US2069082A - Automatic reclosing electric circuit interrupter - Google Patents

Description

Jan. 26, 1937. L. s. WALLE 2,069,082

AUTOMATIC RECLOSING ELECTRIC CIRCUIT INTERRUPTER Filed Dec. 24, 1954 2 Shets-Sheet 1 Invent o1:

Ludwig S. A/alle.

by] a 49W L. S. WALLE Jan. 26, 1937.

AUTOMATIC RECLOS ING ELECTRIC CIRCUIT INT ERRUPTER Filed Dec. 24, 1954 2 Sheets-Sheet 2 Inveht-ow;

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Patented Jan. 26, 1937 PATENT OFFICE AUTOMATIC RECLOSING amo'mrc cm- CUIT INTERRUPTER Ludwig S. Walle, Lansdowne, Pa., assignonto General Electric Company, a corporation of New York Application December 24, 1934, Serial No. 758,902

8 Claims.

My invention relates to electric circuit interrupters of the automatic reclosing type, more particularly to a circuit interrupter oi the aforesaid type wherein the reclosing operation is delayed for a predetermined time and the interrupter is locked in open circuit position after a predetermined number of consecutive reclosures in the event that the fault still obtains, and has for its principal object the provision of an improved automatic reclosing circuit interrupter which is simple, compact and economical in construction and efficient in operation.

My invention will be more fully set forth in the following description referring to the accompanying drawings, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawings, Fig. 1 is a lateral view, partly in section, of an automatic reclosing circuit interrupter embodying my invention, and Fig. 2 is a similar view of a preferred commercial form which my invention may assume.

In certain power areas of large electrical power transmission systems, such as for example suburban and rural areas, the power is transmitted by a single phase line which is quite generally protected by fuses. These lines which may operate under a tension of the order of 7500 volts, for example, often extend through wooded areas where short circuit possibilities, due to falling limbs, etc., are comparatively high. In case of a short circuit under such conditions the line may be cut out of operation by the fuse for an appreciable length of time depending on replacement of the fuse by the maintenance crew.

As is well known, the percentage of temporary or momentary short circuits in modern electric power transmission systems is comparatively high, so that in a large majority of cases immediate reclosure of the circuit restores service. However, on comparatively low power single phase extensions reclosing circuit breaker systems have not been used due to the prohibitive cost of such installations.

In accordance with a preferred form of my invention a simple and compact automatic reclosing circuit breaker is incorporated in a single unit which may be suitably mounted, such as by suspension from a wooden cross arm of the power line pole, and out directly into the line. The circuit breaker is arranged automatically to reclose for a predetermined number of consecutive operations, after which the breaker is locked in open circuit position. A suitable time delay may be introduced in each reclosing operation. After the breaker is locked out, it may be manually reset such as by the use of the conventional disconnecting switch pole, such means being also efiective manually to open the breaker and lock the same in open circuit position.

Referring more particularly to Fig. 1, there is illustrated an automatic reclosing circuit interrupter comprising a casing, formed in the present instance by an insulating cylinder I closed at the opposite ends thereof by terminal caps 2 and 3, respectively. Normally the casing is vertically positioned, the lower portion thereof to the level at 4 containing a suitable arc extinguishing liquid, as oil, in which circuit interrupting means, such as relatively movable contacts 5 and 6, operate. The contact 5 is fixed, forming a part of of the circuit breaker terminals l I, the other solenoid terminal being suitably connected as by a flexible lead I! to the movable contact 6. It will, therefore, be noted that the coil of solenoid 9 is connected in series with the breaker terminals and the contacts 5 and 6, i. e., in series with the circuit to be interrupted.

The solenoid 8 is suitably mounted within the casing I, such as by an insulating spool i3 which is positioned between insulating cylinders I4 and I4. The cylinder H comprises the lining of the circuit interrupting chamber l5 and the cylinder It serves also to anchor the opposite ends of a transverse bar Hi. The upper part of the casing is provided with another insulating cylinder I4" between which and the cylinder I4 is I mounted a partition i.

