US2079866A - Automatic interchangeable circuit interrupter or circuit breaker - Google Patents

Description

W. S. MAYER May 11, 1937.

AUTOMATIC INTERCHANGEABLE CIRCUIT INTERRUPTER OR CIRCUIT BREAKER 2 Sheets-Sheet 1 Filed. Sept. 24, 1934 45b 4.4a, V i .5

H6 XI N V EN TOR A TTORNEYS.

May 11, 1937. w 5 MAYER 2,079,866

AUTOMATIC INTERCHANGEABLE CIRCUIT INTERRUPTER OR CIRCUIT BREAKER Filed Sept. 24, 1934 2 Sheets-Sheet 2 Jig/Wam- W INVENTOR.

A TTORNEYS.

Patented May 11, 1937 UNITED STATES AUTOMATIC INTERCHANGEABLE CIRCUIT INTERRUPTER OR CIRCUIT BREAKER Walter s. Mayer, Philadelphia, Pa. Application September 24, 1934, Serial No. 745,232

9 Claims,

A principal object of my invention is to provide a device readily insertable in electric circuits for repeatedly automatically breaking the circuit upon the occurrence of overloads or short circuits, without injury to the device, that has few parts, is inexpensive to manufacture, and which device must be removed from the circuit in order to have access to manually reset the interrupting means, and which does not permit 10 manually interfering with, or holding of, the interrupting means when the device is inserted in the electric circuit.

Other objects of my invention are,--to provide a circuit,interrupter which is fully enclosed by an insulated casing so that the live parts of the mechanism can not be manually touched,that has an automatic delayed time action,-that has electrodes or terminals of the ferrule or knife blade type, or equivalent, rigidly connected to an insulated casing protecting said terminals from manual contact,-'-which may be inserted in standard National Electric Code fuse clips or the like, similar to the commercial fuse,--and .that has combinations of construction which permit the device being made in such sizes that its lengths correspond to the lengths of the N. E. Code fuses, hence thereby being interchangeable with the commercial N. E. Code fuses.

My invention also, consists of certain novel features of construction as will be fully described and pointed out in the detailed description, the drawings, and the appended claims.

Referring to th drawings: Fig. I shows a plan view of my circuit breaker with the cover component of the casing removed. Fig. II is a sectional view taken along the line II--II of Fig. I showing closed position of the circuit breaker.

. Fig. III is a plan view of my breaker with the cover component in place.

Fig. IV is a side elevation of Fig. I but with the cover component in place.

Fig. V is a section taken as in Fig. II except that it shows the open position of the breaker.

Fig. VI is a bottom view of Fig. II. N

Fig. VII is a section taken as in Fig. II but with the cover component removed and with a modifled latching mechanism.

Fig. VIII is a part section taken as in Fig. VII

60 but with another modified latching mechanism.

Fig. IX is a perspective view of the pivoted switching arm, or movable contact structure.

Fig. X is a perspective view of the contact with its insulated blow out magnet secured thereto.

60 Fig. XI is a perspective view of the thermal tripping element, shown in Fig. II, and Fig. III.

Fig. XII is a fragmentary sectional view showing an overload device connected to the circuit controller. L

With more specific reference to the drawings, 5 my automatic interchangeable circuit breaker comprises a box like casing l4, which is preferably of moulded insulation, and which encloses the working parts later on individually referred to. As shown the casing l4, consists of a cover com- 10 ponent l5, and a base component I6, which meet in a rabbetted juncture l1 whereby the two are held in perfect alignment and registry. The cover component I5, is removably secured to the base component l6, by screws l8 which pass thru 16 counterbored openings in its side walls into internally threaded bushings l9 embedded in the base component. See Fig. I and Fig. IV. These counterbores may be filled with compound if it is desired to seal the cover in place. 20

Lodged within external recesses 20, 2|, of the base component It, are metallic tubular terminals 22, 23 capable of engagement with spring clips, such as standard N. E. Code fuse clips. Referring to Fig. IV, a standard 60 ampere fuse 5 clip 23a, is shown secured to the panel or switchboard 33b, andthe tubular terminal 23; is shown engaging the fuse clip 23a. It is quite obvious that knife blade terminals could be substituted, with slight modifications, in place of the tubular 3 terminals.

With provisions above described, my breaker may be readily substituted in place of an ordinary cartridge fuse.

