US2435305A - Circuit breaker - Google Patents

Description

Feb. 3, 1948. G. G. GRISSINGER ETAL 2,435,305

C IRCUIT BREAKER Ifiled Oot. 18, 1941 6 Sheets-Sheet 1 WITNESSES:

Feb. 3, 1948. G. as. GRISSINGER ET AL 2,435,305

CIRCUIT BREAKER I Feb. 3, 1948. G. G. GRxsslNGER ET AL 2,435,305

CIRCUIT BREAKER Filed Ot. 18, 1941 6 Sheets-Sheet 3 r1 I i 1 Igor edi/wn er, 70m: fno/franz y and fr-ome 500e/ff).

Feb. 3, 1948.

G. G. GRISSINGER ET AL CIRCUIT 'BREAKER Filed Oei. 18, 1941 6 Sheets-Sheet 6 t @MYR/5% Patented Feb. 3, 1948 CIRCUIT BREAKER George G. Grissinger, Wilkinsburg, Turc lLindstrom,

Edgewood, and Jerome Sandin, Forest Hills, Pa., assignors to Westinghouse Electric Corporation,

East P tion of Pennsylvania ttsburgh, Pa., `a corpora- Applcation October v18, 1941, Serial No. 415,616

(Cl. 20o-109) 25 Claims.

This invention relates to circuit breakers, and more particularly to circuit breakers of the type wherein the contacts are trip free of the operating handle and are operable by the operating handle and also automatically operable in responseto abnormal circuit conditions.

Trip free circuit breakers cannot be closed or held in closed circuit position by the manual operating handle during the existence of predetermined abnormal circuit conditions, due to the rtrip free construction yof the mechanism of such breakers. Under certain conditions however it may be desired to eiect closing of Ia circuit breaker against an abnormal circuit condition, and it may be important to maintain a circuit breaker `in closed circuit position and kprevent opening thereof by any means either by predetermined abnormal circuit conditions or by severe shocks or jars which otherwise would cause opening of the breaker. l

vAn object of the invention is the provision of a trip free circuit breaker embodying an improved locking means which is settable to a locking position in which it is eiiective to prevent opening of the circuit breaker either in response to abnormal rcircuit conditions or by jars or `shocks which would otherwise cause opening yof the breaker.

Another object of the invention isthe provision of a trip free circuitbreaker embodying an improved locking device which is operable topermit vthe circuit breaker to be closed against an abnormal .circuit condition, and whichis also operable to a position in which it locks the circuit breaker closed to prevent opening thereof either'by abnormal circuit conditions or by yjars or shocks which would otherwise cause opening rof'the breaker.

"Another objectof the invention is the provision/oi a circuit breaker having a manually operable unitary means whichis operable to a locking position to simultaneously lock the trip device "against trippingvmovement and to'lock the operating handle against opening movement.

Another object of theinvention isto provide '5a circuit breaker embodying a slidable interposer "which'isv settabletoy alocking position for locking the tripjdevicewandtheoperating handle of the breaker against operation'to openthe breaker. Another object ofthe` invention is to provide '2 a circuit v:breaker withaniinterposer which is operable -to prevent opening of the breaker, the interposer being operated to locking position yby means of .an overcenter toggle to prevent accidental movement of the interposer ,to unlocking position.

Another object of the invention is the provision of a circuit breaker embodying an vimproved lockingdevice comprising a unitary locking member which isfmovable to a locking position by ya rotatable handle knob and toggle in which position the locking member is eiective to lock the trip device and Valso to 'lock the operating `handle against opening movement, the-handleknob havingzlocking means associatedtherewith to lockthe locking device in locking position.

Another object of the inventionis to rprovide a circuit breaker with asingle member which'is movable to a positionin'thepaths .ofvtravelofa trip member andthebreaker operating mechaitself, however, both as to structure and operation,`together withladditional objects and advantages thereof, will' behest understood from the .following description of Aseveral embodiments thereof when read in conjunction with the accompanying drawing in which:

Figure l is'affrontelevationalview of a threepole circuit breaker with the cover partly broken away t-o show one pole of thebreaker, the operating mechanism and the locking mechanism embodying the principles of the invention.

Fig. 2is la vertical sectional view taken substantially on line II-II of Fig. l showingtheoperatingv mechanism andthecenter pole Contact structure.

Fig. 3 is) a side elevational tion, illustrating thelocking mechanism in side view,"part1y in sec 3 elevation and showing a vertical section through the trip device of the breaker.

Fig. 4 is a fragmentary horizontal sectional view taken substantially on line IV-IV of Fig. 1 and showing the locking mechanism.

Fig. 5 is a fragmentary view in front elevation with the cover partly broken away showing a part of the operating mechanism and showing the locking mechanism in operated or locking position.

Fig. 6 is an enlarged exploded view in perspective showing the detail construction and shapes of the several parts of the locking device,

Fig. 7 is an enlarged fragmentary view in side elevation of the locking mechanism,

Fig. 8 is a detail view of the locking member shown in Fig. 4,

Fig. 9 is a front elevational View of a three-pole circuit breaker having the cover partly broken away to show the breaker structure and to show a modified form of the locking mechanism as applied to a diierent type breaker,

Fig. 10 is a fragmentary front elevational view of the modication of the locking mechanism and showing the locking mechanism in locking position,

Fig. 11 is an enlarged exploded view in perspective of the modied form of the locking mechamsm.

Fig. 12 is a vertical sectional view taken substantially on line XII- im of Fig. 9 showing the trip device and operating mechanism of the circuit breaker to which the modied form of the locking device is applied.

Fig. 13 is a fragmentary vertical sectional view through the trip device and showing the modied looking mechanism in side elevation, and

Fig. 14 is a fragmentary horizontal sectional View taken substantially on line XIV-XIV of Fig. 9, showing the modified locking mechanism.

The three-pole circuit breaker illustrated in Fig. l comprises in general, a base 1 of molded insulating material, a cover 9 of similar material secured to the base by means of bolts I I, contact actuating means indicated generally at I3 and a, trip unit indicated generally at I5. The casing formed by the base and cover is divided into three longitudinal compartments at the upper end thereof by partitions I4 formed integral with the base. Each compartment is adapted to receive a stationary Contact I6 (Fig. 2) and a cooperating movable contact I8 which with their corresponding terminals I1 collectively form the three poles of the breaker.

The partitions I4 form insulating barriers between the contact means of each pole of the breaker and align with similar partitions formed in the cover 9.

