US1954634A - Circuit breaker - Google Patents

Description

April 10, 1934. N LEMMON ET AL CIRCUI T BREAKER Filed March 10, 1932 2 Sheets$heet l April 10, 1934. G. N LEMMON ET AL 1,954,634

C IRCUI T BREAKER Filed March 10, 1932 2 Sheets-Sheet 2 INVENTOR Patented Apr. 10, 1934 PATENT OFFICE CIRCUIT BREAKER George N. Lemmon, Homewood, and Harry Knowles, Birmingham,

Ala, assignors t Southern States Equipment 00., Birmingham,

Ala.

Application March 10, 1932, Serial No. 597,945

14 Claims.

This invention relates to circuit breakers. More particularly it relates to circuit breakers of the fusible type, in which the circuit is ruptured, upon occurrence of an overload, by melting of a fusible link, and the circuit is automatically reestablished several times by the successive insertion of new fuses into the circuit.

This invention is a development of the invention described in the copending application of George N. Lemmon Serial No. 474,335, filed August 11th, 1930.

It is an object of this invention to provide an improved circuit breaker of the above type, in which the rupture of any of a plurality of associated fuses will cause a new fuse, held in reserve, to be inserted in the line, automatically.

Another object is to provide a device of the above type which is suitable for high voltage service.

23 Other objects and advantages of my invention will become apparent as the invention is described in connection with the accompanying drawings:-

In the drawings:--

Figure 1 is a side elevation view of the invention.

Figure 2 is a front elevation view of the invention shown in Figure 1 but on a larger scale and with the insulators and base omitted.

Figure 3 is a fragmentary detail view partly in section, of the left side of the right fuse-holder mounting and its associated latches, shown in elevation. The section is along line 33 of Figure 2.

Figure 4 is a fragmentary detail view, partly in section of the right side of the center fuseholder mounting and its associated latches, shown in elevation. The section is along line 4-4 of Figure 2.

. Figure 5 is a fragmentary detail view of the 40 left side of the left fuse-holder mounting and associated latches.

Figure 6 is a fragmentary detail view of the right side of the right fuse-holder mounting.

Figure '7 is a view of a central section taken through the lower end of the fuse-holder, showing the fuse unruptured.

Figure 8 is a view similar to Figure '7 but with the fuse ruptured.

-' Figure 9 is a front view in elevation, of the latches for the fuse-holder mountings, and the support for the latches. In this figure, for the sake of clearness only, the lower portion of the fuse-holders and their mountings are outlined in dotted lines.

Figure 10 is a detail view in side elevation of the right side of the latch at the right end of the device.

Figure 11 is a perspective view-of a catch.

Referring to the drawings, the device is mounted on a vertical base 1 upon which are mounted two pin type insulators. Upon these insulators are secured metal castings 2 and 3 forming supports for the current-carrying and circuit-breaking parts of the invention. One power line may be connected to each of these castings. The upper casting 2 comprises a cap 49, cemented to the top of the insulator, and a plate with three spaced pairs of parallel lugs 50 upstanding from the surface of the casting. Between the lugs of each pair is secured a brush contact 15 which is inclined downward for engagement with a movable latch-contact hereinafter tobe described. Pivotally mounted upon each pair of lugs 50 is a latch 4.

For engagement with each of the latches 4 and brush contacts 15, there is provided on the swing ing end of each of three identical pivotally mounted insulating tubes 9, 10, 11 a bracket or terminal 12 which embraces the tube end and has a portion extending laterally therefrom toward the brushes 15. Upon the end of the laterally extending portion is pivotally mounted a latchcontact 13 having an upwardly directed tongue which extends into a slot 14 in the central portion of the top of the latch 4. These latch contacts also engage brush contacts 15.

