US2090474A - Circuit breaker - Google Patents

Description

Aug. 17, 1937. H. J. cRABBs ET AL CIRCUIT BREAKER Filed Aug. 30, 1954 2 Sheets-Sheet 1 RMI NNE

Filed Aug. 50, 1934 wlTNEssEs; l lNvENToRs 229 Heie/'t J'las and 243 farq. i/g/oom.

`\24/ ATTORNE Patented lAug. 17, 1937 UNITED STATES YPATENT OFFICE -Y Ringbloom,

Turtle Creek, Pa.,

assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation cf Pennsylvania Application August 30, 1934, Serial No. 742,096

12 Claims.

Our invention relates to circuit interrupters and is particularly concerned with electrical switches of the type used for isolating or sectionalizing portions cf a transmission or distribution system.

Switches of this type are generally known as disconnecting switches and have found wide application in present-day transmission and distribution systems, both for the purpose of positively isolating certain equipment or certain portions of a circuit, in order to permit maintenance work to be done thereon, and for the purpose of interconnecting systems which meet at a common point such as a sub-station. Due

' to the large number of these devices which are used on even a small system, it is desirable that they be relatively inexpensive to manufacture.

At the same time, however, the safety of costly equipment and of the individuals working on the line often depends entirely upon the switches, and

it is imperative that they be absolutely safe and reliable in operation.

To further complicate the problem of providing an absolutely safe switch which shall not be unreasonably costly, disconnecting switches are frequently mounted outdoors and are, therefore,

g subjected to extremely adverse weather conditions, particularly in the northern states where ice and sleet formations occur. As a result, a commercially successful device must be extremely rugged and must be positively operable even when frozen or when wet, due to rain or other causes. Further, it is also more or less common practice to mount these switches upon the tops of poles or upon sub-station structures, and it is, therefore, necessary that they shall be operable from one position to the other by a hook-stick or similar device.

The principal object of our invention is to provide an improved disconnecting switch which shall be inexpensive to manufacture, absolutely safe and reliable in operation, and which will be suitable for applications wherein it must be mounted in a more or less inaccessible place.

In the interests of safety, it is imperative that the blade structures of switches of the type under consideration must be securely latched against any movement which might be produced by magnetic stresses or the like when the switch is in the closed-circuit position, and the only satisfactory method so far developed in the art for accomplishing this is to provide a positive. latch which directly engages the blade structure when the switch is in the closed-circuit position. Many 55 of the prior art latching arrangements are cornplicated, unreliable, and unduly costly, and the provision of an improved latching means for disconnecting switches generally is another object of our invention.

A third object of our invention is to provide a disconnecting switch according to the abovementioned principal object which shall be provided with an improved, positive latching means which shall be readily releasable by movement of the operating member during the initial stages of the circuit-opening operation.

A further object of our invention is to provide an improved high-capacity disconnecting switch which shall be provided with a plurality of separate blade assemblages and a plurality of separate latching members, the entire structure being completely operable through vthe movement of a single operating member.

Another further object of our invention is to provide a double-throw disconnecting switch which shall be provided with a separate latching means for holding the blade in either of the two positions of the switch, and with means whereby th-e movement of a single operating memberv will eiiect the release of either of the latches.

An additional further object of our invention is to provide alatching means for an electrical switch which shall be so positioned that it will not be effected by the magnetic reactions set up when current flows through the switch. Y

An ancillary object of our invention is to provide an improved latch for use with disconnecting switches or other equipment which shall be cam-operated.

These and other objects of our invention will be made more apparent in the following description of a preferred embodiment of our invention. Referring to the drawings: ,Y

Figure 1 is an elevational view of a doubletnrow, multiple-blade disconnecting switch wherein are embodied the principal elements of our invention;

Fig. 2 is a plan View of the switch structure shown in Fig. 1;

Fig. 3 is a front elevational view of the operating member used in the switch shown in Figs. 1 and 2;

Fig. 4 is a side elevational View of the member shown in Fig. 3;

Fig 5 is a fragmentary perspective view showing the details of the latch and the switch operating member oi the switch illustrated in Vthe other iigures of the drawings;

