US2388617A - Switch construction - Google Patents

Description

Nov. 6, 1945. E. A. LINK 2,388,617

SWITCH CONSTRUCTION Filed May 17, 1943 4 Sheets-$heet l I 32 j INVENTOR. j I [aw/v A ///V/( WWgM/ NOV. 6, 1945. LlNK 2,388,617

SWITCH CONSTRUCTION Filed May 17, 1943 4 Sheets-Sheet 2 17?:4 INVENTOR.

E. A. LINK' Nov. 6, 1945.

SWITCH CONSTRUCTION F iled May 17, 1945 4 Sheets-Sheet 3 VII/4?; Il

INVENTOR. [mm/A //z//( E. A LINK Nov. 6, 1945.

SWITCH CONSTRUCTION 4 Sheets-Sheet 4 Filed May 17, 1943 4&

INVENTOR. [DIM/V A. Z/A/fi' Patented Nov. 6, 1945 swrrcn cons'rancrron Edwin a. Link, South Milwaukee, Wis., mum

toLineM aterlal Com Dilly, South Milwaukee,

Wla. a corporation of Delaware Application May 17, 1943, Serial No. 487,208

9 Claims.

This invention relates to a switch construction.

In greater detail, this invention relates primaritly .to a switch construction of the circuit breaker ype.

Objects of this invention are to provide a circuit breaker which has a quick make and a quick break, which has condition responsive means of the trip type, which is so constructed that it releases the circuit breaker so that the circuit breaker will open under predetermined conditions, and which is provided with a handle or other operating means for normally opening and closing the circuit breaker and for resetting ,the trip means, the trip means and the operating means being so related that the trip means will operate to'release the circuit breaker irrespective of the position of the operating means and irrespective of any motion that the operating means may be executing at the time the trip means operates so that the trip means is trip free and will operate no matter whether the operating means is forcibly held in closed position or is being moved from one position to another.

Further objects are to provide a circuit breaker which is so constructed that the circuit breaker cannot be closed until the trip means has moved back to normal position, and in which the resetting of the trip means is accomplished by moving the operating mean towards open position, such motion being followed by movement to closed position after the resetting of the trip means when it is desired to again close the circuit breaker after the occurrence of the predetermined condition,

Further objects are to provide a construction in which the trip means may be either thermostatically or magnetically or otherwise operated and which has either a quick action or a delayed action and which is adiustable so that the conditionto which it will respond may be predetermined.

Further objects are to provide a circuit breaker which has a heavy contact pressure when it is closed, in which this heavy contact pressure is maintained during the operation of the circuit breaker until the instant at which the contacts are suddenly separated, thereby avoiding burning of the contacts under overload conditions.

Further objects are to provide a circuit breaker in which the mechanism is so arranged that it is easy to operate in' opening and closing the circuit breaker and in resetting the trip means, and which is so made that there is no great wear on the parts during the opening and closing of the circuit breaker or during the resetting of the trip means as the mechanism is so arranged that during resetting, for example, relatively small forces or pressures are exerted between the cooperating parts, thereby minimizing wear.

Further objects are to provide a circuit breaker in which the trip means is required to exert only a very small force in order to cause automatic operation, the relation of the parts insuring relatching without any chance of wedging or jamming either the trip mechanism as a whole or any portion of the latch means.

Further objects are to provide a circuit breaker which has main switch operating means for opening and closing the switch, which main switch operating means is carried by auxiliary switch operating means which latter is biased towards switch open position and is normally held against motion by condition responsive means so that upon the occurrence of a predetermined condition, the auxiliary switch operating means will move the main switch operating means to switch open position.

In greater detail, further objects are to provide a circuit breaker in which there is an auxiliary lever pivoted at a fixed point and Divotally supporting a main lever intermediate the ends of the main lever, the auxiliary lever being held in its normal position by toggle link mechanism biased towards collapsing motion and when collapsed adapted to move the auxiliary and main levers to switch open position, the toggle link mechanism being normally held in its extended position by condition responsive means, and to provide main operating means connected by quick motion mechanism with the main lever and arranged to normally rock the main lever about its pivot point while the auxiliary lever is held in its normal position, and which is so organized that when the 1 main operating means is moved to switch open position, it will reset the toggle link mechanism in the event the toggle link mechanism has collapsed as a result of the occurrence of a predetermined condition.

