Offset duplicator with master treating means

A rotary duplicating machine having a master cylinder and a treating unit for converting a master while the master is being attached to the master cylinder, comprising:

• selective means operable to drive the master cylinder at a printing speed and at a starting speed;
• feed means for feeding a master to the treating unit;
• conveyor means for transporting said master from the treating unit to the master cylinder;
• clamping means on the master cylinder for clamping one end of the master to the master cylinder;
• said drive means driving the feed means and the conveyor means at a speed to move a master at substantially the same speed as moved by the master cylinder when operating at its starting speed, and
• control means for rendering the drive means inoperative when the clamping means clamps one end of the master to the master cylinder.

In a lithographic duplicating machine having a master cylinder, a feed means for feeding a master to a treating unit in a path to the master cylinder, said treating unit serving to convert the master by a conversion fluid, clamping means on the master cylinder and selectively operable in master eject and master clamp modes, and conveyor means in the path for transporting one end of the master from the treating unit to the clamping means on the master cylinder, the combination which comprises:

• switching means operable from a first mode for rotating said master cylinder at a printing speed, to a second mode for rotating said master cylinder at a starting speed;
• means for controlling the operation of the feed means and the conveyor means at a speed to move a master at substantially the same speed as moved by the master cylinder when rotating at the starting speed;
• said control means including a first part controlling operation of the feed means and operable to discontinue operation of the feed means and operate the conveyor means when said one end of the master arrives at the conveyor means;
• and
• a second part interconnected with the switching means for discontinuing the operation of the conveyor means when the clamping means is operated to the master clamp mode, whereby the master is drawn through the treating unit while it is being wrapped around the master cylinder during rotation of the master cylinder at the starting speed;
• and
• means for causing the master cylinder to operate at the printing speed when the master is wrapped completely around the master cylinder.

A method of treating a master with a conversion solution while the master is being attached to a master cylinder of a duplicating machine in which the master cylinder is selectively operable at a printing speed and a starting speed, comprising the steps of:

• transporting a master to a treating means by feed means operable at the starting speed of the master cylinder;
• discontinuing transport of the master by the feed means in response to arrival of one end of the master at conveyor means;
• operating the conveyor means for delivering said one end of the master to a clamping means on the master cylinder;
• discontinuing the drive of the conveyor means when said one end of the master is clamped to the master cylinder by the clamping means;
• operating the master cylinder at the starting speed to draw the master through the treating means while the master is being wrapped around the master cylinder;
• and
• operating the master cylinder at the printing speed when the master is wrapped completely around the master cylinder.

A duplicating machine including master clamping means, comprising:

• a master cylinder for supporting a master and rotatable selectively at a printing speed and a starting speed;
• a cam disc interconnected with the master cylinder and provided with an outer periphery having a first and a second timing surface;
• follower means carried by the master cylinder for coaction with the cam disc;
• said clamping means being positioned on the master cylinder and operable from an open position for ejecting a master to a closed position for master clamping, and through a master inserting position intermediate the open and closed positions;
• and
• actuator means for operating the clamping means to the open position when the follower means coacts with the first timing surface of the cam disc and for operating the clamping means to the master inserting position when the follower means coacts with the second timing surface of the cam disc,
• said actuator means operating the clamping means from the master inserting position to the closed position when the said follower means coacts with the periphery of the cam disc spaced from the first and second timing surfaces.

A duplicating machine, comprising:

• a master cylinder having a clamping means thereon for clamping one end of a master to be attached to the master cylinder;
• a treating unit for converting the master while the master is being attached to the master cylinder;
• feed means operable to transport the one end of the master through the treating unit to a conveyor means operable for delivering the one end of the master to the clamping means;
• means for operating the master cylinder from a printing speed to a starting speed upon operation of the feed means;
• means for discontinuing operation of the feed means and for operating the conveyor means when said one end of the master arrives at the conveyor means;
• and
• means for discontinuing operation of the conveyor means when the clamping means clamps said one end of the master to the master cylinder.