US1589924A - Electric switch - Google Patents

Description

June 22 1926., 1,589,924

w. A. ATWOOD ELECTRIC SWITCH Filed Jan. 24. 1922 3 Sheets-Sheet 1 Fig.1.

Invento": \A/inf i eld A. Atwood,

Macaw by His "Flttor'neg.

June 22 ,1926, 1,589,924

W. A. ATWOOD ELECTRIC SWITCH Filed Jan. 24, 1922 3 Sheets-Sheet 2 In v entov: W'i nfi eld A. Atwoo d;

. W J g His-flttorneg.

June 22 1926 1,589,924

w. A. ATWOOD I ELECTRIC SWITCH Filed Jan. 24, 1922 3 Sheets-Sheet 5 Inv entov:

'W'inffeld A. Atwood,

His flti n ey.

Patented June 22, 1926.

UNITED STATES PATE-NT OFFICE.

WINFIELD A. A'IWOOD, QF SCHENEGTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIC COMPANY, A CORPORATION 01 NEW YORK.

ELECTRIC SWITCH.

Application filed January 24, 1922. Serial No. 531,469.

My invention relates to electric switches and more particularly to circuit breakers of the type having a movable electric current conducting or contact member biased to move to circuit opening position and has for an object to provide an improved circuit breaking device which will be positively held latched in circuit closing position re- 'gardless of shocks or vibrations to which the device may be subjected and irrespective of the nature or extent of such shocks and vibrations. Another object of my invention is to provide for circuit breakers an .improved shock proof latching mechanism operative to reset itself in latching position and positively to hold such position even though subjected to excessive shocks and vibrations.

Where circuit breakers are subject to shocks and vibrations, as is the case. particularly on warships and allied craft, it is absolutely necessary that thecircuit breakers do not open under conditions arising from shocks and vibrations as in so doing continuity of service is interrupted and the possibilities resulting from such interruption of service in times of crisis may be disastrous and appalling. Irrespective of the service in which circuit breakers are used, it is essential for the continuity of this serv ice that conditions other than electrical,such asshooks and vibrations, be not effective to cause the opening of the circuit breakers and the consequently unnecessary interruption of service or in any way to interfere with the normal operation of the circuit breakers. The tendency of the usual latching mechanisms of circuit breakers subject to the effects of shocks and vibrations is to creep, an action which is cumulative in effeet and often results in causing the opening of the circuit breaker at inopportune times. Accordingly I provide by my invention an improved and simplified construction of circuit breaking device which eliminates this cumulative creeping action 'so that circuit breakers are not affected by the influence of shocks and vibrations.

My invention will be better understood from the following description taken in connection with the accompanying three sheets of drawings and its scope will be pointed out in the appended claims.

Figure 1 is a sideelevation of a circuit breaker in circuitclosing position embodying my invention; Fig. 2 is a plan View of a part of the latching mechanism; Fig. 3 is a front elevation of a portion of the latching mechanism; Fig. 4 is a view similar to Fig. 1 showing the circuit breaker tripped and partially moved to circuit opening position; Fig. 5 IS a view similar to Fig. 1 showing the circuit breaker in circuit opening position; and Figs. 6 and 7 are side elevations of modified forms of latching devices.

Referring now in particular to Figs. 1, 4 and 5, I have shown my invention, embodied in an electric switch which for the purpose of illustration is shown as a single pole carbon break circuit breaker although my invention is not limited to a single pole circuit breaker or to a circuit breaker of the type having relatively movable cooperating contacts separable in air. In these figures, the circuit breaker is shown mounted on an insulating base or supporting structure 1 and comprisingrelatively movable contacts includin to stu s 4 and a movable contact or electric current conducting member such as a resilient brush 5 cooperating therewith to control' a circuit through the circuit breaker. As is usual in such devices, the circuit breaker is provided with cooperating secondary and tertiary contacts 6 and 7 respectively, to take the are when the circuit breaker is opened. The circuit breaker also inclu'des an actuating mechanism comprising an operating member, such as a handle lever 8 pivotally connected to a pivotally mounted brush supporting member 9 and to pivotally mounted links 10, the operating member 8 and the links 10 forming a toggle mechanism which in its rigid or thrust transmitting position is preferably underset and biased to collapsing position by the effect of gravity and the strain imposed upon the resilient brush 5 when in the circuit'closing position. a