To facilitate application and removal from the 35 spring clips, I have'provided grasp projections 24 on the cover component IS. The grasp projections form a seat for a name plate 25 which is .secured thereto by escutcheon pins 25a.

The cover component is ,provided withopen- 40 ings l5a, through which the position of the switching arm, or movable contact structure, is visible, so that in looking at the device on a plan, view, its condition as to On or Off is readily visible. 45

The words On and Off are marked on the cover as shown. The openings l5a, also serve as are vents.

As a further visual indication of the switching arm, and its position in the casing, the cover component l5 may be made of moulded glass.

The tubular terminal 23, and a V shaped metal contact 26, are electrically connected together and rigidly secured to the base component, by means of the metallic screw 21. The tubular 'idiy secured to the base comw 38 with a washer 23 interl internai recess of the base switching arm, or is located. This switching arm is erspective at Fig. IX as heretofore en.

The swltchii mm, or movable contact struc ture, consists or sheet meta open trough shaped member, having two legs 3;, 32, and a flat cross yoke connectin the legs, which yoke is an integrai of the member and is designated as 33. The eggs 33, are also connected together by the cylindrical hub 34, through which the bearing pin 34a is positioned, and on which the switching arm as a whole, pivots.

The cylindrical hub, 34, has a longitudinal groove 34b, and one edge of which as 340, acting as a stop or catch, engages with a lip 45a of the thermal element 45 to hold the switching arm in the closed position, thus forming a restraining means, and the other edge of which as 34d forms a seat for the looped end 46a of the spring 46. The spring 46, envelops the bearing pin 34a on the outside of the legs 3|, 32 of the switching arm as clearly shown in the several figures. The outer ends of the bearing pin 340. are secured in the base component Hi. In addition to the functions aforestated, the cylindrical hub 34 is slotted as at 34c, so that a screw driver or detachable handle, or equivalent may be inserted to rotate the switching arm as a whole from the off position to the closed position when the device as a whole is removed from the spring clips.

A slot or aperture ISb, in the base component 13, permits a screw driver or equivalent to be inserted into the slot 346 of the switching arm for resetting, but the cylindrical portion of the hub 34, adjacent the slot 15b, practically closes the slot 16b to any attempt to push the screw driver etc., beyond or around the hub and into the body of the base component or into the enclosed mechanism, and said slots are only accessible when the device as a whole is removed from the spring clips, and therefore electric circuit.

The end 452) of the thermal element 45, is rigidly riveted to the fioor portion 22b of the tubular terminal 22, as clearly shown in Fig. II, and thus makes perfect electrical contact therewith. The thermal element45, passes thru an opening 56 in the base 16, which however is screened by the tubular terminal 22. By passing the thermal element thru said opening and into the cylinder portion of terminal 22, I obtain increased length and therefore greater flexibility of the thermal element.

With further reference to the switching arm, a leaf metallic spring 35, U shape in form, is secured to the yoke 33 by a tubular rivet 36, the free end of said spring has a non-arcing conducting block 38 riveted thereto by means of the solid shouldered rivet 39. This rivet passes thru the tubular rivet 36, and the shouldered head of the rivet 39 limits the movement of the conducting block 38 in the direction of the contact 26, as the switching arm moves to off position.

In the closed position shown in Fig. II, it will be noted that the conducting block 38, under action of the spring 35, makes a fiat pressure contact of high electrical conductivity, with the V shaped stationary contact 26. Hence there is no possibility of the surfaces sticking as would be the case if a knife blade contact arrangement were employed.

aovasee The tubular rivet 36, also secures to the yoke 33, the connector 4!, which has coiled portions 42, 42, into which the flexible stranded copper shunt wires 43, 43, are secured. It will be noted that the shunt 43, is looped from the connector M to the connector 450. The loop is to compensate for the movement of the switching arm, and the iunctio' the shunt as a whole, is to conduct the curre n from the thermal element the switching Thus the path or the current thru the device, is from the tubular terminal 22, thru the thermal element 45, thru the shunt 43, thru the leaf spring 35, to the contact block 38, thru the contact 26, thru the screw 21, to the tubular terminal 23, or in the reverse direction.

