Karnavas Transistor Base Assembler
date: label: Date made
content: 1952
name: label: maker
content: Texas Instruments
notes: label: Description (Brief)
content: Equipment invented by donor at TI to fabricate the base for a germanium point-contact transistor and setting the spacing of the contacts using a five-station assembly process. See US Patent #2962058, "Apparatus for forming point contacts for transistors," issued 29 November 1960 to Esidoros C. Karnavas (1922-2011), Boyd Cornelison (1915-2001), and Helmut Braun. Patent filed 6 July 1953. This apparatus uses a pre-assembled base of two notched lead-wires set in an insulating disc, and two spools of contact wire (not included). The patent describes the 5-stage process as follows: Stage 1 - contact wires are set in the lead-wire notches and peaned into place; Stage 2 - the contact wires are cut (separating the bases from one another); Stage 3 - the contact wires are trimmed to exact length and bent into position; Stage 4 - the spacing between the contact wires is precisely set (the exact spacing depends on the intended use of the transistor and can be varied by the device operator as needed); Stage 5 - a bend is formed in one lead wire to mark the polarity of the transistor. There are also 2 spring-loaded pins attached to the base that do not appear in the patent.
label: Description (Brief)
content: Note: when comparing the object to the patent drawing and descriptions, stages 3 and 4 are reversed on the object. The device in position number 4 is actually stage 3 (figures 11, 12, 13 in the patent), and the device in position 3 is actually stage 4 (figures 14, 15 in the patent). There is a trough milled in the base at position 4 that allows cam #116 of stage 3 to rotate (see figure 13) - stage 3 is the only stage that requires such a trough so the reversal of stages 3 and 4 on the apparatus was not simply someone accidentally misplacing these pieces. The base was milled to accept stage 3 in position 4 and without that milled trough at position 3, the stage 3 device on this object will not fit in its proper location.
label: Description (Brief)
content: The patent (in the last paragraph before the claims) states "There are many forms in which this invention can be practiced. Instead of being used as a continuous process through all five stages as disclosed, fabrication can proceed independently through one stage at a time. Or, instead of power-driven means, hand operated cranks can be used. The invention is not intended to be limited to the exact form disclosed, but any means by which the same functions can be accomplished and that would occur to anyone skilled in the art, are within the scope and spirit of this invention."
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Electricity
creditLine: label: Credit Line
content: from Esidoros C. Karnavas
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1988.0473.01
label: accession number
content: 1988.0473
label: catalog number
content: 1988.0473.01
objectType: label: Object Name
content: transistor assembly apparatus
physicalDescription: label: Measurements
content: overall: 10.5 cm x 81.2 cm x 10.1 cm; 4 1/8 in x 31 15/16 in x 4 in
label: Measurements
content: disks: 3.8 cm; x 1 1/2 in