GB1147928A - Improvements in or relating to a writing head producing a jet of ink - Google Patents

Abstract

1147928 Recording-apparatus. S A PAILLARD 16 Jan 1968 [13 Feb 1967] 2334/68 Index B6P 9A6 A writing head comprising a body 1 carrying a tube 9 constituting a nozzle for ink forming a jet which can be deflected by electrodes 24, 24', 25 and 25' and comprising a disc shaped partition 11 perpendicular to the axis of the jet and located between the nozzle and the electrodes with an opening 12 coaxial with the jet is characterized by providing a sharp edge along the periphery of the opening 12 with the surfaces of the partition 11 leading to the sharp edge polished to prevent the deposit of ink droplets along or near the edge. The sharp edge of the opening 12 merges into the flat surface of the partition 11 through an annular convex surface 11a and a radial groove 29 extends downwardly to guide any droplets that settle on the partition 11 to an output port opening into a tube 28. As shown, the body 1 is made of metal and slidably supports an insulating member 3 moulded to include a partition 5 with air holes 6 and a coaxial member 7 carrying the tube 9 which is fed with conductive ink through a flexible pipe 10 and receives voltage either through the ink or by a metal lead, which may be inserted through the pipe 10. The electrodes are shown constructed and supported as in Specification 1147927 the insulating rings 21, 22 being supported by four projections 13, 14, 15, 16 of the metal body 1 threaded internally to receive a metal member 18 adapted to clamp a metal securing lug 20 between a metal ring 19 and the ring 21. The electrodes and tube 9 are effectively screened from static charges which may collect on the insulating parts and the metal parts 1, 20 and 18 are subjected to the same voltage as a support carrying the surface to be written on by the jet.