CN111658848A

CN111658848A - Screw-thread type syringe

Info

Publication number: CN111658848A
Application number: CN202010657834.5A
Authority: CN
Inventors: 钟洁愉
Original assignee: Peking University Shenzhen Hospital
Current assignee: Peking University Shenzhen Hospital
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2020-09-15

Abstract

The invention discloses a threaded injector, which comprises a needle cylinder, a push rod, a piston assembly and a threaded sleeve fitting, wherein the needle cylinder is provided with a far end and a near end, the push rod is provided with external threads, the push rod is provided with a connecting end and an operating end, the connecting end penetrates into the needle cylinder through the far end and is adjacent to the near end, and the operating end is kept outside the needle cylinder and is suitable for a user to operate and push the push rod to slide in the needle cylinder; the piston component is arranged at the connecting end and can slide in the needle cylinder along with the push rod; the thread sleeve matching part is detachably connected at the far end and provided with a thread hole, and the push rod penetrates through the thread hole and is in thread fit with the thread hole through external threads. The threaded injector provided by the embodiment of the invention is convenient to operate, more accurate in control of the suction amount and especially suitable for suction of thick liquid. In addition, the thread matching part can be detached from the far end, so that when the syringe is used as a common syringe, the thread matching part can be detached and removed, and the use is flexible and convenient.

Description

Screw-thread type syringe

Technical Field

The invention relates to a syringe, in particular to a threaded syringe.

Background

Syringes are a common medical device. As early as the 15 th century, kathler, italian, proposed the principle of the syringe. Gas or liquid is primarily drawn or injected with a needle.

In some treatment methods, it is necessary to suck fluid in a patient's body using a syringe, for example, chocolate cysts, abscesses, or thick blood using a syringe, and since the fluid has a high consistency, a negative pressure is formed inside the syringe during suction, and if a doctor or a caregiver releases a push rod of the syringe, the push rod is retracted under the negative pressure, resulting in an insufficient suction amount, and for this reason, the doctor or the caregiver needs to keep the push rod of the syringe still, the holding action of the doctor or the caregiver causes inconvenience to the doctor or the caregiver, and it is inconvenient to control the suction amount by such a push-pull suction manner.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, the invention proposes a screw-type injector.

To achieve the above object, a screw-type syringe according to an embodiment of the present invention includes:

a barrel having a distal end and a proximal end;

the push rod is provided with an external thread and is provided with a connecting end and an operating end, the connecting end penetrates into the needle cylinder through the far end and is adjacent to the near end, and the operating end is kept outside the needle cylinder and is suitable for a user to operate and push the push rod to slide in the needle cylinder;

the piston assembly is arranged at the connecting end and can slide in the needle cylinder along with the push rod;

the thread sleeve fitting is detachably connected to the far end and provided with a threaded hole, and the push rod penetrates through the threaded hole and passes through the external thread and the threaded hole in threaded fit.

According to the threaded injector provided by the embodiment of the invention, the push rod is provided with the external thread, the far end of the needle cylinder is provided with the detachable threaded sleeve fitting, and the threaded sleeve fitting is in threaded fit with the push rod, so that suction can be realized by rotating the push rod when thick liquid is sucked, the suction mode can ensure that the push rod cannot be retracted by negative pressure, the operation of doctors or nursing personnel is convenient, and the suction amount is more accurately controlled because the threaded sleeve fitting is in threaded fit with the push rod and the movement precision of the push rod is high. In addition, the thread matching part can be detached from the far end, so that when the syringe is used as a common syringe, the thread matching part can be detached and removed, and the use is flexible and convenient.

In addition, the screw-type injector according to the above-described embodiment of the present invention may further have the following additional technical features:

according to one embodiment of the invention, the piston assembly comprises:

the sliding sleeve is positioned in the needle cylinder and is arranged on the push rod in a sliding manner;

the piston is connected to the connecting end, and the peripheral surface of the piston and the inner wall of the needle cylinder form sealing;

the elastic piece is arranged between the sliding sleeve and the push rod;

when the push rod slides to a preset position in a direction away from the near end, one end of the sliding sleeve abuts against the threaded sleeve matching part, and the elastic part is compressed.

According to an embodiment of the present invention, the piston is configured as a compressible structure, and when the push rod slides to a predetermined position away from the proximal end, the piston abuts against the other end of the sliding sleeve and is pressed by the pressure applied by the connecting end to expand radially outwards, so that the outer peripheral surface of the piston is tightly sealed with the syringe barrel, wherein the pressure is along the axial direction of the syringe barrel and towards the distal end.

