GB630056A - Improvements in printing machines - Google Patents

Abstract

630,056. Printing-machines. FURNIVAL & CO., Ltd., FURNIVAL F. S., and BALL W. F. Nov. 6, 1947, No. 29599. [Class 100 (ii)] A printing-machine is constructed so that the printing-cylinders are separated and the sheet-feed mechanism tripped if a sheet is not fed correctly, or if the electrical driving means for the press is stopped. The control means comprises a pair of electromagnets 13, 25 arranged in series with the driving motor, so that the magnets are normally energized and normally permit the action of front stops a<SP>2</SP> which rise to permit feed of the sheets, and also control mechanism for actuating eccentric bearings 34 to a position in which the printing cylinder C (here shown as an offset roller) is in operative position. The electrical circuit comprises micro switches 4 which are opened if one or more of a series of feelers 1 are permitted owing to incorrect positioning or absence of a sheet on the feed-board a to pass through an aperture 5 in the feed-board a and the consequent breaking of the circuit stops the machine and demagnetizes the magnets 13, 25. The armature 14 of magnet 13 then drops and actuates a lever 15 which trips lever-and-link mechanism 20, 19, 171, the normal function of which is to raise the front stops a<SP>2</SP>, and also to raise fingers 161 through the slots 5 in the feed table a so as to keep the feelers 1 raised when a sheet is not passing under the feelers. The armature 26 of magnet 25 controls the position of a recipocating pawl 27 having curved ends which can engage either a roller 31 or 35 of a lever 32 which is pivoted to a link 33 connected to an eccentric bearing 34 of the cylinder C. When the pawl 27 is held raised by the action of the armature 26 on a projection 30 on the pawl 27, the cylinder C is held in printing position, but when magnet 25 is demagnetized the roller 35 is engaged and the lever 30 moved clockwise to move the cylinder C out of printing position. By means of switches b, bl the machine may be set either so that the feed mechanism is tripped while the printing- cylinders are in contact while inking-up, or the printing-cylinders may be tripped and the feed mechanism operated while setting the feed mechanism. The switches b, b<SP>1</SP> are only effective if a master switch b<SP>2</SP> is closed. The feed mechanism may be tripped by a hand lever 24.