US993946A - Cut-out for electrical circuits. - Google Patents

Description

y J.. T. BBECHLYN. OUT-OUT FOB BLECTRIOAL UIRGUITS. APPLIDATIONNFILED AUG. 17; 1908.

Patentbd May 30, 1911.

3 SHEETS-SHEET Jun-IN T. DEECHLYN.-

J. 'I'. BEECHLYN. I GUT-OUT FCR ELECTRICAL CIRCUITS.

APPLICATION IILBD AUG. 17, 1908.

3 SHEETS-SHEET 2 Patented May 30, 19M.

J. T. BEECHLYN.

CUT-OUT FOR ELECTRICAL CIRCUITS.

APPLIOATION Hmm me. 17, 190s.

Patented May 30, 19u

...n T n Tm A Nm WE NE .1E T. N H n JV UNITED sTAppsMPATENT orario-E.-

JOHN T. BEECHLYN, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CUT-OUT `FOR ELECTRICAL CIRCUITS.

To all whom it may concern:

Be it known that l, JOHN T. BEECHLYN, a. subject ofgthe King of Denmark, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Cut-Outs for Electrical Circuits, of which the following is a spccication.

This invention relates to cutouts for elec-4 trical circuits and its objectl is to provide a simple and reliable device for opening a circuit after a predetermined expiration of time. Such switches are useful in connection with heating appliances, some et which are liable to become overheated it left too long On a closed circuit; or with lighting applianees which one wishes to extinguish at a certain hour, as i'or instance in show windows; or in' signaling systems, where a signal is to be changed after a certain time has elapsed; and so on.

My invention utilizes a dash-pot as, the time-limiting element, but the plunger therein is not connected mechanically with any outside mechanism. 'ljhe plunger is made of magnetic material, and is subjected to the influence o1 a magnetic field, by reason of which it is lifted slowly through the liquid in the closed dash-pot, being retarded by the usual valve. When the plunger arrives at a predetermined level, it practically closes the magnetic path of an electromagnet, andgthe increase in magnetic iluxis utilized to effect' a release ot' the detent which holds the switch closed and allowing 1t to open and break the circuit.

ln the accompanying drawings Figure 1 is a side elevation of one torni ot' my improved time switch in the closed position, the cover being in section; Fig. 2 is a front elevation; Fig. Si is a side elevation showing the switch open; ltig. l is a fronty elevation with the cover removed; Figs. 5 and (l show the locking and tripping mechanism, yclosed and open, respectively; Fig. T is a longitxulinal section of the dash-pot, plunger and coil; and Fig. 8 is a top plan view of one ot' the jaws.

The ope 'ating parts are mounted on a base 1. of insulating material, to which is secured a metalic plate 2 and from which two parallel flanges t, Ll project at right angles. ',lhe flanges have alined pel-iterations in which is itted a cylinder 5 to serve as a dash-pot.. The upper flange 3 has an upturned lug 6 Speciication of Letters Patent.

Application ined August 17, 1908.

Patented May 3o, 1911. Serial NO. 448,795.

bearing against the dash-pot'and not only securing it in place but enabling it to be vertically adjusted. The dash-pot depends considerably below the flange 4, and is her- 'through which is tapped a setscrew 7 largely upon the size' of the port which the valve controls.

The upper part of the daslrpot is surrounded by a coil 10 resting on the lower flange 4 and held in place by two projections 11 from the upper flange 3, which are bent down upon the top of the spool containing the coil.

Depending from each side of the lower flange 4t is a pair of ears 12 13, and pivoted to the front ears 12 is a U-sliaped switch lever 11 which hangs below the bottom of the dash-pot and carries the bridging contact-blade 15, insulated from the lever by strips 16 of mica or the like. The contactblade cooperates with two clips 17 forming the terminals of a break in one of the line wires 1S. The other wire 1S extends unbroken, and the coil 10 is connected across the Vtwo by the wire 19. rl`he switch-lever is urged open by a spring 20 attached to its upper end and to a lug 21 on the plate 2. ln order to lock the switch closed, the

switch-lever carries a light resilient finger 22 provided with a shoulder 23 which snaps up behind a stationary detent 2-1, preferably a pijn projecting from the bottom of the dash-pot. A stop 25 limits the throw of the .switch-lever in closing.

The automatic tripping mechanism comprises a. pair of ironfjaws 26 27 whose shape is that of an inverted U.` The lower ends of these jaws are pivoted respectively on the ears 13 l2 on the Atiange 4, and their upper cross-bars contain semi-circular notches 2S adapted to tit the dash-pot so that the two jaws can close around it. The pivotal pointsof the jaws are located near the outer edges of the jaws, as shown in Figs. 5 and 6. The inner adjacent. edgesvof the jaws are gpivotally attached to a U-shaped strap 29 which passes under the dash-pot and is provided wit-h a perforation which has a sliding 1V lit on the pin 2st. The extent to which the pin projects through the strap can be adjusted by adjusting the dash-pot up or down by means oi the set screw 7. The pivotal connection between the jaws and the strap is preferably made by cutting shallow sawlieys in the jaws and bending the upper ends of the strap outward to engage loosely with said keys.

A light tension spring is attached at one end to the upper end of the rear aw and at its lower end to the base 1, and serves to urge said jaws apart and lift the strap 29.

