US2070305A - Circuit interrupter - Google Patents

Description

Fell 9 1937 o. s. JENNINGS y CIRCUIT INTERRUPTER v Original Filed Jan. 5, 1934 3 Sheets-Sheet 1 Feb. 9, 1937. o. s. JENNINGS 2,070,305

CIRCUIT INTERRUPTER 0 3 Sheets-Sheet 2 Original Filed Jan. 5, 1954 i /7 mm INVENTOR @mf/am" Feb- 9, 1937# o. s. JENNlNGs CIRCUIT INTERRUPTER Original Filed Jan. 3, 1934 3 Sheets-Sheet 3 Patented Feb. 9, 1937 CIRCUIT INTEBRUPTER Oliver 8. Jennings, Mansfield, Ohio. assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Appunti@ .mmm s. 1934, serai No. 105,011

Renewed my 11, 193s 31 Claims. (Cl. ZOO-116) My invention relates generally to electrical apparatus of the type wherein a sequence of operations takes place automatically following the occurrence of predetermined conditions. More specifically, my invention relates to circuit interrupters of the so-called automatically reclosing type and is an improvement on the device of my application Serial No. 712,577, filed February 23, 1934, to make it reclose automatically.

Circuit lnterrupters of this type usually comprise a contact means, normally held in the open or the\c1osed circuit position by a suitable biasing means, and means operable upon the occurrence of overloads or other conditions to cause the contact means to move from one position to the other position, to stay in the other position for a predetermined period of time, and then to return, automatically, to the original position. In the past, these breakers have been used quite extensively for controlling low voltage, moderate power circuits, such as those used with heating apparatus, signal and alarm systems, and the l'ke. In recent years, however, it has been found desirable to utilize automatically reclosing breakers with high voltage apparatus which may be connected in systems or networks having considerable available power.

For these applications, the previously known devices have proven quite unsatisfactory. Their interrupting capacity is usually limited, particularly on highly inductive circuits; few of these breakers positively open the circuit with a snap action of the moving contacts; practically none f the devices are capable of distinguishing between large and moderate current overloads; and in addition substantially all of the previously 'known devices are costly to manufacture. It is an object of my invention, therefore, to provide an improved automatically reclosing circuit in terrupter that shall be capable of positively interrupting large amounts of power, that shall actuate the contact means with a snap action in both directions of motion, and that shall be simple in structure and inexpensive to manufacture.

Another object of my invention is toprovide an improved automatically reclosing circuit breaker that shall utilize the minimumpossible number of parts and that shall be as nearly foolproof as is possible.

A further object of my invention is to provide an improved automatically* reclosing circuit breaker that shall include means for causing the actuation of the circuit breaker substantially instantaneously upon the occurrence of predetermined conditions, and after a predetermined time delay upon the occurrence of other predetermined conditions.

A still further object of my invention is to provide an improved circuit breaker that shall .3 include means operable in response to the movement of a handle member to cause the actuation of the interrupter, that shall include actuating means for causing the interrupter to operate as an automatically reclosing breaker, and that l0 shall include means for selecting one or the other of the two actuating means.

An ancillary object of my invention is to provide a manually operable, trip-free circuit breaker that shall include selective means actul5 able to cause the breaker to operate as an automatically reclosing device.

These and other objects of my invention will be made more apparent by reference to the following drawings and description of two preferred 2o embodiments of my invention. The rst of these preferred embodiments is a circuit breaker of the automatically reclosing type. and the second is a circuit breaker which includes means selective to cause the actuation of the contacts either in response to movement of the operating handle or through the operation of automatic reclosing means.

Figure 1 is a plan view of a single pole, double break circuit interrupter of the automatically reclosing type, wherein are embodied the principal features of applicants invention; the cover has been removed to more clearly illustrate the various structural elements.

Figs. 2 to 6, inclusive, are sectional views on 35 the line II'-II of Fig. l, and show the moving parts of the circuit breaker illustrated in Fig. 1 in various positions assumed during the operation of the device.

Fig. 7 is a fragmentary view showing the lde- 4o tails of the means used for supporting the switch members of both modifications of applicants lnvention.

Fig. 8 is a fragmentary view of a single pole double break circuit interrupter which includes means responsive to the movement of an operating handle for causing the actuation of the oontacts, and which also includes automatic means for causing the interrupter to operate as an automatically reclosing device. The view is taken on the line VIII-VIII of Fig. 9.

Figs. 9, 10 and 1i are sectional views on the line IX-IX of Fig. 8 and show the moving parts of the circuit interrupter illustrated in that figure in various positions, and

UJI

4tral portion of the loop (Fig. 7).

Fig. 12 is a sectional view showing a circuit interrupter embodyingthe features oi' my invention in use with a transformer, the entire interrupter structure being positioned within the transformer tank beneath the normal level of the cooling liquid disposed therein.

