Patent attributes
The present invention relates to injectors, such as pen-type injectors, that provide for administration of medicinal products from a multidose cartridge and permit a user to set the delivery dose. The injector may include a housing, a cartridge containing medicinal product, the cartridge being retained within the housing, means for selecting a dose of medicinal product to be expelled, and means for expelling the selected dose of medicinal product. The housing may be a unitary housing within which the means for selecting a dose and the means for expelling the selected dose are moveably retained. Alternatively, the injector may include a housing, a piston rod, an insert located in the housing and through which the piston may rotate, a ratchet, a dose dial sleeve, a drive sleeve, a button located on the drive sleeve and rotatable with respect to the drive sleeve, and a clutch which upon depression of the button prevents rotation between the dose dial sleeve and the drive sleeve.
