US2252901A

US2252901A - Disconnecting switch

Info

Publication number: US2252901A
Application number: US381267A
Authority: US
Inventors: Edward F Sixtus
Original assignee: PACIFIC ELECTRIC Manufacturing CORP
Current assignee: PACIFIC ELECTRIC Manufacturing CORP
Priority date: 1941-03-01
Filing date: 1941-03-01
Publication date: 1941-08-19
Anticipated expiration: 1958-08-19

Description

Aug. 19, 1941. E. F. SIXTUS 2,252,901

mscommcmue SWITCH Filed March 1, 1941 I INVENTOR. Eon/men F. S/x rus BY y,

Patented Aug. 19, 1941 DISCONNECTING SWITCH Edward F. Sixtns, San Francisco, Calif., assignor to Pacific Electric Manufacturing Corporation, San Francisco, Calif., a corporation of California Application March 1, 1941, Serial No. 381,287

IClaims.

The present invention relates to electrical switch apparatus, and more particularly to disconnecting switches of the type used in sectionalizing and interrupting high tension electrical transmission lines.

An object of the invention is to provide an efiicient switch and operating means that is adapted for use in connection with either single or multiphase circuits, where it is desired to seetionalize a power transmission line or to open or close a branch circuitat-the point of connection with the main line. or for the protection of am! electrical equipment that may be operated from a high voltage transmission line.

Switches of the character contemplated by the invention are generally mounted in the open where they are subjected to all conditions of weather and, as a result, it is necessary that the cooperating contacts of the switch be arranged so that they can be easily opened and closed under normal and abnormal weather conditions. Therefore, it is another object of the invention to provide an improved contact arrangement for a switch that can be operated under all weather conditions and also provide a positive contact between a stationary contact terminal and a movable switch blade.

Another object of the invention is to provide a stationary contact for an electric switch that will make a wiping contact with the switch blade as the latter engages the stationary contact and thus insure a good electrical contact under all conditions of operation.

A further object of the invention is to provide a stationary contact and moving switch blade of special construction which will produce a high pressure contact between the parts and also provide for the dissipation of heat.

Other objects and advantages of the invention will be in part evident to those skilled in the art and in part pointed out hereinafter as the description thereof proceeds.

For a better understanding of the invention reference should be had to the following description taken in connection with the accompanying drawing, wherein there is shown by way of illustration and not of limitation a preferred embodiment thereof. 7

In the drawing:

Figure 1 is a view in elevation showing the invention as applied to a disconnecting switch of the so-called tilting insulator type,

Figure 2 is an enlarged fragmentary view of the contact arrangement with portions removed to disclose details of the contact formingelements,

Figure 3 is a sectional view taken along line III-411 of Figure 2,

Figure 4 is a view similar to Figure 2 showing a modified form of the invention, and

Figure 5 is a sectional view taken along line VV of Figure 4.

In disconnecting and other high voltage switches, particularly those which are used infrequently or which are placed in the open and exposed to the elements, it is quite necessary that the operating parts be constructed so that they will not become inoperative owing to lack of lubrication or because of the contacts sticking or freezing due to poor electrical contact. This sticking of the switch contacts in opening or closing may be caused by corrosion of the contacts, ice and snow in the winter, or an accumulation of dirt in the summer and is quite prevalent in switches of the type having contacts that make a sliding engagement with each other.

In accordance with the present invention, the switch contacts are so made that the accumulation of dirt, corrosion, ice and snow, or loss of lubricant affects the opening or closing of the switch but little. The construction of the switch contacts are such that they can be operated with a very small eflort and brought into full cooperating relation with a perfect wiping and high pressure contact without adding any additional load upon the operating means. A further advantage obtained by the arrangement disclosed is that lighter insulators and actuating means are required than is the case where the switch contact pressure is produced by a final movement of the switch operating means.

