Wilson Greatbatch Ltd.

Greatbatch Enterprises, Inc.

Lawrence E Morris

Theodore J Falk

W Richard Brown

Norbert W Frenz, Jr

Raymond S Konopa

Douglas K Gillies

Norbert W Franz, Jr

Low power electromagnetic pump

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. The armature pole has a fluid-contacting section of material which is compatible with and corrosion resistant to the fluid, which can be a body of magnetic material within a titanium enclosure or a body of chrome-molybdenum-iron alloy.

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. 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. The armature pole portion has a fluid-contacting section of material which is compatible with and corrosion resistant to the fluid, which can be a body of magnetic material within a titanium enclosure or a body of chrome-molybdenum-iron alloy. The check valve and inlet are so arranged that the pump displacement can be reduced without reducing the bubble pumping capability of the pump.

An electromagnetic valve comprising a housing having a fluid containing region and first and second ports in communication with the region, an electromagnet carried by the housing located external to the fluid containing region, and a thin diaphragm of fluid impermeable material which hermetically isolates the electromagnet from the fluid containing region. An armature is movably positioned in the region and has a pole portion located for magnetic attraction by the electromagnet and has a plunger portion provided with a valve formation for opening and closing one of the ports to place both ports in fluid communication through the fluid containing region of the housing and to block fluid communication between the ports. The armature is moved from a rest position through a forward stroke when attracted by the electromagnet to change the control state of the valve, and the armature is moved by a biasing spring in an opposite direction through a return stroke back to the rest position. The armature pole portion is of a material selected to achieve a desirable balance between fluid compatibility and magnetic properties for rapid and effective valve operation. Passages in the barrier and the armature pole portion allow the rapid valve movement and accommodate bubbles in the fluid, the armature is provided with structure for effectively guiding the same, and a valve seat structure resists fluid leaks.

Low power electromagnetic valve

An electromagnetic valve comprising a housing having fluid containing region and first and second ports in communication therewith, an electromagnet carried by the housing located external to the region, and a thin fluid impermeable diaphragm barrier hermetically isolating the electromagnet from the region. An armature in the housing is movable within a body of magnetically permeable material and has a pole portion located for magnetic attraction by the electromagnet and has a valve portion located for opening and closing one of the ports to place the ports in fluid communication through the region in one state of the valve and to block fluid communication between the ports in another state of the valve. The armature is moved from a rest position through a forward stroke when attracted by the electromagnet and is returned by a biasing spring to the rest position. A magnetic circuit includes the electromagnet, a portion of the barrier, the body, the armature pole portion and a gap between the pole portion and the electromagnet located in the fluid containing region of the housing which gap is closed during forward movement of the armature. The valve is made electrically and magnetically efficient by minimizing the total gap within the magnetic circuit, by having the armature pole face area relatively large, and by having the electromagnet coil or core of relatively small diameter.

An electromagnetic pump comprising a housing having a fluid receiving chamber in communication with an inlet, a pair of fluid chambers connected by a fluid bypass passage to accommodate bubbles, one in communication with the fluid receiving chamber and the other in communication with an outlet, an electromagnet carried by the housing located external to the fluid chambers thereof, and a barrier in the form of a thin diaphragm of fluid impermeable material which hermetically isolates the electromagnet from the fluid chambers. An armature in the housing is movable within a body of magnetically permeable material which contains the bypass, has a pole portion located for magnetic attraction by the electromagnet, and has a piston portion, preferably of smaller cross-section than the pole portion, for forcing fluid from the fluid chambers and through the outlet. The armature is moved from a rest position through a forward pumping stroke when attracted by the electromagnet and is moved by a biasing spring in an opposite direction through a return stroke back to the rest position. A main valve is movably carried by the armature and located in the fluid receiving chamber for closing the pump inlet when the armature is in the rest position and allowing opening the inlet after the armature begins the forward pumping stroke. The structure and arrangement of the check valve minimizes the volume of the fluid receiving chamber to limit the maximum size of a bubble contained therein. A bypass passage containing a check valve which opens during the armature return stroke provides a path for bubbles around the piston to the fluid receiving chamber.

An electromagnetic pump comprising a housing having fluid receiving and pumping chambers in communication with an inlet and an outlet, respectively, an electromagnet carried by the housing external to the fluid chambers, and a barrier in the form of a thin diaphragm of fluid impermeable material which hermetically isolates the electromagnet from the fluid chamber. An armature in the housing is movable within a body of magnetically permeable material and has a pole portion located for magnetic attraction by the electromagnet and has a plunger portion in the pumping chamber for forcing fluid out of the chamber through the outlet. The armature is moved from a rest position through a forward pumping stroke when attracted by the electromagnet to force fluid out of the pumping chamber through the outlet, and the armature is moved by biasing spring in an opposite direction through a return stroke back to the rest position. The pump is made electrically and magnetically efficient by minimizing the total gap within the magnetic circuit, by having the pole face area relatively large on the armature pole portion, and by having the electromagnet include a coil or a core of relatively small diameter. A pump check valve closes the pump inlet when the armature is in the rest position and opens the inlet after the armature begins the forward pumping stroke.

An electromagnetic pump comprising a housing having a fluid receiving chamber in communication with an inlet, a pair of serially-connected fluid pumping chambers, one in communication with the fluid receiving chamber and the other in communication with an outlet, an electromagnet carried by the housing located external to the fluid chambers thereof, and a barrier in the form of a thin diaphragm of fluid impermeable material which heremetically isolates the electromagnet from the fluid chambers. An armature in the housing is movable within a body of magnetically permeable material, has a pole portion located for magnetic attraction by the electromagnet, and has first and second plunger portions in respective ones of the pumping chambers for forcing fluid out of the chambers and through the outlet. The armature is moved from a rest position through a forward pumping stroke when attracted by the electromagnet to force fluid from one pumping chamber to the other and then out of that chamber through the outlet, and the armature is moved by a biasing spring in an opposite direction through a return stroke back to the rest position. A pump check valve is within the pump and associated with the armature in the form of a valve member located in the fluid receiving chamber, movably carried by the armature, and positioned for closing the pump inlet when the armature is in the rest position and opening the inlet after the armature begins the forward pumping stroke. The arrangement is such that the volume of the fluid receiving chamber is minimized in the region between the check valve and the neighboring one of the armature plunger portions. Long term sealing against back flow is provided by a relatively stronger biasing spring, and short term sealing by a relatively weaker biasing spring.

Growing community of inventors

Bowmansville, NY, United States of America

Lawrence E Morris