US2849565A - Short time delay defeater during closing stroke of circuit breaker - Google Patents

Description

Aug. 26, 1958 F. J. POKORNY 2,849,565

SHORT TIME DELAY DEFEATER DURING CLOSING STROKE 0F CIRCUIT BREAKER Filed July 22, 1954 5 Sheets-Sheet l Aug; 26, 1958 F. J. POKORNY 2,849,565

SHORT TIME DELAY DEFEATER DURING CLOSING STROKE 0F CIRCUIT BREAKER Filed July 22, 1954 5 Sheets-Sheet 2 J1 (En 44 IN V EN TOR.

Aug. 26, 1958 F. J. POKORNY 2,849,565

SHORT TIME DELAY DEFEATER DURING CLOSING STROKE 0F CIRCUIT BREAKER 5 Sheets-Sheet 3 Filed July 22, 1954 INVENTOR. kfl/VK dear/w awn/en's F. J. POKORNY 2,849,565

SHORT TIME DELAY DEFEATER DURING CLOSING STROKE OF CIRCUIT BREAKER Filed July 22, 1954 5 Sheets-Sheet 4 Aug. 26, 1958- 07 52a 50 I. INVEN TOR.

Fen/v; Josip/r lame/Yr F. J. POKORNY 4, 6

Aug. 26, 1958 SHORT TIME DELAY DEFEATER DURING CLOSING STROKE OF CIRCUIT BREAKER 5 Sheets-Sheet 5 Filed July 22, 1954 ZZZ L:J- B

IN V EN TOR. Haw/vie losefeale/v Y United States Patent Ofice 2,849,565 Patented Aug. 26, 1958 SHORT TllVlE DELAY DEFEATER DURING CLOS- ING STROKE 0F CmCUIT BREAKER Frank Joseph Pokorny, Hatboro, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa, :1 corporation of Pennsylvania Application July 22, 1954, Serial No. 445,094

6 Claims. (Cl. 200-38) My invention relates to selective trip circuit breakers and is more particularly directed to a novel arrangement to permit instantaneous trip-free operation of the interrupter when it is closed on a fault. My invention is related to novel means to enable a time delay circuit breaker used in a selective trip system to instantaneously trip open when it is manually or automatically closing on a fault and is an improvement of the arrangement shown in Patent No. 2,536,775, issued January 2, 1951, to William M. Scott, Jr., entitled Circuit Breaker Tripping Mechanism, assigned to the assignee of the instant appli cation.

Selective trip systems such as described in Patent No. 2,648,803, issued August 11, 1953, to Joseph Wood, entitled Cascaded Breaker System, assigned to the assignee of the instant application, Patent No. 2,486,602, issued November 1, 1949, to Otto Jensen et al., entitled Timing Device, assigned to the assignee of the instant application and are provided with circuit breakers of the type shown in Patent No. 2,439,165, issued April 6, 1948, to H. C. Graves, Jr., entitled Selective Tripping of Circuit Breawers in a System, assigned to the assignee of the instant application having time delay characteristics for all current values up to the interrupting capacity of the circuit breaker. Thus, except for severe short circuit currents, the circuit breaker always opens with either long or short time delay characteristics.

These circuit breakers can properly protect the system when fault or short circuits occur. When the circuit breaker is latched in the closed posit-ion the short and long time delay tripping will not harm the interrupter or the system during the period of the time delay. However, if a fault exists on the line at the time when an attempt is made to automaticaly or manually close the circuit breaker, the circuit breaker may be severely damaged.

That is, the magnetic forces set up in the loop consisting of the movable contact will tend to force the contacts to their open position and since this force may be larger than the force tending to close the breaker the mechanisms will move to the open position.

Thus, if the circuit breaker is provided with time delay characteristics the trip latch is not set and hence the circuit breaker is not trip-free. That is, if the closing force is not sufiicient to close and latch the contacts against the fault line then the opening of the breaker will not be trip-free.

This may result in either injury to the person attempting to manually close the breaker or in pumping operation of the breaker, if it is being automatically closed.

It is also noted that if the contacts do not latch when the circuit breaker is closed on a fault line, the arcing contacts may remain in engagement or chatter, thus causing excessive damage to the components of the circuit breaker. That is, since the arcing contacts may remain in engaged position until the time delay for the overcurrent armature has run out, the arcing contacts will be damaged since they are not designed to carry current for any appreciable length of time.

This undesirable condition cannot be overcome by merely providing more closing force to overcome the magnetic opening forces. The reason for this is that the closing forces are applied whether or not a fault exists on the line.

If sufficient closing forces were provided to close and latch the circuit breaker against the fault, then a closing operation with this force, in the absence of a fault, would cause undue mechanical strain on the breaker.

in order to overcome this undesirable condition, I have removed the time delay of the trip coil during the opening operation of the circuit breaker by rotating the timer arm out of the path of the overcurrent armature during the opening operation of the circuit breaker, and restore same only after the contacts are engaged and latched. Thus, the circuit breaker has instantaneous trip characteristics only during the closing operation. That is, the circuit reaker will have high speed trip characteristics during the closing period and time delay characteristics after the circuit breaker is closed and latched.

