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 a delivery dose. An injector may include a housing, a cartridge containing a medicinal product, the cartridge being retained within the housing, means for selecting a dose of the medicinal product to be expelled, and means for expelling the selected dose of the medicinal product. The housing may be a unitary housing within which the means for selecting the 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 rod may rotate, ratchet means, a dose dial sleeve, a drive sleeve, a button located on the drive sleeve and rotatable with respect to the drive sleeve, and clutch means which upon depression of the button prevents rotation between the dose dial sleeve and the drive sleeve.
