US2024216A - Circuit breaker - Google Patents

Description

Dec. 17, 1935.

S. S. GRADY CIRCUIT BREAKER Filed April 30, 1951 n 2/ 29 l f4 3.5 30

lNvr-yo;` BY D f @may y Patented vDec. 17, 1935 UNITED STATES CIRCUIT BREAKER Stephen S. Grady,

Magnolia, N. C., assigner to Fusoid Electric Co., Inc., a corporation of New York Application April 30, 1931, Serial No. 533,949

11 Claims.

This invention relates to circuit breakers and with regard to its more specific features to such devices adapted for the protection of electric circuits against excessive currents.

One of the objects of the invention is to provide a device of the above nature practical and ecient and capable of meeting the requirements of use in a highly satisfactory manner. Another object is to provide a device of the above nature simple in construction and at al1 times dependable inaction. Another object is to provide a mechanical circuit breaker adapted to take the place of cartridge fuses and co-act in an ecient manner with the standard mountings provided ltherefor. Another object is to provide such a device conveniently adjustable to the varying conditions of practical use. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements,

and arrangements of parts as will be exemplified in the structure to be hereinafter .described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which are l are shown one or more various possible embodlments of the several features of this invention.

Figure 1 is a side elevation of a circuit breaker, parts being cut away to better disclose the structure.

Fig. 2 is an end view hand end of Figure 1.

Fig. 3 is a view similar to Fig. 2 .showing a slightly modified form, and

Fig. 4 is a sectional view of another modification.

Similar reference characters refer to similar parts throughout the several views of the drawing.

Referring now to the drawing, in detail, there is shown in Figure ila pair of metallic members shaped to provide parts and respectively of rounded contour 'as shown in the end view of Figure 2. The part I0, as shown in this gure, terminates in lateral anged portions I2 and I3 and a pair ofup-standing ears I4, the `part Il being shaped in a similar manner and providing a similar pair of ears I5. These parts are formed of a suitable conductingV metal and are rigidly connected together by a member IB of insulating material which is secured to the flanged portions I2 and I3 of the part I0 and to 'corresponding flanged portions of the part II. These rounded parts I0 and I I are so shaped and are so spaced by the member I6 as to t into and co-act with the standard cut-outs or fuse clips which are made to receive cartridge fuses of standard design and size. The spring clips of such a standardfuse mounting are represented at II and i3 looking toward the leftwith the members I0 -and I| respectively coating therewith in operative position. lIt may be here noted that the usual cartridge fuse mountings are made according to different standard designs for cartridge fuses of different current capacities and that such mountings will be hereinafter l referred to generally as standard fuse mountings.

It will be seen that the parts I0 and II are conveniently slipped into place in the clips I1 and I8, in place of the usual rounded end portions of the ordinary cartridge fuse.

Opposite the member I6 is a member I9 of insulating material to which is. secured, opposite the ears I4, a member 20 provided with a pair of depending ears 2|. The ears 2| are adapted to co-act with the ears I4 as shown inFgure 2 and make electrical connection therewith. Ad'- jacent the other-end of the member I9 is secured a member 22 similar to the member 20 and provided with a pair of depending ears 23. The ears 23 make electrical contact with the ears I5 of the part and are pivoted thereto as by a pin 24. `The member I9 therefore and the parts connected therewith are capable of swinging about the pin 24, the ears 2| thereby moving into or out of electrical contact with the ears I4.

. Carried bythe member I9 is a solenoid winding 25 connected by conductors 26 and 21 with the ears 2| and 23 respectively. Therefore when' the member I 9 with its connected parts is swung downwardly as viewed in Figure 1 so4 that the parts 2| and I4 are in contact, the circuit is complete from the fuse clip I1 through the solenoid 25 to the fuse clip I8, and when the member I9 is swung to the position shown in Figure 1 the circuit in broken.

A flat spring 28 urges the member I9 and the parts carried thereby to swing outwardly to the position shown in Figure 1. Overhanging the left-hand end of the member I9 is a latch member 29 adapted to co-,act with a latch member 3|) to hold the parts in the position shown in Figure 2 against the action of the spring 28. The latch member 3D is suitably secured to lthe vmembers I6 and I0, for example, as at 3| and 32. The latch member 29 terminates at its upper end in a rounded portion 29a resting upon the upper surface of the member I9 and through an enlarged opening in which passes a screw 33 thread ed into the member I9. Between the head ofthe screw 33 and in part 29Il is a compression spring 34. The spring 34 thus tends to hold ythe'latch member 29 in the position shown in the drawing. but upon movement of the lower part of the member 29 outwardly to disengage the latch member 3D the part 29a rocks upon the surface of the member I9. Passing through the center of the solenoid 25 is a rod 35 preferably of brass or other suitablel non-magnetic substance which .is vsupported at one end by a bracket 36 secured to the member I9, and at the other end by the latch member 29 through which it passes. The

l rod as is provided with a 'shouider 31 which limits acts in opposition to the pull of the solenoid upon the part 39 and the rod 3 5. 'I'he movement of th rod to the left therefore, under the urge of the solenoid 25 or otherwise, through the shoulder 38, will release the latch member 29 from engagement with the catch 30, thus permitting the spring 28 to swing the parts to the position shown in Figure 1, thus breaking the circuit.

