The drive mechanism comprises a lead screw and a lead screw nut, which are aligned with an axis. The lead screw has screw threads having the same pitch and being intertwined.

A method of treatment may include providing a syringe having medicinal fluid therein for administering to a patient and coupling an attachment portion of an extrusion accessory having a handle and a pawl to a flange portion of the syringe. The pawl may have first and second ends, and be hingedly and rotatably coupled relative to the handle at a first position at the first end and at a second position between the first and second ends. The method may further include applying a force to translate the handle in a direction substantially perpendicular relative to a longitudinal axis of the syringe to cause axial movement of the second end of the pawl. The second end of the pawl may be engaged with a plunger of the syringe and axial movement of the second end of the pawl may drive the plunger forward to extrude the medicinal fluid from the syringe.

An assembly for a drug delivery device, comprising a housing having a proximal end and a distal end, a piston rod and an indicator. The piston rod is adapted to be displaced distally with respect to the housing away from a proximal start position and towards a distal end position for delivering a drug. The indicator is adapted for indicating at least two different operation conditions of the assembly, the indicator being moveable with respect to the housing from a first indication position for a first condition of the assembly into a second indication position for a second condition of the assembly. The piston rod and the indicator are configured to mechanically interact for converting movement of the piston rod into movement of the indicator. A first detent is provided which is configured to releasably secure the indicator in the first indication position such that movement into the second indication position is allowed. A second detent is provided which is configured to secure the indicator in the second indication position such that movement into the first indication position is prevented.

The present invention concerns a mechanism for a drug delivery device, having a longitudinal axis and comprising a first member comprising a first contact surface and a second member comprising a second contact surface, wherein the first member is configured to be assembled to the second member, wherein the first member and the second member are configured such that the first contact surface abuts the second contact surface when the first member is assembled to the second member, wherein the first contact surface is arranged such that a force applied to the mechanism in a direction parallel to the longitudinal axis is split up into a first component in a direction perpendicular to a surface normal of the first contact surface and a second component parallel to the surface normal, wherein the first member and the second member are configured such that the first member is detached from the second member by the force applied to the mechanism in a direction parallel to the longitudinal axis if the absolute value of the force is stronger than a first predetermined value, and wherein the first predetermined value is defined as the absolute value of the force which has a first component strong enough to move the first contact surface out of abutment with the second member.

An assembly for a drug delivery device includes an actuator configured to perform a setting movement in order to set a dose of medication and to perform a dispense movement in order to dispense a dose of medication. The assembly further includes a stop mechanism which is configured to allow a setting movement of the actuator after a maximum amount of medication has been delivered and to inhibit a dispense movement of the actuator after a setting movement when a maximum amount of a medication has been delivered.

Described herein are syringe extrusion accessories comprising: a handle operatively coupled to an attachment portion configured to attach to a syringe; and at least one pawl operatively coupled to the handle and configured to engage with a plunger of the syringe, wherein the syringe extrusion accessory is configured to transfer a substantially perpendicular force applied to the handle to an axial force to push the plunger and extrude a product from the syringe.

A dispensing mechanism for administering a dosage of a medicament includes dosage setting means (7) for setting the dosage of a medicament to be administered; expelling means (15) for expelling a medicament from a medicament container; and coupling means (21) operatively coupled with the dosage setting means (7) and the expelling means (15), wherein the coupling means (21) is arranged to convert displacement of the dosage setting means (7) into a displacement of the expelling means (15) in a first direction, wherein the expelling means (15) includes a ratchet means (18a, 18b), and wherein the mechanism includes a first and a second independently moveable resisting pawl (14a, 14b) means facing a common side of the ratchet means (18), the first and the second resisting pawl means (14a, 14b) being configured to engage with the ratchet means (18a, 18b) and resist displacement of the expelling means (15) in a second direction opposite to said first direction.

Medication delivery devices, sensing systems, and methods are disclosed for determining the relative axial and rotational movements of its members to determine the amount of a dose set and/or delivered by the medication delivery device. A sensing system comprises a barrel sensor system (100), a drive sleeve sensor system (130), and/or an axial sensor system (140). The barrel sensor system (100) is for detecting the absolute relative angular position of the barrel relative to the housing during dose setting. The drive sleeve sensor system (130) is for detecting the absolute relative angular position of the drive sleeve relative to the housing during dose delivery. The axial sensor system (140) is for detecting the relative axial positions of the dose dial relative to the housing during dose setting and delivery. A controller receives outputs from the sensor systems corresponding to the absolute relative positions to determine the actual amounts of dose set and delivered.

A medication delivery device is disclosed including a rack-and-pinion plunger drive system. The drive system includes an output drive having a pawled end movably coupled with the ratchet teeth of the plunger, and a pinion drive coupled between the housing, the output drive and an actuator. Actuator is longitudinally movable between dose set and delivery positions. Movement of the actuator causes rotation of the pinion drive along the rack to translate the output drive member with the pawled end that is engaged with the plunger ratchet teeth to distally advance the plunger. The device may include one or more of an end of dose mechanism to limit travel of the actuator, a load brake system to stop travel of the plunger under high input forces, a dose detection system, and a dose selector to vary the amount of dose set.

The present invention concerns a drive mechanism (3) for a drug delivery device (1), which comprises a piston rod (40) comprising a first piston rod member (7) and a second piston rod member (8). The drive mechanism (3) further comprises an adjustment member (9). The drive mechanism (3) has a first state in which the first and the second piston rod member (7, 8) are moveable with respect to each other by operating the adjustment member (9), thereby adjusting the length of the piston rod (40), and wherein the adjustment member (9) is arranged at least partially inside the second piston rod member (8). Moreover, the present invention concerns a method for assembling the drug delivery device (1).