A device includes a motor and a hollow drive shaft. The motor is configured to rotate the hollow drive shaft. A lead screw nut is operably connected to the hollow drive shaft. The lead screw nut is configured to rotate upon rotation of the hollow drive shaft. A lead screw is operably connected to the lead screw nut. The lead screw is configured to move within the lead screw nut and the lead screw is configured to pass through at least part of the hollow drive shaft.

An injection device includes a housing; a receptacle for injection fluid; a dosing piston to press out the injection fluid; a feed part connected to the dosing piston via a first threaded connection; a slide having a thread of a second threaded connection; and, a setting part having a thread of a third threaded connection and configured to set an amount of injection fluid to be dispensed. The setting part moves in the distal direction by virtue of the third threaded connection when the amount of injection fluid to be dispensed is being set. The setting part can move in the proximal direction when the injection fluid is pressed out. A latching unit defines a latching position of the setting part and acts between the setting part and housing. Each latching position has an unequivocal rotational position of the setting part in relation to the housing assigned thereto.

An injector apparatus includes a housing (10.sup.1, 10.sup.2) for a cartridge or syringe, a plunger (40) for cooperating in use with the cartridge or syringe to express successive doses, a dose setting arrangement (16, 20) to select a dose volume, and a drive mechanism (22, 24) releasable to advance the plunger in respective predetermined increments of magnitude to express the successive doses. The drive mechanism includes a drive spring (22) for imparting movement directly or indirectly to the plunger (40), and the dose setting arrangement includes a dose setting element (16) moveable in a dose setting routine to define a magnitude of an increment of movement of the plunger for a given dose. The drive mechanism further includes a clutch arrangement (56) operable during the dose setting routine to inhibit forward movement of the plunger and/or to isolate the dose setting element from the force of the drive spring.

Disclosed herein are delivery devices for delivering a volume of a drug product, placebo product, or other product including a fluid. The devices may include a barrel having a longitudinal axis, a proximal end region, and a distal end region. The proximal end region may include an opening, and the barrel may be configured to receive a drug therein. A plunger rod may be disposed at least partially inside the barrel and protruding from the opening. The plunger rod may include a rack having a plurality of teeth. The device may further include a pinion having a plurality of teeth configured to engage with the plurality of teeth of the rack, and rotation of the pinion against the rack may move at least a part of the plunger rod along the longitudinal axis of the barrel.

A dose setting mechanism comprising a first element and a second element; the first element being moveable with respect to the second element; the first element and the second element being coupled by a ratchet mechanism allowing motion of the first element with respect to the second element from a first position to a second position only in a first direction while preventing motion in a second direction that is opposite to the first direction; once passing the second position, the first element being moveable with respect to the second element in the first direction and in the second direction.

A drive mechanism for a drug delivery device having a rotationally fixed plunger rod driven by a lead screw. The lead screw engages a free lock which is coupled to a release knob. A dose setting dial cooperates with an inner cylinder using a clutch to establish the axial movement of the plunger rod during dose setting and dispensing.

A drive mechanism for a drug delivery device having a rotationally fixed plunger rod driven by a lead screw. The lead screw engages a free lock which is coupled to a release knob. A dose setting dial cooperates with an inner cylinder using a clutch to establish the axial movement of the plunger rod during dose setting and dispensing.

A medicament delivery device having a housing, arranged to accommodate 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 said medicament container, an actuator having holding elements that can releasably hold the plunger rod with said drive spring in a tensioned state, and an actuator sleeve operably connected to said actuator for releasably locking said holding elements in a holding state. The medicament delivery device also can have a medicament delivery member guard slidably movable in said housing that can act on said actuator sleeve for setting said holding elements with said actuator sleeve in a first activation state; an activator unit arranged to be manually operated and which is operably connected to said plunger rod for setting said holding elements with said actuator sleeve in a second activation state.

The present disclosure relates to a dose detection system for use with a medication delivery device in which a dose setting member rotates relative to an actuator during dose delivery. The dose detection system includes a module which is removably attached to the medication delivery device. The module includes a rotation sensor attached to the actuator during dose delivery. A sensed element is attached to the dose setting member and includes surface features detectable by the rotation sensor. The rotation sensor comprises a following member including a contact portion resting against and spring-biased in the direction of the surface features. The contact surface is positioned to move over the surface features during rotation of the sensed element, and the rotation sensor is responsive to the movement of the contact portion over the surface features to detect the rotation of the dose setting member.

An assembly for a drug delivery device and an associated drug delivery device are provided. The device has a drug delivery device housing and a medicament contained in the drug delivery device housing. A clutch is established between the dose knob and the dial link to prevent inadvertent proximal axial movement of the lead screw away from the cartridge piston, which can lead to dosing inaccuracies.