Considering now the action of the apparatusL when the parts are in position of engagement as shown in Figure A2, current will flow between the fuse clips |1 and I8 through the solenoid 25. 'I'he parts are so proportioned that when the current flowing exceeds a predetermined value the pull of `the solenoid 25 is sufficient to draw the part 39 inwardly against the action of the springl 4|. 'I'he predetermined current at which this action takes place may be regulated or adjusted "i by adjustment of the compression in the spring these knife-like blades.

4|. Such movement of the part 39 through the rod 35 moves the latch member 29 irom engagement with the catch 30 and the spring 281s free to swing the parts out of engagement to the position shown in Figure 1. The ears 2| and |4 therefore being out of engagement, the circuit is broken. Thus the circuit is automatically protected from the danger of excessive flow of current and the value of the current at which thede'- vice will trip may be adjusted. In order to insure further protection, if desired, a fuse 42 may be inserted in series with the solenoid, the fuse 42 being adapted to blow at a 'slightly higher current vthan that at which the solenoid ls set to move the rod 35.

The'circuit breaker may be operated manually at any time if so desired, substantially taking the place of an extra switch. The circuit may be broken manually byy simply pushing the rod 35 tothe left by a thrust on its ,projecting righthand end, or the part 29a of the latch may be rocked to release the catch. Inorder to reset the circuit breaker, `it is necessary to simply push the member |9 inwardly until the latch is again in engagement. I'he circuit breaker may thus be operated manually for either making or breaking the circuit in a highly convenient manner without removing the device or in any way interfering with its mounting 119011 the fuse clips |1 and |8. Furthermore, the *position of the parts at all times clearly indicates whether the circuit is complete or breken.

'I'he larger sizes of standard make cartridge fuses are made with knife-blade contacts instead .f of the rounded contacts and the standard mountings vor fuse clips are accordingly made to receive *n ing of this type is represented at 43 in Figure 3.

In order to co-act with this mounting the device above described in connection with Figures 1 and f 2 is provided with knife-blade contacts 45 instead ;of the rounded contact members I0 and As is shown in Figure 3 the member forming the contact ears |4 is provided with a lateral portion-44 from the opposite side of which projects l standard fuse mountf the knife-blade 45. It is tobe understood of course that, in this instance, the member forming the ears |5 at the otherfend of the device, is

insulating plug 46 about which is a threaded me- 15 tallic sleeve 41 adapted to iit the threads of -a standard plug fuse mounting. At the end of the member 4 6 is a contact 48 serving as the other contact to make connection with the socket. The plug member 46 is,hollow and mounted 20 therein is a solenoid 49 connected as will presently be described.

The ,plug Imember 46 is joined to an annular member 50 also of insulating material. Secured to this member 50, as at 5| and 52, is a pair of 2 oppositely disposed metallic members 53 and 54 respectively. These members 53 and 54 are of a suitable conducting metal of resilient properties, vand projecting upwardly to the interior of the annular member 50, they tend to spring in- 30 .wardly toward each other. Between these two contact springs 53 and 54 is gripped a member 55 of insulating material normally projecting from the interior of the annular member 5|) as shown. This memberv 55 is provided with an 35 yannular groove in which rests an annular conducting strip 56. The spring contacts 53 and 54 are provided with inwardly directed projections 53a and 54a respectively which normally extend into the annular groove in the member 40 55 making contact with the conducting strip 56 therein. The strip 56 therefore normally makes electrical connection between the spring contacts 53 and 54 and the spring contacts serve to yieldingly hold the member 55 in the position shown l5 in the drawing.

Passing through the `member 55 and threaded therein is a, rod 51 preferably formed of brass or other suitable non-magnetic substance which extends downwardly through the solenoid 49 and 50 is provided at its lower end with a member 58 of iron. Themember 58 therefore is adapted to be drawn inwardly by the solenoid 49 thus carrying thel rod 51 and the member 55 upwardly against the action of the spring contacts 53 and 55 54. The solenoid 49 is connected at one end to the contact member 48 as by a conductor 59 and at the other end to the spring contact 53 as by a conductor 60. The other, spring contact 54 is connected as by a conductor 6| with the contact 60 sleeve 41.