With this arrangement if an attempt is made to close the interrupter on a fault line the trip latch will be released as soon as fault current commences to flow even though the prop latch is not moved to latch position. Thus, trip-free operation will occur as a result of the instantaneous tripping.

Hence, with this arrangement there will be no kick back forces on the manual closing means or on the automatic closing means, or damage to the arcing contacts as a result of an attempted closing on a fault line.

it will be noted that there are several other novel methods to achieve the above noted desired results. For eX- ample, co-pending application Serial No. 445,123, filed July 22, 1954, assigned to the assignee of the instant application, provides an instantaneous armature which is normally blocked to prevent operation thereof. However, it is blocked during the opening operation to permit instantaneous trip if the circuit breaker is closed on a fault line. Co-pending application Serial No. 445,122, filed July 22, 1954, assigned to the assignee of the instant application, provides a latch for the pivot of the timer housing which is unlatched during the opening operation so that the circuit breaker will trip-free without time delay if closed on a fault line. Co-pending application Serial No. 445,124, filed July 22, 1954, assigned to the assignee of the instant application, provides an arrangement wherein the entire timer housing is rotated during the opening operation to render the time delay means ineffective when the circuit breaker is closed on a fault.

Accordingly, a primary object of my invention is to provide a novel arrangement for selective trip circuit breakers wheren high speed or instantaneous tripping occurs for any magnitude of overcurrent only during the closing operation of the circuit breaker due to the rotation of the timer arm during the opening operation and thereafter when the circuit breaker main contacts are engaged has time delay characteristics.

Another object of my invention is to provide a novel arrangement in which the time .delay of the tripping mechanism is rendered inoperative during the opening operation of the circuit breaker due to the rotation of the timer arm and is not restored until after the contacts are engaged and latched.

A still further object of my invention is to provide novel means to remove the time delay escapement timer arm from the trip armature when the circuit breaker is open and to maintain said timer arm removed from said trip armature until the contacts are closed and latched.

These and other objects of my invention will be apparent from the following description when taken in connection with the drawings in which:

Figure 1 is an exploded perspective view of an operating mechanism of a circuit breaker and shows the cooperating contacts in a disengaged fully open position. This figure illustrates my novel device wherein the time delay means for the trip armature is rendered ineffective when the circuit breaker is in the open positionby rotating and latching open the timer arm and remains ineifective until after the contacts have closed and latched.

Figure '2 is a side view of the circuit breaker of Figure 1 and illustrates the position of the various components when the cooperating contacts are in a fully closed position. This figure also illustrates the manner in which my novel means releases the timer arm after the contacts have closed and latched so that subsequent automatic tripping of the circuit breaker will occur with time delay;

Figure 2A shows a modified form of the timer element shown in Figure 2.

Figure 3 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the fully closed position of Figure 2. This figure illustrates the latched position of the trip latch and prop latch.

Figure 4 is a schematic view of the circuit breaker of Figures land 2 and illustrates the initial trip position.

Figure "5 'is a schematic view of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the collapsed position, prior to the relatching of the trip latch. Figure 6"is a schematic view of Figures 1 and 2 illustrating the position of the components when the circuit breaker is in the fully open position of Figure 1 with the trip latch re-engaged.

Figure'7 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the circuit breaker in'the trip-free position. This figure also illustrates the latched control relay and closing solenoid which comprises the automatic closing means for the circuit breaker. This figure further illustrates my novel means to render the escapement device ineffective until after the contacts have latched closed.

V Figure 8 is a view in perspective, partially broken away, Of the complete long and short time delayed trip armatures and control means thereof.

Figure 9 is a sectional view of the short time delay mechanism taken in the direction of the arrows 99 of Figure 11.

Figure 10 is a View, partly in section, of the short time delay mechanism taken in the direction of the arrows 10-10 of Figure 9.

Figure 11 is a view, partly in section, of the short time delay mechanism taken in the direction of the arrows 11'11 of Figure 9.

Figure 12 is a side view of the run off pinion and shaft of the short time delay mechanism of Figure 8.

Figure 13 is a side view of the run 01f gear assembly ofthe'shorttime delay mechanism of Figure 9.

Referring to the figures on the occurrence of an over current condition, an energized coil 139 aided by the core 141 has a screw 145 threaded at one end thereof and which is used to efiect an adjustable contact with the initial tripping member 140. The head 144 of the screw 145 acts to rotate bar 140 upon the energizing of the coil 139'by its extension plate 146 which is bolted to the shaft 140. When the head 144 hits the end of "the extension plate 146, the shaft 140 is caused to rotate in a counterclockwise manner looking from the right of the circuit breaker 30, which is the view of Figure 1.

The speed of the armature 142 of the overcurrent trip coil 139 is controlled by the timer arm 5% which is pivoted on shaft 514 of the timer mechanism. The timer arm 500 is secured to the short time delay escapement mechanism which is identified by the numeral 73 in Patents 2,769,057, issued October 30, 1956, to Carl Thumim, entitled Time Delay Circuit Breaker, and 2,704,311, issued March 15, 1955, to Carl Thumim, entitled Time Delay Circuit Breakers, assigned to the assignee of the instant application. I

The short time delay escapement mechanism for the timer arm 5% may be identical to that described in the above identified co-pending applications and forms no part of the instant invention.

