US2053248A - Automatic reset circuit breaker - Google Patents

Description

2 Sheets-Sheet l sept- 1, 1936. w. H. FRANK I AUTOMATIC RESET CIRCUIT BREAKER Filed April 2l, 1933 ATTORNEY Sept. 1, 1936. w. H. FRANK 2,053,248

AUTOMATIC RESET CIRCUIT BREAKER Filed April 21., 1953 2 Sheets-Sheet 2 :nun

I INVENTOR.

ATTORNEY.

Patented sept. 1, 1936 UNITED STATES PATENT OFFICE AUTOMATIC RESET CIRCUIT BREAKER Application April 21, 1933, Serial No. 667,152

8 Claims. (CI. 200-116) This invention relates to' automatically resetting circuit breakersv and can best be understood with reference to our copending application Serial No. 667,149, filed April 21, 1933.

In the prior application there is disclosed an automatically resetting circuit breaker including a spring motor which tends to move the contact parts to and from contact making and contact breaking position, the movement being controlled by the condition of an overload release part, namely, a bimetallic warping element. As has been brought out in the prior application, if the overload on the line is a continuous one, the cycle of overload release and automatic reset will continue indefinitely or until the spring has run down to such an extent that it is too weak to function.

It appears desirable, in order to prevent the spring from becoming run down too much, and also in order to prevent injury to the breaker contacts due to what might otherwise be a continuous cycle of closing and opening of the breaker, to provide means to limit the number of cycles so that not many cycles of opening and closing will take place, and the invention aims to provide such means.

In a preferred embodiment of the invention, the number of cycles is controlled by the number of teeth upon a toothed disc and for purposes of illustration, we have chosen to provide a three tooth disc which will permit three overload release operations and automatic resetting operations of the circuit breaker to take place, after which the breaker will remain permanently open, 35 until reset manually vby the operator, who will of course be instructed, not to reset the breaker manually until after the overload has been removed from the line. 'In other words, two cycles of overload release and automatic reset will take 40 place, followed by an overload release which holds the parts in open circuit condition until the operator manually resets the breaker.

Other objects of the invention will presently appear upon reference to the following detailed description of the preferred embodiment, which embodiment is shown in the appended drawings. In these drawings- Fig. 1 is a top plan view of the embodiment with cover removed.

Figs. 2, 3, and Llare clarified sectional views, as if on lines 2-2, 3-3 and 4-4 of Fig. 1.

Fig. 5 is an end sectional view, as if on line 5-5 of Fig. 1.

Figs. 6, '7, and 8 are clarified sectional views, as if on lines 66, 1-1 and 8-8 of Fig. 5.

Fig. 9 is a view similar to that of Fig. 6 but showing manual switching means.

The breaker parts are mounted upon a base I I of insulating material which is closed by a cover IIa, which may be also of insulating material, the cover having four slots through which project the four manually engageable parts of the breaker, namely, the spring motor winding drum I2, the manual resetting handle I3, the manual control handle I4, and'the manual reset latch handle I5. The breaker parts will now be described specifically.

Pivotally mounted on an axle pin I 6, to and between the upstanding fixed frame plates Il, is the breaker contact arm I8 having a contact I9 for engaging the fixed line contact of the breaker. Pivotally connected by an axle pin 2| to upstanding parts of the breaker contact arm I8 are connecting rod links 22, which at their upper ends are connected to a crank 23, formed on the breaker operating shaft 24, the latter being trunnioned in aligned bearing holes of the upstanding frame plates I 'I.

It is observed that rotation of the operating shaft 24 operates, through the medium of the crank 23 and the connecting rod links 22, to move the contact arm I8 to and from contact making and breaking position.

On the rear end of the operating shaft, opposite the end bearing the crank 23, is a pinion 26 in constant mesh with a gear 2l keyed to a jack shaft 28 which is parallel to the operating shaft and which is also disposed in upstanding frame plates, referenced 29. 'I'he ratio of gear 2l to pinion gear 26 is 3 to 1 so that each 120 rotation of gear 2l rotates pinion gear 26, 360. Rotatably journalled on the jack shaft is theA previously mentioned Winding drum I2, the latter containing a clock spring 30 wound upon the end of the jack shaft and having one end fixed thereto and the other end fixed to the drum at 3|. This spring tends to rotate the jack shaft counter-clockwise, Fig. 4, and its influence is opposed by stops about to be described. The drum is prevented from rotating clockwise by a ratchet 32 fixed thereto and engaged by a detent 33 fixed to the frame plate 29.