According to one embodiment of the invention, the connection end comprises:

one end of the first cylindrical section is connected with the push rod, and a first annular retaining shoulder protruding in the radial direction is formed at the other end of the first cylindrical section;

the sliding sleeve is sleeved on the first cylindrical section, and one end of the sliding sleeve is provided with a third annular retaining shoulder which protrudes inwards along the radial direction; the elastic piece is a spring, the spring is sleeved on the first cylindrical section, one end of the spring abuts against the first annular blocking shoulder, and the other end of the spring abuts against the third annular blocking shoulder.

According to an embodiment of the invention, the connection end further comprises:

one end of the second cylindrical section is coaxially connected with the other end of the first cylindrical section, and a second annular retaining shoulder protruding in the radial direction is formed at the other end of the second cylindrical section;

the piston is provided with a sleeving hole, the sleeving hole comprises a sleeving section and an inner block, one end of the sleeving section penetrates to one end, far away from the near end, of the piston, the inner block is connected with the other end of the sleeving section and does not penetrate through the piston, and the diameter of the inner block is larger than that of the sleeving section;

the second cylindrical section is sleeved in the sleeving section in a penetrating mode, and the second annular retaining shoulder is embedded in the inner block.

According to one embodiment of the invention, the piston comprises:

a cylindrical body;

an annular seal portion formed on an outer peripheral surface of the cylindrical body and protruding outward in a radial direction of the cylindrical body;

and an annular hole is formed in the cylindrical body and surrounds the axis of the cylindrical body, and is correspondingly positioned on the inner side of the annular sealing part, so that when the piston is extruded, the annular hole is flattened, and the annular sealing part expands outwards in the radial direction.

According to one embodiment of the invention, the annular sealing parts and the annular holes are all multiple, the annular sealing parts are arranged at intervals along the axial direction of the cylindrical body, and the annular holes correspond to the annular sealing parts one by one.

According to one embodiment of the present invention, the distal end has two opposite ears, each of the ears having a locking hole;

the threaded sleeve fitting comprises:

a threaded sleeve insertable into and extractable from said distal end, said threaded sleeve having said threaded bore;

the end plate is connected to one end of the threaded sleeve, and the threaded hole penetrates through the end plate;

the two buckles are oppositely arranged on the end plate, the two buckles are in one-to-one correspondence with the two clamping holes, and each buckle is clamped with one corresponding clamping hole to relatively fix the threaded sleeve with the far end.

According to an embodiment of the present invention, further comprising:

the syringe needle, the syringe needle with the connection can be dismantled to the near-end, just the syringe needle with form sealedly through the sealing washer between the near-end.

According to one embodiment of the invention, the proximal end has a nipple projecting in the axial direction;

the needle head is provided with a needle head sleeve, an L-shaped clamping groove is arranged on the peripheral wall of the needle head sleeve and comprises an axial section and a circumferential section, the axial section extends along the axial direction of the needle head, one end of the axial section is opened to form an opening, and the circumferential section extends around the circumferential direction of the needle head and is communicated with the axial section; an annular step surface is arranged in the needle head sleeve, and the sealing ring is arranged on the annular step surface;

the outer peripheral surface of the sleeve joint mouth is provided with a clamping part, the clamping part extends along the radial direction of the sleeve joint mouth, when the needle head sleeve is sleeved with the sleeve joint mouth, the clamping part enters the axial section from the opening, and after the needle head sleeve rotates for a preset angle around the axis of the sleeve joint mouth, the clamping part enters the circumferential section, so that the needle head sleeve is fixedly sleeved with the sleeve joint mouth, and the sealing ring is tightly pressed on the annular step surface by the end surface of the sleeve joint mouth.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

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

FIG. 1 is a schematic structural view of a screw-type syringe according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a screw-type syringe according to an embodiment of the present invention;

FIG. 3 is an exploded view of a screw-type syringe according to an embodiment of the present invention;

FIG. 4 is a disassembled view of the needle and the barrel of the screw-type injector according to the embodiment of the present invention;

FIG. 5 is an exploded view of the plunger and plunger assembly of the screw-type injector according to the embodiment of the present invention.

