CN110898293B - Syringe piston, piston assembly and syringe - Google Patents

Abstract

The application discloses syringe piston, piston assembly and syringe, including the piston body and detain rather than butt joint complex piston, the piston body has the rear end face, the concave pilot hole that is equipped with of rear end face, the pore wall of pilot hole is equipped with the first position of detaining of at least twice, on the butt joint direction, each way first detain the position by setting up to preceding interval in proper order backward, the piston is detained and is equipped with at least twice second and detains the position, each way the second is detained position and each way the first position one-to-one of detaining, when piston body and piston are detained the butt joint and are targetting in place, each way the first position of detaining is detained rather than corresponding the second is detained the position, just the pore wall of pilot hole with the space has between the preceding terminal surface that the piston was detained. The syringe piston reserves a certain gap as a space avoiding position in the assembling stage so as to facilitate assembling, and when the push rod is assembled, the piston body and the piston buckle realize self-locking through at least two buckle positions, so that the inclination of the syringe piston when the syringe piston absorbs liquid medicine can be effectively reduced or avoided.

Description

Syringe piston, piston assembly and syringe

Technical Field

The invention relates to the technical field of medical instruments, in particular to a medical injector and a piston thereof.

Background

Chinese utility model patent entitled "plunger, piston assembly and syringe", publication No. CN205007383U discloses a piston assembly, as shown in fig. 1, the plunger has a spacing arm 221 with fixed width, and the initial position relative to the high-pressure syringe push rod can shift with different degrees along with the aging of the device, resulting in that the spacing arm 221 with fixed width can not match with the shifted high-pressure syringe push rod, resulting in the situation of unable assembly. Moreover, the position of each high-pressure injector push rod is not constant, and the high-pressure injectors produced in different batches have different errors, so that the fixed limiting arm 221 cannot meet all the existing high-pressure injectors, although the width of the limiting arm 221 is also provided with a size allowance for assembling the high-pressure injector push rods, the size design at the present stage is usually that the allowance size is smaller than the size of the displacement of the high-pressure injector push rods, if the allowance size is increased, the piston and the high-pressure injector push rods are assembled loosely, so that the situation that the liquid medicine sucked by the piston is deflected and the medicine sucking amount is not consistent with the nominal capacity of the needle cylinder occurs.

Disclosure of Invention

The invention provides a novel syringe piston.

The invention provides a piston body of an injector, which is provided with a rear end face, wherein an assembly hole is concavely arranged on the rear end face, the hole wall of the assembly hole is provided with at least two first buckling positions, and in the axial direction of the piston body, the first buckling positions are sequentially arranged at intervals from back to front. The first buckling positions can be parallel to each other.

The first buckling position is concavely arranged on the hole wall and surrounds the axis. That is, the first catch may be an annular groove. The first buckling position can also be arranged on the hole wall in a protruding mode.

The utility model provides a with piston body butt joint complex piston buckle, include the piston and detain the body and hang the platform, the outer peripheral face that the body was detained to the piston is equipped with at least twice second and detains the position on the axis direction that the body was detained to the piston, each way the second is detained the position and is set up by back preceding interval in proper order, hang the platform and locate the rear end face that the body was detained to the piston. The second buckling positions can be parallel to each other.

And expansion joints extend from the front end face to the rear end face of the piston buckle body, and the expansion joints disconnect the second buckle positions. The expansion joint has a certain width, and can be positioned at the central position of the piston buckle body, namely the expansion joint can pass through the axis of the piston buckle body.

The utility model provides an injector piston, includes the piston body and detains rather than butt joint complex piston, the piston body has the rear end face, the concave pilot hole that is equipped with of rear end face, the pore wall of pilot hole is equipped with the first position of detaining of at least twice, on the butt joint direction, each way the first position of detaining is by setting up to preceding interval in proper order backward, the piston is detained and is equipped with at least twice second and detains the position, each way the second is detained the position and is respectively the first position one-to-one of detaining, when piston body and piston detained the butt joint and target in place, each way the second is detained the position and is detained rather than corresponding the first position of detaining, just the pore wall of pilot hole with the piston detains and has the space between the preceding terminal. Each first buckling position is provided with only one second buckling position correspondingly matched with the first buckling position.