The solenoid armature 8 is provided with a non-magnetic tubular extension I! of brass or the like which is slotted at IT so as to be guided for vertical movement by the transverse bar IS. The movable contact 6 is normally biased towards closed circuit position, such as by a compression spring I8 mounted within the armature and its extension and bearing against the fixed transverse bar it and movable contact, respectively.

In the arrangement so far described it will be apparent that upon overload or excess current, the armature 8 of the solenoid will be drawn into the coil effecting separation of the contacts 5 and 6 in chamber l6 and causing interruption of the circuit within the arc extinguishing liquid. To this end the tubular movable contact 6, armature 8 and extension I! form a continuous exhaust passage from the chamber l5, thereby relieving excessive arc pressures and aiding circuit interruption. Immediately upon interruption of the circuit the solenoid is deenergized so that under the bias of the spring i8 the contact 6 tends to return to closed circuit position.

For the purpose of retarding reclosure of contact 6 and for locking said contact in open circuit position after a predetermined number of consecutive operations, there is provided in operative relation with the contact 6 lockout and escapement devices within an upper chamber id. The movable contact is operatively connected to said devices through a ratchet including a ratch et member 20 carried by and pivotally connected, as at 2|, to the armature extension II and having ratchet teeth, as at 22, for engaging a coacting ratchet wheel 23 carried by shaft 24 which is suitably mounted in the breaker casing. Resilient means, such as a spring 25 mounted on partition I, normally biases the ratchet member 20 into engagement with the ratchet wheel 23, the arrangement being such that the ratchet teeth engage and cause rotation of shaft 24 only on'the downward or reclosing stroke. In

the closed circuit position shown, the ratchet teeth are entirely out of engagement.

The lockout device comprises a suitably biased, such as weighted, member 26 guided for reciprocal longitudinal movement and having a gear rack 21 arranged to mesh with a gear 28 also mounted on the shaft 24. The lockout member 26 is provided at its upper end with an offset extension 29 for coacting with an adjustable stop member 36 which limits the upward travel of the lockout member.

Since the lookout member 26 is geared to the shaft 24, each reclosure of the breaker in rotating the shaft 24 in clockwise direction raises the lookout member 26 towards its upper limit. When in such limiting position theshaft 24 is restrained with respect to further clockwise rotation and the movable contact through the above described ratchet is held in the open circuit position against the bias of the reclosing spring is. Disengagement of the ratchet, as by pivotal movement of the ratchet member 20 against the bias of its spring 26, releases the movable contact so that reclosure is effected; also the lookout member 26 returns to its lower position while rotating the shaft 24 counterclockwise.

The e'scapement device for delaying the reclosing operation generally indicated at 3| is of an oscillating type, for example, and is connected through a gear train 32-33 to the shaft 24. A large diameter gearwheel 33 is secured to the shaft 24 and the cooperating pinion gear 22 is secured to a. shaft 34 of the escapement device. The shaft 34 has likewise mounted thereon an escapement wheel 36 coacting with the pivoted oscillating member 36. It will, therefore, be apparent that the escapement device is operatively connected at all times through the shaft 24 to the lockout device and to the movable contact during the reclosing operation.

The operation of the automatic reclosing circuit interrupter is as follows: Upon the occurrence of an overload or short circuit the solenoid 6 eflfects upward movement of the movable contact structure including ratchet member 20.

thereby interrupting the circuit within the chamber l5. During upward movement of the ratchet memmr 20 the ratchet teeth do not operatively engage and the shaft 24 is not actuated. As the movable contact structure descends under the bias of spring iii the ratchet teeth engage and mesh, thereby rotating the shaft 24 in clockwise direction. The escapement device 3|, however, retards the rotation of shaft 24 with the result that the movable contact returns slowly towards closed circuit position. It will be apparent that the delay inreclosure may be chosen to meet the particular operating requirements. Near the end of the reclosing operation the ratchet teeth disengage, thereby insuring a positive reclosing force.

place before the lookout extension 29 engages the adjustable stop member 30.

