US836994A - Interlock for electric switches. - Google Patents

Description

PATENTED'NOV. 27', 190@ O. 0. RIDER. INTERLOCK EURv ELECTRIC SWITGHES.-

APPLICATION FILED SEPT. 28, 1905.

2 SHEETS-SHEET L v/rn/er'fof" 0/'0/7 0. /der' @www A Aug IJATENTED NOV. 27, 1906.

O. O. RIDER.

INTERLOCK POR ELECTRIC SWITCHES.

APPLICATION FILED SEPT. 28, 1905.

SHEETS-SHEET 2.

Fig.

/n//eNa/ ifa/7 der UNltTED ORAN O. RIDER., SCHENEQTADY,

narran-ir raten.

NEV YORK, ASSIGNOR TO GENERAL UNTEVLOCK FOR ELECTRlC SWETCHES.

nu. seesee.

l Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed September 28.1905. Serial Noy 280.490.

Be it known that 1, OaAu O. linnen, a citizen of the United States, residing at Schenectady, county oi Schenectady, State ol New ork, have invented certain new and useful Improvements in lnterlocks' for lillectric Switches, of which the folhiwing is a speciiication.

The present invention relates to electric switches, and more particularly to iiiterlocliing means whiel'i will permit their operation only in a definite manner.

In many electrical systen'is it is absolutely necessary inorder to insure sal'ety to the operation of the system that the switches employed therein he operated in a particular way. o

The present invention consists in interlocking i'nechanisn'i ol' this sort which when used with a plurality ol' switches requires their operation not only in a definite order, but the restoration ol' the switch last operated to its former position hel'ore operating the next.

The invention is particularly applicable to switches employed in starting and running induction-iiiotors fand although capable. of

other uses will bedcscribed in that connection.

Referring to the accompanying drawings, in which two forms of' the invention are disclosed, Figure l a partial sectional elevation oi" an oil-switch to which interlocking.

mechanism constructed in accordance with the present invention is applied, the section being taken on a plane indicated by the line l l of Fig. 2. Fig. 2 is a plan View of the same, Fig. 3, a detail illustrating the automatic trip mechanism. Figs. 4, 5, (i, and 7 illustrate different Views ol the interlocking mechanism, Fig. 8 is a dotailedvicw `illustrating the arrangement of the switch-con- A tacts. Fig. 9 is a View oll a modified form ol' the invention, and Fig. electric connections.

Throughout the views like characters refer to like parts.

The switch to which I have shown my invention applied is a three-phase oil-switch ol a Well-known type and comprises a plurality of fixed contacts l0, projecting downwardly from a horizontal supporting-frame ll, suitably secured to a switchboard or other support 12. The contacts 1U are surrounded by l() is a diagram ot an oil-can 13, provided with a suitable insulating-lining 14 and iartitions 15voetween the contacts of the diiierent phases. Coperati-ng with these fixed contacts are the bridging-contacts 16, carried at the lower ends of reciprocating rods 17, which are secured at their upper ends to a yoke 1 S, directly connected to the operating mechanism of .the switch. T he contacts 1() are provided at their upper ends with suitable terminals 20 and are maintained out of electrical engagement with the supporting` member 1l by porcelain insulators 2l in a welleknown manner. lilach set ol' liridging-contacts 16 is operated by an independent secured to a plate 23, carried on the front of the switchboard l2. The movements oil the operaiing-levers 22 are cfmmiuiiicated to the yokes 1S and thence to the l)ridging-coiitacts by means of a system ol' links and levers. This system cmnprisos a lever 2li, pivotally secured at its opposite ends to'thc yoke 18, and the vertical portion ol the l'rame 1l. This lever is rocked about itsiixcd pivotal `point so as to reciprocate the yoke 18 and movable contacts oi' the switch by means of a toggle consisting of the links 25 26, acting between said lever and a lixed point 27 on the supportingfframe 11. The toggle is collapsed and extended through the agency of the link 28, which is connected at its outer end to the lever 22. l

