Electronic stencil cutter

Apparatus for holding an original subject sheet or the like about the cylindrical surface of a drum comprising;

• a backing sheet wrapped about the drum;
• a transparent retainer sheet wrapped about the drum exteriorly of the backing sheet and adapted temporarily to retain an original subject sheet on the backing sheet in a scannable position visible through the retainer sheet;
• clamp means gripping fixed ends of said retainer and backing sheets extending substantially parallel to the axis of the drum;
• fastening means attaching said clamp means to the drum, said fastening means including means enabling limited angular adjustment of said clamp means relative to the axis of the drum in response to tensioning the retainer sheet about the drum to enable wrinkle-free disposition of the sheets about the drum;
• said retainer sheet having a free end opposite the fixed end, thereof, and pressure-sensitive adhesive means at said free end attachable to the surface of the drum by pressure applied thereto, said adhesive means being releasable by pulling said free end away from the drum to provide access to said scannable position for removing and replacing a copy sheet.

Apparatus for holding a stencil or like sheet wrapped about the cylindrical wall of a drum comprising;

• said cylindrical wall having an elongated slot parallel to the axis thereof;
• an elongated clamp bar of size and shape to fit within said slot;
• guide means on said drum supporting said clamp bar for movement between a closed position within said slot, and an open position outside of said slot providing a gap between the bar and drum sufficient to insert a sheet;
• first spring means urging said clamp bar outwardly toward its said open position;
• a pair of latch members mounted within said drum at opposite ends of said clamp bar for movement between latched and unlatched positions;
• second spring means urging said latch levers toward their said latched positions;
• said latch members while in their latched positions having bottom surfaces overlying top surfaces of said clamp bar when the latter is in its said closed position to thereby lock said clamp bar in its said closed position, said latch members while in their unlatched positions having end portions urged by said second spring means into abuttable relatively slidable engagment with side surfaces of said clamp bar when the latter is in its said open position to thereby automatically hold said latch members in their said unlatched positions while enabling said clamp bar to be moved toward its said closed position by pressing said clamp bar inwardly into the drum against the urgence of said first spring means;
• and
• said latch members being automatically movable into their respective latched positions by said second spring means in response to pressing said clamp bar into its said closed position.