US2001898A - Circuit interrupter - Google Patents

Description

May 21, 1935- w. M. AUSTIN 2,001,898

CIRCUIT INTERRUPTER Filed Jan. 8, 1919 l WITNESSESI WJ/er M' Ausf/n Patented May 2l, 1935 PATENT OFFICE cmcurr INTERRUPTER Walter M. Austin, Swissvale, Pa., assigner to Westinghouse Electric & Manufacturing Company a corporation of Pennsylvania Application January 8, 1919, Serial No. 270,110 13 claims. (ci. zoo-109) My invention relates to electrical protective devices and particularly to latch mechanisms for circuit interrupters. r

The object of my invention is to provide a device ofthe above indicatedv character that shall be simple and durable in construction and eiective in operation and that may not be actuated to undesirably open the interrupter when subjected to heavy jarring.y

In practicing my invention, I provide a latch mechanism comprising main and auxiliary interdependent movable latch members, the auxiliary member being biased toward its latching position in engagement with the main member that engages the movable arm ora circuit interrupter and is biased towards its releasing position. The latch members are so formed and related as to requirea relatively slight actuating force and are so positively positioned as to be protected against 20 accidental release by jarring.

Figure 1 of the accompanying drawing is a view, partially in side elevation and partially in section, of a circuit interrupter embodying my invention, and Fig. 2 is a detail View, on an enlarged scale, of portions of the device shown in Fig. 1. f

A circuit interrupter I is -mounted upon a panel 2 and comprises two main stationary contact members 3 and 4, auxiliary stationary contact members 5 and 6 and brackets 1, only one of which is shown, upon which are pivotally mounted an arm 8 carrying a. movable contact member 9 vfor engaging the member 6 and a second movable arm I8 comprising a resilientlymounted member II for engaging the member 5, a laminated bridging member I2 that is pivotally mounted thereon, and a cam member I3. The lever arm I0, pivotally connected to the brackets 1 by a pin 2|, is connected to the member I2 by a pin I4 and to the arm 8 by a spring-and-rod connection I5. An operating lever arm I6 has a roller member I1 at one end thereof for engaging the cam memberr I3, and two projections vI8 and I9 that extend substantially at right angles therefrom. Springs 28 connect the projections I8tothearm I0.

The pin 2| and a pin 22 extend between the brackets 1 and support a pair of stationary plates 23, only one of rwhich is shown, to which pins 24 and 25 are held. A latch member 26, pivoted on the pin 25, has a, relatively short arm 21, in which oppositely facing shoulders 28 and 29 are formed for engagement with an adjustable latchengaging member 30 on the projection I9 anda y 55 relatively long arm 3| for engagement with a detent 32 on a trigger 33 pivoted on the rod 22. The member 30 comprises a threaded bolt 34 positionedin a threaded recess in the end of the projection I9 where it is held in adjusted position by a lock nut 35.

A rcurved lug 36, on the trigger 33, bearing against the pink 24, thereby limits the counterclockwise turning movement of the trigger, as viewed inthe drawing, and serves as a support for one end of a spring 31 that is joined, at its 10 other end, to a lug 38 on the latch member 26 and tends to turn the latter in a clockwise direction.

The trigger 33 has a projection 39 that extends to a position adjacent the arm I0 and operates, in co-operation with the latter, to prevent the l5 resetting of the latch member 26 to the position shown when the interrupter is in its open position.

An armature member 40, for co-operation with pole pieces 4I of an electromagnet 42, comprises 20 arms 43, only one of which is shown, pivoted on the pin 22, a projection 44, to which a rod 45 and balance-Weight members 46 are attached, and a bridging portion 41 extending between the arms 43 and which also has a shoulder 48 formed 25 thereon for tripping engagement with a projection 49 on the trigger 33.

A hand-tripping mechanism comprises a handle 50 attached to a lever 5I pivoted on the pin 22. The lever 5I has an arm 52 to engage the 30 trigger 33. A projection 53 on the lever 5I engages one end of a bracket 54 on the panel 2 to limit the movement of the lever 5I'.

A calibrating mechanism comprises a bifurcated depending member 55 that is attached to 35 the pin 22 by arms 56 and carries a calibrated scale plate 51. A screw-threaded rod 58, loosely mounted at its ends in spaced offset portions 58 of the member 55, has a handle 60 at one end and carries a traveling nut 6I having a pointer 40 62 for co-operation with the scale plate 51. A lever 63, loosely pivoted, at its ends, to the bracket 54 and the nut 6I, respectively, pivotally supports a dash pot 64. Numeral 64 indicates a piston between which and a pin 65 in one of the 45 arms 43, a link 66 extends.

When the interrupter is actuated to its closed position, the operating lever arm I6 is turned in a clockwise direction until the member 30 `engages the shoulder 28 of the latch member 26. Fur- 50 ther movement of the arm I6 causes the member 26 to rotate in a counter-clockwise direction about the pin A25 until the detent 32, by reason of the disposition of the spring 31 between the lugs 36 and 38, is snapped into the position, with respect 55 to the arm 3i of the member 26, shown in the drawing.

