Hydromagnetic control in time delay switch - has blind tube closed at its open end by magnetic disc crimped to radial flange of tube

摘要

The device has a tube of non-magnetic material closed at one end by an integral base and at its other end by a magnetic disc sealed to a radial flange on the tube end by a ring joint, the flange edge being peened over the disc outer edge to grip it against the joint. A magnetic core is slidable in the tube with little play and has a stud (11) on its base to contact the tube base and avoid it being held by capillary action, the tube being filled with liquid such as silicon oil whose viscosity is insensitive to temp. changes. The core has a reduced dia. upper portion coaxial with a return coil spring.