The piston buckle comprises a piston buckle body and a hanging table, the second buckle position is arranged on the outer peripheral surface of the piston buckle body, an expansion joint extends out from the front end surface to the rear end surface of the piston buckle body, and the expansion joint is disconnected with each second buckle position. The gap is formed between the front end face of the piston buckle body and the hole wall of the assembling hole.

The rear end face of the piston buckle body is provided with a self-locking step with a guide inclined plane.

The first buckling position and the second buckling position are respectively provided with two parts, the first buckling position is convexly arranged or concavely arranged on the hole wall of the assembling hole, and the second buckling position is convexly arranged on the peripheral surface of the piston buckle body.

The syringe piston assembly comprises a push rod, a rubber plug and the syringe piston, wherein the rubber plug is sleeved on the piston body, and the push rod is hung on the hanging table. The outer peripheral surface of the piston body is concavely provided with an assembly groove, and the rubber plug is embedded and fixed in the assembly groove. The assembling direction of the push rod can be vertical to the butt joint direction of the piston buckles, and after the push rod is assembled in place along the assembling direction, each second buckling position buckles the corresponding first buckling position.

The piston buckle is provided with a first position and a second position, when the push rod is not assembled, the piston buckle can be positioned at the first position, and the second buckle position is in butt fit with the corresponding first buckle position; after the push rod is assembled in place, the piston buckle is located at the second position, and the second buckle position is in buckle fit with the corresponding first buckle position, so that the self-locking of the piston body and the piston buckle is realized. When the first position is reached, the second fastening position is abutted against the corresponding first fastening position, that is, in the butt joint direction, the second fastening position can be positioned below the corresponding first fastening position, and the second fastening position does not fasten the first fastening position.

An injector comprises a syringe and the injector piston assembly, wherein the injector piston assembly is connected with the syringe in a sealing and sliding way. The rubber plug of the syringe piston component is hermetically and slidably connected with the syringe.

The invention has the beneficial effects that: the syringe piston reserves a certain gap as a space avoiding position in the assembling stage so as to facilitate assembling, and when the push rod is assembled, the piston body and the piston buckle realize self-locking through at least two buckle positions, so that the inclination of the syringe piston when the syringe piston absorbs liquid medicine can be effectively reduced or avoided.

Drawings

FIG. 1 is an exploded perspective view of the syringe plunger of the present embodiment;

fig. 2 is a schematic top view of the plunger clasp of the present embodiment;

FIG. 3 is a cross-sectional view of the syringe plunger and syringe piston prior to assembly;

FIG. 4 is an enlarged partial schematic view of FIG. 3;

FIG. 5 is a cross-sectional view of the syringe plunger and syringe piston after assembly;

fig. 6 is a partially enlarged schematic view of fig. 5.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings.

As shown in fig. 1 to 6, a syringe piston comprises apiston body 1 and apiston buckle 2 in butt fit with the piston body. Thepiston body 1 is provided with arear end face 15, and therear end face 15 is concavely provided with anassembly hole 16 matched with the piston buckle. The hole wall of theassembly hole 16 is provided with at least twofirst buckling positions 13, and in the butt joint direction, thefirst buckling positions 13 are sequentially arranged at intervals from back to front. Thepiston buckle 2 is provided with at least twosecond buckling positions 21, in the axial direction of the piston body, thesecond buckling positions 21 are sequentially arranged at intervals from back to front, and thesecond buckling positions 21 correspond to thefirst buckling positions 13 one by one.

After thepiston body 1 and thepiston buckle 2 are butted in place, thepiston buckle 2 is plugged into theassembly hole 16 of the piston body, and eachsecond buckle position 21 buckles the correspondingfirst buckle position 13.

For a syringe piston, thepiston body 1 and thepiston button 2 may be coaxial. The axial direction of thepiston body 1 may be the butt joint direction a of thepiston buckle 2. After thepiston body 1 and thepiston buckle 2 are butted in place, agap 14 is formed between thefront end surface 26 of thepiston buckle 2 and the hole wall of theassembly hole 16, so that the piston buckle has certain movement allowance in the butting direction; in the direction opposite to the docking direction, thepiston catch 21 is locked with thepiston body 1, i.e. the piston catch cannot be released from the piston body in the opposite direction.