Fig. 6 is a fragmentary plan view of a single blade switch which includes the novel latching 'arrangement shown in the device illustrated in Figs. l to 5;

Fig. 7 is a front elevational. View of a modified switch operating member, particularly intended 5 for use with vertically mounted switches of the type illustrated in the other figures of the drawings; and

Fig. 8 is a side elevational view of the member shown in Fig. '7.

l The preferred embodiment of our invention`VV comprises a base member I which may be formed from a channel-shaped section of structural steel, or the like, three spaced insulators which are bolted onto the channelshaped base I by suitable l5 stud bolts 3, a blade assemblage 1, a contact means !I, which includes a pair of spaced conn tact tongues I2, for pivotally supporting the blade assemblage on the central insulatorl 5, and'two sets of spaced contact tongues I3 which are adapted to be engaged by the blade assemblage 1 when the switch is in either of the two closedcircuit positions. Thecontact tongues I3 and the contact` meansY II for pivotally supporting the blade assemblage are bolted to suitable cap members I5, one of which is rigidly aiiixed to the v-upperend"of eachof the three insulators 5. A pair of latch `means I1, each of which is supu ported upon one of the outer insulators 5, is provided for latchingthe blade assemblage 1 in either of the two closed circuit positions.

The blade assemblage 1 comprises two pairs of spaced parallel blade lelements 9, each of which is formed from a flat sheet of conducting material, preferably copper. A suitable circular opening is punched in the righahana @nu (Fig. 2 of each of the separate blade eiementsin order to permit the passage therethrough of the bolts I9 which form the pivotal support `means for the blade assemblage proper. These bolts extend through similar openings vin the upstanding Ytongue portions I2 which serve to support the blade means, and the contact pressure between the inner opposed surfaces of each y, of the two sets of parallel blade elements 9 and the cooper ating supporting tongue i2 is provided by spring washers 2I interposed between the bolt fastenings and the blades.

A second bolt 23 extends through each of the two parallel, blade sections adjacent the unpivoted end of the blade assemblage. These bolts 23, in conjunction with spring washers 25, serve to provide the contact pressure between the blade elements 9 and the cooperating contact tongues I3 which are supported upon the outer insulators. A third bolt 21 extends through each of the two sets of blade Velements 9 adjacent the extreme outer end thereof, these bolts 21 serving as supports for the operating member. 29, which is shown particularly in Figs. v andl.

Two pairs of diverging guide members 3I are bolted upon the cap portion I5 of each of the two outer insulators 5 for aiding in guiding the movement of the switch blade during'the operation of the switch, and the contact tongues I3 are provided with suitable cut-out, portions 33 for'aocommodatingthe bolts 23.

' A circular opening 35 is punched in the outer unpivoted end of each of the blade elements S in order that the blade assemblage may be latched against movement when the switch is in either of the closed circuit positions. While these openingsare shown in Fig. 5 as being formed in all four of the blade elements, this arrangement is followed only because it permits the use of a standard blade element for each of the four sepau rate blade sections, it being necessary to provide the openings 35 only in the two inner blade elements.

Each of the two latching means I1 which cooperates with these openings 35 in the blade elements comprises, as is shown particularly in Fig. 5, a pair of latch members 31, each of which is pivotally supported upon the cap portion i5 of the associated insulator and is biased toward the latched position. by a suitable coil spring 33. Each of the opposed side portions 4I of the operating member 29 is provided with a projecting portion 43 having a cam surface 45 thereon, these portions 43 being adapted to extend into the same openings in the. blade members which are en,- gaged by the latch members 31 when the switch is in the closed circuit position (i. e., the openings 35,). The `dimensions `ci thel openings 35, the latching members 31, and the cam portions 43 of theoperating member 29 are so correlated that the latch members 31 may move freely to the` fully latched position during the circuit-closing operation without interference from the cam portions.

During the initial stages of the circuit-openingV operation, these cam surfaces 45 on the projecting portions 0.13 are adapted to engage cooperating cam surfaces d1 formed on the latch members 31 and to move those members out of engagement with the cooperating openings 35 in. the blade elements 9, thereby effecting the unlatching of the blade assemblage and permitting the switch to be moved to the open circuit position. The movement of each of the latch members 31 toward the latched lposition under the action of the associated biasing springs 39 is limited through `the engagement of a projecting portion [is formed integral therewith and the support therefor. It is necessary to limit the motion of the latch in orderto assure that the switch shall be relatched during every closing operation.