Three terminals I1, only two of which are shown, are secured in openings formed in the base at each end thereof; one terminal at each end being provided for each pole of the breaker. The respective movable contacts I8 one for each pole of the breaker, are each carried by a pivoted channel-shaped frame I9. The channel-shaped frames are rigidly fastened for movement together by means of a steel tie bar 2I which extends across all of the poles of the breaker. The tie bar is axed to the frames adjacent the pivoted ends thereof by means of iron straps 23 vwhich loop about the bar and have projecting ends extending through openings in the frames and which are clinched thereagainst. An insulating tube 25 is disposed about the tie bar 2I in order to prevent the short circuiting of the poles 4 of the breaker. The bar serves to mechanically interconnect all of the channel-shaped contact supporting frames I9 and thereby makes it possible to operate all three of the frames from a single actuating mechanism to be hereinafter described. The channel-shaped frame I9 of the center pole of the breaker is pivotally supported on a pin 21 carried by a U-shaped main frame 29 of the common actuating mechanism. The other channel-shaped frames may be pivotally supported on other pins, not shown, which are mounted on supports extending from the base.

The movable contacts I8 are each carried by an arm 20 pivoted to its corresponding channelshaped frame I9 by means of a pin connection 3i. The particular contact means do not form an important part of my invention and hence, will not be described or shown in detail. Suitable arc extinguishing means 33 of the spaced plate type may be provided for the contact means of each pole of the breaker.

The single actuating means I3 comprises in Ygeneral the U-shaped main frame 29, a carrier or support member 35 pivoted to said frame, a pair of toggle links 31 and 39 interconnecting the carrier member and the channel-shaped contact supporting frame I9 of the center pole of the breaker, a U-shaped operating lever 4I, overcenter springs 43 for connecting the operating lever to the knee pivot pin 45 of the toggle links, and an operating handle 41 for the lever.

The U-shaped main frame 29 is secured to the base 1 by means of bolts 49 which extend through the frame and base and engage inserts disposed in recesses in the base. The lower toggle links are pivoted to the channel-shaped frame I9 of the center pole by means of a pin 5I, while the upper toggle links are pivotally connected to the carrier by means of a pin 53. The legs of the operating lever are pivotally supported on members 55 projecting from the sides of the main frame 29. The operating handle projects through a slot 51 provided in the cover 9 and has a curved protective portion 59 for closing the slot. The operating lever is provided with a hook EI for engaging and moving the carrier member 35 to reset the member 35 when the operating handle is moved to its open position after a tripping operation. The carrier member is pivoted to the main frame by a pin 63 and is adapted to be moved by the hook 6I to its latched position, in which its nose or latch engaging portion 59 is releasably held by a latch of the trip unit to be hereinafter described. Movement of the operating lever is limited by stop lugs struck in from the main frame and by a transverse portion 51 of said frame.

The operation of the circuit breaker actuating means is as follows. With the parts in the position shown in Fig. 2, in which all of the contact means are closed and in which the carrier member is held in the latched position; if the operating handle 41 is moved from the position shown to the opposite end of the slot 51 to rotate the lever 4I in a clockwise direction, the overcenter springs 43 will snap over and cause the toggle links 31-39 to collapse. The collapse of the toggle links causes a simultaneous movement of all of the channel-shaped frames I9 and movable contacts I8 to the open circuit position with a. snap action. To close the breaker the operating handle is moved in the opposite direction back to the position shown in Fig. 2. This movement of the handle will cause the overcenter springs to snap over` in the opposite direction and move the toggle links to their operative position to vaway from the pole faces.

gra-tisse simultaneously close au of the-contact-'meanswith a snap action.` n l m The mechanism f the current'responsive trip unit is mounted in a compartment 1i inthe-eas-` lng andis supported bya panel y'I3 wnich'e'xtends across all the poles/of the'br'eaker; The panelisy removably mounted inthe compartment 1| by means of 'bolts 15 (Figfmi which paslsfthroiigh' member is biased in a counterclockwisedirection by means of a springf89 (Fig.n5) coiled' about the pinv 85 and which engages under the latch'meme ber at one end thereofanjd which has its other end secured against the face ofthe panel1'3. The latch 'member has a hook shapede'xtension 9| which is provided at its outer edge with a lde tent "93 adapted to be engagedy by a roller y"95 which is carried by a trip bar 91. Thetrip bar is pivotally mountedby means of brackets (not shown) extending downwardly fromthe-panel 13, and the bar extends across all 'of the poles ofthe breaker. The trip bar is biased in a counterclockwise direction, asviewedin Fig.`2, by means of a coiled spring |'0| (Fig. 2) which has one end engaged in a socket provided in the panel 13 and the other end engaging'a similar socket provided in the trip bar 91. An opening |U3-is formed in the panel to accommodate the end of the hook shaped portion 9| of thelat'ch member 83, and a bracket |05 is secured tothe trip bar to support the 'roller 95. V'Ihevtrip bar is biased yby the spring IUI to engagethe'roller 95m Y the detent 93 inthe end of the latch member. The trip bar thus holdsthe llatch member in latching position by the means described above. l

A plurality of electromagnetic tripv means |01 (Fig. A2) are provided, one Vfor each pole of the breaker. Each trip means '|01' consists of a U- shaped core ||l9ofv magnetic material secured to the panel 13 by means of bolts III. The endso'f the legs? of the U-shaped cores |09 form pole faces. Each pole face has'fa'bolt I I3 extending, therefrom for supporting-an armature H5. The 'armature consists of a nat plate ofniagne'tic ma# terial having two openings provided therein "for receiving the bolts II 3. A coiled spring I"I1l surrounds each `bolt 'and 'engages the pole 'face at one end thereof, and the armature at its other end. fThe'se springs *serve to bia's the 'armature Lock nuts II`9 are threaded on the Loute'rend of the bolts in order to adjustably position the arma-ture andto vlimit movement of the 'same awayffrein the pole faces. The trip bar -91 carries fa plurality vo'f"si;'rips |2I, one for veach pole of the breaker. The strips |2| extend at rig-ht angles to the trip bar andare adapted to be engagedby-an adjustable projectev iedby each ofthe aring bolt (not shown) cair n l matures of the trip means 'whereby-the tripjbar is adapted to be `moved to tripping position 'when' any onek of the armatures isoperated.

