GB190927276A - Improvements in Apparatus for Etching Printing Plates. - Google Patents

Abstract

27,276. Matteson, W., and Gould, T. B. Nov. 23. Etching.-The plate is carried on a tray 2 in a bath 1 provided with lids 6, 7, the former of which is supported by a frame 10 pivoted on the driving- shaft 12. In bearings on the frame 10 are mounted the shafts 11 of the propellers 5, which are driven by a chain 24 from a shaft 22 driven by bevelgearing 21 from the main shaft 12. The frame 10, with the parts attached thereto, is c o u n t e rbalanced by weights 14<a>, 14b on a. chain 13. The tray 2 is supported by links 3, 4 connected to links 45, 44 pivoted to brackets 9, 8 on the lid 7 and the frame 10 respectively. When the lid 6 is raised, the end thereof engages a roller 35 on the lid 7, tilting the lid and lifting the tray 2 to a position clear of the fluid at the top of the bath 1. To hold the lids in the raised position, a rod 38 is pivoted on a bracket 37 on the lid 7 and is provided with a recess 39 adapted to engage a pin 40 projecting from the lid 6. When the lids are closed, they are secured by an arm 15 which engages the projecting end of the lid 6, and which, by its movements to lock or unlock the lids, operates the belt-shifter 19 of the driving belt. Further, to ensure that the propellers shall not be started until the lids are closed, a lever 41, operated by the counterweights 14<a>, 14<b>, locks the belt-shifter when the lids are open. To distribute the action of the fluid evenly over the surface of the plate, the tray 2 is given a rocking motion by a rod 32, which is recessed to engage a cross-bar 33 attached to the upper end of the levers 3 and is reciprocated by a crank 31 driven by friction gearing 29, 30 from the shaft 12. When the lids are raised, the rod 32 is disengaged from the bar 33 and is supported by a bracket 34. Vertical baffle-plates 43 are attached to the underside of the lid.