US2286848A - Vibrator - Google Patents

Description

l June 16, 1942. w. w. GARsTANG VIBRATOR Filed July 17, 1940 a .ai

Patented June 16, 1942 VIBRATOR William W. Garstang, Indianapolis, Ind., assignor to Electronic Laboratories, Incorporated, Indianapolis, Ind., a corporation of Indiana Application July 17, 1940, Serial N0. 345,999

(Cl. 20G-90) 4 Claims.

The present invention relates to improvements in vibrator switches and particularly to that type of vibrator switch wherein a reed is adapted to be rapidly vibrated through the instrumentality of an electromagnet for periodically interrupting an electric circuit.

This type of switch, in the commercial art, is frequently used for converting direct current into alternating current in a circuit wherein there is provided a transformer, the circuit of which is interrupted and reversed through the primary coil thereof at high frequency for causing the secondary to deliver to the load circuit an alternating current.

In certain types of these circuits, the frequency of vibration of the reedis necessarily'so high that there is a great tendency on thepart of the magnet for operating the reed to become abnormally hot due primarily to the fact that a poor magnetic path is provided for the magnetic flux of the electromagnet. As the result of this heating, considerable trouble is experienced, not only in the maintaining of the operation of the switch which will, under this extreme heating, disintegrate more rapidly but also, due to this extreme heating of the electromagnet, the frequency of the .operation of the reed itself will vary. In certain circuits, a fluctuation or a variation in a frequency of the reed which accordingly will cause a fluctuation or variation in the frequency of the current eventually delivered, will materially affect the operation of the load imposed on the load circuit.

It is one of the. objects of my invention to provide a vibrating reed switch which will stand up under severe conditions and which will not generate undue heat.

For the purpose of disclosing the invention, I have illustrated an embodiment thereof in the accompanying drawing, in which:

Fig. 1 is a side elevation of a vibrating reed switch embodying my invention;

Fig, 2 is a front elevation thereof.

In the embodiment illustrated, I preferably provide a frame comprising the two side members I and 2 which are formed of suitable metal and between which the Various parts of the switch are adapted to be clamped. The switch proper comprises a vibrating reed 3 having a normal frequency corresponding to the frequency of the alternating current intended to be delivered. This reed has mounted thereon on opposite faces thereof two pairs of contacts, each pair being made up of oppositely mounted spring fingers 4 and 5 riveted or otherwise secured to the body of the reed and carrying at their outer ends suitable contact points 6 6. Cooperating with the two pairs of contacts carried b'y the reed are two pairs of relatively stationary contacts, each pair comprising spring fingers I and 8 disposed on opposite sides of the reeds and carrying contacts 9--9 adapted to cooperatewith the contacts 66. These sets of contacts are adapted for the opening and closing of the circuit to be controlled. In addition to the above-mentioned sets of contacts, I preferably provide on the reed an additional contact II) adapted to engage a relatively stationary contact II extending inwardly from the side 2. The reed and its associated relatively stationary contacts are clamped between the side members I and 2, with suitable spacers I2 disposed between the sides and the relatively stationaryvcontacts and between the stationary contacts and the reed. Thereiare certain of these spacers, as for instance I3 and I3', formed of insulating material, so that the reed itself and the relatively stationary contacts will be insulated from one another and from the side walls I and 2 of the frame.l The relatively stationary contact members I and 8 are in themselves flexible reeds which, however, are stiffened by backing members I4 and I5 so thatthey will not vibrate and will be held in a relatively stationary position. These stiffening members are also connected to additional braces I6 and II, being connected thereto by set screws I8 extending through openings in the carrying reed I and 8. These set screws I8 provide means whereby the distance between the contacts 6 and 9 may be very nicely adjusted- For vibrating the reed 3, I provide an electromagnet, the winding I9 of which is wound upon and energizes a core 2U. This core is formed of laminated sheets and is provided with a pair of outer poles 2| and 22 and a central pole 23. The winding I9 is actually wound upon the center pole 23 which is shorter than thektwo outer poles 2I and 22 and it is to be noted that the end 24 of the reed 3 lies between the two pole pieces 2I and 22 closely adjacent the same with its end very closely adjacent the end of the center pole 23. The normal position of the end 24 of the reed, which comprises the armature of the electromagnet is offset or off-center with respect to the core of the winding so that when the winding is energized, there will be a tendency for the magnet to pull the end of the reed 4 toward the center against its natural or normal bias. The

