Electronic slide ruler calculator

Claim 1

An electronic slide ruler calculator for indicating a measured distance to a precise fraction of a predetermined scale, said ruler calculator comprising an elongated ruler member having spaced opposite parallel first and second surfaces and a measuring straight edge at the second surface, said measuring edge having a plurality of spaced distance indications marked thereat; a distance marker slidably mounted for free movement along the length of the ruler member on the first surface thereof and having a hair sight extending transversely to the ruler member across the first surface and at the measuring edge for visually indicating a distance on the ruler device, said distance marker having electrically conductive contacts thereon along the hair sight; a plurality of spaced electrical contacts on the first surface of the ruler member in a predetermined pattern whereby a plurality of fractional divisions of each distance indication marked at the measuring edge are provided, the distance marker being spring mounted on the ruler member in a manner whereby the contacts of the marker and those of the ruler member directly thereunder make electrical contact when said marker is manually depressed; and calculator circuit means electrically connected to the contacts on the ruler member for indicating the exact position of the distance marker when said marker is manually moved into position and manually depressed so that the contacts of said marker make electrical contact with contacts of said ruler member directly thereunder.