CN110841149A

CN110841149A - Low-temperature locking automatic injector

Info

Publication number: CN110841149A
Application number: CN201911310001.5A
Authority: CN
Inventors: 熊长艳; 陈红丹
Original assignee: Suzhou Jiashu Medical Technology Co Ltd
Current assignee: Suzhou Jiashu Medical Technology Co Ltd
Priority date: 2019-12-18
Filing date: 2019-12-18
Publication date: 2020-02-28
Also published as: WO2021120824A1

Abstract

The invention provides a low-temperature locking automatic injector which is characterized by comprising an injector body, a pen cap and a memory material locking piece, wherein the injector body is provided with an open end, the open end is sleeved with the pen cap, the injector body is used for accommodating a pre-filled syringe, a needle head of the pre-filled syringe is positioned in a space formed by the injector body and the pen cap, and the pen cap and the injector body are locked at a low temperature and unlocked at a high temperature through the memory material locking piece.

Description

Low-temperature locking automatic injector

Technical Field

The invention relates to the field of medical instruments, in particular to low-temperature locking automatic injection equipment.

Background

Most of the existing automatic injectors are stored at about 5 ℃ to ensure the drug effect. Autoinjectors generally require 30 minutes or more at room temperature prior to injection, which has the following benefits:

1. the pain during injection can be greatly reduced by injecting at room temperature;

2. the auto-injector is designed according to the drug viscosity at room temperature, and if injected at low temperature, the auto-injector may not work or the injected dose is inaccurate;

3. the drug effect is also most effective at room temperature.

With all automatic injectors on the market today, the user can inject at low temperatures.

CN110237366A discloses a medical injection device, which comprises an outer barrel and a pen cap, one end of the outer barrel is provided with a detachable medicine bin, a replaceable standard card type medicine bottle is arranged in the medicine bin, one end of the inner part of the outer barrel close to the medicine bin is provided with a fixed sleeve, the inner axial movement of the fixed sleeve is provided with a push rod seat, the inner part of the push rod seat is provided with a transmission ring which can be meshed with the end part of a transmission rod, the outer side of the transmission rod is sleeved with a ratchet ring which can axially slide, one end face of the ratchet ring is in one-way meshing with the inner part of the outer barrel, the other end of the ratchet ring is axially provided with a first spring, one end of the push rod seat is axially provided with a push rod seat spring which is propped against the outer barrel.

CN109999272A discloses a disposable adjustable injection device for insulin injection, which comprises a protective cover, a disposable needle, a pen core sleeve, a main body shell, a pen core and an adjusting component, one end of the main body shell is provided with a second boss, the outside of the second boss is provided with a refill sleeve, one end of the pencil lead sleeve is provided with a thread groove, the external thread of the second boss is in threaded connection with the thread groove, the other end of the refill sleeve is provided with a first boss, the outside of the first boss is connected with a disposable needle head through threads, a steel needle is inserted in the disposable needle head, a pen core is arranged in the pen core sleeve, a protective cover is sleeved outside the pen core sleeve, the other end of main body cover is provided with adjusting part, main body cover's internally mounted has fixed sleeve, fixed sleeve's one end outside protrusion has flange portion.

CN102264417A discloses an injection device comprising: a long housing; a container carrier having a medicament container to which a needle is mounted; a puncture device comprising a separation sleeve, a preloaded puncture spring device and a puncture holding device, wherein said preloaded puncture spring device is capable of acting on said separation sleeve and thereby on said container carrier for a sliding movement of said container and needle, and said puncture holding device is capable of holding said puncture spring device in a loaded state; injection means comprising a plunger rod, pre-loaded injection spring means and injection retaining means, wherein the plunger rod is arranged to act on a stopper in the medicament container, the pre-loaded injection spring means is adapted to act on the plunger rod such that the stopper is displaced within the container, and the injection retaining means is adapted to retain the injection spring means in a loaded state; retraction means comprising a preloaded retraction spring and retraction holding means, wherein the preloaded retraction spring is arranged to act on the separation sleeve and thereby on the container carrier, and the retraction holding means is capable of holding the retraction spring in a loaded state; a puncture sequence initiating means capable of acting on a puncture trigger means arranged on said separation cannula for disconnecting said puncture holding means; an injection trigger means provided on said separation sleeve and capable of disconnecting said injection holding means to initiate an injection sequence when the separation sleeve and the plunger rod are moved to a specific position; and retraction triggering means arranged on said separation sleeve and capable of disconnecting said retraction holding means for initiating needle retraction when said plunger rod has been moved to a certain position; characterized in that the device further comprises damping means comprising a compartment containing a volume of a highly viscous liquid and being partly defined by the outer surface of the plunger rod and the inner surface of the cap, wherein the compartment is arranged with a channel through which the liquid is forced only upon initiation of the injection sequence, such that the volume within the compartment decreases with movement of the plunger rod in the container during the entire injection sequence and thereby damping shear forces are generated.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the prior art and provide the temperature-controlled automatic injector, and the scheme of the invention can ensure that the automatic injector can inject only when the temperature is higher than a certain temperature, and the automatic injector is in a locking state at low temperature, thereby avoiding a series of defects caused by improper operation of a user during injection at low temperature.

