CN1191101C - Improved external safety syringe - Google Patents

Abstract

An improved external-mounted safety syringe is characterized in that a plurality of convex ribs are longitudinally arranged on the wall of a needle sleeve hole of a needle sleeve part at the front end of the syringe, a plurality of convex ribs are longitudinally arranged on the periphery of a needle stem part corresponding to a needle tool, when the needle stem part is fastened on the needle sleeve part and a hollow needle is externally and rotatably combined on the needle stem part, the convex ribs of the needle stem part are clamped with the convex ribs of the needle sleeve part and are not twisted, and the hollow needle can be smoothly and rotatably mounted; and the end of the piston rod adjacent to the piston is provided with a ratchet hook, when the piston rod is installed in the needle cylinder and the piston rod is longitudinally pulled back, the ratchet hook is blocked on a flange ring at the rear part of the needle cylinder, so that the piston rod and the injected needle tool coupled on the piston can not be pulled out. Has the efficacy that after the injection is finished, the retractable needle device can retreat into the needle cylinder and automatically deflect without repeatedly extending forwards to prick people.

Description

Improved external safety syringe

technical field

The present invention relates to an improved safety needle cylinder with external installation.

Background technique

The Chinese Taiwan utility model patent No. 84209505 (approval announcement on August 1, 1986, publication number is 312154) of the inventor's previous application is titled as "safety syringe that contains an externally mounted injection needle and retracts to be automatically deflected" ", after the injection is completed, the safety syringe can retract and the injection needle will automatically deflect when entering the syringe, and will no longer stick out and stab people. Its main flaws are:

When installing the injection needle, in order to prevent the screwed needle stem from being rotated together, a shallow dimple and two flanges are provided in the shoulder of the syringe to block the cylindrical part of the needle stem However, when the injection liquid is exhausted, the liquid medicine in this shallow recess is not compressed by the piston to form a "pool of stagnant water", which cannot be injected into the needle, resulting in a waste of liquid medicine.

Contents of the invention

Aiming at the above-mentioned defects, the inventors conducted research and improvement, and created the technical solution of the present invention.

The purpose of the present invention is to provide an improved external safety needle cylinder, through the needle sleeve hole wall of the needle sleeve at the front end of the needle cylinder, a plurality of protruding ribs are arranged vertically, and corresponding to the outer periphery of the needle stem of the needle. There are many protruding ribs vertically arranged on the upper part, and the needle stem is fastened to the needle cover. The hollow needle can be screwed smoothly without being twisted; and there is a ratchet hook on the end of the piston rod adjacent to the piston. After installing the piston rod in the needle barrel, pull back the piston rod longitudinally. The part will be locked on the flange ring at the back of the syringe, so that the piston rod and the needle coupled to the piston will not be pulled out. After the injection is completed, the needle can be retracted and retracted into the syringe. It will automatically deflect and no longer stretch forward. human purpose.

The object of the present invention is achieved in the following way: an improved external safety syringe, comprising a needle cover at the front end of the syringe device; the needle is installed on the syringe device, and the needle includes a hollow needle, a The needle stem part and a buckle head, the needle stem part is buckled in the needle cover part, the hollow needle is externally mounted and screwed on the needle stem part; the piston device is slid in the syringe device, and a deflection is recessed on the piston The socket and buckle the buckle head of the needle is characterized in that: the hole wall of the needle sleeve hole of the needle sleeve is provided with a plurality of needle sleeve protrusion ribs; the needle stem is provided with a plurality of needle stem protrusion ribs It is longitudinally arranged on the outer periphery of the needle stem and engages with the needle sleeve protruding rib in the needle sleeve hole.

The stem part of the needle is provided with a tightening ring which is arranged on the stem part of the needle and stops at the rib end of the protruding rib of the needle sleeve. The needle stem part is provided with a flange plate which is connected to the rear end of the needle stem part and fastened in a recess of the needle sheath part. The front end of the piston rod of the piston device is connected with a disc, the front edge of which is arc-shaped, and at least one ratchet hook is provided along the circumference of the disc, and a flange ring is provided in the syringe at the rear edge of the syringe device. . The ratchet hook is a disc-shaped ratchet hook.

Further description will be given below in conjunction with preferred embodiments and accompanying drawings.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a needle stem and a syringe of the present invention.

Fig. 2 is a schematic cross-sectional view of the combination of the stem part of the needle cylinder of the present invention.

Fig. 3 is a schematic cross-sectional view of the buckle head of the needle with the piston fastened when the injection of the present invention is completed.

Fig. 4 is a schematic diagram of the self-deflecting needle after retraction of the present invention.

Fig. 5 is a schematic diagram of preventing the piston rod from being pulled out according to the present invention.

Fig. 6 is a schematic view of the ratchet hook of the present invention.

Detailed ways

Referring to FIG. 1-FIG. 6 , the present invention includes a needle 2 and a piston device 3 slidingly engaged in a syringe device 1 . The syringe device 1 comprises: a barrel interior 10 of a syringe part 11 for containing injection liquid, a needle cover part 12 is arranged at the front end of the syringe part 11, and a needle cover hole 12 is arranged in it, a shoulder 13 between the syringe part 11 and the needle cover part 12, a syringe rear flange 14 is arranged on the rear edge of the syringe part, and a flange ring 15 is arranged inside the cylinder 10 and the rear edge is adjacent to the rear flange 14.