The stops are in the nature of teeth 36, 3l formed on the inner edge of a reciprocable U- shaped holding plate 38, the teeth facing in opposite directions, as will be observed best from Figs. 6 and 9. The holding plate 38, at its-left`A a thermal element T, of the conventional bimetallic inverted U type, the cross plate of the latter being insulated, by insulation 40, from the angle piece 4I which connects the thermal element and the holding plate 38. The thermal element is mounted upon a block 42 of insulating material, and one end of the thermal element is connected to the Contact arm I8 of the breaker by a suitable lead (not shown) and the other is connected to the load conductor, the contact arm I8 and the thermal element T thus being placed in series with the load.

The right hand end of the holding plate 38 is pivotally connected by a floating pivot pin 44 (Fig. 6) to the upper end of a floating link 45, the lower end of the latter being connected by a fixed pivot 46 to a frame plate 29.

In the plane of the holding plate 38 is a three tooth disc 58 having equally spaced 120 teeth 5Ia, 5Ib, 5Ic selectively cooperating with the teeth 36, 31 kof the holding plate as the disc 50 rotates and as the holding plate 38 reciprocates, it being observed that thevdisc 50 isY keyed to the jack shaft 28 previously mentioned.

The holding plate 38 and the disc 58 constitute the holding parts of the breaker holding mechanism and the operation of these parts will be described later in detail.

Also keyed-to the jack shaft 28 and positioned between the gear 21 and the three tooth disc 5I),` is a disc 52, having Ain its edge a notch 53 vproviding a single tooth 54 xedly positioned 'to be in line-with one of the teeth of the three tooth disc 56. In the plane of the disc 52 is a manual resetting lever 55 (Fig. 8) whose handle I3 has previously been mentioned. The lever 55 is pivoted on the fixed pivot 46 which journals the link 45 of the holding plate, and is vconstantly urged to rotate about this pivot, in a counterclockwise direction, by a coiled spring' 56 which bears against a frame part 51 that connects the frame plates I1. The edge 58 of the lever 55 nearest the disc 52 is provided with a notch 58 adapted to cooperate in a `manner about to be described with the tooth 54 of the disc 52. The disc 52 and the lever 55 constitute the critical parts of the manual resetting means and the operation of these parts will later be described in detail.

Also keyed to the jack shaft 28 and forwardly of the gear 21 and of the frame plate 29 which supports the jack shaft 28 is a second three tooth disc 60 (Fig. '1) identical in construction with the three tooth disc 50 and having like it, three teeth 6I, disposed at all times in alignment with three teeth of the disc 50. In the plane of the disc 60 is a manual reset latch plate 62 whose handle part I5 has previously been mentioned. The latching plate 62 is reciprocably supported on the frame plate I1 by means of slots 63 formed in the plate and receiving pins 64 projecting from the frame plate I1, the construction being such that the latching plate 62 can reciprocate to and from the disc 60, in the plane of the latter. The edge 65 of the latching plate 62 adja-v cent the disc 60 is formed with a shoulder at 66 for cooperation with one of the teeth 6| of. the disc 60, in a manner about to be described. The disc 60 and the plate 62 constitute the manual reset latch means and the operation of these parts will presently be described in detail.

The block 42 upon which the thermal element "T is fixed is disposed on key and groove runways in a depression 10 in the upper surface of the base and is so proportioned as tobe slidable laterally, as in Figure 9, to move the thermal element T and the holding plate 38, as desired. For sliding the block 42, there is provided a manual control lever 1I (Fig. 9) whose handle part I4 has previously vbeen mentioned. The lever 1I is pivoted to the base o-n a cross shaft 12 which is operatively connected to the block 42 by an arm 13 projecting upwardly therefrom and 'fixed thereto and engaging in a groove in the base of the block. A spring detent 14 is positioned in the base and is adapted to cooperate with one or another of the notches 15 in the base of the block, to define positions of the block and of the parts connected thereto. The lever 1I and its associated parts constitute a manual control means whose operation will presently be described.

The various operations of the breaker parts will now be described in detail.