However, a brief description of this unit will be given so that a complete understanding of how the rotation of timer arm 5% during the opening operation of the circuit breaker serves to defeat the short time delay for the overcurrent trip arrnature 142;

Basically the short time delay mechanism 73 shown in detail in Figures 8 to 13 inclusive is a mechanical escapement mechanism having a-verge'26 Whichcontrols the speed of rotation of the-timer arm or lever 500. Timer arm 5% bears against the lower extension of the short time armature 142 so that when the short time armature 142 moves from the full open position of Figure 2 to the tripping position and before it. completes its full trip movement (dotted view of FigureZ), it must rotate the timer arm 500 in a counterclockwise direction as the armature 142 is rotated in a clockwise direction.

The armature 142 cannot rotate toward tripping position without rotating the timer arm 500 in a counterclockwise direction. The escapement mechanism is in the short time delay housing 73 and secured to the timer arm 500 through the shaft 514. 1 Hence, the escapement mechanism 73 controls the speed of movement of the armature 142 in its movement toward the trip position of the circuit breaker.

The escapement mechanism, as seen particularly in Fig ures '9 to 13, is comprised of a housing 73, a shaft 514 extending therefrom. The timer arm 5% is mounted on one end of the shaft 514. The other end of shaft 514 carries'a segment gear 11 and a plate 12 (see also Figure 13). Segment gear-11 meshes with pinion 17 which is provided with a recess 13 (see also Figure 12) registering with the shrouding .plate 12. As the shaft 514- is turned, the segment gear 11, which meshes with the pinion 17, rotates pinion 17' until the segment gear 11 escapes from the'pinion 17. The shrouding plate 12 is recessed at 14 below the level of the teeth 15 of the segment gear 11 so that it does not interfere with the meshing engagement between teeth 15 of segment gear 11 and the teeth of pinion 17.

After the full time delay has been achieved, it is necessary that the armature escape the time delay mechanism. At this time the shrouding plate 12, and particularly por' tion 16 thereof, comes intoregisterwith the recess13 of the pinion 17, thereby holding the pinion 17 stationary while the shrouding plate. 12 and the shaft 514 may rotate readily with respect thereto. 5 i

The segment gear 11 is'cut away at .18 so thatit will not obstruct the movement of segment gear 11 at this run 01f position. 1 1 Consequently, the movement'of teeth-15 of the segment gear 11 during the initial movement of the armature is time delayed thereby delayingthe'rotation of the timer armSW and resulting in a' time. delay for the armature 142. However, when the armature reaches the half-way point the segment gear 11 disengages tooth engagement with pinion 17 permitting an unrestrained stroke of the armature 142 to engage with tripper bar 146 with a hammer blow. ..v

In order toavoid. misalignment between the parts of the escapement mechanism, the engagement of the rai i.- portion 16 of the shrouding plate 12in the recess 11, '"i the pinion 17 holds the pinion 17 and the associa mechanisms, hereinafter described, in the position they held at the time the teeth *15 of gear segment 11 lift portion 17 so that during the return movement when teeth 15 engage the pinion 17-the relationship between teeth 167, the raised portion In of shrouding plate 12 reestablishes mesh engagement of the'teeth of segment gear 11 and the teeth of pinion gear 17.

Thus, in order to achieve the short time delay, it is necessary to selectively delay the rotation of the pinion 17. Pinion 17 is carried on shaft 19 which carries the gear 20. Gear 20 meshes with gear 21 on shaft 22 which carries the gear 34. Gear 34 meshes with gear 23 on shaft 24 which carries the toothed escapement rack 25.

Verge 26 rotatable on pin 27 has appropriate teeth 28, 29 which alternately engage with the teeth of escapement Wheel and limits its speed of notation by the speed with which the teeth 28 and 29 of the verge 26 can successively escape the wheel 25 by oscillation of the verge 26. The planes of the teeth of the escapement wheel 25 are so oriented that the direction of the force lines between wheel 25 and verge teeth 28 falls outside of verge pivot 27 by a definite amount. The resulting movement causes the speed of oscillation to verge 26 to vary in direct proportion to the magnitude of the force impressed on it by wheel 25.

Thus, as has been pointed out, the rotation of armature 142 to the trip position causes its end to rotate the timer lever 580 of the short time mechanism 73 which is secured to the shaft 514 and which, through the mechanism above set forth, operates the timer mechanism to effect short time delay in restraint of clockwise rotation of armature 142. The greater the force executed by armature 142, the greater the speed of oscillation of verge 26 and the shorter the time delay.

The entire time delay housing 73 is mounted on a shaft which is in threaded engagement with threaded section 33 in wall 35 of the housing 73. The housing 73 may be rotatably adjusted wherein a greater or less number of teeth of the gear segment 11 must pass in engagement with the pinion 17 before the run-oft condition is achieved, wherein extension 16 of the shrouding plate 12 passes freely, through the recess 13 of the pinion 17 while the recess 18 in the gear segment 11 permits free rotation of the gear segment 11 past the pinion 17.

