Patent GB-906946-A (GB)
Title: Thermionic valve assembly machine
Inventor: JACKSON THOMAS
IPC: H01J19/46
Filed: 1960-04-04
Abstract: 906,946. Turret machines for assembling thermionic valve electrode structures. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. March 27, 1961 [April 4, 1960], No. 11847/60. Class 39 (2). [Also in Group XXX] A machine for assembling electrode structures comprises a horizontal base plate rotatable about a vertical axis and carrying a plurality of pedestals evenly spaced about the axis on each of which a structure can be assembled, the pedestals being mounted on the base plate for limited relative movement in the plane of the plate, a horizontal aligning plate having a plurality of aligning means positioned so that on relative vertical movement of the base plate and aligning plate the pedestals are aligned accurately relative to associated guide means for feeding the components one at a time to the pedestals, each guide means being fed with a different component, means for producing relative vertical movement between the base plate and aligning plate and means for rotating the base plate in steps to align each pedestal with each guide means in turn. The pedestals 4, Fig. 2, are mounted on a rotatable plate 1 by means of screws 21 in overlarge holes 22 so as to be capable of slight movement in the plane of the plate, and comprises a steel base 23 having an extension 24 of epoxy resin in which is a metal insert 25 having locating pips 8. A plate 2 having a plurality of funnel-shaped apertures 5 corresponding to the number of pedestals is mounted above the plate 1 and can be raised or lowered to effect the alignment by means of an air cylinder. The plate 2 carries a succession of guides 9 appropriately shaped to deliver the various components e.g. grids, screens and anodes. As shown it has a central funnel 10 for delivering a cathode 12. A mica disc 7 is first supplied to the pedestal 23 and located by the pips 8. The pedestal is then indexed to the next position and there receives the cathode 12 which is secured to the disc 7 by downward pressure from a spring plunger 6 on a third plate 3 which is raised and lowered at appropriate intervals by a second air cylinder. The pedestal is then indexed to the next position and a further component similarly applied. In a modification, the plate carrying the pedestals is moved up and down, the aligning plate being stationary. In this form, the different components may be fed to successive indexing positions by chain magazines 46, Fig. 6. The chain consists of a series of solid links 47 passing round idle or driving sprockets 48, 49 and supported by a platform 50. The sprocket 49 is driven in synchronism with the indexing of the plate carrying the pedestals by a ratchet and toothed wheel mechanism driven by an air cylinder. The links have holes 54, 55 shaped to receive the components, the holes registering in turn with guides 59, 60 leading to funnel-shaped openings 45 in a fixed plate 33. The plate carrying the pedestals is indexed to present the pedestals in succession below the openings 45 and is then moved up to cause the pedestals to enter the openings, a plunger mechanism 57, 58 then operating to push the components from the holes 54, 55 through the guides 59, 60 into place on the pedestals. The pedestal carrying plate then moves downwards and is indexed one step forward and the cycle is repeated. A top mica disc is finally applied.