US2528922A - Circuit maker and breaker - Google Patents

Description

N 7, 1950 F. TALBOT 8,

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 3 Sheets-Sheet 1 FIG. I F|G.2

INVENTOR FRANK A. TALBOT,

Nov. 7, 1950 F. A. TALBOT 2,523,922

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 s Sheets-Sheet 2 FIG. 3 FIG. 4

sow X 2 52- a 47 46 l o '48 52- 50 46 l 5a 54 49 5s 54 49 INVENTOR FRANK A. TALBOT,

7*" ATTORNEYO Nov. 7, 1950 F. A. TALBOT 2,528,922

CIRCUIT MAKER AND BREAKER Filed Dec. 12, 1946 3 Sheets-Sheet} .04 magic-1.9 QFIG.IO

Zmventor FRANK A. TALBOT,

Patented Nov. 7, 1950 CIRCUIT MAKER AND BREAKER Frank A. Talbot, Baltimore, Md., assignor of onehalf to Robert E. Barry, Washington, D. 0.

Application December 12, 1946, Serial No. 715,668

'9 Claims.

This invention relates to improvements in circuit makers and breakers, and more particularly to a snap-action lighting switch of rugged construction which provides safety, dependability, minimum maintenance and positive operation for use in locations where atmospheric conditions are adverse.

One of the objects of the invention is to provide a novel snap-action mechanism applicable to various kinds of switches.

A further object is to supply a lighting switch, the contacts of which may be immersed in oil, and a switch provided with novel thermostatically-controlled means for short circuit and overload protection.

Another object of the invention is to furnish a switch of this character having an operating lever of trim design, but large enough to provide a good, comfortable grip assuring positive and easy operation, and one which may be used to indicate the electrical position of the switch so long as the thermostatic control is in a certain position.

A further object is to supply the switch with renewable contactsheavy duty, series break. This large contact area and series break prevents the concentration of burning. In accordance with theinvention, the contacts are self-aligning-constant pressure.

A still further object is to provide a snapaction switch including a contact actuator, that is constantly urged to open-switch position, but normally held in closed position by a thermostatically-controlled latch.

With the foregoing objects outlined and with other objects in view, which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a side elevation, partly in vertical section, of one embodiment of a switch in accordance with the invention.

Fig. 2 is a rear elevation of the same.

Fig. 3 is a front elevation with the switch in .closed position and with the thermostaticallycontrolled latch in latched position. Fig. 4 is a view like Fig. 3 with a front cover removed and showing the switch in open position and the thermostatic latch in unlatc'hed position.

Fig. 5 is a front'elevational'view of a modiflcation of the snap-action mechanism shown.

connected to an operating means and a contact carrier, with parts broken away to facilitate illustration. In this view, the switch is shown in closed position.

Fig. 6 is a top plan view and Fig. 7 an end view, respectively, of the structure shown in Fig 5.

Fig. 8 is a view similar to Fig. 5 but showing the switch in open position.

Fig. 9 is an end view and Fig. 10 a side elevation, respectively, of a pin forming part of the mechanism illustrated in Figs. 5 to 8, inclusive.

Referring to the switch illustrated in Figs. 1-4 of the drawings, Ill designates a panel of insulating material adapted to be fixedly arranged in an upright position in any suitable casing (not shown), so the lower portion 0f the mechanism may be immersed in oil.

A cover or face plate II is positioned forwardly of the panel and is rigidly connected with spacing arms [2, detachably secured to the panel by means of screws l3 or the like. The arms act to rigidly support the plate II and to space it from the panel.

A horizontal rock shaft [4 is journalled in the face plate and provided at the front end thereof with an operating lever l5, of trim design, but large enough to provide a good grip to assure positive and easy operation of the shaft. Such handle may be employed with indicia (not shown) on the plate I I to indicate whether the switch is open or closed.