The cap portion I5 of each of the three insulators 5 is provided with a suitable terminal member 5I in order to permit the switch to be readily interconnected into an electrical circuit. j

The switch is shown in one of the two closedcircuit positions in Fig. 1. To open the switch or to move the blade assemblage 1 tothe other closed-circuit position, a hoolesticl; or other degA.

vice is 'insertedintthe operatingreye 53 of the switch operating member A2,9, and that member is v moved in a clockwise direction about its pivot.

point-the bolts21. This movement brings the cooperating cam surfaces `45pavnd I1orthelatch, members 31 and the projecting portions #13 of thew operating member 29r (which portions extend into'.

the openings 35' formed in the bladeelements 9) into engagement with each other, and when'the operating member 29 has been moved so that the projecting cam kportions 4i3 engage the lower.Y side of the'cooperating openings 35 in the blade,

elements 9, the nadjacent latch members 3 1`have member 29.

It should bey notedthat the operatingmember 2S is ireely movable upoirthe bolts 21 which comprise the supporting means therefor, and it. is l'thus 'impossible to rotate the blade assemblage 1 until ,theprojecting cam portions 43 of 'the'Y member 2,9 have been moved adistance suii-` cient to release'the Ylatches 31. .'Ihus, the releasecf the latches 31 takes .place automatically during the initial stages of the opening operation, and it is not possible to rotate the blade assemblage 'l until the latches 3l have been released.

By inspection of Figures l and 5, it Will be seen that the operating member 29 is movable a rather considerable amount with respect to the blade assemblage 'i during each opening operation of the switch, the limits of this independent motion being defined by the engagement of the cam portions 43 with the sides of the circular openings 35. The cam surfaces 45 on the projecting portions i3 engage the cam surfaces tl so that the release of the latches 3l is effected during the initial portion of movement of the operating member 29 independently of the blade assemblage l. rIhis arrrangement permits the latter portion or". this movement to be used for producing a vprying action on the blade assemblage l which serves to start that assemblage in motion and thereby facilitates the opening operation of the breaker. The reaction force of the latch biasing springs 39 is usually sufficient to initiate this prying action, and in addition the heel portionat the lower end of each of the latch members 3l opposite the projection 49 as shown in Fig. 5 rigidly engages the adjacent plate on top of the cap member immediately following the disengaging of the blade assemblage by the latch of which it forms a part. lThese portions thus serve to provide steps for the latches, and the maximum possible prying action necessarily results.

Following the release of the latch members 37, the blade assemblage may be moved either to the open-circuit position or into engagement with the other set of contact tongues i3 supported upon the right-hand insulator. When the blade assemblage 'i is being moved into engagement g) with either of the sets of contact tongues I3, it

is necessary to move the operating member 29 so that the projecting cam portions 43 abut against the upper surfaces (with respect to the base I) of the openings 35 formed in the blade elements 9. This assures that the latch releasing means is in a position Where it in no way interferes with the latching movement of the latch members during the circuit closing operation. Thus, as the blade assemblage is moved. into either of the two closed circuit positions, the latch members 3l automatically engage the blade assemblage, without interference from the latch releasing means. The obvious result, of course, is to provide an absolutely fool-proof structure which may not be operated in an incorrect or undesired manner.A When the blade assemblage is moved to the closed-circuit position, it is positively latched in and the latches cannot be releaseduntil the operating member 29 is moved in the circuit opening direction.

The cam action of the operating member 2d andthe latches 3l is particularly effective in breaking ice which may be formed on the switch during the winter time, and for that reason little i) difficulty will be experienced in operating the switchA under almost any conditions. The outer end of'each of the two sets of parallel blade elements is free to move iaterally on the bolts 21 which serve to support the operating member 29, and the switch is thus made full-oating, which means that the blade elements are capable or" movement toward each other in order to compensate for wear, or the like, during its operation.

