CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is claims the benefit of priority of Chinese Patent Application number 201810559378.3 filed Jun. 1, 2018, which is incorporated by reference in its entirety.

TECHNICAL FIELD

The embodiment of the present disclosure relates to the field of medical instruments, more particularly, to a disposable injection needle.

BACKGROUND

Conventional injection needle which is common in the market and cooperates with an insulin injection pen, comprises a big sleeve, a small sleeve, a needle mount, a tube needle and dialyzing paper. The needle tip of the tube needle will be exposed all the time once the big sleeve and the small sleeve are removed, which increases the infection probability for the patients because of secondary use, and the used needle is apt to accidentally injure other people and thus causes cross-infection.

In addition, the big sleeve tends to slide outside the needle mount when the injection needle is being engaged with the injection pen, leading to poor working conditions, for instance unstable assembling.

SUMMARY

The present disclosure is proposed to alleviate or solve at least one aspect of the above problems.

According to one aspect of the embodiments in the present disclosure, the present disclosure provides a disposable injection needle, which comprises:

a needle mount provided with a tube needle that extends axially therethrough;

a first sleeve, one end of which is suitable for connecting to one end of the needle mount to form receiving space between the first sleeve and the needle mount, and the other end of the first sleeve is provided with a first opening;

a second sleeve, one end of which is located inside the receiving space, and the other end of which having a second opening, extends out from the first opening, wherein part of the second sleeve is provided, in an axially slideable manner, inside the receiving space, and the tube needle is adapted to protrude through the second opening;

an elastic element adapted to provide elastic force for the second sleeve to move axially toward outside the receiving space, and the second sleeve is adapted to retract inward the receiving space based on an external force overcoming the elastic force, thus to expose the tube needle,

wherein:

the second sleeve is provided with a sleeve guiding portion, and the needle mount or first sleeve is provided with a guiding engagement portion, the sleeve guiding portion engages with the guiding engagement portion to guide circumferential rotation of the second sleeve based on axial movement of the second sleeve toward inside the second sleeve;

the first sleeve is provided with a blocking member and the second sleeve is provided with a fastener, wherein the blocking member and the fastener are arranged to allow the fastener to pass through the blocking member in the axial direction toward the second opening, and to prevent the fastener from passing through the blocking member in the axial direction away from the second opening to prevent the tube needle from being exposed via the second opening.

Alternatively, the inner wall of the first sleeve is provided with a limit guiding slot in which the blocking member is provided; and the fastener is adapted to enter the limit guiding slot due to the rotation of the second sleeve in circumferential direction. Further, the inner wall of the first sleeve is provided with a first guiding rib, a second guiding rib and a third guiding rib which extend in the axial direction and are spaced apart from one another and parallel to one another, wherein a first guiding groove is formed between the first guiding rib and the second one, and a second guiding groove, constituting the limiting guiding slot, is formed between the second guiding rib and the third one; due to the circumferential rotation, the fastener is adapted to move circumferentially from the first guiding groove to the second guiding groove. Furthermore, corresponding to the circumferential movement, one side of the second guiding rib facing the first guiding groove is provided with a face that facilitates moving of the fastener across the second guiding rib; and/or one side of the fastener facing the second guiding rib is provided with a face that facilitates moving of the fastener across the second guiding rib. Further, the cross section of the portion of the second guiding rib, from the blocking member to the first opening is a rectangle, and the cross section of the portion of the second guiding rib, from the blocking member to the end of the first sleeve, is a right trapezoid, with the hypotenuse of the right trapezoid facing the first guiding groove.