Upon the other end of the tubes 9, 10, 11, there are secured terminals 22 which embrace the tube end and are provided with screws 28 for holding an end of a taut fusible link 40 extending through thetube and having its other end secured to one end of the latch-contact 13 to pull that end of the latch-contact toward the tube end and prevent (so long as the fuse link 40 is intact) rotation of the latch-contact during its engagement with latch 4. The terminals 22 are also provided with trunnions32 upon which the tube pivots as hereinafter described. The tubes 9, 10, 11 with their terminals may be termed fuse-holders.

The construction of the fuse-holders and the contacts and latches with which the swinging ends of the fuse-holders cooperate as thus far described, is more or less conventional. The novel mounting for the fuse-holders, and the means for causing successive interposing of the fuses in the circuit will now be described.

The lower casting 3 comprises a cap 52, cemerited to the top of the lower insulator, and a plate with four approximately equally spaced arms 53 extending perpendicularly from the face of the plate. Two of these arms are at opposite edges of the plate and the other two are in the central portion thereof.

.Each of the three fuse-holders is supported for pivotal movement in a carriage. All the carriages, indicated generally by numerals 6, 7, and 8 in the drawings, are alikeand all are pivotally mounted on a non 'rotatable rod 5 extending parallel to the casting 3 and through the ends of the arms 53. The carriages are U- shaped and their side plates are dissimilar. The form of the right side plates may be seen in Figures 4 and 6 while the form of the left side plates may be seen in Figures 3 and 5. The space between the side plates is bridged by a web 38 and a cross bar 39, the latter serving to limit the opening movement of the fuse-holder as will hereinafter more fully appear.

Each carriage is provided with open bearings or seats 54 for the trunnions '32 of the fuseholder. The fuse-holders may be mounted with their trunnions in said bearings by the use of a common switch-stick with an insulating handle, the end of which engages in the aperture 55,0f the upper terminal 12.

The carriages 6-, 7', 8 can occupy two positions of rest. One position, which may be termed the reserve position, is that which the carriage 8 occupies in Figure 3. The other position, which may be termed the active position, is that which the carriages 6, 7, and 8 occupy in Figures 4,

5 and 6.

To urge the carriages 6, 7, 8 toward active position there is provided for each carriage a spring 17 coiled around the rod 5 and having one end anchored to a carriage (see carriage 6, Figure 2) and the other end anchored to a cylindrical housing for said spring 17, the housing 16 being fixed to the rod 5. As'illustrated these springs 17 and housings 16 are adjacent the left sidesof the carriages.

To hold the carriages normally in reserve position, there is provided on the left side of each carriage in a position on the opposite side of the rod 5 from trunnion seat 54, a laterally projecting arcuate lug 20 with a lip, that is engaged by a detent 41 which is part of a locking member now to .be described.

Identical locking members 19, 19, are provided for the carriages 7 and 8 and each is formed and arranged to be operated by movement of the,

carriage adjacent to the one it locks in reserve position. Each locking member is pivotally mounted upon a shaft 18 parallel to rod 5 and mounted in the arms 53 between the rod 5 and the face of casting 3. Each locking member comprises a detent 41, a limiting stop or extension 43 approximately 90 in advance of the detent 41 in the direction to limit downward rotation of, the locking member, and a curved arm 21 laterally ofiset at its middle in the direction away from the detent 41. Each arm 21 extends -'into the path of a cam 36 which is located on the right trunnion of each fuse-holder, so that under certain conditions (hereinafter set forth) when the fuse holder rotates the cam 36 engages arm 21 rotating it about shaft 18 and toward the casting 3 thus releasing the detent 41 fromengagement with the lug 20 on the next carriage,

and allowing the spring 17 for that carriage to rotate it to active position. Y

It will. be apparent that the construction just described will only work for adjacent carriages. In order that the carriage 8 may release carriage 6 which is remote from it, there is fixedly mountof the link 34, as it will do under certain conditions hereinafter detailed, it will rock the link 34 idly about its pivot, but when the cam 36 engages the under side of link 34, as it will do under certain other conditions, it will 'cause link 34 to rotate shaft 18. The other end of the shaft 18 i. e. the end near carriage 6, has on it a locking member 19' with a detent 41 and limiting stop 43 just like the detents 41 and stops 43 on the locking members 19, both in structure and function. Thus rocking of the shaft '18 rocks detent 41 disengaging it from lug 20 of carriage 6 freeing that carriage for rotation, under the influence of its spring 17, from reserve to active position.

