CN212141083U

CN212141083U - Syringe and push rod assembly thereof

Info

Publication number: CN212141083U
Application number: CN202020267957.3U
Authority: CN
Inventors: 邢玉珊; 孙小峰; 武玉娟; 王海林
Original assignee: Shandong Weigao Prefills Pharmaceutical Packaging Co Ltd
Current assignee: Shandong Weigao Prefills Pharmaceutical Packaging Co Ltd
Priority date: 2020-03-06
Filing date: 2020-03-06
Publication date: 2020-12-15
Anticipated expiration: 2030-03-06

Abstract

The utility model discloses a push rod assembly, including the push rod with connect in the terminal piston of push rod, the push rod with the piston connects soon through the screw thread, just the push rod with still be equipped with circumference positioning mechanism between the piston. The utility model also discloses a syringe of including above-mentioned push rod subassembly. The utility model provides a push rod assembly can effectively avoid the relative push rod of piston to take place axial displacement, guarantees that the piston feeds the accuracy of volume and injection medicine volume inerrably.

Description

Syringe and push rod assembly thereof

Technical Field

The utility model relates to the technical field of medical equipment, in particular to push rod assembly. The utility model discloses still relate to a syringe that has this push rod subassembly.

Background

Syringes are common consumable medical devices. The piston is divided into a buckling type and a thread type according to the matching mode of the piston and the push rod. Among them, the screw type syringe is widely used in various sizes of syringes because it can endure a large force. The predetermined amount injector judges the injection amount of the medicine by the feed distance of the push rod. The piston and the push rod can rotate freely to a certain degree due to threaded matching, so that the piston generates axial displacement relative to the push rod, and inaccurate medicine feeding is caused in the using process.

Therefore, how to avoid the axial displacement of the piston relative to the push rod becomes a technical problem to be solved by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a push rod assembly, this push rod assembly can effectively avoid the relative push rod of piston to take place axial displacement, guarantees that the piston feeds the accuracy of volume and injection medicine volume errorless. Another object of the present invention is to provide a syringe including the above push rod assembly.

In order to achieve the above object, the utility model provides a push rod assembly, including the push rod with connect in the terminal piston of push rod, the push rod with the piston connects through the screw thread soon, just the push rod with still be equipped with circumference positioning mechanism between the piston.

Optionally, the push rod includes a stopping disc for stopping the piston, a stud disposed on the upper end surface of the stopping disc for connecting the piston, and a cross bar disposed on the lower end surface of the stopping disc, and an internal threaded hole matched with the stud is disposed at the bottom of the piston.

Optionally, the circumferential positioning mechanism includes a ratchet positioning protrusion disposed on an upper end surface of the stopping disc, and a ratchet groove disposed on a circumferential portion of the internal threaded hole and engaged with the ratchet positioning protrusion.

Optionally, an annular groove is formed in the periphery of the ratchet wheel positioning protrusion, and a positioning protrusion used for being clamped and embedded in the annular groove is arranged at the bottom of the piston.

Optionally, the ratchet wheel positioning protrusion is locked in a counterclockwise direction with respect to the ratchet wheel groove.

Optionally, the positioning protrusion is a positioning column uniformly arranged along the circumferential direction of the bottom of the piston.

The utility model also provides a syringe, including the injection tube and as above the push rod subassembly, the piston with the inner wall laminating of injection tube is sealed.

Compared with the prior art, the utility model provides a push rod assembly, including push rod and piston, connect through the screw-thread fit between push rod and the piston, guaranteed the reliability of connection, avoid the piston to slip relative to the push rod; furthermore, a circumferential positioning mechanism is arranged between the piston and the push rod, and after the piston and the push rod are connected in place, the piston and the push rod are fixed by the circumferential positioning mechanism along the circumferential direction of the piston and the push rod, so that the piston and the push rod are prevented from rotating in the circumferential direction, the axial displacement of the piston relative to the push rod is avoided, and the feeding precision of the injector and the precision of the amount of the injected medicine are ensured.

Drawings

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

Fig. 1 is a schematic view of a syringe provided in an embodiment of the present invention;

FIG. 2 is a pictorial view of the piston of FIG. 1;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a schematic view of the putter of FIG. 1;

FIG. 5 is an enlarged partial schematic view of FIG. 4;

FIG. 6 is a cross-sectional view of FIG. 5;

fig. 7 is a schematic view of a putter assembly according to another embodiment of the present invention.

Wherein:

1-push rod, 11-stud, 12-stop disc, 13-cross bar, 2-piston, 3-injection tube, 4-ratchet wheel positioning projection, 5-ratchet wheel groove, 6-ring groove and 7-positioning projection.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In order to make the technical field of the present invention better understand, the present invention will be described in detail with reference to the accompanying drawings and the detailed description.