In order to achieve the above object, the present invention provides:

a cryo-locked auto-injector comprising an injector body, a pen cap and a memory material locking element, said injector body having an open end, said open end being in socket connection with said pen cap, said injector body accommodating a pre-filled syringe, a needle of said pre-filled syringe being located in a space formed by the injector body and the pen cap, said pen cap and said injector body being locked at a low temperature and unlocked at a high temperature by said memory material locking element;

the low temperature may be selected according to the storage requirements of the drug, e.g. any temperature of 0-6 degrees, and the high temperature may be selected according to the injection requirements of the drug, e.g. any temperature of 10-25 degrees;

the memory material locking member can lock the pen cap and the pen shell at low temperature in various ways, and is not limited herein.

Preferably, the open end of syringe body has first recess, the pen cap has the second recess, works as the pen cap with when the syringe body cup joints, the recess that is located on outer part is for running through the groove, and two recesses on the above-mentioned part overlap in the position, and two cell bodies form a degree of depth after overlapping and be the cell body that both sum. The inner and outer relationship between the pen cap and the injector body when they are connected is not limited here.

Preferably, when the pen cap and the injector body are sleeved, the memory material locking piece has a martensite shape at low temperature, and in the shape, the memory material locking piece is clamped into the grooves of the pen cap and the injector body, keeps the shape and cannot be taken out, and locks the pen cap and the injector body. As for the shape of martensite, there is no particular limitation as long as the shape in which the memory material locking member has a degree of freedom greater than the depth of the groove formed by the first groove and the second groove can be taken out from the above-mentioned groove, for example, when the socket part is a cylinder, the memory material locking member is a ring having a radius (inner diameter) greater than the radius of the socket part.

The memory material locking piece is transformed into an austenite shape at high temperature, and in the shape, the memory material locking piece is separated from the grooves of the pen cap and the injector body and unlocks the pen cap and the injector body. As for the shape of austenite, no particular limitation is imposed as long as the shape is such that the memory material locking member has a degree of freedom smaller than the depth of the groove formed by the first groove and the second groove and cannot be taken out from the groove, for example, when the socket part is a cylinder, the memory material locking member is an ellipse whose short radius (inner diameter) is smaller than the radius of the socket part, or a standard rectangle whose short side (inner diameter) is smaller than the radius of the socket part, or a rectangle having four corners in the shape of an arc.

Preferably, the memory material is a memory alloy.

Preferably, the memory alloy is selected from nickel-titanium alloy, copper-zinc alloy, copper-aluminum-nickel alloy, copper-molybdenum-nickel alloy and copper-gold-zinc alloy.

According to the technical scheme, the automatic injector can inject only when the temperature of the automatic injector is higher than a certain temperature, and the pen cap and the injector body cannot be separated below the certain temperature, so that the injection cannot be performed, and a series of defects caused by injection at a low temperature due to improper operation of a user are avoided.

On the other hand, the invention also provides a disposable automatic injector which has simple structure, obviously reduced number of parts and high reliability of each injection step.

Preferably, the injection assembly comprises a propelling assembly, a starting assembly and a triggering assembly, the propelling assembly is positioned in the starting assembly, the propelling assembly comprises a propelling part and a limiting part, the propelling part is clamped with the limiting part to realize limiting, and the starting assembly ensures the braking of the propelling assembly before injection by fixing the limiting form of the propelling assembly;

the trigger assembly receives the pre-filled syringe and, after an injection is initiated, pushes the actuation assembly out of the braking position.