The automatically reclosing circuit breaker illustrated in Figs. .l to 6, inclusive,A includes a pair of looped switch arms 3, preferably of bimetallic material, which are mechanically connected to each other at one end by a suitable tie link 5, and which include contact means 'i supported at the other end; means for pivotally supporting the assemblage formed by the two interconnected switch arms 3; a pivotally supported actuating member 9 movable between two positions; a spring means Ii for operatively connecting the assemblage of switch arms Aand the actuating member; and a pair of stationary contacts I3 for cooperating with the moving contacts i to open and to close the circuit. In the illustratedembodiment, the cooperating contacts are normally held in the circuit closed position. Upon the occurrence of predetermined conditions, the -bimetallic switch arms 3 are adapted to cause suiiicient relativev movement between the line of action ofthe over-center spring il, which connects the switch arms 3 and the actuating member S, and the vpivot points of the actuating meinber and the switch arms to cause the contacts to be moved to the open circuit position. The

contacts then remain in this `position for a predetermined period of time, following which the interrupter is automatically restored to the closed circuit position. The pivot points oi the assemblage of switch members and the actuating member are spaced from each other in such manner that the contacts are moved to both the circuit closed position and to the open circuit position with a snap action.

, The various parts of the circuit breaker are mounted upon a base I5 which is preferably o molded insulating material, and, ii" desired,7 a cover Ii such as that shown in Fig. 2 may be provided for enclosing 'the movingparts of the device. The' cover is likewise preferably of molded insulating material. Two strips of conducting material IS are supported on the base i5 by means of screws 2 i. A portion of each of these conducting strips I 9 extends through the upstanding side portion 23 of the base member I 5 in order to provide terminals for the breaker, suitable screws 25 being provided for connecting the line conductors thereto. One of the stationary contacts I3 is aiiixedto the other end of each of these conducting strips I9, in order to cooperate with the similarly proportioned contact affixed to one end of each of the bimetallic switch arms 3.

Each of the bimetallic switch arms 3 comprises a substantially flat strip of bimetallic material which is looped back upon itself, and which is provided with a pivot pin 21 affixed to the cen- The ends of each ofthe two looped switch members opposite to the ends whereon the contacts l are supported are electrically and mechanically connected by means of the tie member 5, which lcomprises a iiat strip of conducting material riveted thereto by two rivets 29.

The inter-connected switchvarms 3 are adapted to be pivotally supported upon two upstanding members 3I of insulating material each of which is provided with a suitablevbearing portion 33 (Fig. 7) for engaging one of the pivot pins 21 aifixed to the central portion of each of the looped switch arms 3. Each of these upstanding members 3l engages a suitable reces 35 in the base I 5 of the circuit breaker and is adapted to be retained therein by means such as the screws Il. A U-shaped support member 33, which is likewise afiixed to the base I 5 by means of suitable screws 4 I is provided for supporting the actuating member 9, two pivot pins d3 being provided for engaging the two bearing portions of that member. v

The actuating member 9 is substantially U- shaped and the portion 4l which connects the two side portions of the U is provided with an opening 49 for engaging one end of the overcenter spring I i. In order to facilitate the operation of the interrupter, the portion of the actuating member which directly engages the spring Ii is preferably formed as is shown in Figs.-2 to 6 with a knife edge 5i. 'Ihe other end of the overcenter operating spring il is adapted to engage a suitable opening 53' (Fig. l) and similar knife edge (not shown) provided in the tie member 5 which connects the two pivoted switch arms 3. A bracket member 55, which is fastened to the base i5 by suitable means (not shown), is provided or Ydening the limits of motion of the actuating member 9, these limits being adjustable by means of the set screws 5l and 5S and their associated nuts 6i.

clockwise direction about their pivot point 63 is defined by the engagement of the moving con-V tacts l with the stationary contacts i3, and the movement of the switch arms S in a clockwise direction is deiined bythe engagement of the upper side oi the contact end of each of those The limit of motion of Y the interconnected switch arms 3 in a countermembers with the projection 55 that extends outassociated looped switch arm thence through Athe tie member 5 which connects one end oi each f oi the looped switch members, the other loomd switch member 3 and its associated contact l to the secondary stationary contact i3, and thence through the second conducting strip i?) to the other terminal portion. It will be noted, as is shown particularly in Fig. l, that the space between the two switch members is entirely clear in order to permit free motion of the overcenter operating spring II therebetween.

The circuit breaker is shown in the closed circuit position in Fig. 2. Upon the occurrence of an overload condition, of Vsuilicient magnitude and duration to cause appreciable heating of the bimetallic switch arms 3, those members begin to move the tie member 5 in a direction away from the base I5 of the interrupter. So long as this movement docs not bring the line of action Iof the overcenter spring (indicated by the line actuating member 9 in a counterclockwise direction about its pivot point 69. This component of force causes the actuating member 9 to move from the position shown in full in Fig. 4 to the position indicated by the dotted lines in that figure. The movement once initiated takes place with a progressively increasing acceleration due to the fact that any movement of the actuating member 9 from the lower position toward the upper position results in a progressive increase in the component of force tending to produce that movement.

When the actuating member moves. as described above, from the lower position to the extreme upper position, the line of action of the overcenter spring Il is moved from the position indicated by the line 61 in Fig. 4 to the position indicated by the line 68. That is, the line of action of the spring Il is moved above the pivot point 63 of the inter-connected switch members 3 thereby producing a component of force tending to move those members in a clockwise direction about their pivot. This results in the immediate movement of the switch members from the closed-circuit position to the open-circuit position (illustrated in Fig. 5) where it will be noticed that the overcenter spring l I exerts a component of force biasing both the actuating member 9 and the interconnected switch members 3 to the position shown.