In Figure 1 of the drawing the invention is shown, for the purpose of illustration, as applied to a disconnecting switch of the so-called tilting insulator type. In this arrangement the switch comprises two stationary insulator stands i0 and II that are secured in spaced relation upon a suitable support I2. The insulator stand in is here shown as having a stationary contact forming cap i3 at its outer end andthe' insulator stand H is shown as having a terminal forming cap It at its outer end. The stationary contact forming cap i3. has a terminal portion IE to which one side of the transmission line is adapted to be connected, and the terminal forming cap ll has a similar terminal portion ii to which the other side of the power line is connected. The cap it upon the insulator stand it is also shown as having'an upwardly extending contact forming portion I! with which a pivotally mounted .switch blade I9 is adapted to cooperate, as will be hereinafter pointed out. The switch blade I9 is here shown as mounted upon the outer end of a tiltable insulator stand l9 which is pivotally mounted by means of a shaft 29 upon a pedestallike support .2| that is secured upon the support |2 between the insulator stands i9 and II. For the purpose of connecting the switch blade I9 with the terminal portion l9 upon the insulator cap ll, there is a flexible current carrying conductor 22. In order to prevent this current carrying conductor 22 from interfering with the pivotal movements of the insulator stand l9, it is supported intermediate its ends by spaced links 23 and- 24 which are hingedly secured at their sides to the insulator stands Ii and i9. In the particular switch here illustrated the tiltable insulator stand I9 is shown as secured to the shaft 20 by a clamping bracket 25 that extends downwardly and carries a rocking shaft 26 by means of which any number of these switches may be operated in unison to simultaneously interrupt the several circuits of a multiphase power transmission line. The rocking shaft 29 also carries a suitable operating lever arm 21 by which a tilting movement may be imparted to the insulator stand H to thus move the switch blade l9 into and out of cooperating relation with the contact forming portion I! carried by the insulator stand l9. At this point it will be noted that the pedestal-like support 2| is of overhanging construction and, therefore, does not interfere with the rocking movement of the operating shaft 29. Before passing on to the remaining figures of the drawing for a more detailed description of the invention, it should be noted that the switch blade I9 is here shown as having a depending end 29 that is adapted to move into overhanging relation with the contact forming portion ll upon the insulator stand i9 and engage two contact forming members 29 that are movably carried by the contact forming portion H, as will hereinafter appear.

Upon referring to Figure 2 of the drawing it will be seen that the contact forming portion l1 upon the stationary contact forming cap I3 is provided with a diagonally disposed slot 39 adjacent which there is a raised contact forming surface 3|. In practice this raised contact surface the contact forming portion II and the switch blade l9. These pressure exerting springs 39 are secured in place between the discs 29 and spring seats 31 by means of nuts 39 which are threaded upon the ends of the shaft 33. With this ar- 7 rest against the projecting upper end of the consame tact forming portion I1 and at the same time the contact forming members or discs 29 willassume a position, as shown, where they will form oppositely disposed bridging conductors between the contact surfaces 3| and 32 carried respectively by the contact forming portion and' the depending end 29 of the switch blade l9. When the parts are in thi position, it will be noted that theshaft 33 is at the lower end of the slot 39 of the contact forming portion I1 and thus the contactforming members 29 will be held against any further downward movement as the switch blade l9 moves into engagement therewith. Now, should the switch blade i9 be rocked upwardly, as is the case in opening theswitch, the raised contact surfaces 32 upon the switch blade |9, due to their frictional engagement with the discs 29, will cause these discs to be carried upwardly therewith and turned about the shaft 93 so that the discs 29 may be said to move with a rolling or wiping action over the contact surfaces 3| upon the contact forming portion I'l. At the time the shaft as will be carried along therewith until it reaches the upper end of the slot 30 where the raised contact surfaces 32 will become disengaged from the discs 29. When this occurs, the discs 29 will be held in this uppermost position by their frictional engagement with the contact surfaces 3| upon the contact may be of silver, if desired. It will be understood that a similar raised contact forming surface is also provided in a corresponding position upon the other side of the contact forming portion H. The depending end 29 of the switch blade I9 is also shown as provided with raised contact forming surfaces 32 upon its opposite sides. These raised contact forming surfaces 32 upon the switch blade I9 are so positioned that when the switch blade is in its circuit closed position they will assume a position at the side of said slot 39 opposite the raised contact forming surface 3| upon the contact forming portion i1. Extending through the slot 39 there is a shaft 33 upon which the contact forming members 29 are mounted. The contact forming members 29 arehere illustrated as discs having a beveled edge 34 andwithin the limits of this beveled edge they are preferably provided with a silver contact making surface 35 that is of a diameter suflicient to bridge over the raised contact surfaces 3| and 32 formed respectively upon the stationary contact forming portion I1 and the movable switch blade I9.

forming portion I]. At this point it should be noted that the contact surfaces 3| are disposed nearer the axis of the shaft 33 than are the raised contact surfaces 32 upon the switch blade and, as a result of this disposition of these contact surfaces, the forces exerted upon the discs 29 by movement of the switch blade |9 will be applied at a greater distance from the axis of the shaft 33. This insures a rotation of the discs 29 as the Switchblade 9 is moved out of or into its final circuit closed position with respect to the contact forming portion il. When the switch blade I9 is in its open circuit position and is brought into engagement with the discs 29, with the latter in their uppermost position as above described, the raised contact surfaces 32 upon the switch blade |9 will impart a reverse rotation to the discs 29 and cause them to roll downwardly until the switch blade l9 has reached its fully closed position, as illustrated.

