Pen needle assembly for preventing under-torquing and over-torquing of pen needle
View Patent ↗A pen needle hub and cover for a pen needle assembly that provides tactile and/or audible indicia of proper attachment between the hub of the pen needle and the pen is provided. Such indicia substantially prevent under- and over-torquing of the pen needle. The tactile indicia may include a user sensing a wave of a torque of peak value followed by a torque of lesser value.
1. A hub assembly for an injection apparatus, comprising:
a cover;
a hub disposed in said cover and having first and second ends and outer and inner surfaces, an opening being formed at said first end and threads being formed on said inner surface proximal said second end to facilitate connecting said hub assembly to a cartridge of said injection apparatus; and
a ring disposed inside said hub, said ring having a central opening to receive a cannula, an outer edge with at least one flexible tab engaging said threads, said ring being in a first position spaced from said second end, said ring having a flat configuration with a planar first side configured for contacting an inner face of said needle hub when said cartridge is coupled to said hub, and a planar outer face configured for contacting the cartridge of the injection apparatus when coupling the hub assembly to the cartridge, and where said ring has an outer annular surface extending between said first side and second side, and where said at least one tab extends outwardly from said outer annular surface;
wherein rotation of said cover and hub with respect to the cartridge causes said ring to move with respect to said threads toward said first end to a second position where said at least one flexible tab slides over said threads in a linear direction toward said first end of said hub to create audible indicia with said threads to indicated said hub is seated on said cartridge.
2. The hub assembly for an injection apparatus according to claim 1 , wherein said at least one flexible tab of said ring comprises a first tab and a second tab extending from opposite sides of said ring and engage said threads, and where said first tab and second tab create said audible indicia with said threads.
3. The hub assembly for an injection apparatus according to claim 2 , wherein said first tab and said second tab slide over said threads to create the audible indicia.
4. The hub assembly of claim 1 , wherein said hub has an inner axial surface facing said opening and a post extending from said inner axial surface in a direction toward said opening for supporting a cannula, and wherein said central opening in said ring has an inner dimension to receive said post when said ring seats against said inner axial surface.
5. The needle hub of claim 1 , wherein
said at least one tab comprises two flexible tabs extending outwardly from said outer annular surface and engaging said threads on said hub.