GB1438774A - Cathode-ray-tube yoke combination - Google Patents

Abstract

1438774 Cathode ray tubes RCA CORPORATION 16 Aug 1973 [21 Aug 1972] 38706/73 Heading H1D A c.r.t. (e.g. colour) and deflection yoke are rigidly joined by at least two paced solid bodies 30 of adhesive organic thermoplastic material bonded directly between the yoke windings and the tube, the bodies filling <20 vol per cent of the space between the yoke and tube. The yoke may be toroidal or saddle type (Figs. 4, 5, not shown) with three adhesive strips (Figs. 2, 3) or four (Figs. 4, 5). Temperatures and yoke and tube dimensions are detailed. In Fig. 5, groups (47) are connected in pairs at front and rear and preferably each strip (40) is centred on the four groups (47) to provide uniform movement to compensate temperature variations. The strips may be cast between six silicone foam rubber strips (49) on the inside or outside of yoke and tube respectively, the combination then operatively assembled, and where no dynamic convergence circuitry is used, may be finally adjusted while the tube is operated, the liquid thermoplastic injected, the tube and yoke being maintained at <50‹ C. or forced cooled. The first injected material may harden at the opposite end from the injection and no means provided to restrict flow beyond the yoke end. Small rubber tubing of neoprene rubber, butyl rubber or polyethylene may also be used. Strips (49) may be removed or retained, adhesive backed polyurethane foam tape being used if retained. Strips 30, (40) may be segmented or staggered, also ¢ inch diameter bodies may be used (e.g. three, peripherally spaced each end), The structure allows air circulation and cooling. Yoke 29 may include an auxiliary electromagnet or permanent magnet for convergence or purity.