The short time delay armature 142 is used for the purpose of obtaining a short time delay expressed in cycles for currents exceeding a given minimum value. This is in contrast to the long time delay armature 42 (Figure 8) which is used for the purpose of obtaining a long time delay expressed in seconds or in minutes for current values in the recognized range of overcurrents and also for the purpose of obtaining an instantaneous trip for short circuit or other high values of fault current.

The instant invention is directed to means to remove the timer arm 500 from the path of movement of the overcurrent relay armature 142 during the manual or automatic closing of the circuit breaker. Although the circuit breaker per se with which my novel arrangement may be coordinated, forms no part of the instant invention, a description of the operation of the unit will now be given in order to understand the cooperation between the components of my invention and the operation of the circuit breaker.

The shaft 140 is caused to rotate by means of the shunt trip coil 150 which upon being energized pulls an armature member 151 to it. The member 151 has a link 152 rigidly attached to one end of member 151 by means of an angle 154. The link 152 is attached to the angle 154 by means of a threaded portion 199 of link 152 I which enters the angle 154 and a nut 148. The angle 154 is movably attached to the member 151 by means of a pin 155. A restoring spring 147 attached to the member 151 resets the armature upon de-energization of the coil 150.

The link 152 is attached to the shaft 140 by means of another angle 156. The angle 156 is attached to the shaft 140 by means of bolts passing through holes 161 in angle 154 and shaft 140 and to the link 152 by means of a cap 160. The cap 160 is movably attached to the link 152. Thus, the shaft can now be caused to rotate by two methods, one due to the energization of the overcurrent trip coil 139 and the other due to the energizing of the shunt trip coil 150. The coil is remotely caused to be energized and is usually accomplished by manual operation of a remote push-button switch. The rotation of shaft 140 causes a link 162 to be moved by means of an angle 163 which is bolted to the shaft 140. The angle 163 has an indentation 165 near the farthest edge 166 from the shaft 148. The link 162 has two slots 168 and 167. The slot 167 engages the indentation 165 of angle 163.

The translatory movement of link 162 causes the rotation of a milled shaft 170. The milled shaft 170 has another angle 171 rigidly attached to it by means of two bolts 172. This angle has an indentation 173 'near the end 174 which is farthest from the shaft 170. The indentation 173 of angle 171 engages the slot 168 of link 162. Thus, the rotation of shaft 140 causes the rotation of milled shaft 170. When milled shaft 170 rotates to release a latch 177, as is hereinafter described, the circuit breaker movable contacts 60, 61 are allowed to be disengaged from the stationary contacts.

The angle 171 described above has an abutment 178.

This abutment 178 is engaged by a roller 179 which is rotated manually by means of the closing handle 184 attached to the shaft 180. Shaft 180 has a crank 181 which is rigidly attached to the shaft 180 by means of a screw 182. The roller 179 is rotated by the closing handle 184, the roller 179 engages abutment 178 of angle 171 and rotated milled shaft 170. Thus, milled shaft 170 can be made to rotate by a plurality of methods to open the circuit breaker 31?. It can be made to rotate manually by means of closing handle 184; it can be made to rotate by means of an overcurrent condition in trip coil 139 and it can be made to rotate by means of an excitation of shunt trip coil 150, as described above.

The latch 177 is an integral part of the trip arm 185. The latch 177 engages the milled shaft 170 so that a small revolution of shaft 170 releases the latch 177, as hereinafter described. The shaft 170 is milled slightly past center at 186. The trip arm 185 is pivoted at 187 on a long pin 188. The pin 188 is also engaged on the trip arm extension 189 at point 183. The movable arm 190 is pivoted on pin 188 and extends beneath a roller 193. The roller 193 is the pivot point of a toggle mechanism consisting of two links 194 and 195 and is carried by a pin 202 which pivots the meeting of links 194 and 195 which are each comprised of two arms. Arms 194 are pivoted on floating pin 196 and arms 195 are pivoted on pin 204.

The arms 194 support a rod 197 at 198 and 199, respectively. The rod 197 carries one end of a restoring spring 203 which is tensed by means of a stationary shaft 212. The restoring spring 283 exerts a tension on the link 194 which tends to open or break the toggle mechanism. Link 194 is pivoted on a floating pin 196, which is supported by link arm 185 and its extension. 189, being parallel to the pin 188. The other link 195 of the toggle is pivoted on movable link 2110 which is connected by means of an adjustable insulator 201 to the movable contact assembly 61 and pivoted on contact bar 406.

When the toggle mechanism consisting of links 194 and 195 is straightened but by means hereinafter described, pressure is put on movable link 200 by means of link 195 and bearing pin 204. The movable link 2% is pinned to insulator 201 by pin 205 and moves so as to advance the insulator 201 and the movable contacts 61 towards the stationary contact 60.