With the parts in normal operative position, as shown in the drawing, the circuit is thus completed from the contact member 48 through the solenoid 49 to the contact sleeve 41. In the action o5 foi' the device when the current through the solewith a screw head 62 positioned in' a recess in the top of the member 55 so that the rod 51 may be conveniently threaded in or out of the member 55 thus changing the normal position of the iron member 58 with respect to the solenoid. In this manner the value of the current at which the solenoid will draw the member 5B upwardly against the action of the springs 53 and 5l may be conveniently adjusted. The lcircuit is thus automatically protected against currents in excess of a predetermined value.

After the device has been tripped as above described, it is conveniently1 reset without removing the same from the fuse mounting by 'simply' pushing the member 55 back into place; Furthermore, the device may be operated manually at any time to break the circuit, it being necessary to simply grasp the projecting member 55 and draw it outwardly. The position of the part 55 indicates at all times `whether or not the mechanism is in circuit closing position.

From the above it will be seen that there is herein provided apparatus which embodies the several features of this invention and attains the objects thereof and that the apparatus is well adapted to meet the requirements of practical use. The mechanisms are simple in construction, at all times dependable in action and attain many practical and useful advantages.

It will also appear that by means of the present invention, see the embodiment illustrated in Fig. l, when the device is used with a circuit of alternating current that when an over-load occurs so that the current in the solenoid winding 25 attracts the core 39, the inductive reactance thereby established will automatically break the current even though the latch member 29 did not clear the latch member 30 and the spring 28 thereupon did not raise the bracket I9 to cause the contact between the contacts 2| and Il to be broken.

In otherwords, the induction produced in the solenoid winding 25 not only initiates the mechanical interruption of the circuit by actuation of the plunger 35 in turn to actuate the latch member 29y to permit the spring 2B to raise the bracket I9 but in addition thereto also electrically interrupts the current due to the inductive reactance set up when the core 39 is moved into lthe winding 25.

It will also appear that, by means of this device, due to the fact that the current may be electrically interrupted by the inductive reactance produced when the solenoid winding 25 attracts the core 39, the subsequent separation of the contact 2| from the contact i4 will occur when the current has already been broken so that arcing between the contacts 2| and Il will be eliminated, if the current is so interrupted by the inductive reluctance before the plunger 35 has had an opportunity to free the latch member 30 from the latch member 29 by co-operation with the spring 28.

As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinabove set forth is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the class described, in combination, a pair of members removably coacting with a pair of standard fuse clips and each having exterior of said clips a lateral flange portion extending over the outer edge of said clips, a

rigid base member of insulating material secured upon said Iiange portions and positioned thereon exterior of the outer edges of said clips, connecting said members together and holding the same in xed relation to coact with said fuse clips, a mechanically operated switch connecting said two members, and means adaptedto open said switch upon current of predetermined value flowing therethrough, said switch being adapted for manual closing with said members remaining in operative positionin said fuse clips.

2. In apparatus of the ,class described, in combination, a member yadapted to coact with one of a pair of standard fuse clips, formed of sheet metal and having a part adapted to enter said fuse clips and a pair of upstanding ears projecting outwardly therefrom, a second member adapted to coact with the other of said'pair of fuse clips, a switch member'electrically connected with said second member and having a part adapted to slide into position between and bear outwardly against said pair of ears and to move into and out of engagement therewith to make and break electrical connection between said two members, and means adapted to move said part of said switch mechanism out of engagement with said upstanding ears upon current of predetermined value flowing therethrough.

3. In apparatus of the class described, in combination, a rigid base member of insulating materialy a pair of members mounted thereon and adapted respectively to coact with a pair of standard fuse clips, a pair of upstanding ears elecIrica-lly connected with one of said members, a second pair of upstanding ears electrically connested with the other of said members, a switch member having one end pivoted upon one of said pair of ears by a pivot pin passing through said ears and adapted to swing thereon and having a part adjacent the other end thereof adapted to slide into and out of position between and in engagement with the other of said pairs of ears to make and break electrical connection between said pair of members coacting with said fuse clips, and means adapted to open said switgh upon current of predetermined value flowing therethrough.

4. In apparatus of the class described, in combination, a rigid base member of insulating material, a pair of contact members mounted upon said base member and adapted respectively to coact with a pair of standard fuse clips, an upstanding metal part adjacent one end of said base member electrically connected with one of said contact members, a second`upstanding metal part adjacent the other end of said base member and electrically connected with the other of said contact members, an arm of insulating material having adjacent each end thereof a projecting metal part adapted respectively to engage said two upstanding metal parts on said base member and make electrical connection therewith, conducting means between said two projecting metal parts of said insulating arm, means pivotally vconnecting one of said projecting metal parts to said upstanding part on said base member with which it engages, and means adapted upon current of predetermined value flowing through said conducting means to swing said arm about its pivot and move said other projecting metal part thereon out of engagement with its corresponding upstanding metal part on said base member.

