This invention relates to electromagnetically actuated electrical switches and more particularly to such switches having spring contacts sealed in an enclosing envelope.
Sealed contact switches are well known in the electrical arts and long have found extensive application in electrical systems for performing a wide range of switching functions. These switches typically take the form of a pair of overlapping reed springs of a magnetically responsive and electrically conductive material suspended at their ends by the envelope, usually glass, in which they are sealed. A winding encircling the envelope is energizable to generate a magnetic field for actuating the reed springs to control the electrical circuit in which the switch may be connected. Although sealed reed springs having more than two springs for controlling multiple electrical circuits are known, the switch form most generally available and in widest use incorporates only one pair of springs to control the continuity of a single conducting path. Although the advantages of a switch having a number of spring pairs enclosed in a single envelope would appear obvious from both a cost and a packaging viewpoint, the problems encountered in encapsulating even a single pair of springs have not in the past encouraged the use of such a multi-spring pair construction. Such a construction compounds the problem, for example, of providing a positive glass-to-metal seal where the spring members extend through the envelope. The fabrication of a multi-spring switch is also complicated by the necessity of assuring the proper tensioning of the springs and of maintaining a critical spacing between these members. As a result, it has in the past generally been more convenient simply to provide separate switches to control individual circuit paths such as, for example, the tip and ring circuits of a telephone system.
It is an object of this invention to provide a single sealed spring switch for controlling a plurality of conducting paths without aggravating the problems hitherto encountered in the fabrication of sealed, multi-spring pair devices.
Another object of this invention is to provide a new and novel unitary sealed spring switch construction for simultaneously controlling more than one electrical conducting path.