-The electrical connections fr yeach lpole *of the breaker are the same and are as follows:

one terminal l1. .of each 'pole vfof the breaker isy connected to the stationaryff'contact I5 by a con"e dritter |25. frhe other Y is connected, by aconductor-bar |21, which has'a looped portionl` |29 lextending around the bight ofthe U-'shaped core |09 of its trip element, to a fiexible'conductor |`3| which is connected, in turn, 'to the movable contact I8'. The looped shapedportion |29 of the conductor |21 fornisnI coil for the core of thetrip means. C urrent passes from one terminal vI1of the breaker through the conductor member |21, around .the loop i29'to the exible conductor |3I, thence to the movable contact I8, the stationary contact Island the conductor |25 to the other terminal I1. 'I'he connections for each pole of the breaker are the same, hence each trip means is responsive to the current ilowingthrough its corresponding pole and is operative when an overload of predetermined magnitude occurs therethrough to move the trip bai-'91 to its tripped position.

The operation of the trip unit is as follows: With the parts of the circuit breaker in the position shown in Fig. 2, i. e., with the contact means in the closed circuit position and the carrier mern ber in its latched position; if an overload occurs in any ofthe circuits extending through the poles of the breaker, 'the 'corresponding electromagnet formed by the U-'shaped core |09 and looped conductor |29 is energized, its armature ||5 is attracted and engages the strip I2I rotating the trip `bar 91 in a clockwise direction as viewed in Fig. 2. Rotation of the trip bar 91 in the clockwise direction moves the roller 95 out of engagement with the detent 93 inf'the latch member 83, thus releasing the same. The carrier member 35 being biased in a counterclockwise direction by the overcenter springs 43 partially rotates the latch member in a clockwise direction, thus freeing its latch engaging portion 81 from engagement with the latch portion69 ofthe carrier member. When the carrier member is thus released, the toggle links 3-1-39are'col1ap`sed by means' of the overce'nter springs '43 and cause the channel shaped frames I9 to move the movable contacts I8 to an open 'circuit position. The breaker cannot be reclos'ed until the operating handle has been moved to full open position in order to reset and latch the carrier "meinben After the carrier member has been reset, the operating handle may then be moved to its closed circuit position to effect closing o'f the contact means.

The locking device I2 appears in the drawings in Figs. 1 to '8, inclusive. Referring to Figs. 1 and 6, the locking device is supported on a mounting bracket |33 having a horizontally extending portion` |35 s'ecredv by screws |31 to the panel 13 which Vsi1i'naci1"ts the trip device I5. The main body |39 ofthe bracket |33 extends vertically and has secured thereto, by means of a screw I 4|, a member |43 of molded insulating material. As an additional support for the locking device, a portion |545 of the member |43 extends to the left (Figs. 1 and 5) toward the rear of the breaker (Fig. 4). Aslot |41 (Fig. 4) in the portion |45 nts snugly over the right-hand one of the partitions I4 (Fig. 1). The cooperation of the portion I 45 andthe partition I4 can best be seen in Figs. 4, 5 and 7.

In order to lock vthe breaker in a manner to render the V`trip device I5 ineffective to trip the operating mechanism and to lock the operating mechanism against circuit opening operation, there is provided a'locking member |49. This member is of irregular shape (Figs. 6 and 8) and isrslidablyV mounted' on a cylindrical projection f Ii5| extending'to'ward the center pole ofthe breakterminal I1 of each pole er from the mounting bracket |33. The end of the cylindrical member |5| is provided with an opening |52 (Fig. 6) into which projects one end of the pin 85 upon which the latch member 83 is mounted as best seen in Figs. 1 and 5.- The locking member |49 is disposed vertically in the breaker (Fig. l) and is provided with a locking projection |53 at its upper end and a locking projection |55 at its lower end.

The locking member |49 is adapted to be moved to locking position (Fig. 5) and to unlocking position (Fig. 1) by rotation of an operating device |51, the details of construction of which may best be seen in Figs. 4 and 6. The operating device |51 is rotatably mounted in a cylindrical portion |59 of the molded member |43 which projects horizontally through an opening in the cover 9 (Figs. 2 and 3). The operating device |51 comprises an operating knob |6| of insulating material, a crank disc |53 (Fig. 4) and a connecting shaft |65 of molded insulating material. The knob |6| is rigidly secured to the shaft |65 by means of a screw |61 which extends axially through the knob and is secured in a metal insert |69 molded into the outer end of the shaft |65. 25

An insert |i| integral with the crank disc |63 is molded into the inner end f the shaft |65 and thereby rigidly secures the crank disc to the shaft.

The crank disc |63 is connected to the locking member |49 by means of a link |13 which is pivotally connected to a pin |15 on the crank disc and to a pin |11 on the locking member. Cotter pins |19 or other suitable retaining means may be used to retain the link |13 in cooperative relation with the pins |15 and |11. The link |13 passes through an opening |8| in the member |43 (Fig. 6) provided therefor.

Referring now to Fig. 1, rotation of the knob |6| of the operating device |51 through an angle of approximately 90 in a clockwise direction thrusts the link |13 and the locking member |49 toward the left to the locking position in which it appears in Fig. 5. In the locking position of the member |49 the locking projection |55 occupies a position in the path of travel in unlatching direction of the yoke 66 of the latch member 83 (Figs. 2, 3, and '7). A positive lock is formed by the projection |55 which prevents movement of the latch member 83 to free the' carrier 35. Thus, with the locking member |49 in locking position, the trip device l5 is rendered ineiective to trip the breaker.

The movement of the locking member |49 in locking direction also interposes the projection |53 in the path of travel of the operating lever 4|, thereby preventing movement of the operating mechanism in contact opening direction. Rotation of the knob |6| from the locking position (Fig. 5) in a counterclockwise direction to the unlocking position (Fig. 1) moves the locking member |49 toward the right withdrawing the projection |55 and |53, respectively, from the paths of the trip member 83 and the operating lever 4|, as shown in Fig. 1.

Before the knob |6| can be rotated in either direction, it is necessary to pull it outwardly toward the front of the breaker (Fig. 1) which is toward the right (Figs. 2 and 3). Referring to Fig. 6, the outer end of the cylindrical portion |50 of the member |43 is provided with two pairs of projections E63 and |85. The inner end of the knob |6| is provided with a pair of diametrically opposed projections |81 adapted `to nt in the spaced recesses between the projections |83 and |85 and the portions |59.n The projections |65 are shorter than the projections |63 which serve as limit stops to limit the rotation of the knob |6| in either direction. The radially inner ends 5 of projections |81 on .the knob |6| extend into notches |89 in the shaft |65 in order to communicate the rotary movement of the knob |6| to the shaft |65 and to the crank disc |63. Since the knob |6| is rigidly secured to the shaft |65 by means of the screw |61, and since the inner ends of the projections |81 are permanently engaged with the notches |89 in the shaft |65, the knob |6|, shaftl65 and crank disc |63 move as a unit both axially and rotatively. It will be noted that the crank disc |63 (Fig. 4) fits within an opening in the inner end of the molded member |43 which is provided with a shoulder |9| (Fig. 4). When the knob |6|, shaft |65 and crank disc |63 are drawn outwardly in order that the o projections |61 may clear the projections |65,

the crank disc |63 strikes the shoulder |9| limiting the outward movement of the knob beyond that necessary for the projections |81 to clear the projections |85. The member |43 is provided with a shoulder |93 (Fig. 4), and a coil spring |95 compressed between this shoulder and the crank disc |63 biases the knob assembly |51 comprising the crank disc |63, the shaft |65 and the knob |6| inwardly to engage the projections |81 with the selected recesses formed by the pro- .jections |83 and |85.