Two sets of parallel blades and two latches on each of the spaced conducting members have been shown in the'structure. Itis, ofcourse, a comparatively simple matter t`o utilizejalinost any number of Yblades,since the form of latchY release mechanism which we have disclosedv lends itself readily to amultiple blade construction. It is also possible to utilize only a single blade element, the-latch releasing mechanism being very suitable for this type of switchy as Well. l

Each of the latch members 3'lfis movable ina plane which is-substantially at rightfangles to the normal plane of movement of the blade means. Also, the entire latch structure is disposed outside of the space between the tongues I2 and I3 and, therefore, out of the normal conducting path through the switch. By this arrangement, all magnetic stresses on the latches which might be produced by very heavy overload currents flowing through the switch are entirely obviated andan absolutely safety operation is assured under all possible conditions; If desired, the latch struc-v ture may be insulated from the stationary contact portion, but this is not absolutely necessary, since the right angle disposition of the paths of move-v ment of the latch and the bladeJ obviates any possibility of the latch vbeing opened Vwhen the switch is in operation. n

The structure shown in Fig. 6 is essentially similar to that shown in the other gures of the drawings, except that aA singlepair of parallel blade elements have been utilized. When this is done, it is of course, unnecessary tov utilize a bifurcated operating member. The blade ele"- ments I |19 are essentially similar in form to those shown in the previously described device. The operating member |29 is pivotally supported upon a bolt |21 which extends through both of the' opposed blade elements. The latch |31 engages an opening |35 in the side ,of one of the blade elements and is movable Substantially'Y at right angles to the plane of movement ofthe blade assemblage, and both of the blade elements are full-floating. The construction of the guide horn |3|, and the single bolt I 23 and the two spring washers |25 for securing contactpressure be-V tween the inner surfaces of the blade means and the cooperating contact tongue ||3 are substantially similar to those in the structure already described.

The modied operatingV member 229 shown in Figs. 7 and' 8 is particularly intended'for use with vertically mounted, single vthrow switches. By positioning the eye portion 253 at an angle, ,withv respect to the shank portion 24|, the engagement of the operating member by the hook stick 'or otheruevice is greatly faciiitatedndtne effective leveragev of the operating member is increased.4 This modiedstructure is provided with apro#y jecting portion 243 and a cam surface 245, 'which' correspond to the portions 43and 45 of the mem# ber 29.

In the foregoing we have described the struc-V tural features'and the modevof operation of a novel disconnecting switch which possesses numerous advantages over the structures previously known in the art. Our improved switch utilizes an improved latching arrangement which positively latches theblade against movement when the switch is in the closed circuit position, vbut which is readily releasable bythe initial move` ment of the operating member duringthe circuit opening operation, Qur improved latc'liin'g'fmeans moves in aidirectio'n at rightangles. to'the nor'- mai piane of Vmotion of the biade and thereby assures that the'v magnetic reactions ySet up bythe now of current through the' switch shall not reiec'zt Aany'undesired release of the blade by the latching subjected to a prying action by the movement of the latch releasing means during each opening operation of the switch. Also our improved latch is particularly suitable for use with double-throw switches, the same latch releasing means being adaptable to operate separate latches disposed adjacent either of the two cooperating contacts for the blade means.

While in accordance with the patent statutes we have disclosed the structural features of a preferred embodiment of our invention, it is to be understood that many of the principles disclosed are capable of wide application without departing from the principles of the invention. It is our desire, therefore, that the language of the accompanying claims shall be accorded the broadest reasonable construction and that our invention shall be limited only by what is expressly stated therein and by the prior art.

We claim as our invention:

l. In an electric switch, a pair of spaced conducting members, aV movable blade means for cooperating therewith to open and to close the electricalY circuit through said switch, at least a portion of said blade means having an opening formed therein, an operating member supported on said blade member, and a single latch member having al portion which is adapted to engage said opening when said blade means is in the closedcircuit position, said operating member having a portion which extends into said opening for directly engaging and moving said latch member to eifect the release of said blade means during each opening operation of said switch.

