US 12,453,821 B2
Injector pen and dose adjustment mechanism thereof
Changyan Xiong, Jiangsu (CN); Huashun Li, Jiangsu (CN); and Sixian He, Jiangsu (CN)
Assigned to SUZHOU HEALTHY TREE MEDICAL TECHNOLOGY CO., LTD, (CN)
Appl. No. 18/861,729
Filed by SUZHOU HEALTHY TREE MEDICAL TECHNOLOGY CO., LTD, Jiangsu (CN)
PCT Filed Apr. 1, 2024, PCT No. PCT/CN2024/085211
§ 371(c)(1), (2) Date Oct. 30, 2024,
PCT Pub. No. WO2025/152271, PCT Pub. Date Jul. 24, 2025.
Claims priority of application No. 202410058074.4 (CN), filed on Jan. 16, 2024.
Prior Publication US 2025/0288747 A1, Sep. 18, 2025
Int. Cl. A61M 5/315 (2006.01); A61M 5/20 (2006.01)
CPC A61M 5/31551 (2013.01) [A61M 5/20 (2013.01); A61M 5/31528 (2013.01); A61M 5/3158 (2013.01); A61M 2005/2026 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A dose adjustment mechanism of an injector pen, comprising:
a power rod;
a cylinder;
a ball;
a sleeve; and
a torsion spring;
wherein the cylinder is mounted outside the power rod, a spiral channel extending along an axis direction of the power rod is formed between an inner wall of the cylinder and an outer wall of the power rod, and the ball is rollable in the spiral channel;
the cylinder and an upper pen holder of the injector pen are relatively fixed in a circumferential direction; an upper end of the torsion spring is relatively fixed to the upper pen holder, and an lower end of the torsion spring is connected to the sleeve;
the power rod is rotatable relative to the cylinder under an action of external force; the sleeve is limitedly connected with the power rod in the circumferential direction, and the sleeve is configured for transmission cooperation with a transmission mechanism of the injector pen;
the sleeve comprises a rod insertion portion, the power rod comprises a socket portion extending along the axial direction, the rod insertion portion is inserted into the socket portion, an outer peripheral wall of the rod insertion portion has a flat portion in the circumferential direction, and an inner hole wall of the socket portion has a flat wall that cooperates with the flat portion;
the dose adjustment mechanism further comprises an axial limiting structure between the power rod and the sleeve, so as to limit a relative position of the power rod and the sleeve in the axial direction.