Reference numerals:

a needle cylinder 10;

a proximal end D10;

a distal end D11;

a sleeving connection nozzle 101;

a locking portion 1011;

an ear portion 102;

a card hole 1021;

a push rod 20;

a connection end D20;

an operation end D21;

external threads 201;

a first cylindrical section 202;

a first annular stop 2021;

a second cylindrical section 203;

a second annular shoulder 2031;

a piston assembly 30;

a sliding sleeve 301;

a third annular shoulder 3011;

a piston 302;

a cylindrical body 3021;

an annular seal portion 3022;

an annular bore 3023;

an elastic member 303;

a threaded sleeve fitting 40;

a threaded sleeve 401;

an end plate 402;

a buckle 403;

a needle 50;

needle cover 501;

l-shaped slot 5011;

axial segment 5012 a;

circumferential segment 5012 b;

and a seal ring 51.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be illustrative of the present invention and should not be construed as limiting the present invention, and all other embodiments that can be obtained by one skilled in the art based on the embodiments of the present invention without inventive efforts shall fall within the scope of protection of the present invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," "radial," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The screw-type syringe according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 to 5, a screw-type injector according to an embodiment of the present invention, which can be used for pumping or injecting a fluid, particularly for pumping a thick fluid, includes a cylinder 10, a push rod 20, a piston assembly 30, and a screw fitting 40.

Specifically, barrel 10 has a distal end D11 and a proximal end D10, wherein distal end D11 refers to the end that is distal to the patient in use and proximal end D10 refers to the end that is proximal to the patient in use, wherein proximal end D10 may be connected to needle 50.

The push rod 20 has an external thread 201, and the push rod 20 has a connecting end D20 and an operating end D21, the connecting end D20 penetrates into the syringe 10 through the distal end D11 and is adjacent to the proximal end D10, the operating end D21 is kept outside the syringe 10 and is suitable for a user to operate and push the push rod 20 to slide in the syringe 10.

The piston assembly 30 is disposed at the connecting end D20 and can slide with the push rod 20 in the barrel 10, that is, the piston assembly 30 can slide in the barrel 10 when the push rod 20 moves axially, and suction can be performed when the piston 302 moves towards the distal end D11.

The threaded sleeve fitting 40 is detachably connected to the distal end D11, and the threaded sleeve fitting 40 has a threaded hole through which the push rod 20 passes and is threadedly engaged with the threaded hole through the external thread 201. That is, the threaded fitting 40 is detachably connected to the distal end D11, for example, by means of a snap 403, etc., and the push rod 20 is threadedly engaged with the threaded fitting 40, so that the push rod 20 can be driven to slide in the axial direction of the cylinder 10 by rotating the operating end D21. In use, the needle 50 can be inserted into a patient, the push rod 20 slides in a direction away from the proximal end D10 by operating the end D21, and accordingly, the piston assembly 30 moves towards the distal end D11, so that the liquid in the patient can enter the syringe 10 from the needle 50, and thus, the liquid can be drawn.

It should be noted that, during the suction, if the liquid is thick, a large negative pressure is formed in the syringe 10, and due to the cooperation of the push rod 20 and the thread bushing fitting 40, the negative pressure does not cause the push rod 20 to retract, and at this time, a large negative pressure state can be maintained in the syringe 10, so that the thick liquid can be sucked into the syringe 10 more quickly and smoothly, and the suction effect and efficiency of the thick liquid are improved.

According to the screw-type injector provided by the embodiment of the invention, the push rod 20 is provided with the external thread 201, the detachable screw sleeve fitting 40 is arranged at the far end D11 of the needle cylinder 10, the screw sleeve fitting 40 is in screw thread fit with the push rod 20, so that when thick liquid is sucked, suction can be realized by rotating the push rod 20, the suction mode can prevent the push rod 20 from being retracted by negative pressure, the operation of a doctor or a nursing staff is convenient, and the precision of the movement of the push rod 20 is high due to the screw thread fit of the screw sleeve fitting 40 and the push rod 20, so that the control of the suction amount is more accurate. In addition, the threaded sleeve fitting 40 can be detached from the far end D11, so that when the syringe is used as a common syringe, the threaded sleeve fitting 40 can be detached and removed, and the syringe is flexible and convenient to use.

