GB388741A - Improvements in and relating to rotary printing presses - Google Patents

Abstract

388,741. Printing-machines. CRABTREE & SONS, Ltd., R. W., Victoria Works, Water Lane, PHYTHIAN, T. E., 25, Headingley Mount, Headingley, and CRABTREE, C. H., Victoria Works, Water Lane, both in Leeds. July 31, 1931, Nos. 21954 and 21955. [Classes 100 (i) and 100 (ii).] In a rotary web-printing press having a number of electrical contacts distributed along the path of the web whereby, upon breakage of the web, electro-magnetic devices are rendered operative to control various elements of the press, the circuits of the electro-magnetic devices are closed by a relay in circuit with the webcontrolled contacts. The contacts shown in the Figure comprise fixed studs f and spring- pressed studs f<1> on opposite sides of the web b, the studs being arranged in a low-voltage circuit which includes a relay coil g. This circuit may be supplied by a battery or from the mains h through a resistance arranged at h<1>. Upon breakages of the web, this circuit is completed and the coil g energized to close circuits from the mains h through solenoids e, t<2>. The solenoid e is adapted to operate a device for gripping and tearing the web before it reaches the impression cylinders to prevent a " winder." This device may comprise an arm a<1> fixed to a shaft a and carrying a bar a<2> provided with a rubber insert a<3> adapted, when the shaft a is turned by an arm a<4> connected to the core e<1> of the solenoid e, to grip the web against a fixed bar c. In a modified form of gripping device, the arm a<1> is moved to gripping position by a spring normally held inoperative by a catch which is released by the solenoid. The solenoid t<2> serves to throw the ink-distributing rollers out of contact with the inkdistributing drum by closing a clutch s<3>, s2 on the shaft s of the distributing drum to turn, through chain gearing s<1>, q<9>, q<8>, a shaft q<4> operatively connected to the frame supporting the distributing rollers. The movement of the shaft q<4> is arrested when the distributing rollers are tripped by means of a cam q<6> which acts upon a lever v<2> to open a switch v<1> in the circuit of the solenoid t<2> and allow the clutch s<3>; s<2> to be opened by a spring t<3>. The movement of the shaft q<4> may also render the ink-fountain roller inoperative in the manner described in Specification 363,745. The relay coil g may also be adapted to close or open. contacts l in the circuit of the press-driving motor to stop the press, and may also close other circuits containing solenoids for applying a brake to the web-supply roll of the press and for tripping the impression cylinders. The web-controlled contacts may comprise, instead of studs f, f<1>, a roller on one side of the web and a co-operating spring-pressed roller or spring tongue on the other side of the web.