Four-contact magnetic switch apparatus

A switch assembly comprising:

• a switch unit having—
• a housing having walls presenting electrically conductive zones;
• first and second, spaced apart, electrically conductive contacts within said housing and respectively adjacent corresponding first and second electrically conductive housing wall zones;
• a shiftable, electrically conductive body within said housing and magnetically movable between a first switch state where the body is in simultaneous contact with said first contact and a first housing wall zone, and a second switch position wherein the body is in contact with said second contact and a second housing wall zone;
• a biasing element proximal to said housing,
• said biasing element and body being magnetically correlated such that said biasing element magnetically urges said body towards one of said switch states,
• said body being magnetically shiftable under the influence of a magnetic field acted upon said body against the magnetic correlation between said body and said biasing element, in order to move said body to said second switch position;
• a third electrically conductive contact within said housing, located between said first and second contacts, and adjacent a corresponding third conductive housing wall zone,
• said body shiftable within said housing to a third switch state where said body is in simultaneous contact with said third contact and said third conductive housing wall zone, under the influence of an external defeat magnet placed proximal to said housing.

A switch unit comprising:

• a housing having walls presenting electrically conductive zones and a cavity;
• first and second, spaced part, electrically conductive contacts within said housing and respectively adjacent corresponding first and second electrically conductive housing wall zones, said first and second contacts lying on a common axis;
• a third electrically conductive contact within said housing located between said first and second contacts and spaced from said common axis;
• a shiftable, electrically conductive body within said housing cavity and movable between a first switch state where the body is in simultaneous contact with said first contact and a first housing wall zone, a second switch state wherein the body is in contact with said second contact and a second housing wall zone, and a third switch state wherein the body is in contact with said third contact and a third housing wall zone,
• said first, second, and third contacts being adapted for connection with a controller.