Method of making a coil molded into a magnetic stator

A method of making a solenoid coil assembly comprising a bobbin, a pair of electrical terminals having proximal end portions mounted on said bobbin and distal end portions providing for connection with a separable electrical connector, a length of wire disposed as a solenoid coil on said bobbin and having opposite ends attached with said electrical terminals to electrically place the coil across said terminals, a stator comprising an inner tube disposed on the interior of said bobbin and an outer tube disposed on the exterior of said bobbin, and an encapsulant encapsulating the entirety of said coil and bobbin, including the mounting of said terminals' proximal end portions on said bobbin and the attachment of said wire with said terminals, and joining with said stator so that said bobbin, coil, terminals, and stator form a unitary solenoid coil assembly, said method comprising fabricating said bobbin and terminals as a sub-assembly, placing said sub-assembly and said stator in a mold that has first and second mold parts that coact with said stator, as a third mold part, to define a mold cavity such that said terminals project axially from one end, and then injecting encapsulating material into said mold cavity to fabricate said encapsulant and thereby create the unitary solenoid coil assembly, in which the step of injecting encapsulating material into said mold cavity comprises injecting the encapsulating material into an axial end of the cavity opposite the one end from which the terminals project and creating a depression therein that is depressed relative to immediately proximate axial ends of said inner and outer tubes.

A method of making a solenoid coil assembly comprising a bobbin, a pair of electrical terminals having proximal end portions mounted on said bobbin and distal end portions providing for connection with a separable electrical connector, a length of wire disposed as a solenoid coil on said bobbin and having opposite ends attached with said electrical terminals to electrically place the coil across said terminals, a stator comprising an inner tube disposed on the interior of said bobbin and an outer tube disposed on the exterior of said bobbin, and an encapsulant encapsulating the entirety of said coil and bobbin, including the mounting of said terminals' proximal end portions on said bobbin and the attachment of said wire with said terminals, and joining with said stator so that said bobbin, coil, terminals, and stator form a unitary solenoid coil assembly, said method comprising fabricating said bobbin and terminals as a sub-assembly, placing said sub-assembly and said stator in a mold that has first and second mold parts that coact with said stator, as a third mold part, to define a mold cavity such that said terminals project axially from one end, and then injecting encapsulating material into said mold cavity to fabricate said encapsulant and thereby create the unitary solenoid coil assembly, and in which the step of injecting encapsulating material into said mold cavity comprises injecting the encapsulating material into an axial end of the cavity opposite the one end from which the terminals project.