The invention relates to an electromagnetic double-valve having two valves which are electrically controllable in synchronism with each other for controlling the flow of two materials.
Such double-valves are used, for example, in the positioning control system of satellites for the closed loop position control of such satellites. The double-valve has, in a common housing, two valve members which are synchronously electrically controllable. Each of the two valves serves to control the flow of one of the two materials. On the outlet side the two valves may be connected to each other, the outlet conduits for example, are joined and lead into a reaction chamber of a positioning drive mechanism of the satellite. In each of the two valves of the double-valve, an armature serves as the valve body or moving valve plug held in a defined valve position, for example in the closed position of the valve, by means of a magnet. Electromagnets are provided for both valves to transport the armature or valve plug into the other defined valve position, in this case the open position. These electromagnets are actuated by a control current.
The synchronous function of the two individual valves is essential for the satisfactory and acceptable function of such a double-valve. In the described example embodiment of a double-valve for controlling a satellite positioning drive mechanism, this means that both valves must be opened simultaneously and also closed simultaneously. This requirement has been typically achieved heretofore by mechanically linking the two valve bodies of the individual valves. However, such a solution is costly. The lack of such a mechanical linkage causes a considerable deviation from the desired simultaneous switching of both valves for opening and closing because of the differing mechanical and physical parameters within the individual valves. In those instances which depend upon a highly accurate synchronous function, these valves do not satisfy the desired requirements.