Details for Patent: 8,070,727

Title:	Drive mechanisms suitable for use in drug delivery devices
Abstract:	The present disclosure is directed to a dose setting mechanism that may be used with a drug delivery device. The dose setting mechanism may include an inner body having a helical thread along an outer cylindrical surface of the inner body, and a drive sleeve for driving a piston rod in an axial direction, the drive sleeve positioned within at least a portion of the inner body. The dose setting mechanism may further include a dose dial sleeve rotatably engaged with the helical thread of the inner body and a dial grip connected to the dose dial sleeve and releasably connected to the drive sleeve. Further when a dose is set, the dial grip is rotated so that both the dose dial sleeve and the drive sleeve rotate with respect to the inner body.
Inventor(s):	Veasey; Robert Frederick (Leamington Spa, GB), Langley; Christopher Nigel (Leamington Spa, GB), Wimpenny; Steven (Leamington Spa, GB)
Assignee:	DCA Design International Ltd. (GB)
Filing Date:	May 15, 2009
Application Number:	12/453,626
Claims:	1. A dose setting mechanism that may be used with a drug delivery device, comprising: an inner body having a helical thread along an outer cylindrical surface of said inner body; a drive sleeve for driving a piston rod in an axial direction, said drive sleeve positioned within at least a portion of said inner body; a dose dial sleeve rotatably engaged with said helical thread of said inner body; and a dial grip connected to said dose dial sleeve and releasably connected to said drive sleeve; wherein when a dose is set, said dial grip is rotated so that both said dose dial sleeve and said drive sleeve rotate with respect to said inner body, and wherein when said dose is injected, said dial grip is released from said drive sleeve and said drive sleeve is driven linearly to move said piston rod in an axial direction. 2. The mechanism of claim 1 wherein when said dose is injected, said dial grip remains connected to said dose dial sleeve and both said dial grip and said dose dial sleeve rotate back to an initial position. 3. The mechanism of claim 1 wherein said dial grip comprises first dog teeth, and said drive sleeve being operatively coupled with second dog teeth, such that connecting and disconnecting said first dog teeth of said dial grip and said second dog teeth operatively coupled with said drive sleeve provides said releasable connection between said dial grip and said drive sleeve. 4. The mechanism of claim 3 wherein said dial grip comprises a radial grip directed inward flange having said first dog teeth extending in a direction of a distal end of said drive mechanism. 5. The mechanism of claim 1 further comprising a main housing, said main housing surrounding at least a portion of said dose dial sleeve. 6. The mechanism of claim 5 wherein said dose dial sleeve is disposed between said main housing and said inner body. 7. The mechanism of claim 5 wherein said main housing comprises a window and said dose dial sleeve comprises a visual indication provided along an outer surface of said dose dial sleeve, such that said visual indication is viewable through said window of said main housing. 8. The mechanism of claim 5 wherein said main housing comprises a window and said dose dial sleeve comprises a visual indication provided along an outer surface of said dose dial sleeve, such that said visual indication is viewable through said window of said main housing when said dose is being set. 9. The mechanism of claim 1 wherein said drive sleeve is disposed between said inner body and said piston rod. 10. The mechanism of claim 1 wherein said dose setting mechanism is coupled to a cartridge. 11. The mechanism of claim 10 wherein said dose setting mechanism is permanently coupled to said cartridge. 12. The mechanism of claim 1 wherein said dial grip is rotated towards a user to set a dose. 13. A drug delivery device, comprising: a main housing; an inner body having an external helical thread; a dose dial sleeve engaged with said external groove of said inner body and positioned between said main housing and said inner body; a driving member positioned within said inner body; and a dial grip operatively coupled to both said dose dial sleeve and said driving member, said dial grip allows said dose dial sleeve and said driving member to rotate together during a dose setting operation of said drug delivery device, and wherein said dial grip prevents said drive member and said dose dial sleeve from rotating together during an injection of said dose. 14. The device of claim 13 wherein when said dose dial sleeve and said driving member rotate together during said dose setting operation, said dose dial sleeve and said driving member rotate at a same rate. 15. The device of claim 13 wherein said helical thread of said inner body comprises a female helical thread. 16. The device of claim 13 wherein said dose dial sleeve comprises a male groove engaged with said external groove of said inner body. 17. The device of claim 16 wherein said male groove of said dose dial sleeve comprises a male groove of less than 360 degrees. 18. The device of claim 13 wherein said drug delivery device comprises a resettable pen type drug delivery device. 19. The device of claim 13 wherein said drug delivery device comprises a non-resettable pen type drug delivery device.