Preferably, the propelling part of the propelling assembly comprises a main spring sleeve and a main spring, the limiting part of the propelling part comprises a main shaft, and the starting assembly comprises a starting sliding sleeve and an auxiliary spring;

the spindle body of the spindle is hollow, one end of the spindle body is closed and is provided with a first flange, a plurality of first bumps and second bumps with elasticity are respectively arranged on the spindle body from near to far away from the first flange, the first bumps protrude towards the outer surface direction of the spindle body, the first bumps are provided with axial guide slopes towards the first flange direction, the second bumps protrude towards the inner surface direction of the spindle body, and the second bumps are provided with axial guide slopes towards the first flange direction;

the main spring sleeve is positioned in the spindle shaft body, one end of the main spring sleeve is closed, the other end of the main spring sleeve is open, the closed end can be inserted into the pre-filled syringe, a clamping groove matched with the second bump is formed in the sleeve body of the main spring sleeve, one end of the pre-tightened main spring abuts against the closed end of the main spring sleeve, the other end of the pre-tightened main spring abuts against the closed end of the spindle, and the second bump is clamped into the clamping groove;

the starting sliding sleeve is sleeved outside the main shaft, the far end of the starting sliding sleeve is provided with a second flange, the inner surface of the sliding sleeve is axially provided with a third groove capable of accommodating the first lug to slide in the third groove, one end of the third groove is opened, the other end of the third groove is closed, the opening is positioned at the flange end of the sliding sleeve, the first lug and the second lug are completely positioned inside the starting sliding sleeve, an auxiliary spring is arranged between the first flange and the second flange, and the first lug is clamped at the closed end of the third groove;

after the clamping groove of the main spring sleeve is clamped with the second convex block of the main shaft body, the sleeve body of the starting sliding sleeve tightly presses the second convex block, so that the second convex block of the main shaft body and the clamping groove of the main spring sleeve are clamped, and the starting assembly is reliably fixed in a locking state.

Preferably, the trigger assembly comprises a syringe slide;

the syringe sliding sleeve can enable the pre-filled syringe to freely slide in the sleeve, a plurality of grooves are formed in the sleeve body, one end of the syringe sliding sleeve props against the starting sliding sleeve, the other end of the syringe sliding sleeve is provided with a first groove of the injector body, and the length of the syringe sliding sleeve exceeds the length of a needle head of the pre-filled syringe;

preferably, the housing is sleeved outside the automatic injector, one end of the housing is fixed on the first flange, the other end of the housing is shorter than the needle head of the pre-filled syringe, and a plurality of clamping blocks are arranged inside the housing and can clamp the flange of the pre-filled syringe through the through groove of the syringe sliding sleeve, so that the pre-filled syringe cannot move towards the injection direction. The length of the other end of the shell, which is shorter than the needle head, determines the puncture depth;

preferably, the part of the shaft body wall where the first and second bumps are located is hollowed out to form an elastic strip;

preferably, when the elastic strips of the first and second protrusions are positioned on a straight line, the width of the strip of the second protrusion is greater than that of the third groove in the starting sliding sleeve, so that the strip of the second protrusion is not wholly positioned in the space of the third groove, and the inner wall of the starting sliding sleeve can be ensured to tightly press the second protrusion;

preferably, the closed end of the main spring housing is provided with a hole, so that air between the main spring housing and the piston of the pre-filled syringe can be discharged in time, and the main spring housing is in quick and unobstructed contact with the piston after the injection is started;

preferably, the housing and the first flange are fixed by snapping;

preferably, the shaft body of the main shaft is further provided with a plurality of third elastic lugs protruding towards the outer surface of the shaft body, and the distance from the first flange is greater than the distance from the first lug to the second lug. The third bump is used for facilitating assembly, and temporarily fixing the starting sliding sleeve and the auxiliary spring on the main shaft before the main spring sleeve and the main spring are assembled on the main shaft;

preferably, one end of the syringe sliding sleeve, which is propped against the starting sliding sleeve, is provided with an inward convex barb.

