US2207960A - Circuit breaker - Google Patents

Description

July 1s, 1940. v WEBER 2,201,960

CIRCUIT BREAKER Filed July 24, 193e 2 Sheets-Sheet l July 16, 1940.

v. WEBER 2,207,960

CIRCUIT BREAKER Filed July 24, 1956 2 Sheets-Sheei 2 83 VCTOR WEBER, nm Jgd/L Patented July 16., 1940 PATENT OFFICE CIRCUIT nimma Victor Weber, St. Louis, Emerson Electric Mfg. corporation of Missouri Application July 24, 19

7 Claims.

The present invention relates generally to circuit breakers, and more particularly to a thermally-actuatable circuit breaker having trip-free reset mechanism.

An object of the present invention is to provide a thermally-actuatable circuit breaker having trip-free reset mechanism.

Another object is to provide a thermallyactuatable circuit breaker which is adapted to be inserted within the casing of a motor, or the like.

Another object is to provide a circuit breaker which is independently either manually or thermally actuatable.

Another object is to provide a circuit breaker which is independently either manually or thermally actuatable. and which includes a heater element in the assemblage for effecting thermal operation.

Another object is to provide a thermallyactuatable circuit breaker which is economical to manufacture, simple in operation, and efficient and eifective in electrical installations.

Other objects andj advantages of the present invention will appear from the following description thereof, taken in conjunction with the accompanying drawings, in which Fig. 1 is a plan View of a preferred embodiment of a. circuit breaker constructed in line with the present invention.

Fig. 2 is a side elevation taken in the direction of the arrow A in Fig. 1.

Fig. 3 is a side elevation taken in the direction of the arrow B in Fig. 1. f

Fig. 4 is a section on the line 4 4 of Fig. 1.

Fig. 5 is a section on the line 5 5 of Fig. 1.

Fig. 6 is a section on the line 5 5 of Fig. 1.

Fig. 7 is a section on the line 1 1 of Fig. 1.

Fig. 8 is a section on the line 8 8 of Fig. 2.

Fig. 9 is a longitudinal section, parts being broken away, showing the relation of the elements at the movement of final setting of the detent and ratchet wheel and before releasing the operating member.

Fig. 10 is a longitudinal section, parts being broken away, showing the relation of the elements when the contacts are separated.

Fig. 11 is a perspective of a link used in the present assemblage.

Fig. 12 is a view in perspective of the reset mechanism or operating member.

Fig. 13 is a view in perspective of the detent showing its position relative to the switch blade when the contacts are closed.

Fig. 14 is a view in perspective of a modified operating member.

Mo., assiguor to The Co., St.' Louis, Mo., a

36, Serial No. 92,363

Referring more particularly to the drawings by reference numerals, 20 indicates generally a preferred embodiment of a circuit breaker constructed in line with the present invention. A plate 2| of non-conductive material serves as a 5 base for the elements of the present device. A support, generally indicated 22, of basically U- shaped configuration, is fixed to the plate 2l by fastening means 23l and 24. The support 22 has an extension 25 projecting from a side of one of the legs of the U, which has a circular opening 26 therein adapted to support a hub 2l. The hub 2l is fixed relative to the extension 25 by means of peening over an end thereof, as at 25. The hub 2l has a reduced portion 29 which supports a ratchet wheel 30 for restricted rotation thereon. A layer of solder 3|' is disposed between the reduced portion 25 and the ratchet wheel 30 to maintain the ratchet wheel fixed in its position until-subjected to heat of a predetermined release temperature. A

A detent, generally designated 34, is pivoted on-a pin 35 in operative relation to the ratchet whee1'3. The pin 35 is supported at 36 in the extension 25, and at 3l in an extension 38 which projects from one side of the other leg of the U-support. The detent 34 includes a rigid bracket 39 having a horizontal portion 44 and a. vertical portion 4U, said latter including a hole 4 l a notch 42 the purpose of which will be subsequently described7 and a projection 43 which extends in parallel relation to the horizontal portion 44. v

The detent 34 further includes a portion generally indicated 45 of resilient phosphor-bronze," or the like, which includes an extension 46 adapted to cooperate with teeth 30 of the ratchet Wheel 30, and a projection 41 having a hole 48 therein. The bracket 39 and the portion 45 are connected together in xed relation at 49 and 50, and are disposed so that the holes 4l and 48 pivotally support the detent upon the aforementioned pin 35.