Further objects are to provide a circuit breaker construction which is sturdy and is reliable in operation, which may be installed in a transformer case and submerged in the oil in the transformer case if desired, and which if a thermostatic trip means is employed, may be arranged to have the vthermostatic means respond solely to the heat generated by current passing through the thermostatic means or to the combined action of the heat in the oil fromthe transformer or other device as well as from the heat due to the current passing through the thermostatic means, or may be arranged to respond solely to the heat of the oil.

Embodiments of the invention are shown in the accompanying drawings, in which:

Figure 1 is a sectional view showing the circuit breaker in closed position, such section corresponding approximately to a section on the line l--l of Figure 2.

Figure 2 is a plan view of the structure shown in Figure l with parts broken away.

Figure 3' i a sectional view corresponding to latch an is pivoted as indicated at a: and is biased towards clockwise motion by means of a Figure 1 showing the circuit breaker after it has been manually opened.

Figure 4 is a sectional view approximately on the line 4--4 of Figured.

Figure 5 is a sectional view corresponding to Figure 1 showing the circuit breaker after it has been automatically opened.

Figure 6 is a sectional view on the line 8-6 of Figure 1.

Figure '7 is a fragmentary sectional view showing the circuit breaker mounted within a trans-. former casing.

Figure 8 is a sectional view on the line 8-4 of Figure 7.

Figure 9 shows a further manner'of mounting the circuit breaker. v

Figure 10 is a wiring diagram.

Figure 11 shows a further form of condition rcsponsive means.

Before proceeding with the detailed description of this invention it is to be understood that the circuit breaker may have either a single switch means, or a plurality of switch means, a circuit breaker with a single switch means having been chosen for the sake of illustration.

Referring to the drawings it will be seen that the circuit breaker is provided with a base i of insulating material from which a pair of insulating side walls 2 extend. These side walls may be joined b a transverse web 3.

The stationary contact 4 is supported from the web 3 and is carried bya relatively heavy conducting spring member 5 and is electrically joined to the terminal 6. The movable contact is indicated at 1 and is joined by means oi a flexible leader 8 to one leg of a U-shaped bimetallic thermostatic member 9, the other leg of which is joined to the terminal l0,see Figure 4.

Main switch operating means in the form of a channel like member H is provided. It carries the movable contact 1 at one end and is provided with a pair of slots l2 adjacent its other end. The circuit. breaker has an auxiliary switch operating means l3 also of channel shape which is pivotally joined to the main switch operating means H by a first pivot, or main pivot l4. The

auxiliary switch operating means I3 is pivoted to the side frames by means of a second pivot, or auxiliary pivot l5.

Normally the first pivot I4 is held in a fixed position by holding means composed of the toggle link mechanism having a pair of links l8 pivoted by means of a pin H to a pair of links IS. The links it are integrally joined by means of a transverse web I8 and are pivoted on the pivot pin l9. such pivot pin being carried by the side walls 2. One of the links is provided with an outwardly extending arm 20 so that the lower portion of the toggle mechanism is formed in the manner of a bell crank lever. The outer end of the arm 20 is normally latched beneath the latch 2! of the condition responsive means. The

. links of the actuator 28 are joined b means or a pin 30 which is provided with rollers 8|, see Figure 6, which ride within the slots l2 of the main switch operating means ll.

Main operating means in the form of a pair of levers 32 are positioned on the outer side 01' the walls 2 of the body portion of the circuit breaker and are pivoted at their inner ends on the pivot pins 33. They are Joined at their outer ends by means of the pivot pin 34 and a spring 35 extends between the pivot pins 30 and 34. It is to be noted that a second spring is provided which is indicated by the reference character It and extends between the pivot pins l4 and I! and bears against the pivot pin H in a manner tending to break the toggle formed of the links I8 and H by urging the knee ot the toggle towards right-hand motion as viewed in Figure l. The springs 35 and 38 are always under tension and the spring 35 is more powerful than the spring 36,

The circuit breaker is manually opened and closed by rocking the main operating means 22 back and forth between the full and dotted line positions shown in Figure 1.

Any suitable means may be provided for rocking the main operating means 32. For example the levers 32 forming the main operating means .Stop means such as the pins 44, see Figure 1,

may be provided for directly limitingthe swinging motion of the main operating means 22 when rocked in a left-hand direction as viewed in Figure 1. If desired stop means in the form of pins 45 may be provided for limiting the right-hand swinging motion of the main operating means as shown in Figure 3.

