CN115463289B

CN115463289B - Needleless injector

Info

Publication number: CN115463289B
Application number: CN202211099942.0A
Authority: CN
Inventors: 张明
Original assignee: Beijing Qs Medical Technology Co ltd
Current assignee: Beijing Qs Medical Technology Co ltd
Priority date: 2022-09-07
Filing date: 2022-09-07
Publication date: 2024-04-02
Anticipated expiration: 2042-09-07
Also published as: CN115463289A

Abstract

The invention relates to a needleless injector, which comprises an injection assembly and a medicine storage assembly. The injection assembly includes an injection cavity housing enclosing an injection cavity. The drug storage component is arranged movably relative to the injection component and comprises a drug storage cavity shell, a plug and a drug delivery push rod. The medicine storage cavity shell encloses into the medicine storage cavity, and the medicine storage cavity can be communicated with the injection cavity, and medicine liquid is pre-filled in the medicine storage cavity. The plug is movably disposed in the drug storage chamber. A dosing push rod is movably disposed in the drug storage cavity, wherein the dosing push rod is actuatable to push the plunger in a first direction toward the injection cavity. The needleless injector according to the scheme can accelerate the injection speed and improve the injection efficiency.

Description

Needleless injector

Technical Field

The present invention relates to medical devices for injecting liquid drugs. More particularly, the present invention relates to a needleless injector.

Background

The needleless injector does not need to use a needle, but is a medical device which can be injected into the skin of a patient through micropores at the end part by applying high pressure to liquid medicine, so that the pain of the patient caused by needling can be avoided. Needleless injectors typically include a cartridge and a pusher. The function of the cartridge is to contain the liquid drug.

In general, when using a needleless injector, it is necessary to first mount a cartridge on the needleless injector, then withdraw a medicine from a medicine storage bottle through a needle at the front end of the cartridge, and separate the cartridge from the medicine storage bottle after the medicine withdrawal is completed. It can be seen that the injection operation steps are more and the operation is more complicated.

Accordingly, there is a need to provide a needleless injector that at least partially addresses the above-described problems.

Disclosure of Invention

The present invention provides a needleless injector comprising:

the injection assembly comprises an injection cavity shell, wherein the injection cavity shell encloses an injection cavity; and

a drug storage assembly, the drug storage assembly being disposed relative to the injection assembly, the drug storage assembly comprising:

the medicine storage cavity shell encloses a medicine storage cavity, the medicine storage cavity can be communicated with the injection cavity, and medicine liquid is pre-filled in the medicine storage cavity;

a plug movably disposed in the drug storage chamber;

a dosing push rod is movably disposed in the drug storage cavity, wherein the dosing push rod is actuatable to push the plug in a first direction toward the injection cavity.

In one embodiment, the drug storage assembly has an initial position and an activated position, and is movable between the initial position and the activated position, wherein the drug storage cavity is remote from the injection cavity when the drug storage assembly is in the initial position, and the drug storage cavity is in communication with the injection cavity when the drug storage assembly is in the activated position.

In one embodiment, the needleless injector further comprises an actuation assembly comprising an actuation device configured to actuate the dosing rod in a predetermined state after the drug storage chamber and the injection chamber are in communication.

In one embodiment, the needleless injector further comprises an operating device operable in the first direction to cause the medical fluid in the drug storage chamber to reach the injection chamber.

In one embodiment, the actuation device is in linkage with the operating device, the actuation device being configured to synchronously actuate movement of the dosing push rod in the first direction when the operating device is moved in the first direction.

In one embodiment, the actuating device comprises a rotating part and a nut part, the operating device is provided with an inner spiral structure, one end of the rotating part is provided with an outer spiral structure, the outer spiral structure is engaged in the inner spiral structure, the other end of the rotating part is engaged with the administration push rod and can drive the administration push rod to rotate, and the nut part is in threaded engagement with the periphery of the administration push rod.

In one embodiment, the actuation means comprises a resilient member capable of acting on the dosing rod in the first direction.

In one embodiment, the actuation means comprises a pushing portion arranged outside the dosing rod and engaged inside the operating means, one end of the dosing rod being provided with a stop flange protruding radially outwards, both ends of the elastic member acting on the stop flange and the pushing portion, respectively.

In one embodiment, the push portion is configured to move with the drug storage assembly between the initial position and the activated position, the drug delivery pusher being locked relative to the push portion when the drug storage assembly is in the initial position, the resilient member being in a compressed state, the drug delivery pusher being unlocked relative to the push portion when the drug storage assembly is in the activated position.

In one embodiment, the actuation device further comprises a locking member arranged at the periphery of the pushing part, wherein a recess recessed radially inwards is arranged on the dosing rod, the locking member is partially accommodated in the recess when the drug storage assembly is in the initial position, and the locking member is limited in the radial direction of the dosing rod, and when the drug storage assembly is moved to the activated position, the locking member is released from the limitation in the radial direction of the dosing rod so as to allow the locking member to move radially outwards and be separated from the recess.

In one embodiment, the injection assembly further comprises a piston assembly movably disposed in the injection cavity, a passage communicating with the injection cavity is disposed in the piston assembly, and an injection micropore communicating with the outside and the injection cavity is formed at a front end of the injection cavity housing.

In one embodiment, the needleless injector further comprises an injection pushrod disposed radially outward of the drug storage assembly, the injection pushrod being coupled to the piston assembly and configured to move in synchronization with the piston assembly.

In one embodiment, the needleless injector further comprises a safety device operably disposed between the drug storage chamber and the injection chamber, the safety device being configured to define the drug storage assembly in the initial position when not operated and to move to the activated position when the safety device is operated.

In one embodiment, the safety device is at least partially removably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber when at least partially removed.

In one embodiment, the safety device is rotatably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber after being rotated.

In one embodiment, the safety device is movably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber after being moved and then rotated.

In one embodiment, the safety device is movably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber after being rotated and then moved.

In one embodiment, the medicine storage component further comprises an additional elastic piece, the additional elastic piece is arranged inside the injection push rod, one end of the additional elastic piece acts on the injection push rod, the other end of the additional elastic piece can act on the medicine storage component, and when the medicine storage component is in the initial position, the additional elastic piece is in a compressed state.

In one embodiment, the needleless injector further comprises a housing portion having a substantially cylindrical shape, the housing portion being disposed between the operating device and the injection plunger, the housing portion being connected to the injection cavity housing

In one embodiment, the actuation assembly further comprises a transmission at least partially disposed on the housing portion and configured to translate movement of the operating device in the first direction into movement of the injection pushrod in a second direction, the second direction being opposite the first direction.

In one embodiment, the injection ram is configured to move with the piston assembly between a first position proximate to the injection well and a second position distal to the injection well.

In one embodiment, the needleless injector further comprises a locking device configured to hold the injection plunger in a locked state during movement of the injection plunger from the first position to the second position and to automatically unlock the injection plunger when the injection plunger reaches the second position, wherein the injection plunger is restricted from returning to the first position when in the locked state and is drivable back to the first position when the injection plunger is unlocked.

In one embodiment, the locking device includes a locking sleeve which is fitted over the outside of the injection push rod and is provided on the inside of the housing portion, the locking sleeve has a flange portion protruding radially inward thereof, the locking member is provided on the outer periphery of the injection push rod, when the injection push rod is locked, the locking member protrudes from the outer periphery of the injection push rod and is located at one end of the flange portion away from the injection micropores, and a projection of the locking member on a plane perpendicular to the central axis of the injection push rod and a projection of the flange portion on the plane have overlapping portions.

