Improvements in or relating to Printing Presses

3795. Morse, W. S. Feb. 13. Feeding and registering webs.-The speed of rotation of the shaft of the web-supply roll of a printing-press is governed by means of a braking-device having an independent driving- device, which is normally inactive but is rendered active automatically by variations in the web tension by means of a movable member bearing against the web. The braking-device is preferably operated and controlled electrically, but may be controlled mechanically by means of gearing and a clutch which is operated by the movements of the member in contact with the web. Fig. 1 shows the invention applied to a double-deck printing-press, each deck having three supply rolls R and feeding a web to separate printing-couples. The shaft 11 of each roll is provided with a grooved brake wheel 12 engaged by brake shoes 13, 13 carried by levers 14, 14' pivotally connected at their lower ends to a bar 15 pivoted on a spindle 16 on the machine frame. The upper ends of the levers 14, 14 are connected by a spindle having right and left hand threads and provided with a hand-wheel 19, by turning which the normal pressure of the brake may be adjusted. The pivot connecting the lever 14 and bar 15 engages a slot in the bar 15 to permit a limited independent movement of the lever 14 under the action of an arm 21 of a bell-crank, the arm 21 engaging an extension 20 of the lever 14. The other arms 23 of the bell-cranks are connected to a link 24 operated by an electric motor 25 through gearing and linkage. Indicators 34 actuated by a connexion from the brake-actuating mechanism are provided to show that the mechanism is operating properly. The web 36 from the active roll on the upper deck passes over a spring-pressed compensating- roll 37, guide-rollers 41, and a tension-controlling roller 42 adjacent to the printing- couple. The roller 42 is carried by bell-cranks L, to one of which is pivoted a rod 51 mounted in guides 511, 512 and carrying a spring 50, bearing at one end against the guide 511 and connected at its other end to a slidable collar 52, the position of which may be adjusted by a handle 53 pivoted to the collar 52 and connected by a link 54 to an arm fixed to the rod 51. The handle is held in adjusted position by a spring pin 57 engaging holes in a member 56 pivoted to the arm 55. A modification of this spring-adjusting device is shown in connexion with the web 36 from the lower deck. The spring 57 bears against a loose collar 62 which can be moved along the rod