US1376813A - Electeical switch - Google Patents

Description

BL D. HORTQN.

ELECTRICAL SWITCH.

APPLICATION FILED JAN. 22, 1915.

Patented May 3, 1921.

2 SHEETS-SHEET I.

INVENTOR.

ATTORNEY B. D. HORTON.

ELECTRICAL SWITCH.

APPLlCATlON FILED JAN. 22. 1915.

1,376,813. Patented May 3,1921.

2 SHEETSSHEET Z.

Ii I616 FKEU {MM ATTORNEY BRYSON HORTON, OIE DETROIT, MICHIGAN.

PATENT FEE.

' .j ELECTRICAL SWITCH.

To all whom it may concern 'Be it known that I, BRYSON D. HORTON, a citizen of the United States, residing at Detroit,-in the county of-VVayne and State of Michigan, have invented certain new and useful Improvements in Electrical Switches, ofwhich the following, taken in connection 'with the accompanying sheet of drawings, is a full, clear, and concise description thereof. I My present invention relates to certain improvements 'in that type of electrical switch commonly referred to as iron or armor-clad in which the switch mechanism is housed within a metallic protecting casing and is provided with means whereby it maybe operated from without without requiring an opening of the cover and the exposure of the live conductor parts. The object of my invention is to improve this general type of switch, to minimize the element of hazard, which is present in handling high potential currents, to improve andsimplify the mechanical construction of theswitch mechanism itself and to improve the structural form of metallic or protecting housing. Referring to the accompanying draw- 1ngs:--

F igure, 1 is a plan View of the switch mechanism embodying my invention, the cover of the casing being open to show moreclearly the arrangement of the switch mechanism;

Fig. 2 is a view, partly in section, taken on line a-c of Fig. 1;

Fig. 3 is a horizontal sectional view taken on the line 6-?) of Fig. 1 with the cover in closed position and with the handle of theswitch' in theextreme off position.

Fig. 4 is a detail in side elevation of the operating handle and oscillating spring actuated mechanism which functions to cause an abrupt and quick break between the contacts I Fig. 5 isa perspective view oi the connecting mechanism employed between the operating crank and the movable contact-actu- ZLtQIgbflI; 7 Fig.6 is a perspective view of the connect. ing device between the actuator bar and the movable blade contact;

Fig. 7is a similar view of a modified form of such crnnecting device;

Figsh8,"9 and 10 are details of modified formsof contacts and. fuse clip supports;

Specification of Letters Patent.

Application filed January 22, 1915.-

Serial No. 3,703.

Fig. 11 is a plan view of a modified form of switch mechanism in which the accelerating mechanism is located between the actuator member and the operating crank;

Fig. 12 is a vertical cross-sectional view of the modification shown in Fig. 11 with the switch mechanism in its normal on position;

Fig. 13 is a like view of the modification shown in Fig. 11 showing the accelerating spring expanded to a point where the connection between the contacts is about to be broken;

Figs. 14 and 15 are the perspective views of modified forms of accelerating spring housings and connecting links between the actuator member and the operating crank;

Fig. 16 is a View in plan of a modified form of combined handle and accelerating mechanism;

Fig. 17 is a view in side elevation thereof.

The stationary and cooperating movable contacts are mounted upon the base 1 of insulating material, which is fastened by any suitable anchoring means 2, to the base of the metallic housing 3, the housing being provided with a hinged lid or cover 4. The

stationary contacts are of the jaw type and are indicated by'the, numeral 5. These jaw contacts are provided with fuse clips 6, which may be of an integral construction, 2'. 6., they may be formed of a single stamping of sheet metal bent into :torm as shown specifically in Fig. 8. Other and cooperating fuse clips are employed to accommodate sheet metal construction, as shown specifically in Fig. 10. The movably-mounted blade contacts 9 are operated by a cross-bar or actuator member 13, this actuator member being either formed of insulating ma terial throughout, ormay comprise a metal bar enveloped by insulating sleeves 13 (as shown in Fig. 12). I find it advantageous to use a metal cross bar 13 to con- Patented May 3, 1921.

nect the movable contacts with the operating crank and suitably insulate said bar from the knife blade contacts such as by using iibrous or rubber sleeves 13, for the reason that the metal cross bar always maintains the knife blade in parallelism and in true alinement with the cooperating stationary jaw contacts. Experience has shown that where cross bars oi fibrous or rubber or other non-metallic substances are used, tlu they will frequently warp and bend, making it impossible to keep the contacts in line with each other so as to effectively cooperate. It will be noted that when the insulat ing sleeves are clamped upon the cross bar 13 by means of the members 14:, such sleeves will definitely anchor or position the connecting member or link.