In one embodiment, the locking member is movable radially towards the central axis of the dosing rod when the injection rod is in the second position, and the projection of the locking member onto the plane does not overlap with the projection of the flange portion onto the plane.

In one embodiment, the end of the dosing rod remote from the injection direction is provided with an additional recess recessed radially inwards, in which the locking element is received when the injection rod is in the second position.

In one embodiment, the locking member moves with the injection pushrod to an end extending beyond the administration pushrod in the second direction when the injection pushrod is in the second position.

In one embodiment, the needleless injector further comprises a drive device configured to drive the injection plunger and the piston assembly back to the first position in the first direction when the injection plunger is unlocked.

In one embodiment, the drive means is configured as a spring, both ends of which are capable of acting on the injection plunger and the locking sleeve, respectively, the spring being in a compressed state when the injection plunger is in the second position.

In one embodiment, the drive means is configured as a balloon, the ends of which are capable of acting on the injection plunger and the locking sleeve, respectively, the balloon being in a compressed state when the injection plunger is in the second position.

In one embodiment, the driving device comprises a first sealing ring and a second sealing ring which are arranged at intervals in the axial direction of the injection push rod, the first sealing ring and the second sealing ring are respectively arranged between the injection push rod and the shell part around the injection push rod, the first sealing ring abuts against one end of the injection push rod, which is close to the injection micropore, the second sealing ring abuts against the locking sleeve, the first sealing ring and the second sealing ring enable a closed space to be formed between the shell part and the injection push rod, and when the injection push rod is in the second position, gas between the shell part and the injection push rod is compressed.

In one embodiment, the transmission device comprises a gear wheel, which is arranged on the housing part, a first rack arranged along the axial direction of the injection push rod is arranged inside the operation device, a second rack arranged along the axial direction of the injection push rod is arranged outside the locking sleeve, and the gear wheel is meshed with the first rack and the second rack respectively.

In one embodiment, the transmission comprises a roller provided on the housing part and a belt engaging with the roller, one end of the belt being connected to the operating device and the other end being connected to the locking sleeve.

In one embodiment, the transmission includes a sprocket provided on the housing portion and a chain engaged with the sprocket, one end of the chain being connected to the operating device and the other end being connected to the locking sleeve.

In one embodiment, the piston assembly includes a piston and a piston rod coupled to the piston, a forward end of the piston rod being engaged with the piston, the passageway including a first passageway disposed in the piston and a second passageway disposed in the piston rod.

In one embodiment, an end of the piston push rod adjacent to the drug storage cavity is provided with a tubular needling member in communication with the second passageway, and the drug storage assembly includes a drug storage plug provided at an end of the drug storage cavity housing, the needling member being configured to pierce the drug storage plug when the drug storage assembly is moved to the activated position.

In one embodiment, the locking element is a sphere or a cylinder extending along an axis perpendicular to the injection pushrod.

According to the scheme, the needleless injector is provided with the medicine storage cavity, and medicine liquid needing to be injected is stored. When injection is needed, the medicine liquid in the medicine storage cavity can be pushed into the injection cavity by only actuating the medicine feeding push rod in the medicine storage cavity to push the plug so as to be ready for injection. According to the scheme, quick injection can be realized, the injection efficiency is improved, and particularly when emergency conditions such as emergency and the like are met, the time can be effectively saved.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. The same or similar reference numbers in the drawings refer to the same or similar parts. It will be appreciated by persons skilled in the art that the drawings are intended to schematically illustrate preferred embodiments of the invention, and that the scope of the invention is not limited in any way by the drawings, and that the various components are not drawn to scale.

Fig. 1 shows a perspective view of a needleless injector according to a first preferred embodiment of the present invention in a cut-away state;

Fig. 2 to 6 show sectional views of a needleless injector according to a first preferred embodiment of the present invention in different operation states, respectively, in which fig. 2 to 6 show the operation of the needleless injector in sequence;

fig. 7 shows a perspective view of a needleless injector in a cut-away state according to a second preferred embodiment of the present invention;

figures 8-12 show cross-sectional views of a needleless injector in different operating conditions, respectively, in accordance with a second preferred embodiment of the present invention, wherein figures 8-12 show the operation of the needleless injector in sequence;

fig. 13 and 14 show cross-sectional views of a needleless injector according to a third preferred embodiment of the present invention in different operating states, respectively; and

fig. 15 shows a cross-sectional view of a needleless injector in accordance with a fourth preferred embodiment of the present invention.

Detailed Description

Hereinafter, a needleless injector according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. What follows is merely a preferred embodiment according to the invention, on the basis of which a person skilled in the art will recognize other ways of implementing the invention, which also fall within the scope of the invention.

It should be noted that, first, the term "front" as used herein refers to the direction in which the drug solution is pushed out when the needleless injector is used, that is, the direction toward the site to be injected, and the opposite direction is referred to as "rear".

Embodiment 1

Fig. 1 shows a schematic view of a needleless injector according to a first preferred embodiment of the present invention in an initial state. Fig. 2 to 6 show sectional views of the needleless injector according to the first preferred embodiment of the present invention in different operation states, respectively, in which fig. 2 to 6 show the operation of the needleless injector in sequence.

Referring first to fig. 1, in one embodiment, a needleless injector 100 generally comprises an injection assembly 101, a drug storage assembly 102, and an actuation assembly 103. Injection assembly 101 is located at the forward end of needleless injector 100. Injection assembly 101 includes an injection chamber housing 104 and a piston assembly 105 disposed in injection chamber housing 104. The injection cavity housing 104 is configured in a cylindrical shape, which encloses an injection cavity. The front end of the injection cavity housing 104 has injection micro-holes 106 communicating with the outside and the injection cavity. When an injection operation is intended, the injection cavity housing 104 may be pressed against a site to be injected, such as the skin of a patient, and when an injection operation (described below) is triggered, a medical fluid in the injection cavity may be injected into the patient via the injection micro-holes 106.

The piston assembly 105 is movably arranged in the injection cavity, in particular the piston assembly 105 is movable in the injection cavity in a first direction towards the injection micro-holes 106 and in a second direction opposite to the first direction. A passageway is provided in the piston assembly 105 that communicates with the injection chamber.

In a preferred embodiment, the piston assembly 105 includes a piston 107 and a piston push rod 108 connected to the piston 107, the front end of the piston push rod 108 being engaged with the piston 107. The front end of the piston 107 is configured as a cone, and the front end of the injection chamber has a shape matching the cone-shaped piston front end. A conical tip may be inserted into injection well 106, with the rear end of piston 107 having a slot portion that engages the front of piston push rod 108. In the illustrated embodiment, the forward end of the piston push rod 108 is engaged with the piston 107 by a snap-fit arrangement 109, it being understood that in other embodiments not shown, the piston push rod 108 and piston 107 may be engaged by other means, such as threaded engagement or bonding.

The piston 107 has a first passageway 110 disposed therein, the first passageway 110 being disposed at an angle to the central axis of the injection chamber in the illustrated preferred embodiment, it being understood that the first passageway 110 may be disposed parallel to the central axis of the injection chamber in other embodiments not shown. A second passage 111 is provided in the piston push rod 108, preferably the second passage 111 extends in the direction of the centre axis of the injection cavity. Preferably, the first passageway 110 and the second passageway 111 are spaced apart in a radial direction of the injection cavity. The first passage 110 and the second passage 111 together form the passage described above. The rear end of the piston push rod 108, i.e., the end remote from the injection micro-hole 106, is provided with a tubular needling member 112, the needling member 112 being in communication with a second passageway 111, which needling member 112 can be used to pierce a drug storage plug 113 (described below) of a drug storage chamber.

