US1419898A - Electric switch mechanism - Google Patents

Description

wf. RICHMOND. A vmscm'lc swlTcH MECHAMSM. APPLlc/mon :n. zp mn.' I7. m1.,

134,1 9,898. Patented Jun'ej13, 1922.

Brum ou( mqgm? UNITED STATES PATENT OFFICE.

WALTER :aIoIiuvIolvn or CHICAGO, ILLINOIS, AssIGNon- To JOHN ELLIOTT JENKINS,

OF CHICAGO, ILLINOIS.

i ELECTRIC SWITCH MECHANISM.

Specification of Letters Patent.l Patented June 13 1922.

original application inea ooiobor 24, 1911, serial No. 656,430. Divided and this appliootion inea Maron 17, 191,7. serial No. 155,424.

T 0 all whom t may conce/Mt.'

Be it known that I, IALTER RICHMOND, a citizen of the United States, and residing at Chicagmin the county .of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Switch Mechanism, of which the following isa specification.

My invention relates to electric switch mechanism which is especially adapted `for use in automatically controlled systems, such as those which are thermostatically regulated.

This application is a division of my application Serial No. 656,430, tiled October 24e. 1911.

It is an object of this invention to provide an electro-magnetic switch which can never assume a neutral position, and which can? not therefore become inoperative, requiring manual adjustment and correction.

It is another object of the invention to provide an electro-magnetic switch with a blow-out magnet, the energizing current of which will only be instantaneously utilized when the switch is shifted and which will pass through the arc at the switch, and to provide a switch of this character electromagnetic operating coils equipped with a magnetic sheath to concentrate the force of the magnet.

It is a further object of my invention to provide a controller .which maybe operated by a thermostat or the like, which is adapt* ed to selectively control `switch operating currents, and so associate the switch therewith that the circuit through thc con.g troller is opened after the same has made its switch Operating contact so that there can be no spark at the controller contact when the same is sulisequentlymoved away from the associated contact, a result cxtremely desirable in delicate apparatus; and to provide the combination of a primary controller (such as a thermostan) a controller, a switch and an electric element in which the primary 'controller operating through the controller and switch controls the element but in which no current passes through any part of the apparatus when the electric ,element is dead.

Figure 1 is a partly diagrammatical view of an electric switch and controller "mechanism embodying my invention, the energiz- 'field ofthe coil 5. y 'the arc which follows the blade when lit is inglvsolenoid magnet being shown kin section; anc f Figure 2 is a detailview showing the manner of connecting the magnet core to the switch blade. havey illustratedmy electric switch mechamsm in connection Vwith a system of electric heaters 1, 2, for purposes of illustration, although it is useful in other applications, as will be evident to engineers. The actuating magnet islof the solenoid type, having two energizing coils l, 5, which are adapted to move the core 6, in alternate directions to bring the switch blade 8 into engagement with the spring switch contacts`9, 9', or 10, 10. Instead of securing the stem 12 of the switch blade rigidly to the core, I form the stem into a yoke vframe 14 which surrounds the core so that the core may have a free initial movement within the yoke in both directions, striking the latter a hammerl blow to ensure a sudden movement of the switch blade from one lpair of spring contacts to the other pair. v

It is important when operating upon high voltage direct current, such as lighting circuits, that the arc which follows the switch bladeshould be extinguished. One of the important features of my invention resides in the provision for blowing out the 'are after the movement of the switch blade .in

either direction. The spring contacts 9, 9',

are located adjacent the coil 5, and within the influence of the magnetic `field of said coil, whereby when the blade 8 is moved from the contacts 9, 9', due tothe pull of ,thecoil 5 upon the core 6 the arc which follows lthe blade will be blown out by the In order to extinguish moving away from the `contacts 10, 10', I provide a'blow out magnet 16, which is connected ini` shunt to ,the coil 4;, and in the modification of the invention diSQlQSGd, S located so thatits magnetic field will be strongest Opposite the vupper portion of the contacts 9, 10, between which the arc is strongest. The part 16a of Figurel `is, the

`iron or magnetic core of the blowout magnet 16 and is so arranged as to lead the lines of force where theywill be most eii'ective in blowing outthe arc which occurs between contacts 10 and 9. The blow-Outrmagnet 16, together with Aits magnetic core 16a, is eiectively placed to extinguish the arc between the contacts 1() and 9, there being no arc between contacts 10 and 10 or between 10 and 9 because contacts 10 and 9 are electrically connected by a wire as shown.

It is to be particularly noted that when the switch is moving over 'from the contact-s 10, 10, to contacts 9, 9, the energizing circuit vtor the blow out magnet 16 will pass from the upper contact 10 through the are to the contact 9, through the switch blade 8 to the contact D, and back to the pole 35, so that the energizing current tor the blow out magnet is established through the arc blown out by the magnet at the time the circuit is broken.

