VACUUM TUBE INSERT ASSEMBLY WITH FEED-THROUGH PIN PLUG AND MATING SOCKET
A vacuum tube insert assembly includes a flared insert piece having an annular flange and a stem each constructed of glass. The stem extends axially from the flange. The flange surrounds a perimeter edge of a plug concavity defined by the stem. Feed-through pins pass axially through the stem and are sealed thereto. The pins terminate inside of the concavity to form a plug. A socket connects to the plug within the concavity and includes receptacles that removably couple to the pins, with an engagement feature preventing erroneous plug and socket connections. A method includes axially inserting the pins through the stem at a fixed relative position such that the pins are arranged within the plug concavity, sealing the stem such that the stem is vacuum-sealed to the pins, thereby forming the plug, and removably coupling mating receptacles of the socket to the pins.
1 . A vacuum tube insert assembly comprising:
a flared insert piece comprising an annular flange and a stem extending axially from the annular flange, the flared insert piece defining a plug concavity; and
a feed-through pin comprising a continuous material extending a first distance from an internal surface of the stem into an internal volume of the vacuum tube insert assembly, through the stem, and extending a second distance from an external surface of the stem into the plug concavity.
2 . The vacuum tube insert assembly of claim 1 , further comprising a center post extending through the stem, wherein at least one of the center post or the feed-through pin comprises a keyed or splined surface.
3 . The vacuum tube insert assembly of claim 1 , further comprising a center post extending through the stem, wherein a first diameter of the center post is greater than a second diameter of the feed-through pin.
4 . The vacuum tube insert assembly of claim 3 , further comprising a cathode assembly electrically coupled to the feed-through pin and the center post.
5 . The vacuum tube insert assembly of claim 1 , wherein:
the feed-through pin is a first feed-through pin;
the vacuum tube insert assembly further comprises a second feed-through pin extending through the stem;
the second feed-through pin extends a third distance from the external surface of the stem into the plug concavity; and
the third distance is different from the second distance.
6 . The vacuum tube insert assembly of claim 1 , wherein the feed-through pin is sealed to the stem.
7 . The vacuum tube insert assembly of claim 1 , wherein:
the flared insert piece comprises borosilicate glass; and
the feed-through pin comprises at least one of tungsten, molybdenum, or a nickel cobalt alloy.
8 . The vacuum tube insert assembly of claim 1 , wherein the feed-through pin comprises a first metal plated with a second metal.
9 . A method of forming a socket for a vacuum tube insert assembly, the method comprising:
inserting a center post through a stem of a flared insert piece into a pin fixture to index the flared insert piece with the pin fixture;
inserting a feed-through pin through the stem into the pin fixture; and
sealing the stem to the center post and the feed-through pin.
10 . The method of claim 9 , further comprising electrically connecting a cathode assembly to a free end of the feed-through pin.
11 . The method of claim 9 , further comprising inserting a fixture post of the pin fixture into a plug concavity defined in the stem.
12 . The method of claim 9 , further comprising contacting an annular flange of the flared insert piece against a planar base of the pin fixture, the annular flange encircling the stem of the flared insert piece.
13 . The method of claim 9 , wherein:
the feed-through pin is a first feed-through pin;
the method further comprises inserting a second feed-through pin through the stem into the pin fixture; and
the first feed-through pin and the second feed-through pin extend different distances into the pin fixture.
14 . The method of claim 9 , wherein the center post and the feed-through pin are inserted into mating openings of the pin fixture, the pin fixture having a fixed spacing between the mating openings.
15 . The method of claim 9 , wherein the feed-through pin is inserted through the stem such that the feedthrough pin comprises a continuous material extending outward from two opposite surfaces of the stem.
16 . A vacuum tube insert assembly comprising:
a plug comprising:
a stem; and
a center post extending through the stem;
a cathode assembly electrically connected to the center post; and
an envelope sealed to the plug and encapsulating the cathode assembly.
17 . The vacuum tube insert assembly of claim 16 , wherein the cathode assembly is chucked onto the center post.
18 . The vacuum tube insert assembly of claim 16 , wherein the center post comprises a continuous material extending a first distance from an inner surface of the stem into an internal volume defined by the envelope and extending a second distance from an outer surface of the stem to terminate inside of a plug concavity defined by the stem.
19 . The vacuum tube insert assembly of claim 16 , wherein:
the plug further comprises a feed-through pin extending through the stem;
the feed-through pin has a diameter less than a diameter of the center post; and
the cathode assembly is electrically connected to the feed-through pin.
20 . The vacuum tube insert assembly of claim 19 , wherein at least one of the center post or the feed-through pin comprises a mating feature configured such that the plug receives a socket in a unique orientation.