Magnetic sensing proximity detector

Abstract

The improved magnetic proximity detector includes a tubular housing, a tubular magnet fixed in position within the housing, a first movable magnet within the housing at one end of the tubular magnet, a second movable magnet with the housing at the other end of the tubular magnet, an annular magnet positioned in surrounding relationship to the housing and being adjustable axially with respect to the housing, a switch having a blade, a first contact and a second contact, a connection extending between the first and second movable magnets and to the switch blade to move the switch blade responsive to movement of the magnets, the poles of the first movable magnet arranged so that the magnet is attracted to the tubular magnet, the poles of the second movable magnet arranged so that the magnet is repelled by the tubular magnet, the end of the housing containing the first movable magnet moving the two magnets responsive to ferrous metal in close spaced relationship to such end to change the position of the blade switch and the movement of the annular magnet changing the focus of the flux from the end of the housing containing the first magnet to adjust the distance at which the presence of ferrous metal causes the change of position of the switch blade.

Dependencies are inferred from the claim text.