The operation of the circuit breaker is as follows: When it is desired to manuallyopen the circuit. breaker, the main operating means 32 is ,xrocked to the right from its full line position shown in Figure 1 to the position shown in Figure 3. During this rocking motion the line of pull of the spring 35 passes to the right or the pivot point 29 of the actuator 28 and such actuator is caused to suddenly move to the full line position shown in Figure 3, thereby opening the circuit breaker with a quick motion. When it is desired to close the circuit breaker, the main operating means 32 is rocked from the position shown in Figure 3 to the position shown in Figthe line of pull of ure 1. During this motion,

the spring I! crosses to the left of the pivot point 28 and consequently the actuator is suddenly rocked to the position shown in Figure 1, thereby closing the circuit :breaker with a quick motion. It is tobe noted from comparing Figures 1 and 3 that when the circuit breaker is closed, the heavy spring I supporting the stationary contact 4 is slightly compressed. It is to be noted also from reference to Figure 1 that when the circuit, breaker is in closed position, the mainswitch operating means I I nests within and rests upon the bottom portion of the channel, shaped auxiliary switch operating means l3, It is to be noted from Figure 3 that the opening motion of the main switch operating member II is arrested at the position shown invFigure 3 by the engagement of the transverse web of the channel-shaped main-switch operating means H with the actuator 28.

The first pivot H is normally held in a fixed position. However, as stated the spring 36 tends to break the toggle link mechanism formed of the links it and I8. When an overload occurs and the bi-metallic thermostatic member 9 warps downwardly, as a result of the current flowing therethrough, as shown in Figure 5, the latching lever 2| is moved in a counterclockwise direction and releases the arm 20 of the links it. This allows the toggle mechanism formed of the links I6 and I8 to collapse to the position shown in Figure and suddenly lowers the first pivot point I! as this toggle link mechanism forms the holding means or supporting means for the auxiliary switch operating means l3 which in turn supports the main switch operating means ll. During automatic operation as described hereinabove, it will be seen that the circuit breaker is opened with a quick motion.

When it is desired to reset the circuit breaker, the main operating means 32 is rocked from the position shown in Figure 5 to the position shown in Figure 3. The spring 36 pulls upwardly and this upward pull is transmitted both to the main switch operating means II and to the auxiliary switch operating means I3, thus raising both-of such members and also causing-the main switch operating means to rock with reference to the auxiliary switch operating means from the position shown in Figure 5 to the position shown in Figure 3. In addition to this, a pair of fingers 48 formed integrally with the main switch operating means H engages the links I6 and also assists in resetting the toggle link mechanism or holding means. The outer end-of the arm 20 and the upper face of the latch lever 2| are'provided with cam-shaped bevelled surfaces so as to rock the latch lever in a counterclockwise direction until the latch lever latches the arm .20 and thus latches the holding toggle mechanism in position. If, however, the thermostatic member 9 has'not cooled sufliclently, the latch lever 2| will be held in releasing position and no binding of any of the parts can occur even if it is attempted to reset the circuit breaker. After the circuit breaker has been reset, it is closed by rocking the main operating'means 32 from the position shown in Figure 3 to the position shown in Figure'l.

It is to be noted that heavy contact pressure is obtained by this circuit breaker and that the circuit breaker executes a quick opening stroke when it is either manually or automatically opened and executes a quick closing stroke when it is manually closed. It is to be noted also that when the circuit breaker is in closed position,

else slightly to the left. ,It has been shown directly below inFigure 1. Also it is to be noted that when the toggle link mechanism is set, the three pivot pins I4, I! and it are either directly in alignment or the, pivot pin I1 is slightly to the left of a line joining the pivot pins I4 and i9, such pivot pins being shown directly in alignment inFigure l.

The circuit breaker may be mounted in any suitable manner. As described hereinabove, it may be mounted within the transformer casing 4| and supported directly from the transformer 40. It may also be mounted below the oil level which is indicated at 4'! in Figure 7. Under these conditions the thermostatic member may be heated not only by the current passing therethrough but also by the general heat of the oil. The purpose of this is to allow the thermostatic element to respond not only to a relatively sudden overload but to allow it to respond to the gradual rise of temperature of the oil which would result from a small and prolonged overload due to the heating of the transformer itself. Thus there may be afiorded the double protection or opening the circuit breaker under the influence of an overload of reasonable magnitude or the opening of the circuit breaker from a prolonged small overload due to the heating of the transformer. It is obvious also that if desired the main current need not pass through the thermal member and the thermal member could then respond merely to the heat of the oil or the oil level could beso regulated that it is below the thermal member and then the thermal member would respond merely to the heat of the current passing therethrough.