2. In an electric switch, a pair of spaced insulators, a blade means supportedfor swingable movement upon one of said insulators, cooperating contact means supported on the other of said insulators, said blade means comprising a flat plate of conducting material kwhich is provided with a cutout portion adjacent one end thereof, a single, pivoted latch supported on said other insulator and movable to engage said cutout portion when said blade means is in the closed-circuit position, and an operating member which is supported on said blade means adjacent said cutout portion and which is provided with a portion adapted to extend into said cutout portion for directly engaging and-moving said latch to effect the release of said blade means during each opening operation of said switch.

3. In an electric switch, spaced contact'members, a flat blade pivotally supported upon one of -said contact members for swingable movement into and out of engagement with said other contact member, said blade having an opening cut therein adjacent the unsupported end, a single latch member pivotally supported adjacent said other contact member and movable substantially at right angles to the normal plane of movement ofthe blade member to engage the cutout portion and thereby restrain said blade member against movement, means biasing said latch member to the latched position and an operating member supported on said blade, said operating member having a portion extending into said opening which portion is provided with a cam surface for directly engaging a similar cam surface forming a part of said latch member, said cam surfaces being so arranged that said latch member is moved by said operating member so as to release said blade during the initial stages of the switch opening operation.

4. In a double-throw electric switch, a pair of spaced conducting members, a blade means movable into and out of engagement with either of said conducting members for opening and for closing the electrical circuit through said switch, at least aportion of said blade means comprising means having an opening formed therein, an

operating member supported upon said blade member, and a single latch member which is supported adjacent each of said spaced conducting members, each of said latch members being individually adapted to engage said opening when said blade means has been moved into engagement with the adjacent conducting member, said operating member having a portion which extends into said opening for directly engaging and moving the adjacent latch member to effect the release of said blade means during the initial stages of each opening operation of said switch. 5. In an electric switch, a plurality of separate blade members, means for supporting said blade members adjacent one end thereof for swingable movement to open and to close the electrical circuit through said switch, at least some of said blade members having openings cut therein adjacent their unsupported ends, a plurality of separate latch members, each of which is adapted to engage one of said openings when said switch is in the closed-circuit position, and a single operating member supported upon said blade members for simultaneously moving all of those members during the operation of said switch, said operating member having portions which are adapted to extend into said openings in said blade members for directly engaging and moving the adjacent latch member to effect the release of said blade members by said latch members during the initial stages of each switch-opening operation.

- 6. In a double throw switch, a pair of spaced conducting means, a cooperating blade means which comprises a plurality of separate.l blade members, means for supporting said blade members adjacent one end thereof for swingablev movement to open and to close the electrical circuit through said switch, at least some of said blade members having openings cut therein adjacent their unsupported ends, a plurality of separate latch members one of which is adapted to engage one of said openings in said blade members when said blade means has been moved into engagement with either of said spaced conducting means, and a single operating member supported upon said blade members for simultaneously moving all of those members during the operation of said switch, said operating member having portions which are adapted to extend into said openings in said blade members directly engaging and moving the adjacent latch member to effect the release of said blade members by said latch members during the initial stages of each switch-opening operation, regardless of which closed circuit position said blade means is in at the beginning of the switch-opening operation.

'7. In an electric switch, a pair of spaced conducting members, a movable blade member for 'cooperating therewith to open'and to close the electrical circuit through said switch, at least a portion of sain blade member having an opening formed therein, operating member supported upon said blade member so as to be movable a predetermined distance with respect thereto, and a latch means having a portion which is adapted to engage said opening when said blade member is in the open circuit position, said operating member having a portion which extends into said opening for automatically effecting the release of said latch means and for producing a prying action tending to initiate the movement of said blade member toward the open circuit position during each operation of said switch.

8. In an electric switch, a pair of spaced conducting members, a movable blade member cooperating therewith to open and to close the electrical circuit through said switch, said blade member comprising a substantially iiat plate of conducting material which is movable in a plane substantially parallel to the opposed faces thereof, and which is provided with a cutout portion adjacent one end thereof, a latch means having a portion adapted to extend into said cutout portion when said blade is in the closed circuit position, and an operating member which is pivotally supported on said blade member so as to be movable a predetermined distance with respect thereto, and which is provided with a portion which extends into said cutout portion for automatically eiiecting the release of said latch means and for exerting a prying action tending to initiate movement of said blade member toward the open circuit position during each operation of said switch.