As shown in fig. 2 and 3, the drug storage assembly 102 includes a drug storage chamber housing 114, a plug 115, and a drug delivery ram 116. The medicine storage chamber housing 114 encloses a medicine storage chamber in which medicine liquid to be injected can be stored in advance. The front end of the drug storage housing 114 has a drug storage plug 113, the drug storage plug 113 being penetrable by the spike member 112 upon movement of the drug storage assembly 102 to an activated position (described below) to place the drug storage cavity in communication with the passageway of the piston assembly. The stopper 115 may preferably be a rubber stopper movably disposed in the drug storage chamber and having an outer diameter matching the inner diameter of the drug storage chamber. A drug delivery ram 116 is movably disposed in the drug storage chamber, the drug delivery ram 116 being disposed at an end of the plug 115 remote from the injection well 106, the drug delivery ram 116 being capable of pushing the plug 115 in a direction toward the injection well 106. The dosing push rod 116 has a first end provided with a radially outwardly protruding stop flange 117 and a second end opposite the first end, which may act on the plug 115.

In a preferred embodiment, as shown in fig. 1, the needleless injector 100 further includes an injection pushrod 118, where the injection pushrod 118 is sleeve-shaped and is sleeved on the radially outer side of the drug storage cavity housing 114, that is, the injection pushrod 118 has a hollow structure, and the drug storage cavity housing 114 is disposed inside the injection pushrod 118. The forward end of the injection pushrod 118 is connected to the piston pushrod 108 and the injection pushrod 118 is capable of synchronized movement with the piston assembly 105. Illustratively, the injection pushrod 118 may be coupled to the piston pushrod 108 via a snap-fit connection, a threaded connection, or the like.

In a preferred embodiment, with continued reference to fig. 1, the needleless injector 100 further includes a housing portion 119, the housing portion 119 being generally cylindrical and disposed about the outside of the injection plunger 118. Preferably, the housing portion 119 is threadably connected to the injection cavity housing 104. It will be appreciated that in other embodiments not shown, the housing portion 119 may be connected to the injection cavity housing 104 in other ways as well.

In a preferred embodiment, the drug storage assembly 102 is movable between an initial position and an activated position relative to the injection push rod 118. Wherein as shown in fig. 1 and 2, when the drug storage assembly 102 is in the initial position, chu Yaoqiang is remote from the piston assembly 105 and the drug storage chamber is not in communication with the passageway in the piston assembly 105. As shown in fig. 3, when the drug storage assembly 102 is in the activated position, the drug storage assembly 102 is moved to a position adjacent to the piston assembly 105, and the drug storage chamber is engaged with the piston assembly 105, the needle member 112 of the piston push rod 108 pierces the drug storage plug 113 at the front end of the drug storage chamber, so that the drug storage chamber communicates with the passageway.

Needleless injector 100 also includes a safety device 120, safety device 120 being operably disposed between the drug storage chamber and the injection chamber. When the safety device is operated, the communication between the medicine storage cavity and the injection cavity can be realized. When the safety device 120 is not operated, the safety device 120 can block the combination of the medicine storage chamber and the injection chamber, and can also block the action of the operation device 128 (described later). Therefore, the safety device can block the combination of the medicine storage cavity and the injection cavity by the structural characteristics of the safety device, and locking is realized. In a preferred embodiment, a safety device 120 is at least partially removably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber when at least partially removed. As shown in fig. 2, in the illustrated embodiment, the safety 120 is entirely removably disposed between the drug storage chamber and the piston assembly 105. When the safety 120 is disposed between the drug storage cavity and the piston assembly 105, it can act as a barrier to movement of the drug storage assembly 102 and can define the drug storage assembly 102 in an initial position. As shown in fig. 3, when the safety 120 is removed from between the drug storage cavity and the piston assembly 105, the drug storage assembly 102 can be moved to an activated position. In the illustrated embodiment, the safety 120 is configured to communicate between the drug storage chamber and the injection chamber by being removed in its entirety. In other embodiments, not shown, the safety device may also be partially removably disposed between the drug storage chamber and the injection chamber.

In other embodiments, not shown, the unlocking may also be accomplished by other means of operation to effect a change in the structural features of the safeties. For example:

in a preferred embodiment, a safety device is rotatably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber after being rotated.

In another preferred embodiment, the safety device is movably arranged between the drug storage chamber and the injection chamber, the safety device being configured to enable communication between the drug storage chamber and the injection chamber after being moved and then rotated, or the safety device being further configured to enable communication between the drug storage chamber and the injection chamber after being rotated and then moved.

In a preferred embodiment, the housing portion 119 is provided with a first insertion groove 121 opening in a radial direction thereof, and the injection pushrod 118 is provided with a second insertion groove 122 opening in a radial direction thereof, the positions of the first insertion groove 121 and the second insertion groove 122 corresponding when the injection pushrod 118 is in a first position (described later). The safety device 120 includes a grip 123 and a holding plate 124 connected to the grip 123, the holding plate 124 being configured to be inserted between the piston assembly 105 and the medicine storage chamber via the first insertion groove 121 and the second insertion groove 122, the grip 123 being convenient for a user to grip. The retaining plate 124 of the safety device 120 can be inserted between the piston assembly 105 and the medicine storage chamber via the first insertion groove 121 and the second insertion groove 122, and the retaining plate 124 is blocked between the piston assembly 105 and the medicine storage chamber when the safety device 120 is inserted into the first insertion groove 121 and the second insertion groove 122. As shown in fig. 2, the retaining plate 124 has a thickness in the axial direction of the injection cavity so that the piston assembly 105 and the drug storage cavity can be spaced apart by a certain distance. When it is intended to insert the safety device 120 into the first insertion groove 121 and the second insertion groove 122 or to take out the safety device 120 from the first insertion groove 121 and the second insertion groove 122, the operation may be performed by gripping the grip 123.

In addition, the safety device 120 also serves to lock the injection push rod 118 and the housing 119 relative to each other, preventing relative displacement therebetween.

With continued reference to fig. 2 and 3, the drug storage assembly 102 further includes a first resilient member 125 (as an example of an additional resilient member), the first resilient member 125 being disposed within the injection push rod 118. As shown in fig. 2, the interior of the injection push rod 118 is provided with a ring of radially inwardly extending blocking flanges 126 at the end remote from the second insertion slot 122, one end of the first resilient member 125 acting on the blocking flanges 126, e.g. the first resilient member 125 may engage the blocking flanges 126 and the other end may act on the drug storage assembly 102 (described in more detail below). As shown in fig. 2, the first resilient member 125 is in a compressed state when the drug storage assembly 102 is in the initial position, i.e., when the safety 120 is blocked between the drug storage assembly 102 and the piston assembly 105. As shown in fig. 3, when the safety device 120 is removed, the drug storage assembly 102 may move to the activated position under the restoring force of the first resilient member 125 because there is no barrier between the drug storage assembly 102 and the piston assembly 105. In the illustrated embodiment, the first resilient member 125 is configured as a spring and is sleeved on the exterior of the administration push rod 116. It will be appreciated that in other embodiments not shown, the first elastic member 125 may be configured as an airbag or the like.

The actuation assembly 103 is capable of pushing the drug delivery push rod 116 in a direction toward the injection microwells 106 in a predetermined state to push the drug solution in the drug storage chamber into the injection chamber, and is capable of pulling the piston assembly 105 in a direction away from the injection microwells 106 to empty the space of the injection chamber for the drug solution to enter the injection chamber. The structure of the actuation assembly 103 is described in detail below.