As shown in fig. 1 to 6, a syringe piston comprises apiston body 1 and apiston buckle 2 which are in butt fit. The outerperipheral surface 11 of thepiston body 1 is concavely provided with anassembly groove 12, theassembly groove 12 is used for installing a rubber plug, and the rubber plug is used for being sealed and in sliding fit with the needle cylinder. Theback end face 15 of thepiston body 1 is concavely provided with amounting hole 16, and themounting hole 16 is used for matching with thepiston buckle 2. The hole wall of theassembly hole 16 is concavely provided with two circles offirst buckling positions 13, and the two circles offirst buckling positions 13 are arranged at intervals in the butt joint direction. Thefirst fastening portion 13 may be recessed or protruded on the wall of the mounting hole. Thefirst fastening portion 13 may be a ring.

Thepiston buckle 2 comprises apiston buckle body 27 and a hangingplatform 23 positioned at the rear of the piston buckle body. The outerperipheral surface 22 of the piston buckle body is provided with twosecond buckling positions 21, thesecond buckling positions 21 are convexly arranged on the outerperipheral surface 22, and thesecond buckling positions 21 can encircle the axis of the piston buckle body. Anexpansion joint 24 is formed by extending from the front end surface to the rear end surface of thepiston buckle body 27, and eachsecond buckle position 21 is divided into two sections which are not communicated with each other by theexpansion joint 24, namely, the expansion joint is equivalent to the disconnection of each second buckle position. The back end face of the piston buckle body is provided with a self-lockingstep 25 with a guide inclined plane, and the guide inclined plane extends downwards towards the axis of the piston buckle body. The hangingplatform 23 is used for hanging and matching with thepush rod 3.

After thepiston buckle 2 and thepiston body 1 are butted in place, eachsecond buckling position 21 buckles each correspondingfirst buckling position 13, and agap 14 is formed between the front end surface of the piston buckle body and the wall of the assembling hole. For each first buckling position, the first buckling position can be in a complete ring shape or can be formed by a plurality of separately arranged buckling positions. For each second buckling position, the second buckling position can be in a complete ring shape or can be formed by a plurality of separately arranged buckling positions. The cross section of the second buckling position can be triangular or other shapes capable of realizing self-locking.

As shown in fig. 1 to 6, a piston assembly includes a syringe piston, apush rod 3 and a rubber plug. The syringe piston is including butt jointcomplex piston body 1 andpiston buckle 2, and the outerperipheral face 11 ofpiston body 1 is recessed and is formedannular assembly groove 12, and the plug embedding is fixed in this assembly groove. The rear end face 15 of thepiston body 1 is recessed to form afitting hole 16, and thefitting hole 16 is used for matching with thepiston buckle 2. The wall of theassembly hole 16 is provided with two first bucklingpositions 13, and the two first bucklingpositions 13 are parallel to each other and encircle the axis of the piston body.

Thepiston buckle 2 comprises apiston buckle body 27 and a hanging table 23 located behind the piston buckle body, thepiston buckle body 27 can be matched with thepiston body 1, and the hanging table 23 can be matched with theinjector push rod 3. Two rings of second bucklingpositions 21 are convexly arranged on the outerperipheral surface 22 of the piston buckle body. The middle part of the piston buckle body is provided with anexpansion joint 24, in the axial direction of the piston buckle, theexpansion joint 24 extends from the front end surface to the rear end surface of the piston buckle body, and theexpansion joint 24 disconnects eachsecond buckle position 21. The self-lockingstep 25 of the body of the plunger buckle has a guide slope with a gradually decreasing outer diameter. The hanging table 23 is arranged below the rear end face of thepiston buckle 2. The hanging table 23 is substantially in the shape of an inverted T. Thepush rod 3 can be matched with thepiston buckle 2, thepush rod 3 is provided with a hanginggroove 31, and the hangingplatform 23 is matched with the hanginggroove 31 in a hanging mode after the push rod is assembled in place.

During the assembly, earlier along butt joint direction A, detain thepiston 2 and thepilot hole 16 butt joint ofpiston body 1, when the piston detained 2 butt joint and removed to the primary importance, the second detainedposition 21 and the first cooperation of detaining 13 butt joints, and the piston detains the terminal surface of body auto-lock step 25 and is less than the rear end face 15 of piston body. Then, thepush rod 3 is assembled into the injector piston along the assembling direction B, in the assembling process, thepush rod 3 extrudes the self-lockingstep 25, thepiston buckle 2 moves upwards along the butt joint direction A until the second bucklingposition 21 buckles the first bucklingposition 13, at the moment, the end surface of the self-lockingstep 25 is flush with therear end surface 15, and the hanging table 23 of the piston buckle is in hanging fit with the hanginggroove 31 of the push rod.