Preferably, a pre-filled syringe is included.

The invention also provides a method for injecting by using the injector, which is characterized by comprising the following specific steps:

the method comprises the following steps: the starting stage, taking out the injector from the low-temperature state, placing the injector in the high-temperature state, pulling out the pen cap until the injector is unlocked, placing the sliding sleeve end of the needle cylinder on the skin to be injected, and pressing down;

step two: in the puncture stage, the needle cylinder sliding sleeve pushes the starting sliding sleeve to move upwards relative to the needle head until the needle head contacts the skin, pressure is continuously applied, the needle head starts to puncture the skin, the needle head sliding sleeve pushes the starting sliding sleeve to move upwards until the needle head sliding sleeve completely enters the shell, the preset subcutaneous puncture depth is reached at the moment, and the puncture is finished; in the puncture process, the lower end of the starting sliding sleeve moves to the position above the second bump, the locking state of the second bump and the clamping groove is released, under the thrust action of the main spring, the clamping groove of the main spring sleeve slides along the axial guide slope of the second bump, the second bump elastically deforms outwards until the clamping groove completely leaves the clamping position of the second bump, the main spring pushes the main spring sleeve to continue to move forwards, and the front part of the main spring sleeve contacts and supports against the piston of the prefilled syringe;

step three: in the injection stage, the pre-filled syringe and the shell are fixedly clamped, the main spring continues to push the main spring sleeve and the piston, and the medicine in the pre-filled syringe is injected to the subcutaneous part of the patient until the piston reaches the bottommost end of the syringe, and the injection is finished;

step four: and in the resetting stage, the automatic injector is moved away, the auxiliary spring pushes the needle head sliding sleeve and the starting sliding sleeve to return, when the upper end of the starting sliding sleeve contacts the first bump, the upper end of the starting sliding sleeve slides along the axial guide slope surface of the first bump, the first bump elastically deforms inwards and then is separated from the starting sliding sleeve until the barb of the syringe sliding sleeve blocks the flange of the pre-filled syringe, and the injection procedure is finished. At the moment, the first bump is already separated from the starting sliding sleeve and is sealed in the shell, and the first bump cannot reversely enter the starting sliding sleeve again because of no guiding slope surface, so that the whole injection process is blocked if an injector repeats the step I, and the reuse of the automatic injector is avoided.

Compared with the prior art, the invention has the following beneficial effects:

1. the automatic injector can be ensured to inject only when the temperature is higher than a certain temperature, and the pen cap and the shell can not be separated when the temperature is lower than the certain temperature, so that injection can not be carried out, and a series of defects caused by improper operation of a user during injection at low temperature are avoided;

2. the injector is designed into a propelling component, a starting component, a triggering component and a shell, and all the components are mutually matched, so that the whole injector is simple in structure, and the number of parts is greatly reduced;

3. the propelling component is clamped with the limiting component to realize limiting, and the starting component ensures the braking of the propelling component before injection by fixing the limiting form of the propelling component, so that the reliable braking of the starting component before injection is realized;

4. the first bump is designed to have a unidirectional guide slope surface, and can effectively avoid the repeated use of the automatic injector after being matched with the starting sliding sleeve;

5. the second bump is designed to have a unidirectional guide slope, and the braking and propelling state switching of the propelling component can be simply and skillfully realized after the second bump is matched with the starting sliding sleeve.

Drawings

The technical solution and the advantages of the present invention will be apparent from the following detailed description of the embodiments of the present invention with reference to the accompanying drawings.

FIG. 1: explosion diagrams of various parts of the injector of the invention;

FIG. 2: the invention is a sectional view of the internal structure of the injector in an assembled state;

FIG. 3: the invention is a side view of the main shaft of the injector;

FIG. 4: the invention is a side view of the main spring sleeve of the injector;

FIG. 5: the invention is a side view of the starting sliding sleeve of the injector;

FIG. 6: the invention syringe cylinder sliding sleeve side elevation;

FIG. 7: the injector propulsion assembly and the starting assembly are assembled in a pre-fixed state diagram;

FIG. 8: the final state diagram of the assembly of the injector propulsion assembly and the starting assembly of the invention;

FIG. 9: the invention is a sectional view of the internal structure of the injector in an assembled state;

