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A valve for sealing a conduit under pressure has an armature (12) cooperating with two springs, a permanent magnet, and a solenoid coil. The force of the permanent magnet is used to cock a spring and thereby stored primarily as a spring force when the valve is in any of its two end positions. THe sp

A valve for sealing a conduit under pressure has an armature (12) cooperating with two springs, a permanent magnet, and a solenoid coil. The force of the permanent magnet is used to cock a spring and thereby stored primarily as a spring force when the valve is in any of its two end positions. THe spring force is slightly smaller than the permanent magnetic force of the permanent magnet, and this slightly smaller spring force is effective on a valve stem through a sleeve in a direction opposite to that of the permanent magnetic force. The permanent magnetic force is, for example, stored in a Belleville spring and additionally in a helical or conical spring which provides an extra valve biasing force. In order to open the valve, the solenoid coil (9) of an electromagnet is energized to counteract the force of the permanent magnet to an extent slightly below the stored spring force. Thus, this valve is capable of having a monostable or a bistable characteristic, depending on the adjustment of the spring force with the aid of an adjustment ring engaging a threading on the valve stem.

대표청구항 ▼

A valve for sealing a pressurized conduit, comprising: (a) a valve housing including a housing cover, a permanent magnet having a permanent magnetic force in said valve housing, an electromagnet generating an electromagnetic force for operating said valve, said electromagnet including a solenoid coi

A valve for sealing a pressurized conduit, comprising: (a) a valve housing including a housing cover, a permanent magnet having a permanent magnetic force in said valve housing, an electromagnet generating an electromagnetic force for operating said valve, said electromagnet including a solenoid coil and an armature in said housing, said permanent magnetic force normally pressing said armature against said housing when said valve is closed, and spring means arranged for cooperation with said solenoid coil when said solenoid coil is energized, (b) said permanent magnet being arranged in a recess in a lower portion of said solenoid coil facing said armature, a housing extension reaching radially inwardly, said solenoid coil and said permanent magnet each having a downwardly facing side having direct contact with said housing extension, a magnetizable soft iron ring arranged between said solenoid coil and said permanent magnet, so that, when said valve is closed, a magnetic circuit of said permanent magnet establishes itself between a north pole and a south pole of said permanent magnet through said soft iron ring and through said housing extension substantially without an air gap, (c) sleeve means for closing and opening said valve operable by said permanent magnet through said armature, said spring means comprising a first spring having a first spring force and a second spring having a second spring force, said first and second springs being arranged for cooperation with said sleeve means, so that when said valve is closed said permanent magnetic force of said permanent magnet urges said first and second springs in a valve closing direction, whereby a larger proportion of said permanent magnetic force is effective on said first spring than on said second spring, (d) wherein during opening of said valve said electromagnetic force initially overcomes said second spring force through a gap (29) formed between said armature and an adjustment ring, whereupon said electromagnetic force reduces the effect of said permanent magnetic force down to zero, whereby energy stored in said first spring becomes free for fully opening said valve, and wherein (e) an air gap (G) is formed between a downwardly facing surface of said armature and said housing extension when said valve is fully opened, so that said permanent magnetic force which is effective on said armature through an outer magnetic circuit in a valve opening direction, is also effective for biasing said first spring to store energy in said first spring when said valve is fully opened.