Reciprocable imprinting apparatus

In an article imprinting apparatus which includes imprinting head means carrying type font means for applying an imprint to the surface of an object, inking cartridge means having an exposed inking surface adapted to be engaged by said type font means during a rest condition whereat a sealed engagement is established between the imprinting head means and the inking cartridge means, drive means for translating said imprinting head means in an imprinting stroke and a return stroke between the rest condition and an imprinting position angularly disposed from said inking cartridge means through a path encompassing approximately ninety degrees of arc, and linkage means including a drive link pivotally mounted at one end to a stationary pivot point and at the opposite end to a movable pivot point, and a drive plunger for actuating said drive link, said imprinting head means being coupled to the movable pivot point whereby to effect the translation and guide means for controlling the rotation of said imprinting head means about the movable pivot point, said imprinting head means being rotated simultaneously with the translation thereof along said path, the improvement comprising said guide means comprising cam and follower means, said follower means being pivotally mounted to said imprinting head means at a location off set from the movable pivot point and movable therewith during translation of the imprinting head means, said imprinting head means being rotatable about the movable pivot point at a constant rotational acceleration relative to the drive link as said imprinting head means is translated along the length of said arc, the rate of change of rotational velocity of the imprinting head means per degree of rotation of the drive link being uniformly accelerated, the velocity of rotation of the imprinting head means being uniform at the locations proximate the ends of said path with the velocity of rotation increasing in accordance with the uniform rotational acceleration to the midpath of the strokes and decreasing under uniform deceleration to a location proximate the end of the path.