An operating member, generally indicated 53, is pivoted upon Athe pin 35 adjacent the extension 25 by means of a hole 54 disposed in a main body portion 55 thereof. An extension 56 carries a non-conducting cap 51, which serves as a handle for manually moving the operating member. At the lower portion of the main body 55 is a notch 58, the purpose of which will be subsequently described, an extension 59 of rectangular or square cross-section, which projects normal thereto, and a toe 69. The operating member 53 is stopped in one direction of its pivotal travel by a pin 6|, which is supported in the legs of the U-support by means of the opposed holes 62 and 63, the member 53 abutting the pin 6| at 64 (Fig. 10).

In Fig. 14,'there is shown a modified form of operating member 53, which differs from the one just described only in that the projection 59 is bevelled at 68 for a purpose to be described.

A link, generally indicated 65, and of a conguration shown in Fig. 11, has a hole 66 therein, and includes similar opposed projections 81- having the notches 68. The link 65 is disposed to position the notches 68 in cooperating relation with the notch 42 of the detent 34 and the notch 58 of the operating member 53 (Figs. 9 and 12). The extreme ends of the projections 61 extend beyond the vertically disposed portions of the detent 34 and the operating member 53, and have free movement in elongated slots 10 and 1| I located in the extensions 38 and 25, respectively,

of the U-shaped support. A helical spring 12 has one end connected through the hole 66 and the opposed end through a hole 13 in a vertical extension 14 of the U-shaped support 22. The spring 12 serves to bias the link, and therethrough the detent 34 and operating member 53, toward the left (Fig. 9), the pin 35 serving as a pivot about which this bias is effectuated.

A resilient switch blade 15 is connected to the U-support 22 at 16 by the afore-mentioned fastening means 24, and extends across the bight 32 and in a longitudinal direction with the extensions 25 and 38 of the U-support 22. At the end remote from the connection 16, the switch blade 15 supports a contact 11, and has a projection 18 extending in a plane with the main body thereof. The projection 18 is adapted to cooperate with the projection 59 of the operating member 53, as will be subsequently described. The blade 15 is biased to close the contacts, so that contact is made and held through the inherent resiliency thereof. At the end adjacent the fastening means 24, the blade 15 has wings 19 which abut the legs of the U-support 22 at 19 to assist in fixing the blade relative to a xed contact 8|).

The fixed contact 80 is supported on the plate 2| by means of the element 8| and, as a unit, may be designated a terminal member. A brad 82, or the like, serves to connect the element 8| to the plate 2|, and to provide a terminal to which is connected a lead 83. A projection 85 on the element 8| extends into a hole 36 in the plate 2| to cooperate with the brad 82 in securing the contact 80 in operative position relative to the contact 11. A line lead 84 is connected to the fastening means 24.

A heater element, generally indicated 81, is connected to the plate 2| by the rivets 88 and 89, or the like, which likewise serve as the terminals to which the leads 90 and 9|, respectively, are connected. 'I'he heater element 81 includes a loop portion 32 which extends into the hub 21 into heat-transferring relation with the solder disposed between the reduced portion 29 of the hub and the ratchet wheel 38.

