Electromagnetic pumps

In an electromagnetic pump of the type comprising a nonmagnetic sleeve, a plunger slidably contained in the sleeve, inlet valve means and outlet valve means coupled to said plunger, an inlet fixture and an outlet fixture disposed on the opposite ends of said sleeve, an exciting coil surrounding a portion of said sleeve between said inlet and outlet fixtures, means for passing pulsating current through said exciting coil for reciprocating said plunger, and a return spring acting on said plunger thereby pumping liquid by the reciprocating motion of said plunger in cooperation with said inlet valve means and said outlet valve means, the improvment which comprises a generally U shaped yoke member made up of a pair of spaced parallel legs and a connecting plate for interconnecting one end of said pair of legs, a generally U shaped housing member combined with said yoke member so as to define a closed space adapted to substantially contain said exciting coil, said means for passing pulsating current, said plunger and said sleeve, and means for fastening together said combined yoke member and said housing member, said pair of legs being provided with openings for securing said inlet fixture and said outlet fixture respectively, said legs being further provided with notches, said pump further comprising a printed substrate carrying electronic elements including a transistor which constitute an oscillator for supplying pulsating current to said exciting coil, said printed substrate being received in said notches of said legs, and wherein said housing member is provided with a plurality of projections engaging said notches of said legs for securing said housing member to said yoke member.