This actuator bar is connected to the knife-blade contact 9, through the instrumentality of the connecting device 1%, as shown more clearly in detail in Eig. 6. This connecting device preferably is made from a single sheet of metal formed with a portion 15, conforming to the general contour of the actuator member 13, thus p;o' ,'itling a seat therefor, and a depending part 16 to which the knife-bla contact is riveted by suitable rivets 1?. order to form positive connection with the actuator bar, a screw bolt 18 is emploved. This connector may cal: the form or". piece device, such as is illustrated in Fig. the part 16 being separate from the part z. but joined together by z. screw 19. which also serves the purpose of tightening the enveloping part of the connector to the actu In order to prevent lateral disde in ator ba placement of the'two parts. the lower free end of the part i l is bent downwardly at 20 to form a rectangular abutment. This makes it obvious that in tightening the screw 19. rotary play or movement the parts will l e prevented as they re being drawn together. In order to provide for the actuation of the moifble contacts. I provide a crank 21. which is mounted in the sides of the casing substantially at point i line with the pivotal mount'" the pivoted blade contacts, thus providing ,ar a siibstantial throw or swing of the movable contacts within a given limited space. The crank 21 is connected with the cross bar or actuator member 13 through the instrumontality of a two piece connecting member 22, which comprises two sheet metal parts provided with jaw or cut-out portions at 23 oppositely (lisposed one to the other so as to confine the actuator bar within the parts The parts are held together by a bolt 24. Both part are provided with apertures 25, which are threaded upon the crank before the same is bent into form. One end of the crank 2l i' prevented from being sprung out or its bearing by the washer 26 and cotter pin 27. The

opposite bearing end of the crank shaft is mounted within two cup-shaped bearing members 28, riveted to the inner and outer sides of the casing. In order to provide for the throw of the c 'ank to manipulate the switch mechanism, an exterior handle 29 is used. This handle is of one piece construction made from a piece of tubing slotted at 30 and swaged into an intermediate fiat portion 31 and provided with curved end portions 32, the latter taking the conformation of the operating crank, and surround ingand having bearing thereon. A bolt 33 serves to hold the parts together, but not sufiiciently tight to prevent the handle from oscillating upon its bearing, to a limited ex tent, to provide for the proper manipulation of the switch.

By supporting the operating crank at both ends, or at both sides of the housing, it will be seen that substantial rigidity of construction is secured, although the parts themselves may not be carefully fitted or be of particularly substantial construction. Prefer .bly also the operating crank is connected to the actuator bar in such a way as to exert a substantially balanced pull thereon. as in this way twisting strains upon the switch mechanism are a'-7oided, the proper alineinent oi the knife-contacts with the jaw contacts is maintained, and the simultaneous breaking of both sides of the circuit is insured. in the particular example or" my inv ntion illustrated, this balanced pull is obtained by connecting the link 22 with the actuator bar substantially midway hot i on the knife-blades, although it will be understood that other rrangements secursimilar results may be employed.

These features, and also the making 01" the operating crank oi an integral bent tal are of great practical importance in the art as they contribute to the production of a switch which is strong, substantial, durable and reliable in operation, and which, at the same time, may be constructed at such a small cost as to make it arailablo for every use. This is possible because the features of construction and organization r ferred toassure satisfac -5 ope ition without requiring the use of accurately liter and machined parts which would i ake the cost of the switch prohibitive for most pur poses.

In Figs. 16 ano l? are illustrated a modified to or". operati handle which also made oi one piece, but of channel formation, h same being bowed. .'8lSG l upon c cent or self at 29, the free ends being brought t gether into rectangular formation at 29". The semicircular cut-out portions are pro- 1 ided for the accommodation of the operating crank 36.

In order to provide for a quick and rapid accelerating mechanism to which the power of a spring is utilized toeXert a force upon thecrank to' aid 1n its movement, thus making more rapid the break between the contacts; This feature of the invention com- .pr1ses a curved rod 84,- whlch 1s riveted and held fast tothe operating handle 29 at 35.

This rod ismounted to reciprocate through an aperture 60 w th n the end of the bentup portion 36 of the operating crank. Surrounding the rod 34; and held between the end of thebent-u p portion 36 anda washer 37, is a spring 38, which is compressed when the handle 29 is operated to break the connection between the contacts as will be more mechanismare of the same general character'as that heretofore descrlbed 1n connect1on with Figs. ljto 4t inclusive.