Alternatively, the needle mount is provided with a guiding engagement portion; the needle mount is provided with a needle mount guiding portion, the end of which is provided with a needle mount guiding slope which constitutes the guiding engagement portion; the second sleeve includes a sleeve guiding arm which is adapted to move axially and circumferentially inside the needle mount guiding portion, and the end of the sleeve guiding arm is provided with an engaging slope which engages with the needle mount guiding slope and which constitutes the sleeve guiding portion; and the distance or the width of the needle mount guiding portion is greater than that of the sleeve guiding arm in the circumferential direction, so as to allow the second sleeve to complete the circumferential rotation. further, the end of the needle mount guiding portion is additionally provided with a pressing blocking face connected to the needle mount guiding slope; the end of the sleeve guiding arm is provided with an engagement blocking face which is connected to the engaging slope, and which abuts against the pressing blocking face to prevent the second sleeve from moving axially further after the second sleeve completes its circumferential rotation.

Alternatively, the second sleeve is provided with a sleeve limit arm, whose end is provided with the fastener. Further, the side of the fastener facing the second opening is set as a compliant face, and the other side of the fastener facing the compliant face in the axial direction is set as a blocking face; besides, the side of blocking member facing the first opening is set as a blocking face engaging with the blocking face of the fastener; or, the side of the blocking member facing the first opening is set as a blocking face engaging with the blocking face of the fastener, and the other side of the blocking member opposite to the its blocking face in the axial direction is provided with a compliant face cooperating with the compliant face of the fastener.

Alternatively, the first sleeve is provided with a guiding groove and limit guiding slot; the first sleeve is provided with the guiding engagement portion, which is an inclined guiding slot or a cambered guiding slot connecting the end of guiding groove and that of the limit guiding slot; the second sleeve includes a sleeve guiding arm, wherein the fastener is provided at the end of the sleeve guiding arm, and the blocking member is provided inside the limit guiding slot; and the fastener is adapted to enter the limit guiding slot via the inclined guiding slot or the cambered guiding slot due to the circumferential rotation.

Alternatively, the first end of the needle mount is provided with an elastic element limiting column, which extends axially from the first end of the needle mount, and through which the tube needle extends axially; the other end of the second sleeve has a second blocking face, which is perpendicular to the axis and defines the second opening; the elastic element includes a spring, one end of which is provided to the elastic element limiting column and the other end of which presses against the second blocking face.

Alternatively, one end of the elastic element is fixed to the first sleeve and the other end of the elastic element is fixed to the needle mount, and the elastic element provides the elastic pulling force causing the needle mount to move axially toward outside the receiving space.

Alternatively, one end of second sleeve is located inside the receiving space and the other end of the second sleeve is provided with the second opening and extends out from the first opening, and one part of the second sleeve is provided in an axially slideable manner inside the receiving space. Further, the second sleeve has a small-diameter section and a large-diameter section connected to each other axially, a step surface is formed at the junction there between, wherein, the small-diameter section is suitable for axially extending out of the first sleeve from the first opening, and the distal end of the small-diameter section has the second opening and the second blocking face which is perpendicular to the axis and defines the second opening, the step surface is adapted to abut against the first blocking face, while the large-diameter section is provided in an axially slideable manner inside the receiving space.

Alternatively, the first end of the needle mount is additionally provided with an engaging circumferential surface; and one end of the first sleeve is suitable for being sleeve-jointed to the engaging circumferential surface.

Alternatively, the disposable injection needle further includes a third sleeve, which sleeve-joints the needle mount, the first sleeve and the second sleeve from outside. Further, a first anti-rotational mechanism is provided at the junction between the first sleeve and the needle mount, and a second anti-rotational mechanism is provided at the junction between the third sleeve and the needle mount. Further, the disposable injection needle also includes dialyzing paper, which is provided to cover the opening of the third sleeve.

Alternatively, the other end of the needle mount is provided with a connecting device suitable to connect with the injection pen.

Alternatively, the second sleeve is provided with two guiding portions and two limit arms, wherein the two limit arms are arranged to be opposite to each other in the radial direction, and the two guiding portions are arranged to be opposite to each other in the radial direction.

In the embodiments of the present disclosure, with the internal structure design of the injection needle assembly, the needle tip of the tube needle will not be exposed to the outside after being used.