core 20 of the electromagnet is clamped between the side members I and 2 through suitable clamping bolts 2'5 which extend through the side members I' and 2 and through the laminated core, suitable spacer sleeves 26 being provided for maintaining the laminated core in its position midway between -the two side members I and 2.

In the structure illustrated, in operation, when circuit is closed through the energizing winding I9, the magnetic flux set up in the pole pieces and tending to pass through the armature end 24 of the spring will cause the reed 6 to move toward the center position between the two sides I andV 2. This, of course, will separate the contacts I0 and II and as the contacts I0 and II are in the circuit of the winding I9, the circuit through the winding I9 Will thus be broken, thereby deenergizing the electromagnet and permitting the reed under its own bias to swing back to again close the contacts I0 and II. The reed is thus set in vibration and, due to thc fact that an'extremely good magnetic path is provided for the magnetic flux in the pole pieces 2I and 22 with a minimum of air gap between thearmature 24 of the reed and the pole pieces, the switch can operate forlong periods of time with a minimum of heating effect and with the maximum of power. 'I'his is extremely advantageous where the reed is operated at extremely high frequencies.

I claim as my invention:

1. In avibrator reed switch, in combination, a f

pair of at side plates, an electromagnet including a laminated core having a pair of legs forming pole pieces, means for supporting said electromagnet between said plates and at one end thereof with the laminae of said core disposed in I edges closely adjacent the active faces of said A pole pieces, said armature being normally disposed eccentric with respect to the magnetic force of said electromagnet and swingable transversely to the planes defined by the laminae of said electromagnet, contacts on said reed, relav'tively stationary contacts adapted to cooperate with said reed contacts, and means for supporting said stationary contacts between said plates.

2. In a vibrator switch, in combination, a pair of flat side plates, an electromagnet including a laminated substantially E-shaped core, means for supporting said electromagnet between said plates and at one end thereof with the laminae of said core disposed in planes parallel to the ,y end of said core facing inwardly, the outer legs Cil of said core being longer than the center stem and forming pole pieces having active faces 1ocated in a plane transverse to the plane of said plates, a vibrating reed supporting at its free end an armature with at least a portion thereof disposed between the outer legs of said electromagnet with its side edges closely adjacent the faces of said outer legs and with its top edge closely adjacent the bottom face of the center stem oi' Asaid electromagnet, said armature being `nor mally disposed eccentric with respect to the magnetic force of said electromagnet and swingable transversely to the planes dened by thelaminae of said electromagnet, contacts mounted on said reed and relatively stationary contacts adapted to cooperate with said reed contacts, and means for supporting said reed and said relatively stationary contacts between said plates.

3. In a vibrator reed switch, in combination, a supporting frame, an electromagnet mounted at one end of said supporting frame including a laminated open ended magnetic core formed with parallel side legs and a top cross piece, a vibrating reed, means for supporting one end of said reed at the opposite end of said frame, said reed at its free end supporting an armature in a position with at least a portion thereof disposed between the extremities of said legs and normally eccentric to the lines of magnetic force of the pole pieces formed by said legs and swingable transversely to the planes defined by the laminae of said magnet, contacts carried by said reed, stationary contacts cooperating with said reed contacts, and means for supporting said stationary contacts in said frame.

4. In a vibrator switch, in combination, a supporting frame, an electromagnet mounted at one end of said frame and including a laminated open ended E-shaped magnet core, the outer legsy of said magnetic core being longer than the center stem thereof, a vibrating reed, means for sup'- porting one end of said reed at the opposite end of said frame, said reed at its free end supporting an armature in a position with at least a portion thereof disposed between the extremities of said side legs normally eccentric to the lines of `WILLIAM W. GARSTAN G.

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