US1414421A - Double-throw switch - Google Patents

Description

L. F. KRIES.

DOUBLE THROW SWITCH.

APPLICATION FILED AUG.17.I9I7.

Patented May 2, 1922.

4 SHEETS-SHEET I.

l llllll -L. F. KRIES.

DOUBLE THROW SWITCH. APPLICATION HLEn AumH. 1917.

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L. F. KRIES DOUBLE THROW SWITCH. APPLICATION FILED AUGJT, I917.

Patented May 2; 1922.

4 SHEETS SHEET 3. 6

. QW- MI L. F. KRIES.

DOUBLE THROW SWlTCH. APPLICATION man Aue.n. 1917.

Patented May 2, 1922.

4 SHEETS-SHEET 4.

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UNITED STATES PATENT or rica.

LAWRENCE I. KBIES, OI BALTIMORE, MARYLAND, ABSIGNOB- TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, 'OF EAST PITTSBURGH, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

Tb aZZ-whom it may com.em.'\ 7

Be it known that I, LAwREN'onF. Kmns,

a vcitizen of the United States,-residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Double-Throw Switches, of which the following is a specification.

I This invention relates toelectric service boxes, and more particularly to a combined switch and fuse box of the }general type shown in my prior'Patent 0. 1,224,880, granted May 1, 1917.- 0

. The primary object of the present invention is to provide'a switch box of this character'equipped with a double-throw switch and two sets of fuses. Such a box is especially adapted forus'e where two feeder circuits are to be supplied from one'set of mains, or where a sin le feeder is to be supplied from either 0 two sets of mains.

It also has utility in circumstances where it is desirable to provide two sets of fuses between a single feeder and a single main so arranged that either set may be'thrown into the circuit.-

Among other objects of the invention are 'to so construct the box as to render it absolutely safe under all conditions, and to positively prevent thepossibilityof the uni authorized taking of current therefrom. I also contemplate certain im roved structural features, by virtue of w ich the parts of the box may be more-readily assembled I and the various switch contacts conveniently connected to the respective conductors. Additional objects and advantages of the inventionwill be'app'arent from a detailed description thereof.

-the--direction of the arrow;

In order that the invention may be clearly understood, reference is'had tothe accompanying drawings; forming a part'of this specification, and inwhich,

Fig. 1 is a central, longitudinal section through 'my improved switch box, showing the switch inoneof its operative positions; Fig. '1 is a view ofa stoppage screw which I- may employ;

Fig. 2 is .a view similar to Fig. 1, but showing the switch in neutral position;

i Fig. ,3. is a sectional plan of the box,- taken onfthe line13-3 of Fig 1;

Fig. A isa transverse section, substan "many on the line 4-401 Fig, 2, looking in I Specification of Letters Patent.

taining the fuses. I

2, the lower part of the partitions 3 and doors E and F, respectively. r fReferring now to Fig. v6, the .baseeplate 1' partially removed '7", such P01110115] apted to be. knocked out Fig. 6 's" a perspective view of the bot-,

tom of the box, or base plate;

v Patented May 2,1922. a ummnmedau it 17, mm Serial No. mam.

Fig.7 is an end 'elevation of the box, showing means for coupling a cable conduit thereto; i Fig. 8 is a perspective view showing a slightly modified construction of one of the sector-shaped end plates formingpart of the switch structure;

Fig. 9 is a. fragmentary, sectional view, similar to Fig. 1, showing a slightly'modified arrangement.

Fig. v10 is a sectional elevation of the double-throw switph member, showing a modified construction in which fuses are in ter osed in the switch blades;

ig. 11 is a sectipnal elevation; on'an eularged scale, taken on the line-1111 of Fig.

10,d looking in the direction of thearrow; n 7 i i 12, 13, and 14 are diagrams illus.

which my improved switch-box can be emplo ed.- r

eferring to the'drawings in detail, and particularly to Figs. 1 to 6 thereof, my improved box consists of a base plate or bottom 1, and a casing 2. These may be of cast or sheet metal and are preferably free from seams, joints, or projecting bolts other than those shown in thedrawing and nowto be described.

