US 1942824 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Jan. 9, 1934. A, E McLEOD 1,942,824
ELECTRIC DISCHARGE DEVICE Filed April 14. 1932 Fzg. 4. 7
\ 8' Fig.5. 7
AVTOF/VE/ Patented Jan. 9, 1934 'uNiTEo STATES ELECTRIC DISCHARGE DEVICE Albert Edward McLeod, Kenton, England, as-
signor to The M-O Valve Company Limited,
London, England Application April 14', 1932, Serial No. 605,140, and in Great Britain May 29, 1931 6 Claims.
This invention relates to methods of supporting wires, such as electrode supporting wires, in electric discharge devices.
I "In the manufacture of electric discharge devices a rigid and yet insulating connection has often to be made between wires. A common way of making such a connection is to embed the wires in a bead of glass or similar material. The
object of this invention is to provide an improved l0 substitute for such beads.
In an insulating support for wires in electric discharge devices, according to the present invention, the wires are rigidly held correctly spaced by a metal member which is pressed on to the wires with a strip of thin flexible insulating material interposed between the wires and the member so that the member and strip are deformed by the wires. Preferably the thin flexible insulating material is mica and the metal memher is made of steel.
A metal member and a strip of thin flexible insulating material may be arranged on each side of the wires and the two members may be pressed together to press the wires into both members, furthermore the two members may comprise parts of a continuous metal strip or plate.
The insulating support may conveniently be used for supporting the electrode supporting wires of an electric discharge device.
The invention will now be described by way of example, with reference to the accompanying drawing.
Figure 1 is a side elevation of a broadcast receiving valve showing the insulating support applied to the spacing apart and supporting of the internal electrode supporting wires. Figures 2 and 3 are a plan and side elevation respectively of the support on an enlarged scale. Figures 4, 5, 6 and 7 show various stages in one method of manufacturing the support shown in the previous figures. Figure 8 is a plan of a bottom die which may be used in forming the support and Figure 9 is a section on the line 99 of Figure 8, the corresponding top die being shown in position above the bottom die. Figures 10 and I1 show a modified construction.
With reference to Figure 1 the valve has an envelope which comprises a glass portion 1 and a copper portion 2, the latter portion forming the anode of the valve. The internal electrodes are arranged within the anode 2 and are mounted on electrode supporting wires 3 held suitably spaced apart by an insulating support 4. The internal electrodes and supporting wires are assembled as a single unit before insertion into the are clamped, a strip of mica 8 being interposed between each member 7 and-the wires 3. The two members '7 form parts of a single metal strip in the construction shown, but in some constructions two separate members may be used.
Onemethodof constructing the support may be followed from Figures 4, 5, 6 and '7. The strip '7 is originally in the form of an annulus, Figure 4 being a plan view of such annulus and '75 Figure 5 a side elevation. The annulus is deformed, preferably by inserting a suitably shaped mandrel and applying external pressure, to" form an elongated sleeve as shown in plan view in Figure 6. The two mica strips 8 are placed within the sleeve 7 and the five ele'ctrode'supporting wires 3 are inserted into the sleeve between the strips 8 as shown in Figure 7; preferably atthis stage the electrodes'have been attached to the wires 3. The annulus 7 may be formed by cut- '85 ting a section from a steel tube, or by'bending a strip round in a circle and joining the two ends, for example by welding. In the latter case however the sleeve shown in Figure 6 may be formed direct. The wires 3 are now suitably spaced apart within the sleeve '7 and the sleeve is pressed between two dies so that the wires are pressed into the opposite sides'of the sleeve '7 which are deformed by the wires, at the same time the wires 3 are insulated from one another and from the sleeve 7 by the mica strips 8, which are also deformed by the wires.
Two dies suitable for performing this last operation are shown in Figures 8 and 9 and these, will now be described. The bottom die comprises a solid block of metal in which are formed a small channel 10, in which the top die 11 is adapted to fit, and a larger cross channel 12, which is adapted to receive the wires 3. At each end of 5 the channel 12 are provided two combs the teeth 13 of which serve to space the wires 3 the correct distance apart. The part of the bottom die which is common to the two channels 10 and 12 is formed with five troughs 14 corresponding to the fivewires 3. The top die 11 is similarly formed with five troughs 15.
