Probe for sensing characteristics of electrical devices utilizing a magnetic switch sensor biased by an encircling magnetic biasing means

Claim 1

A probe for sensing magnetic field characteristics generated by electric devices comprising in combination: a non-magnetic housing, a magnetizable switch forming a pair of contactable members mounted within said housing, at least one of said members being movable in said housing relative to the other for engaging the other when in a magnetic field, a lamp, battery means having a pair of terminals, a first means for connecting said lamp and said members in a series arrangement across the terminals of said battery means, said members when exposed to a first magnetic field generated by an electric device deflecting relative to each other to engage to complete a circuit across said battery means to illuminate said lamp, encapsulating means for said probe, said encapsulating means comprising a first part forming a cylindrical configuration encasing said lamp and battery means and a second part forming an elongated constant diameter cylindrical projection of said first part and of a size reduced from said first part and containing said housing, and a magnetic means for mounting on and surrounding at least a part of said projection for producing a second constant magnetic field which passes substantially longitudinally through the axis of said switch to aid in closing said switch, said magnetic means comprises a magnet in the shape of a toroid slidably mounted around and snugly fitting the periphery of said projection for increasing the sensitivity of said probe with the center of said magnet being substantially in longitudinal alignment with said members, said magnet being movable along said projection and over said members to a given position causing engagement of said members and when moved from said position along said projection to another position opening said contacts.