The *casing or container is divided, by

means of the partitions 3 and4, into aeentral compartment A, containing the switch,

'trating various circuit arrangements with and two end compartments B and .0, con-' As shown in Figs. 1 and above referred to. The switch compartment Afisprovided with a .door D, and the fusd compartmentsB and Care provided with is formed with upstanding marginal s'eg:

ments 7 and 7, and similar end segments 8-and 8". These, segments are preferably I formed at the factory, with eakened' or ortions, as dicatedlat when the box is installed to form enings I such as 78, for the reception of t 1e con duits. Similar weakened portions 9 are preferably formed in the bottom plate itself so that conductors can be brought in from the-back, if desired, as is the common practice in junction boxes.

The plate 1 is provided with a series of base X rests upon these bosses and is secured in position by means of screws 19 passing through the same.

The plate 1 is further provided with upstanding perforated lugs 13 at its edges,

such lugs being adapted to fit on the inside of the walls of the casing 2, and the casing is attached to such lug by means of screws 20 put in from the inside, as shown in Figs. 1 and 3.

Several methods of attaching the cable conduits to the box may be employed. As

' shown in Fig, 7. and at the left of Figs. 1

and 6, themethod which I prefer to employ is as follows: The conduit 16, which in this instance, consists of a metal pipe, is threaded at its end and has a collar 15 screwed thereon. This collar is largerthan the opening 8 in the segment 8 and is held against the outer face of such segment by means of a yoke 14, slipped over the end of the pipe before the collar is attached and secured to the segment 8 by means of screws 17, passing through holes 18 in the segment and inserted from the inside.

Another method is similar to that shown in my patent above referred to, and is illustrated at the right of Fig. 1. This consists in providing a tapering threaded nipple 22, which is secured into the openin in the segment 8. The end of the con uit 21, which in this case may be a lead pipe, is expanded over the end of the nipple 22 and is secured in position by means of'a yoke 23, held on by screws from the inside.

Openings 2' are formed in the sides and ends of the casing, shaped to conform with the segments 7 and 8. and arranged to overlap the edges of such segments. Inwardly projecting tougues'2 are formed integral with the walls of the casing and are adapted to engage the inside of the upper edges of the segments 7 and 8. 4

Mounted upon the base X in the middle of the compartment A. is a double-throw switch S, shown as a three-pole switch. This suitable insulating material, and the ends of these bars are themselves secured to seetors 30 and 31, which serve to hold the parts of the switch'rigidly together; The sectors 30 and 31 are themselves pivoted at '32 and 33, respectively, to brackets 34 and 35, mounted upon the base X, the pivots 32 and 33 being inline with the pivots 26 so that the whole switch structure turns together about the common axis.

The switch blades 24 are arranged to engage and bridge clips or contacts 36 and 38, while the switch blades 29 are arranged to engage contacts 37 and 39, all of these contacts being mounted upon the base X. Associated with the contacts 38 and 39 are binding posts 40 and 41, respectively, to which the conductors which run underneath the base are connected. Extending under the partitions 4 and 3 are conductin strips 42 and 43, respectively, connecting t e contacts 36 and 37 with fuse clips 44 and 45, respectively. Other sets of clips 48 and 49 are provided and are associated with binding posts 50 and 51 to which the conductors are attached. Suitable fuses 46 and 47, here shown as being of the cartridge type, are held in the clips 44-48 and 45-49, respectively. In order to indicate to the operator the position of the switch a target or dial plate 53 is attached to one of the sectors, such as 30, and has on its outer face the words On-Neutral-On, and the wall'of the casing 2 is provided with a window 52, through which these words may be read.

In order to actuate the switch manually, operating means extending outside of the casing are provided. Such means consist of a pair of bail-shaped members 54 and 55, preferably formed of relatively thin, flat strips of metal set edgewise and having at their ends the handle portions 54 and 55", respectively. These bails are slidably mounted in the end wals of the casing 2 and in the partition walls 3 and 4 and are united at their ends in the central compartment A by means of joints is.