In the exploded view shown in Figure 1, the contacts are open and the toggle mechanism consisting of links 194 and 195 is collapsed. The circuit breaker may be closed by a variety of methods. The circuit can be closed manuallyby means of shaft 180 rotated by closing handle 184, described above. If shaft 180 is rotated in the direction indicated by the arrow 184A, the roller 179 will engage the bottom of arm 190 and force the arm 196) against roller 193, thus straightening out the toggle mechanism and closing the circuit breaker contacts. The movable links 201) are under an opening tension by means of opening spring 210 so that if no additional locking action other than described above for supporting the toggle existed, the circuit breaker would reopen immediately upon releasing the shaft 180. The locking device is supplied by means of a crank 211 which is located on a shaft 212 mentioned above, Whose longitudinal axis is parallel to the axis of the milled shaft 170, and the rod 140. The crank 211 has two arms 213 and 21.4. The latch 213 is located, when the circuit breaker is open, adjacent the roller 193. When the roller 193 is forced upward, as due to the pressure of arm 19 41, the roller pushes against arm 213 of crank 211, rotating the crank211 slightly on shaft 212. When the roller 193 has cleared the top of latch 213, the prop latch 213 snaps underneath the roller 193 due to the compression of a spring 220. The spring 220 which is wound on the shaft 212 has one end on an indentation 221 of crank 211 the other end borne against a shaft 222 which pierces the trip arm 185. The shafts 212 and 222 have been moved out of position in the exploded view for the sake of clarity. Actually, the shaft 222 pierces the trip arm 185 at point 207. The longitudinal axis of shaft 222 is essentially parallel to the longitudinal axis of shaft 212 and milled shaft 170.

When, the roller 193 is moved, straightening the toggle, it causes crank 211 to rotate compressing spring 229. The roller clears the top of prop latch 213 letting the crank rotate in the opposite direction until'the 213' is directly beneath and supporting the roller 193. The other arm 214 of crank 211 bears against the shaft 222 preventing further rotation ofthe crank 211 so that the arm 213 is stopped directly beneath the roller 193. The spring 220 is under compression normally so that the arm 214 is constantly bearing against the shaft 222. When the toggle is straightened, the rotation of the crank 211 moves the arm 214 away from the shaft 222 until the roller 193 clears the top of prop latch 213. Then the reverse rotation of the crank 211 occurs until the arm 214 again bears against shaft 212.

Thus, when the toggle is straightened and the circuit breaker closed, the crank 213 locks thetoggle 194-495 and thus locks the circuit breaker in a closed position.

The closing handle 184 by means of the shaft 131 after closing the circuit breaker by means of the rotation of roller 179 against the arm 1%, as described above, is returned to its normal position by means of a crank 230. The crank 230 is pivoted on a stationary pin 231.

The crank 181 described above has an indentation 232 which meets a roller 233 of crank 230. The crank 230 supports a pin 234 which has a restraining spring 235 engaged at one end 236. The restraining spring 235 is at tached to an angle 237 and is tensed on the pin 235. causing the crank230 to rotate. The rotation of crank 230 causes the roller 233 to meet the indentation 232 returning the crank 181 to its normal position.

The various positions of the operating mechanism are shown in Figures 3 through 6.

Figure 3 shows the closed position thereof, with link 195 pushed forward to raise the crank 200 and close the insulator 201 and contact arm 78 and with the roller 193 on the prop latch 213.

The latch arm 185 is shown in appropriate latching engagement with the milled shaft 179.

When the shaft 140 described above, is turned to release the mechanism or on the occurrence of tripping conditions, the milled shaft 170 is rotated to permit the latch arm 185 to move into the milled section 136 o the milled shaft 170, as seen in Figure 4.

8 Then as seen in Figure 5, the roller 193 dropsotf-the prop latch abutment 213 to open the circuit breaker.

Thereafter, as seen in Figured, the latch airm lis restored to its initial position and the milled shaft is restored to latching position-so that the circuit breaker may again be manually moved from the open position of Figure 6 tothe closed position of Figure 3 by'han'dle-180;

The circuit breaker may also be automatically closed by means of the latched control relayl1aving-coil-300 and armature 301 and the closing solenoid 241 which controls the closing plunger 240. i

The circuitry for the automatic closing means-is shown in Figure 7 and me details of the latched relay 'and'closing solenoids are seen in Figures 1 and 7. A detailed description of the operation of the closing means shown in these figures is set forth'in Patent'2,792,534, issued May 14, 1957, to Carl Thumim, entitled Solenoid Control Relay for Circuit Breakers; copending application Serial No; 254,349 filed November 1, i 1951; Serial No. 383,714 filed October 2, 1953 by Carl Thumim, entitled Circuit Breaker Anti-Pumping Device; Patent 2,832,917 issued April 29, 1958, to Challis I. Clausing, entitled Anti- Pumping Closing Means for Circuit Breakers; and copending application Serial 'No." 428,638 filed May 10, 1954, all of which are assigned to theassignee of the instant application.

' Figure 7 also illustrates the trip-free operation of-the circuit breaker. Thus, for example, when the breaker is automatically closed by means of the control relay 300- 301 and the closing solenoid 241L441, the circuit breaker then will trip-free providing-the above described -trip latch 170 is opened as soon as fault current flows through the contacts. That is, even though a continuous closing force may be applied to the breaker from the'cl'os'ing plunger 240 the circuit breaker will nevertheless trip-free, if the trip latch 170 is rotated.