It can be seen, therefore, that in order to move the locking member |49 from the unlocked to the locked position, or vice versa, the knob |6| is rst drawn outwardly, then rotated approximately 90 to the selected position, or until the projections |81v strikeY the projections |83 and then released. The knob lock prevents any jarring force from causing undesired rotation of the knob and crank disc |63.

Referring to Fig. 5, when the knob |6| is rotated to move the member |49 to the locking position, the vpin |19 is moved over center above a line drawn through the center of the pin |11 and the center oi the knob assembly. The toggle thus formed acts as an additional means for preventing accidental movement of the locking member |49 to unlocking position.

The side of the projection |55 which engages the latch member 83 is slightly tapered so that as the member |49 is moved to locking position and the projection engages the latch 83, the latch is rocked slightlyA counterclockwise (Figs. 2 and 3) to removethe load from the latch 55 roller 95. y

Adjusting screws |91 and |99 (Fig. '1) are provided whereby the position of the projection |55 may be adjusted. relatively to the latch member 83. This adjustment is effected by slightly rotating the locking member |49 in either direction about the projection |5| on which the member |49 slides. The screws |91 and |99, respectively, are provided with lock nuts 20| and 203. The adjusting screw |91 is mounted in a threaded 65, opening 205 in a, formed projection 201 integral with the mounting` bracket |33 (see also Fig. 6). The lower end of the screw |91 is rounded and bears against a projection 209 forme-d integral with the locking member |49 (Figs. 7 and 8).

The adjusting screw |99 is mounted in a threaded opening 2|| (Fig. 8) in a portion 2|3 of the member |49 and bears against the upper face of the projection 201.

Obviously, 4rotation of the screw |91 in a. direction to move itfartherr into'the opening 205 and i at the same time `backingthe screw |99out will result in rotating the member |49 in a counter'- clockwise direction (Fig. '1) which will move the projection |55 toward the left as viewed in Fig. 7 or closer to the yoke 86. of the latch member 83 (see also Figs. 2 and 3). Reversal of the rotation of the member |49 is obtained by moving the screws |91 and |99 in the opposite directions.

If the breaker is .standingV in the open position withthe operating handle 41 in the opposite end of the slot 51 from which it appears in Fig. 2, the operating lever 4| will occupy a position in the path of travel of the projection |53. Inspection of Fig. 1, however, discloses that the locking member |49 may move toward the left a suiiicient distance to engage the projection |55 with the latch member 83 before the projectionfl 53 strikes the lever 4|. This permits locking the trip member against tripping if an overload circuit condition is present when it is desired to close the.

circuit. After moving the locking member |49 until the projection |53 strikes the lever 4|, the operating handle .41 is moved to the closed position (Fig. 2) closing the conta-cts. The handle 41 is held in the closed position while knob |6| isy rotated the remainder of the distance to locking position which moves the .projection '|53 under the lever 4|, i. e., into the path of opening movement of the lever 4| and thus locks the breaker closed even though an overload condition which would normally trip the breaker open exists in the circuit controlled by the breaker and against shock which would tend to cause the handle to moveto open position.

Figs. 9 to 14, inclusive, illustratel a modied form of the inventionv applied toa circuit breaker of the same general type as thatpreviously described but having a somewhat different form of operating mechanism. Referring to` Figs. 9 and 12 of the drawings, the breaker shown therein -is also of the three-pole type andis of 'the same general construction as the circuit breaker fully described in U. S. Patent No. 2,083,304, issued June 8, 1937, to 'I'ure Lindstrom and assigned to the assignee of the present invention. For a more detailed description of the main breaker construction and jits operation, reference may be had to the abovementioned patent.

The circuit breaker comprises, in general, a

. .casing 2|5r of molded insulating material having a removable cover 211 secured thereon, stationary contact means 2 I9, cooperating movable contact means 22|, an operating mechanism 223 and l a unitary trip device 221.

Three sets of stationary and movable contactV means 219 and 22| are provided forming the three poles of the breaker. The movable contact members 225 of the movable contact means 22| for rthe 4center pole are pivotally mounted at 229 on a lmovable switch member 23|, and are biased toward the stationary .contact means 2|9 relative to the switch member 23| by means of springs 233 carried by the switch member. Suitable stops are provided on the switch'member for limiting the counterclockwi-se movement of the contacts 225 relative to the switch member when the contacts are separated.

The switch member 23| is pivotally mounted by means of a pivot pin -235 on a U-shaped main frame 231 which alsosupportsthe circuit breaker operating mechanism 223, The movable contact members for the two outer poles (only the left-:hand one being shown in Fig, 9) are also carried by switch members which are mechanically connected .for simultaneous movement with the center pole switch member. 23| by means of a rigid tie bar 239 which extends transversely across the three poles of the breaker. Each switch member is clamped to the tie bar 239 by a clamp 24|, and the switch members are insulated from each other by means of insulating sleeves 243 surrounding the tie bar 239.

The several poles of the breaker are insulated from each other by means of insulating barriers 245 molded in the casing 2 I5, which are in alignment with similar barriers 241 molded in the cover 2|1. Each pole of the circuit breaker is provided with an arc extinguisher 249 for extinguishing arcs drawn between the arcing contacts during rupture of the circuit. The arc extinguishers 249 may be of any suitable type but are preferably of the type fully disclosed in U. S.vr

Paten-t No. 1, 896,764, issued February '1, 1933, to M, W, Brainard, and assigned to the assignee of the present invention.

The electrical circuit for each of the poles of the breaker is the same, the circuit extending' ing a pair of toggle links 251 and 259 having one end pivotally connected to the center pole switch member 23|, a `carrier lever 26| for releasably restraining the other end of the toggle 251- 259 in operative position, a channel-shaped cperating member 263, an overcenter spring unit 265 for connecting the operating member 263 to the knee 211 of the toggle, and an operating handle 261.