Overton@ release and automatic reset Assume the parts to be in the on position of Fig. 2, with the rst cycle of operations about to begin. At this time, the thermal element T will occupy its normal unwarped or extreme right hand positionand the stop 36 ofthe holding plate 38 will be in the path of the teeth 5| of the disc 50, the tooth 5I a as shown engaging the stop 36 so that the jack shaft 28 is ymaintained at rest. The operating shaft 24 will therefore be also .at rest and in such a position that the contact arm I8 is horizontally disposed and is in on position. `Tooth 54 of disc 52 will be in line with tooth 5Ic of disc 58, or 300 away from tooth 59 of lever 55. Stop 31 of holding plate 38 will be 60 away from tooth 5Ib.

When an overload or short circuit occurs, the thermal element T warps to the left, pulling the holding plate 38 with it towards the left. Stop 36 therefore releases the disc 50 andnthe operating spring 30 in drum I2 rotates the jack shaft and the parts thereon counter clockwise, Fig. 2. Such rotation, transmitted through the gear 21 and the pinion 26, rotates the operating shaft 24 rapidly to raise the contact arm I8 and rupture the circuit.

When the holding plate 38 moved to the left, due to the warping of the thermal element T, it not only caused stop 36 to release tooth 5Ia of the disc, but it also moved the oi stop 31 into the path ofI rotation of the teeth 5I. 'Ihe stop 31 therefore is engaged by the tooth 5Ib which is 120 in advance of the tooth 5Ia which had been in engagement withthe stop 36. The stop 31 therefore limits rotation of the disc 50 and all of the parts of the breaker at this time to 60, the parts coming to rest in the position of Fig. 6, which is the position of the parts on overload release.

When the thermal element T has cooled sufficiently, it warps back to the position of Fig. 2 and reciprocates the ho-lding plate 38 towards the right. Stop 31 releases the disc which then rotates, such rotation being translated through the gear and pinion into rotation of the operating shaft and movement of the contact arm I8 back to the on position, closing the circuit. Stop 36 in the meantime, had moved into the path of rotation of the teeth 5I of disc 50 and is engaged by the tooth 5Ic, to limit such return rotation of the disc 50 to 60, the disc 50 rotating 120 in the foregoing cycle of overload release and automatic reset. The pinion gear 26 as previously stated is in 1 to 3 ratio to gear 21.

way as they' had moved on `the ilrst"'cycie, and the In the event that the overload is still on the line, or whenever an overload or short circuit comes on to the line after the rst complete cycle of overload release and automatic reset has taken place, a second overload release and automatic reset cycle of movement of the parts is accomplished, the parts moving in exactlythesame parts 'come'to rest in a position like that of Fig. 2, but with Vtooth 5Ib against stop 36, 240 rotation having been attained at the end of the second cycle.

It the overload is still on the line, or if an overload or short circuit comes on to the line, after the second cycle is completed. a third overload release movement of the parts occurs, the parts moving in exactly the same way as they had moved on the ilrst two cycles, and coming to rest in the open circuit or overload' release position of Fig. 6, but with the tooth 5Ic under stop 31 of plate 38,

Manual reset It will be remembered that the ilrst two cycles of movement of the parts terminated in automatic reset. The third cycle will not so terminate, however, as will now be brought out.

When the thermal element T" cools suiliciently to return to the normal or unwarped position, it moves holding plate 38 so that stop 31 releases the tooth 5Ic of disc 50 which it had been holding at this time. Such release, however, does not permit a return of the parts to closed circuit position for automatic reseton the third cycle, as it would on the ilrst two complete cycles, because of the operation of the disc 52 and the manual reset lever 55, which operation will now be described. i

At the beginning of the nrst cycle, the tooth 54 oi' disc 52, which tooth is inline with the tooth 5Ic of disc 5l, was 300 away from shoulder 59 of lever 5l. This tooth 54 moves 120 on the rst cycle, a second 120 on the second cycle, and then 60 on the overload release operation of the third cycle,

' or 300 in all, up to this point. The disc 52 thus rotates 300 during the ilve separate movements which have taken place to this time on two-andone-hali' cycles. During this movement o! the disc 52, the edge thereof, which edge is in engagement with the edge ll of the manual reset lever Il, holds such lever outwardly and against the influence of the spring 56.

