Abstract: A brake mechanism for controlling a ribbon spool wherein a brake member is disposed in braking relationship with the spool for retarding rotation thereof. The brake member has a brake actuator projecting therefrom. An elongated follower pivotally bears against the spool to follow any decrease in the diameter thereof. The follower has an adjustment member which creates a cammed relationship with the brake actuator for progressively moving same and decreasing the brake torque as the follower pivotally moves in response to a decrease in spool diameter. This adjustment member is positioned to impose either a zero or a minimum torque on the brake member when the spool is empty. When in this empty-spool position, the adjustment member can be initially adjusted in a direction substantially parallel to the radial direction of the brake actuator so as to not affect this zero or minimum brake torque.

Abstract: An imprinter having a single driving device for controlling both the movement of the heated printing head and the intermittent advancing movement of the pigmented ribbon. The single driving device, which preferably comprises a reciprocal fluid pressure cylinder, causes the advancing and retracting movement of the printing head. A motion-transfer mechanism drivingly joins the printing head to the take-up reel for the pigmented ribbon. This mechanism is of the one-way type so as to effect rotation of the take-up reel, and advancement of the pigmented ribbon, only when the printing head is being retracted. This mechanism also employs a lost-motion connection therein so that the rotation of the take-up reel is delayed relative to the initial retraction of the printing head, whereby the printing head is initially moved out of engagement with the ribbon prior to the intermittent advancing thereof.