5. In apparatus of the class described, in combination, a rigid base member of insulating material, a pair of members thereon adapted respectively to coact with a pair of standard fuse clips, a switch interposed between said two memopposition to said electro-magnetic means, said adjusting means being accessible andoperative with said pair of members in operative position in said fuse clips.

6. In a circuit breaker for an electric circuit of alternating current, the combination with two terminals in the main line of the circuit, of a bracket pivotally connected to one of said terminals, a xed latch member secured to the other terminal, a movable latch member at the end of said bracket, a solenoid winding mounted on said bracket and electrically connected in the main line of the circuit and to` said terminals when said, latch members are in locking engagement, a spring urging said bracket into latch breaking position.' a non-magnetic plunger mounted on said bracket to actuate the latch member on said bracket; and a soft iron core on said plunger normally disposed outside of said winding to be attracted by the winding when an overload occurs to build inductive reactance to break the current electrically and to cause saidplunger toI actuate said movable latch member to permit said spring to actuate said bracket to interrupt the current.

7. In a circuit breaker for an electric circuit ofalternating current, the combination with vtwo terminals in the main line of the circuit, of a bracket pivotally connected to one of said terminals, a iixed latch member secured to the other terminal, a movable latch member at the end of' said bracket, a solenoid winding mounted on said bracket and electrically connecting said terminals in the main line of the circuit when said latch members are in locking engagement,-a spring urging said bracket into latch breaking position, a non-magnetic plunger mounted on said bracket to actuate the latch member on said bracket; and a soft iron core on said plunger normally disposed outside of said winding to be attracted b y the winding when an overload occurs to build inductive reactance to interrupt the current electrically and to actuate said plunger in turn to actuate the latch member on said bracket to permit said spring to actuate said bracket'out'of engagement with said other terminal.

8. In a circuit breaker for an electric circuit A of alternating current, the combination with two terminals in the main line of the circuit; of a frame 'pivotally connected to one of said terminals; a iixed latch member secured to the other terminal; a movable latch member at the free end of said frame adapted .to cooperate withsaid fixed latch member to anchor said frame in circuit making position; a spring urging said frame into latch breaking position; and means for actuating said vmovable breaking position when an overload occurs consisting in a solenoid winding electrically connected to one of said terminals, a plunger slidably mounted in said solenoid, and a soft iron core on said plunger normally disposed outside of said of said terminals .ce ss; a spring finger connected to each latch member into latch on said frame; resilient means for anchoring said frame in position to bridge said two terminals by said electrical conducto and means for moving said frame into position to interrupt the current across said conductor when an overload occurs including a solenoid winding electrically connected to `one of said terminals in the :nain line, a plunger mounted on said frame and slidable in said solenoid winding, and a soft iron core on said plunger normally disposed outside of said winding to be attracted by the winding when an over- -load occurs `to build inductive reactance to interrupt the current electrically and to cause said plunger to overcome the resilient connection between said resilient means and said frame and thereby to release said frame into circuit breaking position.

l0. In a circuit breaker for an electric circuitr of alternating current, the combination with two terminals in the main line of the circuit; of, a movable frame; a conductor mounted on said movable frame; a spring finger connected to each and positioned to engage osaid conductor and anchor said frame in circuit making position; and means for actuating said frame into iingerireleasing position and thereby circuit breaking position consisting in a solenoid Winding connected to one terminal in the main line, a plunger mounted onv said movable fr me and slidable in said Winding, and a soft iron core on said plunger normally disposed outside ofl said winding to be attracted by the .winding when an of alternating current, the combination with two terminals in the main line of the circuit; of a movable frame consistinglof a tapered plug composed of insulating material and having an annular recess; an electricalconductor in said rea of said terminals and positioned to enter said recess resiliently to anchor said plug and to contact said conductor in circuit making position; and means for actuating said .frame into finger releasing position and thereby circuit breaking position conv -sisting in a solenoid winding connected to one` terminal in the main line, a plunger mounted on said movable frame and slidable in said winding, and a soit iron core on said plunger normally disposed outside of said winding to `be attracted by the winding when an overload occurs to build inductive reactance to break the current electrically and to actuate saidframe out of engagement of its conductor by said spring fingers and thereby into circuit breaking position. "I

STEPHEN s GRApY. 'i

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