If the circuit opening producing movement of the bimetallic switch arms 3 has been caused by the flow therethrough of overload currents, the opening of the interruptor will immediately cause the interruption of the controlled circuit, and the switch arms will begin to cool and return to their normal cooled position (Fig. 2). The cooling of the bitmetallic switch members 3 moves the tie member 5 and with it` the line of action of the overcenter spring Il from the position indicated by the line 10 in Fig. 5 to the position indicated by the line 12 in Fig. 6. In this position, the overcenter spring Il exerts a component of force tending to move the interconnected switch members 3 in a counter-clockwise direction about their pivot point 63, and since there is no force opposing this component, the breaker is again in an unstable position and the interconnected switch arms 3 will begin to move toward the closed circuit position. This movement will take place with a progressively increasing acceleration, exactly similar to that accompanying the opening movement of the actuating member 9 and the switch members, due to the fact that any additional movement of the switch members results in a progressive increase in the component of force tending td produce that movement. Thus, the interconnected switch members move to the closed circuit position (shown by dottedl lines in Fig. 6) with a snap action. The movement of the switch members" 3 to the closed-circuit position causes the line of action of the overcenter spring Il to be brought to a position beneath the pivot point 69 of the actuating member, as is indicated by the line 14 in Fig. 6, thereby producing a component of force tending to mov'e the actuating member 9 in a clockwise direction about its pivot point. The ultimate result of this is to cause the actuating member to return to the position shown in Fig. 2.

Itwill be noted that during the operation of this embodiment of my invention the contacts of the circuit interrupter are held in the closed circuit position with a definite force up until the instant' that the line of action of the overcenter spring Il crosses the pivot point of the interconnected switch members 3. However, since this movement of the line of action across the pivot point of the switch members takes place at comparatively high speed, due to the rapid accelera-- tion previously imparted to the actuating member l, and due to the fact that the contact means immediately thereafter begin to move to the opencircuit position with a snap action, it is proper to state that the moving contacts are held in the clod circuit position up until the instant of contact separation with a dennite force.

In the above description of the operation of a preferred embodiment of my automatically reclosing circuit interrupter, it has been assumed that the movement of the bimetallic switch membersloccurredinresponsetointernalheating produced by the ow therethrough of overload current. It is quite possible, however, to cause automatic operation of the device to take place as a result of changes in the temperature of the medium surrounding the breaker. Thus, if the automatically recioslng circuit breaker is disposed within a transformer tank in such manner that.

the bimetailic switch arms are in contact with the oil used for insulating the transformer (as is shown in Pig. 12), the operation of the breaker might result from increases in the temperature of the oil which were produced by internal arcing due to localized insulation breakdown, or by prolonged small overloads, themselves not capable of causing sufficient internal heating ofthe bimetalof a large body of oil such as is found within a transformer tank will take place comparatively slowly. This arrangement is very desirable in that it permits the use of the transformer or like device up until the heating induced by the overload reaches a dangerous point, and after operation, it removes the transformer or other equipment from the circuit for a sufiicient period of time to assure the overload condition being brought to the attention of the proper parties.

I'he amount of movement of the tie member 5 necessary to cause the actuation of the breaker may be readily adjusted through the set screws 51 and 59 and their associated nuts 6| which together denne the limitations of motion of the pivoted actuating member 9. These adjusting screws permit the breaker to be calibrated over a reasonably wide range of current or temperature valves and in addition permit changes or adjustments in the calibration of the device to be readily made at any time.

The details of the method which I prefer to use for pivotally supporting the assemblage of switch arms is shown in detail in Fig. 7. The pivot pin 21, which is riveted or otherwise securely fastened to the closed portion of each of the looped switchyarms 3, is preferably formed of a'hard bearing material. The pivot pin 21 is, as discussed previously, adapted to engage the cooperating member 33 disposed in the upper portion of each ofI the support members 3|, a suitable threaded opening being provided therein. The cooperating member 33 comprises a substantially cylindrical means preferably -of hard material having a conical shaped recess 'Il therein for engaging the pointed end of the pivot hpir.. l

be in response to vmovement of the operating handle or shall be automatic.

Generally, this modiiied form of my invention comprises a base mi of molded insulating material having four upstanding side portions |193 integral therewith, a pair of looped switch mem bers i|l5 of bimetallic material each of which is provided with a movable contact |07 affixed to one end thereof, stationary contacts |09 for cooperating with the movingicontacts, a pivoted switch actuating member ki i i, an overcenter spring ||3 for operatively connecting the pivoted switch members |05 and the actuating member an operating handle H5, and a latch means H7 for holding the operatingr handle in one position so as to cause the interrupter to operate as an automatically reclosing breaker. The stationary contacts |09 and their associated conducting strips ii9 which form the terminals of the device are exactly similar to the conducting strips and contacts shown in the embodiment disclosed in Figs. i to 7. Likewise, the assemblage of switch members 05 and the support means therefor, which includes the two support members iEi are essentially the same as the similar members disclosed in the above described embodiment of my invention.