An injector comprises a syringe and the injector piston assembly, wherein the injector piston assembly is hermetically and slidably matched with the syringe.

For the injector piston, before the injector piston is assembled with theinjector push rod 3, thepiston buckle 2 is at a first position, and asecond buckle position 21 of the piston buckle is in butt fit with afirst buckle position 13 of the piston body; after the assembly with theinjector push rod 3 is completed, thepiston buckle 2 moves to a second position through the extrusion action of theinjector push rod 3, and thepiston buckle 2 and thepiston body 1 are automatically locked; because a certain gap exists between thepiston buckle 2 and thepiston body 1, the effect of matching injectors of various models can be achieved. The latchingstep 25 of the plunger catch has a guide ramp to push the delivery plunger catch forward into the second position by the syringe plunger. The piston body is provided with anassembly groove 12 for assembling the rubber plug to form an injector system matched with the injector syringe.

The syringe piston is provided with at least two buckling positions, the first buckling position is used for assembling the piston buckle and the piston body, the syringe piston is extruded when being installed in the syringe push rod, the piston buckle is pressed into the second position through the stress of the guide inclined plane of the self-locking step, and the whole syringe piston and the syringe push rod are in a locking state and are not loosened. And for the guide inclined plane, the piston buckle is gradually pushed to move to the second position by the stress of the self-locking step along with the loading of the injector push rod. The piston buckle is provided with a hanging table which has the function of pulling the whole piston to suck liquid medicine backwards after being assembled with the hanging groove of the injector push rod. The middle position of the piston buckle is provided with an expansion joint, so that the piston buckle can be deformed in a certain expansion mode in the moving process of the piston buckle, and the dislocation size compensation generated when the piston buckle is pushed into the second position from the first position can be realized.

The foregoing is a more detailed description of the present invention that is presented in conjunction with specific embodiments, and the practice of the invention is not to be considered limited to those descriptions. It will be apparent to those skilled in the art that a number of simple derivations or substitutions can be made without departing from the inventive concept.

Claims (5)

1. A syringe piston is characterized by comprising a piston body and a piston buckle in butt joint with the piston body, wherein the piston body is provided with a rear end face, the rear end face is concavely provided with an assembling hole, the hole wall of the assembling hole is provided with at least two first buckling positions, each first buckling position is sequentially arranged from back to front at intervals in the butt joint direction, the piston buckle is provided with at least two second buckling positions, each second buckling position corresponds to each first buckling position one by one, when the piston body and the piston buckle are in butt joint in place, each second buckling position buckles the corresponding first buckling position, and a gap is formed between the hole wall of the assembling hole and the front end face of the piston buckle; the first buckling position is an annular body, and the second buckling position is an annular body surrounding the axis of the piston buckle body; the piston buckle comprises a piston buckle body and a hanging table, the second buckle position is arranged on the outer peripheral surface of the piston buckle body, an expansion joint extends out from the front end surface to the rear end surface of the piston buckle body, and the expansion joint is disconnected with each second buckle position.

2. The syringe plunger of claim 1, wherein the rear end face of the plunger button body is provided with a self-locking step having a guide slope.

3. The syringe plunger of claim 1, wherein there are two first snap locations and two second snap locations, the first snap location is disposed convexly or concavely on the wall of the assembly hole, and the second snap location is disposed convexly on the outer circumferential surface of the plunger body; the first catch encircles the axis of the piston body.

4. An injector piston assembly comprises a push rod and a rubber plug, and is characterized by further comprising an injector piston according to any one of claims 1 to 3, wherein the rubber plug is sleeved on the piston body, and the push rod is hung on the hanging table; before the piston buckle is assembled with the push rod, the piston buckle is located at a first position, and a second buckling position of the piston buckle is in butt fit with a first buckling position of the piston body; after the piston buckle and the push rod are assembled, the piston buckle moves to the second position through the extrusion effect of the push rod, and the piston buckle and the piston body are automatically locked.

5. An injector comprising a barrel and further comprising the injector piston assembly of claim 4, said injector piston assembly being sealingly and slidably connected to said barrel.

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