GB191317081A - Improvements in Printing Presses. - Google Patents

Abstract

17,081. Marks, E. C. R., [Kandle-Born Co.]. July 25. Throw - out arrangements.- Relates to apparatus for use in printing - machines whereby if a sheet is not fed correctly up to the gauges, an electric circuit is completed, the machine is tripped, and the sheet returned over the feed-board. Above the impression cylinder 11 is located a shaft 13 carrying arms 14, to one of which is adjustably secured a bracket 15. Mounted in the bracket 15 is a friction roller 16 which is normally clear of the cylinder 11 but capable of movement into contact therewith if a sheet is improperly fed. At the other end of the brackets 15 is a shaft 24 carrying two rollers 25 capable of being lowered into contact with the feed-board 10 and driven by chain 18 and spur gearing from a sprocket - wheel on the roller 16. The up- and-down movement of the bracket 15 with the rollers 16, 25 is effected by means of an arm 33 on a rod 29, reciprocated vertically by an arm 30 and a cam 51<1>. The bracket 15 carries a shaft 35 on which is an arm 34 resting in contact with the arm 33, an arm 36 connected by a link 38 to a plunger 39 sliding in guides in the bracket 15, and an arm 37 adapted to contact with an adjustable stop 42 to limit the pressure of the rollers 25, 16 respectively on the feedboard 10 and impression cylinder 11. The rollers 25 are adjustable independently of the rollers 16. In the normal operation of the machine, descent of the rod 29 is prevented by a stop 49 sliding axially in the main frame. If a sheet is incorrectly fed, a circuit is completed through contacts 110 and a timing-contact on the cam 51<1> and the stop 49 withdrawn, whereby the rollers 25 are lowered on to the feed-board 10 and the mis-fed sheet returned over the board. The stop 49, Fig. 11, is surrounded by a spring 54, which tends to retract it, but is normally held forward by a latch 65, bearing a roller 66, which, when the latch is held raised by the armature 55<1> of the electro-magnet 55, engages the head 81<1> of a lever 81, and causes the arm 77 to eject the stop 49. The latch is reset by a roller 75 which engages a cam 63 on the main gear 56. The shaft 68 carrying the arms 77, 81 is furnished also with a crank resting behind the lever 70, which is operated by a cam on the face of the gear 56 to control the movement of the impression cylinder into and out of contact with the type. When the magnet 55 is excited, the crank on the shaft 68 allows the lever 70 to move inwards against the cam, so that when no sheet is present, the impression cylinder is moved out of contact with the forme.