The mechanism thusfar described constitutes practically two independent operable switches, which in the starting and ruiming of an induction-motor arc'intended to be opcratcd successively and so that at any time only one switch will be closed. ll. one ol' these switches, which may -bo designated A, be considered as the starting-switch, and the other, which may be designated l, thi` running switch, the switch A will irst be thrown tor has speeded up somewhat the switch A Will be opened and th(` switch l sin'iultaneously closed, so as to disconiiect -the motor l'r'om the conlpensator and connect it directly to the line. 'l`his simultanmius movement of the switches is brought about by the operator holding one switch-haver in each. hand and simultan,eously'throwing one lever in and the other ouit. This operation will be clearly apparent, l'rom Fig. 10, where 2t), 3U, and 3l ilesigrate the three legs of a tlneewhen starting the motor, and when the mo-l operating -lever `22, pivotall v phase supply-circuit for the induction-motor 32. The closing of the starting-switch A connects the motor- leads 33, 34, and 35 and the leads 36, 37, and 38, running to the compensator 39, which is directly connected,through a disconnecting-switch S, to the three legs of the line at the points 40, 41, and 42. When the ruiming-switch B is closed, the leads 33, 34, and 35 of the motor are connected to the leads 43, 44, and 45, respectively, which are directly connected to thc three legs of the line through the trip-coils, which open the switch from its running position. In such a system it is necessary that the circuit through the compensator be broken by opening the switch A before the switch B is closed to establish direct connection with the line, since the reactive coil of the compensator would burn out or in any event waste energy. This object is obtained by the use of the interlocking mechanism constituting the subject of the present invention. This interlocking mechanism is preferably located on the upper side of the supporting-frame 11 of the switch in a position to obstruct the movement of certain parts of the operating mechanism. According to one form of the in vention a lever 45 is centrally pivoted at the point 46 to the upper side of the frame 1l midway between the actuating-toggles of the two switches. The outer ends of thc lever 45 are adapted to engage the rear faces of tbe 'links 26 of the toggles, thus serving as sto-ps, and the pivot 46 is so positioned that the outer ends of the lever will prevent both of the togglcs being extended at the saine time. A[n other words, this lever will prevent the closing of both switches at the same time. In the operation of the mechanism this necessitates the opening of the switch A before it,is possible to close the switch B. Now in order to insure the operation of the switch A before the operation of the switch B, l employ a vertically-movable latch 4T, pivotcd at the point 4S to aportion ot' the supporting-frame 1i and provided with a tail 49 at its outer end, which may be enga ged by a lever 50, carried by the pivot 46 and projecting into the path of movement of the togglelink 26 of the vswitch A, The lever 5() is drawn at all times against the link Z6 of the switch A by a spring 5l, while the opposite end of the lever 45 is drawn similarly against the corresponding toggle-link of the switch B by the spring 52, these springs being connected, respectively, between the said levers and fixed points on the frame l l. The latch 47 through the agency of a shoulder 53 which normally engages the 'edge of the adjacent portion of the lever 45, locks said lever in the position shown in Fig. 5, and thereby prevents the closing of switch B until the latch is removed. This latter function is performed by the lever 50, which engages the tail 4'9 of the latch and removes it from latching position whenever the switch A is closed. vWith this arrangement of the parts it will be seen that both switches may be open at the same time, while the switch A must be closed before the switch B, as only one switch can remain in a closed position at any time. The

switch-levers are placed side by side, so that one may be held in each hand of the operator. A quick movement, simultaneously closing one and opening the other, permits transfer without stopping the motor. For instance, if it be assumed that both switches are open. and it is desired ,to start up the motor the switch B cannot be thrown, since the lever 45 will be held in the position illustrated in Fig. 5 by the latch 47. lt will therefore be necessary to first close the switch A., The closing of this switch will distend its actuating-toggle and force thi` toggle-link 26 against the lever 5() and carry it outward, so as to release the latch from engagement with the lever This will then free the lever 45 and permit the throwing ol the switch B. The throwing of the latter switch will in turn force its toggle-link 26 against the adjacent end ofthe lever 45, and in order that the toggli` may be properly extended, so as to close the switch B, it will be necessariY to open the switch A in order to remove the obstruction from the other end of the lever 45.

