Electromagnetic actuator

An electromagnetic actuator comprising:

• (a) a housing made of a magnetic material and having a tubular body;
• (b) a pair of stators made of a magnetic material and disposed at opposite ends of said tubular housing body, each of said pair of stators having a tubular portion, said tubular portions of said pair of stators being disposed coaxially with each other and having their one ends disposed in opposed spaced relation to each other;
• (c) an annular solenoid assembly accommodated within said housing and having opposite end portions in which said tubular portions of said pair of stators are received, said tubular portions of said pair of stators and said solenoid means jointly forming a space, said housing and said pair of stators jointly constituting a magnetic circuit for said solenoid means;
• wherein the solenoid assembly comprises a hollow bobbin of a non-magnetic material and a solenoid mounted around said bobbin, said bobbin having a projection formed on its inner peripheral surface, said projection being interposed between the opposed ends of said tubular portions of said pair of stators in such a manner that the opposite ends of said projection are held against the opposed ends of said tubular portions;
• and
• (d) an armature received within said space and being operable by said solenoid assembly to move along the axis of said tubular portions, wherein said solenoid assembly, when supplied with an exciting electric current, imparts a force to said armature.