US1823738A - Circuit closing mechanism - Google Patents

Description

Sept. l5, 1931.

J. D. HILLIARD 1,823,738

CIRGUI'T .CLOSING MECHANISM Filed July l. 1929 Jao j fla a /6Q /6 zo -fqld /4 n//a /a /2 ,f /9

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3 K v l Inventor' John D. HLLLLclrd, bg MTM His tIorne/g.

Patented Sept. 15, 1931 UNITED STATES PATENT oFFlcE JOHN D. HILLIARD, OF SCHENECTADY, NEW YORK, ASSGNOR T GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK y CIRCUIT CLOSING MECHANISM Application led July 1,

ence of short circuit or abnormally large currents in the circuit to be controlled is often rendered difficult, due to electromagnetic and other forces tending to force the switch contacts apart, which forces maybe of such magnitude that the contacts are repelled with resultant arcing, or burning, of the contacts. The motive means for ei'ecting closure of the switch contacts, if connected to the switch operating mechanism in the usual manner, must therefore have a much higher power rating than would be required for normal operation, if provision is to be made for closing the switch contacts under eXtreme operating conditions.

A principal object of my invention is to provide circuit closing mechanism of an improved t-ype, wherein energy stored by motive means of comparatively low power rating is utilized to eli'ect positive closing of a switch,

notwithstanding large repellent forces tending to separate the switch contacts.

A further object of my invention is to provide a switch actuator capable of eiiecting a positive closing operation at a speed characteristic of the actuator design.

A further object is to reduce the power rating of the motive'means required for effecting positive closure of the switch contacts under all operating conditions of the circuit to be controlled.

For a better understanding of my invention reference is had to the accompanying drawing which in the single figure illustrates partly diagrammatically a switch operating mechanism.

Although my invention is particularly adaptable to oil circuit breakers, it is equally applicable to large switches of any type requiring large forces to effect operation thereof. Accordingly, details ofthe switch mechanism itself are believed to be unessential for a complete understanding of my invention.

Referring to the drawing, switch operating member 1 is suitably guided for reciprocal movement with respect to a panel support 2,

mounted on frame 3. The operating member 1 is .provided with a locking member 4, which is adapted to co-act with the locking toggles 5 and 6 for restraining the switch operating member in either of its extreme positions. In the position shown, toggle 6 is extended by its energizing relay 6a into restraining engagement with a shoulder of member 4, to hold the operating member in its open circuit position.

The actuating means for the switch operating member comprises a comparatively massive rotatable member 7, as a fly wheel mounted upon a shaft 7a and coupled to driving means, as an electric motor 8. The flywheel 7, through suitable speed reduction means, as the pinion 9, and gear 10, aqtuates cam 11, which is xedly mounted on a counter shaft 10a. Accordingly, it will be seen that cam 11 is continuously rotating during energization of the motor 8, and rotation of the iywheel 7.

For the purpose of operating the switch member 1, independently of the energizing operation of the motive means 8, a disenga gable connection comprising` the cam 11 and a movable thrust-transmitting member 12 is provided to be controlled in a manner hereinafter described. The thrust transmitting member is connected as at the pivotal mounting 13 to the lower end 1a., of the switch operating member. Means for controlling the position ci? member 12 with respect to cam 11, and fornormally biasing it out of engagement therewith, comprises a bell crank, or the like, 14, pivotally mounted at 15 to the frame structure 8, and biased in a clockwise direction by a tension spring 16 secured at its fixed end 16a to frame 3. A sliding operating connection between members 12 and 14 comprises a lug-17 secured to the free end of member 12 and having an enlarged portion 18 extending Within and restrained by the comparatively narrow slot 19 to reciprocatewith respect to a channel-like arm 14a of the bellcrank 14. Accordingly, rotation Y 'of the bell crank is effective to rotate the thrust-transmitting member 12 in the same direction therewith. Connected to theopposite arm of the bell crank 14, as by a pin and 50 gizes relay 6a to bridge contacts 31 and 32,

lill! slot connection 20, is an electromagnetically actuated element 21, comprising the movable core ot an electromagnet 22. Energization of the electromagnet, as hereinafter described, eects downward movement of the core 21, with resulting counter-clockwise vrotation ofl the bell crank 14 against its spring tensioning means to move the thrust transmitting member 12 into the path of movement of cam 11. A control or synchronizing switch 23, movable to alternately connect with contacts 2d and is electrically connected by conductor 26 to one terminal of a source oi' power 27, 28, the other terminal of the source being connected to relay 6a, motor 8, and the electromagnet 22. rlhe tripping relay 50, whichv may comprise the usual overload tripping means, is normally ydeenengized during the open circuit position of the operating member 1, the toggle 5 being held in' its collapsed or releasing position by the member 4 so that the contacts 29 and 30 are bridged. Accordingly, when switch 23 is in en agement with Contact v25, relay 6a is energlzed to bridge contacts 31 and 32 and complete the circuit through the electromagnet 22, effecting energization thereof. Concurrent with energization of relay 6a, and prior to energization of the electromagnet 22, the locking toggle', is caused to collapse to permit movement ot, the operating member 1 to its circuit closing position.