FIGS. 10 to 14: the invention relates to a process chart of the injection of an injector;

FIG. 15: the invention relates to a state diagram of the separation of a pen cap and an injector body of an injector;

FIG. 16: the invention relates to a sleeving state diagram of an injector pen cap and an injector body;

FIG. 17: the invention relates to a shape diagram of a memory material locking piece at high and low temperatures;

FIG. 18: the injector pen cap and the injector body are in a locked state and are in a three-dimensional view;

FIG. 19: the injector pen cap and the injector body are in a locked state and are in a cross-sectional view;

FIG. 20: the invention relates to a cross-sectional view of an injector pen cap and an injector body in an unlocked state.

The parts in the figure are numbered as follows:

1-an injector body, 11-a main shaft, 12-a main spring sleeve, 13-a main spring, 14-a first flange, 15-a first lug, 16-a second lug, 17-a clamping groove, 18-a third lug, 21-a starting sliding sleeve, 22-an auxiliary spring, 23-a second flange, 24-a third groove and 31-a syringe sliding sleeve, 32-through slot, 33-barb, 34-first groove, 4-housing, 41-cartridge, 51-pre-filled syringe, 52-piston, 53-needle shield, 54-cap, 541-second groove, 55-pre-filled syringe flange, 6-memory material lock, 61-memory material lock martensitic shape, 62-memory material lock austenitic shape.

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.

The first embodiment is as follows:

as shown in fig. 15 to 16, an automatic injector comprises an injector body 1 and a pen cap 54, wherein the injector body 1 has an open end, the open end is sleeved with the pen cap 54, the open end has a first groove 34, the pen cap 54 has a second groove 541 which is a through groove, the pen cap 54 is sleeved on the open end of the injector body 1, the first groove 34 and the second groove 541 are overlapped in position, and a groove body with the sum depth is formed after the two groove bodies are overlapped.

The syringe body 1 houses a pre-filled syringe 51 (not shown) with its needle located in the space formed by the syringe body 1 and the cap 54.

Example two:

this example illustrates the preparation of a memory material lock.

Preferably, the memory material lock in the deformed condition has a reversible martensitic start (As) temperature of 10-15 c and completes the martensitic to austenitic transformation at room temperature (Af) (15-25 c), As shown in fig. 17. The austenite shape 62 of the memory material locking member 6 is not particularly limited as long as the shape allows the memory material locking member 6 to have a degree of freedom greater than the depth of the groove formed by the first groove 34 and the second groove 541, and can be removed from the groove, for example, a circle having a radius (inner diameter) greater than that of the cap 54 as shown in fig. 17.

The memory material locking member 6 is formed by drawing the memory material locking member 6 into the martensitic shape 61 at a low ambient or freezing temperature, preferably 0-6 c, without any particular limitation, as long as the shape in which the memory material locking member 6 has a degree of freedom smaller than the depth of the groove formed by the first groove 34 and the second groove 541 cannot be taken out of the groove, for example, an oval shape having a short radius (inner diameter) smaller than the radius of the cap 54, or a standard rectangle having a short side (inner diameter) smaller than the radius of the cap 54 or a rectangle-like shape having four corners in an arc shape, as shown in fig. 17.

Preferred memory materials in the present invention include shape memory alloys. Shape memory alloys exist in both austenitic and martensitic states, undergoing a transformation from austenite to martensite upon cooling, beginning at a higher temperature Ms and ending at a lower temperature Mf, undergoing a transformation from martensite to austenite upon heating, beginning at a lower temperature As and ending at a higher temperature Af.

The shape memory alloy is selected from the group consisting of nickel-titanium alloys, copper-zinc alloys, copper-aluminum-nickel alloys, copper-molybdenum-nickel alloys, copper-gold-zinc alloys, preferably nickel-titanium alloys, preferred alloy materials for making nickel-titanium alloys and their ternary or quaternary modified compositions include binary alloys and alloys containing one or more other metals in addition to nickel and titanium, such as one or more of iron, cobalt, manganese, chromium, vanadium, molybdenum, zirconium, niobium, hafnium, tantalum, tungsten, copper, silver, platinum, palladium, gold, and aluminum.