Referring to fig. 1 to 7, fig. 1 is a schematic view of an injector according to an embodiment of the present invention, fig. 2 is a schematic view of a piston in fig. 1, fig. 3 is a top view of fig. 2, fig. 4 is a schematic view of a push rod in fig. 1, fig. 5 is a partially enlarged schematic view of fig. 4, and fig. 6 is a cross-sectional view of fig. 5; fig. 7 is a schematic view of a putter assembly according to another embodiment of the present invention.

The utility model provides a push rod assembly includes

push rod

1 and 2 two parts of piston, and this push rod assembly comes to install in the inside of the injection tube 3 of syringe, and the laminating through 3 inner walls of piston 2 and injection tube forms sealedly, with the help of push rod 1 promotes piston 2 and feeds along the axial of injection tube 3, extrudees the injection for the patient with 3 interior medicine of injection tube. In order to avoid circumferential displacement of the piston 2 and the push rod 1, the push rod assembly fixes the piston 2 and the push rod 1 in a mode that the piston 2 and the push rod 1 are screwed in a thread manner and are combined with a circumferential positioning mechanism. After the piston 2 rotates in place relative to the push rod 1, the circumferential positioning mechanism relatively fixes the piston 2 and the push rod 1 along the circumferential direction of the piston and the push rod, the piston 2 cannot be screwed out of the push rod 1, circumferential displacement is avoided, and feeding reliability is guaranteed.

The push rod assembly provided by the present invention will be described in more detail with reference to the accompanying drawings and specific embodiments.

In the embodiment provided by the present invention, the push rod 1 of the push rod assembly is usually made of plastic material, and the piston 2 is usually a rubber plug. The push rod 1 comprises a disc-shaped stop disc 12, and the stop disc 12 is used for being contacted and abutted with the bottom surface of the piston 2 to play a role in stopping and limiting the piston 2. The center of the upper end face of the stop disc 12 is fixedly connected with a stud 11, the bottom face of the piston 2 is provided with an internal thread hole matched and screwed with the stud 11, and the piston 2 and the push rod 1 are connected and fixed by screwing the stud 11 into the internal thread hole of the piston 2. At this time, the bottom surface of the piston 2 just butts against the upper end surface of the stop disc 12; the lower end face of the stop disc 12 is fixedly connected with a cross bar rod 13, the cross bar rod 13 is a rod with a cross section and is used for pushing the stop disc 12 of the rod 1 and the piston 2 to feed, and the tail end of the cross bar rod 13 is fixedly connected with a disc for pushing and pressing fingers. The cross bar 13, the stop disc 12 and the stud 11 are usually formed by integral injection molding.

In the above embodiment, the circumferential positioning mechanism mainly includes the ratchet positioning protrusion 4 provided on the upper end surface of the stop disc 12, a plurality of ratchets are uniformly provided in the circumferential direction of the ratchet positioning protrusion 4, the bottom of the piston 2, more specifically, the circumferential portion of the internal thread hole is provided with the ratchet groove 5, the ratchet groove 5 has a plurality of ratchet grooves corresponding to the ratchets of the ratchet positioning protrusion 4 one by one, when the piston 2 is screwed in place, the ratchet positioning protrusion 4 is just located in the ratchet groove 5, the circumferential fixation of the piston 2 relative to the stop disc 12 is realized by the cooperation of the ratchets and the ratchet grooves, the rotation and slippage of the piston 2 relative to the push rod 1 are avoided, and thereby the axial displacement of the piston 2 is limited.

Particularly, the ratchet wheel positioning protrusion 4 and the ratchet wheel groove 5 are matched and locked in a one-way mode, when the piston 2 is screwed clockwise, the ratchet wheel positioning protrusion 4 can rotate clockwise relative to the ratchet wheel groove 5, after the ratchet wheel positioning protrusion 4 is assembled in place relative to the ratchet wheel groove 5, the ratchet wheel positioning protrusion 4 is locked in the anticlockwise direction relative to the ratchet wheel groove 5, the ratchet wheel positioning protrusion 4 and the ratchet wheel groove 5, namely the piston 2 and the push rod 1 cannot rotate circumferentially relative to each other, and axial feeding of the piston 2 relative to the push rod 1 is avoided.

In order to further improve the bonding seal between the bottom of the piston 2 and the push rod 1, namely the stop disc 12, the circumferential part of the ratchet wheel positioning bulge 4 is provided with an annular groove 6, and the bottom of the piston 2 is provided with a positioning bulge 7 for being embedded into the annular groove 6. The bottom of the piston 2 is tightly attached to the push rod 1 through the matching of the positioning bulge 7 and the annular groove 6.