The operation of the system is as follows With the elements of the system in the positions illustrated in the drawing, the control switch 23, which may be remotely posi# tioned, as in the operators room, is moved to engage contact 24, whereupon motor 8 is connected across the source of power 27-28 and brought up to` speed. The iiywhe-el'?, being connected to themotor, isrotated thereby, as is cam 11, through the speed reducing means 9-10. When y-wheel7 has/ been brought upto the desired speed, thel motor 8 is deenergized, and the camming connection between the fly-wheel A7, and switch o erating memberl is established by moving t e control, switch 23 out of engagement with contact '24, and into engagement vwith contact'25. This operation Ifirst ener-l and to break the locking toggle 6, following which the ,'electromagnet 22 is energized through the connectionsso established, and through' the relay contacts 29--30, from the source of power 27-28. Upon energization of the electromagnet 22 its movable core 21v is` attracted downwardly lto move the thrust-transmitting member 12 through its bell crank operator into the path of movement of the rotatin cam 11, asillustrated by its dotted line position. The thrust-transmitting member when it is first actuated by.

electromagnet 22 may be moved against the side edge of cam 11 and so for the vmoment nsaavee kept out ot the path of the cam. However, when the cam has rotated to the position illustrated in the drawing the thrusttransmitting member is free to slip into the dot-ted line position and so is in position to be acted upon by the cam 11.`

As the operating tace or' cam 11,l which may be designed in accordance with the desired speed of closing of the switch operating member, engages the lower end of the thrust transmitting member, the kinetic energy of rotation of the 'fly-wheel 7 is utilized to transmit a comparatively large torce through the aforesaid camming connection to the switch operating member 1; Since the actual circuit closing opera-tion is etected by means of the energy stored in the y-wheel, it is apparent that motor 8 may be of comparatively low power rating, and, in fact, need be of no greater capacity than is required for overcoming the stationary bearing friction of the moving parts Gincluding shaft 7a and its counter shaft 10a. In the event that an appreciable time for closing the circuit is permissible, the fly-wheel 7 may be very massive as compared with the rotating motor structure, and so may be capable of storing a very large amount of energy for closing the switch.

llt is obviously apparent that the mechanical advantage obtained between thev iiywheel 7 and the switch operating member 1 may var to meet the requirements of the particu ar installation; and that the design of cam 11 maybe such that the closing speedv of operating member 1 is substantially uniform or'made to vary in any suitable manner, as by harmonic motion, or

.- the like.`

l When the switch operating member 1 has been moved upwardly to .its closed circuit position, the locking ltoggle 5 is extended y Iunder the influence` Yof gravity or suitable biasing means into its locking position in the lower locking notch in the member 4 so that the circuit breaker is locked in its closed circuit position. Coincident with the locking operation, the circuitv of the electromagnet 22 is broken at thecontacts-29-3O by reason of the extension of the locking toggle 5. The vconsequent deenergization of the electromagnet 22` causes the thrust-transmitting member 12 .to be returned by its spring .16 to the inoperative position illustrated so thtt it is not influenced by the rotating cam 1.

With the` circuit breaker locked in its closed'positiom'the control or synchronizing switch 23 is returned to the lmeutral position illustrated. Accordingly, subsequent actuation of the tripping relay 5a in response to. predetermined-overload for example, is ei'ective to break the locking toggle 5, releasing the switchmemberl -and permitting cir- .cult opening' movement tothe/position il-/l/ lustrated. During this operation the locking toggle 5 rides along the side of the member 4 to maintain the connection between the contacts 29 and 30, independently of the state of energization of the relay 5a, and the locking toggle 6 is extended b gravity or suitable biasing means into loc ing engagement'with-the upper locking notch in the member 4 so that the mechanism is in readiness to repeat the previously described cycle of operation.

It shall be further understood that my invention is applicable broadly toY any operating system wherein a large positive force is required to move an operating member into a desired position.

What I claim as new and desire to secure by `Letters Patent of the United Statesfis 1. A circuit closing system com rising a switch operating member, a rotata le -member, means effecting rotation of said member, a disengageable connection between said rotatable member and said switch operating member, and means controlling said connection in accordance with a circuit controlling ,position of said operating member, the kinetic energy of said rotatable member being effective to actuate said switch operating member through said connection.

2. A circuit closing (system comprising a switch operating member, a (rotatable meniber having considerable mass, driving means effecting rotation of said member, a disengageable connection between said rotatable member and said switch operating member, and electromagneticl means controlling'said connection in accordance with a,y circuit controlling positiowof said operating member, the kinetic energy of rotation of said rotatable member being effective to actiiate said switch operating member through said con-Y nection notwithstanding concurrent deenergization of the aforesaid driving means.

a 3. A circuit closing system comprising a switch operating member, a rotatable member having considerable mass, means for bringing said rotatable member up to a predetermined speed, a disengageable camming connection between said rotatable member and said switch operating member, and means for establishing said connection when said predetermined speed has been attained whereby the energy stored in said rotatable member is effective to cause actuation of said switch operating member.