Referring to fig. 2 to 3 and 5, in some embodiments of the present invention, the piston assembly 30 includes a sliding sleeve 301, a piston 302 and an elastic member 303, wherein the sliding sleeve 301 is located inside the syringe 10 and slidably disposed on the push rod 20; the piston 302 is connected to the connecting end D20, and the peripheral surface of the piston 302 forms a seal with the inner wall of the syringe 10; the elastic piece 303 is arranged between the sliding sleeve 301 and the push rod 20; when the push rod 20 slides to a predetermined position away from the proximal end D10, one end of the sliding sleeve 301 abuts against the threaded sleeve fitting 40, and the elastic member 303 is compressed.

That is, in this embodiment, a sliding sleeve 301 is sleeved on the plunger 20, and an elastic member 303 is disposed between the sliding sleeve 301 and the plunger, wherein the elastic member 303 can provide an axial force and act on the sliding sleeve 301 and face the distal end D11 of the syringe 10. When the push rod 20 slides away from the proximal end D10, the sliding sleeve 301 and the piston 302 move towards the distal end D11, when the sliding sleeve 301 contacts the threaded sleeve fitting 40, the push rod 20 continues to rotate, so that when the push rod 20 continues to move to a predetermined position, the predetermined position may refer to an extreme position of the push rod 20 moving away from the proximal end D10, in the process, the sliding sleeve 301 is blocked by the threaded sleeve fitting 40 and cannot continue to slide, and the push rod 20 continues to move, at this time, the elastic member 303 is further compressed, so that, on one hand, when the push rod 20 approaches the predetermined position, a larger rotating force needs to be applied when the push rod 20 is rotated due to the force of the elastic member 303, which is convenient for a doctor or a caregiver to know that the predetermined position is about to be reached, and then the push rod 20 is slowly adjusted, so as. On the other hand, the action force provided by the elastic member 303 can keep the push rod 20 stable and reliable, and is not easy to shake, thereby ensuring more reliable and stable suction.

Referring to fig. 2 to 3 and 5, in some embodiments of the present invention, the piston 302 is configured as a compressible structure, and when the push rod 20 slides to a predetermined position away from the proximal end D10, the piston 302 abuts against the other end of the sliding sleeve 301 and is pressed by the pressure applied by the connecting end D20 to expand radially outwards, so that the outer circumferential surface of the piston 302 is tightly sealed with the syringe 10, wherein the pressure is along the axial direction of the syringe 10 and toward the distal end D11.

That is, the piston 302 and the sliding sleeve 301 abut against each other, and during the movement of the plunger 20 away from the proximal end D10, when the sliding sleeve 301 contacts the threaded sleeve fitting 40, the sliding sleeve 301 continues to rotate, so that the plunger 20 continues to move to a predetermined position, during which the sliding sleeve 301 is blocked by the threaded sleeve fitting 40 and cannot continue to slide, and the plunger 20 continues to move, at which time, since the connecting end D20 pulls the piston 302 toward the distal end D11, and the sliding sleeve 301 stops at the side of the piston 302 close to the distal end D11, the piston 302 is squeezed, and the squeezed piston 302 expands in the radial direction, and can be pressed against the syringe 10, so that the seal between the piston 302 and the syringe 10 can be better.

In the syringe according to the related art, although the piston 302 is fitted to the cylinder 10 to achieve sealing, the sealing effect is not satisfactory for maintaining the negative pressure for a long time without leakage of air, because the negative pressure inside the cylinder 10 is lost if the sealability is poor during suction, and the suction amount does not satisfy a predetermined requirement. Therefore, in the present embodiment, with the above structure, the piston 302 can be compressed in the axial direction, and expanded in the radial direction, so as to achieve a better sealing effect, and thus, it is possible to ensure that the suction amount is accurate and reliable.

Referring to fig. 2 and 5, in one embodiment of the present invention, the connection end D20 includes a first cylindrical section 202, one end of the first cylindrical section 202 is connected to the push rod 20, and the other end of the first cylindrical section 202 is formed with a first annular shoulder 2021 protruding in the radial direction. The sliding sleeve 301 is sleeved on the first cylindrical section 202, and the one end of the sliding sleeve 301 is provided with a third annular blocking shoulder 3011 protruding inwards along the radial direction; the elastic member 303 is a spring, the spring is sleeved on the first cylindrical section 202, one end of the spring abuts against the first annular shoulder 2021, and the other end of the spring abuts against the third annular shoulder 3011.