As heretofore noted, the trip latch 170'may be c'ontrolled by the over current'short time delay relay 139 142. However, as heretofore noted the breaker to which my invention is adapted is provided with an escapement type time delay'for the operation of the armature 142.

Hence, if'an attempt is made to either'automatically close the breaker by means of the plunger 240 or'manually close thebreaker by means ofthe handle 184 on a fault line, the magnetic'forces' would tend to separate the cooperating contacts 60, 61.

The opening magnetic forces on cooperating contacts 60, 61 may be greater than the closing force which'is derived from the energy flowing in the closing solenoid 241 or may be greater'than the force derived when manually closing by handle 184. In' this case the circuit breaker contacts 60, 61 will separate clue to the magnetic forces, but the trip latch 170186 will remain'engaged since there is a time delay on the armature 142 which controls the position of the trip latch. It is also possible that only the arcing contacts of the circuit breaker will engage, and remain in engagement since there is air-insufiic'ient force to' close the circuit breaker, against a fault thereby damaging the contact and the circuit breaker.

Hence, the components will attempt to assume" the position in Figure 6. However, since a closing force will be continuously applied, thereby driving the plunger 240 upwardly, a secondattempt will'be made and the above noted operation will be repeated. Hence, there will be chattering or pumping of the cooprating contacts which will result in damage to the circuit breaker and line to be protected thereby.

Since the circuit is constantly being made and broken the armature 142 of the trip coil relay 139 will always moved back to its neutral position, as seen in Figure 2. That is the current will not be permitted to flow for a sufficient length of time to allow the armature 142 to move from its energized position against the time delay created by the timer arm 500.

It is a primary object of my invention to provide means to remove the timer arm 500 during the opening operation from the path of movement of the trip relay arm 142 so that the trip latch will instantaneously be operated by the armature 142 when the circuit breaker is closed on a fault line. That is, if the contacts 60, 61 are moved toward the engaged position and fault current starts to flow, even though the prop latch 213 is not latched, the trip armature 142 will be allowed to move to its energized position without intentional time delay to thereby result in an instantaneous trip of the breaker. Hence, the circuit breaker will trip-free as noted in Figure 7. If the circuit breaker is closed on a normal line, then the timer arm 500 is allowed to assume its neutral position as seen in Figure 2.

I achieve the above noted desired results by providing a mechanism which is operative to remove the time delay means from the trip armature 142 whenever the circuit breaker opens. That is, if the circuit breaker is opened due to the time delay trip, to the overcurrent trip relay 139 or manually opened by means of the handle 184 or through the shunt trip means 150, the novel means of my invention will render the time delay ineffective.

Furthermore, the novel means will insure that the time delay remains inefiective until after the contacts have closed and latched to thereby insure instantaneous tripping whenever the circuit breaker is closed on a fault circuit.

The novel mechanism of my invention is operated from the contact bar 406. The contact bar 406 rotates with the toggle mechanism 194*195 of the circuit breaker. Hence, when the circuit breaker is in the fully closed position of Figure 2 the contact bar 406 will be in the position illustrated.

However, when the circuit breaker is moved to the 3 fully opened position of Figure 1 the contact bar 406 will be rotated in a counterclockwise direction to the position illustrated in Figure l.

The position of the contact bar 406, when the contacts are in an open and closed position, may also be seen in the schematic diagrams of Figures 3 through 7. Since the contact bar 406 is an indication of the position of the cooperating contacts, I have provided an arrangement which is controlled from contact bar 406 to operate the timer lever 500, as best seen in Figures 1 and 2.

Bell crank 501 is rigidly secured to the contact bar 406. A tie rod 502 has one end pivotally secured at 504 to arm 503 of the bell crank 501 and the opposite end is pivotally secured at 506 to the lever 507.

The tie rod 502 is threadedly engaged in its extension members 508, 509 so that the linkage can be properly adjusted, as to length, to achieve proper timing of the operation. The lever 507 is pivoted at 510 and carries member 511 which is pivotally connected thereto at 512.

The timer arm 500 is mounted on shaft 514 of escaper ment timer 73 and has three extending arms 515, 516 and 517. The time arm 500 is comparable to the timer arm 72 of Patents 2,704,311 and 2,769,057 and its control by timer 73 has heretofore been described.

The escapement mechanism 73 which controls the timer arm is fully described and claimed in the above identified co-pending applications.

The arm 515 of the timer arm 500 has a pin extension 518 which rides in the elongated slot 519 of the extension 511. A reset spring 520 is secured at one end to to the armature 142 and at the opposite end to the latch arm 516 of the timer arm 500.

It will be noted that since the armature 142 is pivoted at 521 the reset spring 520 will maintain the armature 142 in the neutral position seen in Figure 2.

The arm 517 of the timer arm 500 is provided with a roller 522 which is positioned in the path of the armature 142. Thus, when the overcurrent trip coi1'139 is energized by fault current it will tend to attract the armature 142 from the neutral position of Figure 2 to 10 the energized position of Figure 7 (also dotted position of Figure 2.)

