Apparatus and method for handling media sheets in a photo-plotter

A method for handling a media sheet in a system for photo-plotting and handling said media sheet and including a drum with an internal drum support surface for said media sheet, said method comprising the steps of:

• transporting said media sheet to said drum with a media carriage;
• positioning said media sheet on said drum support surface of said drum such that a plurality of registration pins each being extended from a corresponding plurality of aligning means disposed on said media carriage to pass through a plurality of mounting features and fit into a corresponding plurality of drum openings formed within said drum support surface of said drum;
• and
• sensing a position of said registration pins relative to said aligning means.

A system for photo plotting and handling a media sheet, said system comprising:

• a photo-plotter having a drum with a drum support surface, said drum support surface having a plurality of drum openings formed therein;
• a media handler being disposed adjacent to said photo-plotter, said media handler having a positioning means for picking-up and transporting said media sheet, said positioning means having a plurality of aligning means with a corresponding plurality of registration pins, said aligning means having an engaged position and a disengaged position, in said engaged position said plurality of registration pins passing through a plurality of mounting openings formed within said media sheet and to fit in said plurality of drum openings for proper positioning of said media sheet in said drum;
• and
• a sensor for detecting a position of said registration pins relative to said aligning means.

A system for photo-plotting and handling a media sheet, said system comprising:

• a drum having a drum support surface and a plurality of drum openings formed therein;
• a media sheet supply station having a supply of said media sheets;
• a punching means disposed between said media sheet supply station and said drum for punching a plurality of mounting features within said media sheet;
• a media carriage for transferring said media sheet from said media sheet supply station to said punching means and from said punching means to said drum support surface;
• a plurality of suction gripper elements disposed on said media carriage and actuable by vacuum to grip said media sheet when transferring said media sheet from said supply station to said punching means and when transferring said media sheet from said punching means to said drum support surface;
• and
• a plurality of aligning means disposed on said media carriage and having an engaged position and a disengaged position, each of said plurality of aligning means having a registration pin with an extended position and a retracted position, corresponding to said engaged and disengaged positions of said aligning means, each said registration pin having a free bull-nose portion and a location defining portion following said bullnose portion;
• means for operating said aligning means to move said pins to their extended position prior to said media sheet reaching said drum with said plurality of mounting features of said media sheet are positioned on said pins;
• and
• means operable when said media sheet reaches said drum support surface for first inserting said bullnose portions of said pins into said drum openings sufficiently to prevent said media sheet from falling from said pins, for then releasing the vacuum holding said suction gripper elements to said sheet, and for then further inserting said pins into said drum opening until said location defining portions of said pins are received in said drum openings to precisely position said media sheet relative said drum support surface.