9. In an electric switch, spaced contact members, a substantially :dat blade member supported upon one of said contact members for swingable movement into and out of engagement with the other contact member, said blade member havin;Y an opening cut therein adjacent the unsupported end, a latch member supported adjacent said other contact member and movable substantiallv at right angles to the normal plane of movement of said blade member to engage said opening, and an operating member supported on blade so as to be movable a predetermined amount with respect thereto, said operating member having a portion extending into said openin T for engaging said latch member in order to eiiect its release when said operating member is moved relative to said blade member during each opening operation of said switch, said operating member causing said latch member to release said blade member during the initial portion of its possible movement relative to said blade member, and, during the iinal portion of its possible movement with respect to said blade member, exerting a prying action tending to initiate movement of said blade member toward the open circuit position.

l0. In an electric switch, a pair oi spaced conducting members, a substantially flat blade member which is supported for swingable movement in a substantially fixed path, for cooperating therewith to open and to close the electrical circuit through said switch, said blade having an opening cut therein adjacent the unsupported end, a latch member supported adjacent one of said contact members and movable at substantially right angles to the normal plane of movement of the blade'member to engage said cutout portion and thereby restrain said blade member against movement, means biasing said latch member `to the latched position, and an operating member supported upon said blade so as to be vmovable a predetermined amount with respect thereto, said operating member having a portion extending into said opening, which portion is provided with a cam surface for cooperating with a similar cam surface forming a part of said latch member in order that said latch member shall be moved so as to release said blade member when said operating member is moved relative to said blade member during each opening operation of said switch, said operating member causing said latch member to release Said blade member during the initial portion of its possible movement with respect to said blade member, and, during the final portion of its possible movement with respect to said blade member, exerting a prying action tending to initiate movement of said blade member toward the open circuit position.

ll. In a double throw electric switch, a pair of spaced Contact members, a pivotally supported blade which is swingable into and out of engagement with either of said Contact members, said blade having an opening cut therein adjacent the unsupported end, a pivotally supported, spring biased latch positioned adjacent each of said spaced Contact members and movable substantially at right angles to the normal plane of movement of said blade, either of said latch members being adapted to engage said cut-out portion and thereby restrain said blade from movement when that member has been moved into engagement with either of said Contact members, and an operating member supported upon said blade so as to be movable a predetermined amount relative thereto, said operating member having a portion extending into said opening, which portion is provided with a cam surface and is adapted to cooperate with a similar cam surface forming a part of each of said latch members, said opening being of sufficient size that the initial movement of said operating member relative to said blade during each opening operation of said switch effects the release of the adjacent latch member and the final portion of the possible relative movement of said latch member with respect to said blade member produces a prying action tending to initiate movement of said blade member toward the open circuit position.

l2. In an electric switch, a pair of spaced, stationary insulator columns, a Contact supported upon one'oi' said insulator columns, a substantially flat blade pivotally supported upon the other of said insulator columns for swingable movement into and out of engagement with said contact to open and to close the electrical circuit through said switch, said blade having an opening cut therein adjacent the unsupported end, a pivotally supported spring biased latch positioned adjacent said contact member and movable substantially at right angles to the Y normal plane of movement of said blade to engage said cut-cut portion and thereby restrain said blade against movement, and an operating lever pivotally supported intermediate its ends upon said blade and movable a predetermined amount with respect thereto, said operating lever having an outwardly projecting portion, formed integral therewith, which extends into said opening from the side opposite to that which said latch enters, this portion having a cam surface for cooperating with a similar cam surface forming a part of said latch member in order that said latch member shall be moved so as to release said blades when said operating lever is Y moved relative to said blade during each opening operation of said switch, said operating lever effecting the release of said latch during the initial portion of its possible movement with respect to said blade and, during the nal portion of its movement with respect to said blade, exerting a prying action tending to initiate movement of 5 said blade toward the open circuit position.

HERBERT J. CRABBS. CARL A. RINGBLOOM.

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