However, in order for the armature to move through this clockwise path around the pivot 521 it will have to move the timer'arm 500 counterclockwise around its pivot 514. Since the movement of the timer arm 500 is controlled by the escapement means 73 as heretofore described, the movement of the armature 142 from its neutral position to its energized position will be time delayed.

As heretofore noted, it is desirable to remove the timer arm 500 from the path of movement of the trip armature 142 when the circuit breaker is in the open position so that there will be instantaneous trip whenever the circuit breaker is closed on fault.

The mechanism 501502507-511 achieves this in the following manner. Whenever the circuit breaker is moved to the open position by either manual 184, automatic 139 or shunt trip means the contact bar 406 will be rotated in a clockwise direction.

Hence, the crank 501 will be rotated clockwise to move the tie rod 502 downwardly. The downward movement of the tie rod 502 will rotate the crank 507 clockwise to its fixed pivot 510 to thereby lift its extension 511. Since the elongated slot 519 of the extension 511 surrounds extension pin 518 of the timer arm 500 the timer arm will be rotated in a counterclockwise direction about its pivot514 to the position as seen in Figure l.

The position of the armature 142 in Figure 1 illustrates: the position of the armature when the overcurrent coil 139 is not energized by fault current. Hence, as is best seen in Figure 1 the timer arm roller 522 is removed from the path of the armature 142. That is, the armature 142 can now move from the neutral position, illustrated in Figure l and Figure 2, to its energized position shown by the dotted line of Figure 2, without engag ing or coming in contact with the timer arm 500.

Thus, it will be noted, that whenever the circuit breaker is in the open position the timer arm 500 is rotated in a counterclockwise position to remove same from the path of movement of the armature.

However, it is also desirable to insure that the timer arm 500 remains ineifective until after the cooperating contacts 60-61 have been moved through the initial engaged position and the prop latch 213 is moved to its latch position or final engaged position. Thus, additional means must be provided to maintain the timer arm 500 in its extremely counterclockwise position even though the linkage 501-502507-511 is initially moved toward the closed position when the contact bar 406 is rotated in a counterclockwise direction due to the closing of the contacts.

Latch 5223 comes into engagement with the latch extension 516 of the timer arm 500 to insure this sequence of operation. The latch 523 which has a fixed pivot 524 is biased in a clockwise direction by the spring 525, which is secured at one end to the fixed pin 526 and at the opposite end to one arm of latch 523.

The latch 523 is also provided with an extension 527 which extends perpendicular to the main portion of the latch 523 and is positioned above by adjustment screw 528. The adjustment screw 528 is carried by the lever 507 in an engaged position. Thus, latch 523 is held in the inoperative position indicated due to the engagement of its extension 527 with the adjustment screw 528;

That is, the latch 523 is not rotated to its extreme clockwise position by the spring 525 due to the obstruction in its path of movement by the adjustment screw 528. Thus, in a position indicated the timer arm 500 can be rotated through its full counterclockwise movement, 'with time delay, by the overcurrent armature 142.

However, when the cooperating contacts 60, 61 are moved to the open position and lever 507 is thereby rotated in a counterclockwise direction, the adjustment the-lever .507 also-causes counterclockwise rotation of the timer arm 500-dueto engagement of pin 518 in slot 5:19;: Hence, when: the contacts are inthe open position indicated in Figure 1, the latch 523 will engage the latch extension-516 of the timer arm. 500 to thereby maintain itin extreme counterclockwise position. which is out at thepath of movement, of the trip-armature 142.

.iEhe; screw. 528; is adjusted. with respect to the movement of the contactbar 406so that the. latch 523 is not rotated to. release the. timer arm 500 until after the contactsqfl, 6-1 have engagedandthe prop latch 213 is moved intoits latch: position.

..Afterthe.contactshave been engagedand latched the screw 528 will engage the extension 527 of the latch to thereby-rotate this member in acounterclockwise direction around its pivot;524-,- and to therebyrelease the timer arm Stitland allow it to rotate, ina counterclockwise direst-ion undcnthe: influence of its reset spring 520. Thus, it will be notedthatthe reset-spring 520 serves to both reset the trip-armature. 142. and the timer arm 500. In this position-the; timer mm 500 will again be effective totdelay operation. of the armature 142.

In the drawings I have shown my invention in connection. with! one pole of a; circuit=breaker 30. However, it will be-apparent to those skilled in the. art that shaft 510 can extend pasteach pole of a multipole circuit breaker so thatthemontrol of the timer lever 500 is identical for each strip unit.

lt:.will be. notedthat the control shaft 510 may be provided with time delay means so that the escapement timer 73 isznot rendered operative-until after the contacts 60', 61 havelatohed closed. Thus, asseen in Figure 2A the-shaft 5l tl has air-arm 5310A rigidly secured thereto. An escapement' means 73A, which may be similar to escapement 73 describedin connectionwith Figures 9 to 13, has a timer arm 500Az-which. is. positioned to be in the path of movem nt of the arm 519A. Hence, the clockwise rotation of theshaft 510*.will be time delayed by the. timer 73A and timerarm. 500A so that the circuit breakenwillnot' have. time delay characteristics untilafter the maincontacts 6t filhave latched closed.

