Auto injector with cartridge locking system
A system comprising an auto injector and a cartridge assembly comprising at least one cartridge retention member. The auto injector includes a housing; a cartridge receiver with a cartridge receiver compartment configured to receive a cartridge or a cartridge assembly including at least one cartridge retention member, when inserted through a cartridge receiver opening along a longitudinal axis (L) in a receiving direction; an elongated ejector including an ejector support face for supporting the cartridge or cartridge assembly, and a longitudinal ejector slot extending towards the ejector support face from an ejector rest portion; wherein the elongated ejector is suspended to move along the longitudinal direction and is spring-loaded in the direction opposite of the receiving direction; and an ejector lock supported for turning at least a fraction of a revolution and maintained in a longitudinal position relative to the housing.
1 . A system comprising an auto injector and a cartridge assembly comprising at least one cartridge retention member, wherein the auto injector comprises:
a housing;
a cartridge receiver with a cartridge receiver compartment configured to receive the cartridge assembly comprising the at least one cartridge retention member, when inserted through a cartridge receiver opening along a longitudinal axis in a receiving direction; wherein the cartridge receiver has a passage through which the at least one cartridge retention member travels at least in the receiving direction, and a member preventing movement beyond a retention position in a direction opposite of the receiving direction;
an elongated ejector that is configured with: an ejector support face for supporting the cartridge assembly, a longitudinal ejector slot extending towards the ejector support face from an ejector rest portion; wherein the elongated ejector is suspended to move along the longitudinal direction and is spring-loaded in the direction opposite of the receiving direction; and
an ejector lock rotatable relative to an end of the elongated ejector opposite the ejector support face, the ejector lock supported for turning at least a fraction of a revolution and maintained in a longitudinal position relative to the housing; wherein the ejector lock has an ejector lock support portion that is configured to align with and slide along the longitudinal ejector slot at a first angle and to be brought to align with the ejector rest portion at a second angle.
2 . The system according to claim 1 , wherein the cartridge is a dual chamber cartridge.
3 . The system according to claim 1 , wherein the ejector comprises an ejector rod with the ejector support face; wherein the ejector rod has an ejector rod bore to form a longitudinal passage, and wherein the ejector support face is arranged at one end of the ejector rod and has a disc shape or an annular shape.
4 . The system according to claim 1 , wherein an ejector rod comprises an ejector collar arranged about the ejector support face.
5 . The system according to claim 1 , wherein the ejector comprises an ejector rod configured with one or more ejector cut-outs to form one or more ejector cogs between the ejector cut-outs; and wherein the ejector lock is configured with one or more ejector lock cogs between one or more ejector lock cut-outs, respectively.
6 . The system according to claim 5 , wherein one or more of the cut-outs and the cogs have a substantially rectangular shape.
7 . The system according to claim 5 , wherein the one or more cut- outs and the one or more cogs comprise a portion that is inclined relative to the longitudinal axis and relative to an axis orthogonal to the longitudinal axis.
8 . The system according to claim 5 , wherein the ejector cogs and the lock cogs comprise an end portion that is inclined relative to the longitudinal axis at an angle of less than 40 degrees, or less than 30 degrees, or less than 20 degrees relative to the orthogonal of the longitudinal axis.
9 . The system according to claim 5 , wherein the ejector comprises the ejector rod configured with a substantially cylindrical portion with one or more chamfers about the longitudinal axis to form a rotational asymmetric end portion; and wherein the ejector lock is configured with one or more complementary chamfer cuts to form a complementary rotational asymmetric end portion.
10 . The system according to claim 1 , comprising a plunger rod;
wherein the ejector comprises an ejector rod which is spring-loaded by a spring ejector member;
wherein the plunger rod and a bore are configured for longitudinal relative movement.
11 . The system according to claim 10 , wherein the plunger rod comprises an inner plunger rod and an outer plunger rod; wherein the inner plunger rod and the outer plunger rod are coupled by a thread;
wherein the inner plunger rod is retained in a bearing allowing rotation of the inner plunger rod while preventing a longitudinal movement; and wherein the outer plunger rod is retained in an angular position relative to the housing.
12 . The system according to claim 11 , comprising an angle retaining slot and an angle retaining guide configured to engage with each other and arranged on or in the cartridge receiver or a member rigidly coupled to the cartridge receiver and at the ejector rod.
13 . The system according to claim 1 , wherein the ejector lock comprises an ejector lock guide pin configured to engage with a plunger rod track provided in the plunger rod, such that longitudinal movement of the plunger rod, at least over a predefined range, inflicts a turning of the ejector lock about the longitudinal axis.
14 . The system according to claim 13 , wherein movement of the plunger rod in the receiving direction, at least over a range of longitudinal positions, inflicts a turning of the ejector lock to a first angular position.
15 . The system according to claim 13 , wherein the ejector lock is configured with an ejector lock bore to accept at least an end portion of an outer plunger rod and an ejector lock guide pin that extends inwardly from a wall of the ejector lock bore;
wherein the outer plunger rod is configured with a plunger rod track that engages with the ejector lock guide pin and extends from a plunger rod distal rim towards the cartridge assembly opening;
wherein the plunger rod track has at least one track portion that leads the ejector lock guide pin from the first angle to the second angle that are angularly spaced apart to turn the ejector lock from a first angular position to a second angular position.
16 . The system according to claim 15 , wherein the plunger rod track is configured as a recess that extends from the plunger rod distal rim of the outer plunger rod.
17 . The system according to claim 1 , wherein the ejector lock is coupled to a resilient member that biases the ejector lock towards a second angular position.
18 . The system according to claim 1 comprising a drive module with a motor and one or more of transmission and gearing to couple the motor to an inner plunger rod.