However, at the end of the 300 rotation oi.' the disc 52 the notch 53 of the disc aligns with the notch in the edge 5l of the manual reset lever, (Fig. 8) permitting the spring 5i to function and move lever 55 into such position that the lever tooth 59 engages tooth 54 to restrain further rotation of disc 52. This restraint acts upon the `jack shaft 2l keyed to the disc 52, and translated through the gear 21 and pinion 26 and the operating shaft 24 maintains the contact arm I8 in open circuit position, until the operator resets the parts manually.

For manual reset, the operator must move handle I3 to the right of Fia. 8 so that lever 55 will release the disc 52 and will permit the parts to rotate 60 and be returned by the operating spring 30 in drum I2 to the closed circuit position, completing the third cycle of release and reset. At the end oi' this cycle, it will be found that the parts are in the position they occupied atthe beginning o! the ilrst cycle, that is to say, with tooth 5Ia of disc 5l in engagement with the "on stop Accordingly it will be seen that the circuit breaker operates to perform two complete cycles of overload release and automatic reset, but that the third cycle will not complete itself automatically, requiring a manual reset. Because of the substitution of a manual reset requirement for an automatic `reset operatifn on the third cycle, the circuit breaker will not continuously go through cycles of release and reset, in the event the overload on the line happens to be a continuous one, as would be the case with the circuit breakers illustrated in application Serial No. 667,149, filed April 21, 1933, above mentioned, these breakers not being provided with a limited cycle means.

Manual reset latch If for any reason the operator desires to latch the circuit breaker in open circuit position to prevent reset in any manner other than manually, he may move handle I5 to the left. This causes the plate 62 to move to the left (Fig. 7) and thrusts the shoulder 66 of this plate into the path of rotation oi' the teeth 6I of disc 60. Whenever the disc 60 is caused to rotate, as for example on an overload release movement of the f parts, or upon a manual control operation, one of the teeth 6I of disc 50 will be engaged and held by the shoulder of the plate 62. This latches all of the parts in open 'circuit position, due to the fact that disc 60 is keyed to the jack shaft 28, and accordingly, is operatively connected to the contact arm I6. I

Return movement of handle I5 to the right unlatches ther parts and permits the automatic reset to take place if the 'parts are in the first two cycles above mentioned, or permits a manual reset to be effected, it the parts happen to be in the third cycle as above mentioned.

It is observed that when the manual reset latch handle I5 is to the left, the parts cannot be reset by the manual reset means I3 et seq. even though they happen to be in the third cycle, because of the fact that the disc 60, if latched by the plate 52, will restrain rotation of the parts, even though disc 52 is released by the manual reset lever 55.

Manual control For manual control operations the handle Il may be moved from left to right and vice versa. When moved to the position of Fig. 9, the lever 'II moves block 42 to the left and moves the thermal element "T with it. 'I'his movement of the thermal element causes movement of the holding plate 38 towards the left and causes the stop 36 to release a tooth of the disc 50, the parts then moving to open circuit position.

Return of handle I4 to the position of Fig. 2 will cause the "oil'" stop 31 of plate 38 to release the disc 50 and the parts will be free to be moved to on position. II they happen to be on the ilrst two cycles, such movement will be automatically eiected; however, if they happen to be on the third cycle, such movement will have to be preceded by a release of the manual reset handle I 3.

Auxiliaries It is at present contemplated to combine with the devices shown in this application and combinations effected through the use of these devices, certain auxiliaries which are not here disclosed but which are disclosed in detail in certain copending applications which are being filed simultaneously herewith.

For example, in application Serial No. 667,149,

cation.

idied* 'api-i121, l1933*, thereare disclosed, in Figs. 1 to lo 11 to 18, two diierent forms of circuit breakers and it is at present contemplated to combine the novel means of this application with either of these forms of breakers, if and as desired. Similarly, it is contemplated to combine thenovel.` means of this application with the multi-pole-unit of Figs. 19 to 28 of that application and-'with thecontrolling breakers .of Figs. 29 to 30 of that application.

Further, in application, Serial No. 667,150, filed April'21, 1933,y there is disclosed an automatically operating -oi holding latch, including an electro-magnet, which operates automatically to hold the contact arm of the circuit breaker in open circuit position once that arm has been moved toppen circuit position by the circuit breaker mechanism, the holding being continued until the overload has been taken oi or cut out of the line. That "oi. holding latch may be added as an appendage to any of the devices chosen in this application or may be utilized to replace certain of the parts shown in this appli- Further, in application, Serial No. 667,151, iled April 21, 1933, there is shown a wind demand latch and indicator, and a spring rewinding device, either or both of which devices may be incorporated in the circuit breaker here shown to function in a manner described in the application just mentioned.