A toggle actuator I6 is fixed to the shaft and is provided at its top with a nose or cam IT to engage and cooperate with pairs of toggle links l8 and IS. The links'l8 are fulcrumed at one end on a fixed pivot 20 supported by the plate II, and the links [9 are pivotally mounted at one end on a fixed pivot 2|, also supported by said plate. The opposite ends of the links are pivotally connected respectively at 22 and 23 to opposite lateral arms 24 and 25 of a three-armed lever 26. The lever has a centrally disposed slot 21 for the reception of a stud 28 which projects forwardly from the upper end of a contact carrier or actuator 29. The stud is pivotally connected to the part 29.

The third or upwardly extending arm 30, of the three-armed lever, is connected to one end of a coil spring 3|, the opposite end of which is anchored to the top portion of the plate ll so that the spring acts to move the three-armed lever either in clockwise or counter-clockwise direction after the arm 30 has swung either to the left or right after passing dead center, in pivoting on the stud or pin 28. The latter is fixedly mounted on the upper end of a substantially triangular lever 32, rotatably supported on the shaft it. As the pin 28 extends into the slot 21, it will be obvious that each time the three-armed lever 25 is shifted, the pin 28 will also be shifted either to the right or left, and in order to insure snap-action, a coil spring 33 surrounds the shaft l4 and has-its ends extending into notches 34 and 35 of the respective forward'extensions 35 and 31 of the actuator l6 and the lever 32.

The medial portion of the contact carrier 29 is pivotally connected to a stud 38 which projects entirely through the contact carrier and forms a latch element 39 at-the front thereof (Fig. 1). The opposite end portion of the stud 38 extends through a hole 40 oflargerdiameter than the stud, in the panel l0, and is fixedly connected to an oscillating member or support ll, pivotally mounted at 42 on the rear of the panel. A. ,coi1. spring .43 (Fig. ,2) hasone ,of its endsanchored to the oscillating..memb.er, at 44 andits opposite end anchored-to a fixed terminal 45 at the rear of the panel. Due to'this,cons truction, the spring lfi tends to... constantly move the contact carrier 29in a clockwise direction (Fig. 12)

about the fulcrum pin "28, from which the con-.

tact carrier is suspended.

'The contact carrier 29jfixe'dly carriesat its.

lower.end, a bracket .46'having an. aperture .to slidably receive a shaftor rod 4'! havinga head 48 atone end to'limit "the movementof the bracketin one direction. .A contact bridge .49 is loosely mounted on therod between a cotter pin 0,,extending through a, hole in the rod. and a.coil spring .5l that abuts, at one end against the bracket 86 and atthe otherend, against the bridge. The rod also moves axially in a guide hole extending through a "bracket 52 held in place bycylindricalpontacts 53and 54,, removablyfixed to the front of the panel andarranged atright angles thereto. The bracket 52 is of insulating material so that currentcannot pass from the lead-in contact 54to the contact 53 whenthe switch is ,open, but, whenit is closed, allowsthe current tofiow from 54 through the bridge 49 to the contact53.

Astud 55 is'fixed to the front'ofthe panel, to bev contacted by the lower end of the contact carrier .29 to limit opening movement of the switch.

A bi-metallic or thermostatic element has'legs 56 andE'! connected to a lower transparent face plate .58 (supported bythe contacts 53-54). as shown in Figs. 1, 3 and 4, and the leg 56 is in electricalconnection with-the contact 53. These legs are of L-shape (Fig.1) with curved portions 59 arranged adjacent the bends therein and the horizontal portions 60 of the legs-are connected to one anothenas indicated-attl. .The linking portionfil of the bi-lnetallic element carries a depending latching elementi62, cooperating with thelatching element 39 to hold the contact carrier129 in a.certa in position solong as the bimetallic element is in normal position, ,or the fullline position shown in'Fig. 1. When the thermostatic element is affected by conditions in the line, heat ,willcause the part 6! to rise to the dottedlineposition (Fig. 1), so that the part 62, will release thelatch element 39 and allow the spring 43 toshift the. contact carrier to openswitch position, as indicated in Fig. 4.

Current. leaves the switch througha terminal 63 in electric contact with the legs5l of the thermostatic element.

