Compliant coupling assembly for cartridge coupling of a drug delivery device
An assembly for coupling a drug delivery device to a cartridge is disclosed. Optionally the assembly includes a coupling, for example a cannula, having one end extending toward the cartridge. The cartridge is optionally aligned by a guide. Optionally the cartridge has a limited freedom of movement. The coupling is optionally supported by a mount. In some embodiments, the mount is compliant enough that the end of the coupling that extends toward may move to said limited freedom of movement under a force less than a leak threshold of the connection between the coupler and the cartridge.
1. An assembly for coupling a drug delivery device to a cartridge sealed by a septum, the assembly comprising:
an axially extending cannula having a tip region configured to penetrate the septum, said tip region having a width; and
a frame including:
an axially extending guide sized and shaped to secure the cartridge to said frame; and
a mount pivotably positioned on said frame, the cannula being attached to said mount such that said tip region of said cannula protrudes through the septum of the cartridge when said cartridge is secured to said frame by said guide;
wherein a requisite degree of movement between the cannula and the septum at an interface therebetween to cause leakage at the interface defines a leak threshold force of the septum, and
wherein said mount permits transaxial movement of said tip region of said cannula by at least a distance equal to the width of the tip region in response to a force applied to the cannula at the interface between the cannula and the septum of less than the leak threshold force.
2. The assembly of claim 1 , wherein a force of less than a leak threshold force of said septum moves said tip region of said cannula transaxially at least a distance equal to a position deviation tolerance of said septum.
3. The assembly of claim 1 , wherein said distance is greater than a movement caused by a flexibility of said frame and said cannula under said leak threshold force.
4. The assembly of claim 1 , wherein said mount compensates for a movement of said cannula at a stress level less than a bending stress of said cannula.
5. The assembly of claim 1 , wherein said leak threshold force is 6 N.
6. The assembly of claim 1 , further comprising:
a base located on a side of said cannula opposite said tip region, said base inhibiting backwards movement of said tip region.
7. The assembly of claim 6 , wherein said base is positioned off axis of said cannula.
8. The assembly of claim 1 , wherein said mount is configured to bias movement of said cannula in a particular direction.
9. The assembly of claim 8 , wherein said particular direction is parallel to a face of a bevel of a tip of said cannula.
10. The assembly of claim 1 , wherein said cannula is bent at an angle ranging between 30 to 80 degrees.
11. The assembly of claim 1 , wherein a second end of said cannula is connected to a flexible fluid path.
12. The assembly of claim 1 , wherein the cartridge is coupleable to said cannula by a linear movement of the cartridge with respect to the guide.
13. The assembly of claim 1 , wherein said compliant mount is flexible.