The actuating member ii i is likewise similar to the actuating member 9 described previously. It includes, however, an additional portion E23, which is adapted to be operatively engaged by the operating handle H5. This portion |23 is substantially Y shaped, as is shown in Fig. 8,

and is mechanicallyT connected to the side portions of the actuating member Hi by means of two rivets E25. pivotally supported, through the agency o two pivot pins 26 on a substantially Ueshaped frame member |21 which, in turn, is aiiixed io the base i by a pair of suitable screws |29.

` In addition to the pins |26 which are used for supporting the actuating member, a second pair of pivot pins 93| is supported on the U-shaped frame member. These pins |3| are adapted to pivotallyy support the bifurcated portion |33 of the operating handle |l5, as is shown particularly in the drawings.

The operating handle ||5, in addition to the bifurcated portion |33 which engages the pivot pins |32 is provided with a handle portion |35 of insulating material adapted to extend through va suitable opening |31 in the cover |04, and a pair of downwardly projecting portions |39 and |4| which are adapted to provide surfaces for cooperating with the end portion |43 of the member |23 affixed to the actuating member 'I'he` surfaces provided by these downwardly projecting portions |39 and |4| are spaced some distance from each other and thereby permit the actuating member to move independently of the operating handle once the mechanism of the interrupter has been set iny motion. This arrangement is of particular value in assuring the The actuating member Mi is opening and clomng of the circuit breaker contacts with a snap action, and adds much to the reliability of operation of the device.

A latching pin |45 (Fig. 8) extends outwardly from the upperslde portion |33 of the operating handle ||5. 'Ihis pin is adapted to cooperate with a pivotally `supported latching member |41, biased to the latched position by a suitable spring |49, to hold the operating handle in the closed circuit position. The latching memberI |41, in turn, is provided with a projecting member |5| of insulating material which extends through a slotted opening |53 in one of the upstanding side portions |03 of the base ||l|. This member 5i permits the latching member |41 to be moved so as to disengage the operating handle and permit manual operation of the interrupter.

The circuit breaker is shown in the normal open-circuit position in Fig. 9. To close the contacts, the operating handle H5 is moved from `the position shown in Fig. 9 to the position shown in Figs. l and 1l. This movement of the operat ing handle causes the downwardly projecting portions ISS and I Hand the actuating member IH to move from the position shown in full lines in Fig. 9 to the position shown in dotted lines in Fig. 9. It will be noted that theline of action of the over-center spring ||3 has thereby been moved from a position above the pivot point i? of the assemblageof switch members (indicated by the line i 55) to a position below that pivot point (indicated by the line |59, the interrupter is thus in an unstable position, mechanically, and the switch members |95 immediately begin to move to the closed circuit position with a constantly increasing acceleration; due to the fact that any movement of the switch members causes a progressive increase in the force producing that movement. a snap action, and in moving to the closed position, carry the line of action of the over-center spring H3 from the position indicated by the line H59 to the position indicated by the line iti, or, in other words, carry the line of action beneath the pivot point |63 of the actuating member i i i. The result of this is to cause the actuating men1- ber i i i to likewise move to the fully closed position (Fig. l0), independently of the yoperating handle iid. v

The spacing of the surfaces provided by the downwardly projecting portions |39 and |4| is such that once the actuating member has been moved to a position where the closing op. eration begins (that is, to a position where the portion |43 of the actuating member disengages the downwardly projecting'pcrtion |39 which initiated the movement) that member is free to move, independently of the operating handle to the closed circuit position, 'in' which position the actuating member is completely disengaged from the operating handle ||5, as is shown in Fig. iii.

In the above description of the operation of the breaker, the movement of the assemblage of switch members to the closed circuit position and the movement of the actuating member from The contacts are thus closed with the position shown in dotted lines in Fig. 9 to the is moved to the closed-circuit position, 1t is 75` latched-in through the engagement of the alot III in the latching member |41 with the pin |45 aflixed to one oi' the side portions |33 ot the handle. It it is. desired to manually open the circuit controlled by the interrupter, the latching member |41 is lifted and the handle is moved in a counter-clockwise direction from the position shown in Fig. 10. During this movement, the downwardly'projecting portion |4| engages the portion |43 of the member |23 rigidly ailixed to the actuating member land moves that member a suillcient distance to'cause the line of action of the overcenter spring ||3 to move above the pivot point of the actuating member, the center of the pin |26. 'Ihe portion |43 of the actuating member then disengages the downwardly projecting portion |4| and moves automatically, under the biasing action oi the overcenter spring ||3 to the position shown in Fig. 9. In moving to this position, the line of action of the overcenter spring |3 is carried across the pivot point |51 of switch member |05 and those members likewise move to the open circuit position, as shown in Fig. 9, with a snap action. The fact that the line of action of the over-center spring ||3 has been carried across the pivot point |51 of the switch member causes the switch member to remain in its open-circuit position until the handle is moved to closed-circuit position. This is the case even though, as described later, the interrupter is made to automatically return to closed-circuit position when opened in response to an over-load.