Reference is now made to Figures 4 and 5 of the drawing wherein the invention is shown as embodied in a different form. As here shown, the switch blade, dasignated by the numeral 33,

is of the conventional type and is preferably pro vided with raised contact surfaces 49 on opposite sides at the extreme end thereof. The switch blade 39 with its raised contact surfaces 40 is adapted to move between two spaced contact forming members or discs 4| which may be similar to the discs 29 described above. These discs 4| are mounted upon a shaft 42 which extends transversely through an elongated slot 43 formed in a stationary contact forming portion 44 provided upon an insulator terminal cap 45 that is secured to the upper end of an insulator stand 45. The stationary contact forming portion 44, like the contact forming portion |'I above described, is provided with raised contact surfaces 41. In this arrangement the contact forming surface 4|) upon the switch blade 39, and the contact forming surfaces 41 upon the stationary contact forming portion 44 are arranged at equal distances on opposite sides of the axis of the shaft 42 so that when the shaft 42 is in the bottom of the slot 43 and the switch blade 39 has come to rest against a stop 48 that is carried by the stationary contact forming portion 44, these contact surfaces will be in full contact making engagement with the contact forming members or discs 4|. From this it will be seen that when the switch blade 39 is moved upwardly, as during the initial circuit opening operation thereof, the discs 4| will be rotated counterclockwise with respect to the axis of the shaft 42. This rotation of the discs 4| will cause them to move upwardly with the shaft 42 until the shaft 42 engages the upper end of the slot 43. At this point further movement of the switch blade 39 will cause it to become disengaged from the discs 4| where they will remain until the switch blade 39 has been again brought into engagement therewith, as during a final circuit closing movement of the switch. In this latter event, when the raised contact surfaces 40 upon the switch blade 39 engage the discs 4|, they will be caused to turn clockwise about the axis of the shaft 42 and consequently move downwardly with a rotary or'wiping action until the switch blade 39 has engaged the stop 48. At this point the contact forming surface of the discs 4| will be in full circuit making engagement with the contact surfaces 40 and 41 carried respectively by the switch blade 39 and the stationary contact forming portion 44. As is more clearly illustrated in Figure 0f the drawing, in this embodiment, the shaft 42 uponwhich the contact forming members or discs 4| are mounted, is in the form of a bolt having a castellated nut 49 at one end thereof. It will be also noted that instead of the helical springs 36, as described above, the contact forming members or discs 4| are biased into high pressure engagement with the contact surfaces 40 and 41 by means of springwashers or discs 50 that are interposed between the outsides of the discs 4| and the head or nut 49 carried by the shaft 42.

While the invention has been described above as contemplating the use of silver as a means to provide a good contact surface between the circuit interrupting members, it will be understood that any other suitable conducting material may be used at these points. It is also contemplated that in low capacity switches these raised surfaces may be omitted entirely. In this latter event, the discs 29 or the discs 4| will be brought into direct engagement respectively with the opposite sides of the stationary contact forming While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illustrated specific devices and arrangements, I desire to have it understood that this invention is not limited to the specific means disclosed, but may be embodied in other ways that will suggest themselves to persons skilled in the art. It is believed that this invention is new and all such changes as come within the scope of the appended claims are to be considered as part of this invention. 7

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

l. A full wiping contact for an electric switch, comprising a stationary terminal having an extending blade-like portion with contact surfaces on opposite sides thereof, said blade-like portion also having an elongated slot disposed adjacent portions l1 and 44 and the ends of the switch blades l8 and 39.

and at oneside of its contact making surfaces, 9. switch blade adapted to move relative to said blade-like portion having contact making surfaces on its opposite sides adapted to be disposed at the other side of said slot when said switch blade is in its closed circuit position with respect to said stationary terminaLtwo spaced circuit forming members disposed one on each side of said blade-like portion adapted to bridge the contact surfaces on the corresponding sides of said blade-like portion and said switch blade, and a supporting means for said circuit forming members extending through said elongated slot and adapted to move therealong as said switch blade is moved into and out of engagement with said circuit forming members, whereby said circuit forming members will be brought into good contact making engagement with the contact surfaces upon the opposite sides of said stationary blade-like portion and said switch blade with a wiping action.