The U-shaped frame 231 is positioned below the contact means of the center pole and is rigidly secured to the base by means of screws 269 and 21|. The screw 21| extends through the conductor bar 253, hencey the entire operating mechanism 223 and the frame 231 are at the same electrical potential as that of the center pole.

The toggle link 251 comprises a pair of parallel links which are rigidly joined by a yoke 21,3. One end of the toggle link 251 is pivotally connected to the center pole switch member 23| by a pivot pin 215 and the other end of said toggle link is pivotally connected to one end of the toggle link 259 by the knee pin 211.

The toggle link 259 also comprises a pair of parallel links which are rigidly joined at their upper ends by a yoke 219 which is adapted to engage the yoke 21.3 of the toggle link 251 when the breaker is in fully closed position (Fig. l2) to provide a Stop for limiting the outward motion of the knee of the. toggle.

The overcenter spring unit 265 operatively conpivotally connected to the frame 231 by `means of a pivot pin 289.

The carrier lever 26| comprises parallel bell crank levers which are joined by a yoke 281 extending parallel to the base of the casing. The carrier 26| is pivoted to the frame at the apex of the bell crank levers by means of a pivot pin 29|, The overcenter spring unit 265 at all times exerts a force on the carrier 26| transmitted through the toggle link 259, biasing the carrier lever in a clockwise direction, A latching lever 295 is provided for restraining the carrier lever 26| in operative position. The latching lever 295 also comprises a pair of parallel members which are joined by yokes 291 and 299. One end of the latching lever 295 is pivoted to the frame 231 by a pivot pin 298. The yoke 291 (Fig. 13) of the latching lever 295 normally rests in the path of the yoke 281 of the carrier lever 26| and thus holds the carrier lever in an operative position by preventing it from moving in a clockwise direction under the biasing influence of the overcenter spring 265. The free lower end oi the latching lever 295 carries a pivoted latch engaging pawl 30| supported 0n the yoke 299 of the latching lever 295, the pawl 30| and the latch lever 295 being normally restrained by the trip device 221.

The trip device 221 is preferably of the type fully disclosed in U. S. Patent No. 2,178,083, issued October 3l, 1939, to Jerome Sandin, and assigned to the assignee of the present invention.

The trip device includes an electro-magnetically responsive element for each of the poles of the breaker. Each of these elements includes a metallic yoke 303 of non-magnetic material suitably mounted by a panel 305 of insulating material. The panel 305 extends across all of the poles of the breaker and is suitably secured to the base thereof by means of a bracket 30E. The yoke 303 is U-shaped and the legs thereof support a stationary core member 301 which is suitably secured thereto by means of screws. A pair of ears 309 on the yoke 303 pivotally support a U-shaped armature 3H. Each of the armatures 3| is biased away from its stationary core member 301 by a pair of springs 3|3 surrounding studs 3 I5 which are secured to the panel 305. The springs 3| 3 are compressed between the armature 3| and washers 3 I1 which may be held in place on the ends of the studs 3|5 by any suitable means, for instance, cotter pins.

An energizing conductor 3|9 having one end electrically connected to the conductor bar 253 and the other end connected to the lower terminal 255 passages between the legs of the yoke 303 and the legs of the armature 3|| and over the stationary core 301. Current flowing through the conductor 3|9 energizes magnetic circuit including the core member 301 and causes it to attract the armature 3| Under normal current conditions, however, the springs 3|3 prevent movement of the armature. Upon the occurrence of an overload current or a short circuit, the attracting force is suiicient to overcome the biasing influence of the springs 3|3 and move the armature 3|| to its attracted position.

Operation of the armature 3|| is adapted to actuate a trip bar 32| to cause tripping of the breaker. The trip bar 32| is of molded insulating material and extends across all of the poles of the breaker. It is pivotally supported by means of a pair of lugs 323 (only one being shown) projecting downwardly from the bracket 306.

A compression spring 325 bia-ses the trip bar in a clockwise direction and maintains the latch end of an angular bracket 321 secured thereto, in engagement with a trip lever or main latch 329 pivotally supported in the bracket 306. The latch 329 engages the trip pawl 30| to normally restrain the latch lever 295 in latching position. Spaced plates 33|, one for each pole of the breaker, are secured to the trip bar 32| by means of rivets. Each of the plates 33| extends downwardly and is adapted to be engaged by the corresponding armature 3I| when the armature is operated as previously described in response to an overload current.

When any armature 3|| is operated in response to abnormal circuit conditions, the trip bar 32| is rocked counterclockwise causing the angular bracket 321 to release the main latch 329 which in turn releases the latching lever 295 thereby permitting counterclockwise movement of the latching lever 295 under the biasing influence of the operating spring unit 265. The counterclockwise movement of the latching lever 295 causes its yoke 291 to release the carrier lever 25| which is thus moved clockwise about its pivot 29| under the biasing influence of the overcenter spring unit 265 and the force exerted by the contact springs 233. This causes collapse of the toggle 251-259 toward the base and simultaneously opening of all of the contacts of the breaker.

To reset the breaker following an automatic tripping operation, the operating handle 261 is moved in a clockwise direction to the "oflm position. This operation of the handle causes a pair of rollers 333 on the operating member 263 to engage and reset the carrier lever 26| and the latching lever 295 to their latched positions. The breaker may then be reclosed by moving the operating handle 261 in a counterclockwise direction to the on position.

In order to open the circuit breaker manually, the operating handle 261 is moved in a clockwise direction from the position in which it appears in Fig. 12 to the opposite end of the slot 293. When the handle has been moved a short distance, a projection 335 on the operating member 263 engages the yoke 213 of the toggle link 251 and positively starts the knee 211 of the toggle 251-259 toward the base of the breaker. At the same time, the operating spring unit 265 has been moved across the center line of the toggle link 259 and now exerts a force in a direction to move the knee of the toggle toward the base. The movement of the several parts of the operating mechanism is now automatic and all of the contacts are opened simultaneously with a snap action.

To close the contacts after they have been opened manually the operating handle 261 is moved in a counter-clockwise direction carrying the line of action of the operating spring unit 205 over the center line of the toggle link 259. The operating spring unit then exerts a force biasing the knee of the toggle 251-259 outwardly from the base, causing straightening of the toggle and closing the contacts for all of the poles with a snap action.

It can be seen that operating member 4I and the latch member 83 of the circuit breaker shown in Fig. 3 move in the same direction to eiect opening of the breaker. It can also be seen that the operating member 263 and the latching lever 295 (Fig. 12) of the breaker described in connection with the modified form of the locking mech- '13 anism move` in opposite directions. This fact andfthe' shapes of the movingvk parts imposes a diierent problem in effecting the positive locking of the breaker in the closed contactposition.