In operation, assuming that the switch is closed, as indicated in Fig. 3, and the thermostatic latch element 62 is in engagement with the latch element 39 of the stud 38, on which the contact carrier 29 pivots, if the operating member or handle I5 is moved counter-clockwise, the nose or cam U will engage and raise the ends of the toggle links [8 which turn counter-clockwise about the pivotzpoint 20. At the same time, the actuator IS, in m'ovingcounterclockwise, will act by means of its extension 36 onone leg of the spring 33, to tension the latter while the member 32 remains stationary. As soon as the-pivot point 22 rises sufficiently to turn the arm 30 of the three-armed lever clockwise, beyond. deadcenter, the spring 3! will act to throw the arm 30 into the position shown in Fig. 4, and

as the'toggle mechanism snaps into position, to placexthe axis of the pivot 23 below the axis of the pivot 22, the spring-33 will recoil so that oneofitsdegs will act on the extensiont'l, of the member 132 to turn the latter-counter-clockwise. Asthemember 32 carries the pin .28,'that pin willact-to move the upper end of the contact carrier .29 toward the left, and as the central portion ofthe contact carrier pivots on the stud 38, it is obvious that the bracket 46 will act on thehead 430i theshaft 41 to move the bridge 49,away. from the contacts53 and .54.

If the handle l5'is now turned in a clockwise direction, an opposite action will take place so as to closethe switch.

While the switch is closed, if any disturbance inlthe circuit should cause the bi-metallic memberto act to raise the latch element62, the contact carrier 29 is automatically turned counterclockwise about the pivot'28 to open the switch. Thisaction maybe readily. understood from Fig. 2 where it may be'seen that 'the 'pin'38, if not held inthefull line position by the thermostat,

willibe caused bythe spring l3, to travel with the member .41 counter-clockwise about the'pivot 42 so asto shift the contact carrier aboutthe pivot 28 until the, lower end of. the contact carrier .is halted by the stop. 55. 7

As long as thethermostatic element isin the dotted line position shown ;in'Fig. 1, the latch cannot function and hence eventhough the snapaction mechanism at the upper end .portion of the device isjactuated, it will'have ,no effect on opening or closing of the switch because the stop 55 will then function as a fulcrum,'and 'the'contact carrier will'simplyturn aboutthis fulcrum when the pin 28' is moved'towardithe right or towardthe left.

In Figs. 5 to 10,. inclusive, I have illustrated the snap-action'mechanism-as usedfora large safety switch. This is similar to the'switch disclosed in'Figs. 1 to {Linclusive except for the latching spring and center pin-of toggles. In Figs. 5 to 10, 10 indicates a mounting panel through which a horizontal pivot bolt H extends. An actuating plate 1.2 ispivotally mounted thereon rearwardly of .thepanel, and provided with a rearwardlyextending horizontal pin"'l3 to which is attached a vertically reciprocating. handle or. operating member 14, employed in oscillating the actuation plate 12 vertically on the bolt.

Arranged at the front of the panel and also pivotally mounted. on the bolt, is a driven plate 15.. Theactuatingplate .12is provided withan arcuate slot 16 arranged concentric to the axis of the bolt.

Theplate 15 is provided witha projecting ear 1'! in which is journalled a pin 18 (Figs. 9 and 10) having end portions I9 provided with oppositely disposed flat sides 80. The fiat sided ends of the pivot pin extend into straight slots 8I provided in front and rear three- armed levers 82 and 83, spaced apart and connected together by pivot pins 84, 85 and 86. A toggle link 81 has one of its ends connected to the pin 84 and its opposite end pivotally connected to a stationary horizontal stud 88 mounted upon the front of the panel I8. Another toggle link 89 has one of its ends pivotally connected to the pin 86 and its other end pivotally connected to a fixed stud 90 projecting from the panel ID.