The spring 46 tends to move the switching arm to the open position from the closed position, and the spring initially assists, but the tendency is restrained from so doing by reason of the lip a of the thermal element, engaging the stop 340 of the switching a-rm hub 34. However when an overload or short circuit, or other abnormal circuit condition occurs, the thermal element deflects, with delayed time action, so that the lip 45a is raised or disengaged from the stop 34c, and thus the switching arm is rapidly moved to the oil position by reason of the action of the aforesaid springs. See Fig. V.

If it is desired to have instantaneous action on a short circuit, and delayed action on an ordinary overload, my device lends itself to incorporating an electromagnet in combination with the thermal element to accomplish the purpose. wherein an electrical bridging member is pivoted at 64. A standard 63 provides one bearing about which trip arm 6| oscillates. The trip arm 3| has a notch or hook therein which receives a cooperative roller, the latter being securely mounted on the oscillatory bridging member, and when the free end of the trip arm is raised, the hook is disengaged from the roller. It is to be noted that a thermal element in normal position does not interfere with the trip 6| but upon carrying an overload the heating of the element causes it to move upwardly thereby tripping the trip GI and releasing the bridging member. An armature 62 of an electromagnet and armature unit is securely attached to the trip SI and upon an overload occurring, the trip GI is raised to release the oscillatory bridging member. The armature 52 may be considered as the instantaneous breaker and the thermal element as the time delay breaker.

As shown in Fig. VI-the words On and 011 are also imprinted on the base component IE to indicate by the position of the screw driver slot 346, or equivalent, as to whether the device is closed or open.

In the modified mechanism shown in Fig. VIII a considerable reduction in the friction to tripping is effected by using a roller 48 with a bearing pin 48a associated therewith on the switching arm, instead of the edge 340 of the hub 34 shown in Fig. IX. The end of the thermal element 4!! as shown in Fig. VIII is modified to engage the roller 48, and also provided with a stop 49a to prevent overtravel.

In the other modified latching mechanism Fig. VII, 9. further reduction in the tripping efl'ort is effected, and furthermore the thermal element 50, is relieved of compression strain. As shown the base component I6 is modified to have bearlng lugs 30a located in the recess 30. A pivot In Fig. XII I show a circuit controller pin 30b passing thru the lugs, has iulcrumed on it a trigger 300 which engages the roller 30d on its coordinating bearing pin 30c attached to the switching arm. A spring 30f controls the trigger pressure and alignment. The thermal element 50 is secured to the cylindrical wall of the tubu iar terminal 22 in Fig. VII at one end, and is looped or spiral in form so as to give increased length and hence greater deflection. As the thermal element 50 deflects due to overload or short circuit, the free end raises the trigger 300 to disengage the roller and allows the switching arm to fly or rapidly move to the open position. It will be noted that the point of pressure of the thermal element on the trigger 300 is over twice the distance from the pivot pin 30b, as is the holding force applied at the roller 30d. Hence the tripping pressure of the thermal element to release the switching arm in Fig. VII is only half as great as that required by the thermal element of the modification shown in Fig. VIII.

The U shaped blow out magnet 26b envelope one leg of the V shaped contact 26 and has a U shaped insulating shield 26a interposed so that any are, between 38 and 26 will not flash on the sides of the magnet 26b. The object of the blow out is to facilitate the extinguishing and ruptur ing of the arc, incident upon 38 moving out of circuit with 26. r

Further-in connection with the modification shown in Fig. VII, it will be noted that in place of a' screw driver slot in the hub of the switching arm for moving said arm to closed position, I have substituted a finger piece i so that the device-may be closed with the finger or equivalent. I

The side barriers Ila and 22a of the recesses 2i and 20 prevent the device from being inserted sidewise into the spring clips, which would ex- .pose the slot or aperture l6b of the base component i6, and incidently the manual operating end of the switching arm as the slot 346. The aforesaid barriers, also partly cover and thus prevent manual contact with the -fuse or spring clips as 23a. See Fig. IV.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination of a circuit controller of the switch type and a separable actuator for said circuit controller, said circuit controller comprising a housing, a movable electrical bridging member within said housing, means to hold said movable bridging member in closed circuit position, means to move said bridging member into open circuit position upon the occurrence of predetermined circuit conditions, and an aperture in said housing through which a detachable actuator may be inserted to move the bridging member, said aperture being accessible only when said controller is removed from the circuit.

