Medicament delivery device with a locking mechanism

Patent metadata

Field	Value
Publication number	US-12496405-B2
Application number	US-202017798641-A
Country	US
Kind code	B2
Filing date	Dec 21, 2020
Priority date	Mar 17, 2020
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

A dose delivery mechanism and a medicament delivery device are presented having a housing holding a medicament container and a power unit, where the power unit has a plunger rod, a drive spring, operably arranged to act on the plunger rod and on the medicament container. A locking ring is operatively engaged with an actuator having a holding ledge that can releasably hold the plunger rod with the drive spring in a tensioned state, and with an actuator sleeve to form a lock that prevents axially movement of the actuator after dose delivery. The locking ring also cooperates with the actuator to generate an end-of-dose delivery signal. An activator is directly engaged with the actuator to provide a well-defined activation point.

First claim

I claim:

1 . A dose delivery mechanism comprising:
a plunger rod comprising a groove on an outside surface; an actuator having a holding ledge engaged with the groove such that the plunger rod is held in a first axial position, where disengagement of the holding ledge from the groove allows the plunger rod to move to a second axial position; an actuator sleeve biased proximally by a sleeve spring and movable in both a distal and proximal direction, where the actuator sleeve has a flexible finger; an activator movable in a proximal direction and directly engaged with the actuator such that axial movement of the activator moves the actuator proximally relative to the actuator sleeve; and a locking ring slidably engaged and rotationally fixed with an outside surface of the actuator and engaged with the sleeve spring, where the locking ring has a proximally extending first leg that abuts a flexible arm of the actuator when the plunger rod is in the second axial position.

2 . The dose delivery mechanism of claim 1 , wherein relative movement between the first leg and the flexible arm generates an end of medicament notification through a tactile or audible signal.

3 . The dose delivery mechanism of claim 1 , wherein the locking ring has a proximally extending second leg that abuts the flexible finger after the plunger rod has moved to the second axial position to form an axial lock that prevents axial movement of the actuator sleeve in a distal direction.

4 . The dose delivery mechanism of claim 3 , further comprising a medicament delivery guard axially fixed to the actuator sleeve.

5 . The dose delivery mechanism of claim 4 , where the medicament delivery guard is configured to have a first position, a second position and a third position relative to the activator.

6 . The dose delivery mechanism of claim 4 , wherein the flexible finger of the actuator sleeve comprises a radial inward directed protrusion that abuts a proximal facing end surface of the second leg when the plunger rod is in the second axial position such that the medicament delivery guard is prevented from axial movement in the distal direction relative to the actuator.

7 . The dose delivery mechanism of claim 4 further comprising a holding element releasably engaged with the groove when the plunger rod is in the first axial position and disengaged from the groove when the plunger rod is in the second axial position.

8 . The dose delivery mechanism of claim 7 further comprising a medicament container holder axially fixed to the holding element and slidably positioned inside the medicament delivery guard.

9 . The dose delivery mechanism of claim 4 , wherein axial movement of the medicament delivery guard in a distal direction causes the actuator sleeve to move distally to an activation state.

10 . The dose delivery mechanism of claim 9 , wherein axial movement of the activator in a proximal direction when the actuator sleeve is in the activation state causes the actuator to move relative to the actuator sleeve such that the holding ledge will disengage from the groove.

11 . The dose delivery mechanism of claim 1 , wherein an inside surface of the locking ring has a first set of splines that are slidably engaged with a second set of splines on the outside surface of the actuator that prevent relative rotation of the locking ring.

12 . The dose delivery mechanism claim 1 , wherein the plunger rod is hollow.

13 . The dose delivery mechanism of claim 12 , wherein a drive spring is located inside the plunger rod.

14 . The dose delivery mechanism of claim 13 further comprising a guide rod positioned inside of the drive spring, where the guide rod has a distal end portion configured to slidably engage a distal end of the actuator such that the guide rod is rotationally fixed relative to the actuator.

15 . The dose delivery mechanism of claim 14 , wherein the drive spring is biased between the distal end portion of the guide rod and a proximal interior wall of the plunger rod when the plunger rod is in the first axial position.

16 . The dose delivery mechanism of claim 1 , wherein the activator comprises a tongue that is biased radially outward relative to the plunger rod, and wherein the holding ledge is located at a proximal end of the tongue.

17 . The dose delivery mechanism of claim 1 , wherein the actuator sleeve is arranged slidable in relation to the actuator.

18 . The dose delivery mechanism of claim 1 , wherein a distal end surface of the locking ring is engaged with a distal end of the sleeve spring.

19 . The dose delivery mechanism of claim 1 , wherein the holding ledge is an annular inwardly directed ledge, and wherein the holding ledge is arranged in the groove prior to use of the dose delivery mechanism to deliver a medicament.

20 . A medicament delivery device comprising:
a housing, where the dose delivery mechanism of claim 1 is positioned within the housing; a medicament container operatively connected to the dose delivery mechanism; and a medicament delivery member connected to the medicament container.

Assignees

• Shl Medical Ag

Inventors

• Maxfield Brian

Classifications

• A61M2205/582

  by tactile feedback · CPC title

• A61M2205/581

  by audible feedback · CPC title

• A61M2205/273

  preventing reuse, e.g. of disposables · CPC title

• A61M2005/208

  Release is possible only when device is pushed against the skin, e.g. using a trigger which is blocked or inactive when the device is not pushed against the skin · CPC title

• A61M5/3158

  performed by axially moving actuator operated by user, e.g. an injection button · CPC title