Adjacent each compartment B and C, the legs of the bails 54 and 55 are cut away to form elongated notches 56 and 57, respectively, Thesenotches have curved ends and co-operate with tail pieces 60 and 63 of the doors It and F, which are pivoted at 58 and 61, respectively. The doors E and F are flat, as indicated at 59 and 62, respectively, but may be provided at their ends with upstanding flanges and 74, respectively, adapted to lie flat against the inside of the one or bothlegs with a series of holes 7 7 67778-7 9'and 7 9, for a purpose hereinafter described: The connection between the bails 54 and 55,.which together constitute an operating member, and the switch S consists of a pair of shouldered bolts 80 and 81, respectively, fastened in the legs or sides of the bails and adapted to engage notches .82'and 83, respectively, formed in the upper edges of the sectors 30 and 31.

A pair at locking devices in the form of ordinary sliding bolts S t-85 are secured to the partition walls 3 and 4c in the switch compartment in such position as to be capable of engaging the holes 75-79, etc., in'the operating member. A stop screw 86 (Fig. 1 is also adapted to be set into any desired one of these holes so as to limit the movement of the operating member, as desired. This may be done for the purpose of insuring the stoppage of the switch in neutral position, as shown in Fig. 2, or for other purposes.

The door D of the switch compartment consists of a flat sheet of metal 87, preferably having a glass window 88 set therein and pivoted at 89 to the casing. "llhe door may be provided with an u standing flange 30, adapted to receive a sea 91-, and isalso equipped with a lock and key 92--93, so that access to the switch compartment 'byun authorised persons can be prevented.

Means are also provided for locking the operating member so as to maintain the switch in any desired position. As shown in the drawings, this is accomplished by arranging perforated lugs 9495' at each end of the'box adjacent the respective bail members. When one of the holes, such as 78,

registers with the opening 96 in one of the lugs, such as 94 or 95, a padlocltfl97 is in sorted in the alined openings and the-parts thus locked in position. v

' As shownin Rig. 9, I may provide binding posts such as 98in connection with the conducting strips 42 and 4 3. These binding posts. as indicated in Fig. 12, 13, and 14, are for the purpose of attaching the meter and ground connections. It is. also often desirable in a three-wire system, where the neutral is grounded, to make the neutral solid so that the ground connection cannot be interrupted. For this purpose, I provide a conducting strip 99, embedded in a groove in the back of the base X, as shown in Fig. 9. and attached to the bottom of the clips ordinarily used to support the fuse 47.

With this arrangement, it will be seen that it is. immaterial whether the fuse is absent or resent.

igs. 12, 13, and 14 illustrate three difierent applications of my improved switch and fuse box to the control of commercial circuits. In Fig. 12, is shown a feeder system 100, adapted to supply current to either one of two load circuits or mains 101 and 102.

The switch contacts 38 and 39 in this instance are joined by means of conductors 103, arranged'on the back of the base, and the feeder conductors are attached to these contacts. When the switch is in one on position,' current is supplied through the switch blades 24 to the mains 101, and when it is in the other on position, current is supplied through the switch blades 25 to the load 102. When in neutral position, both circuits are open. Fig. 13 illustrates another common tion in. which two sets of feeders E k-105 are arranged to supply a single load circuit 106. This is' the case where a building is supplied with current either from its private plant or from the city mains and a doublethrow switch is employed for throwing over from one source of current to the other., The binding posts 50 and 51 are connected the'back ot the base by meansof conductors 107, and the load wires 106 are also connect edto these binding posts. This is the arrangement of circuits corresponding with the location of conductors shown in Figs. 1, 2, and 4;.

in Fig. 14 is illustrated anarrangernent in which a single feeder 108 supplies current to a single'lcad'ciruit 109, but in which it is possibie to feed the current through either one of two sets of fuses by throwing the switch from one. position to the other, as will be obvious.

