Injection pen with dial back and last dose control

Patent metadata

Field	Value
Publication number	US-12036396-B2
Application number	US-202117194108-A
Country	US
Kind code	B2
Filing date	Mar 5, 2021
Priority date	Dec 1, 2009
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A medication injection pen comprises a dose set knob rotatable with respect to a housing to set a desired injection dose. The dose set knob comprises at least one internal thread. A leadscrew includes a thread element for advancing in a first direction via a corresponding thread engagement. A driver is rotationally fixed to the leadscrew and is rotatable in a first direction to rotate and advance the leadscrew in the first direction. The setback member is rotationally fixed to the driver. The dose stop member is rotationally coupled to the setback member and is axially movable relative to the dose set knob when the dose set knob is rotated relative to the setback member. Axial movement of the dose stop member limits the user from setting a dose that is greater than an injectable volume of medication remaining in a cartridge.

First claim

What is claimed is:

1. A medication injection pen comprising:
a housing;
a dose set knob comprising at least one internal thread and being rotatable with respect to said housing during dose setting to set a desired injection dose;
a leadscrew provided with a thread element and advanceable in a first direction, said first direction being that which expels a medication from a cartridge;
a driver selectively rotatable with said dose set knob to rotate said leadscrew and advance said leadscrew in said first direction during dose injection;
a setback member rotationally fixed to said driver for preventing relative rotation therebetween; and
a dose stop member movably engaged with said dose set knob,
wherein
during said dose setting, said dose set knob is free to rotate with respect to said setback member, and said dose stop member is movable relative to said dose set knob when said dose set knob is rotated relative to said setback member
during said dose injection, said dose set knob is rotationally fixed with respect to said setback member and said dose stop member is not movable relative to said dose set knob, and
movement of said dose stop member with respect to said dose set knob limits setting of the desired injection dose that is greater than an injectable volume of medication remaining in the cartridge.

2. The medication injection pen according to claim 1 , wherein said dose stop member is rotationally movable with respect to said dose set knob when said dose set knob is rotated relative to said setback member, and said dose stop member is rotationally coupled to the setback member.

3. The medication injection pen according to claim 2 , wherein said dose stop member comprises a partial nut situated on said setback member between a pair of longitudinally extending ribs provided on said setback member.

4. The medication injection pen according to claim 2 , wherein said dose stop member is rotationally coupled to the setback member via engagement between corresponding ridges provided on an internal surface of said dose stop member and an external surface of said setback member.

5. The medication injection pen according to claim 4 , wherein said dose stop member comprises a ring link structure situated on said setback member.

6. The medication injection pen according to claim 1 , wherein the axial movement of said dose stop member is limited when a first edge of the dose stop member abuts a fixed stop on said dose set knob or on said setback member.

7. The medication injection pen according to claim 1 , wherein said dose stop member is rotationally coupled to said dose set knob, and said dose stop member is rotationally movable with respect to said setback member when said dose set knob is rotated relative to said setback member.

8. The medication injection pen according to claim 7 , wherein said dose stop member comprises a partial nut including internal threads engaging an external thread of said setback member.

9. The medication injection pen according to claim 7 , wherein said does set knob comprises two longitudinally extending ribs engaging corresponding edges of said dose stop element to rotationally couple said dose stop element to said dose set knob.

10. The medication injection pen according to claim 1 , further comprising:
a click element positioned between said dose set knob and said setback member, said click element comprising a first arm member engaging an internal surface of said dose set knob, and a second arm member engaging an external surface of said setback member, wherein one of the said first and second arms produces an audible signal when said dose set knob is rotated with respect to said housing.

11. The medication injection pen according to claim 10 , wherein
said internal surface of said dose set knob and said external surface of said setback member, each comprise a plurality of teeth, and
one of said first and second arms slides over ridges of said plurality of teeth of said setback member or ridges of said plurality of teeth of said dose set knob to produce the audible signal at each ridge.

12. The medication injection pen according to claim 11 , wherein said plurality of teeth of said dose set knob are configured to allow relative rotation between said dose set knob and said click element in a second rotational direction, and said plurality of teeth of said setback member are configured to allow relative rotation between said setback member and said click element in an opposite direction to the second rotational direction.

13. The medication injection pen according to claim 12 , wherein when said dose set knob rotates relative to said click element in said second rotational direction, said first arm produces the audible signal, and when said setback member rotates relative to said click element in said opposite direction to said second rotational direction, said second arm produces the audible signal.

14. The medication injection pen according to claim 1 , wherein said housing further comprises a flexible protrusion provided on a surface within said housing, and said dose set knob further comprises a flexible tab element which engages said protrusion to produce an audible signal upon completion of injection of a set dose.

15. The medication injection pen according to claim 14 , wherein when said dose set knob rotates relative to said housing to set the desired injection dose, said flexible tab element passes between a first edge of said protrusion and a sidewall of the housing, causing said protrusion to flex away from said sidewall.

16. The medication injection pen according to claim 15 , wherein said dose set knob rotates in an opposite direction to inject the desired injection dose, and in this direction, said flexible tab element engages a second edge of said protrusion causing said flexible tab element to flex radially inward, wherein once said flexible tab element passes an end of said protrusion, said flexible tab element returns to an initial position while providing said audible signal.

17. The medication injection pen according to claim 14 , wherein
the housing includes a channel having internal threads that threadedly engage the thread element of said leadscrew;
said channel includes a wall disposed on a top surface of said channel; and
said flexible protrusion is disposed on said wall of said channel.

Assignees

• Becton Dickinson Co

Inventors

• Cronenberg Richard E
• Quinn Michael
• Wu Haiming

Classifications

• A61M5/31595

  Pre-defined multi-dose administration by repeated overcoming of means blocking the free advancing movement of piston rod, e.g. by tearing or de-blocking · CPC title

• A61M5/31563

  interacting with a displaceable stop member · CPC title

• A61M5/3156

  using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals · CPC title

• A61M5/31535

  Means improving security or handling thereof, e.g. blocking means, means preventing insufficient dosing, means allowing correction of overset dose · CPC title

• A61M2205/581

  by audible feedback · CPC title