When the circuit breaker is in the position shown in Fig. 10, in which position the handle is held against motion in either direction by the latch member |41, and an overload, or increase in the temperature of the ambient medium occurs, the bimetallic switch arms 'lli expand in such manner that the tie member |61\is moved away from the base ||I| of the circuit breaker. It the overload or increase in ambient temperature is of suillcient magnitude and duration to cause the tie member |81 to be moved -from the Y position shown in i'ull lines in Fig. l0 to a position substantially coinciding with that shown in dotted lines in Fig. 10, the line of action of the overcenter spring ||3 will be carried across the pivot point of the actuating member III (that is, from the position indicated by the line |63 to the position indicated by the line |1|) and the spring will exert a component biasing that member in a counter-clockwise direction. The immediate result is to cause the actuating member to move from the position shown in Fig. 10 to the position shown in Fig. l1, the limit oi the counterclockwise motion being dened by the engagement of the portion |43 of the actuating member with the downwardly projecting member |33 which comprises a part'oi the operating handle H5. As the actuating member moves about 4its pivot point, the line of action of the overcenter spring is carried above the pivot point of the assemblage of switch members (that is,'from the positioned indicated by the line |1| to the position indicated by the line |13) thereby causing those members to be moved from the closed circuit position (Fig. 10) to the open circuit position (Fig. l1) with a snap action. The various elements of the interrupter are then in the position shown in Fig. 1l.

As the bimetallic switch arms cool, either due to the interruption of an overloadcurrent ilowing therethrough, or because of changes in the ambent temperature, the tie member |31, and with it the line oi action of the overcenter spring. is moved from the position shown in full lines in Pig. 11 to the pomtion shown in dotted lines in Fig. 11. In this latter position, the assemblage oi' switch members is biased to the closed circuit position, and, of course, begins to move immediately to that position. As this movement progresses, the line oi' action of the overcenter spring ||3 is carried beneath the pivot point of the actuating member and that member disengages the operating handle and moves automatically back to the position shown in Fig. 10. 'I'he breaker thus operates as an automatically reclosing breaker when the handle H5 is latched in the closedcircuit position. A

Both the opening and closing operations once initiated take place substantially instantaneously, thus the contacts are held in the closed circuit position by a definite force up until the final stages of the circuit opening operation and are then moved from the closed position to the open circuit position with a snap action. Likewise, the contacts are closed with a snap action and once they have engaged, are held in such engagement with a very appreciable force, comparable in magnitude to the normal contact pressure securing force. Through this arrangement, I have made possible a thermally responsive circuit breaker which is capable of carrying reasonably high currents, and which is capable of interrupting very considerable amounts oi power.

'I'he downwardly projecting portions |38 and |4| which provide opposed surfaces for engaging the actuating member comprise in effect a lost motion connection between the operating handle ||5 and the actuating member Thus, even though the handle ||5 is held in the closed-circuit position, manually or through the agency of the latching means ||1, the breaker will open automatically upon the occurrence of overload or other conditions. The interrupter may be said, therefore, to be entirely trip free oi' the operating handle.

One feature oi' my invention which is common to both embodiments of my invention and which has not previously been discussed, is the arrangement of the looped switch arms (3 and |05) and the eilect thereon of the magnetic reactions resulting from the ilow therethrough of heavy overload currents. It will be noted, as is shown particularly in the drawings, that the current path through both of these members is, by virtue of their looped construction, substantially in opposite directions. Thus, when very heavy overload currents ilow therethrough the magnetic repulsion existing between the opposed side portions oi the switch arms may be sulcient to move the time member to a position where automatic operation of the breaker will be caused to take place. In the automatic reclosing breaker, this arrangement gives added protection to the connected equipment due to the -iact that the breaker will open substantially instantaneously upon the occurrence oi' transient overloads o! very large magnitude, thus limiting the current flow in the protected equipment and preventing damage thereto, and yet at the same time will reclose resiliency of the switch members themselv and v thus is not readily adjustable when the design has been decided upon. However, it rarely occurs that much flexibility in this regard is either desired or necessary, because overloads upon whic instantaneous operation is desired are ordinarily of a magnitude many times the maximum safe overload that the protected device can carry for any appreciable length of time.

From the above, it will be seen that I have disclosed a new and improved automatic reclosing circuit interrupter which is simpler in design and more reliable in operation than the previously known devices of this type, which opens and closes the cooperating contacts with a snap action and which is responsive either to the current :dowing in the control circuit or to the temperature of the ambient medium.

In addition, I have disclosed an automatically recloslng breaker,4 having the above-described desirable characteristics, which include an operating handle manually or otherwise movable to eect operation of the breaker, and which includes selective means whereby the operation of the interruptor may be eected in response to movement of the operating handle or automatically as an automatically recloslng breaker. Furthermore, the automatically reclosing breaker, according to my invention is entirely trip free of the operating handle and is as substantially fool proof in operationr as is known in the art at the present time.

While, in accordance with the patent statutes, I have disclosed the details of two preferred embodiments of my invention, itis to be understood that many of the details disclosed are merely illustrated and that variations in their precise form will be both necessary and desirable in certain applications. I desire, therefore, that `the language of the accompanying claims shall be accorded the broadest reasonable construction and that my invention shall be limited only by what is expressly stated therein and by the prior art.

I claim as my invention:

1. In a thermostatic device, a member having at least a portion thereof of thermally responsive material, one end of said mem r being movable between two extreme positions the operation of said device, means for pivotally supporting said member intermediate its ends, the other end of said member being movable, upon the occurrence of predetermined conditions, without moving said first-mentioned end to actuate said de-` vice, and means operablein responseto the movement of said other end to cause said iirst-mentioned end to move from one extreme position to the other with a snap action and to automatically return to its original position.