4. A circuit closing system comprising a switch operating mcmberf'a flywheel, means for bringing said flywheel up to' a predetermined speed, a clamming member actuated by said flywheel, and means movable into the path of said camming member for transmittin energy from said rotating flywheel to sai switch operating member to effect closing movement thereof.

5. The combination with a switch operating member, of a flywheel, motive means for bringing said flywheel up to a predetermined speed, a camming member driven by said fly-v combination, a switch operating member, a

rotatable member, motive means for bringing said rotatable member up to a predetermined speed, a disengageable connection between said rotatable member and said switch operating member for transmitting kinetic energy of rotation from the rotatable member to the switch operating member to effect closing movement thereof, means for establishing said connection substantially coincident with deenergization of said motive means, and means for rendering said connection inoperative in accordance with a circuit controlling position of said switch operating member.'

7. In a switch operating system, in combination, anoperating member, a comparatively massive driven member, driving means for imparting motion of'rotation to said driven member, a disengageablel camming connection adapted to be established between said driven and operating members for transmitting motion to said operating member, and means for establishing said connection whereby the kinetic energy of rotation of said driven member is effective to actuate said operating member.

8. In a switchv operating system, in combination, an operating member, a comparatively massive driven member, driving means for imparting motion of rotation to said driven member, disengageable thrust-transmitting means interposed between said driven and operating members, means for rendering operative said thrust-transmitting means whereby the kinetic energy of rotation ofsaid driven member is effective to actiiate said operating member, and means for rendering inoperative said thrust-transmitting means in response to movement of said operating inember to closed circuit position.

9. A circuit closing system comprising in combination, a switch operating member, a comparatively massive rotatable member, motive means for bringing said rotatable member up to. a predetermined speed, a cam driven by said rotatable member, a member movable into the path of motion oft' said cam for transmitting motion'from said rotatable member to said switch operating member, and electromagnetic means controlling the engagement of said movable member and cani, whereby the kinetic energy of rotation of said rotatable member may be utilized to eliect closing movementv of said switch op-.' eratin'g member.

10. A.. circuit closing system comprising, in combination, a switch operating member, a comparatively massive rotatable member, a cam driven by said rotatable member, motive means for bringingsaid rotatable member up to a predetermined speed, a thrust-transmitting member normally out of engagement with -said cam, and means for moving said thrust-transmitting member into engagement with said cam when said predetermined speed has been attained, wherebythe kinetic energy of rotation of said rotatable member is effective to cause movement of said switch operating member to its closed position at a speed dependent upon the design of said cam.

11. A circuit closing -system comprising in combination, a switch operating member, a comparatively massive rotatable member, a cam driven by said rotatable member, a thrust-transmitting member interposed between said cam and switch member for transmitting motion from saidrotatable member to said switch operating member, said thrusttransmitting member normally biased out of engagement with -said cam electromot-ive means for bringing said rotatable member up to a predetermined speed, electromagnetic means t'or biasing said thrust-transmitting member into engagement with said cam, and energizing said electromagnetic means to effeet the aforesaid camming engagement whereby the kinetic energy of rotation of said rotatable member is utilized to effect closing movement of said switch operating member.

12. A circuit closing system comprising'in combination, a switch operating member, relaycontrolled locking means for restraining said operating member in its open position, a

' rotatable member, a cam driven'by said rotatable member, a thrust-transmitting member interposed between said cam and switch operating member for transmitting motion to said switch member, said thrust-transmitting member normally biased out of engagement with-said cam, an electric motor for bringing said rotatable member. up to a predetermined speed, an electromagnet for biasing said thrust-transmitting member into a camengaging position, and circuit controlling meansfor sequentially deenergizing said .electric motor, releasing saidlockingv means and energizing said electromagnet to bias said thrust-transmitting member into said camenga'ging position, whereby the kinetic energy of rotation of said rotatable member is utilized to cause closing movement of said switch operating member.

13.- In a circuit closing system, the combination with a switch operating member, of means for effecting substantially uniform and positive closing movement of said member comprising driving means, a flywheel adaptrsaares ed to be rotated at a predetermined speed by said driving means, and electromagnetic means for causing transmission of power from said flywheel to said switch operating member when said fly-wheel is brought up to operating` speed, the kinetic energy of rotation of said flywheel being effective to cause closing movement of the switch operating member independently of said driving means notwithstanding repellent forces tending to oppose closing movement of said member.

14. In circuit controlling apparatus, operatin means comprising 'a switch operating mem er, a flywheel arranged to transmit power to said member to effect closing movement thereof, means for driving said flywheel at a predetermined speed, and electromag-l netic means for causing transmission of power from said flywheel to said switch operating member when said flywheel is brought up to operating speed, the kinetic energy of rotation of said flywheel being effective to cause substantially uniform and positive closing movement of said member notwithstanding repellent forces tending to oppose closing movement thereof.

ln witness whereof, Ifhave hereunto set 'my hand this 26th day of June 19:29. f

JHN HILLIARD.

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