' Vln the system outlined when the motor 32 is once started the switch B will remain closed. ln order that this switch may therefore be automatically tripped in ease ol' overload, l have illustrated a well-known type of trip-loose connection between the operatinglever 2; of this switch and the connectinglinl( 28, which is adapted to be operated by trip-Coils 54, incloscd in a casing 55, 'formed integral with the plate '23, carried on the face of the switchboard 12. These trip devices are also of a well-known construction and comprise a movable core 56, extending downward within a Calibrating-tube 57 and provided with a projection 58, adapted to engage a ytripping-lever 59 upon the energizetion of the coil 54. A three-phase switch being shown, two of these coils 54 are employed in two legs of the circuit and each is arranged to operate on the same trip mechanism, so as to insure a tripping of the circuitrin case of dangerous conditions therein, as is well known in the art. As it is 'unnecessary to trip the switch while the motor is lied through the compensator, only the running-lever is provided with the trip-loose connection. rl`he trip-loose connection between the lever 22 and its connecting-link 2S is provided by slotting the link, as indicated at 60, so that said link may move independently of the lcver 22 'far enough to permit ,the switch to open under the action of gravity. A positive connection is established between lever 22 and the link Z8 by the employment of a toggle consisting of a link 61 and 62. These lmember 78. A

portions, whichwill be best understood bysenses links are pivoted at their non-adjacent ends to the lever 22 and to link 28, respectively. Fig.' 3 shows the toggle formed by these links distended and forming a positive connection between the lever and the link 28. ln

`this position the toggle is slightly overset, and its downward movement is limited by the 'engagem ent of the stops 63 on the link 62 with the upper edge of the adjacent portion of the link 28. .ln operation when either of the coils 54 becomes unduly energized by reason of the overloaded condition of the circuit the trip-arm 59 will be forced upward against the adjacent portion of the togglelink 6l with suilicient force to breakthe toggie, and thereby permit the link 28 to be thrown outward independently of the movement of the (merating-lever 22 in response to the normal tendency of the switch parts. For the purpose of nmintaining switches closed suitable latches 64 are provided for the operating-lcvers 22, 'lhese latches cooperate with pins 65 upon the levers and are normally held in engaging position by the springs 66, being removed from said position by the push-pins 67, extending through the handle 67L :it the outer end of the lever.

ln the altermitive form of the invention (illustrated in Fig. 9) 26 and 26b represent movable portions of the switches A and B, respectively, corresponding to the toggle-links 26', described heretofore, and the movementol` these members is obstructed, so to re- :luire a like movement of the switches A and i3. The mechanisni for accomplishing this consists of a bolt. or pin 68, slidable within a fixed bearing 69 and a riovable member 76.