The actuation assembly 103 includes an actuation device 127, an operating device 128, and a transmission 129. As shown in fig. 1-6, the operating device 128 is cylindrical, has a hollow structure, and has an open end 130 and a closed end 131. The housing portion 119 and the injection push rod 118 and drug storage chamber assembly therein and the like are assembled inside the operation device 128 via the open end 130. The operation device 128 may be operated by a user, in particular, the operation device 128 may be pressed by the user in a first direction towards the site to be injected.

A transmission 129 is preferably provided on the housing portion 119 and between the operating device 128 and the injection push rod 118, the transmission 129 being configured to convert movement of the operating device 128 in a first direction to movement of the injection push rod 118 in a second direction, the second direction being opposite the first direction. That is, when the operating device 128 is moved in the first direction, the injection push rod 118 may be synchronously moved in the second direction. Because the injection pushrod 118 is coupled to the piston assembly 105, when the injection pushrod 118 moves in the second direction, the piston pushrod 108 may move in the second direction with the injection pushrod 118, thereby freeing up space in the injection cavity. The structure of the transmission 129 will be described in further detail later.

The actuation means 127 is configured to actuate the dosing rod 116 in a predetermined state after the drug storage chamber and the injection chamber are in communication, preferably when the operation means 128 is pressed. When the operating means 128 is pressed, the dosing pushrods 116 are synchronously actuated, so that the plugs 115 can be pushed in a first direction towards the injection micro-holes 106, so that the medical fluid in the drug storage chamber is pushed into the injection chamber via the passageway.

In a preferred embodiment, the injection pushrod 118 is configured to move with the piston assembly 105 between a first position proximate to the injection orifice 106 and a second position distal to the injection orifice 106. Wherein the injection push rod 118 is movable from a first position to a second position when the operating device 128 is operated, and from the second position to the first position under the drive of the drive device 132 (described below). Fig. 2 and 3 show the injection push rod 118 and the piston assembly 105 in a first position, in which the piston assembly 105 is resting against the front end of the injection chamber housing 104. Fig. 4 illustrates the movement of the injection pushrod 118 and the piston assembly 105 from the first position to the second position, with the injection pushrod 118 and the piston assembly 105 in an intermediate position between the first and second positions. Fig. 5 shows the injection push rod 118 in a second position with the piston assembly 105. Fig. 6 shows the injection push rod 118 and the piston assembly 105 triggered to return from the second position to the first position.

Preferably, the needleless injector 100 further comprises a locking device configured to maintain the injection plunger 118 and the piston assembly 105 in a locked state during movement of the injection plunger 118 and the piston assembly 105 in the second direction from the first position to the second position, wherein movement in the first direction is restricted when the injection plunger 118 and the piston assembly 105 are in the locked state. This arrangement allows the injection push rod 118 and piston assembly 105 to remain in the current position throughout movement, while avoiding its return to the first position under the drive of the drive device 132 (described below). Furthermore, the locking means is also capable of automatically unlocking when the injection push rod 118 and the piston assembly 105 reach the second position, thereby unlocking the injection push rod 118 and the locking means, so that the injection push rod 118 and the piston assembly 105 can be returned to the first position under the drive of the drive means 132.

As shown in fig. 1-6, in a preferred embodiment, the locking means comprises a locking sleeve 133 and a locking member 134. The locking sleeve 133 is fitted over the outside of the injection push rod 118 and is provided inside the housing portion 119, the locking sleeve 133 being provided with a ring of flange portions 135 protruding radially inward thereof, and the injection push rod 118 being provided with a ring of step portions 136, respectively. The flange portion 135 engages the step portion 136, and when the injection pushrod 118 is moved in the second direction from the first position to the second position, the step portion 136 may push the flange portion 135 so that the locking device may move with the injection pushrod 118.

The locking piece 134 is provided at the outer periphery of the injection push rod 118 and is located at the rear end of the stepped portion 136. As shown in fig. 2 to 4, when the injection push rod 118 is locked with respect to the locking device, the locking piece 134 protrudes from the outer periphery of the injection push rod 118 and is located at the rear end of the flange portion 135, that is, the end away from the injection micro hole 106, and the projection of the locking piece 134 on a plane perpendicular to the central axis of the injection push rod 118 and the projection of the flange portion 135 on the plane have overlapping portions. This arrangement enables the flange portion 135 to block movement of the lock 134 in the first direction, thereby blocking movement of the injection pushrod 118 forward in the first direction. The locking member 134 is preferably a ball, for example, at least two balls which are uniformly circumferentially arranged. Alternatively, the locking member 134 may be a cylinder extending perpendicular to the central axis of the injection pushrod 118.

In a preferred embodiment, the portion of the dosing push rod 116 near the second end is provided with a radially inwardly recessed first recess 137 (as an example of an additional recess), which first recess 137 allows the locking element 134 to be accommodated therein. When the injection push rod 118 is in the second position, as shown in fig. 5, the locking member 134 is movable radially inwardly, i.e. in a direction towards the centre axis of the dosing push rod 116 into the first recess 137, and when the locking member 134 is radially moved into the first recess 137, the projection of the locking member 134 onto the plane does not overlap with the projection of the flange portion 135 onto the plane, such that the flange portion 135 no longer acts as a stop for the locking member 134, thereby unlocking the injection push rod 118, allowing the injection push rod 118 to be returned to the first position in the first direction under the drive of the drive means 132.

As shown in fig. 2-6, the drive means 132 is preferably configured as a second spring which is sleeved on the outside of the injection push rod 118, the injection push rod 118 being provided with a blocking edge 138 extending radially outwardly thereof near the second insertion slot 122, which blocking edge 138 simultaneously forms the slot wall of the second insertion slot 122. One end of the second spring abuts the locking sleeve 133 and the other end abuts the blocking edge 138 (see fig. 4). The second spring is in a compressed state when the injection push rod 118 is in the second position, such that when the injection push rod 118 is unlocked with respect to the locking device, the injection push rod 118 may be returned to the first position in the first direction by the restoring force of the second spring.

As shown in fig. 2-6, in one embodiment, the transmission 129 includes a gear 139, the gear 139 being disposed on the housing portion 119. The inner wall of the operating means 128 is provided with a first rack 140 arranged in its axial direction, the axial direction of the operating means 128 coincides with the axial direction of the injection push rod 118, the outer wall of the locking sleeve 133 is provided with a second rack 141 arranged in its axial direction, and the axial direction of the locking sleeve 133 coincides with the axial direction of the injection push rod 118. The gear 139 is engaged with the first gear rack 140 and the second gear rack 141, respectively. When the operating device 128 is pressed in the first direction, the locking sleeve 133 can be moved in the second direction together with the injection push rod 118 and the piston assembly 105 by the same distance as the operating device 128 is moved by the rotation and transmission of the gear 139. The direction of movement of the operating means 128 and the locking sleeve 133 is indicated by the arrow in fig. 4. It will be appreciated that in other embodiments not shown, one skilled in the art may also use a double-layer gear or a bevel gear or other similar device to control the proportional relationship between the distance of depression of the operating device 128 and the distance of reverse movement of the injection push rod 118.

Preferably, the transmission 129 may comprise two gears symmetrically arranged about the central axis of the housing portion 119, and the number of the first and second racks corresponds to the number of gears, respectively.

