| CPC A61M 5/3257 (2013.01) [A61M 2005/3254 (2013.01)] | 10 Claims |
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1. A rotational locking type safety insulin pen needle comprising:
a needle body with an injection section at a front end of the needle body and a connecting section at a rear end;
an intermediate shield of tube structure comprises with a through hole at a front end of the intermediate shield and connected or provided with a structure to connect an insulin pen at a rear end of the intermediate shield;
a front shield, and the front shield is used to protect the injection section of the needle body, and a main structure of the front shield is a tubular body;
a front spring, and the front spring is used to push the front shield to a protection position of the injection section of the needle body;
a rotating tube where a main structure of the rotating tube is a tubular body, and the rotating tube comprises an elastic arm at a front end of the rotating tube, and the elastic arm comprises a front protection stopper protruding outside of the tubular body, the front protection stopper is comprises a flange at a top of the front protection stopper and a front stopping face; and the tubular body of the rotating tube comprises a beveled rail on an outer edge, and the beveled rail comprises a section of bevel or spiral surface as a guiding surface relative to an axis of the rotating tube;
the front shield comprises a limit slot on an inner edge relative to the front protection stopper on the rotating tube along an axial direction of the tubular body of the front shield, and a stopping face at a rear end of the limit slot relative to the front stopping face of the front protection stopper;
the front shield comprises a bevel acting part on its inner edge relative to the beveled rail on the rotating tube;
in an assembled state before use:
the needle body is located in the intermediate shield, and is positioned and fixed relative to the intermediate shield;
the rotating tube is located in the intermediate shield, and is axially positioned and connected relative to the intermediate shield, and is rotationally connected circumferentially;
a rear part of the front shield extends into the intermediate shield and is sleeved outside the rotating tube, and a front part of the front shield extends out of the through hole at a front end of the intermediate shield, and the front shield and the intermediate shield are slidably connected in the axial direction, and the front shield comprises a front end limit;
the front protection stopper on the rotating tube and the limit slot on the inner edge of the front shield are misaligned in a circumferential direction;
the bevel acting part on the inner edge of the front shield is located on the beveled rail; and
the front spring is sleeved outside of the rotating tube and is located in the intermediate shield, and a rear end of the front spring is positioned relative to the intermediate shield and a front end of the front spring is against the front shield; and
in a use state, when the insulin pen needle is pushed, the front shield moves backward axially relative to the intermediate shield, and the bevel acting part on the inner edge of the front shield and the beveled rail on the outer edge of the rotating tube coordinate with each other to force the rotating tube to rotate in the circumferential direction relative to the front shield, and the front protection stopper on the rotating tube transversely slides to the limit slot from the inner edge of the front shield; when the insulin pen needle is pulled out, the front spring pushes the front shield forward, and when the front shield moves forward relative to the intermediate shield, the front protection stopper upsprings at the rear end of the limit slot, and at this time, the front stopping face of the front protection stopper is against the stopping face at the rear end of the limit slot, so that the front shield is axially positioned relative to the intermediate shield and enters a front-end protection state.
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