, 2. In a thermostatic device, a member having atl least a portion thereof of thermally responsive material, one end of said member being movable between two extreme positionsV during the operations of said device, meansfor pivotally supporting said member intermediate its ends, the other end of said member being movable, upon the occurrence of predetermined conditions, withmovable between two extreme positions in order that said contact means may be moved to an open-draait position and to a closed-circuit position, means for plvotally supporting said member intermediate its ends, the other end of said member being movable, upon the occurrence of predetermined conditions, without causing substantial movement o! said end upon which said con- 'l tact means is supported, and means operable in response to the movement of said other end to cause said contact supporting end to move said contact means from one position to the other and to automatically return said contact means to its original position upon the occurrence of apre- `determined condition.

4. In a circuit interrupter, a switch member comprising a hat strip of bimetallic material, contact means supported adjacent one end ci said member, said end being movable between two extreme positions to eiiect the movement of said contact means to the open-circuit and to the closed-circuit position, means for pivotally supporting said member intermediate `its ends, the other end of said member being movable, upon the occurrence of predetermined conditions, independently of said end upon which said contact means is supported, and means operable in response to the movement of said other end to cause said contact supporting end to move said contact means from one position to the other with a lsnap action `and to automatically return said contact means to its original position likewise with a snap action.

5. In a circuit interrupter, contact means movable between two extreme positions to open and to close the circuit, and operating means for causing said movable means to move from one extreme position to the other extreme position upon the occurrence of predetermined conditions, and to automatically return to the original position upon the occurrence of other predetermined conditions, said operating means including a pivoted contact actuating :member having at least a portion thereof of `thermally responsive material, and an overcenter springor moving said actuating member to the open-crcuit and to the closed-circuit position with a snap action, said portion of thermally responsive material being movable when heated to cause relative movement between the line of action of said spring and the pivot point of said actuating member.

6. In :a circuit interruptor, contact means movable between two extreme positions to open and to close the circuit, and operating means for causing said contact means to move from one extreme position to the other, withfa snap action, upon the occurrence of predetermined conditions, and to automatically return to the original position, likewisewith a snap action, upon the occurrence of other predetermined conditions, said operating means including a pivoted contact actuating mem ber having at least a portion thereof of bimetallic material, a second pvoted member, and an overlso members, said portion o! bimetallic material being movable upon the occurrence o!- predetermined conditions 'to cause suilcient relative movement between the line of action of said spring' and the pivot point o! said actuating member to eilect the actuation of said interrupter.

7. In a circuit interrupter, contact means movable between two extreme positions to open and to close the circuit, and operating means for causing said contact means to movefrom one extreme position to the other, with a snap action, upon the occurrence of predetermined conditions, and to automatically return to the original position, likewise with a snap action, upon the occurrence of other predetermined conditions, said operating means including a pivoitedl contact actuating member having at least a portion thereof of bimetallic material, a second member pivotally supported at a point spaced some distance from the point oi support of said actuating member. and an over-center spring means connectedat one end to each of said pivoted members, said portion o! bimetallic material being movable upon the occurrence of predetermined conditions to cause sufiicient relative movement between the line of action of said spring and the pivot points of said pivoted members to eiect the actuation of said interrupter.

8. In a circuit interrupter, contact means movable between two extreme positions to open and to close the circuit, and actuating means for said.-

contact means, said actuating means including an operating handle movable, through the application thereto of a suitable force, to cause said contact means to move from one position to the other,

and means automatically operable, independently able between two extreme positions to open and to close the circuit, and actuating means for said contact means, said actuating meansincluding an operating member movable, through the application thereto of a suitable force, to cause said contact means to move from one position to the other, automatic means operable upon the occurrence of predetermined conditions to cause said contact means to move from one position to the other and to automatically return to the original position after a time delay, and selective means for causing the operation of said interrupter to be in response to movement of said operating member or in response to the actuation of said automatic means.

l0. In a circuit interrupter, contact means movable to an open-circuit and 'to a closed-circuit po spective of the position of said handle means, and

means automatically operable to cause said interrupter to return to said first position, upon the occurrence of other predetermined conditions, following the operation of said electro-responsive means.

11. In a circuit interrupter. contact means movtact means to move from one position to the oth-' ableto anopen-circuitandtoaclosed-circuit position, and actuating' means 'for said contact means, said actuating means -including a handle meros-movable to causesaid contact means to move from one position to the other, electro-responsive means operable upon the occurrence oi predetermined conditions to cause said interrupter to move from one positionto the other, irrespective o! the podtion of said handle means, means,

. operable when said handle means is heldin a predetermined position, to cause said interrupter to return automatically to said rst position, following the operation of said electro-responsive means, and releasable means for holding said handle means in said predetermined position.

l2. In a .circuit interrupter, contact means movable between-two positions to open and to close the circuit, and actuating means for said contact means, said actuating means including a handle member movablek to cause said contact means to move -Irom one position to the other, means for restraining said handle in one position, and means operable upon the occurrence of predetermined conditions, when said handle is held in lone position by said restraining means, to causeysaid .contact means to move from one positiongz'fto'f-the other and to automatically return-tothe original positionupon the occurrence'of other conditions. l 18.Infa;` circuit interrupter, contact means movable'between two'positions to open and to close "the circuit, and actuating means for said contact means, saidactuating means including a liandlemember movable to cause said contact rne'ans to mov'e'irom one position to the other, witlfia.v snap action, releesable means for restrainingaid` handle in one position, and means oparable upon the occurrence oiA predetermined conditions, when said handle is held in one position by said restraining means, to cause said coner with a snap actionV and to automatically retin-n to the original position likewise with a snap action after the occurrence of other conditions.

