Variable speed linkage

Claim 1

IN APPARATUS OF THE TYPE DESCRIBED, A SUPPORT, A SLIDE UNIT MOUNTED FOR REVERSING SLIDING MOVEMENT ON SAID SUPPORT, A LINKAGE TO OPERATE SAID SLIDE UNIT AT VARYING SPEEDS IN DIFFERENT PHASES OF SAID MOVEMENT, SAID LINKAGE COMPRISING A PRIMARY ACTUATOR OPERATIVELY ENGAGING SAID UNIT, SAID ACTUATOR HAVING A PIVOTAL AXIS ON SAID SUPPORT AND HAVING A FIRST PORTION TO ENGAGE AND OPERATE SAID UNIT AT A GIVEN SPEED IN ONE OF SAID PHASES, AND A SECOND OPERATED PORTION TO BE OPERATED, A SECONDARY ACTUATOR OPERATIVELY ENGAGING SAID SLIDE UNIT AND HAVING A PIVOTAL AXIS ON SAID SUPPORT IN PARALLEL BUT TRANSVERSELY SPACED RELATION TO THE PIVOTAL AXIS OF SAID PRIMARY ACTUATOR, SAID SECONDARY ACTUATOR ALSO HAVING A PORTION TO ENGAGE AND OPERATE SAID UNIT AND A FURTHER PORTION PROVIDING AN OPERATING CONNECTION FOR ACTUATION BY SAID PRIMARY ACTUATOR, WHICH FURTHER PORTION IS TRANSVERSELY SPACED FROM THE PIVOTAL AXIS OF THE PRIMARY ACTUATOR, THE MOMENT ARM DISTANCE FROM SAID PRIMARY ACTUATOR AXIS TO SAID FURTHER PORTION BEING SUBSTANTIALLY DIFFERENT FROM THE DISTANCE FROM SAID PRIMARY ACTUATOR AXIS TO ITS SAID SECOND OPERATED PORTION, SAID ACTUATORS THUS COACTING IN OPERATING THE SLIDE UNIT AT A DIFFERENT SPEED IN ANOTHER OF SAID PHASES, AND AN AUTOMATICALLY CYCLING DRIVE DEVICE ENGAGING SAID PRIMARY ACTUATOR AT SAID SECOND OPERATED PORTION OF THE LATTER TO PROVIDE REPEATED VARIABLE SPEED MOVEMENT OF THE SLIDE UNIT OVER THE DIRECTION OF THE TWO PHASES.