The needle cover hole 12a of the needle cover part 12 is provided with a plurality of needle cover protrusion ribs 12b vertically on the hole wall, and a flange disc recess 12c is recessed at the rear edge adjacent to the needle cylinder shoulder 13 .

The needle tool 2 includes: a coupling sheath 21a connected to the rear of a hollow needle 21, the inner ring of which is provided with a female thread 21b; The flange plate 22a is connected to the rear end of the needle stem part 22 to fasten a recess 12c in the needle cover part. As shown in FIG. The rib 12b of the needle sleeve is engaged with the needle sleeve hole, and a tightening ring 22C is arranged on the needle stem part 22 to stop at the rib end of the needle sleeve protrusion rib 12b, so as to prevent the liquid medicine from leaking out. Efficacy: a coupling rod 22d is connected to the front end of the needle stem part 22, and contains at least one pair of lugs 22e, and when the needle device 2 is mounted on the outside, it engages the female thread 21b in the hollow needle coupling sheath 21a; a buckle head 23 is located at the rear end of the needle, and there is a liquid discharge hole 24 in it, which communicates with the middle hole 20 of the needle, and injects the medicinal liquid into the human body.

When the hollow needle 21 is installed, when the coupling sheath 21a is rotated so that its female thread 21b is screwed into the lug 22e on the coupling rod 22d, the protrusion rib 22b of the needle stem is snapped into the needle sleeve protrusion inside the needle sleeve. Rib 12b, so the needle shaft 22 will not be linked and rotated by the hollow needle coupling sheath 21a, that is, the needle shaft 22 will not rotate, and the hollow needle can be smoothly screwed on the coupling rod 22d of the needle shaft.

The shallow dimple formed in the shoulder of the syringe in the prior art has been "exempted", so the liquid medicine can be completely injected into the human body through the middle hole 20 of the needle without causing the liquid medicine to stay and remain. In the syringe, so the present invention is better than the prior art.

The action principle of the present invention is briefly described as follows:

When the injection is completed, as shown in Figure 3, the deflected socket 32 in the piston 31 of the piston device 3 buckles the buckle head 23 of the needle, and is buckled into the socket 32 through the guide port 33; At 31 o'clock, the needle 2 is coupled and retracted into the interior of the syringe 10, as shown in Figure 4 in an oblique shape (deviating from the axis X), and when it is pushed forward, the needle 2 is bent and no longer protrudes. To achieve the purpose of safety.

The front end of the piston rod 35 of the piston device 3 is connected with a disk 35a, and then connected with a buckle end 34 to buckle the piston 31, and a disk-shaped ratchet hook 35b is arranged side by side behind the disk 35a, or on the disk. 35a rear is provided with many ratchet hooks 35b along the circumference ring of disc 35a, as shown in Fig. Slide button, through the flange ring 15 of the rear edge of the syringe, but when the piston rod 35 is pulled back, as shown in Figure 5, each ratchet hook portion 35b is blocked by the flange ring 15 and is not pulled out, so After the injection is completed, ensure that the plunger 31 is coupled with the injected needle 2, and will not be pulled out from the rear of the syringe, so that the needle cannot be stretched forward or retreated, and the safety of the safety syringe of the present invention is further ensured.

Regarding the structure of the ratchet hook portion 35b, in addition to the above, there are also other various structures and changes, and any appropriate modifications or changes made under the spirit and scope of the present invention all fall within the protection scope of the present invention.

Claims (5)

1. An improved exterior-mounted safety syringe, which includes a needle cover at the front end of the syringe device; the needle is installed on the syringe device, and the needle includes a hollow needle, a needle stem and a button head The needle stem is buckled in the needle sleeve, and the hollow needle is mounted and screwed on the needle stem; the piston device is slid in the barrel device, and a deflection socket is recessed on the piston to buckle the needle. The buckle head of the tool is characterized in that: the hole wall of the needle cover hole of the needle cover part is provided with a plurality of needle cover ribs; On the outer periphery of the needle cover, engage with the rib of the needle cover in the hole of the needle cover. 2. The improved exterior-mounted safety syringe according to claim 1, characterized in that: the needle stem is provided with a tightening ring which is arranged on the needle stem and stops at the rib of the needle sleeve protruding rib end. 3. The improved exterior-mounted safety syringe according to claim 1, characterized in that: the needle stem is provided with a flange plate connected to the rear end of the needle stem, and fastened to a part of the needle cover. in the hollow. 4. The improved exterior-mounted safety syringe according to claim 1, characterized in that: the front end of the piston rod of the piston device is connected with a disc whose front edge is arc-shaped, and is arranged along the circumference of the disc. There is at least one ratchet hook part, and a flange ring is arranged in the needle cylinder at the rear edge of the syringe device. 5. The improved exterior-mounted safety syringe according to claim 1, wherein the ratchet hook is a disk-shaped ratchet hook.