2. The combination of a plurality of stationary spaced terminals of a circuit, and a circuit contrailer of the switch type, said circuit controller comprising a casing, a plurality of spaced external terminals rigidly secured to the casing and being adapted to engage said stationary terminals, movable circuit controlling mechanism within said casing, means for resetting said mechanism within said casing from open to closed circuit position, an aperture in the casing through which the resetting means may be actuated. said aperture being located between said stationary spaced terminals and being accessible only when the device is removed from the stationary terminals.

3. A circuit breaker comprising a pivoted con tact member having a forked arm thereon, means to retain said pivoted contact member in closed circuit position, an enclosing casing for said circuit breaker, and an aperture in the casing through which a removable contact member actu ator may be inserted for engaging the forked member so as to rotate the contact member about its pivot, but which aperture is only accessible when the breaker is removed from the circuit.

4. The combination of a plurality of vertically aligned spring clips and a circuit breaker, said circuit breaker comprising a movable contact, means to hold said contact in a predetermined position, means to reset said movable contact, an enclosing casing, spaced, external terminals rigidly fastened to said casing in substantially vertical alignment and being adapted to engage said spring clips, said movable contact pivctally mounted in a recess in said casing alignment with said terminals, means for electricaliy conducting current iromsaid terminals to said movable contact, said casing having an aperture therein through which the movable contact may be reset, barriers on the casing for restraining the position in which the casing may be inserted in the spring clips whereby the aperture is inaccessible when the casing is inserted in the spring clips, and means electrically operative for actuating the restraining means from closed circuit position to open circuit position.

5. A circuit breaker comprising a casing, a fixed terminal and a movable contact adapted to engage said terminal located within said casing,

a plurality of spaced external terminals rigidly secured to said casing, one of said terminals being connected to the movable contact and the other terminal being connected to the fixed terminal, means to move' said movable contact, means to restrain said movable contact in closed circuit position, and said casing having an aperture through which the movable contact may be reset, saidaperture being located in said casing whereby'the aperture is inaccessible when the breaker is connected in operative position.

6. The combination of a removable circuit breaker and a casing having a chamber therein, said casinghaving an external aperture which leads to the said chamber, a fixed main terminal and a pivotally mounted movable bridging member within said chamber, a plurality of externally mounted terminals on said casing, one of said terminals being connected to the movable bridging member and the other of which is connected to the fixed terminal, means to hold the said movable bridging member in closed circuit position, means to move said movable bridging member into open circuit position upon the occurrence of predetermined circuit conditions, a

forked member on said movable bridging arm ad- Jacent to said aperture whereby the movable contact arm may be reset, said aperture being located in an inaccessible position when the breaker is connected in an electric circuit, and means to indicate whether the bridging member is in open or closed circuit position.

7. In a circuit breaker, a housing enclosing said circuit breaker, a movable contact member and a. stationary contact member within saidhousing, a thermal element, a roller mounted upon the movable contact member, a trigger pivotally mounted within the chamber of said movable contact member, said trigger including a latch whereby the roller will interiit with said latch when the contact member is in closed circuit position, and said thermal strip being adapted to engage said pivotally mounted trigger to disengage said trigger from said roller upon the occurrence of predetermined circuit conditions, thereby releasing the contact member, and means on said movable contact member to close the circuit, said means being accessible only when the circuit breaker is removed from the circuit.

8. A circuit controller 0! the quick-break switch comprising a fixed terminal, a quickbreal: movable electrical bridging member adapted to engage said fixed contact terminal to complete the circuit, an enclosing insulating casing for said fixed terminal and said bridging member, said casing having an opening therein, said bridging member pivotally mounted adjacent said opening, a detachable member for actuating said bridging member, means on said detachable member and said bridging member, said means comprising an interiitting lug and recess, and said casing opening being accessible only when the breaker is removed from the circuit.

9. A circuit breaker of the quick-break type comprising a housing having a small aperture therein, a plurality of fixed terminals, an oscillatory electrical bridging member adapted to be connected to or disconnected from said fixed terminals, means adapted to rapidly move said bridging member from closed circuit to open circuit position, and an extension whereby said bridging member may be actuated from open to closed circuit position on said bridging member located adjacent said small aperture, said extension being accessible only when said circuit breaker is removed from the circuit.

WALTER, S. MAYER

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