In 'FigsIll. to 13 inclusive 1 have illustrated a modified form-in which the accelerating'spring is mounted in the interior of the casing and preferably within a suitable housing at 803whichis'carried by the operatingcrank 21 at one endand in sliding engagement withthe actuator member 13 *at'its opposite end, said housing being suitably slotted at'SO to permit of the required.

lost motion tobringthe accelerating spring into-operation: T he accelerating spring 38 in thisform is directly connected atone end 31 to the operating crank,.and at the opposite endiat. 31to the actuator member.

. This is formed of a single piece of metal in channel formation, the two sides being slotted at '30 for. the accommodation and movement'of theactuator member 13 and projecting hook-like ears 32.

These ears pro ect infl diametrically opposite directions, thus forming the space 32 for the accommodation .oftheoperating crank '21.

"in; Fig. 15 the combined connecting link and accelerating spring housing is made of two partsfand. in some respects, 1s similar tothat shown in Fig. 14 excepting that the ears 132" pro ect from'the sides of the chan- .nel part in a common direction. A plate 83 .isdetachably connected to the channel part so asflto afford retaining means for the operating crank when the 'sameoccupies the space 32;.9.;;,The plate .83? is provided with apertures for the reception of the ends 33 .of-the ears 32*;and :other i apertures for the accommodation of perforated ears 33, which are formed intcgral with the sides of the channel part and project therefrom.

it will be obvious that inasmuch as the curved rod 34 moves with the handle 29' (and the latter being free to rotate on the bearing end of the crank 21) the crank 21 will not begin to move until the confined spring 38 is compressed between the washer 37 and the curved end 36 of the crank 21 sufiiciently to overcome the adherence or frictional grip'between the contacts. As soon as this is accomplished the spring expends it stored power and exerts it against the operating crankQl, causing it to swing abruptly to 'breakconnection between the contacts.

The operation of the construction shown in Figs. 1]. to13 inclusive is somewhat I analogous to the one heretofore described in connection with Figs. 1 to 4 inclusive and 16 and 17 It will be obvious that since the connection between the operating crank 21 and the actuator member is through the accelerating spring 88, and since the actuator member 13 is free to move within the con necting link or housing 30 to a limited extent, the accelerating'spring 38' is put under an expansive tension preliminary to the break between the contacts." By operating the handle 29 the crank may-be moved to the position shown in Fig. 13, at which time the contractile spring has been expanded and energ stored therein, which expendsitself in the acceleration of the movable knife blade contacts, thus causing a quick break and consequently minimizing the tendency toward arcing. If the frictional adherence between the j aw and knife blade contacts is too great to be overcome by the power of the contractile spring 38, the end ofthe con- .necting link or housingfill will engage the actuator member 13 and move it and the kni eeblade contacts to a point where the spring tension is sufficient to effect a rapid and complete break between the contacts.

The cover is provided with an enlargement 39'for the accommodation of the movable blade contacts and crank when thrown to their ofi' positions.

In order to stop and look off the switch mechanism in its inactive or 01f POSlr .ijlOll, I provide mechanism which I will now describei A plate 40 riveted to the undel" side of the cover has a depending angular extension 41. One end 41 of this depending extension is adapted, in normal operation of the switch, to engage the crank 21 when the switch is in open position and to thereby act as stop for the switch mechanism. The switch mechanism may be opened and closed as desired without any interference by this end of the extension. The extension is also provided with a notch 42 of sufficient size to accommodate the crank 21, so that after the cover has been opened and the crank moved to the extreme end of its contact breaking position, and the cover thereafter closed, the crank may be seated within the notch 42 and be prevented from moving toward its contact closing position. The contour of this notch and its location relative to the pivot of the crank and hinge of the casing is such, that when one moves the crank away from the extreme off position at the left, as shown in Fig. 3, toward the on position, the crank will be intercepted and extension 41 will engage the crank on the side thereof, facing the pivot,

so that the cover cannot be opened by forcing the crank toward on position.

I also provide, as shown in Figs. 1 and 3 a stop 40 fast to a side of the casing and in a position to intercept the crank when moved toward the extreme open position after the cover has been opened. By thus limiting the movement of the crank it is impossible to crowd the crank over against the leads, when the cover is open, thereby possibly short circuiting the line. It is also especially desirable to so limit the crank movement in switches wherein the fuses are on the side of the switches next the knife blades. Further this stop 40' cooperates with the extension 41, when the switch is locked off, to restrict the crank to a limited movement only.