For holding the toggle mechanism in its rigid or thrust transmitting position and therefore the circuit breaker in circuit closing position, I provide an improved-and simple latching mechanism which is unaffected by shocks, jars or Vibrations. This latching mechanism or locking device comprises a main latching means such as a main latching member or trigger lever 11 preferably pivotally associated with the brush supporting member 9 and an auxiliary latchstationary contacts 2 and 3-sec-ured' in means such as a pivotally mounted auxilhary latching member or looking lever 12 arranged to engage and restrain the main latchin member 11 in latching position and adapte to be operated to release the same to effect the opening of the circuit breaker. This auxiliary latching member 12, as shown, -is mounted independently of the main latching member 11 and is adapted to hold the member 11 in engagement with the operating lever 8. Since the effect of agiven shock or vibration on a small mass can be more readily controlled than the effect of the same shock or vibration on a large mass, the mass of the auxiliary latching member 12 is made relatively small in comparison with the mass of the main latching member 11. Creeping action, usually cumulative in effect, of the latching mecharfism under shocks and vibraations may therefore be more effectively controlled and in fact substantially eliminated. The main latching member 11 is pivoted intermediate its ends and is adapted relea sably to lock the operating lever 8 in closed position. The latching member 11 preferably comprises three rigidly associated arms 15, 14 and 15. The arm 13 is cated at one end, and has pivotally mounted therein a pawl or latch 16 which is biased preferably by a relatively light spring 1'( against a shoulder 18, see Fig. 2, on the arm 13 to the position shown in Figs. 1 and 5, but is free to be turned on its pivot in a clockwise direction, see Fig. 4:- There may also be provided a shoulder or stop 18' on the lower side of the bifurcated portion of arm 13 to limit the clockwise rotation of the latch 16, this shoulder 18 also serving to restrain or hold one end of the spring 17. The latch 16 is arranged to be engaged by a biased member such as a catch 19 associated with the operating member 8 and mounted preferably in a hollow portion thereof and biased outwardly by a relatively strong spring 20 so that the operating member 8 and its associated catch 19 form substantially a single member, the movement of the catch 19 being limited in either direction by any suitable lost motion means such as a pin 21 mounted in the operatin member 8 and passing through a slot 22 in the catch 19. The latch 16 and arm 13 therefore I form a toggle mechanism which in its rigid or thrust transmitting position, see Fig. 1, is underset, the point of en agement of the latch 16 and the catch 19 eing above the line joining the pivotal points of the main latching member 11 and the latch 16. Consequently with the parts in the position shown in Fig. 1., the main latching member '11 being restrained in latching position as hereinafter described, the operating member 8 is restrained to hold the brush carrying member 9 and therefore the brush 5 in circuit closing position, the arm 13 taking the preferably bifur-' naeaeaa greater portion of the strain due to the bias or holding in load of the circuit breaker.

My invention is, however, not limited to the particular form of latch and catch above described as I may use modifications such as illustrated in Figs. 6 and 7. As shown \in Fig. 6, the main latching member 11 ma be provided with an arm 13 having a late ing portion 23 arranged to engage a corresponding portion on a catch 19 and preferably shaped, or biased to release when restraint is removed from themain latching member. Alternately, as shown in Fig. 7 the main. latching member may be provided with an arm 13 having a roller 24 pivotally mounted on the end thereof and arranged to engage the face of the catch 19" above the line joining the pivotal points of the main latching member and the roller 24 thereby forming an equivalent for the underset toggle mechanism comprising arm 13 and latch 16 and heretofore described.