A preferred example of a binary alloy includes 54.5% to 56.0%, preferably less than 55.5%, nickel and the balance titanium, since alloys of this composition range have a reversible martensitic (martensitic to austenitic) transformation temperature at ambient temperature. Throughout this specification, percentages stated with respect to alloy compositions are weight percentages on an alloy weight basis.

Example three:

as shown in fig. 18-20, for the locking state diagram of the automatic injector in the low temperature storage state and the unlocking state diagram of the automatic injector in the high temperature state, after the open end of the injector body 1 and the pen cap 54 are sleeved, the first groove 34 and the second groove 541 are aligned, the memory material locking piece 6 in the austenite shape 62 is placed at the first groove 34 and the second groove 541, and is placed in the low temperature environment, as shown in fig. 18-19, the memory material locking piece 6 is transformed from the austenite shape 62 to the martensite shape 61, and is snapped into the first groove 34 and the second groove 541, and the locking of the injector is completed.

In use, the locked syringe is left at room temperature for a period of time, and the memory material locking element 6 transforms from the martensitic shape 61 to the austenitic shape 62 and disengages from the first and

second recesses

34 and 541, completing the unlocking of the syringe.

Example four

As shown in fig. 1-6, an autoinjector comprises a main shaft 11, a main spring housing 12, a main spring 13, a start slide 21, an auxiliary spring 22, a syringe slide 31, a housing 4 and a prefilled syringe 51;

the spindle body of the spindle 11 is hollow, one end of the spindle body is closed and is provided with a first flange 14, a plurality of first bumps 15 and second bumps 16 with elasticity are respectively arranged on the spindle body 11 from near to far away from the first flange 14, the first bumps 15 protrude towards the outer surface direction of the spindle body, axial guide slope surfaces are arranged towards the first flange 14 direction, the second bumps 16 protrude towards the inner surface direction of the spindle body, and axial guide slope surfaces are arranged towards the first flange 14 direction;

in an assembly state, the main spring sleeve 12 is positioned in the shaft body of the main shaft 11, one end of the main spring sleeve 12 is closed, the other end of the main spring sleeve is open, the closed end can be inserted into the pre-filling syringe 51, a clamping groove 17 matched with the second bump is arranged on the sleeve body of the main spring sleeve 12, one end of the pre-tightened main spring 13 is propped against the closed end of the main spring sleeve 12, the other end of the pre-tightened main spring 13 is propped against the closed end of the main shaft 11, and the second;

the starting sliding sleeve 21 is sleeved outside the main shaft 11, a second flange 23 is arranged at the far end of the starting sliding sleeve, a third groove 24 capable of accommodating the first lug 15 to slide in the third groove is axially formed in the inner surface of the sliding sleeve, one end of the third groove 24 is open, the other end of the third groove is closed, the opening is positioned at the end, provided with the flange, of the starting sliding sleeve 21, the first lug 15 and the second lug 16 are completely positioned inside the starting sliding sleeve 21, an auxiliary spring 22 is arranged between the first flange 14 and the second flange, and the first lug 15 is clamped at the closed end of the third groove;

after the clamping groove 17 of the main spring sleeve 12 is clamped with the second bump 16 of the shaft body of the main shaft 11, the sleeve body of the starting sliding sleeve 21 tightly presses the second bump 16, so that the second bump 16 of the shaft body of the main shaft 11 and the clamping groove of the main spring sleeve 12 are clamped, and the main spring sleeve 12 is reliably fixed in a locking state with the pretightening force of the main spring 13;

the syringe sliding sleeve 31 can enable the pre-filled syringe 51 to freely slide in the sleeve, a plurality of through grooves 32 are formed in the sleeve body, one end of the syringe sliding sleeve 31 props against the starting sliding sleeve 21, and the length of the other end exceeds the length of a needle of the pre-filled syringe 51, so that the pre-filled syringe 51 is integrally wrapped inside; one end of the syringe sliding sleeve 31, which is propped against the starting sliding sleeve 21, is provided with an inward convex barb; the pre-filled syringe 51 has a plunger 52 and preferably also a needle shield 53;

as shown in fig. 9, the housing 4 is disposed outside the automatic injector, and one end of the housing is fixed to the first flange 14, preferably in a snap-fit manner, and the other end of the housing is shorter than the needle of the pre-filled syringe 51, a plurality of locking blocks 41 are disposed inside the housing 4, the locking blocks 41 pass through the through slots 32 of the syringe sliding sleeve 31 to lock the flange of the pre-filled syringe 51, so that the pre-filled syringe 51 cannot move in the injection direction, and the length of the other end of the housing 4 shorter than the needle determines the puncture depth;

the auto-injector also has a protective cap 54, the cap 54 being removable during use, and when the needle protecting cover 53 is present, it is connected to the needle protecting cover 53, and the needle protecting cover 53 is removable at the same time as the cap 54 is removed.