Operation In such specific use, the circuit breaker is disposed within the casing in a position to receive heat generated in the windings thereof. It is so disposed inasmuch as the ratchet wheel 30 is adapted to rotate upon the hub 21 from the solder 3| being subjected to a fusion temperature'reached either from heat given out through the windings of the l motor, or from heat generated by the heater element 81, or a combination of both. The circuit breaker is connected in the main line of the motor by means of the leads 83 and 84 to control the energization thereof. The heater element 89 is connected in some predetermined relation with the windings of the motor by means of the leads 98 and 9|. In one installation, the heater element 89 is connected to the starting or running windings of the motor in such a manner that it is effective only during the starting period thereof. However, it is clear that the heater element may be connected in any wise with the windings of the motor. y

With the circuit breaker in operative position within the casing of the motor, the elements will be in the position as shown in Figs. 2 and 5. When the solder 3| fuses from rise in temperature in the adjacent air, no matter from what source the heat, the ratchet 38 will rotate upon the hub 21 to permit the detent 34 to pivot on ,the pin in a clockwise direction (Fig. 10) due to the action of the helical spring 12 acting through the link 65. In this pivotal movement of the detent 34, the extension 43 moves to the left (Fig. 10) to contact the switch blade 15 at4 43 to raise it in a vertical direction, thereby breaking the connection between the contacts 11 and 80. The circuit breaker is then in a position which, of course, interrupts the supply of current to the motor.

To reset the device after the solder 3| has hardened to fix the ratchet wheel 30 on its hub.

the operating member 53 is pivoted about the pin 35 in a counterclockwise direction (Fig. 9). In this pivotal movement, the toe 69 abuts the extension 43 of the detent 34 at 69 to pivot the detent 34 about the pin 35 in a counterclockwise direction to draw the resilient projection 46 past the teeth 30 of the'ratchet wheel 30 and into a position to be detained thereby. This counterclockwise movement of the operating member 53 and the detent 34 moves the link 85 to the right to place the helical spring 12 in operative tension. After the projection 46 has made cooperative contact wth a tooth 30 of the ratchet wheel 30, the operating member 53 is released. The tension of the helical spring12 through theI link 65 will pivot the operating member 53 clockwise about the pin 35 back to reset position, the link 65 permitting this relative movement between the operating member 53 and the detent 34 due to its free connection in the notches 58 and 42, ren spectively, (Fig. 8).

During the aforesaid reset operation, the contacts 11 and 80 are maintained in a positive open position relative to each other due to the projection 59 of the operating member 53 sliding beneath the projection 18 of the switch blade 15. The projection 59, in the counterclockwise resetting movement of the operating member 53, takes over the function of the extension 43 of the detent 34 to keep the contacts open. Were the cooperating projections 59 and 18 not provided, the contacts 11 and 80 would close during the reset operation, inasmuch as the switch blade 15 is biased, through its inherent resiliency, toward closed position of the contacts.

It is, therefore, apparent that the circuit breaker is trip-free, inasmuch as it is impossible, during the resetting of the device through the operating member 53, to lock the contacts 11 and 80 in closed position. The said contacts do not assume a closed position until after the operating handle has been released and allowed to move to reset position against the pin 6I, the projection 59, during this return movement, sliding from beneath the projection 'I8 and allowing the resiliency of the switch blade 15 to effect closing of the contacts. In should be noted that, when the solder is soft, the contacts 11 and 80 cannot be closed, for only when the detent is retained by the ratchet wheel can contact be eiected. In the embodiment in which the projection 59 of the operating member 53 is of rectangular or square cross-section, after theA handle 51 is re- 15 leased, it cannot be moved to manually open the contacts, for the projection 59 will lock against the projection 18. The projection 59 will slide under the projection 18 only after the switch blade has been elevated by the detent. 20 This construction prevents manual meddling with the switch, and obviates the possibility oi' welding the contacts accidently or otherwise.