With continued reference to fig. 2-6, the actuation device 127 includes a rotating portion 142, the rotating portion 142 having a hollow structure into which the second end of the drug delivery push rod 116 is engageable. Preferably, the second end of the dosing rod 116 has a non-circular shape, such as square or triangular, and the hollow structure has a shape that mates with the second end of the dosing rod 116 such that the rotating portion 142 is capable of rotating in synchronization with the dosing rod 116. The rear end of the rotating portion 142 has an outer screw structure 143, and an inner screw structure 144 is provided inside the closed end 131 of the operating device 128, and the outer screw structure 143 is engaged in the inner screw structure 144. When the operation device 128 is axially pressed in the first direction, the rotating portion 142 can be rotated under screw engagement of the outer screw structure 143 and the inner screw structure 144, so that the administration push rod 116 can be rotated along with the rotating portion 142.

In a preferred embodiment, the drug delivery push rod 116 has an externally threaded section 145 thereon, and the actuation means 127 further comprises a nut portion 146 threadably engaged on the externally threaded section 145. The nut portion 146 is disposed inside the injection push rod 118 and at one end of the administration push rod 116. Preferably, a limiting member (not shown) is provided between the nut portion 146 and the injection push rod 118, and the limiting member may be, for example, a concave-convex fitting structure provided on an outer surface of the nut portion 146 and an inner surface of the injection push rod 118, respectively, and is configured to limit rotation of the nut portion 146 relative to the injection push rod 118.

In a preferred embodiment, the threads of the rotating portion 142 are threaded in a direction opposite to the threads of the externally threaded section 145 of the administration push rod 116. This arrangement enables the dosing rod 116 to rotate along with the rotating part 142 when the operating means 128 is pressed axially in the first direction, while the dosing rod 116 is axially movable in the first direction under the influence of the nut part 146, pushing the stopper 115 and thus the medical fluid in the drug storage chamber into the injection chamber via the passage in the piston assembly 105.

In a preferred embodiment, the thread lead of the administration push rod 116 and the thread lead of the rotation portion 142 depend on the ratio between the inner cross-sectional area of the injection cavity and the inner cross-sectional area of the drug storage cavity. The internal cross-sectional area of the injection chamber and the internal cross-sectional area of the drug storage chamber mentioned herein are the internal cross-sectional areas of the injection chamber and the main body portion of the drug storage chamber. It is further preferred that the ratio of the thread lead of the rotary part 142 to the thread lead of the administration push rod 116 is equal to the ratio of the cross-sectional area in the drug storage chamber to the cross-sectional area in the injection chamber. When the injection lumen inner cross-sectional area is equal to the drug storage lumen inner cross-sectional area, the thread lead of the rotation portion 142 is equal to the thread lead of the drug delivery push rod 116. When the injection lumen internal cross-sectional area is less than the Chu Yaoqiang internal cross-sectional area, the thread lead of the rotating portion 142 is greater than the thread lead of the administration push rod 116. When the injection lumen cross-sectional area is greater than the drug storage lumen cross-sectional area, the thread lead of the rotating portion 142 is less than the thread lead of the drug delivery push rod 116.

In a preferred embodiment, the end of the housing portion 119 adjacent the closed end 131, i.e., the rear end of the housing portion 119, is provided with a ring of first support edges 147 extending radially inwardly thereof, and the rotating portion 142 has a second support edge 148 extending radially outwardly thereof. Preferably, a bearing 149 is provided between the second support edge 148 and the first support edge 147, whereby friction between the rotating portion 142 and the housing portion 119 can be reduced, and the rotating action of the rotating portion 142 can be made smoother. Preferably, the bearing 149 is a planar thrust bearing.

In one embodiment, the first elastic member 125 is sleeved outside the drug delivery push rod 116, and the other end of the first elastic member can act on the nut portion 146, and the nut portion 146 abuts against the drug storage cavity housing 114. The drug delivery push rod 116 is further provided with a flange 150 extending radially outwardly therefrom, the nut portion 146 abuts the flange 150 at an end remote from the injection well 106 in the initial position of the drug storage assembly 102, and the flange 150 is configured as an end point of one end of the male threaded section 145 to function to prevent the nut portion 146 from being disengaged from the male threaded section 145. During movement of the drug storage assembly 102 from the initial position to the activated position, the restoring force of the first resilient member 125 acts on the nut portion 146 such that the nut portion 146 moves in the first direction pushing the drug storage housing 114 and the flange 150 of the drug delivery push rod 116 such that the drug storage assembly 102 as a whole may move in the first direction.

The process of using the needleless injector 100 will be discussed in detail sequentially with reference to fig. 2-6.

Fig. 2 shows the needleless injector 100 in an initial state. The needleless injector 100 is normally in the state shown in fig. 2 when the user is not using the needleless injector 100. In this state, the safety 120 blocks the drug storage chamber from the plunger 108 of the injection chamber. The first elastic member 125 and the second spring are in a compressed state at this time.

Fig. 3 shows the state in which the safety device 120 is removed. In this state, the nut portion 146 is pushed by the elastic force of the first elastic member 125, thereby transmitting the pushing force to the medicine storage assembly 102, so that the medicine storage assembly 102 moves relative to the injection push rod 118 to be combined with the piston push rod 108. The needling member on the piston push rod 108 pierces the drug storage plug 113 at the end of the drug storage cavity, and conducts the liquid medicine in the drug storage cavity to the passage of the piston push rod 108. The medical fluid may be delivered to the junction of the piston ram 108 and the piston 107 via the second passageway of the piston ram 108. Since the piston 107 is now at the front end of the interior of the syringe housing 104 there is no deformation space, so that the medical fluid does not enter the syringe via the first passage in the piston 107.

Fig. 4 shows the state of the needleless injector 100 when the operating device 128 is in the process of being pressed but not pressed into place. In this process, the operator presses the distal end portion of the injection chamber housing 104 against the skin of the injection site, and presses the operation device 128, thereby moving the operation device 128 in a direction approaching the injection site. During depression of the operating means 128, rotation of the gear 139 causes the assembly of the injection push rod 118, the piston assembly 105 and the locking means to move away from the injection site.

At the same time, during the pressing of the operation device 128, the inner spiral structure of the operation device 128 acts on the outer spiral structure of the rotation part 142, so that the rotation part 142 rotates. The rotary part 142 is formed by transmitting a rotary motion to the administration push rod 116. By the relative rotation of the dosing rod 116 and the nut portion 146, the dosing rod 116 is caused to push the stopper 115 in the medicine storage chamber in the first direction, pushing out a predetermined volume of medicine liquid to the outside of the medicine storage chamber. The liquid medicine is replenished to the junction of the piston 107 and the piston push rod 108 through the second passage 111 in the piston push rod 108. The inner surface of the piston 107 is deformed by the pressure of the liquid medicine, so that the liquid medicine enters the injection cavity through the first passage 110 on the piston 107. Since the injection cavity end is sealed against the injection site skin, the injection micro-holes 106 are sealed so that the medical fluid does not flow out of the interior of the injection cavity.

Fig. 5 shows a state of the needleless injector 100 when the operation device 128 is pressed to a predetermined position. When the operating means 128 is pressed to a predetermined position, the administration feeding set 116 has pushed the stopper 115 inside the medicine storage chamber to a set position to push out a set volume of medicine liquid. It will be appreciated that the set position of the dosing rod 116 determines the dose injected. When the dosing rod 116 is moved to the set position, the injection rod 118 is moved to the second position, the first recess 137 in the dosing rod 116 coincides with the path of movement of the locking member 134 on the injection rod 118, allowing the locking member 134 to move radially inwardly into the first recess 137 in the direction of the central axis of the dosing rod 116, thereby unlocking the engagement of the locking device with the injection rod 118.

When the combination of the locking device and the injection push rod 118 is unlocked, the injection push rod 118 and the piston push rod 108 engaged therewith can be moved from the second position to the first position under the drive of the drive device 132.