'Ihe core 6 is somewhat longer than either of the energizing coils, so as to extend into both coils in any position to ensure the starting movement. I also provide an exterior magnetic sheath 18, tor the purpose of concentrating, and strengthening the magnetic field and thereby increasing the pull upon the core.

I have illustrated my electric switch mechanism in connection with a thermostatic controlling switch having a-switch arm 2O carrying a contact 22, adapted to engage contacts 23 and 24 alternately. The arm is normally restrained by the spring 28, the tension ot which can be changed by swinging the arm 29 into dotted line position. The switch arm 2O is moved against the spring tension by means ot a fluid expansion thermostat having a thermal tube 30 and an expansion box 31, one tace of which consists of a diaphragm and carries the anvil 32 which bears against the switch arm.

The current is brought in from the supply leads through the connection socket 35. lith the parts i-n the position shown, the current enters at thc socket contact 35, and passes by way of the relay spring contact 10', through switch blade 8, spring contact 10, and conductor 38 to the heater coils 1, 2, or other translating devices, and returns to the other socket contact 351 by way of the conductor 39. IVhen the circuit connections o't the relay or electro-magnetic switch' mechanism, are changed. by the movement oit the thermostatic switch arm 20, causing the contact 22 to engage the contact 241;, a circuit will. be established through the coil et. Thereupon the core 6 will be drawn over into the coil 4l, causing the blade 8 yto move 'from the contacts l0, 10', into engagement ,withthe contacts 9, 9', thereby breaking the circuit of the translating devices 1, 2. As the switch blade leaves the Contact 10, the arc which 'follows willtend to maintain the circuit across the gap between the contacts 9, 10, and by way ot the blade 8, contact 9 to the connectionA with the socket contact 35a, This are, however, will be extinguished laisses by the magnetic lield of the blow out magnet 1G, the pole 161L of which is adjacent to the gap. When the are is extinguished the circuit will be broken through the coil 1, blow out magnet 16 in shunt thereto, and the heaters 1, 2, and current will not flow through any part of the apparatus until the thermostatic switch arm 2O again establishes the circuit tlnrough the coil 5, by way of the contacts 22 and 23. In order that a circuit may be established through one relay coil or the other in all positions of the blade 8, I make the latter ol.i a greater width than the gap between the opposite pairs of spring contacts, as indicated by the intermediate position ot the blade shown in dotted lines.

It is to be noted that the circuit through the contacts 23 and 2a is opened immediately after the contact is made, so that upon the next operation by the thermostatic device, the contact 22 leaves a dead contact point, preventing sparking in the delicate portion ot the apparatus. In other words, the contact 22 never breaks but only makes the circuit.

An extremely powerful magnet in the smallest possible space can be used in this switch because the magnet is only in circuit a traction o'l a second and the heavy current employed is broken in the are which it blows out. It will thus be seen that the actual design oit this blow-out magnet can be varied between extremely wide limits and gives the designer the privilege ot placing the blowout magnet trom a mechanical point of view without being strictly confined to elect ical necessity.

Having now described my invention, I claim: Y

1. An electro-magnetic switch having a plurality of sets ol contacts, a switch blade adapted to contact with one set or another of said contacts, a magnetic core connected to said blade, a plurality ol5 energizing coils operatively related to said core, one set oli' contacts boing located within the magnetic .influence ot the adjacent coil, and a'blow out magnet having its magnetic lield einbracing the other set oli contacts, and arranged in a circuit including the arc at the adjacent contacts. Y

2. An electro-magnetic switch having a plurality of sets oit contacts, a switch blade adapted to contact with one set or another ol said contacts, a magnetic core connected to said blade. a plurality ot energizing coils operatively related to said core,'one set of contacts being locatedwithin the magnetic influence ot the adjacent coil, and a blow out magnet having its magnetic lield embracing the other set ot' contacts and being connected in shunt to the distant coil.

3. An electro-magnetic switch comprising two sets ol spaced contacts, switch blade adapted to Acontact with either set, and arranged and constructed to maintain contact with one set until after contact with the other set has been established, a pair of coils associated with said switch blade, and adapted to more the latter in opposite directions, a blow out magnet on a shunt circuit from one or" said coils, said circuit passing through the switch blade, whereby the energizing circuit of the blow ont magnet will pass through the arc to be blown out.

4f. In apparatus of the class described, two sets of spaced electric contacts, a switch blade adapted to contact with either or both sets, coils associated with said switch blades for shifting the latter in opposite directions, the circuit for one of said coils being broken upon shifting said blade, a blow out magnet in shunt from said coil, and means for permitting the circuit through the blow out magnet to be maintained through the arc caused by shifting said switch.

In witness whereof, I hereunto subscribe my name to this speciiication in the presence of two witnesses,

WALTER RICHMOND.

Witnesses:

SEBASTIAN HINTON, C. J. SHERMAN.

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