That is, the spring is disposed between the first annular shoulder 2021 and the third annular shoulder 3011, and when the push rod 20 slides to a predetermined position in a direction away from the proximal end D10, the first annular shoulder 2021 and the third annular shoulder 3011 move relatively, so as to ensure that the spring can be compressed smoothly and reliably.

Advantageously, the connection end D20 further includes a second cylindrical section 203, one end of the second cylindrical section 203 is coaxially connected to the other end of the first cylindrical section 202, and the other end of the second cylindrical section 203 is formed with a second annular shoulder 2031 protruding in the radial direction.

The piston 302 has a socket hole, the socket hole includes a socket section and an inner block, one end of the socket section penetrates to one end of the piston 302 far away from the near end D10, the inner block is connected with the other end of the socket section and does not penetrate through the piston 302, and the diameter of the inner block is larger than that of the socket section. The second cylindrical section 203 is sleeved in the sleeve section, and the second annular shoulder 2031 is embedded in the inner block.

When the sliding sleeve 301 is contacted with the threaded sleeve fitting 40 and then the push rod 20 is rotated continuously, so that the push rod 20 continues to move to the predetermined position, the sliding sleeve 301 is blocked by the threaded sleeve fitting 40 and cannot slide continuously, and the push rod 20 continues to move, at this time, the second annular stop shoulder 2031 pulls the piston 302 to the distal end D11, and the piston 302 can be pressed to expand in the radial direction.

In this embodiment, the piston 302 and the connecting end D20 have the above-mentioned matching structure, so that the piston 302 can be reliably compressed, and the end of the piston 302 facing the proximal end D10 is not penetrated, so as to ensure that a good sealing performance is maintained between the piston 302 and the syringe 10. In addition, the assembly is simpler and more convenient.

Referring to fig. 2 to 3 and 5, in one embodiment of the present invention, the piston 302 includes a cylindrical body 3021 and an annular sealing portion 3022, the cylindrical body 3021 having the annular sealing portion 3022 formed on an outer circumferential surface of the cylindrical body 3021 to protrude outward in a radial direction of the cylindrical body 3021. An annular hole 3023 is formed in the cylindrical body 3021 around the axis of the cylindrical body 3021, and the annular hole 3023 is correspondingly positioned on the inner side of the annular sealing portion 3022, so that when the piston 302 is pressed, the annular hole 3023 is squashed, and the annular sealing portion 3022 is expanded radially outwards.

In this embodiment, the annular seal portion 3022 is pressed against the cylinder 10 to maintain a good sealing property. In addition, since the cylindrical body 3021 is internally provided with the annular hole 3023 around the axis of the cylindrical body 3021, the piston 302 can be compressed and expanded better, and a further enhanced sealing effect can be achieved.

Advantageously, the annular sealing portion 3022 and the annular hole 3023 are plural, the plural annular sealing portions 3022 are arranged at intervals along the axial direction of the cylindrical body 3021, and the plural annular holes 3023 correspond to the plural annular sealing portions 3022 one by one, so that the sealing is more reliable by the pressing fit of the plural annular sealing portions 3022 and the syringe 10.

Referring to fig. 1 and 3, in some embodiments of the present invention, the distal end D11 has two opposite ears 102, and each of the ears 102 is provided with a locking hole 1021. The threaded sleeve assembly 40 comprises a threaded sleeve 401, an end plate 402 and two buckles 403, wherein the threaded sleeve 401 can be inserted into or pulled out of the distal end D11, and the threaded sleeve 401 has the threaded hole. An end plate 402 is connected to one end of the threaded sleeve 401, and the threaded hole penetrates through the end plate 402. The two buckles 403 are oppositely arranged on the end plate 402, the two buckles 403 correspond to the two card holes 1021 one by one, and each buckle 403 is engaged with one corresponding card hole 1021 to relatively fix the threaded sleeve 401 and the distal end D11.

That is, the two fasteners 403 on the end plate 402 are engaged with the two fastening holes 1021 on the two ears 102 on the distal end D11, so as to fix the threaded sleeve fitting 40 to the syringe 10, and the fastening manner of the fasteners 403 is very convenient for installation and removal, and the fastening is reliable.

Referring to fig. 1 to 4, in some embodiments of the present invention, a needle 50 is further included, the needle 50 is detachably connected to the proximal end D10, and the needle 50 and the proximal end D10 form a seal by a sealing ring 51, so that the sealing effect between the needle 50 and the proximal end D10 can be improved by the sealing of the sealing ring 51.

