Abstract: All electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and outlet, respectively, an electromagnet carried by the housing external to the fluid chambers thereof, and an armature movable in the housing having a pole portion magnetically attracted by the electromagnet and a piston portion to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston portion between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature. Fluid inertial effect is reduced by an outlet orifice provided in the fluid path from the pump outlet and by a bypass orifice in the fluid bypass path, the outlet and bypass orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system of which the pump is a part.

Abstract: All electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and outlet, respectively, an electromagnet carried by the housing external to the fluid chambers thereof, and an armature movable in the housing having a pole portion magnetically attracted by the electromagnet and a piston portion to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston portion between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature. Fluid inertial effect is reduced by an outlet orifice provided in the fluid path from the pump outlet and by a bypass orifice in the fluid bypass path, the outlet and bypass orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system of which the pump is a part.

Abstract: An electromagnetic pump having an electromagnet carried by the housing external to the fluid chambers, and an armature moveable in the housing having a pole magnetically attracted by the electromagnet and a piston to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature. Fluid inertia is reduced by an outlet orifice in the path of fluid flow from the pump outlet and by a bypass orifice for fluid flow in the bypass path, the orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system including the pump. An accumulator in the fluid flow path between the pump outlet and a catheter leading away from the pump alleviates inertial and viscous effects arising from the catheter.

Abstract: An electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and outlet, respectively, an electromagnet carried by the housing external to the fluid chambers thereof, and an armature movable in the housing having a pole portion magnetically attracted by the electromagnet and a piston portion to force fluid out of the chambers and through the pump outlet. A path provides controlled bypass for bubbles in the fluid around the armature piston portion between the fluid pumping chamber and the fluid receiving chamber only during the return stroke of the armature.Fluid inertia is reduced by an outlet orifice in the path of fluid flow from the pump outlet and by a bypass orifice for fluid flow in the bypass path, the orifices being provided either individually or in combination depending upon the fluid flow characteristics of the system including the pump.