In order to effect locking of the operating mem ber 263 and the latch lever 295 against movement to cause opening of the contacts a pivoted lock member 331 (Figs.` l2 to 14, inclusive) is provided. The locking member 331 is provided with a hub 338 (Fig. 11) and is pivotally mounted on a horizontally disposed stud 339 molded into and projecting from a portion 340 of a member 34| of molded insulating material. The member 34| is secured to a metal bracket 343 by means of screws 345 with an angular plate 341 of insulating material therebetween. The bracket 343 is bent inwardly toward the baseof the breaker and has a mounting foot formed on the inner end which is secured to the conductor 3|9 for therighthand pole (Fig. 9) by means of screws 349 with which the conductor 3 |9 is secured to the bar 253 for that pole and to the base 2 I 5.

Av retaining collar 35| (Fig. 14)` secured to the end of the stud 339 bears against the barrier 245, and a` member 353 (Fig. 14) secured to the bracket 343 by the screw 345 is provided with an enlarged portion355 which bears against the side of the casing 2|5 to provide a snug ilt for the locking device between the right-hand barrier 245 (Fig. 9) and the wall of the casing 2|5 (Fig. 14).

The locking member 331 is operatively connected to a crank disc 351 (Fig. 14) by means of a link 359, one end of which cooperates with a pin 36| projecting from an ear 363 on the locking member 331 (Fig. 11) and the other end of which link cooperates withA a pin 365 (Figs.v 9 and 10) on the crank disc 351. I'he crank disc is secured to the inner end of a shaft 358 of insulating material having a knob 361 secured to its outer end. The construction of the knob `361 and its associated parts for operating thelocking member 331 is identical with that described previously and illustrated in Fig. 4 lof the drawings forwhich reason it is not believed necessary to repeat the description herel When the knob 361 is drawn outwardly and rotated in a clockwisedirection from the position in Fig. 9 to its, Fig. 10 position, the crank disc 351 is rotated therewith and thrusts the link 359 toward the center pole of the breaker rotating the locking member 331 to the locking position in which it appears in Fig. 10. Referring to Fig. 14, as the locking member 331 is moved toward lockingy position, the edge 369 thereof engagesY the rounded corner 31| of the yoke 299 of thelatching member295 and rocks this member slightly in a clockwise directionv (Fig. 13) to move the latch pawl 30| slightly away from the trip lever 329.4 The engagement of the member 33 1 with the latching member 295 prevents unlatching of the carrier lever 26|, thus rendering the trip device 221 ineiective to trip the breaker inv response to overload conditions, and also preventsk shocks or jars from tripping the breaker,

Movement of the locking member 331 to locking position also positionsV the iiattened apexof projection 313 thereon into the patch of travel of a portion 315 (Figs. k1() and 13) of the operatingf member 263.V Should the operating member 2 63 be moved clockwise toward opening position, the portion 315 thereof will strike the projection 313 of the locking member which arrests the opening movement of the operating member before the projection 335 thereon strikes the 'yoke'V 213 :offthetoggle link 251 (Fig. 12) and before the operating-V member has travelledV a sufficient distance to move the yoperating spring unit 265 over the centerline of the toggle link 259. Thus the tension of the powerful spring unit 265 is maintained in a position to hold the toggle 251- 259 vin straightened condition which holds the contactsclosed `regardless of the condition of the circuit, and also against any shock or jarring force.y

It was statedpreviously that the entire operating mechanism 223 including the operating member 263 and the latching lever 295 are at the same electrical potential as that of the center pole of Y the breaker. Since the metal support bracket 343 for the locking device is secured to the con,- ductor 3|9,A the bracket will have the electrical potential yof the right-hand pole (Fig. 9). In order to more completely insulate the two poles concerned, there is provided an angular insulating member 311 secured to the panel 305 by means of screws 319. The insulating member 311 -isy disposed between the bracket 343 and the adjacent Acenter pole parts and the endv of the ylocking member 331. When the locking member 331 is. in locking position and, therefore, in contact withthe latching member 295, the mem ber 331` is` also at center pole potential. The member 34| Awhich is of insulating material, and the angular insulating plate 341 effectively insulate the locking member 331 and the metal parts connected thereto from the bracket 343 and hence from the right hand pole (Fig. 9)

It may be desirable to close the breaker and lock'it in closed position against an overload circuit condition.. In this case the knob 361 is drawn outwardly and rotated in a clockwise direction toward locking position. During this movement of the knob, the locking member 331 will be moved 'to a position in the path. of unlatching movement of the latching lever 295 thus preventing tripping of the breaker. However, the movement of 331 will be arrested before full locking position is reached by striking the operating member 263, which at this time is in the off .position in which it is in the-path of the locking member. While holding the knob 331 in its partially rotated position, the operating handle 261 is moved in a counterclockwise direction (Fig. 12) to its on position which closes the breaker as previously described. The locking knob 361 may now be rotated the remainder of the distance to locking position.

Referring to Fig. 10, it will be observed that with the knob 361 in the locking position the toggle comprising the link 359 and the crank disc 351 is over center above a line drawn through the center of the pin 36| and the center of the crank disc which `is in axial alignment with the knob 361. rThis overcenter condition assists in maintaining the locking-member 331 in locking position against the -eiiects of shocks or jars;

It is vobvious that rotation of the knob 351 to its unlocking position withdraws the locking member 331 from its locking position (Fig. 10) to its unlocking position (Fig. 9).

The invention provides an improved locking mechanism'lfor locking the circuit breaker in closed position and for preventing ktripping of thebreaker in response to overload conditions in the circuit controlled by the breaker. The locking devices described in the foregoing specication are of simple construction, inexpensive to manufacture and are adapted to be readily installed in circuitbreakers of the type disclosed which are already in use. The operation of the locking device is simple and positive, the locking of both the operating mechanism and the trip member being effected in both forms of the invention by a single locking member. The manuallr,1 operable locking knob is arranged to be locked in both its locking and unlocking position. This, together With the toggle connection between the locking knob and the locking member insures that the mechanism will not be displaced from its adjusted position as a result of shock or jar.

Having described several embodiments of the invention in accordance with the patent statutes,y

it is to be understood that various changes and modifications may be made in the structural details disclosed without departing from some of the essential features of the invention. It is, therefore, desired that the language of the appended claims be given as reasonably broad interpretation as the prior art permits.