In the modification shown in Fig. 14 in which the projection 59 of the operating member 53 is 25 bevelled at 60, the circuit breaker is adapted to be manually opened, for manual counterclockwise movement of the operating-member 53 will raise the switch blade 15 to separate the contacts 11 and 80 no matter what the relative. position of "an the detent 34 may be, for the beveued projection 59 will slide under the projection 18 even in the lowest position of the blade 15. The fact i that the contacts are held closed only through the resiliency of the switch blade 15 permits this 35 independent opening thereof by the operating member 5I.

It is thus clear that there has been provided a thermally-actuatable circuit breaker having a trip-free reset mechanism adapted to fulfill all 4,0, of theobjects and advantages sought to be obtained. In the claims, the use of contacts is intended to include all types of contacting means employed in switches. It is to be understood that the foregoing description and the accompanying 45 drawings have been presented by way of illustration and example, and not as limitation, the invention being limited only by the following claims. v A

What is claimed is:

1. A circuit breaker comprising a base, contacts supported thereon, means to close said contacts, means for breaking said contacts including a detent, thermally-responsive means for releuably holding said detent in inoperative posi- 35 tion, an operating member for moving said detent to releasably held position after. release movable relative to said contacts including a projection adapted to lift one of said contacts from the other contact and to maintain said cono tacts separated during the operation of said member, and means for automatically returning said operating member to inoperative position after reset of the detent by said spring means which pivots the detent in one direction.

65 2. A circuit breaker comprising a base, contacts supportedy thereby, a detent adapted to -open said contacts when closed, fusible means for releasably retaining said detent in inoperative position, and an operating member having a toe .fo adapted to move the detent to releasably retained .position after it hs functioned to open the contacts and having a projection adapted to lift one of said-contacts from the other contact and to maintain the contacts open during the reset operation.

3. A circuit breaker comprising a base, contacts supported thereby, means to close the contacts, means for opening said contacts comprising a detent pivoted for restricted movement and having a projection adapted to move the said contacts apart, spring means for pivoting said detent in one direction, and a manually operatable member for pivoting said detent in the opposite direction, said member being movable relative to the contacts, said member being movable to .noperative position after reset of the detent by said spring means which pivots the detent in one direction, said member also being movable relative to and independently of said detent.

4. A circuit breaker comprising a base, a iixed contact thereon, a U-support, a switch blade connected thereto and having a contact movable relative to and cooperating with said fixed contact, a detent pivoted on the support, a ratchet wheel engageable by said detent, said wheel having fusible means for releasably maintaining said detent in one extreme position of its pivotal movement, an operating member for resetting of the device pivoted on the support and movable relative to the contacts, spring and link means for biasing said detent and said member to one extreme position of their pivotal movements, means on said detent for moving said movable contact from engagement with said fixed contact upon the fusion oi the fusible means, means on said operating member for maintaining said contacts separated during resetting of the device, said last means also serving to effect manual breaking of the contacts through movement of the operating member.

5. A circuit breaker comprising contacts, means for e'ecting engagement of said contacts, means for breaking said contacts including a U-shaped detent and a spring-iniiuenced floating link, thermally-responsive means releasably retaining said last means inoperative, and an operating member movable relative to said contacts.

6. A circuit breaker comprising contacts, means for effecting engagement oi' said contacts, means for breaking said contacts, thermally-responsive means releasably retaining said last means inoperative, an operating member, and means to automatically move said member to operating position after it has been used to reset the device comprising a spring-influenced floating link.

7. A circuit4 breaker comprising a support, a pair of cooperating contacts, means for effecting engagement of said contacts, means for separating said contacts, thermally-responsive means adapted to releasably hold said separating means in an inoperative position, reset means for returning said separating means to releasably retained position after the same has functioned to separate the contacts, and means adapted both to automatically move said separating means into contact separating position upon release thereof by the thermally-responsive means and to automatically move said reset means to its reset position after operation thereof to return said separating means to releasably retained position, said reset means being movable relative to v saidseparating means and to said contacts.

VIC'IDR WEBER.

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