EXAMPLE five

In this embodiment, as shown in fig. 3, the shaft body wall portion where the first and

second protrusions

15, 16 are located is hollowed out to form a strip with elasticity, the first and

second protrusions

15, 16 are located on the strip, when the elastic strips of the first and

second protrusions

15, 16 are located on a straight line, the width of the strip of the second protrusion 16 is greater than the width of the third groove 24 in the actuating sliding sleeve 21, so that the strip of the second protrusion 16 is not located in the space of the third groove 24 as a whole, and it is ensured that the inner wall of the actuating sliding sleeve 21 can tightly press the second protrusion 16.

EXAMPLE six

In this embodiment, the closed end of the main spring housing 12 is vented to facilitate the timely venting of air between the main spring housing 12 and the plunger of the prefilled syringe 51, and the main spring housing 12 makes quick and unobstructed contact with the plunger 52 after the injection is initiated.

EXAMPLE seven

As shown in fig. 7-8, in this embodiment, the shaft body of the spindle 11 is further provided with a plurality of third elastic protrusions 18 protruding toward the outer surface of the shaft body, and the distance from the first flange 14 is greater than the distance from the first and

second protrusions

15, 16. The third projection 18 serves to facilitate assembly, temporarily fixing the actuating slide 21 and the auxiliary spring 22 to the main shaft 11 before the main spring housing 12 and the main spring 13 are assembled to the main shaft 11.

Example eight

As shown in fig. 10-14, a method for injecting by using the injector comprises the following specific steps:

the method comprises the following steps: the starting stage, taking out the injector from the low-temperature state, placing the injector in the high-temperature state, pulling out the pen cap until the injector is unlocked, placing the sliding sleeve end of the needle cylinder on the skin to be injected, and pressing down; (ii) a

Step two: in the puncturing stage, as shown in fig. 11, the syringe sliding sleeve 31 pushes the starting sliding sleeve 21 to move upward relative to the needle until the needle contacts the skin, pressure is continuously applied, the needle starts to puncture into the skin, the needle sliding sleeve 31 pushes the starting sliding sleeve 21 to move upward until the needle sliding sleeve 31 completely enters the housing 4, and at this time, a predetermined subcutaneous puncture depth is reached, and puncturing is finished; during the puncturing process, the lower end of the starting sliding sleeve 21 moves to the position above the second projection 16, the locking state of the second projection 16 and the locking groove 17 is released, under the thrust action of the main spring 13, the locking groove 17 of the main spring sleeve 12 slides along the axial guiding slope of the second projection 16, the second projection 16 elastically deforms outwards until the locking groove 17 is completely separated from the clamping position of the second projection 16, the main spring 13 pushes the main spring sleeve 12 to continue to move forwards, and the front part of the main spring sleeve 12 contacts and supports against the piston 52 of the prefilled syringe 51;

step three: an injection phase, as shown in fig. 12, in which the pre-filled syringe 51 and the housing 4 are fixed in a clamping manner, the main spring 13 continues to push the main spring housing 12 and the plunger 52, so as to inject the medicine in the pre-filled syringe 51 into the subcutaneous space of the patient, until the plunger 52 reaches the bottommost end of the pre-filled syringe 51, and the injection is finished;

step four: during the resetting stage, as shown in fig. 13-14, the automatic injector is removed, the auxiliary spring 22 pushes the needle sliding sleeve 31 and the actuating sliding sleeve 21 to retract, when the upper end of the actuating sliding sleeve 21 contacts the first projection 15, the upper end of the actuating sliding sleeve 21 slides along the axial guiding slope of the first projection 15, the first projection 15 is elastically deformed inward, and then is disengaged from the actuating sliding sleeve 21 until the barb 33 of the syringe sliding sleeve 31 catches the pre-filled syringe flange 55, and the injection procedure is ended. At this time, the first protrusion 15 has already come out of the starting sliding sleeve 21 and is enclosed in the housing 4, and because there is no guiding slope, the first protrusion 15 cannot enter the starting sliding sleeve 21 again in the reverse direction, if the injector repeats step one, the whole injection process will be blocked, thereby avoiding the reuse of the automatic injector.