14. In a circuit interrupter, contact means rmovable to an open-circuit and to a closed-circuit position, and actuating means for said contact means, said actuating means including means which is operable upon the occurrence of predetermined conditions to cause said contact means to move from one position with e.l snap action to the other position, to remain in said other position for a predetermined short interval of time, and to then return to said first position, likewise with a snap action, and which is operable upon the occurrence -of other predetermined conditions `to cause said contact means to move from fone position to the otherv position with a snap action, to remain in said other position for a predetermined .longer interval of time, and to then return to said ilrst position also with a snap action. v

l5.` In a circuit interrupter, contact means movable to an open-circuit and to a closed-circuit position, and actuating means for said contact means, said actuating means including a `handle means movable to cause said contact moans to move from one position to the other and spring means operatively interposed between sr-id handle means and-said contact means for causing said contact means to move with a snap 'ac-tion to each of said positions upon movement of said handle means, electroresponsiv'e means operable upon the occurrence of predetermined conditions to cause said interrupter to move from movable to an open-circuit and to a closed-cir-f cuit position, and actuating means for said contact means, said actuating means including a handle means Amovable vto cause said contact means to move from one position to the other,

electro-responsive means operable upon the occurrence of predetermined conditions to cause said interrupter to move from one position to the other, irrespective ofthe position of said handie means, means automatically operable to cause said interrupter to return to said first position,

- upon the occurrence of other predetermined conditions following the operation of said electroresponslve means, and said handle means being incapable o1' returning said contact means to said rst position after the occurrence of the first Isaid predetermined conditions until the occurrence of said other predetermined conditions.

1'1.' In a circuit interrupter, contact means movable to an open-circuit and to a closed-circuit position, and actuating means for said contact means, said actuating vmeans including a handle means 'movable to cause said contact means to move from one position to the other and spring means operatively interposed between said handle means and said contact means for causing said contact means to move with a snap action to each of said positions upon movement of said handle means, electro-responsive means operable upon the occurrence of predetermined conditions to cause said interrupter to vmove from one position to the other, irrespective of the position of said handle means,v means automatically operable to cause said interrupter to return to said rst position, upon the occurrence of other predetermined conditions, following the operation of said electro-responsive means, and said handle means being incapable ofreturning said' Contact means to said first position after the occurrence of the iirst said predetermined conditioiis` until the occurrence of said other predetermined conditions.

18. In a circuit interrupter,v contact means movable between two extreme positions to open and to close the electrical circuit through said interrupter, and actuating means for said contact means. said actuating means including an operating member, an over-center spring associated therewith, said operating member being movable to cause said over-center spring to move said contact means from one'position to the other with a' snap action, and automatic means operable upon the occurrence of predetermined conditions to cause said over-center spring to move said contact means from onev position tothe other, irrespective of the position of said operating memn 6 ber, with a snap action, and to automatically return said contact means to the original position after a time delay.

19. In a circuit interrupter, a stationary contact means, a pivotally supported switch arm for cooperating therewith to open and to close the electrical circuit through said interrupter, and actuating means for said switch arm, said actuating means including an operating handle, an over-center spring intermediate said'operating handle and said switch arm, said operating handle being movable to cause said over-center springto move said switch arm to either the open circuit or the closed circuit position with a snap' action, and autom tic means operable independover-center spring to move said switch arm from one position to the other and to automatically return said switch arm to the original position after a predetermined time delay, said automatic means including a thermally responsive bimetallic means which is movable to cause a displacement, relative to the pivot point of said switch arm, of the line of action of said over-center spring.

20. In a circuit interrupter, a stationary contact means, a pivotally supported switch arm for cooperating therewith to open and to close the electrical circuit through said interrupter, and actuating means for said switch arm, said actuating means including an operating member, an over-center spring intermediate said operating member and said switch arm, said operating member being movable to cause said over-center spring to move said switch arm to either the open circuit or the closed circuit position with a snap action, and automatic means operable upon the occurrence of predetermined conditions to cause said over-center spring to move said switch arm from the closed-circuit position to the open-circuit position with a snap action, irrespective of the position of said operating member, and'to automatically return said switch arm to the closed-circuit position following a predetermined time delay, said automatic means including a current-carrying bimetallic means which is movable to cause a displacement, relative to the pivot point of said switch arm, of the line of action of said over-center spring, and means for causing said current carrying bimetallic' means to be energized in response to the current flowing in the circuit controlled by said interrupter."

21. In a circuit interrupter, contact means` movable to an open-circuit and to a closed-circuit position, and actuating means for said contact means, said actuating means including an over-center spring, a handle means movable to .cause said over-center spring to move said contact means from either position to the other with a snap action, current-carrying bimetallic means operable upon the occurrence' of predetermined conditions to cause said over-center spring to move said contact means from the closed-circuit position to the open-circuit position, irrespective of the position of said handle means,

and means automatically operable to cause said over-center spring to return said contact means to said iirst position upon the occurrence of predetermined conditions following the operation of said electro-responsive means.

