The assembly method of the invention uses a cartridge that is separate from the housing of the device being manufactured. The direct-drive electric machine is configured with a plural-module combination structure in which the rotor or the mover and the stator are mutually combined such that a plurality of modules form one phase, respectively. Structure engageable between the fork and the opening lever decouples the opening lever from the drive on displacement of the fork from the open to the closed position.