We claim as our invention:

l. In a circuit breaker, a base, relatively movable contacts, an operating member movable to an Open and t-o a closed position for opening and closing said contacts, a member releasable to cause opening of said contacts irrespective of the position of the operating member, said elements being mounted on said base, and a locking element mounted on said base and movable transversely of the direction of movement of the operating member and the releasable member and into the path of opening movement of said operating member and said releasable member to prevent opening movement of said operating member and to prevent release of the releasable member.

2. In a circuit breaker, a base, relatively movable contacts, operating mechanism including an operating member movable to an open position and to a closed position for opening and closing said contacts, releasable means operable in response to predetermined conditions in the circuit controlled by the breaker for causing opening of said contacts irrespective of the position of said operating member, said operating mechanism and said releasable means being mounted on said base, a locking member mounted on said base to one side of said operating mechanism for movement transversely of the direction of movement of the operating member, said locking member being movable from a non-locking position to a locking position in which portions thereof are interposed in the path of opening movement of said operating member and said releasable means to prevent opening movement of said operating member and to prevent operation of the releasable means in response to shocks or jars.

3. In a circuit breaker including a supporting base, relatively movable contacts, operating means therefor including an operating member movable to open and to close said contacts, a member releasable to cause opening of said con- 'tacts irrespective of the position of said operating member, a latch member operable to release said releasable member, a slidable locking member mounted on said base and movable from one position to a second position to prevent movement of the operating member to open position and to prevent release of the releasable member, and means to lock said slidable member in either of its positions.

4. A circuit breaker comprising a base, a removable cover, relatively movable contacts, an

voperating member movable to an open position and to a closed position to open and close the contacts, releasable means operable to cause opening of the contacts irrespective of the position of the operating member, a locking member mounted for movement in a path perpendicular to the path of movement of the operating member, a member mounted on said base for supporting said locking member independently of said cover, said locking member being movabie from a non-locking position to a locking position in which portions thereof are interposed in the path of opening movement of said operating member and said releasable means to prevent opening movement of the operating member and to prevent release of the releasable means, and means operatively connected to said locking member and operable upon movement of said locking member to locking position for locking said movable locking member in locking position.

5. In a circuit breaker, relatively movable contacts, an operating member having a closed position and movable to an open position to cause opening of said contacts, releasable means operable to cause opening of the contacts regardless of the position of the operating member, a member slidable transversely of the operating member and operable from one position to a second position to prevent movement of said operating member to open position and to prevent operation of the releasable' means, a plurality of bearings for slidably supporting said slidable member, and means to lock said slidable member in either of its positions.Y

6. In a circuit breaker, a base, a cover removably mounted thereon, relatively movable contacts and operating mechanism therefor mounted on said base, said operating mechanism including an operating member movable to an open position and to a closed position for opening and closing said contacts, means releasable to cause opening of the contacts irrespective of the position of said operating member, a locking member mounted on said base and movable from one position to second position to prevent movement of the operating member to open position and to prevent operation of the releasable means, manually operable means mounted on said base for positively actuating said locking member to both positions, and al toggle operatively connecting said manual means to the locking member, said toggle and said manual means cooperating to lock said locking member in either of its positions.

7. In a circuit breaker, relatively movable contacts, operating mechanism for said contacts including an operating member movable to open and to close said contacts, a releasable means operable to cause opening of the contacts, irrespective of the position of said operating member, a pivoted locking member movable from one position to one side of the operating member and said releasable means to a position between said 4operating member and said releasable means to 4prevent operation of said releasable means and also to prevent opening of said contacts, manually rotatable means for positively moving said vlocking member to both positions, and means comprising at least one projection movable with said rotatable means and engageable with a support member provided with a plurality of locking recesses to retain said rotatable means and said locking member in locking position against the eiects of shock or jar.

8. In a circuit breaker, relatively movable contacts, an operating member operable to cause kopening of the contacts, a locking opening and closing of'said contacts, a means releasable to cause opening of the contacts, a slidable member, movable transversely into the paths of movement of the operating member and the releasable means to render said operating member and'said releasable means ineffective-to 'cause opening of the contacts, manual operating means for positively moving said slidable member, and restraining means for preventing accidental movement of said manual operating means in response to shocks or jars.

9. In a circuit breaker, relatively movable contacts, an operating member operable to` cause opening and closing of said contacts, a releasable latch member movable to cause openingV of the contacts, a slidable member having a projection movable from one position to a position in the path of travel of the operating member and having a second projection engageable with the latch member to prevent opening movement of said operating member and said latch! member, manual means operatively connected to theslidable member for positively operating said slidable member to both positions, and locking means for said manual means. 1

10. In a circuit breaker, relatively movable contacts, an operating member movable to open and close said contacts,'means releasable to cause member" movable transversely of the movement of the operating member to a locking position'in which it blocks movement of said operating member to open position and prevents release of the releasable means, rotatable operating means for said locking member including a knob which is rotatable lto operate said locking member and which is also movable in the direction of its aXis of rotation independently ofsaid locking member, support means for said knob, retaining means for said operating means comprising at least one projection on said knob engageable with locking recesses on said support means to positively retain said operating means in operative position, and means elTective upon movement of said rotatable operating means to locking position 'to lock the locking member in locking position.

11. In a circuit breaker, relatively movable contacts, an operating member movable to an open and toV a closed. position for opening and closing said contacts, a pivoted latch member operable to cause opening of said contacts, a locking member slidable transversely of the movement of the operating member from one position to a second position, said locking member having a projection thereon for preventing movement of the operating member and a second projection for preventing movement of the latch member, rotatable operating means for said locking member including a rotatable pullout knob, a support member for said rotatable means, and retaining means for positively retaining the rotatable means in either position, said retaining means comprising at leasty one projection on said knob selectively engageable with a plurality of recesses in the support member.

12. In a circuit breaker, relatively movable contacts, an operating member movable to an open position and to a closed position for opening and closing said contacts, a releasable member loperable to causeopening of the contacts irrespective of the position of the operating member, a locking member movable from one position vto a second position between said operating member and said releasable member to ,prevent movevment of the operating member and of the release positions.

18 able member, operating means for positively moving said locking member to both positions including a rotatable knob which is also movable in the direction of its axis of rotation, a support for said operating means, and means comprising a part movablewith said knob and engageable with recesses in the support for positively retaining the movable locking member in either one of its 13. In a circuit breaker, relatively movable contacts,r 'an operating member for opening and closing said contacts, a releasable latch for causing opening of the contacts, a slidable member for cooperating with the operating member and said latch to prevent movement thereof, operating means operatively connected to said slidable member for positively operating said slidable member, and adjusting means for rotatably adjusting the slidable member relative to the operating member and the latch.-

14. In a circuit breaker, relatively movable contacts, an operating member for opening and closing said contacts, a latch member operable to cause opening of the contacts, a locking member movable transversely ofthe plane of movement of the operating member to a position to prevent contact opening movement of said Yoperating member and theY latch member, and adjusting means for adjusting the locking member in a direction substantially parallel to the plane of movement ofthe operatingmember for adjusting the'position of the lockingmember relative to the operating member and the latch member.