In order to bias the lever 34, 34' and also shaft 18- and detent 41 into position wherein detent 41 engages lug 20 on carriage 6, there is provided a coiled spring around the end of shaft 18 one end of which spring is anchored to the casting 3 while the other end presses against the lever 34, 34'. This spring also serves to hold the inner end of the link 34 against its seat in link 34. See Figure 10.

The purpose of rotating the carriages from reserve to active position is to carry a new fuse into circuit-making position (i. e. the position in which fuse-holder 10 is shown in Figure 2) after a formerly encircuited fuse has been ruptured. In

order that a carriage may do-this there is proriage. To the end of link 25 away from hub nose 250 is pivotally connected the end of a link 26 whose opposite end is pivotally connected to a triangular link 27 which is pivotally mounted on the end of the terminal 22. v

The fuse 40 passes around a boss on-the link 27 and holds one edge of that link against the end of the tube, so long as the fuse is intact, (see Figure 7). When the fuse is ruptured (Figure 8) the expulsion effect of the rupture moves the link 27 away from the tube end and causes the link 25 to pivot.

By referring to Figures3 and 5 the position of the parts will be observed when a carriage is holding the fuse-holder with fuse intact, in reserve and in active position. In each case the tooth 29 is engaged with the nose 250 thus' holding the fuse-holder against the force of gravity, while the holder is in the reserve position (see fuse-holder 11 in Figures 1 and 2) and causing the fuse-holder to move as a unit, with the carriage when the carriage moves to active position.

'The fuse-holder can occupy two positions of rest while its carriage isin active position. One

position is the circuit closing position, in which which position fuse-holder 9 is shown in Figures land 2.

When the carriage is in reserve position the fuse-holder can occupy the reserve position, in which position fuse-holder 11 is shown in Figures 1 and 2. Or the fuse-holder with its fuse ruptured, can be removed from the carriage while occupying the dotted line position in Figure 3.

In order to insure a good electrical connection between the terminal 22 and the casting 3, brush contacts 24 are provided upon the casting in position to be engaged by a contact face 23 formed on the terminal 22 by an arm extending laterally from the terminal and bent at its central part parallel to the tube.

In order to overcome any. effort of the trunnions 32 to slip out of their bearing seats 54 posts 31 are formed on the casting 3 projecting to the trunnions 32 of each fuse'holder when the fuseholder is in circuit closing position (see Figure 5). These posts 31 serve another purpose, for each may be engaged by a lateral extension on the afore-mentioned catches which hold the fuseholders for movement with the carriages in moving to active position. The engagement of extensions 30 with posts 31 occurs only when a carriage is rotated against its spring 17, past reserve position. When this takes place the nose 250 becomes disengaged from tooth 29 and the fuseholder can drop into the dotted position'of Figure 3. This operation may be employed when it is desired to inspect or change an unruptured fuse. To pullv the carriages against their springs 17 a hook 42 is provided on the right side plate of each carriage. To limit the movement into active position of the carriages there is provided also on the right side plate of each carriage an arm 33 extending toward the casting 3 and which engages with the casting when the carriage attains active position.