The positioning protrusion 7 can be a columnar positioning protrusion 7, that is, a positioning column, and the positioning columns are uniformly arranged along the circumferential direction of the bottom of the piston 2; in addition, the positioning protrusion 7 may also be an annular rib with the axis of the piston 2 as the center, the annular rib protrudes downward relative to the bottom surface of the piston 2, and the thickness of the protrusion is equal to the depth of the annular groove 6. The annular groove 6 and the positioning protrusion 7 are matched to meet the circumferential rotation of the piston 2 relative to the push rod 1 in the installation process of the piston 2, and the piston 2 and the push rod 1 can be matched to be tightly attached to the stop disc 12 of the push rod 1 after the piston 2 and the push rod 1 are screwed in place.

In an embodiment, the circumferential positioning mechanism may further include a plurality of protrusions disposed at the bottom of the piston 2 in the circumferential direction and a plurality of grooves disposed at the upper end surface of the stopping disc 12, and the protrusions and the grooves are disposed in a one-to-one correspondence in number and size, and also in a one-to-one correspondence in position relative to the axis of the stopping disc 12 or the piston 2. The arch specifically can be crown shape arch, and recess and protruding shape cooperation connect installation piston 2 and push rod 1 soon, and protruding laminating stop disc 12's non-groove area time, protruding upwards compression, after piston 2 and push rod 1 installation target in place, protruding recovery deformation is in the recess just, realizes the fixed of 1 circumference of piston 2 relative push rod through the cooperation of protruding and recess, avoids the rotatory slippage of piston 2.

The circumferential positioning mechanism can be not only as described above, but also in the shape as shown in fig. 7, at this time, the circumferential relative fixation of the piston 2 and the stopping disc 12 is realized by arranging the positioning ratchets on the circumferential side of the stopping disc 12 to be matched with the ratchet grooves 5 of the piston 2, and meanwhile, the stopping disc 12 is completely embedded in the ratchet grooves 5 of the piston 2, so that the two are good in attaching and sealing effects.

The utility model provides a syringe, which comprises an injection tube 3 and a push rod component described in the above embodiment, wherein a piston 2 of the push rod component is tightly attached to the inner wall of the injection tube 3 to seal liquid medicine; other parts of the syringe may be referred to in the art. The piston 2 and the push rod 1 are connected in a screwing mode and combined with a circumferential positioning mechanism, so that the connection reliability of the piston 2 and the push rod 1 is guaranteed, the piston 2 is prevented from rotating relative to the push rod 1 and then from circumferentially displacing relative to the push rod 1, and the feeding precision of the injector is guaranteed.

It is noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity from another entity without necessarily requiring or implying any actual such relationship or order between such entities.

The syringe and the push rod assembly thereof provided by the present invention are described in detail above. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.

Claims

1. The push rod assembly is characterized by comprising a push rod (1) and a piston (2) connected to the tail end of the push rod (1), wherein the push rod (1) is screwed with the piston (2) through threads, and a circumferential positioning mechanism is further arranged between the push rod (1) and the piston (2).

2. The push rod assembly according to claim 1, wherein the push rod (1) comprises a stop disc (12) for stopping the piston (2), a stud (11) arranged on the upper end surface of the stop disc (12) and used for connecting the piston (2), and a cross bar (13) arranged on the lower end surface of the stop disc (12), and an internal threaded hole matched with the stud (11) is formed in the bottom of the piston (2).

3. The tappet assembly of claim 2, wherein the circumferential positioning mechanism comprises a ratchet positioning protrusion (4) provided on an upper end surface of the stopper disc (12) and a ratchet groove (5) provided on a circumferential portion of the female screw hole and engaged with the ratchet positioning protrusion (4).

4. The push rod assembly as claimed in claim 3, wherein the ratchet wheel positioning protrusion (4) is provided with an annular groove (6) at the periphery thereof, and the piston (2) is provided with a positioning protrusion (7) at the bottom thereof for being inserted into the annular groove (6).

5. A push rod assembly according to claim 3, wherein the ratchet positioning protrusion (4) locks against the counter clockwise direction of the ratchet groove (5).

6. The push rod assembly according to claim 4, characterized in that the positioning protrusions (7) are positioning columns uniformly arranged along the circumference of the bottom of the piston (2).

7. Syringe, characterized in that it comprises a barrel (3) and a tappet assembly according to any one of claims 1 to 6, the piston (2) being in close sealing contact with the inner wall of the barrel (3).