GB968082A - Automatic paper reel joining machine - Google Patents

Abstract

968,082. Feeding webs. SCHNELLPRESSENFABRIK KOENIG & BAUER A.G. Dec. 29, 1960 [Feb. 17, 1960 ; Nov. 26, 1960], No. 44678/60. Heading B6B. A reel changing device, particularly for rotary printing presses, is provided with a rotatable roll spider and automatic control of the operation of joining the replacement roll to the expiring web. A control impulse is emitted to initiate rotation of the roll spider and therewith the whole cycle of the reel joining operation when the difference between the rotational speeds of the expiring roll and press reaches a predetermined value which is substantially constant for the operating range of speeds of the press, such that a predetermined constant diameter of waste roll remains after the completion of a reel changing operation. An endless belt 4, Fig. 1, is driven by a pulley 6 through a variable speed gear 7 to accelerate a replacement roll 5. The gear 7 also drives a generator 8. The arms of a roll spider carry generators 9, 10 and 11 driven by the respective rolls at speeds determined by the diameter of such rolls. In the position shown, web 2 is being unwound from an expiring roll, while the corresponding generator 9 is electrically coupled to the generator 8. When the speeds of the generators 8 and 9 differ by a predetermined amount an electric impulse is produced which initiates a web-splicing operation which includes rotation of the roll spider, acceleration of the replacement roll 5, glueing by a brush 13, and cutting of the expiring web by a knife 14. In a modification, the diameter of the expiring roll 3, Fig. 3, is detected by a scanning device 21 comprising a light source 22 and a receiver 23, e.g. a photo-electric cell which reacts to light reflected from the roll 3. The device 21 is displaceable in a guide 24 depending on the speed of the machine supplied with web. The device is actuated by a bell-crank lever 28, 29 by a cam 25 engaging a follower 27 held in engagement with the cam 25 by a spring 33. The cam 25 is secured to a shaft 34 of a motor 35. A tachometer generator 39 is driven by the machine supplied and produces a voltage proportional to its speed which is supplied to the motor 35. The motor rotates the cam 25 into an appropriate position against the action of a spiral spring 40. Should the speed of the machine increase, the cam 25 causes the device 21 to be appropriately adjusted in position to react to a different diameter of the roll 3, e.g. a larger diameter if the machine increases in speed. When the diameter of the roll 3 has been sufficiently reduced reflected light from the source 22 is no longer reflected to the receiver 23, thereby causing the initiation of a splicing operation. The device 21 may be replaced by a mechanical or electrical sensing device for sensing the diameter of the roll 3. The generator 39 and motor 35 may be replaced by a centrifugal governor driven by the press and actuating the cam 25.