It will be noted that in theusual installation of a circuit breaker of the type described to be used in a selective system the circuit breaker is provided with two armatures. One of them is for long time delay and the other. oflwhich is for shortstime delay. As a rule the long time delay is achieved by means of; a dash pot and the short time delay is achieved by means of an escapement mechanism.

-The. structural arrangement for the dual armature of theovercurrent coiliand the time delay, therefore, is shown. in. Figure 8 and clearrly set forth in Patents 2,704,311 and 2,769,057.

In the: foregoing, I haye-described my invention only in connection with: preferred embodiments thereof. Many variations. and modifications of the principles of my invention within the; scope of the description herein are obvious. Accordingly, Iprefer to be bound not by the specificdischarge herein, but only by the appended claims.

I claim:

1. Ina circuit breakerhaving a pair of cooperating contacts. with an. initial engaged, a final engaged and a disengaged position, and a time delayed overcurrent trip means, said overcurrent time delay trip means being comprised of an armature, an overcurrent coil to control the movement of said armature a timer mechanism and a. timer arm;v said timer arm. positioned in the path of movement of said armature to delay the movement thereof when said coil is energized by an overcurrent,

means operatively connected to said timer arm and said circuit breaker to remove said timer arm from the path of movement of said armature when said circuit'b'reaker contacts are moved from said final engaged to said disengaged position; said'means effectiveto maintain said timer arm in said removed position while said circuit breaker contacts are being moved from said disengaged to said initial engaged position, said means efiective to release said timer arm to thereby permit said-arm to be moved into the path of movement of said armature when said contacts are in said final engaged position.

2. In a circuit breaker having a pair of cooperating contacts with an initial engaged, a final engaged and a disengaged position and a time delayed overcurrent trip means, said overcurrent time delay trip means being comprised of an armature, an overcurrent coil to control the movement of said armature, a timer mechanism, and a timer arm; said timer arm and said armature each having a first and second position, said armature operatively positioned to cause said contacts to move from said final engaged to saidv disengaged position when said armature is moved from said'first to said second position, said timer arm interposed in the path of movement of said armature when said'arm is in said first position, said timer arm positioned outside the path of movement of said armaturewhen said arm is insaid second position, means operatively connected to said timer arm and said circuit breaker to move said arm from said first position to said second position when said'contacts are moved from said engaged to said disengaged position, said. timer arm biased and moved to said first position after said contacts are moved from said initial engage position to said final engaged position.

3. In a circuit breaker having a pair of cooperating v contacts with an initial engaged, a final engaged and a disengaged position and a time delayed overcurrent trip means, said overcurrent time delay trip means being comprised of an armature, an overcurrent 'coil to control the movement of said armature, a timer mechanism, and

.a timer arm; said timer arm having biasing means to bias said arm to a first position in the path of movement of said armature, first means operated by said circuit breaker when said contacts are moved from said final engaged position to said disengaged position to move said timer arm to a second position against the force of said bias and out of the path of movement of said armature; a second means to maintain said timer arm in said second position while said circuit breaker is in said disengaged and initial engaged position, said first means I operatively positionedto render second means ineffective after said contacts have been moved from'said disengaged position to 'said final engaged position.

4. In a circuit interrupter having trip means and cooperating contacts with an initial engaged, a final engaged and a disengaged position, time delay means for said trip means comprising a time delay mechanism, and a timer lever,'said timer lever and said'trip means having a common biasing means to maintain'said timer lever and said trip means in a first position, said timer-lever eflective'to delay the movement of said trip means when said timer. lever is in said first position; means operatively connected and controlled by said circuit breaker to'move andmaintain said timer lever in a second position while said contacts are moved from said final engaged position to said disengagedposition and back to said initial engaged position.

5. In a circuit breaker having a pair of cooperating contacts with an initial engaged, a final engaged and a disengaged position, a trip and prop latch to maintain said contacts in said. final engaged position, a time-delayed overcurrent means to unlatch said trip latch on the occurrence of an overcurrentcondition to thereby result in said circuit breaker being moved to said disengaged position,.said'overcurrent time delay means comprised of an overcurrent coil, an armature, controlled thereby,

13 a timer mechanism, and a timer arm; said timer arm controlled by said timer mechanism to delay the movement of said armature when said overcurrent coil is energized by an overcurrent, means operated by said circuit breaker and operatively connected to said timer arm to render said arm ineffective to delay the operation of said armature when said prop latch is unlatched,

said prop latch being unlatched When said circuit breaker is in said initial engaged position.

6. In a circuit interrupter having trip means and cooperating contacts with an initial engaged, a final engaged and a disengaged position, time delay means for said trip means comprising a time delay mechanism, and a timer lever, said timer lever and said trip means having means to maintain said timer lever and said trip means in a first position, said timer lever effective to delay the movement 'of said trip means when said timer References Cited in the tile of this patent UNITED STATES PATENTS 839,079 Scott Dec. 18, 1906 2,154,703 Sandin Apr. 18, 1939 2,356,050 Grissinger et a1. Aug. 15, 1944 FOREIGN PATENTS 292,972 Germany July 7, 1916

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