During the above described movements, the shoulder 29 is interposed in position behind the member 30 to latch the interrupter in its closed position, as shown in the drawing.

To prevent the inadvertent resetting of the latch member 2S to its latching position while the interrupter is in its open position, which resetting, upon the attempted closing of the interrupter, would cause the member 30 to be jammed against the outer end of the arm 2l, with possible consequent damage to the members thus engaged, the projection 38 on the trigger 33 is interposed in the path of movement of the arm i0. The latter, in the open position of the interrupter, bears against the projection 39 and, thereby, the detent 32 is held in position out of the path of movement of the arm 3l. During the operation of closing the interrupter, the projection 3S will be released to permit the trigger to assume its operative position.

By reason of the proportions and relation of the arms 2l and 3l of the latch member 25, the force exerted by the member 30 against the shoulder 29 will be considerably reduced between the arm 3l and the detent 32, thereby permitting the magnet 42 to be smaller than would otherwise be necessary. The reduction of the force between the arm 3| and the detent 32 permits the spring 3l to be of a relatively high-tension value which, taken in conjunction with the relatively small mass of the trigger 33, causes the latter to be highly resistive to heavy vibrations, such as jarring.

The arrangement provides a simple, economical and positive latch mechanism and particularly adapts the interrupter for effective service in positions subject to heavy vibrations, such as aboard war ships.

While I have shown and described a particular form of my invention, changes may be effected therein, without departing from the spirit and scope thereof, as set forth in the appended claims.

I claim as my invention:

1. In a circuit interrupter, the combination with a movable contact-carrying arm and an operating lever therefor, of a latch mechanism comprising an adjustable stop-member disposed on said lever, a pivoted main latch member having arms of diiierent lengths, the shorter of which has a pair of oppositely disposed shoulders thereon for engagement with said stop member, a pivoted auxiliary latch member for engagement with the longer of the said main latch arms and having a projection, said projection extending to a position adjacent said contact-carrying arm to prevent the operation of said auxiliary latch member when the interrupter is in its open position, a spring connecting said latch members, a stop member for said auxiliary latch membery and means for operating said auxiliary latch member.

2. In a circuit interrupter, the combination with a movable contact-carrying arm and an operating lever therefor, of a latch mechanism comprising a pivoted main latch member having arms of different lengths, a pivoted auxiliary latch member for co-operation with said main latch member and having means co-operating with said contact-carrying arm to prevent the operation of said auxiliary latch member when the interrupter is in its open position, resilient means biasing said latch members in opposite directions about the pivots thereof, and means for releasing said latch members.

3. In a circuit interrupter, the combination with a movable member, of a latch mechanism therefor comprising a pair of interdependent movable latch members, a single means for biasing said latch members toward predetermined positions, and means including the movable member rstmentioned for preventing the setting of said latch members in the latched co-operative relation thereof while the interrupter is in its open position.

4. In a circuit interrupter, the combination with a movable member', of a latch mechanism therefor comprising a plurality of co-operating latch members, and means for preventing the movement of one of the latch members to its latching position while the interrupter is in open position independently of current values controlling the circuit interrupter.

5. An electric switch comprising a movable contact member biased to circuit-opening position, main latching means for restraining said contact member in circuit-closing position, auxiliary latching means having a portion adapted to engage and hold said main latching means in latching position, and a resilient connection between said main and auxiliary latching means arranged to bias said auxiliary latching means to latchengaging position and means for holding said auxiliary latching means out of latching engagement with said main latching means when said main latching means is not in latching position.

6. An electric switch comprising a movable contact member biased to circuit-opening position, an operating member adapted to be operated to move said contact member to circuit-closing position, a main latching member for engaging and restraining said operating member to cause the same to hold said contact member in circuitclosing position, an auxiliary latching member of relatively small mass adapted to engage and hold said main latching member in latching position, and a spring interconnecting said main and auxiliary latching members and arranged to bias said auxiliary latching member to latch-engaging position with a large force whereby said auxiliary latching member is substantially shock-proof,

and means including a portion engageable with said auxiliary latching member for holding said auxiliary latching member out of latching engagement with said main latching member when said movable contact member is in circuit-opening position and said main latching member is out of restraining engagement with said operating member.

7. In a circuit interrupter, the combination with a movable member biased to open position, of a latch mechanism therefor comprising a. plurality of cooperating latch members, one of said latch members being engageable with said movable member, and another of said latch members being engageable with the rst said latch member for latching it in engagement with said movable member, and means for preventing the movement of the second of said latch members to its latching position while the interrupter is in its open position with the first said latch member disengaged from said movable member independently of current values controlling the circuit interrupter.

