The invention relates to an injection unit, preferably a pen-shaped injection unit, for administering or delivering a fluid product. The injection unit comprises a housing, an axially movable piston rod mounted in the housing in a non-rotatable manner, a delivery apparatus having a threaded nut that is able to move the piston rod in order to deliver product, a dosing device having a dosing sleeve, a rotary knob, a discharge button arranged coaxially on the dosing sleeve, and a receptacle for the product. The dosing device is connected to the delivery apparatus via a coupling mechanism, wherein the coupling mechanism includes of at least two coupling surfaces that each carry a toothing comprising teeth, wherein the coupling surfaces are used to generate an acoustic and/or tactile signal corresponding to the set or corrected dose of the product to be administered during the dosing operation or during correction of the dose.

A drive mechanism for a drug delivery device with a reduced operating loudness includes a dose selector, a housing, and a ratchet with a gear element comprising a plurality of gear teeth connected with the dose selector and a pawl element rotationally constrained to the housing comprising at least one pawl tooth. The at least one pawl tooth engages with the gear teeth and is located opposite to the gear teeth. One of the gear element and the pawl element moves forth and back relative to the other element of the gear and pawl elements along a first direction for de-engagement and re-engagement of the opposite gear teeth and at least one pawl tooth when the gear element rotates relative to the housing during dose setting using the dose selector. The pawl element and/or gear element comprises a noise reduction characteristic at a surface which dampens the noise produced.

A dosing device for an injection device, the dosing device including an actuating element for adjusting and/or dispensing a dose from the injection device, a thrust element for generating a forward movement for discharging a dose and a coupling to which the actuating element and the thrust element are coupled such that a rotational movement of the actuating element is transmitted directly to the thrust element and an axial movement of the actuating element is different than an axial movement of the thrust element.

The present disclosure relates to a drive mechanism which is suitable for an injection device, especially a pen type drug delivery device and to such a drug delivery device. The mechanism comprises a spring driven rotatable drive member, a rotatable driven member, a clutch rotationally coupling the driven member and the drive member in a coupled state and allowing relative clockwise and anti-clockwise rotation between the driven member and the drive member in a decoupled state, and a spring biasing the clutch into its coupled state and allowing relative axial movement between the drive member and the driven member into the decoupled state of the clutch against the bias of the spring. The clutch comprises a first ring of crown teeth on the drive member and a second ring of corresponding crown teeth on the driven member with each crown tooth having in the clockwise and the anti-clockwise direction different ramped tooth angles such that the teeth are allowed to override each other in the de-coupled state of the clutch with a different resistance in the clockwise and the anti-clockwise direction.

The present disclosure relates to a drug delivery device comprising: a housing; a moveable number sleeve disposed within the housing and having numbers printed thereon; and a transparent window occupying an aperture of the housing and covering the number sleeve such that the number sleeve is visible through the transparent window. At least one region of the housing located adjacent to the transparent window is transparent to visible light and is in optical communication with the transparent window.

A fluid delivery device has a syringe barrel-type reservoir with plunger and plunger driver assembly comprising nested, telescopic screws comprising an innermost screw keyed to a first side of the plunger or intermediate pusher to prevent rotation. In a fully retracted position, the nested screws do not extend into the reservoir. The nested screws all have right handed threads and employ the same pitch in their respective inner thread and outer thread designs. The outermost screw is connected to a motor for controllable rotation. The decreasing torque ratios from the outermost to innermost screw member and anti-rotation feature allows the innermost screw to advance the plunger into the reservoir before the adjacent concentric screw member commences rotating and advancing within its corresponding screw, and so on, to translate the plunger and expel fluid in a fluid chamber defined on the other, second side of the plunger.

An assembly for a drug delivery device is provided comprising a housing, a cartridge holder releasably connectable to the housing, a resilient member, and an interaction member which is configured to mechanically cooperate with the resilient member and with the cartridge holder. The resilient member is configured to rotationally bias the interaction member. The assembly has a locked state where the cartridge holder is connected to the housing, the cartridge holder being obstructed from movement with respect to the housing, and an unlocked state where the connection between the cartridge holder and the housing is released, the cartridge holder being freely moveable with respect to the housing.

The present disclosure is generally directed to a drug delivery device for selecting and dispensing a number of user variable doses of a medicament. The device comprises a housing, a dose selector operable to set a dose by rotation relative to the housing, a number sleeve arranged within the housing, a drive sleeve which is rotationally constrained to the housing during dose setting and dose correcting and which is rotatable relative to the housing during dose dispensing, a piston rod coupled to the housing and to the drive sleeve a drive spring arranged between the housing and the number sleeve, and a ratchet operatively arranged between the drive sleeve and the number sleeve. According to the disclosure the ratchet comprises at least one clicker arm of one of the number sleeve and the drive sleeve and ratchet teeth of the other of the number sleeve and the drive sleeve.

A fluid injector system for delivering a multi-phase fluid injection to a patient and methods of fluid delivery is disclosed. Methods of creating and using a multi-aspect fluid path impedance model of the injector system are used. Modeling and adjustment of factors that affect impedance and prevent or reduce backflow, reduce the likelihood of fluid flow rate spikes and provide more accurate flow rates and mixing ratios of fluids may be repeated or happen essentially continuously during an injection. The adjustments may be determined before the injection or determined and/or adjusted during the injection. The determination may include sensor feedback commonly used in injectors such as pressure and position feedback as well as other sensors. In all cases, the user can be notified of adjustments through on-screen notices and/or through the recordation of the injection data by a control device of the injector at the conclusion of the injection.