A slidable stud 9| is pivotally connected to the pin 85 and slides in guide bracket 92 fixed to the front of the panel. A coil spring 93 surrounds the stud and serves to act upon the three- armed levers 82, 83 so as to hold the toggle mechan sm in either of its two positions, after it passes dead center. A horizontal stud 94, fixed to the lever 83, projects rearwardly therefrom through a slot 16a in the panel I9, into the registering slot I6 of the actuating plate, and is actuated each time an end of the arcuate slot I6 contacts the pin durin the turning of the actuating member by the handle 74. Another horizontal stud 95, fixed to the driven plate I5 projects through an arcuate slot 95 in the panel and is arranged alongsideof the pin 1 3 of the actuating plate.

A coil spring 91 surrounds the pivot bolt II and has its end portions crossed at 98, and its legs 99 and I 98 arranged at opposite sides of the pins I3 and 99, so that the spring will be tensioned when one of the pins is moved relatively away from the other.

A driven rod IEJI, which may be formed of parallel plates, has a roller I82 at its upper end movable in a cam slot I03 of the driven plate I5. Power is delivered by the driven member to the rod or link I by the cam slot, and such slot is curved to give a variable mechanical advantage, so that high pressure is set up on electrical contacts I84 and I 95 by the bridge I06 of the switch after the switch is closed (Fig. In this figure, the mechanism is shown for maximum pressure or while the switch is in the on position. Of course, the bridge I88 is carried by the link IOI. A swinging link ID'I is pivotally connected at one end to the axle ofthe roller I02, and is pivotally connected, at its opposite end to a fixed stud I 98, projecting from the front of the panel I0.

In the operation of this modification, it may be seen from Fig. 8 that if handle M is depressed to cause the driving member I2 to move clockwise, the pin '53 will move the leg I80 of the spring 91 downwardly so as to tension that spring, and as soon as the lower end of the arcuate slot I8 of the driv ng member I2 contacts the pin 94, the latter will move with the driving member in a clockwise direction about the axis of the bolt II As the stud S4 is fixed to the three-armed lever, the latter will turn in a counter-clockwise direction about the axis of the pin 9 so as to shift the toggle links 8?, 39 until the three-armed lever moves over dead center, at which time the spring 93 will function to shift it from the position shown in Fig. 8 to the position shown in Fig. 5, and as the pin I9 connects the three-armed lever to the driven plate IS, the latter will be moved clockwise, under the influence of the spring 91, so as to cause the cam slot I03 to lift the link IUI to compel the bridge I86 to engage the contacts I04 and I05, as shown in Fig. 5.

When the parts are in the position shown in Fig. 5, they may be returned to the position shown in Fig. 8 by movingthe handle I4 upwardly.

From the foregoing, it is believed the construction, operation and advantages of the invention may be readily understood, and it is apparent that changes may be made in the details disclosed without departing from the spirit of the invention, as expressed in the following claims.

What I claim and desire to secure by Letters Patent is:

1. In a switch of the character described, a double toggle including a three armed intermediate lever and a pair of links, one end of one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means operatively connected to the remaining arm of the threearmed lever and adapted to yieldingly hold the latter in either One of two positions, an actuator operatively connected with the double toggle for initiating movement of the three-armed lever into either one of its two positions, a second spring means operatively connected to the actuator, an operating member for moving the actuator and tensioning the second spring means, a driven member actuated by the second spring means, and a contact actuator driven by said driven member.

2. In a switch of the character described, a double toggle including a three-armed intermediate lever and a pair of links, one end of one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means operatively connected to the remaining arm of the three armed lever and adapted to yieldingly hold the latter in either one of two positions, a pivotally mounted actuator cperatively connected with the double toggle for initiating movement of the three-armed lever into either one of its two positions, a second spring means operatively connected to the actuator, an operating member for turning the actuator and tensioning the second spring means, a driven member actuated by the second spring means, and a contact actuator driven by said driven means.

.3. In a switch of the'character described, a double toggle including a threearmed intermediate lever and a pair of links, one end of one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means operatively connected to the remaining arm of the three-armed lever and adapted to yieldingly hold the latter in either one of two positions, a pivotally mounted actuator operatively connected with the double toggle for initiating movement of the three-armed lever into either one of its two positions, a second spring means operatively connected to the actuator, an operating member for turning the actuator and tensioning the second spring means, a driven member actuated by the second spring means and pivotally mounted for movement about the same axis on which the actuator .turnsyand a contact carrierdrivenyby said driven member.