When the lookout member 26 is advanced to its lockout position, the breaker on its next opening operation is locked in open circuit position as above described. The breaker may be reclosed and reset such as by suitable manually operable means (not shown) mounted exteriorly of the breaker casing for moving the ratchet member 20 away from the ratchet wheel 23.

In the event that there are but one or two reclosures and the line clears before the breaker is locked out, the lookout member 26 returns by gravity to its reset position, subject of course to the retarding effect of the escapement. Accordingly, the breaker is locked out only upon the occurrence of a predetermined number of consecutive operations.

In a preferred form of my invention shown by Fig. 2, the above described arrangement is fundamentally the same. The breaker casing in the present instance is a steel tank having an insulating lining 40. The relatively movable contacts 6 and 6 are immersed in an arc-extinguishing and insulating liquid as oil, the level of which is indicated at 4. The movable contact 6 is operated by the solenoid armature 4| which is slidably mounted on the non-magnetic contact rod 42. Energization of the operating solenoid 9 in response to predetermined overload causes the armature 4| to move rapidly upwards into the coil and to engage a shoulder formed at 43 on the contact rod for effecting quick opening movement of the contact 6. The lost motion connection between the armature 4| and the contact 6 not only results in high speed separation of the contacts but lowering of the minimum pick-up current. The energy stored in the moving armature likewise serves to elevate the ratchet into proper operative engagement with the ratchet wheel.

The lockout and escapement devices are reoil the pivoted ratchet member and a contact controlling member 46. The frame 44 comprises a pair of spaced plates between which, at 41, the ratchet member 45 is pivotally supported. The frame 44 is likewise provided with an offset extension 48 on which the member 46 is pivotally mounted at 49. A compression spring 50 seated between members 45 and 46 tends to bias the ratchet member towards the coacting ratchet wheel 5|.

The controlling member 46 at its upper end is pivotally connected at 52 to a crank 53 having an arm 54 mounted exteriorly of the breaker casing i. The crank 53 which is pivotally mounted at 55 on the casing is normally biased, as by a spring 56, in clockwise direction so as to bias the member 46 and consequently the movable contact 6 towards closed circuit position.

The exterior crank arm 54 is hook-shaped as illustrated so as to facilitate engagement with a conventional pole switch hook 51. In the position shown it will be apparent that an operator can engage the crank arm 54 with the switch hook so as to push the crank counter-clockwise, thereby causing upward or circuit opening movement of the contact 6 against the bias of the reclosing spring 56.

For the purpose of manually locking the breaker in open circuit position a latching member 53 pivotally mounted at 59 exteriorly of the casing is provided with an inwardly extending lateral flange 60 arranged to coact with the crank arm 54'. The latch member 58 is provided with oppositely disposed hooked portions 5! and 62 for coaction with the switch hook 51. When the crank 54 is raised by the switch hook, the switch hook likewise engages the latch portion 6!,

thereby rotating in clockwise direction the latch so as to cause the ofiset flange 60 to pass underheath the edge 54' of the crank. The breaker is accordingly held in open circuit position by the latch 5t and may be released by pushing the opposite latch extension 62 with the switch hook so as to rotate the latch in a counter-clockwise direction. Accordingly, the control device like wise serves as a visual indicator of the circuit controlling position oi the breaker.

The escapement ratchet wheel 5i, as in the previous instance, is mounted on a shaft which is suitably biased as by a spring 54 in counter-clockwise direction. Spring 54 is anchored at one end by fixed screw 64. Likewise mounted on the shaft 65 is a lookout member 85 which is in the form of a large gear wheel arranged to mesh with the escapement pinion 6E. The escapernent 87-88 is of the oscillating type.

For the purpose of limiting the angular movement of the lockout member 65 a peg or lug 59 is secured thereto for engagement with adiustable stop screw iii secured with respect to the switch casing. As illustrated, the fixed stop member may be positioned so as to provide for a varying number of reclosures. In the reset position illustrated, the gear wheel 65 is re-- strained with respect to counter-clockwise rotation by a stop member (not shown).

