronous rotary motion.

Of course, in order to form the screw transmission between the push rod 8 and the transmission nut 9, an external thread is formed on the outer wall of the push rod 8, and an internal thread is formed on the inner wall of the transmission nut 9.

As shown in fig. 10, fig. 10 is a partial structural schematic diagram of fig. 9.

Furthermore, in order to improve the precision of medicament injection as much as possible and prevent the push rod 8 from being accidentally reversed during the injection process, the present embodiment is provided with the ratchet 72 and the pawl 41. The ratchet teeth 72 are disposed at the front end of the push rod sleeve 7, and are generally in a ring structure, and each ratchet tooth 72 is circumferentially distributed at the front end of the push rod sleeve 7 and has a single directional orientation. The pawl 41 is arranged at the front end of the clutch sleeve 4 and is mainly used for being matched with the ratchet 72 so as to limit the unidirectional rotation of the push rod sleeve 7 by utilizing the unidirectional transmission characteristic of the ratchet transmission mechanism and prevent the push rod sleeve 7 from reversing in the injection process, thereby ensuring that the push rod 8 can only be gradually screwed out of the push rod sleeve 7 and cannot be screwed into the push rod sleeve 7.

Moreover, in order to facilitate the pushing of the push rod 8 to the rubber plug d in the medicine bottle b, the rotating buckle 81 is additionally arranged in the embodiment. Specifically, this turn-buckle 81 sets up the front end at push rod 8 to carry out synchronous rotation and axial concertina movement with push rod 8, simultaneously, turn-buckle 81's terminal surface and plug d's terminal surface butt each other, thereby when push rod 8 back-out, turn-buckle 81 can directly promote plug d in step and slide in medicament bottle b, and then extrude medicament from syringe needle c department.

As shown in fig. 19, fig. 19 is a specific structural schematic diagram of the limit nut 12.

In addition, considering that the driving nut 9 must not rotate synchronously with the push rod 8 when the driving nut 9 and the push rod 8 form a thread transmission, the limit nut 12 is added in the embodiment. The limit nut 12 is disposed in the pen container 1, and is generally located in a front end region of the pen container 1, and is mainly used for limiting the rotational freedom of the drive nut 9 and preventing the drive nut 9 and the push rod 8 from rotating synchronously.

As shown in FIG. 20, FIG. 20 is a schematic view of the structure of the lock nut 12 and the drive nut 9

Specifically, the limit nut 12 can axially slide in the pen container 1, the front end face of the limit nut 12 faces the rear end face of the medicine bottle rack 2, and when the medicine bottles b are mounted on the medicine bottle rack 2, the rear end face of the medicine bottles b abuts against the front end face of the limit nut 12, and the rear end face of the limit nut 12 is pressed onto the front end face of the clutch sleeve 4. Meanwhile, the outer wall of the transmission nut 9 is provided with outer limiting teeth 91, the inner wall of the limiting nut 12 is provided with inner limiting teeth 121, and when the limiting nut 12 is pressed in place by the medicament bottle b, the inner limiting teeth 121 on the limiting nut 12 are meshed with the outer limiting teeth 91 on the transmission nut 9, so that the transmission nut 9 is limited to rotate.