15. In a circuit breaker, relatively movable contacts, an operatingmember vmovable to cause opening and closing of said contacts, a latch member operable to cause opening of the contacts, a pivoted locking member movable transversely of the direction of movement of the operating member from anon-locking position to a locking position to prevent contact opening Vmovement rof said operating member and the latch member, manual actuating means for positively moving said-locking member to both positions including 'a rotatable pull-out knob, said knob being movable in the direction of its axis of rotation independently of said locking member, support means for said actuating means, and retaining means for said actuating means comprising a part on theknob engageable with recesses iny the support member for positively retaining said locking member in either position.

16. A circuit breaker comprising a base, relatively movable contacts, an operating member movable to anopen position and to a closed position 'for opening and closing said contacts, releasable means operable in response to predetermined conditions in the circuit controlled by the breaker for causing opening by said contacts'irrespective of the position of said operating member, said elements being mounted on said base, a slidable locking member movable in a path perpendicular to the path of movement of the operating member, a support for said locking'member rigidly mounted on said base, said locking member being movable from a non-locking position to a locking position in which portions thereof are interposed in the path of opening movement of said operating member and said releasable means to prevent opening movement of said operating member and to prevent operation of the releasable means.. y

17. A circuit breaker comprising a base, relatively movable contacts, an operating member movable to an open position and to a closed position for opening and closing said contacts, releasable means operable in response to predetermined conditions in the circuit controlled by the breaker for causing opening of the contacts irrespective of the position of the operating member, said elements being mounted on said base, a pivoted locking member mounted on said base and movable transversely of the direction of movement of the operating member, said locking member being movable from a non-locking position to a locking position between said operating member and said releasable means in which portions thereof are interposed in the path of opening movement of said operating member and said releasable means to prevent opening movement of said operating means and to prevent operation of the releasable means, and manually operable means for positively moving said locking member to both positions.

18. A circuit breaker comprising a supporting base, relatively movable contacts, an operating member movable to an open position and to a closed position for opening and closing said contacts, releasable means operable in response to predetermined conditions in the circuit controlled by the breaker for causing opening of the contacts irrespective of the position of the operating member, said elements being mounted on said base a locking member mounted on said base and movable in a path perpendicular to the path oi movement of the operating member, means for positively moving said locking member in both directions, said locking member being movable from a non-locking position to an intermediate position in Which a portion thereof is interposed in the path of movement of the releasable means to prevent operation of said releasable means, and said locking member being movable to a locking position in which said portion thereof and another portion thereof are interposed in the path of opening movement of said releasable means and said operating member to prevent operation o said releasable member and to prevent opening movement of said operating member.

19. A circuit breaker comprising relatively movable contacts, an operating member movable to open and close said contacts, means releasable to cause opening of said contacts irrespective of the position of said operating member, a locking member movable to a locking position wherein it blocks movement of said operating member in contact opening direction and prevents release of said releasable means, operating means for said lock-ing member including a manual member which is rotatable, said manual member being also movable in the direction of its axis of rotation independently of said locking member, support means for said manual member, and retaining means for said manual member comprising at least one projection on said manual member engageable with locking recesses on said support means.

20. In a circuit breaker having movable contacts,` an operating mechanism for effecting the engagement of said contacts with each other, means responsive to circuit conditions for elicoting the disengagementy of said contacts, a locking device for rendering said circuit responsive means ineffective to disengage said contacts, operating means for operating said locking device having a plurality of positions in one of which it operates said lockingvdevice to render said circuit responsive means ineffective and another position in which it positions said locking device to be ineiective on said circuit responsive means;

420 and means whereby said last mentioned operating means is operable from any one position to another position only by a composite of two different motions.

21. In a circuit breaker having movable contacts, an operating mechanism for effecting the engagement of said contacts with each other, means responsive to circuit conditions for eilecting the disengagement of said contacts, a locking device for rendering said circuit responsive means ineffective to disengage said contacts, operating means for operating said locking device having a plurality of positions in one of which it operates said locking device to render said circuit responsive means ineffective and another position in which it positions said locking device to be ineffective on said circuit responsive means; and means whereby said last mentioned operating means is operable from any one position to another position only by a composite of an axial and rotary motion.

22. In a circuit interrupter having engageable and disengageable contacts, a locking device for locking said contacts against disengagement, a handle operable on movement thereof in one direction to move the locking device into a plurality of selected positions; locking means engageable with said handle to prevent the movement thereof in said direction; said last mentioned locking means being disengageable on movement of said handle in another direction.

23. In a circuit breaker having contacts which engage and disengage, means responsive to circuit conditions for operating said contacts to disengaged position, a locking device having a plurality of positions, in one of which it is effective for locking said contacts in engagement, an operating means having a plurality of positions, in one of which it operates said locking device to its rst position and in another of said positions it operates said locking device to its second position, said operating means being rotated from one position to another of said positions, said operating means being movable axially at each of its positions for locking said member in its operated position.

24. In a circuit breaker having a pair of cooperating contacts Which engage and disengage, means responsive to circuit conditions for operating said contacts to disengaged positions, means for manually engaging and disengaging said contacts, a locking mechanism having a linear movement to a plurality of predetermined positions in one of which it is effective for locking said contacts in engagement. an operating member having a plurality of movements for passing between a plurality of set positions for operating said locking mechanism tov each of said positions, means for translating one of said motions of said operating member into linear movement for selectively operating said locking mechanism to one of its positions, and spring means for operating said operating member through the other of said movements for locking said operating member in positions, said spring means beingv effective to move said operating member through said other movement only at said predetermined positions.

25. A circuit interruptor having an operating arm and tripping mechanism; a locking device operable on longitudinal movement for engaging said tripping mechanism in one position to prevent operation of said tripping mechanism and for engaging said operating arm in a second po- 21 sition to prevent operation of said operating arm; an operating handle for said locking device; said operating handle being rotatable; a connection between said handle and said locking device for translating rotational movement of said handle 5 into longitudinal movement of said locking device.

GEORGE G. GRISSIN GER. TURE LINDSTROM. JEROME SANDIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 485,028 Binswanger Oct. 25, 1892 1,678,129 Tuttle July 24, 1928 10 2,288,270 Dorfman et al June 30, 1942 2,177,014 Austin Oct. 24, 1939

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