Further, various combinations of the devices here shown and of the devices and features shown in the copendlng applications just referred to, maybeeiected, and it is the present intention to cover in this application as Well as the applications above referred to combinations of the auxiliaries speciilcally shown in those applications with any or all of the devices or` combinations here shown.

Now, having described dierent forms of breakers, reference will be had to the following claims which determine the scope of the invention, it being expressly understood that the breakers heretofore described and disclosed have been chosen merely as examples, and not as illustrating all of the possible embodiments of the inventions.

I claim:

1. In an automatically releasing and resetting circuit protecting device, means for automatically releasing and resetting the device, continuously in cycles, and means automatically energized at the end of a predetermined number of cycles of release and reset for inhibiting the operation of the resetting means, leaving the device ln "released condition, and manually controlled means operable independently of the automatic release and reset means for releasing the inhibiting means and thus .permitting the automatic reset means to reset the device after it has been moved to and left in released condition by an automatic release.

2. In an automatically releasing and resetting circuit protecting breaker, means for automatically eiecting release, means forautomatically effecting reset, the release and reset means operatig in succession so as to release and reset the 'device continuously in cycles, and-means for limiting vthe number of cycles of automatic release and reset, the limiting means, when it opcrates, leaving the devicein a released condition, and manually controlled means operable independent of the automatic means for release md l reset tor releasing the limiting means thus permitting the automatic reset means to reset the device after it has been moved to and left in released condition by an automatic release.

3. In an automatically releasing and resetting circuit protecting device, means for automatically releasing and resetting the device, continuously in cycles, and means automatically energized at the end oi a predetermined number of cycles of release and reset for inhibiting the operation of the resetting means, leaving the device in released condition, and manually controlled means operable independently of the automatic release and reset means for releasing the inhibiting means and thus permitting the automatic reset means to reset the device after it has been moved to and left in 'released condition by an automatic release, and manually controllable means for releasing and resetting the device manually.

4. In an automatically releasing and resetting circuit protecting breaker, means for automatically eiecting release, means for automatically e'ecting reset, the release and reset means operating in succession so as to release and reset the device continuously in cycles, and means for limiting the number of cycles of automatic release and reset, the limiting means, when it operates, leaving the device in a released condition, and manually controlled means operable independent oi the automatic means for release and reset for releasing thelimiting means and thus permitting the automatic reset means to reset the device after it has been moved to and left in released condition by an automatic release, and manually controllable means for releasing and resetting the device manually. l

5. In an automatically releasing andresetting circuit protecting device, automatic means. for releasing and resetting said device in cycles, holding means for automatically maintaining said device in released position after a predetermined number of cycles of operation of the automatic means, and manually controlled means for releasing said holding means and thereby permitting said automatic means to reset the device, said manually controlled means being operable independently of the automatic` means.

6. In an automatically releasing and resetting circuit protecting device, automatic means for releasing and resetting said device alternately, manual means for overcontrolling said automatic means and being capable 'of releasing or resetting said, device or locking it in released position at any time, holding means for holding saiddevice in released position after a predetermined num'- ber of resetand release operations, .and manual means for releasing said holding means and thereby allowing said device to be reset by the automatic means, and being operable independently of the automatic means.

7. In an automatically releasing and resetting circuit protecting device, means for automatically releasing and resetting the device, continuously in cycles, means automatically energized at the end of a predetermined number of cycles of release and reset for inhibiting the. operation of the 'resetting means, leaving the device in released conf dition, manually controlled means operable independently of the automatic release and reset means for releasing the inhibiting means and thus permitting the automatic reset means to reset the device after it has been-moved to and left in released condition by an automatic release, and nually controllable means for releasing and resetting the device manually.

S. In an automatically releasing and resetting circuit breaker, means for automatically eii'ecting release, means for automatically effecting reset, the release and reset means operating in succession so as to release and reset the device continuously in cycles, means for limiting the number of cycles of automatic release and reset, the limiting means, when it operates, leaving the device in a released condition, manually controlled` means 'operable independently of the automatic release and reset means for releasing the limiting means and thus permitting the automatic reset means to reset the device after it has been moved to and left in released condition by an automatic release, and manually controllablemeans for releasing and resetting the device manually.

WILLIAM H. FRANK.

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