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US 4,302,743 AGranted
Solenoid apparatus
AssigneeKabushiki Kaisha Fujikoshi
InventorKazuo Araki
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AssigneeKabushiki Kaisha Fujikoshi
InventorKazuo Araki
Estimating the term…
An improved solenoid apparatus for operating valves such as hydraulic/air valves or other mechanical devices including a pressure proof tube which is wholly or partially nonmagnetic and has one end connected sealingly to a stationary core, an armature slidably mounted in contact with the inner face of the pressure proof tube, and a coil assembly comprising substantially a yoke and a coil encompassing the pressure proof tube. A cylindrical magnetic ring enclosing a part of the stationary core and a part of the pressure proof tube in the vicinity of the end face at the attracting side of the stationary core is inserted between the stationary core and the coil assembly the one end of the magnetic ring protruding axially over to the armature side, whereby the solenoid can be used either with alternating or direct current merely by replacing the coil assembly. When the solenoid is connected to an AC power source, there is no need to install a shading coil and therefore, the apparatus is low in cost and reliably endures impact loads.
A solenoid apparatus adapted for use for hydraulic/air valves or other mechanical devices including a pressure proof tube made from nonmagnetic material, an armature slidably mounted in contact with the inner face of said pressure proof tube, a stationary core secured sealingly to the end portion of said pressure proof tube and having a through opening in the vicinity of the axial center thereof, and a coil assembly including a coil and a yoke surrounding said pressure proof tube and attracting the armature when current flows in said coil, wherein the improvement comprises a cylindrical magnetic ring enclosing a part of said stationary core and a part of said pressure proof tube adjacent the end face at the attracting side of said stationary core, said magnetic ring being fitted fixedly between the stationary core and said coil assembly, an end portion of said magnetic ring adjacent said armature protruding out over the end face at the attracting side of said stationary core toward the armature side thereof.
Dependencies are inferred from the claim text.