US2206504A

US2206504A - Electrode support

Info

Publication number: US2206504A
Application number: US276110A
Authority: US
Inventors: Brice W Kinyon
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1939-05-27
Filing date: 1939-05-27
Publication date: 1940-07-02
Anticipated expiration: 1957-07-02

Description

July 2, 1940. B. w. KINYON ELECTRODE SUPPORT Filed May 27, 1938 INVENTOR.

ATTORNEY.

Patented July 2, 1940 UNITED STATES ELECTRODE SUPPORT Brice W. Kinyon, Bloomfield, N. J.,' assignor to Radio Corporation of America, a corporation of Delaware Application May 27, 1939, Serial No. 276,110

3 Claims.

t My invention relates to electrode assemblies for electron discharge devices, particularly to means for supporting indirectly heated cathode sleeves in such assemblies.

6 The sleeve of an indirectly heated cathode is usually held at each end in insulating spacers, the cathode being supported in a central upright position inside other tubular electrodes attached to the spacers. Bosses or beads at the ends of it) the sleeves to prevent their endwise movement increases the cost of the sleeve, complicates the assembly of the electrodes, and frequently binds the sleeves and causes bowing when heated.

The object of my invention is improved support and locking means for tubular cathodes, such as cathodes for electron discharge devices, said supporting means and the cathode being inexpensive to make and assemble in said devices in such a way as to obviate bowing.

My invention is defined with particularity in the appended claims and the preferred embodiment is described in the following specification and shown in the attached drawing in which Figure 1 shows an electron discharge device with a cathode embodyingmy invention and Figures 2 and 3 are detailed perspective and side views of specific cathode locking means constructed according to my invention.

The tube shown in Figure 1 comprises an electrode assembly with sheet spacers l of insulating material, such as mica, engaging the ends of the cathode sleeve 2, which is exteriorly activated and contains an insulated heating element, and also engaging the ends of the side rods of anode 3 and grid 4. The assembly is mounted upon the stem of envelope 5 which may be exhausted, sealed oh? and based in the usual manner.

The cathode 2 may be a sleeve of rolled and seamed sheet metal or a drawn seamless tube,

which is, according to my invention, straight sided and has no bosses or beads characteristic of the usual cathode sleeve. The sleeve is locked at one end in the spacer by a tab, ribbon or strip of metal 6 shown in greater detail in Fig-.

ures

2 and 3, and its other end is preferably free to slide in its spacer to permit longitudinal expansion of the sleeve without bowing or buckling. The tab is bent at one end and formed as by die presses with a semi-circular loop I.

The tab is laid on the side of the sleeve with the tab extending beyond the end of the sleeve and at a point 8 near the loop is attachedas by welding to the side wall of the sleeve. In assembling, the end of the sleeve and the tab are threaded through the hole in the spacer to bring of the electrodes to accurately position the sleeve 10 l and positively lock the sleeve in place before joining the electrode assembly to the press leads. By pulling the outer end of the tab, to press the loop against the upper face of the spacer I, and

then swing or rotate the outer end of the tab 15 while under tension, toward the spacer, the tab may be kinked at the edge of the spacer hole. The set thus given the kinked tab positively locks the sleeve in the spacer against longitudinal movement in either direction. With the end of :0 the strip of metal at the loop butted against the side of the sleeve, the loop 7 presents a particularly firm shoulder and bearing surface for the spacer. If the tab is made from. relatively heavy stock, the formed end of. the tab may of 25 course be shaped with a simple right angle bend. Cathode sleeves round in cross section and about .025" in diameter are preferably secured in place with a metal tab of nickel .002" by .010 and about .40" long. 30

A strip of metal attached to one end of the cathode sleeve and bent upward on either side of its place of attachment with the bent-out por-l tions of the strip bearing against opposite sides of the spacer effectively locks the sleeve in place 5 and is inexpensive to assemble with the sleeve. Cathode sleeves locked according to my invention are free to expand longitudinally and will not bow or buckle when heated. My novel cathode tab eliminates the cost of embossing the 40 sleeve and combines in a simple unitary structure an inexpensive cathode lock and connector.

I claim:

1. An electron discharge device comprising a sheet spacer of insulating material, a tubular 45' cathode extending at one end through a hole in said spacer, means for locking said cathode in said hole comprising a strip of metal attached to said one end of said cathode, the strip being bent outwardly from the cathode at each side 50 of its point of attachment and the bentout portions of the strip bearing against opposite sides of the spacer. v

2. An electron discharge device comprising two spaced parallel insulating spacers, a tubular u cathode supported at its ends in holes in said spacers, and means for locking said cathode against endwise movement in said spacers comprising a strip of metal attached to one end of the cathode, the place of attachment being in the hole of one of the spacers and the strip being bent to overlie the edge of the hole in said one spacer, the other end of the cathode being slidably guided by the other of said spacers.

3. A cathode assembly comprising a tubular metal sleeve exteriorly' activated, a connector and locking tab for said. sleeve comprising a strip of metal lying along the side of said sleeve parallel to the axis of the sleeve, said strip having a loop at one end, the strip adjacent the loop being welded to said sleeve, the welded junction of the strip and the sleeve being near the end of the sleeve.

BRICE W. KINYON.