Fig. 6 shows the needle-free injector 100 in a state in which the injection push rod 118 and the piston push rod 108 engaged therewith are returned from the second position to the first position under the drive of the drive means 132, i.e. the second spring. In this process, the second spring pushes the injection push rod 118 and the piston push rod 108 to move, and the injection push force is transmitted to the medicine liquid in the injection chamber through the piston 107. The liquid medicine is injected into the body of the patient through the injection micropores 106 at the end of the injection cavity. After the dosing rod 116 is moved into place, the dosing rod 116 no longer continues to push the plug 115 inside the drug storage chamber, and thus the drug solution no longer continues to be delivered into the injection chamber. Elastic deformation of the piston 107 is restored, sealing the passage for drug solution delivery. In the injection process, as the surface of the piston 107 in the injection cavity is pressed by the pressure of the liquid medicine, the joint surface of the piston 107 and the piston push rod 108 is pressed, so that the liquid medicine can be ensured not to flow back into the piston push rod 108.

Embodiment 2

A needleless injector 200 according to a second preferred embodiment of the present invention is described in detail below with reference to fig. 7-12. Except for the structure of the actuating means, the needleless injector 200 according to the second preferred embodiment has substantially the same structure as the needleless injector 100 according to the first preferred embodiment, and thus, only the differences will be described in detail herein for the sake of brevity.

As shown in fig. 7, in a preferred embodiment, the actuating device 227 includes a pushing portion 251 and a third elastic member 252 (as an example of an elastic member). The third elastic member 252 is provided on the outer periphery of the drug delivery push rod 216. The first end of the dosing rod 216 is provided with a radially outwardly protruding stop flange 217 against which stop flange 217 one end of the third resilient member 252 abuts. The pushing part 251 is preferably configured in a sleeve shape, which is disposed inside the injection push rod 218 and sleeved outside the administration push rod 216, and the other end of the third elastic member 252 abuts against the front end of the pushing part 251. One end of the first elastic member 225 abuts against the blocking flange 226, and the other end abuts against the rear end of the pushing part 251, so that the pushing part 251 can be moved from the initial position to the activated position together with the medicine storage assembly 202 under the force of the first elastic member 225. When the drug storage assembly 202 is in the initial position shown in fig. 8, the third elastic member 252 is in a compressed state and the first elastic member 225 is in a compressed state. The third resilient member 252 is preferably a spring and is sleeved on the exterior of the drug delivery ram 216. It will be appreciated that in other embodiments not shown, the third elastic member 252 may be configured as an airbag or the like.

It will be appreciated that when the third elastic member 252 is in a compressed state, elastic force is applied to the stopper flange 217 and the pushing part 251 located at both ends thereof. In order to avoid displacement of the dosing rod 216 and the pushing part 251 under the action of the spring force when the drug storage assembly 202 is in the initial position, in particular in order to avoid that the dosing rod 216 pushes the plug 215 under the action of the spring force in the first direction, the actuation means 227 preferably further comprise a locking member 260, which locking member 260 is capable of locking the dosing rod 216 with respect to the pushing part 251 when the drug storage assembly 202 is in the initial position and of unlocking the dosing rod 216 with respect to the pushing part 251 when the drug storage assembly 202 is in the activated position. In addition, the front end of the pushing part 251 further includes a first stop 261 protruding radially outward, and correspondingly, a step portion forming a second stop 262 is provided inside the injection push rod 218, and the second stop 262 divides the inside of the injection push rod 218 into at least a first receiving part 263 and a second receiving part 264, wherein the cross-sectional area of the first receiving part 263 is larger than the cross-sectional area of the second receiving part 264. The first stop portion 261 and the second stop portion 262 cooperate to block the pushing portion 251 from moving in the second direction under the action of the elastic force. The medicine storage assembly 202 is disposed in the first receiving portion 263.

The locking member 260 is provided on the outer periphery of the push portion 251, and the dosing rod 216 is provided with a radially inwardly recessed second recess 265 (as an example of a recess), and when the drug storage assembly 202 is in the initial position, the locking member 260 is partially located in the second receiving portion 264, is restrained between the second recess 265 of the dosing rod 216 and the injection rod 218 in the radial direction of the dosing rod 216, and abuts against the rear end surface of the second recess 265, so that the dosing rod 216 can be restrained from being displaced in the first direction by the elastic force of the third elastic member 252. During movement of the drug storage assembly 202 from the initial position to the activated position, the push portion 251 and the locking member 260 move into the first receiving portion 263, allowing the locking member 260 to move radially outward because the cross-sectional area of the first receiving portion 263 is larger than the cross-sectional area of the second receiving portion 264. When the locking member 260 is moved radially outwards, it can be disengaged from the second recess without abutting against the rear end surface of the second recess 265, whereby the locking of the dosing rod 216 can be released and it can be displaced in the first direction under the force of the third resilient member 252. The locking member 260 is preferably a ball, for example, at least two balls which are uniformly circumferentially arranged. Alternatively, the locking member 260 may be a cylinder extending along a central axis perpendicular to the pushing part 251.

Further, unlike the first embodiment, in the present embodiment, a portion of the drug delivery push rod 216 near the second end does not have the first concave portion 137. When the injection ram 218 is in the second position, the locking member 234 moves with the injection ram 218 to extend beyond the second end of the dosing ram 216 in the second direction, leaving a free area inside the excess of the injection ram 218, allowing the locking member 234 to move radially inward to the free area, thereby unlocking the injection ram 218, allowing the injection ram 218 to return to the first position in the first direction under the drive of the drive 232.

The procedure for using the needleless injector 200 will be briefly described in sequence with reference to fig. 8-12. This process of use is substantially the same as the process of use of needleless injector 100.

Fig. 8 shows the needleless injector 200 in an initial state. The needleless injector 200 is normally in the state shown in fig. 8 when the user is not using the needleless injector 200. In this state, the safety 220 blocks the drug storage chamber from the plunger 208 of the injection chamber. The first resilient member 225 and the second spring are now in compression.

Fig. 9 shows a state in which the safety device 220 is removed. In this state, the pushing part 251 is pushed by the elastic force of the first elastic member 225, so that the pushing force is transmitted to the medicine storage assembly 202, so that the medicine storage assembly 202 moves relative to the injection push rod 218 to be combined with the piston push rod 208. The needle member on the piston push rod 108 pierces the drug storage plug 213 at the end of the drug storage chamber, and connects the drug solution in the drug storage chamber to the passage of the piston push rod 208. The medical fluid may be delivered to the junction of the piston pushrod 208 and the piston 207 via the passageway of the piston pushrod 208. Since the piston 207 is now at the front end of the interior of the syringe housing 204, there is no room for deformation, so that the medical fluid does not enter the syringe via the first passage 210 in the piston 207.

Fig. 10 shows the state of the needleless injector 200 when the operating device 228 is in the process of being pressed but not pressed into place. In this process, the operator presses the distal end portion of the injection chamber housing 204 against the skin of the injection site, and presses the operation device 228, thereby moving the operation device 228 in a direction approaching the injection site. During depression of the operating device 228, rotation of the gear 239 causes the assembly of the injection push rod 218, the piston assembly 205 and the locking device to move away from the injection site.

Meanwhile, when the elastic force of the third elastic member 252 applied to the medicine push rod 216 is greater than the frictional force between the medicine push rod 216 and the pushing part 251 during the pressing of the operating device 228, the medicine push rod 216 moves in the first direction, pushing the stopper 215 in the medicine storage chamber, and pushing out the predetermined volume of medicine liquid to the outside of the medicine storage chamber. The medical fluid is replenished to the junction of the piston 207 and the piston pushrod 208 through a second passageway 211 in the piston pushrod 208. The inner surface of the piston 207 is deformed by the pressure of the liquid medicine, so that the liquid medicine enters the inside of the injection cavity through the first passage 210 on the piston 207. Since the injection cavity end is sealed against the injection site skin, the injection micropores 206 are sealed so that the drug solution does not flow out of the interior of the injection cavity.