The auxiliary latching member 12 as shown is pivoted for movement in a plane parallel to the pl 1.118 of movement of the main latching member 11 The locking lever 12 is provided with a notched or latch-engaging portion forming a lug lying in the path of and arranged to engage a catch or lug 25, which may be of hardened steel, mounted on the end of the arm 14 of the main latching member 11, thereby to restrain or look the member 11 against movement in latching \position. The auxiliary latching member 12 is adapted to be operated either manually or automatically to release the main latching member 11. For this purpose, the auxiliary latching member 12 is provided with a depending or tail portion 26 extending into the path of movement of a tripping member or armature 27 controlled by an electroresponsive device operative in response to predetermined abnormal conditions in the circuit controlled by the circuit breaker and comprising in the circuit breaker illustrated a magnetic frame or yoke 28 operatively related to one terminal or contact 20f the circuit breaker as is well known to the art. The armature 27 may be pro vided with a projecting portion 29 preferably non-magnetic, arranged to engage the tail portion 26 of the auxiliary latching member 12 when the armature is moved to tripping position. The projecting portion 29 is also preferably, though not necessarily, arranged to engage the end portion of the arm It of the main latching member 11 immediately following its release b the auxiliary latching member 12 whereby the main latching member 11 is given an added impetus to accelerate its movement from latching position. The electroresponsive device is provided wth means for varying its range ofoperation which as p votally lllli mounted stop member 31 adjustable to control the initial position of the armature 27 in a manner well known to the art. For tripping the circuit breaker manually, the armature 27 is provided with a handle or knob 32 by means of which it may be moved to tripping position.

While the electroresponsive device shown is of the type responsive to predetermined conditions of overload, it is to be understood that my invention is not limited to this means for actuating a tripping member arranged to release the auxiliary latching member 12, the means shown being merely illustrative of one device I may use. Ob-

viously, I may use any means either automatic in action and operative in response to some predetermined condition, or manually operated, the only requisite being that the means be adapted to be operated to release the auxiliary atching member 12. Accordingly, my invention is not limited in 1ts application to circuit breakers equipped w th the particular electroresponsive device shown.

In order to reset the two coo erating main and auxiliary latching or ing members 11 and 12 in latching position and positive- 1y hold them in latching position irrespective of shocks or vibrations whether the circuit breaker is closed or open, I rovide means for yieldingly maintaining t em in locked relation or 0 erative osition such as a single resilient e ementor spring 33 associated with the main and aux-iliary latching members 11 and 12 for simultaneous control thereof and interconnecting them in such a way as to exert on these members torques which may be considered to be approximately proportional to their masses. The spring 33 is connected to the arm 15 of main latching member 11 and to the auxiliary latching member 12 so that the points'of connection and the axis of rotation of the auxiliary latching member 12 are ,not coplanar. Since the effective force of the spring 33 in any position of the breaker is the same on both the main and auxiliary latching members, the effective torques exerted by the spring on these members will be proportional to the effective lever arms through which the force of the spring is exerted. Consequently there.

exists a relatively large torque tending to turn the main latching member 11 counterclockwise, that is, to restrain it in latching position and a relatively small torque on the au iliary latching member 12 tending to tur it clockwise, that is to hold it in restraining position. The spring 33 is therefore effective to prevent creeping of the latching members under shocks and vibrations since the effect of shocks and vibrations on the relatively small mass of the auxiliary "latching member 12 can be effectively controlled by a smaller counter effect, such as the torque to which it is subjected, than the counter effect such as the greater torque to which the main latching member is .subjected.

Although the spring 33 is connected to exert a torque on the auxiliary latching member 12 to bias the same to latching position, this torque due to the relatively small mass of the auxiliary latching member 12 can be so small and yet effective to prevent tripping of the circuit breaker under the eflect of shocks and vibrations, as to require but a very small force to move the auxiliary latching member 12 to release the main latching member 11. The shape of the notched portion of the auxiliary latching member 12 and the catch 25, that is to say the angle of latching engagement may be changed provided the strength of the. spring 33 or its relative connections to the main and auxiliary latching members or both are changed.

