FIELD: medical equipment.
SUBSTANCE: invention relates to medical equipment, specifically to a drug delivery device, such as a pen-type injection device, which provides administration by injection of medical products from a cartridge with multiple doses. Drug delivery device has a housing containing repeatedly installed dose setting mechanism; cartridge holder to receive cartridge containing at least one medical product; and means for detachable connection of cartridge holder with housing or dose setting mechanism. Dose setting mechanism comprises a piston rod and drive. Means for detachable connection of cartridge holder with housing or dose setting mechanism are adapted and arranged so that, initial rotary connecting movement of cartridge holder or dose setting mechanism causes movement of cartridge holder in a first axial direction relative to housing or dose setting mechanism. Means for detachable connection of cartridge holder with housing or dose setting mechanism is additionally adapted and arranged so that extending rotary connecting movement of cartridge holder or dose setting mechanism causes movement of cartridge holder in a second axial direction, that is opposite to first axial direction, or dose setting mechanism. Drive has two drive components, which are connected to each other with possibility of rotation when setting dose and dose delivery and which are separation from each other with possibility of rotation during repeated installation of dose setting mechanism. Coupling transmission is provided for connection and disconnection of two drive components. For separation of two drive components, relative axial movement between two drive components is required. Provided is a spring mechanism, deflecting two drive components in connected position. Spring force is overcome at application of force to piston rod in first axial direction, causing separation of drive components.
EFFECT: invention is not a cumbersome and ensures accurate and reliable operation.
15 cl, 7 dwg