22. In a circuit interrupter, a, contact means movable to an open circuit and to a closed circuit K position, an actuating means for said contact f means including a handle, means operable in response to movement of said handle to move said contact means from one position to the other' with a snap action, electro-responsive means operable upon the occurrence of predetermined conditions to cause said conta-ct means to be moved from one position to the other, irrespective ofthe position of said handle means, and i means automatically operable to cause said contact means to .be returned to said ilrst position upon the occurrence of other predetermined conditions following the operation of said electroresponsive means.

23. In a circuit interrupter, a contact means movable to an open and to a closed circuit position, an actuating means for said contact means including a handle, means operable in response to movement of said handle to move said contact means from one position to the other with a snap action, electro-responsive means operable upon the occurrence of predetermined conditions to cause said contact means to be moved from the closed circuit position to the open circuit position with a snap action, ir` respective of the position of said handle, and means automatically operable to cause said contact means to be returned to said closed circuit position, likewise with a snap action, upon the occurrence of other predetermined conditions following the operation oi' said electro-responsive means.

24. In electrical apparatus, means movable between two extreme positions to eiIect the operation of said apparatus, and actuating means for said movable means, including a currentcarrying, thermally responsive means operable upon the occurrence of predetermined conditions to cause said movable means to move from one of said two extreme positions to the other and to automatically return to the initial position after a predetermined time delay, the current-carrying path through said thermally responsive element being so arranged that upon the occurrence of other predetermined conditions said actuating means is caused to move said movable means from one of said two extreme positions to the other and to automatically return to the initial position after a different predetermined time delay.

25. In electrical apparatus, means movable between two extreme positions to effect the operation of said apparatuaand actuating means for said movable means, including means operable upon the occurrence of predetermined conditions to move said movable means from one of said two extreme positions to the other with a snap action, to cause said movable means to remain in said other position for a predetermined short interval of time, and to then return said movable means to said rst position, likewise with a snap action, and operable upon the occurrence of other predetermined conditions to move said movable means from one position to the other with a snap action, to cause said movable means to remain in said other position for a predetermined longer interval of time, and to then return said movable means to said .rst position also with a snap action.

26. In electrical apparatus, means movable between two extreme positions to effect the operation of said apparatus, and actuating means for said movable means, including means for establishing a looped current-carrying path through said interrupter, at least a portion of said path comprising a member of thermally responsive material, which is movable from a normal inoperative position to an operative position, and means operablein response to movement of said member to said operative position to cause said movable means to be moved from one` of said two positions to the other and to be returned automatically to the initial position, said movable portion being movable to said operative position either in response to the heating effect of the current ilowing through said electroresponsive element or in response to the magneticeilectreaultingfromsaidloopedcunent carrying path.

27. In a circuit interrupter, contact means movable to an open-circuit and to a closed-circuit position, and actuating means for said contact means, said actuating means including a handle means movable to cause said contact means to move from. one position to the other, thermally responsive means heated upon the occurrence of predetermined conditions to cause said interrupter to move from one position to the other, irrespective of the position of said handle means, and said thermally responsive means being operable to cause said interrupter to return to said first position, upon cooling.

28. In a circuit interrupter, separable contacts for opening and for closing the electrical circuit through said interrupter, actuating means for said separable contacts including an operating member movable to normally cause said contacts to move either to the open or to the closed-circuit position, electro-responsive means operable upon the occurrence of predetermined conditions to cause said actuating means to move said contacts to the open circuit position, and means operable only after said contacts have been moved to the open-circuit position as a result of the actuation of said electro-responsive means, for causing said actuating means to return said interrupter automatically to the closed-circuit position.

29. In an automatically reclosing circuit breaker, contact means movable to an open and to a closed-circuit position, actuating means for said contact means including an operating member which is movable between two positions to cause said contact means to be moved to the open or to the closed-circuit position, electro-rponsive means operable upon the occurrence of predetermined conditions to cause said actuating means to move said contact means to the opencircuit position, and means for causing said actuating means to automatically reclose said contact means following each opening operation which is caused by said electro-responsive means, said means for causing automatic reclosing being inoperative when said contacts are moved to the open-circuit position by movement of said operating member.

30. In a circuit interrupter, contact means movable to an open and to a closed-circuit position, actuating means for said contact means including manually operable means for causing said contact means to be moved to the open or to the closed-circuit position, electro-responsive means operable upon the occurrence of predetermined conditions to cause said actuating means to move said contact means to the open-circuit position independently of the position of said manually operable means, and means for causing said actuating means to automatically return said contact means to the closed-circuit position following each opening operation caused by the operation of said electro-responsive means, said means for causing automatic reclosing being operable only after those opening operations which are caused by said electro-responsive means.

31. In a circuit interrupter, contact means movable to an open and to a closed-circuit position, actuating means for said contact means including an over-center spring means and an operating member, which is movable to cause said over-center spring means to move said contact means from one position to the other with automatically to the closed-circuit position upon the occurrence of a predetermined condition following each opening operation which is caused by. the operation of said electro-responsive means.

OLIVER s. JENNmGs.

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