| 摘要 |
<p>988,546. Printing apparatus. TIMSONS (HOLDINGS) Ltd. July 24, 1963 [July 26, 1962], No. 28693/62. Heading B6C. In a rotary offset printing machine in which a web W is simultaneously printed on both sides by printing couples 3, 4 and is subsequently dried by gas flames ejecting from burners 18 in a drying chamber 17, the printing and drying operations are automatically stopped should the web movement cease or slow down from a predetermined speed. The combined offset impression cylinders 3 and the inking forme rollers 10 with their associated inking drums 9 are adapted to be swung away from the web and the associated plate cylinder 4, respectively, by solenoid actuated lever and linkage mechanisms 11, 13 on the receipt of an appropriate electrical signal at a box 12. This signal is derived from an electrical electronic control system 29 which acts in response to the voltage generated by a generator 28 driven through a chain drive from a roller 26 over which the web moves. The control system, which also effects the operation of gas valves 20 in the burner supply conduits 22, comprises a transistorized circuit which causes the relays to be fully energized very quickly. This tends to prevent the chattering and sparking at the relay contacts, which is normally present at the breaking and making voltages in most relay circuits. The system also acts to automatically re-start the printing and drying operations as the web regains its normal and predetermined operating speed. Specification 869,903 is referred to.</p> |