8. In a circuit interrupter, the combination with a movable member biased to open position, of a latch mechanism therefor comprising a plurality of cooperating latch members, one of said latch members being engageable with said movable member, and another of said latch members being engageable with the first said latch member for latching it in engagement with said movable member, a spring connectedbetween said first and second latch members for biasing both of said latch members, and means for preventing the movement of the second of said latch members to its latching position while the interrupter is in its open position with the first said latch member ydisengaged from said movable member independently of current values controlling the circuit interrupter.

9. In a circuit interrupter, a contact movable to open and close the circuit, a member movable upon actuation of said contact, means for biasing said contact and said movable member to move to open-circuit position, a latch member engageable with said movable member, a second latch rmember engageable with the first said latch member for holding it in engagement with said ymovable member, electro-responsive means for causing movement of said second latch member out of engagement with said first latch member and thereby permitting said first latch member to disengage said movable member and allow it and said contact to move to open-circuit position, and means for engaging said second latch member and holding it in disengaged position at least for an interval of time prior to each re-engagement of said first latch member with said movable member.

l0. In a circuit interrupter, a contact movable to open and close the circuit, a member movable upon the actuation of said contact and having a catch portion thereon, means for biasing said contact and said movable member to move to open-circuit position, a latch member for engaging said catch portion on the movable member and holding said movable member against its bias, said catch portion on ,the movable member exerting a force on said latch member capable of moving said latch member to disengaged position, a catch portion on said latch member, a second latch member for engaging said catch portion on the first said latch member and holding the rst said latch member in engagement with said catch portion on the movable member against the force exerted on the first said latch member, electro-responsive means for causing movement of said second latch member out of engagement with said catch portion on the first latch member and thereby permitting said first latch member to disengage said catch portion on the movable member and allow said movable member and said contact to move to open circuit position, and means for holding said second latch member out of latchlng engagement with the catch on said first latch member at least until shortly before said rst latch member is re-engaged with the catch portion on the movable member.

1l. In a circuit interrupter, a contact movable to open and close the circuit, a member movable upon the actuation of said contact and having a catch portion thereon, means for biasing said contact and said movable member to move to opencircuit position, a pivoted latch member for engaging said catch portion on the movable member and holding said movable member against its bias, said catch portion on the movable member exerting aforce on said latch member capable of moving said latch member to disengaged position and the perpendicular distance between the line of action of the force exerted by said catch portion on said latch member and the pivot point of said latch being small, a catch portion on said latch member, a second latch member for engaging said catch portion on the first said latch member and holding the first said latch member in engagement with said catch portion on the movable member against the force exerted on the first said latch member and the perpendicular distance between the line of action of the holding force exerted on said first latch member and the pivot point thereof being large, electro-responsive means for causing movement of said second latch member out of engagement with said catch portion on the first latch member and thereby permittingsaid first latch member to disengage said catch portion on the movable member and allow said movable member and said contact to move to open circuit position, and means for holding said second latch member out of latching engagement with the catch on said first latch member at least until shortly before said first latch member is re-engaged with the catch portion on the movable member.

l2. In a circuit interrupter, a contact movable to open and close the circuit, a member movable upon actuation of said contact, means for biasing said Contact and said movable member to move to open-circuit position, a latch member engageable with said movable member, a second latch member engageable with the first said latch member for holding it in engagement with said movable member, a spring having its ends connected to said first and second latch members for biasing both of said latch members, electro-responsive means for causing movement of said second latch member out of engagement with said first latch member and thereby permitting said first latch member to disengage said movable member and allow it and said contact to move to open-circuit position, and means for engaging said second latch member and holding it in disengaged position at least for an interval of time prior to each re-engagement of said first latch member with said movable member.

i3. In a circuit interrupter, a contact movable to open and close the circuit, a member movable upon the actuation of said contact and having a catch portion thereon, means for biasing said contact and said movable member to move to opencircuit position, a pivoted latch member for engaging said catch portion on the movable member and holding said movable member against its bias, said catch portion on the movable member exerting a force on said latch member capable of moving said latch member to disengaged position and the perpendicular distance between the line of action of the force exerted by said catch portion on said latch member and the pivot point of said latch being small, a catch portion on said latch member, a second latch member for engaging said catch portion on the first said latch member and holding the first said latch member in engagement with saidcatch portion on the movable member against the force exerted on the first said latch member and the perpendicular distance between the line of action of the holding force exerted on said first latch member and the pivot point thereof being large, a spring having its ends connected between said first and second latch members for biasing both of said latch members, said spring biasing said second latch member into engagement with the first latch member with a large force and the mass of said second latch member being small whereby the likelihood of said second latch being jarred out of engagement with said rst latch member is made small, electro-responsive means for causing movement of said second latch member out of engagement with said catch portion on the first latch member and thereby permitting said first latch member to disengage said catch portion on the movable member and allow said movable member and said contact to move to open circuit position, and means for holding said second latch member out of latching engagement with the catch on said rst latch member at least until shortly before said rst latch member is re-engaged with the catch portion on the movable member.

WALTER M. AUSTIN.

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