It will, therefore, be apparent that the plate 40 with its depending extension 41 is adapted to function both for arresting the movement of the switch in normal operation at a predetermined point, when the switch crank 21 engages the end 41 of this extension, and it is also adapted to lock the switch mechanism at another point, namely, the extreme off position whenever it is desired to lock the switch open on account of the notch 42 engaging the switch crank 21. When the switch is locked completely off, the switch crank lies between the top of the plate 40' and the notched part 42 of the extension 41.

In order to provide for the convenien wiring of the switch, the ends of the casing are apertured at 43 and 44. The apertured end 43 is normally closed by a plate 45, provided with knock-out portions 46, which may be of the desired number to conform to the number of wires that are employed. This plate is held in place by lugs 47, and is confined within the casing by the cover thereof, when in closed position. The plate, it will be understood, may be withdrawn from the casing when it is desired to knock out the knock-out parts 46, preparatory to wiring the switch. The opposite apertured end of the casing is likewise provided with detachable or removable end plates of like mounting, excepting that the plate itself is provided with an oblong slot in which is mounted a porcelain insulating bushing 48, provided with suitable holes 49 conforming in size to the particular wires that are employed.

I do not wish to be understood as limiting myself to the precise structure shown and described as the same may be varied and departed from and still be within the spirit and scope of my invention as set forth in the appended claims.

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

1. In combination with a metal. housing, of a base, a plurality of stationary contacts mounted on said base, a plurality of knife blade contacts pivotally mounted at one end to said base and adapted to cooperate at then other ends with said stationary contacts, a cross arm secured to said knife blade contacts at a distance removed from the free ends of said blade contacts, a crank mounted to swing about an axis in alinement with the axis of said knife blade contacts, said crank having an elongated portion parallel with sald cross arm, and lateral arms shorter than said knife blade contacts, an elongated link connecting the elongated portion of said crank with the middle of said cross arm, a handle secured to said crank and disposed exteriorly of said metallic housing for operating said crank, a cover for said metallic housing, and an obstruction on said cover engaging said crank when the switch is in ofi' position and the cover has been closed thereby locking the switch in such off position.

2. In an armor clad switch, in combination, a metallic housing comprising a cover, sides and a hinge between said cover and one side, and a switch mechanism including a crank journaled in one of the sides of the housing, said cover carrying a depending extension projecting into the housing and having a notch therein, a wall of said notch being disposed, when the cover is closed and the crank is in the off position, in the path of the crank to intercept it when moved toward the on position, a portion of said extension comprising means to engage the crank, when so intercepted, and prevent the opening of the cover by the crank, substantially as described.

3. In an electrical switch, the combination of a housing, a base of insulating material therein, a plurality of spaced stationary contacts on said base, a plurality of knife blade contacts pivotally mounted at one end on said base, a transversely extending actuating member extending over said knife blade contacts and rigidly connected thereto, at a distance removed from their free ends, an operating crank mounted to swing about an axis in alinement with the axis of said knife blade contacts, and having a portion extending over and substantially parallel with said actuating member and lateral arms shorter than said knife blade contacts, an elongated link connecting said crank portion with said actuator member at an interme diate position on said member and an operating handle mounted exteriorly of the housing and operatively connected to said crank to manipulate the crank and said contacts.

4. In an armor-clad switch, in combination, a metallic housing comprising a cover, sides and a hinge between said cover and one side, and a switch mechanism including a crank journaled in one of the sides of the housing, said cover carrying a depending extension in the path of the crank when the cover is closed, to intere'ngag'e with the crank when moved from the extreme off position toward the on position, said extension comprising means whereby when the cover is closed and the crank is so moved the crank and extension parts will interlock so that forcing of the cover open by the crankwill be prevented substantially as described.

5. In an armor clad switch, the combination with a metallic housing comprising a movable cover and sides, and a switch mechanism including a crank journaled on one of the sides of the housing, of means on the cover, when closed, for locking the crank in the limiting position of its movement, and means on said housing and cooperating with the locking means on said cover to limit the oscillation of said crank when the switch is locked in off position.

In witness whereof I have hereunto set my hand in the presence of two subscribing witnesses.

BRYSON D. HORTON. Witnesses:

HARRY S. FREEMAN, IGNATIUS W. KAHN.

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