It should be noted that, in the related art, the needle of the syringe is directly connected with the cylinder in a plug-in manner, and the sealing performance of this manner depends on the fitting degree of the peripheral wall of the joint between the needle and the cylinder, and obviously, the fitting degree of the peripheral wall of the joint between the needle and the cylinder may cause poor air tightness due to the processing precision. As described above, when the syringe is used for aspiration, the airtightness is strictly required to maintain a good negative pressure state. In this embodiment, adopt sealing washer 51 sealed, can reach better sealed effect, and then ensure that the suction effect is better, suction volume control is more accurate.

Referring to fig. 4, in one embodiment of the invention, proximal end D10 has a socket mouth 101 projecting axially. The needle 50 is provided with a needle cover 501, an L-shaped clamping groove 5011 is arranged on the peripheral wall of the needle cover 501, the L-shaped clamping groove 5011 comprises an axial section 5012a and a circumferential section 5012b, the axial section 5012a extends along the axial direction of the needle 50, one end of the axial section 5012a is opened to form an opening, and the circumferential section 5012b extends around the circumferential direction of the needle 50 and is communicated with the axial section 5012 a; an annular step surface is arranged in the needle head cover 501, and the sealing ring 51 is arranged on the annular step surface.

The outer peripheral surface of the adapter 101 is provided with a clamping part 1011, the clamping part 1011 extends along the radial direction of the adapter 101, when the needle cover 501 is sleeved with the adapter 101, the clamping part 1011 enters the axial segment 5012a from the opening, and after the needle cover 501 rotates around the axis of the adapter 101 by a preset angle, the clamping part 1011 enters the circumferential segment 5012b, so that the needle cover 501 is fixedly sleeved with the adapter 101, and the sealing ring 51 is pressed on the annular step surface by the end surface of the adapter 101.

When the needle 50 is connected with the needle cylinder 10, the clamping part 1011 on the sleeve joint mouth 101 on the needle cylinder 10 is aligned with the opening of the L-shaped clamping groove 5011 on the needle cover 501, then the needle cover 501 is oppositely inserted with the sleeve joint mouth 101, so that the clamping part 1011 enters the axial section 5012a of the L-shaped clamping groove 5011 from the opening and slides to the joint of the axial section 5012a and the circumferential section 5012b, at the moment, the needle cover 501 is rotated, and the clamping part 1011 slides into the other end of the circumferential section 5012b, thus, the needle 50 and the needle cylinder 10 can be quickly connected and fixed. Furthermore, during this process, the sealing ring 51 is pressed by the end face of the adapter 101 against an annular step face in the needle cover 501, so that a reliable sealing effect is formed between the adapter 101 and the needle cover 501.

In this embodiment, the needle 50 and the barrel 10 can be conveniently and quickly connected and disconnected, and the sealing ring 51 is compressed, so as to ensure a higher sealing grade between the needle 50 and the barrel 10.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A screw-type syringe, comprising:

a barrel having a distal end and a proximal end;

2. The screw-type injector of claim 1, wherein the piston assembly comprises:

the elastic piece is arranged between the sliding sleeve and the push rod;

3. The threaded syringe of claim 2, wherein the piston is configured to be compressible, and when the plunger slides away from the proximal end to a predetermined position, the piston abuts against the other end of the sliding sleeve and is pressed by the pressure applied by the connecting end to expand radially outwards, so that the outer peripheral surface of the piston is tightly sealed with the syringe barrel, wherein the pressure is along the axial direction of the syringe barrel and towards the distal end.

4. The screw-type injector of claim 3, wherein the connection end comprises:

5. The screw-type injector of claim 4, wherein said connection end further comprises:

6. The screw-type injector according to claim 5, wherein the piston comprises:

a cylindrical body;

7. The screw-type injector according to claim 6, wherein the annular sealing portion and the annular hole are provided in plural, the plural annular sealing portions are provided at intervals in the axial direction of the cylindrical body, and the plural annular holes correspond to the plural annular sealing portions one to one.

8. The screw-type injector according to claim 1, wherein said distal end has two opposing ears, each of said ears having a snap-hole;

the threaded sleeve fitting comprises:

9. The screw-type injector according to claim 1, further comprising:

10. The screw-type injector according to claim 9, wherein said proximal end has a spigot projecting in an axial direction;