I ltn installing my improved box in a building, the method hereinafter described is iollowed. The plate 1 is first mounted upon the wall or other suitable support and secured in position by means of screws. The conduits such as 16 and 21 are then attached to the respective segments, such as 8'and8', and the several conductors laid out upon the plate 1 and their ends bent up at pomts approximately corresponding with the locationof the holes throughthe-base X. Thebase withthe switch and fuse mounted thereon is then placed in position over the platev 1. the free ends of the conductors being threaded through the respective'holes and. attached tothe proper binding posts. Thebase is then firmlv anchored by means of' the screws 19. After the electrical connec tions have thus all been made, the casing 2 is placed in position over the base, the bolts 80 and 81 being slipped into the respective notches 82 and 83. It will be seen that the lower edgeof the casing 2 embraces the lugs ment whenever the switch is closed so as to supply current to the fuses in thatcompart-v ment. In other words, referring to Fig. 1, the door F of fuse compartment Q is locked because the switch S is in a position to supply current through the fuses 47 in suchcompartment. In' this position of the switch, however, the fuses in compartment .B are dead and the door E of this compartment is free to open. The switch compartment A is. of course, closed at all times and the switch and all live current carrying parts are inaccemible to unauthorized persons. In Fig. 2, the switch is shown in neutral position and the notches 56 and 57 are so proportioned that both doors E and-F are locked. It will be obvious, however, th'at'it is possible to shift the operating member slightly in either direction a sufficient distance to cause the edge of one of the notches to clear the tail piece of the corre sponding door so as to permit such door to be opened without bringing the switch blades 24 or 25 into engagement with either set of contacts; In this way, either set of fuses 46 or 47 can be inspected or replaced without closing either circuit.

When it is desired to use the switch so as to normally operate between the neutral and one on position, the stop screw 86 can be inserted in one of the holes, such as 75 or 7 9, and this stopscrew, striking against the corresponding partitions 3 or 4, will prevent the switch movingpast neutral position. When it is desired to use the other side of the box, this stop screw may be removed or shifted. The sliding bolts 84 or 85 are adapted to enter the holes 75, 76, 77, or 79, to lock the switch in either of its closed or its peutral positions. As above pointed out, when the switch is locked in its neutral position,.as shown in Fig. 2, both fuse compartments are also locked so as to prevent unauthorized tampering. This is a desirable feature in cases where it is necessary to permanently interrupt the, supply of current through the switch for an extended period.

, In order to insure the doors E and F being closed or moved to locking position prior to the throwing of the switch. I preferably provide light helical springs 58' and 61', attached to the inside of these doors, respectively, as shown.

With my improved box as herein described, .it is possible to construct the switch as shown in Figs. 10 and 11, with an extra set of overload or emergency fuses. Referring to these figures, it will be seen that in the switch blades 24 and 25' are interposed clips c.

sections of insulation a and b, and on either side of such insulation are secured fuse These clips are adapted to can cartridge fuses e and f, respectively. Such fuses are of greater capacity than the service fuses 46 and 47, but, being inaccessibly enclosed in the compartment A, serve to protect the circuit against .accidents which might be caused by re-fusin the com artnients B or G with excessive y heavy uses. The lower ends of the clips 0 are preferably made wedge-shaped, as shown at d, so as to enable them to easily enter the switch contacts.

In some cases it ma be desirable to form the switch sectors as s own at 30 in Fi 8,

in which a closed slot 82 is provided in p ace of the open notch 82. With such a construction, of course, a different method of assembling must be employed.

What I claim is:

1, The combination with a casing having a pair of openings, and a separate door or closing each opening, minals in different parts of the casin each set bein accessible through one of sai openings, w en the corresponding door is open,

of two sets of fuse tersupply wire terminals and live switch contacts in still another part of the casing, means for preventing access through either of said openings to said line terminals and switch contacts, a movable switch member within the casing for selectively connecting said switch contacts with either of said sets of fuse terminals, and means operatively related to said doors and switch member necessitating the closure of each door prior to the closing of the switch in such manner as to connect with the corresponding set of fuse terminals, and the opening of the switch prior to the opening of each suchdoor.