The operation of the invention is as follows:

Assuming tubes 10 and 11 to be in the positions shown in Figures 1 and 2 i. e. circuit-making and reserve position respectively; and assuming tube 9 to be in reserve position, (instead of the position in which it is shown in Figure 1) then the circuit will be completed through tube 10. Upon occurrence of an overload or trouble on the line fuse 4O ruptures and the arc'is extinguished by the well known expulsion effect. The destruction of the fuse causes release of latch 13 at the swinging end of the tube, freeing that end of the tube for movement under the force of gravity and the spring effect of the contact brushes l5and. 24, toward fuse-ruptured position (the position of tube 9 in Figures 1 and 2). At the same time, the rupture of the fuse has released links 25, 26, 2? (see Figures '7 and 8) causing disengagement of nose 250 from tooth 29. During the moveof the fuse-holder 10 to .-fuse-ruptured posi on, the carriage 7 remains in active position.

.(See Figure 4 in which the full line position shows the tube half way to fuse-ruptured position, and the dotted lines show the tube resting in fuse-ruptured position). In moving from circuit-closing to fuse-ruptured position, the fuseholder rocks on its trunnions 32 causing the cam 36 to engage arm 2l of the locking member 1.9 which lies between tube 10 and tube 11. This action of cam 36 rotates member 19 causing its detent ll to disengage itself from the lug 20 of the next carriage 8. This disengagement permits spring 17 to act on carriage 8 moving it from the reserve position shown in Figure 3 to the active position carrying fuse-holder 11 with it into circuit-closing position by reason of the fact of the engagement of tooth 29 with nose 250.

Now in case the trouble persisted, the fuse in tube 11 will rupture, and the tube-holder will fall into fuse-ruptured position in a manner, exactly like its predecessor, tube 10. However, in doing this the cam 36 on its trunnion will engage link 34, 34' moving it toward the casting plate 3, rocking shaft 18 and with it looking member 19 whose detent 41 will be disengaged from the lug 20 of carriage 6, thus permitting spring 17 to move the carriage into active position carrying with it the fuse-holder that it is supporting. This again closes the circuit. If new the trouble still persists the fuse in tube 9 will rupture and the circuit will remain open until the trouble has cleared and new fuses are put inplace.

To re-fuse, all the carriages are moved to reserve position by pulling down successively on the fuseholders with a switch stick. This engages all the lugs 20 with detents ll. After removal and replacement of the fuse-holders they will 00- cupy the dotted position of Figure 3. They will then be rotated toward the line terminals into reserve position in which they will be held by teeth 29 engaging noses 250. To put a fuse in circuit it is only necessary to move one of the latches by engaging an arm 21 (or 34) or the tail 19 (or 19) thereof to disengage the lug 20 and detent 41. Any fuse can be put in circuit since by this invention the operation of the fuses is repetitively sequential.

It should be noted in regard to the fuse-holder in carriage 8 that in falling to fuse-ruptured position it carries the cam 36 over the link 34 after having rocked the links 34, 34' to cause release of another carriage. If an attempt were made at this point to swing the tube back up toward closed-circuit position, the lever might be damaged but for the provision of the fabricated type of the lever which permits link 3a to pivot idly until the cam 36 again gets beneath it. It is not necessary to provide fabricated arms on the looking members 19, for the reason that the arms 21 of these members are long and the earns 36 never get over them.

From the foregoing it will be apparent that I have provided. an efficient repeating circuit breaker of the fusible type in which all the fuses can be inserted in the circuit successively no matter which fuse is at first placed in circuit. Also, ruptured fuses may be replaced without disturbing an encircuited fuse or the sequence of operations of the device.

Many modifications within the scope of my invention will occur to thoseskilled in the art, therefore I do not limit myself to the specific form of the invention shown in the drawings.

We claim:

1. In a circuit breaker, a pivotally mounted carriage movable into circuit-closing position, a tubular insulating container pivotally mounted on said carriage, a flexible conductor within said container, together with spring means to bias the carriage towards circuit closing position.

2. In a circuit-breaker, a plurality of movable insulating tubular containers mounted upon a common base, flexible conductors within the containers, separate spring means and separate latch means for each container whereby each of the said conductors successively is movable into and out of circuit-closing position.