A lug 3l on the front jaw acts as a stop tor.

the switch lever when the latter is thrown open by the spring 20. rlhe cover 32 carries two push-buttons 33 3l mounted on light springs 35 secured to the inner side of 'l said cover.

'lhe upper button 33 enables the operator to cl'ose the upper ends of the jaws upon the dash-pot. The lower button 34 enables the switch 'to beclosed. An indicator target 3G on the switch lever, bearing the words On and Gili, cooperates with a wind i 37 in the cover to show the condition of the switch.

The operation is as follows: l/Vhen the switch is closed, the jaws, being released from the pressure of the lever on the lug 3l will be forced apart by the spring 30 thereby lii'tiixg the strap a short distance, and allowing the pin to project far enough below it to engage the shoulder on the spring linger and thus lock the switch closed. The closing of the circuit energizes the coil, which magnetizes the jaws, but they are not attracted toward each other because of their similar polarity. The weight of the plunger has caused it to sink to the bottom of the dash-pot, but the energized solenoid coil now exerts an upward pull on it, so that, retarded by the valve, it rises slowly through the iiquid; being in effect a movable core for the solenoid. lts upper end acquires a polarity opposite to that of the jaws, so that when at the expiration of the time limit, said end rises to a position between the semicircular edges `of the jaws they are strongly attracted and close upon the dash-pot when the attraction overcomes the tension' of the spring 30. As the jaws snap together', the strap is forced downward, thereby pushing the spring finger ott' the pin and releasing the switch, which Ais instantly pulled open by the spring 20. The coil being now out of circuit ceases to exert any pull on the plunger, whose weight semis it quickly to the bottom of the dash-pot, the valve opening freely and permitting the liquid to pass through the plunger as it descends. .ln case it is desired to open the switch before the expiration of' the time limit, the button can be shed in, forcing the jaws together and tri f g the switch-locking devices.

Wn .ns switch is installed in connection with a heating device, such for instance as a iiat iron, it fulfils the same requisite as a thermostat. ln other words it eliminates all danger from lire due to leaving the ilat iron with the current turned on, it elliects a regulation o'tl the heat, as an excessive temperature cannot develop within the usual time limit ol the switch, say ten or fifteen minutes; it reduces the operating expenses, as the iron is liable to become too cold rather than too hot, by reason of thc shutting otl;l ol. the current. l`he switch, however, opens with a sharp audible sound, so that the operator is warned and can be ready to close the switch again iiE the iron begins to get cool. On account of its sturdy construction and permanent stationary mounting, the operation of this time-switch is positive and reliable, and inasmuch as it can be substituted for the ordinary line switch it does not greatly increase the cost of the heating outtit. Moreover, it can be applied to existing installations with a minimum of labor and expense.

Vhat lf claim as new and desire to secure by Letters Patent oi the United States, is,

l, A time switch comprising an electromagnet coil, switch tripping mechanism containing movable magnetic elements disposed in the field of said cojl, a core movable longitudinally oi said coil to vary the effect of the magnetic field on said magnetic elements, and means for retarding the movement oi said core.

A time switch comprising an electromagnet coil, switch tripping mechanism containing' operative elements polarized by said coil, a core movable longitudinally of said coil into and out of proximity to said elements and polarized by said coil opposite to the polarity of said elements, and means l'or retarding the movement of said core.

3. A, time switch comprising a dash-pot, a magnetic plunger movable therein, an electromagnet coil surrounding said dash-pot, and switch tripping mechanism provided with movable elements arranged in the field or' said coil and responsive to variations of the magnet-ic flux produced by movement of said plunger. lt. A time switch comprising a dash-pot, a magnetic plunger therein provided with a check-valve to retard upward movement, an electromagnet coil concentric with the upper portion of said dash-pot, movable magnetic jaws adapted to close upon the upper end ot' said dash-pot, and switch tripping mechanism actuated by said jaws.

5. A time switch comprising a dash-pot, an electron'iagnet coil surrounding said dashpot, two iron jaws pivoted to close upon the upper end oit said dash pot, a magnetic plunger movable in said dash-pot into and out otl proxin'iity ot' said jaws, a strap suspended from said jaws, a switch lever and a essere coil adapted to be connected in circuit by said switch, a movable core adapted to close the magnetic path of said coil, means for retarding the movement of the core, and means responsive to the linx insaid path for actuating the tripping mechanism.

7. A time switch comprising a dash-pot, a magnetic plunger movable longitudinally thereof, an eleotroni'agnet coil surrounding said dash-pot and adapted to be energized upon closing said switch, and magnetic switch tripping mechanism so pivoted that said plunger moves into and. out of proximity thereto to vary the effect of the magnetic eld thereon.

8. A time switch comprising a plate having two perforated Hanges, a dash-pot held in the perforations, a magnetic plunger in said dash-pot, a coil surrounding said dashpot and supported on one of said anges, two jaws pivoted to the lower flange and having notches adapted to close upon said dash-pot, a spring for urgingsaid jaws open, a switch-lever adapted to connect said coil in circuit pivoted to the lower iange and carrying a spring finger, a detent to engage said finger, and a strap carried by said jaws for releasing said finger from said detent.

In witness whereof, I have hereunto set my vhand this fourteenth day of August,

`JOHN T. BEECHLYN WVitnesses JOHN A. McMANUs, Jr., HENRY O. VVESTENDARP.

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