2. The combination with a casing divided into three compartments, of a switch in one compartment, and fuse. terminals in the other compartments, said switch serving to.

ments, and a double throw switch in said middle-compartment controlling the supply of current to the fuse terminals in said end compartments, and actuating mechanism for the switch operable from without the casing, said mechanismand both of said doors having interlocking parts acting to automatically lock either door in closed position when,

a switch compartment, and two separate fuse compartments, of a double-throw switch in.

the switch compartment having a neutral and two on positions, fuse terminals in the fuse compartments, said switchserving when in each of its on positions-to connect the fuse terminals in one or the other of the fuse compartments with the source of current, doors for said fuse compartments, and operating means for the switch co-operating with said doors so as to necessitate the closing of the door of either fuse compartment before the switch can be thrown to the corresponding on position '5. The combination with a casing having a central and two end compartments, of a switch in said central compartment, having two on positions, and a neutral position intermediate said on positions doors for said and com artments, and actuating reach anism for said switch, said mechanism coinprismg'means for iocinng one of the doors when the switch is in either of its orrpositions, and for locking both doors when the switch is in neutral position,

6., The combination with a casing-having a switch compartment and two fuse compart,

ments, of a double-throw switch in the ,switch compartment, and fuse terminals in the q fuse compartments, switch actuating mechanism compr sing a shdable member extending through aii three compartments, and

doors 1101 said fuse compartments, both said doors having parts disposed in interioching reiation with said member whereby bothdoors are locked closed when the switch is in neutrai position.

7, The combination with a casing having a switch compartment and two fuse compartments, of a double-throw switch in the switch compartment, and fuse terminals in the fuse compartments, switch actuating mechanism comprising a slidabie member lymg partly within all three compartments, doors for said fuse compartments having parts dis osed in interlocking relation with said mem er, and said member havin a pin and slot connection with said switch w ereby both doors are locked closed when the switch 'is in neutral position a 8. The 'combinatlon with a casing having three compartments, of a switch and two sets of fuseterminals adapted to be alternativelyconnected thereto and all disposed in separate compartments, actuating mechanism for said switch and means whereby access'to said sets offuse terminals is so selectively controlled by the switch-actuating mechanism that, when the switch is conndcthaving two on positions,

ed to one set of fuse terminals, such terminals are rendered inaccessible and the. other set of fuse terminals are rendered ac cessible. Y

9. The combination. with a casing having three compartments, of a switch and two sets of fuse terminals adapted to be alternatively connected thereto and all disposed in separate compartments, a door for each nected to one set of fuse terminals, suchterminals are-rendered inaccessible by the door for their respective compartment and the other set of fuse terminals are rendered accessible.

10'. The combination with a casing comprising separate switch and fuse compartmer ts, of a switch in the switch compartment, operating means for the switch projecting' outsideof the casing, 'a door preventing access to the switch compartment, and means in said switch ecompartment for locking said operating means against movement in its open or closed position.

11. The combination with a casing comprising separate switch and fuse compartments, of a switch in the switch compartment, operating means for the switch projecting outside of the casing, a door for the fuse compartment having a part interlocked with said operating means, another door, controlling access to the switch compartment, and means in said switch compartment for locking said operating means against movement.

12. The combination with a casing having doors, of an inaccessible double-throw switch mounted therein, two sets of fuse terminals in said casing, access-to which is controlled by said doors, and the supply of current to which is controlled by said switch, means extending outsidethe casing for non mally actuating said switch to throw it from one operative position to the other, and means inaccessible to/the operator, for limiting the movement of the switch to prevent it from being thrown to one of its operative positions. l

13,, The combination with a casing having a pair of doors, of an inaccessible doublethrow switch mounted therein, said switch and a neutral position intermediate said on positions,

and actuating mechanism for said switch, I

said mechanism comprising means for locking one only of said doors when the switch is in either of its on positions or between the neutral position and either oniposition, and'fo'r locking both's'aid doors when the switch is in neutral position.

14. The combination with a casing hav-v ing a pair of doors, of an inaccessible doublethrow swltch mounted therein, said switch having two on posltlons, and a neutral 'position intermediate said on positions,

and actuating mechanism for said switch, said mechanism comprising means for locking both said doors when the switch is in neutral position, and for releasing one or the other of said doors when the switch is shifted from such neutral position toward the respective on.position.

15. The combination with a casing having a switch compartment and two fuse compartments, a fuse in each fuse compartment, a double-throw switch in the .switch compartment for alternatively connecting the fuses thereto'and a door for each fuse compartment, of means for so interlocking the doors with the switch that, when the switch is connected to one of the fuses the door for its respective compartment 1s held in closed position. J

In testimony whereof I' have afiixed my signature.

LAWRENCE F. KRIES.

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