Referring now to Fig. 1 in which the parts are shown in circuit closing position, it is clear that, when the armature 27 has been moved to tripping position, see Fig. 4, whether; auxiliary latching member 12 is actuated to release the catch 25 on the arm 14 of the main latching member 11 which may also have its movement in tripping direction assisted or accelerated by having the armature 27 arranged to strike, in the case illustrated, the end of arm 14 or catch 25' subsequently to the release of this catch by the auxiliary latching member 12 as heretofore described. The main latching memberll, now being free to move clockwise except for the bias of spring 33 which is relatively small as compared with the bias of the circuit breaker operating mechanism under the flexure of the brush 5 and the effect of gravity, permits the collapsing of the toggle mechanism comprising arm 13 and latch 16 thus allowing the to gle mechanism comprising links 10 and operating member 8 to collapse. The latch 16 is thus caused to turn clockwise against the bias of the relatively li ht spring 17 by the catch 19, see Fig. 4. his causes the main latching member 11. to be turned clockwise on its pivot producing an additional stretch and storing more energy in the spring 33. As the main latchin member 11 -1s turned clockwise, the catch 25 on the arm 14 thereof moves along the inneredge of the auxiliary latching member 12, as shown in Fig. 4. As soon as the catch 19 leaves the latch 16 the additional energy stored in the spring 33 turns the main latching member 11 counterclockwise into the position shown in Fig. 5, a lug 34 on the main latching memautomatically or manually, the.

ber 11 coming to rest against a stop 35 on a slight taper which provides a mechanical advantage for the force of the spring 33 whereby the spring is rendered more effective in restoring the latching members 12 and 13 to latching position.

The lug 34 and stop 35 are preferably arranged to permit a slight overtravel of the main latching member 11, that is for it to turn counterclockwise on its pivot somewhat beyond the position occupied when the circuit breaker is closed. In this position, the shoulder of the notched portion of the auxiliary latching member 12 and the catch 25 are somewhat separated as shown in Fig. 5. This construction is such as to insure a positive latching engagement of the auxiliary latching member 12 and the catch 25 upon the closing movement of the circuit breaker. As soon as the catch 19 clears the latch 16, the latter immediately returns to the position shown in Fig. 5 under the bias of spring 17. Upon movement of the operating member 8 in a direction to close the circuit breaker, the biased catch 19 travels or trails across the upper face of the latch 16 causing the main latching member 11 to turn clockwise thus setting the catch 25 squarely against the .notched portion of the auxiliary latching member 12. As the catch 19 moves over the face of the latch 16, the catch 19 is forced inwardly in its mounting until it travels over the nose of the latch 16 and snaps into engagement therewith, as shown in Fig 1, to hold the circuit breaker closed as long as the main latching member 11 is restrained in latching position by the auxiliary latching member It is therefore clear that circuit breakers constructed in accordance with my invention'will not be affected by shocks, jars .or vibrations and consequently will stay closed and therefore maintain continuity of service under the efiects of such conditions.

Although I have shown and described my invention in considerable detail, I do not wish to be limited to the specific details thereof, as shown and described, but may use such modifications, substitutions, or equivalents thereof, as are embraced within the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of-the Unitedstates, is

1. 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 adapted to hold said main latching means in latching position, and a resilient connection between said main and auxiliary latching means arranged to bias said latching means to latch engaging position.

2. An electric switch comprising a movable contact member biased to circuit opening position, an operating member adapted neaaoaa to be operated to move said contact member to circuit closing position. main latching means for restraining saidoperating member to cause the same to hold said contact member in circuit closing position, auxiliary latching means adapted to hold said main latching means in latching position, and a resilient connection between sald mam and auxiliary latching means arranged to bias said latching means to latch engaging position.

3. An electric switch comprising a movable contact member biased to circuit opening position, an operating member adapted to be operated to moye said contact member to circuit closing position, a main latching member for restraining said operating member to cause the same to hold said contact member in circuit closing position, an auxiliary latching member 0 relatively small mass in comparison with the mass of said main latching member adapted to hold said main latching member in latching position, and a spring interconnecting said main and auxiliary latchin members and arranged to bias said latching members to latch engaging position.