Fig. 11 shows a state of the needleless injector 200 when the operation device 228 is pressed to a predetermined position. When the operating means 228 is pressed to a predetermined position, the dosing rod 216 has pushed the plug 215 inside the drug storage cavity to a set position to push out a set volume of drug solution. When the drug delivery ram 216 is moved to the set position, the injection ram 218 is moved to the second position and the locking member 234 is radially moved into the empty region, thereby unlocking the locking device from engagement with the injection ram 218.

After the engagement of the locking device with the injection push rod 218 is unlocked, the injection push rod 218 and the piston push rod 208 engaged therewith can be moved from the second position to the first position under the drive of the drive device 232.

Fig. 12 shows the needle-free injector 200 when the injection plunger 218 and the piston plunger 208 engaged therewith are returned from the second position to the first position under the drive of the drive means 232 (i.e., the second spring). In this process, the second spring pushes the injection push rod 218 and the piston push rod 208 to move, and the injection push force is transmitted to the medicine liquid in the injection cavity through the piston 207. The medical fluid is injected into the body of the patient through the injection micropores 206 at the end of the injection cavity. After the drug delivery ram 216 is moved into place, the drug delivery ram 216 no longer continues to push the plug 215 inside the drug storage chamber, and thus the drug solution no longer continues to be delivered into the injection chamber. Elastic deformation of the piston 207 is restored, sealing the passage of the drug solution delivery. In the injection process, the surface of the piston 207 in the injection cavity is pressed by the liquid medicine, so that the joint surface of the piston 207 and the piston push rod 208 is pressed, and the liquid medicine can be prevented from flowing back into the piston push rod 208.

Embodiment 3

A needleless injector 300 in accordance with a third preferred embodiment of the present invention is described in detail below with reference to fig. 13-14. Except for the structure of the transmission, the needleless injector 300 according to the third preferred embodiment has substantially the same structure as the needleless injector 100 according to the first preferred embodiment, and thus, only the differences will be described in detail herein for the sake of brevity.

Fig. 13 shows the needleless injector 300 when the drug storage assembly 302 is in an initial position. In this embodiment, the transmission 329 comprises a roller 371 and a strap 372 engaged with the roller 371, the roller 371 being disposed on the housing portion 319, a first end of the strap 372 being connected to the operating device 328 and being capable of moving with the operating device 328 in a first direction, a second end of the strap 372 being connected to the locking sleeve 333 such that when the operating device 328 is moved in the first direction, as shown in fig. 14, the first end of the strap 372 is capable of rotating the roller 371 such that the second end of the strap 372 is capable of moving the locking sleeve 333 with the injection push rod 318 in a second direction opposite the first direction.

In other embodiments not shown, the transmission may further comprise a sprocket provided on the housing part and a chain engaged with the sprocket, one end of the chain being connected to the operating device and the other end being connected to the locking sleeve.

Embodiment 4

A needleless injector 400 according to a fourth preferred embodiment of the present invention is described in detail below with reference to fig. 15. Except for the structure of the driving means, the needleless injector 400 according to the fourth preferred embodiment has substantially the same structure as the injector 100 according to the first preferred embodiment, and thus, only the differences will be described in detail herein for the sake of brevity.

In the present embodiment, a cavity between the housing portion 419 and the injection plunger 418 is closed, and gas in the cavity can be compressed and stored. In order to ensure the tightness of the cavity, a first seal ring 481 and a second seal ring 482 are arranged at intervals in the axial direction of the injection push rod 418, the first seal ring 481 and the second seal ring 482 being respectively disposed between the injection push rod 418 and the housing portion 419 around the injection push rod 418, the first seal ring 481 abutting against the front end of the injection push rod 418, that is, the end near the injection micro-hole 406, the second seal ring 482 abutting against the locking sleeve 433. When injection ram 418 is in the second position, gas between housing portion 419 and injection ram 418 is compressed and stored. Thus, when injection pushrod 418 is unlocked, it may be moved from the second position to the first position under the urging of compressed gas.

The foregoing description of various embodiments of the invention has been presented for the purpose of illustration to one of ordinary skill in the relevant art. It is not intended that the invention be limited to the exact embodiment disclosed or as illustrated. As above, many alternatives and modifications of the present invention will be apparent to those of ordinary skill in the art in light of the above teachings. Thus, while some alternative embodiments have been specifically described, those of ordinary skill in the art will understand or relatively easily develop other embodiments. The present invention is intended to embrace all alternatives, modifications and variations of the present invention described herein and other embodiments that fall within the spirit and scope of the invention described above.

Claims

1. A needleless injector, wherein the needleless injector is a disposable needleless injector, comprising:

an injection assembly (101) comprising an injection cavity housing (104) enclosing an injection cavity; and

a drug storage assembly (102) movably disposed relative to the injection assembly, the drug storage assembly comprising:

a medicine storage cavity shell (114) which encloses a medicine storage cavity, wherein the medicine storage cavity can be communicated with the injection cavity, and medicine liquid is pre-filled in the medicine storage cavity;

A plug (115) movably disposed in the drug storage cavity;

a dosing push rod (116) movably arranged in the drug storage cavity, wherein the dosing push rod can be actuated to push the plug (115) along a first direction towards the injection cavity,

an actuation assembly (103) comprising an actuation means (127), the actuation means (127) being configured to actuate the dosing rod (116) in a predetermined state after communication of the drug storage chamber and the injection chamber, the actuation means comprising an elastic member (252) capable of acting on the dosing rod in the first direction,

wherein the drug storage assembly (102) has an initial position and an activated position, and is movable between the initial position and the activated position, wherein the drug storage cavity is remote from the injection cavity when the drug storage assembly (102) is in the initial position, and the drug storage cavity is in communication with the injection cavity when the drug storage assembly (102) is in the activated position.

2. A needleless injector as in claim 1, further comprising an operating device (128) operable in the first direction to cause the medical fluid in the drug storage chamber to reach the injection chamber.

3. A needleless injector as in claim 2, in which the actuation means (127) is in linkage with the operating means (128), the actuation means (127) being configured to simultaneously actuate movement of the dosing push rod in the first direction as the operating means moves in the first direction.

4. A needleless injector as claimed in claim 3, in which the actuation means comprises a push part (251), the push part (251) being provided externally of the dosing push rod (216) and engaging inside the operating means, one end of the dosing push rod (216) being provided with a radially outwardly projecting stop flange (217), the two ends of the resilient member (252) acting on the stop flange (217) and the push part (251), respectively.

5. The needle-free injector of claim 4, wherein the push portion (251) is configured to move with the drug storage assembly (202) between the initial position and the activated position, the drug delivery ram (216) being locked relative to the push portion (251) when the drug storage assembly (202) is in the initial position, the resilient member (252) being in a compressed state, the drug delivery ram (216) being unlocked relative to the push portion (251) when the drug storage assembly (202) is in the activated position.

6. The needle free injector of claim 5, wherein said actuation means (127) further comprises a locking member (260) disposed on an outer periphery of said push portion (251), said dosing push rod (116) being provided with a radially inwardly recessed recess (265), said locking member being partially received in said recess when said drug storage assembly (102) is in said initial position and being restrained in a radial direction of said dosing push rod, said locking member being restrained in a radial direction of said dosing push rod when said drug storage assembly is moved to said activated position to permit said locking member to move radially outwardly out of said recess.