Further, in this embodiment, a return spring 13 is additionally provided between the rear end surface of the limit nut 12 and the front end surface of the clutch sleeve 4. Specifically, the direction of the elastic force of the return spring 13 is the axial direction of the pen container 1, and is mainly used for forming a pre-tightening force for disengaging the transmission nut 9 on the limit nut 12 through the elastic force, so that after the injection is completed and the medicament bottle b is taken down, the limit nut 12 axially slides to the reset position through the elastic force, and the inner limit teeth 121 are disengaged from the outer limit teeth 91.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The medical injection pen with the adjustable dosage is characterized by comprising a pen container (1), a medicine bottle rack (2) which is embedded at the front end of the pen container (1) and used for containing medicine bottles, a dosage sleeve (3) which is rotatably inserted into the rear end of the pen container (1), a clutch sleeve (4) which is fixedly connected into the pen container (1) and is positioned in the dosage sleeve (3), a clutch transmission sleeve (5) which forms thread transmission with the inner wall of the clutch sleeve (4) and synchronously rotates with the dosage sleeve (3), a driving sleeve (6) which is rotatably inserted into the clutch transmission sleeve (5), a push rod sleeve (7) which is rotatably inserted into the clutch sleeve (4), a push rod (8) which is axially slidably inserted into the push rod sleeve (7) and synchronously rotates with the push rod sleeve, and a transmission nut (9) which is arranged in the pen container (1);

the outer wall of the push rod (8) and the inner wall of the transmission nut (9) form thread transmission, and the front end of the push rod (8) extends into the medicine bottle rack (2) and is abutted against a rubber plug in the medicine bottle;

a sliding groove (71) is formed in the outer wall of the push rod sleeve (7) along the axial direction, and a sliding block (61) matched with the sliding groove (71) is arranged on the inner wall of the driving sleeve (6);

and a clutch mechanism is arranged between the rear end of the driving sleeve (6) and the rear end of the clutch transmission sleeve (5) and is used for combining or separating the driving sleeve and the clutch transmission sleeve by pressing.

2. The adjustable dose medical injection pen according to claim 1, further comprising an injection button (10) pressably fitted in the rear end of the pen barrel (1), the bottom end of the injection button (10) abutting the rear end of the drive sleeve (6).

3. The adjustable dose medical injection pen according to claim 1, wherein the rear end of the drive sleeve (6) is provided with a drive collar (62), the rear end of the clutch transmission sleeve (5) is provided with a clutch collar (51), and the clutch mechanism is arranged between the drive collar (62) and the clutch collar (51).

4. The adjustable dose medical injection pen according to claim 3, wherein the clutch mechanism comprises a clutch spline (52) standing on the clutch ring platform (51) in a circumferential direction, a clutch rib (63) provided on the driving ring platform (62), and a clutch spring (11) connected between the clutch ring platform (51) and the driving ring platform (62) to keep the clutch rib (63) disengaged from the clutch spline (52) by an elastic force.

5. The adjustable dose medical injection pen according to claim 1, wherein the outer wall of the dose sleeve (3) is provided with dose scales (31) which are spirally distributed and used for indicating the current target dose, and the outer wall of the pen barrel (1) is provided with an observation window (101) used for observing the dose scales (31).

6. The adjustable dose medical injection pen according to claim 1, wherein the cross-sectional shape of the plunger (8) is non-circular and the cross-sectional shape of the inner mounting space of the plunger sleeve (7) is the same as the cross-sectional shape of the plunger (8).

7. The adjustable dose medical injection pen according to claim 6, wherein the front end of the push rod sleeve (7) is provided with ratchet teeth (72), and the front end of the clutch sleeve (4) is provided with a pawl (41) for cooperating with the ratchet teeth (72) to restrict the push rod sleeve (7) from rotating in one direction.

8. The adjustable dose medical injection pen according to claim 1, further comprising a limit nut (12) disposed in the pen barrel (1) for limiting the rotation of the drive nut (9).

9. The adjustable dose medical injection pen according to claim 8, wherein the outer wall of the drive nut (9) is provided with outer limit teeth (91), the limit nut (12) is axially slidably arranged in the pen container (1) and is used for abutting against the rear end of a medicament bottle, and the inner wall of the limit nut (12) is provided with inner limit teeth (121) used for matching with the outer limit teeth (91).

10. The medical injection pen with adjustable dose according to claim 9, wherein a return spring (13) is arranged between the rear end face of the stop nut (12) and the front end face of the clutch sleeve (4) to form a pre-tightening force for disengaging the drive nut (9) to the stop nut (12) by an elastic force.