4. An electric switch comprising a movable contact member biased to circuit opening position, a main latching member for restraining said contact member in circuit closing position, an auxiliary latching member arranged to engage and restrain said main latching member in latching position and adapted to be operated to release said main latching member thereby to effect the movement of said contact member to circuit opening position, and resilient means associated with said main and auxiliary latching members for biasing said latching members to latch engaging position operative to able contact member biased to circuit open-- ing position, an operating member adapted to be operated to move said contact member to circuit closing position, a main latching member associated with said contact member for restraining said operating member to cause the same to hold said contact member in circuit closing position, a biased catch member associated with said operating member and arranged to engage said main latching member upon movement of said operating member in circuit closing direction, an

auxiliary latching member arranged to engage and restrain said main latching member in latching position and ada ted to be operated to release said main latc ing member thereby to elfect the movement of said contact member to circuit opening position, and means comprising a resilient element interconnecting said mainand auxiliary fnounted on said operating member and arranged to engage said main latching member upon movement of said operating member in circuit closing direction, a pivotally mounted auxiliary latching member arran ed to engage and restrain said main latc ing member in latching position and adapted to be operated to release said main latching member thereby to efi'ect the movement of said movable member to circuit opening position, and means comprising a resilient element interconnecting said main and auxiliary latching members for exerting relatively large and small torques on said main and auxiliary latching members -re spectively and subsequently to the release of said main latching member for moving said latching members to latching position.

7. An electric switch comprising a movable contact member biased to circuit openmg position, a main latching member for,

restraining said contact member in circuit closing position, an auxiliary latching member having a relatively small mass in comparison with the mass of said main latching member arranged to engage and restrain said main latching member in latching osition and adapted to be operated to re ease said main latching member thereb to eifect the movement of said contact mem er to circuit opening position, and means comprising a spring interconnecting said main and auxiliary latching members and arranged to exert relatively large and small torques on said main and auxiliary latchin members respectively for biasing said late ing members to latch engaging position.

8. In combination with an operating lever, a locking device therefor comprising a trigger lever pivoted ad'acent to one of its ends and, at its other en adapted to eifect looking engagement with the o erating lever, a locking lever mounted independently of the trigger lever and adapted to hold the trigger lever in engagement with the operating lever, a single means for yieldingly maintaining the levers in operative position, i

and means for moving them to inoperative position.

9. The combination with a movable switch member, of a pair of latch members, one of which engages the switch member and releasably retains it in closed position and the other of which engages the first latch member and releasabl tion, and a singlia means for biasing both latch members in operative latched position.

10. A locking device comprising a trigger lever pivoted intermediate its ends, a looking lever pivoted for movement in a plane parallel to the plane of movement of said trigger lever, a lug on the locking'lever no mally lying in the path of a lug 0n the trigger lever to lock the trigger lever against movement, and a single means for yieldingly maintaining said levers in locked relation.

11. In combination with an operating lever, a locking device therefor comprising a trigger lever pivoted ,intermediate its ends and, at one end, adapted to effect locking engagement with the operating lever, a lock- 1 ing lever mounted independently of the trigger lever and adapted to hold the trigger lever in engagement with the operating lever, a single means for yieldingly main taining the levers in operative position, and means for moving them to inoperative position.

"12. A locking device comprising in combination a movable member, two cooperating locking members, one of which is adapted releasably to lock the movable member against movement and the other of which is adapted normally to lock the first locking member against movement, a spring interconnectin said locking members arranged to bias said first locking member to engage said, movable member and to bias said other locking member to lock said first locking member against movement 13. The combination with a switch-operating lever and a pivoted latch member for releasably retaining the operating lever in closed position, ofan auxiliary latch member mounted independently of the first latch member for releasably retaining the first latch member in operative latching position, and a spring for biasing both latch members in latching position.

In witness whereof, I have hereunto set my hand this 23rd day of January, 1922.

WIN FIELD A. ATWO OD.

retains it in latched posi-

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