Patent GB-546586-A (GB)
Title: Electron discharge devices
IPC: H01J21/06
Filed: 1941-08-08
Abstract: 546,586. Electron discharge apparatus. STANDARD TELEPHONES & CABLES, Ltd. Aug. 8, 1941, No. 10080. Convention date, Aug. 24, 1940. [Class 39 (i)] An electron discharge device comprises an enclosing vessel having a moulded dished stem to which are sealed two or more hollow metallic terminals each having inserted in it a channelshaped conductor extending into the stem and bent to extend radially towards its centre, each channel-shaped conductor being connected to the corresponding electrode by a coupling member formed from sheet metal. The high-frequency pentode valve shown comprises an anode 26 carried by connections to a hollow terminal 21 at the top of the envelope and surrounding a grid and cathode assembly, shown in Fig. 8, which is carried by its connections to hollow terminals 25 sealed to extensions on a dishshaped vitreous stem 22 sealed to the base of the envelope. The anode is formed in two U- shaped sections carried by a forked suspension member having a tubular portion secured in the terminal 21 and a pair of channel-section arms 29 which are secured over the lap joints between the two sections and are strengthened by angle braces 30. The grid and cathode assembly comprises upper and lower insulating members 31, 32 spaced by a pair of rods 35, 36 which are retained in slots in the ends of the members by clips 37 which frictionally engage the members. These rods carry the grid 40, the grids 41, 43 being carried by further rods 42, 44 passing through the members 31, 32. The multisection filament cathode 46 is carried at the top by spring-retracted hooks and at the bottom by hooks welded to flat members 50, 51, 52 having tongues extending through slots in the member 32. The tongues of the members 50, 52 are secured below the member 32 to the three upright arms of a yoke member 56, and those of the members 51 to separate angle members 57, 58. The yoke 56 and a brace 59 secured to it are attached to a bent channel conductor 60, and the members 57, 58 to channel conductors 61, 62, these conductors being secured in three of the hollow terminals 25. The terminal associated with the conductor 60 is joined to the mid-point of the transformer winding, the other two being connected to the end points. The ends of the rods 35 carrying the grid 40 are connected below the insulator 32 by a horizontal strip 64 which is secured to upright tongues on a yoke 66 attached to a channel conductor 67 secured in one of the terminals 25, and straps 68, 70 connect the rods carrying these other two grids respectively to channel conductors 69, 71 secured in the remaining terminals. U-form shields 73, 74 are welded to the rods 35, 36 and further held by wire passing through lugs on them and side extensions 33 on the insulator 31. Caps 75 in the shields enclose the projecting ends of the grid-supporting wires. A pair of semi-circular shields 76, 77 is mounted on the lower insulator 32, being welded to the rods 35, 36 and wired to lugs 33 on the insulator. When, in order to obtain high voltage amplification, a wider grid is employed which has to be inserted sideways into the envelope and then turned before securing it, the arms of the supporting yoke member extend only to the top of the anode, where they are provided with lugs to which lugs on the anode are secured.