When the wires 3 have been inserted in the sleeve 7 between the mica strips 8, the sleeve 7 is arranged in the channel 10 of the bottom die so that the projecting wires 3 extend along the channel 12 and are spaced apart correctly by the teeth 13, a tooth 13 being arranged between each pair of adjacent wires. The top die 11 is now lowered into position in the channel 10 and the two dies pressed firmly together. The result is that the sides of the sleeve are pressed onto the wires 3, which thereby deform the sleeve by being pressed into it and forcing parts of the sleeve into the troughs 14 and 15, and a support as shown in Figures 2 and 3 is formed.
In the modified construction shown in Figures 10 and 11 a long rectangular hole 18 is formed in a flat rectangular metal plate as shown in Figure 10. The plate is then folded about the line 17 to the form shown in Figure 11, which is a section on the line 16i6 of Figure 10 of the plate after it has been folded, so that the parts of the plate on the two sides of the line 17 are arranged opposite one another and constitute the two members 7. The wires 3 are now passed through the hole 18, suitably spaced apart with the mica strips 8 arranged on opposite sides of the wires as shown and the two members 7 are pressed together against the wires 3 between two dies as in the previous construction. Instead of forming a single hole 18 to take all the wires 3 separate holes may be formed to take one or more of the wires.
If desired the support may be formed from two separate members 7 held together in any suitable manner, for example by bending the end of one member over the end of the other at the same time as the members are pressed together. Alternatively the two members may form the two arms of a U shaped member, which arms may be pressed together to grip the wires 3.
Although mild steel has been mentioned as a suitable metal to use for the members there are many others which may be used, for example copper-nickel alloys, copper, or nickel.
1. In the manufacture of an electric discharge device a method of forming an insulating sup port for rigidly holding wires correctly spaced apart which comprises arranging two strips of thin flexible insulating material and the spaced wires within an elongated metal sleeve, the wires being arranged between the two strips, and applying pressure to the two opposite sides of the metal sleeve so as to deform the latter and press the strips against the Wires whereby the Wires are held in proper spaced relation.
2. In the manufacture of an electric discharge device themethod of forming an insulating support for rigidly holding wires correctly spaced apart which comprises arranging a strip of metal around the spaced wires, arranging strips of mica to insulate the wires from the metal strip and then applying pressure to the metal strip so as to force the mica against the wires and deform the metal strip and the mica strips so as to hold the wires in proper spaced relation.
3. In the manufacture of an electric discharge device a method of forming an insulating support for rigidly holding wires correctly spaced apart which comprises arranging the wires in spaced relation with a metal member within a mold, placing thin flexible insulating material between the spaced wires and the metal member, then applying pressure to the metal member to deform both the insulating strip and the metal member over the wires and form grooves into which the wires are forced.
4. In the manufacture of an electric discharge device a method of forming an insulating support for rigidly holding wires correctly spaced apart which comprises arranging a metal member with opposed portions on opposite sides of the Wires and placing thin flexible insulating material on each side of the spaced wires between said opposed portion of said member and the wires and then applying pressure to the opposed portions of the metal member so as to force the insulating material and the opposed portions of said metal member inward to permanently deform the metal member around the wires and corrugate the insulating strips to thereby secure the wires in properly spaced relation.
5. In the manufacture of an electric discharge device a method of forming an insulating support for rigidly holding wires correctly spaced apart which comprises folding a metal plate formed with a hole about a fold-line passing through the hole, arranging the wires between two strips of thin flexible insulating material, inserting the wires and the strips of insulating material between the oppositely disposed parts of the plate on the two sides of the fold-line so that at least one of the wires passes through the hole in the plate, and then applying pressure to said oppositely disposed parts so as to force them together and press the strips against the Wires.
6. An electric discharge device comprising a plurality of electrode supporting wires arranged in a row, strips of thin flexible non-adhesive insulating material arranged on opposite sides of the row of wires, the strips being corrugated to form opposite grooves into which the wires fit and a single metal member with opposed portions similarly corrugated and arranged to closely embrace the insulating strips on opposite sides of the wires so as to resiliently hold the wires firmly in the grooves, correctly spaced apart and properly insulated. I
ALBERT EDWARD McLEOD.