The operation of the device is believed to be apparent from the above description. when the solenoid 9 attracts the armature 45, causing upward movement of the contact rod and frame it, the ratchet member 45 is elevated above the coacting ratchet wheel so that reclcsure is retarded by the escapement coincident with clock wise rotation of the lookout member. If the iault still obtains, the next reclosure advances the lockout member until after a predetermined number of consecutive reclosures the member 65 is restrained with respect to clockwise rotation and. the breaker locked in open circuit position.. In this position the crank arm 54 is elevated so as to indicate that the breaker is open and locked out. Manual resetting is effected simply by pushing upwardly on the crank 54 with the switch hook so as to disengage the ratchet means. The lockout member 65 thereupon returns to its reset position under the counter-clockwise bias of the spring 64. Release of the crank 54 is followed by closing of the breaker under bias of the closing spring 56.

The complete circuit breaker structure is adapted for mounting as a unit on the wooden cross arm of the conventional low voltage transmission pole. The steel tank I is provided with cover structure ll suitably secured, as by screw studs 12, to the breaker tank. The cover structure is provided with downwardly extending lateral extensions F3 in which are mounted the leadin insulating bushings 14 for the line conductor 55. The insulators are suitably mounted and sealed, as at 56, so as to seal the breaker against moisture, etc. secured, as at iii, to the cover structure for facilitating inspection. A pair of supporting lugs 19 are secured to the cover structure so that the breaker as a unit may be suspended irom or slung beneath the pole cross arm.

The breaker contacts and mechanism are likewise mounted as a unit within the tank in an insulating tube 85 which is supported at the bottom of the casing. The tube is rigidly maintained in operative position such as by a split ring 80' which is secured at 80" to the cover structure H and abuts a shoulder of the tube This arrangement permits lowering of the tank i with respect to the supporting cover structure by simply loosening the bolts 12, the tube 80 remaining in position. The interrupting unit supported within the insulating tube 80 may, therefore, be readily inspected.

The fixed contact 5 is supported by an insulat-= ing partition 8| positioned between insulating spacing cylinders 82 and 83. The partition 8i forms with the lower wall of the casing a connection chamber in which the contact 5 is connected, such as at 84, with one of the line concluctors. The other line conductor is connected at 85 to the upper terminal of the solenoid, the lower terminal of which is connected by flexible conductor 86 to the movable contact 5.

The interruption chamber M is provided with an exhaust port at 88 opening into the space 88 between the insulating cylinder 80 and the circult breaker tank. Upon separation of the con-- tacts the are formed therebetween generates pressure in the oil so as to cause rapid expulsion of oil through the exhaust port tending to interrupt arcing.

The solenoid 9 is mounted Within the insulating cylinder 88 between pole plates 90 and 96, the plate iii supporting a pair of mounting plates 92 between which the escapement deviceand shaft 63 of the ratchet means are mounted.

It should be understood that my invention is not limited to the range of voltage and power rating indicated and to specific details of construction and arrangement thereof herein illustrated, and that changes and modifications may occurto one skilled in the art without departing from the spirit ofmy invention.

A cover plate 11 is sealed and What I claim as new and desire to secure by Letters Patent of the United States, is,--

1. An electric circuit interrupter of the reclosing type comprising circuit interrupting means, means for reclosing said interrupting means after a circuit opening operation, a lockout member, and means including a ratchet and gear train operatively connected to said interrupting means arranged to advance said member during each reclosing operation, said member being moved by said ratchet to a restrained positicn in response to a predetermined number of consecutive reclosures so that on the next opening operation said interrupting means is held in open circuit position.

2. An electric circuit interrupter of the reclosing type comprising circuit interrupting means, means for reolosing said interrupting means after a circuit opening operation, a lockout member limited to a predetermined range of movement, means including a ratchet member operatively connected to said interrupting means arranged detachably to engage said lockout member in accordance with each reclosing operation, means resiliently biasing said ratchet member into operative engagement, said ratchet member moving said lockout member to a restrained position in response to a predetermined number of consecutive reclosures for holding said interrupting means in open circuit position, means for disengaging said ratchet member and lockout member for effecting reclosing and resetting operations, and an escapement device operatively connected to said lockout member for delaying reclosure of said interrupting means and resetting of said lockout member.