4. In a switch of the character described, a-

double toggle including a three-armed intermediate lever and a pair of links, one end of one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means oneratively connected to the remaining arm of the three-armed lever and adapted to yieldingly hold the latter in either one of two positions, an actuator operatively connected. with the double toggle for initiating movement of the three-armedlever into either one of its two positions, a second spring means operatively connected to the actuator, anoperating member for moving the actuator and tensioning the second spring means, a driven member actuated by the second spring means, and a contact carrier cperatively connected to the three-armed lever and -1noved thereby.

5. In a switch of the character described, a double toggle including a three-armed intermediate lever and a pair of links, one end of one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means operatively connected to the remaining arm of the three-armed lever and adapted to yieldingly hold the latter in either one of two positions, said three-armed lever being provided intermediate its opposed arms with an elongated slot, a pivotally mounted actuator for initiating movement of the three-armed lever into either one of its two positions, a pin pivotally mounted in the actuator and having a flat head slidably mounted in said slot, a second spring means operatively connected to the actuator, an operating member for rotating said actuator and tensioning the second spring means, a driven member actuated by the second spring means, and a contact actuator driven by said driven member.

6. In a switch of the character described, a

double toggle including a three-armed intermediate lever and a pair of links, one end of one link being turnable about a fixed axisand having its other-end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its other end pivotally connected to an opposite arm of the three-armed lever, spring means oper-atively connected to the remaining arm of the three-armed lever and adapted to yieldingl hold the latter in either one of two positions, a pivotally mounted actuator operatively connected with the double toggle for initiating movement of said lever into either one of its two positions, a second spring means operatively connected to the actuator, an operating member for turning the actuator and tensioning thesecond spring means, a pivotally mounted driven member actuated by the second spring means and provided with guiding means having a portion tangent to the axis of rotation of the driven member, and a contact actuator operatively connected to said guide, means and actuated by said driven member.

7. In a switch of the character described, a double toggle including a three-armed intermediate- 8" lever anda pair of links, one endof one link being turnable about a fixed axis and having its other end pivotally connected to an arm of the three-armed lever, the other link having one of its ends turnable about a fixed axis and its means operatively connected to the actuator, an'

operating member for turning the actuator and tensioning the second spring means, a driven member actuated by the second spring means and turnable about the same axis as the actuator, said driven member having a tangentially arranged slot, a roller travelling in said slot, and

a contact actuator connected to the roller and driven by the driven member.

8; In a switch of the character described, a

supporting panel, a manually controlled mechanism supported by said panel and arranged at one." side thereof, a contact actuator having an end portion pivotally connected to said mechanism andoperated thereby, a support pivotally mounted on the opposite side of said panel, said panel, being provided with an aperture between the point where the support is pivotally mounted and the place where the contact actuator is pivotally connected to said mechanism, a trigger connecting the medial portion or the actuator to said support and extending through said aperture, resilient means connected to the support for constantly urging the contact actuator into openswitchposition, and thermostatic means engageable with the trigger and responsive to a condition' in the circuit controlled, to prevent the contact actuator from moving in response to said resilient means.

9. In a switch of .the character described, a manually controlled mechanism, a contact actuator pivotally connected thereto, a rod slidably supported by the actuator, a bridge slidably mounted on the rod, stationary contacts with which the bridge' cooperates to complete a circuit, a spring mounted on the rod and arranged to be compressed when the bridge engages the con-- tacts for yieldingly pressing the bridge against said contacts, resilient means constantly urging the contact actuator and bridge into open-switch position, and thermostatic means in electrical connection with one of said contacts and responsive to a condition in the circuit controlled, to prevent said actuator from moving in response to said resilient means.

FRANK A. TALBOT.

REFERENCES CETEI) The following references are of record in the

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