As stated, the circuit breaker can be mounted in any suitable manner. For example, it may be arranged for wall mountin and may be positioned within the casing 48, which casing may have a rounded slotted top through which an insulating handle 49 projects, such handle being directly joined to the main operating means .32

corresponding to the main operating means 32 hereinbefore described.

Referring to the wiring diagram of Figure 10,

'it will be seen that the circuit breaker is mounted in series with the secondary 50 of the transformer 40.

Other iorms of condition responsive means could be employed. For example as shown in Figure 11 a solenoid type of condition responsive means has been illustrated and comprises the solenoid 5| which is adapted to raise the plunger 52 androck the lever 53. The lever 53 is provided with an adjusting screw 54 which has an insulating pin 55 adapted to bear against the arm 24 of the latch lever 2| heretofore described.

Any suitable time delay means may be provided. For example, the plunger 52 may be provided with a piston 56 which is mounted within the cylinder 51, such cylinder being provided with apertures for the flow of fluid. A suitable spring 58 is provided for returning the plunger to its lowest position.

It is apparent that the value of the conditio to which the circuit breaker may respond may be determined by thesetting of the adjusting screw 26 of Figure 1 or 54 of Figure 11.

The purpose of the time delay means as shown for instance in Figure 1-1 is to prevent the circuit breaker from suddenly openin for any sudden or extremely transitory overload for instance, but to allow the circuit breaker to open as promptly the pin 30 is. either directly below the pin 29 or as desired for an overload for a period longer than that for which the circuit breaker is designed.

Other time delay means could, of course, be employed and it is to be distinctly understood that the circuit breaker could be made to respond to over or under voltage, overload, phase reversal, or any other desired condition.

It is to be noted from reference to Figure 1 that by having the pivots of the toggle link holding means in alignment, no force due to the heavy contact pressure is transmitted to the latching means of the condition responsive means and consequently very little friction is produced which has to be overcome by the condition responsive means.

It will be seen that a circuit breaker has been provided by this invention which has toggle means which constitute holding means for supporting a first or main pivot point and that main switch operating means is pivotally joined at this first pivot point to auxiliary switch operating means, which latter is pivoted at a second or auxiliary pivot point. 'It will be seen further that the actuator which is operated as a quick motion means from the main operating means is so arranged that it locks the circuit breaker in closed position with a heavy contact pressure and yet can be easily operated from the main operating means 32. It is to be noted also that the holding means normally holds the first pivot in its up position and this first pivot is, therefore, substantially a stationary point about which the main switch operatin means rocks when it is manually opened and closed, this first pivot point being suddenly lowered on automatic operation and the main and auxiliary switch operating means rocking about the second or fixed pivot point, the

main switch operating means slightly rocking about the first pivot point though this latter action is not strictly necessary and depends upon the extent to which the first pivot point is lowered during automatic operation. As shown in Figure 5 the lever 20 is adapted to engage the lower side of the auxiliary switch operating means l3 and to thus constitute a stop to limit the collapse of the toggle formed by the links it and I8.

It is to be understood that reference to an up or down direction or to raising or lowering parts of the device are not intended as limiting expressions as obviously the circuit breaker could be mounted in any position desired.

The circuit breaker chosen for illustration is a single switch unit type but obviously, as hereinbefore stated, the circuit breaker may be either a, single or multiple switch type without departing from the spirit of this invention.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

. I claim:

1. A circuit breaker comprising stationary contact means, movable contact means, a main switch operating means for moving said movable contact means into and out of engagement with said stationary contact means, an auxiliary switch operating means pivoted to said main switch operating means at a first pivot and pivotally supported at a second pivot, main operating means for moving said main switch operating means about said first pivot to open and close said circuit breaker, holding means in the form of toggle links for normally holding said first pivot against motion and releasable to allow said main and auxiliary switch operating means to move to switch open position, and condition responsive iiieans for releasing said holding means.

2. A circuit breaker comprising stationary contact means, movable contact means; a main switch operating means for moving said movable contact means into and out of engagement with said stationary contact means, an auxiliary switch operating means pivoted to said main switch operating means at a first pivot and pivotally supported at a second pivot, holding means in the form of toggle links for normally holding said first pivot against motion and releasable to allow said main and auxiliary switch operating means to move to switch open position, condition responsive means for releasing said holding means, and main operating means for moving said main switch operating means about said first pivot to open and close said circuit-breaker without motion of said auxiliary switch operating means.