'lhe bearing 69 is secured to a flange 71 of the fixed supporting structure, such as the supporting-frame il of the switch previously described, while the member 70 is slidable through .an opening in a sinlilar flange 72. The movements of' member 7() are limited by a collar 73, secured to its inner end, and a head 74, secured to its outer end. The inember 68 has secured to it a collar 75, and a coiled compressioil-spring 76 surrounds the shank of the member 68 and bears atits opposite ends against the collars 73 and 75. rl`he outer end of the member 68 is provided vwith a head 76, similar tothe head 74 on the iiieii'il m'.7(). Any sliding movement given to the member 7() will be transmittedtov the member 68 by means of a link 77, connecting the collar 73 on theI member 7() with a lever T8, which is pivotally supported midway of its length by a pivot 7) and pivo-tally secured :i1-.ils opposite end to the collar 75 on the 'lhe parts have definite procoi'isidering the operation of the device. As assumed, the member 26L is connected with the starting-switch and the member 26" with the runni'ng-switch, 'and the parts are in the positions corresponding to the open positions of the switches. It will be seen that the runnin -lever cannot beclosed, first by reason of t 1e square shoulder on head 76a, which lies inv the path of the toggle. If now the starting-switch be operate the member 26gt will be drawn outwardinto engagement with the inclined surface of the head 74,.,thereb T forcing the member 70 inward to thefdottedline position. This movement will be transmitted through the links 7 7 and lever 78 to the memben 68, and the latter will be drawn inward to its dotted line` position. This movement will carry the head 76a far enough to allow the member 26b to be drawn downward a ainst the inclined surface of said head. f this is attempted before the member 26a is returned to the position illustrated, the point 8() at the opposite end of the member 68 will come up against the member 26a,

thereby stopping its movement before the` head 76a hasbeen moved far enough to allow the member 26b to clear. From this it is apparent thatthe running-switch cannot beclosed until the starting-switch is opened. It

is also clear that thestarting-switch must have been moved part way, so as to clear shoulder on 76a. yIn fact,"as already said, the' movements of the two levers are simultaneous. As soon, however, as the startingswitch is opened the member 26b is unobstructed, and the closingymovement of the running -switch may be completed. This will force the head 80 of the member 68 into the dotted-line position 80a, and, as is clearly shown, this will prevent the closing of the starting-switch by obstructing the movement of the member 26u. However', as soon as the running-switch is opened the spring 76 will return the parts to the full-line position, and the operation above outlined may be repeated.

i From the above it will be apparent that many modifications and alterations may be made in the specific forms of' the invention disclosed without departing from the spirit and scope of the, present invention. l therefore do not wish to be limited to the exact n'iatter disclosed, but aim to cover by the terms of the appended claims all such altera- .tions and modifications.

YWhat l claim new, and desire to secure by Letters Patent of the United. States, is-

l. The combination of a plurality of electric switches, and. means for compelling both the operation of the Mvitrrlies in a definite order end the restoration of the switch last operated to its former condition before operating the next.

IOO

IIO

2. lhe combination of a plurality of electric switches, and means for compelling both the closing of the switches in a definite order and the opening of the switch last closed before closing the next.

3. The combination of e plurality of switches, e movable stop for one of said switches, means for holding seid stop in engeging position, and ineens `actuated by anothei` switch to release seid holding means and to control the position oi' seid stop.

4. The combination of a plurality. of electric switches, e movable stop for each switch, means for holding the stop of one switch in engaging position and ineens actuated by the movement of enother switch to release seid holding ineens. y

5. The combination of a plurality of electrio switches, e pivoted stop for each switch, ineens for holding the stop of one switch in engaging position', and means .actuated by the movement ol' anothei` switch to releese said holding means. v

6. The combination of a plurality of elentiio switches, e single stop inembei movable into different positions to engage the dil'eient switches, ineens foi holding seid member in engaging position foi' one of said switches,

sind means eetueted by the movement o enother switch to release seid holding Ineens.

7. The combination of two electric switches, comprising two movable elements, :i stop-arm Jivoted between seid elements and movable into alternate engagement therewith, e latch for holding seid eine in the path of movement of' one of said elen'ients,l end means actuated by the other element toI release seid lai-tolling means.

8. The eombin tion with :i paiio'f switches, of' means perinittin e free simultaneous movement of both in o posite directions, and e lock engaging seidpmeens to eompel the operation of the switches in e different order and actua-ted by one of seid switches.

ln Witness whereof I have hereunto set my hand this 27th dey of September, 1905.

onlin o. einen.

1Witnesses BENJAniN BHULL. MARGARET E. Woommn

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