US2734962A - Switch - Google Patents

Description

United States Patent VIBRATOR Herbert A. Cook, Baltimore, Md. Application June 11, 1951, Serial No. 230,985

4 Claims. c1. zoo-9s This invention relates to electric circuit controllers, and more particularly, to a vibrating contact structure characterized by high contact pressure and minimum requirements for starting voltage.

The prior art is familiar with vibrating interrupter assemblies used in conjunction with suitable transformers for the transformation of relatively low voltage direct currents to alternating current potentials of any desired order of magnitude. Early equipment of this type employed relatively low operating frequencies for the vibrating interrupter, which necessitated the use of relatively large and bulky cooperating transforming equipment. In later years, with the application of polarized vibrators, it has been possible to steadily increase the operating frequencies with corresponding diminution in the net weight of the power supply, because of the resulting decrease in the iron and copper needed in the associated transformer. At the same time, the power requirements demanded of such vibrating interrupter assemblies have also increased. Reasonable contact life under such severe conditions of operation demands relatively high contact pressure and, as previously, reliability of the initiation of operation is still required.

Accordingly, one of the primary objects of the invention is to provide a new and novel vibrating interrupter assembly.

Another object of the invention is to provide a new and novel vibrating interrupter assembly uniting high contact pressure and reliable starting.

Still another object of the invention is to provide a novel magnet assembly for use in polarized vibrators.

A further object of the invention is to provide an improved relationship between the contact driving reed and the actuating magnet assembly in a vibrating interrupter.

Still another object of the invention is to provide a high power vibrator with modest driving coil power.

A further object of the invention is to provide a new and novel vibrator in which driving action is relatively unaffected by changes in load.

Other objects and advantages of the invention will in part be discussed and in part be obvious when the following specification is read in conjunction with the drawings in which:

Figure l is a side view of a vibrator embodying the principles of the invention illustrating in detail the relationship of the parts,

Figure 2 is a side view taken at right angles to the view of Figure 1 of the vibrator assembly,

Figure 3 is a view in perspective of the polarizing magnet and,

Figure 4 illustrates schematically a representative circuit employing the vibrator of the invention.

Referring now to Figures 1 and 2, the vibrator mechanism is seen to be assembled between the side plates and 12 secured at the top by tie bolts 14, 15 and at the bottom by similar tying members 16 and 17. A permanent magnet 18 of any suitable alloy is provided with pole piece assemblies 20 and 21 which may be secured to it by clamping bands 22. The entire assembly is then secured between the upper arms of the side plates by taking up on tie bolts 14 and 15.

An insulation stack, indicated at 25, is secured between the lower ends of the side plates 10, 12 by tension in the tie screws 16 and 17. The insulation stack 25 serves to secure the side arms 26 and 28, each of which is provided with a contact at its upper end and apertured to receive a connecting conductor at its lower end. In addition, a spring hinge is clamped in position by the insulation stack 25 and supports a paramagnetic armature 30 whose free end projects into cutout portions of the pole pieces 20, 21. These pole pieces, it will be noted, are disposed in opposing relationship with essentially planar faces sloping away from each other with an included angle which may be approximately twenty degrees. The edges of the pole faces are cut away or rebated adjacent the narrower portion of the air gap and the free tip of the vibrating armature 30 projects within the rebate. The usual bolster plates secure contacts to either side of the vibrating reed and armature assembly, which contacts cooperate with the corresponding contacts on the side arms 26, 28.

In addition to the side arms 26, 28, an additional pair of similar contact bearing members may also be secured in the insulator stack beside the contacts 26, 28. The lower projection of one of such members is identified as 27 in Figure 2, the other being in register therewith and obscured in this view. Another set of bolster plate mounted contacts driven by the vibrating motion of the armature 30 is disposed for cooperation with the second set of contacts on the side arms 27, 29. These contacts lie directly behind contacts 26, 28 in Figure l and, being of similar size and shape, are obscured in this view. Their arrangement is, however, obvious from the figure. The bolster plates carrying the second set of contacts may be supported from the same spring hinge.

The position of the side arm 26 is adjusted by rotating the adjusting screw 34, which may be tipped with a synthetic jewel 32, in the side frame member 10. When the proper adjustment has been obtained, the screw 34 is locked in position by the use of a locking nut 36. A similar adjusting screw arrangement is associated with the side arm 28. The side frame 10 is also cut away at 35, 37, 38, and 40 to receive projecting lugs on the ends of the coil spool 42. The coil 44 mounted on the spool 42, embraces the movable armature 30. By virtue of this arrangement, the passage of current through the coil 44 develops a magnetic field in the armature 30 causing it to be attracted to one side or the other of the air gap defined by the faces of the pole pieces 20, 21.

The vibrator illustrated incorporates two independent contact assemblies. The one facing the viewer in Figure l is a single pole, double throw assembly connected with the ends of the operating winding 44, which is centertapped. The rear contact assembly is similar in structure and governs the flow of current in the power circuit. Isolation of the electric circuits in this manner minimizes the reaction between conditions in the load circuits and the mode of operation of the vibrator itself.

The perspective view of Figure 3 affords a better opportunity for visualizing the configuration of the pole pieces 20, 21. The magnet 18 is composed, as noted above, of any suitable permanent magnetic alloy, while the pole faces 20, 21 are made up from a softer magnetic alloy. The pole faces have the shape of opposing truncated quadrangular cones in which the truncating plane is inclined at an angle to the altitude of the cone. An

edge out or rebate is taken out of the lower portion of the opposing cones.

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