3. A circuit breaker comprising stationary contact means, movable contact means, a main switch operating means for moving said movable contact means into and out of engagement with. 'said stationary contact means, an auxiliary switch operating means pivoted to said main switch operating means at a first pivot and pivotally supported at a fixed pivot, main operating means for moving said main switch operating means about said first pivot to open and close said circuit breaker, holding means in the form of normally fully extended toggle link mechanism for normally holding said first pivot against motion and releasable to allow said main and auxiliary switch operating means to move about said fixed pivot to switch open position, and condition responsive means for releasing said holding means.

4. A circuit breaker comprising a stationary contact, a movable contact, a main switch operating means consisting of a main lever operative ly connected to said movable contact, an auxiliary switch operating means consisting 01' an auxiliary lever pivoted at a fixed point and pivotally supporting .said main leverintermediate the ends of said main lever, condition responsive means including latch means, supporting means normally restrained by said latch means for normally holding said auxiliary lever against motion and I releasable upon the occurrence of a predetermined condition to move said auxiliary lever to carry said main lever to switch open position, and quick'motion means for rocking said main lever to switch open and switch closed position without causing motion of said auxiliary lever.

5. A circuit breaker comprising a stationary contact, a movable contact, a main switch operating means consisting of a. main lever operatively connected to said movable contact, an auxiliary switch operating means consisting of an auxiliary lever pivoted at a fixed point and pivotally supporting said main lever intermediate the ends of said main lever, condition responsive means including latch means, supporting means normally restrained by said latch means for normally holding said auxiliary lever against motion and releasable upon the occurrence of a predetermined condition to move said auxiliary lever to carry said main lever to switch open position, and quick motion means for rocking said main lever to switch open and switch closed position.

6. A circuit breaker comprising a stationary contact, a movable contact, a main switch operating means consisting of a main lever operatively connected to said movable contact, an auxiliary switch operating means consisting of an auxiliary lever pivoted at a fixed point and pivotally supporting said main lever intermediate the ends of said main lever, condition responsive means including supporting means for normally holding said auxiliary lever against motion and releasable upon the occurrence of a predetermined condition to move said auxiliary lever to carry said main lever to switch open position, and quick motion means for rocking said main lever to switch open and switch closed position, said quick motion means when moved to switch open position following the occurrence of said predetermined condition'acting to restore said auxiliary lever to its initial position.

7. A circuit breaker comprising a stationary contact, a movable contact, a main switch operating means consisting of a main lever operatively connected to said movable contact, an auxiliary switch operating means consisting of an auxiliary lever pivoted at a fixed point and pivotally supporting said main lever intermediate the ends of said main lever, condition responsive means including supporting means for normally holding said auxiliary lever against motion and releasable upon the occurrence of a predetermined condition to move said auxiliary lever to carry caid main lever to switch open position, and quick motion means for rocking said main lever to switch open and switch closed position, said quick motion means including spring means movable to a position to restore said auxiliary lever to its initial position after the occurrence of said predetermined condition.

8. A circuit breaker comprising an auxiliary lever pivoted at a fixed point, a main lever pivoted to said auxiliary lever intermediate the ends of said main lever, a stationary contact, a movable contact operatively connected to said main lever, toggle mechanism normally supporting said auxiliary lever against motion and biased in a direction to move said auxiliary and main levers towards switch open position, condition responsive means controlling the action of said toggle Inechanism, manually operable means for normally rocking said main lever to switch open and switch closed position and including a spring operated actuator acting on said main lever, said main lever having means adapted to engage said toggle mechanism to mov said toggle mechanism back to its initial position after the occurrence of a predetermined condition to reset said toggle mechanism.

9. A circuit breaker comprising an auxiliary lever pivoted at a fixed point, a main lever pivoted to said auxiliary lever intermediate the ends of said main lever, a stationary contact, a movable contact operatively connected to said main lever, toggle mechanism normally supporting said auxiliary lever against motion, a first spring means biasing said toggle mechanism towards collapsing motion to move said main and auxiliary levers towards switch open position, condition responsive means controlling the action of said toggle mechanism and releasing said toggle mechanism for collapsing motion upon the occurrence of a predetermined condition, and manually operable means for normally rocking said main lever to switch open and switch closed position and including a second spring means, said second spring means being more powerful than said first spring means, said manually operable means when rocked to switch open position after said toggle mechanism has collapsed carrying said second spring means to a position to overpower said first spring means and restore said toggle mechanism to its initial position.

EDWIN A. LINK.

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