Abstract The pilot-operated diaphragm valve is controlled by a solenoidactuated plunger guided in a plastic tube having a very thin wall to minimize the loss of magnetic coupling while providing freedom from corrosion and electrolysis with reduced wear and substantial reduction or elimination of vibration buzz or hum. The plastic guide is supported throughout its thin wall length by upper and lower flux sleeves of magnetic material separated by a nonmagnetic material which in this case is a portion of the plastic coil bobbin but can alternatively be any nonmagnetic material. The extended lip on the plastic tube helps seal the diaphragm and prevents extrusion of the diaphragm under high pressure. The flat valve face seating on the rigid valve seat insert in the diaphragm alleviates centering problems and allows increased clearance between the plunger and tube.
A solenoid valve comprising a magnetic frame, a coil mounted in the frame, magnetic flux sleeves extending from the frame into the coil from opposite ends of the coil, a nonmagnetic spacer sleeve between the facing ends of the flux sleeves, the inside diameters of the sleeves being substantially the same, a nonmagnetic thin-walled plastic tube inside the sleeves and radially supported by the sleeves when subjected to pressure, the upper end of the tube being closed and thickened to be selfsupporting under pressure, a magnetic valve-plunger in the plastic tube to be magnetically coupled by the flux between the flux sleeves, said valve being mounted on a body and including a diaphragm, the lower end of the lower flux sleeve and the lower end of the tube both being belled to accommodate flexure of the diaphragm, both the diaphragm and the belled end of the tube being seated in an annular groove in the body and held therein by the belled lower sleeve.
Claim 2
Dependent Claim
164 words
A solenoid valve comprising a magnetic frame, a coil mounted in the frame, magnetic flux sleeves extending from the frame into the coil from opposite ends of the coil, a nonmagnetic spacer sleeve between the facing ends of the flux sleeves, the inside diameters of the sleeves being substantially the same, a nonmagnetic thin-walled plastic tube inside the sleeves and radially supported by the sleeves when subjected to pressure, the upper end of the tube being closed and thickened to be selfsupporting under pressure, a magnetic valve-plunger in the plastic tube to be magnetically coupled by the flux between the flux sleeves, said valve being mounted on a body and including a diaphragm, the lower end of the lower flux sleeve and the lower end of the tube both being belled to accommodate flexure of the diaphragm, both the diaphragm and the belled end of the tube being seated in an annular groove in the body and held therein by the belled lower sleeve.