Apparatus for positioning a pad or book of sheets on the work table of printing apparatus

Apparatus for the positioning of a loose leaf or bound pad or book on the work table of an apparatus for printing the individual leaves of the pad or book comprising a holder member which cross-section is of an inverted channel configuration, said holder member being disposed to extend traversely of the work table and located along one end of the work table and movable in a plane normal to the upper surface of the work table by being guided for upward and downward movement in a substantially vertical stand between a raised inoperative position which allows introduction of a pad or book between the holder and the work table and a lowered operative position in which said holder member can contact and hold the pad or book securely in its position on the work table, in which the work holder is acted upon by a spring, one end of which bears on the upper face of the work holder while its other end is braced on the bottom of a recess provided in the stand, the work holder being urged downwardly by the spring into the operative position, a reciprocating actuating lever for moving said holder mounted for traverse movement in the front of the stand, said lever being displaceable against the action of said spring to move the work holder upwardly into its inoperative position, in which position said lever is held by means of a locking lever which cooperates with the actuating lever, said actuating lever having at one end an actuating grip while its other end, which is on the other side of the hinging point of the lever on the stand, is activated on a guide pin connected to the work holder, and a plurality of moveable positioning studs for locating the position of the pad or book on the table, said studs being disposed both on a line extending longitudinally of the work table as well as on a line extending traversely of the work table and located to one side of the work holder, the positioning studs so co-operating with the work holder that in the operative position of the work holder they are disposed in a downwardly depressed inoperative position, while when the work holder is in its inoperative position, they are in their operative position in which they project upwardly from the work table to position a pad or book in the correct position on the work table.