Jack's Patent 3,313,057

Jack patented some color code caps for knobs for electronic gear on April 11, 1967.  The application was made on Oct. 26, 1964.  I remember the knobs well.  We often played with these electronic knobs that were always around Jack's workroom.  The machines that were used to produce the knobs would extrude globs of plastic that we all thought really cool-looking and collected in the family garden for a while.  You can see the patent by clicking on this link:  3,313,057