The above description is only an exemplary embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes that are transformed by the content of the present specification and the attached drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A low-temperature locking automatic injector is characterized by comprising an injector body, a pen cap and a memory material locking piece,

the injector body is provided with an opening end which is sleeved with the pen cap,

the injector body contains a pre-filled syringe, the needle of the pre-filled syringe is positioned in the space formed by the injector body and the pen cap,

the pen cap and the injector body are locked at low temperature and unlocked at high temperature by the memory material locking piece.

2. The automatic injector of claim 1, characterized in that the open end of the injector body has a first groove and the cap has a second groove, the grooves on the outer part being through grooves when the cap and the injector body are mated, and the two grooves on the parts overlapping in position.

3. The autoinjector of claim 2, wherein said memory material locking element has a martensitic shape at low temperature when said cap and said syringe body are nested, wherein said memory material locking element snaps into said cap and said syringe body recesses, retaining the shape from removal, locking the cap and syringe body; and a memory material locking element which is deformed into an austenitic shape at high temperature, wherein the memory material locking element is disengaged from the grooves of the pen cap and the injector body and unlocks the pen cap and the injector body.

4. The autoinjector of claim 1, wherein the memory material is a memory alloy.

5. The automatic injector of claim 4, wherein said memory alloy is selected from the group consisting of nickel-titanium alloy, copper-zinc alloy, copper-aluminum-nickel alloy, copper-molybdenum-nickel alloy, and copper-gold-zinc alloy.

6. The autoinjector of any of claims 1-2, wherein the syringe body comprises a propulsion assembly, an activation assembly, a trigger assembly, and a housing, the propulsion assembly being located in the activation assembly, the propulsion assembly comprising a propulsion component and a stop component, the propulsion component being retained by engagement with the stop component, the activation assembly ensuring braking of the propulsion assembly prior to injection by securing the retaining form of the propulsion assembly;

the trigger assembly receives the pre-filled syringe and, after an injection is initiated, pushes the actuation assembly out of the braking position;

the shell is wrapped outside the propelling component, the starting component and the triggering component.

7. The automatic injector of claim 6, wherein the propulsion component of the propulsion assembly comprises a main spring housing and a main spring, the limiting component of the propulsion component comprises a main shaft, and the activation assembly comprises an activation slide and an auxiliary spring;

the starting sliding sleeve is sleeved outside the main shaft, a second flange is arranged at the far end of the starting sliding sleeve, a third groove capable of accommodating the first lug to slide in the third groove is axially formed in the inner surface of the sliding sleeve, one end of the third groove is opened, the other end of the third groove is closed, the opening is located at the flange end of the sliding sleeve, the first lug and the second lug are completely located inside the starting sliding sleeve, an auxiliary spring is arranged between the first flange and the second flange, and the first lug is clamped at the closed end of the third groove.

8. The autoinjector of any of claims 6-7, wherein the trigger assembly includes a syringe slide;

the syringe sliding sleeve can enable the pre-filled syringe to freely slide in the sleeve, a plurality of grooves are formed in the sleeve body, one end of the syringe sliding sleeve props against the starting sliding sleeve, the other end of the syringe sliding sleeve is provided with a first groove of the injector body, and the length of the syringe sliding sleeve exceeds the length of a needle head of the pre-filled syringe.

9. The automatic injector of any of claims 6-8, wherein said housing is fitted over the exterior of said automatic injector, and has one end fixed to said first flange and the other end shorter than the length of the needle of the pre-filled syringe, and a plurality of clips are provided inside said housing, said clips being adapted to engage said flange of the pre-filled syringe through slots in said syringe slide.

10. The automatic injector of claim 7, wherein the portion of the shaft wall where the first and second protrusions are located is hollowed out to form a flexible strip.