Sheet clamp apparatus

A sheet clamp apparatus comprising, in combination:

• a drum around which a sheet is to be wound, said drum having a recess, at one part of its peripheral surface, extending along a generating line of said peripheral surface;
• a single clamp member conformably engageable in said recess substantially flush with said peripheral surface and movable radially outwardly of said drum, said single clamp member having leading and trailing edges;
• means biasing said clamp member to seat in said recess;
• stopping means operable to stop said drum at a predetermined position so that single clamp member is always set at an identical initial position;
• means operable to move said single clamp member radially outwardly of said drum, with said drum stopped at said predetermined position, for introduction of the front edge of a sheet beneath the trailing edge of said single clamp member for clamping of the front edge of the sheet for wrapping of the sheet around said drum upon rotation of said drum;
• and means operable, immediately before said drum finishes one revolution following insertion of the front edge of the sheet beneath the trailing edge of said clamping member, the engage the rear edge of the sheet beneath the leading edge of said single clamping member for clamping of the sheet to the peripheral surface of said drum.