3. An electric circuit interrupter of the re-* closing type comprising relatively movable contact structure, means for reclosing said contact structure after a circuit opening operation, a lockout member limited to a predetermined range of movement, means including a ratchet member movable with and pivotally connected to said contact structure, said ratchet member resilient ly biased into operative engagement with said lockout member and arranged to actuate said lockout member by progressive stages to a restrained position in response to a predetermined number of consecutive reclosures for holding said contact structure in open circuit position, means disengaging said ratchet member in the lookout position for effecting reclosure of said contact structure and resetting of said lockout structure" and said lockout member arranged torotate said member towards lockout position in accordance with each reclosing operation, said lockout member being rotated to a restrained position in response to a predetermined number of consecutive reclosures for holding said ratchet and movable contact structure in open circuit positiomand an escapement device operatively connected through a gear train to said lockout member so as to delay reclosure of said movable contact structure when said structure is connected to said lockout member through said ratchet.

5. An electric circuit interrupter of the reclosing type comprising a casing, coacting fixed and movable contacts arranged to separate within an insulating liquid in the lower part of said casing, a solenoid having an operating coil in series in the circuit to be interrupted for operating said movable contact, said solenoid being mounted within said casing and in vertical alinement with said movable contact, escapement and lockout devices operatively connected to said movable contact and mounted within said casing above said solenoid comprising a rotatable lockout member limited to a predetermined angular movement, a ratchet wheel connected thereto, a ratchet member pivotally connected to said movable contact for engaging said ratchet wheel arranged to rotate said wheel and lockout member in accordance with each reclosing operation,

said lockout member being moved to a restrained position in response to a predetermined number of consecutive reclosures for holding said movable contact in open circuit position, an escapement operatively connected through a gear train to said rotatable lockout member, a member mounted on and operable exteriorly of said casing connected to said ratchet member for disengaging the same and said ratchet wheel, and means independent of said lockout means for holding said movable contact in open circuit position.

6. An electric circuit interrupter of the reclosing type comprising relatively movable contact structure, means for efiecting circuit opening movement of said contact structure, means biasing said contact structure towards closed circuit position, a lookout member limited to a predelermined range of movement, means biasing said member towards one of its limiting positions, a ratchet arranged operatively to interconnect said lockout member and contact structure so that said member is progressively moved to its other limiting position by said contact structure biasing means in opposition to said second-named biasing means in accordance with a predetermined number of consecutive reclosures of said contact structure, said lockout member through said ratchet thereupon holding said contact structure in open circuit position, means for disengaging said ratchet whereby contact reclosure is effected, and an escapement device operatively connected to said lockout member'for delaying contact reclosure and resetting movement of said lockout member.

'7. In an automatic reclosing arrangement for electric circuit interrupters including a circuit interrupter and closing means therefor, a. ratchet movablein accordance with an operation of said interrupter, the reclosing operation being dependent on predetermined movement of said ratchet, av lock-out member arranged to be advanced by said ratchet, means for applying a bias in opposition to said movement, and an escapement operatively connected to said ratchet for retarding movement thereof, said lock-out member being advanced so as positively to block operation of said closing means after a predetermined number of consecutive reclosures.

8. In an automatic reclosing arrangement for electric circuit interrupters including a circuit interrupter and closing means therefor, a ratchet including a member for controlling closing of said interrupter movable in accordance with an operation of said interrupter, a lock-out member nected to said ratchet for retarding movement thereof in either direction so as to retard both resetting of said lock-out member and reclosure of said interrupter, said lock-out member being advanced in successive stages so as positively to block operation of said ratchet and closing of said interrupter after a predetermined number 5 of consecutive reclosures.

LUDWIG S. WALIE.

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