Pen needle assembly for preventing under-torquing and over-torquing of pen needle

1. A hub assembly for an injection apparatus, comprising:

a cover having outer and inner surfaces;

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;

a plurality of radially extending protrusions formed on said outer surface of said hub;

at least one radially extending rib formed on said inner surface of said cover such that said at least one rib is disposed between adjacent protrusions when said hub is disposed in said cover;

each of said plurality of protrusions and said at least one rib having mating sloped surfaces to facilitate movement of said at least one rib over said plurality of protrusions;

a first tooth formed on each of said sloped surfaces of said plurality of protrusions; and

a second tooth formed on said sloped surface of said at least one rib, such that an audible indicia is generated when said second tooth of said at least one rib passes over said first tooth of said plurality of protrusions when said hub assembly is properly connected with the cartridge, thereby indicating to the user that said hub assembly and the cartridge are properly connected.

2. The hub assembly for an injection apparatus according to claim 1 , wherein

said plurality of protrusions comprise inwardly extending grooves.

3. The hub assembly for an injection apparatus according to claim 2 , wherein

a projection extends outwardly from said second end of said hub and received by said cover;

a second plurality of grooves are formed in an outer surface of said projection; and

a second plurality of protrusions are formed on an inner surface of said cover that engage said second plurality of grooves such that audible indicia is generated when said hub assembly and the cartridge are properly connected.

4. A hub assembly for an injection apparatus, comprising:

a cover having outer and inner surfaces;

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;

at least one protrusion formed on said outer surface of said hub proximal said first end;

at least one cut-out portion formed in said inner surface of said cover; and

a cantilever hook formed in each of said at least one cut-out portions of said cover, said cantilever hook having an arm and a projection such that when said hub is disposed in said cover said at least one protrusion engages said arm of said at least one cantilever hook such that an interference fit is formed between said hub and said cover;

wherein said at least one protrusion moves along said at least one cantilever hook when said hub assembly is being connected with the cartridge, and when said hub assembly is properly connected to the cartridge continued rotation of said cover with respect to the cartridge causes said at least one protrusion to slide over said projection of said cantilever arm into said cut-out portion thereby indicating to the user that said hub assembly and cartridge are properly connected;

wherein said projection has a first ramped surface and a second ramped surface, said first ramped surface being closer to said arm and being steeper than said second ramped surface; and

wherein at least one tab is disposed on an inner surface of said cover and adapted to engage said at least one protrusion when said hub assembly is being disengaged from the cartridge.

5. The hub assembly for an injection apparatus according to claim 4 , wherein

further rotation of said hub assembly is prevented when said at least one protrusion is disposed in said at least one cut-out portion.

6. A hub assembly for an injection apparatus, comprising:

a cover having outer and inner surfaces;

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;

a plurality of cavities extending inwardly into said inner surface of said cover; and

at least one projection formed on said outer surface of said hub;

wherein when said hub assembly is properly connected to the cartridge, continued rotation of said hub with respect to the cartridge causes said plurality of cavities to move over said at least one projection, thereby indicating to the user that said hub assembly and the cartridge are properly connected;

wherein said at least one projection is formed on a flexible arm to facilitate movement said at least one projection in and out of said plurality of cavities.

7. The hub assembly for an injection apparatus according to claim 6 , wherein

said plurality of cavities are evenly spaced around a circumference of said inner surface of said cover.

8. The hub assembly for an injection apparatus according to claim 6 , wherein

said at least one projection extends outwardly from said outer surface of said hub in a radial direction.

9. A hub assembly for an injection apparatus, comprising:

a cover having outer and inner surfaces;

a hub disposed in said cover and having a base and a side wall extending outwardly from said base, threads being formed on an inner surface of said side wall to facilitate connecting said hub assembly to a cartridge of said injection apparatus;

a projection formed on said hub; and

a membrane formed on said cover;

wherein when said hub assembly is properly connected to the cartridge, continued rotation of the cover with respect to the cartridge causes said projection to puncture said membrane, thereby creating audible indicia to the user that said hub assembly and the cartridge are properly connected.