Hammer timing means in a high speed belt printer

Claim 1

PRINTING APPARATUS COMPRISING THE COMBINATION OF A PAIR OF SPACED ROTATABLE ELEMENTS, A FLEXIBLE ENDLESS BELT EXTENDING IN A LOOP AROUND SAID ROTATABLE ELEMENTS, SAID BELT HAVING TYPE CHARACTERS THEREALONG, SAID BELT FORMING TWO STRANDS EXTENDING BETWEEN SAID ROTATABLE ELEMENTS, MEANS FOR MOVING ONE OF SAID STRANDS THROUGH ITS LENGTH AT A CONSTANT SPEED, A PLURALITY OF PRINTING DEVICES SPACED ALONG THE OTHER OF SAID STRANDS FOR EFFECTING IMPRESSION OF SELECTED ONES OF THE TYPE CHARACTERS LOCATED ON SAID OTHER STRAND ONTO A RECORD MEDIUM, MEANS FOR CONSTANTLY MOVING THE CENTERS OF SAID ROTARY ELEMENTS IN CIRCULAR PATHS WHEREBY TO CAUSE SAID OTHER STRAND TO MOVE SAID TYPE CHARACTERS THEREON AT VARYING SPEEDS PAST SAID PRINTING DEVICES, AND MEANS FOR ACTUATING AT LEAST CERTAIN OF SAID PRINTING DEVICES WHEN SAID FIRST STRAND IS MOVING AT MINIMUM SPEED.