Patent GB-638631-A (GB)
Title: Improvements in or relating to machines for perforating strip for controlling composing and typesetting machines
IPC: B41B25/00
Filed: 1947-03-19
Abstract: 638,631. Strip - perforating machines. CROUCHER, H. G. March 19, 1947, No. 7569. [Class 100 (iii)] In a pneumatically-operated machine known by the Registered Trade Mark " Monotype," or a such-like machine of the kind in which a web or ribbon of paper is punched with perforations for controlling typesetting or casting operations, the normal operation of the machine is automatically interrupted and/or a warning signal is given, by the action of a detector when a predetermined minimum of paper remains for perforation. Air from a supply hose 9, Fig. 1, is admitted to the paper tower cylinder 3 containing the paper punchings, through a bore 8c, port 8a, annular recess between the two pistons of a valve 7, port 8b, tube 11 and nozzles 11a, when the valve is moved upwardly against a spring 7b in its cylinder in a housing 8, to disturb the punchings and force them through a hose 5 into a container 4 having a gauze bottom 4a. The valve is moved upwards by an arm 14a on a bar 14 intermittently reciprocated by the bell-crank lever 12 of the reversing valve piston 13 of the typesetting machine, or by the piston operating the restoring rocker arm thereof. The detector comprises a roller 15 mounted on a cranked member 15a on a rod 15b and is held against the surface of the supply roll 16 by a pivoted arm 17 actuated by a piston 8f forced down by air admitted from the bore 8c through a passage 8e controlled by a spring 10. The member 15a can be turned at right angles to bring the roller 15 out of contact with the roll surface. As the roll diameter decreases, the arm 15b rises, carrying with it a trigger 18, and at the desired diameter a slot 18a in the trigger comes into line with a stud 20b projecting from a stop-bolt 20, which is then pulled by a spring 20a to the right so as to lie across the path of the bar 14 and stop the operation of the machine. Just before or as the stop bar is released, a pin 17b abuts a contact 22 to light a warning lamp 21, or a gong may be arranged to be struck by the released bolt as an audible signal. On lowering the arm 15b to insert a new roll, a resilient cam rail 19a urges a roller 20c on the bolt to the left, so that when the top of the trigger 18 passes below the stud 20b the bolt is retracted in readiness for its next actuation. In another form, Fig. 3, the roller 15 is mounted on a pivoted arm 24 having a trigger lever 24a abutting the end of a stop bolt 25 which when released is spring-urged to the left over the bar 14. Alternatively, the detector may bear by gravity on the upper side of the roll or be counterweighted to engage the circumference, or may be spring or gravity loaded to contact an-end of the roll so as to move inward when the minimum radius is reached. In another form the detector may operate on the web itself so as to be released when the web runs off the roll, in which case the path of travel of the web to the tower is increased to leave sufficient paper to attach to the new web. The bar 14 could be attached to some other periodically actuated part of the machine than the piston 13. If it is desired only to give a warning signal, the stop bolt 20 and trigger 18 are omitted. According to the Provisional Specification the valve 7 may have a transverse bore instead ofan annular passage, and the piston may have a rotary motion to align the bore with the ports 8a, 8b. Instead of preventing the movement of the piston 13, the supply ducts to the keyboard driving cylinders could be blocked or diverted. The warning signal may comprise a bell, buzzer, ribbon or flag.