7. The needleless injector of claim 2, wherein the injection assembly further comprises a piston assembly movably disposed in the injection chamber, the piston assembly (105) having a passageway disposed therein in communication with the injection chamber, the front end of the injection chamber housing (104) having an injection orifice (106) in communication with the outside and the injection chamber.

8. The needle-free injector of claim 7, wherein the needle-free injector (100) further comprises an injection pushrod (118), the injection pushrod (118) being disposed radially outward of the drug storage assembly (102), the injection pushrod (118) being coupled to the piston assembly (105) and configured to move synchronously with the piston assembly (105).

9. The needleless injector of claim 8, further comprising a safety device (120), the safety device (120) being operably disposed between the drug storage cavity and the injection cavity, the safety device being configured to define the drug storage assembly (102) in the initial position when not operated, and the drug storage assembly (102) being movable to the activated position when the safety device (120) is operated.

10. The needleless injector of claim 9, wherein the safety device (120) is at least partially removably disposed between the drug storage cavity and the injection cavity, the safety device being configured to enable communication of the drug storage cavity and the injection cavity when at least partially removed.

11. The needleless injector of claim 9, wherein the safety device is rotatably disposed between the drug storage chamber and the injection chamber, the safety device being configured to enable communication of the drug storage chamber and the injection chamber after being rotated.

12. The needleless injector of claim 9, wherein the safety is movably disposed between the drug storage chamber and the injection chamber, the safety being configured to enable communication of the drug storage chamber and the injection chamber after being moved and then rotated.

13. The needleless injector of claim 9, wherein the safety is movably disposed between the drug storage chamber and the injection chamber, the safety being configured to enable communication of the drug storage chamber and the injection chamber after being rotated and then moved.

14. The needle free injector of claim 9, wherein the drug storage assembly (102) further comprises an additional elastic member (125), the additional elastic member (125) being disposed inside the injection plunger (118), one end of the additional elastic member (125) acting on the injection plunger (118) and the other end being capable of acting on the drug storage assembly (102), the additional elastic member (125) being in a compressed state when the drug storage assembly (102) is in the initial position.

15. The needle-free injector of claim 8, further comprising a housing portion (119), the housing portion (119) being generally cylindrical, the housing portion (119) being disposed between the operating device (128) and the injection plunger (118), the housing portion (119) being connected to the injection cavity housing (104).

16. The needle-free injector of claim 15, wherein the actuation assembly (103) further comprises a transmission (129), the transmission (129) being at least partially disposed on the housing portion (119) and configured to convert movement of the operating device (128) in the first direction to movement of the injection plunger (118) in a second direction, the second direction being opposite the first direction.

17. The needle-free injector of claim 16, wherein the injection ram (118) is configured to be movable with the piston assembly (105) between a first position proximate to the injection well (106) and a second position distal to the injection well (106).

18. The needle-free injector of claim 17, further comprising a locking device configured to hold the injection plunger (118) in a locked state during movement of the injection plunger (118) from the first position to the second position and to automatically unlock the injection plunger (118) when the injection plunger (118) reaches the second position, wherein the injection plunger (118) is restricted from returning to the first position when in the locked state and is drivable back to the first position when the injection plunger (118) is unlocked.

19. The needleless injector as in claim 18, wherein the locking means comprises a locking sleeve (133) and a locking member (134), the locking sleeve (133) being disposed externally of the injection plunger (118) and disposed inside the housing portion (119), the locking sleeve (133) having a flange portion (135) protruding radially inwardly thereof, the locking member (134) being disposed at an outer periphery of the injection plunger (118), the locking member (134) protruding from the outer periphery of the injection plunger (118) and being located at an end of the flange portion (135) remote from the injection micro-hole (106), and a projection of the locking member (134) on a plane perpendicular to a central axis of the injection plunger (118) having an overlapping portion with a projection of the flange portion (135) on the plane.

20. The needle-free injector of claim 19, wherein the locking member (134) is movable radially toward a central axis of the dosing rod (116) when the injection rod (118) is in the second position, and wherein a projection of the locking member (134) onto the plane does not overlap with a projection of the flange portion (135) onto the plane.

21. A needleless injector as claimed in claim 20, in which an end of the dosing push rod (116) remote from the injection direction is provided with an additional recess (137) recessed radially inwards, the lock (134) being received in the additional recess (137) when the injection push rod (118) is in the second position.

22. The needle-free injector of claim 20, wherein the locking member (234) moves with the injection plunger (218) to extend beyond an end of the dosing plunger (216) in the second direction when the injection plunger (218) is in the second position.

23. The needle-free injector of claim 19, further comprising a drive device (132), the drive device (132) configured to drive the injection ram (118) and the piston assembly back to the first position in the first direction when the injection ram (118) is unlocked.

24. A needleless injector as in claim 23, in which the drive means (132) is configured as a spring, both ends of which are capable of acting on the injection plunger (118) and the locking sleeve (133), respectively, the spring being in a compressed state when the injection plunger (118) is in the second position.

25. A needleless injector as in claim 23, in which the drive means (132) is configured as a balloon, the ends of which are capable of acting on the injection plunger (118) and the locking sleeve (133), respectively, the balloon being in a compressed state when the injection plunger (118) is in the second position.

26. The needleless injector of claim 23, wherein the drive means comprises first and second sealing rings (481, 482) arranged at intervals in an axial direction of the injection ram (418), the first and second sealing rings being disposed between the injection ram (118) and the housing portion (119) around the injection ram (118), respectively, the first sealing ring abutting against an end of the injection ram (118) adjacent to the injection micro-bore (106), the second sealing ring abutting against the locking sleeve (133), the first and second sealing rings (481, 482) causing a closed space between the housing portion (119) and the injection ram (118), the gas between the housing portion (119) and the injection ram (118) being compressed when the injection ram (118) is in the second position.

27. The needle-free injector according to claim 19, characterized in that the transmission means (129) comprises a gear (139), the gear (139) being provided on the housing part (119), the operating means (128) being internally provided with a first rack (140) arranged along the axial direction of the injection push rod (118), the locking sleeve (133) being externally provided with a second rack (141) arranged along the axial direction of the injection push rod (118), the gear (139) being in engagement with the first rack (140) and the second rack (141), respectively.

28. The needleless injector of claim 19, wherein the transmission (329) comprises a roller (371) provided on the housing portion (319) and a belt (372) engaged with the roller, one end of the belt being connected to the operating means (328) and the other end being connected to the locking sleeve (333).

29. A needleless injector as in claim 19, in which the transmission (129) comprises a sprocket and a chain engaged with the sprocket, the sprocket being provided on the housing portion (119), one end of the chain being connected to the operating means (128) and the other end being connected to the locking sleeve (133).

30. The needle-free injector of claim 7, wherein the piston assembly (105) comprises a piston (107) and a piston ram (108) connected to the piston (107), a forward end of the piston ram (108) being engaged with the piston (107), the passageway comprising a first passageway (110) disposed in the piston (107) and a second passageway (111) disposed in the piston ram (108).

31. The needleless injector of claim 30, wherein an end of the piston ram (108) adjacent the drug storage chamber is provided with a tubular spike member (112), the spike member (112) being in communication with the second passageway (111), the drug storage assembly (102) comprising a drug storage plug (113) provided at an end of the drug storage chamber housing (114), the spike member being configured to puncture the drug storage plug when the drug storage assembly (102) is moved to the activated position.

32. The needle-free injector of claim 19, wherein the locking element (134) is a sphere or a cylinder extending along an axis perpendicular to the injection push rod (118).