3. In a circuit breaker, a plurality of carriages pivotally mounted upon a common metallic base, a plurality of insulating tubes containing flexible conductors and pivotally supported in the said carriages and movable into and out of circuitclosing position.

. cult-closing position.

5. In a circuit breaker, two spaced insulated terminals, a carriage pivotally mounted upon one of the terminals a tubular insulating container supported by said carriage and movable from open-circuit to closed-circuit .position, a flexible conductor within said container, together with spring means to bias said carriage toward closedcircuit position, and latch means to restrain the action of said spring means.

6. In a circuit breaker a plurality of tubular insulating containers movably mounted upon a common base, flexible conductors within the containers, separate springmeans to bias each container towards closed-circuit position, and automatic means to bring the containers successively into and out of closed-circuit position.

'7. In a circuit breaker, a plurality of insulating tubular containers, flexible conductors therein, means to hold one of the conductors and its container in circuit-closing position, and means to hold another of the said conductors and its container in a reserve and open-circuit position, together with automatic means operable upon overload in the circuit to remove the flrst'container, with the aid of gravity, from its circuitclosing position and immediately thereafter to move the other container, against the force of gravity, from its reserve position into a circuitclosing position.

8. In a circuit breaker, two spaced insulated terminalsfa plurality of pivotally mounted conductors supported upon one of the said terminals,

means to hold one of the said conductors in a position to span the gap and close the circuit between the terminals, means to hold a second conductor out of circuit, together with automatic means operable upon overload in the circuit to remove the first conductor from the circuit, and spring operated means actuable immediately thereafter to place the second conductor in circuit.

9. In a circuit breaker, two spaced insulated terminals, a plurality of tubular insulating fuse containers pivotally mounted upon one terminal and movable into and out of circuit-closing position, means to hold one container andits fuse in circuit until the fuse is blown, and automatic means operable immediately thereafter to move a second container and its fuse into circuit-closing position, said automatic means including a movable member extending a substantial distance across the pivot-carrying terminal and being movable about an axis that is transverse to the direction of current flow.

10. In a circuit breaker, a plurality of carriages pivotally mounted upon a common metallic base, a plurality of insulating tubes containing flexible conductors and pivotally supported in the said carriages and movable successively from circuit-completing position to open-circuit position.

11. In a circuit breaker, a plurality of insulating tubes each containing circuit interrupting means, insulated mounting means pivotally supporting said'tubes, means causing a tube upon circuit interruption therein to move out of circuit-closing position, means to move each of the remaining tubes into circuit automatically and successively upon continued circuit interruptions irrespective of which tube was first in circuitclosing position.

12. In a circuit breaker, a plurality of insulating tubes each containing a flexible conductor for interrupting the circuit within the tube, insulated mounting means pivotally supporting said tubes, and means for moving each of said tubes into circuit-closing position one at a time and one after another irrespective of which conductor is first in circuit, and means causing a tube to move out of circuit-closing position upon circuit interruption therein, the movement of 05 said tube out of circuit-closing position causing another tube to move into circuit-closing position. i

13. Ma circuit breaker, a plurality of insulating tubes each containing a flexible conduce tor for interrupting the circuit within the tube, an insulated support upon which said tubes are pivotally mounted and means for moving each of said tubes into circuit-closing position automatically one at a time and one after another irrespective of which'conductor is first in cir-' cult, said means being set in motion by circuit interruption within the encircuited tube.

14. In a circuit breaker, a plurality of carriages pivotally mounted upon an insulated terminal, a plurality of insulating tubes each containing flexible conductors for interrupting the circuit within the tube, said tubes being pivotally supported in said carriages, and means for moving each of said tubes into circuit-closing 5 position automatically one at a time and one after another irrespective of which conductor is first in circuit, said means being set in motion by circuit interruption within an encircuited tube. 1

GEO., N. LEMMON. HARRY H. KNOWLES.

Images