2. A full wiping contact for an electric switch, comprising a stationary terminal having an extending blade-like portion with contact surfaces on opposite sides thereof, said blade-like portion also having an elongated slot disposed adjacent and at one side of its contact making surfaces, a switch blade adapted to move relative to said blade-like portion having contact making surfaces on its opposite sides adapted to be disposed adjacent and at the other side of said elongated slot when said switch blade is in its closed circuit position, two oppositely spaced discs disposed one on each side of said blade-like portion adapted to bridge the contact surfaces on the corresponding sides of said blade-like portion and said switch blade, and a supporting shaft for said spaced discs extending through said elongated slot and adapted to move therealong as said switch blade is moved into and out of engagement with said discs, whereby said discs will be brought into good contact making engagement with the contact surfaces upon the opposite sides of said-stationary blade-like portion and said switch blade with a wiping action.

3. A full wiping contact for an electric switch, comprising a stationary terminal having an extending blade-like portion with contact surfaces on opposite sides thereof, said blade-like portion also having an elongated slot disposed adjacent and at one side of its contact making surfaces, a switch blade adapted to move relative to said blade-like portion having contact making surfaces on its opposite sides adapted to move into a position at the other side of said slot when said switch blade is in its closed circuit position, two

oppositely spaced discs disposed one on each side of said blade-like portion adapted to bridge the contact surfaces on the corrmponding sides of said blade-like portion and said switch blade, a supporting shaft for said spaced discs extending through said elongated slot and adapted to move therealong as said switch blade is moved into and out of cooperating relation with said stationary biade-likeportion, and spring means carried by said shaft for yieldingly holding said discs in good contact making engagement with the contact surfaces upon said blade-like portion and said switch blade, whereby said discs will be brought into engagement with the contact surfaces upon the opposite sides of said stationary blade-like portion of said switch blade with a wiping action when the switch blade is moved in its circuit closed position.

4. A terminal clip for an electric switch of the knife blade type, comprising an extending contact member having an elongated slot and contact surfaces adjacent thereto, a supporting shaft extending through said elongated slot transversely to the plane of said extending contact member, a pair of oppositely disposed discs mounted upon said shaft engaging opposite sides of said extending contact member and projecting outwardly in spaced parallel relation to provide a clip into which the end of a switch blade may be moved;

and means carried by said shaft for biasing said discs into good electrical contact with said extending contact member and the switch blade as the latter is moved into and out of engagement with said discs, whereby said discs will engage and disengage the contact surfaces upon said extending contact member and said switch blade with a rolling and transitional movement as the switch blade is moved into and out of engagement therewith. 1

5. Aterminal clip for an electric switch of the blade type, comprising an extending terminal forming member having an elongated slot and oppositely disposed contact making surfaces extending adjacent one side of said slot, a shaft extending through said elongated slot transverse to the plane of the contact making surfaces upon said terminal forming member, a pair of oppositely disposed current conducting members mounted upon said shaft engaging the opposite sides of said terminal forming member and projecting outwardly therefrom in spaced relation to provide a clip into which the end of a switch blade may be moved, and spring means carried by said shaft for biasing said current conducting members into good contact making engagement with the contact making surfaces upon said terminal forming member, the elongated slot in said terminal forming member being disposed along a line running substantially tangent to the arc of movement of the switch blade, whereby said shaft will move within said slot and said current conducting members will move into contact with the contact making surfaces upon said terminal forming member and the switch blade with a wiping action as said switch blade is moved into and out of engagement therewith.

6. In a full wiping contact for an electric switch, the combination of a pair of relatively movable current conducting members adapted to move into closely spaced cooperating relation with each other, each of said relatively movable members having contact forming surfaces arranged in a common plane on the sides thereof 7 and one of said members having an elongated slot located so as to be positioned between the contact forming surfaces upon said relatively movable members whensaid members are moved into cooperating relation, a shaftextending through said elongated slot and movable longitudinally therein, a pair of spaced discs upon said shaft each of which is adapted to engage corresponding sides of-said relatively movable current conducting members, and means for biasing said discs into good electrical contact with said contact making surfaces, whereby said discs will bridge the contact surfaces upon said relatively movable members and move with a transitional and a rotary movement into good wiping contact therewith when said members are brought into cooperating relation.

7. In a disconnecting switch, the combination of a stationary terminal forming member having a blade-like extension with raised contact surfaces on its opposite sides, a pivotally mounted 'sion having raised contact forming surfaces on its opposite sides, said blade-like extension also having an elongated slot formed therein and positioned so as to lie between the contact surfaces thereupon and the contact surfaces upon the switch blade when the switch blade is in its closed circuit position, a shaft extending through said slot transversely of said blade-like extension, a pair of spaced discs rotatably secured upon said shaft, securing means at the ends of said shaft, and spring means between each of said discs and the securing means at the corresponding end of said shaft for biasing said discs into good contact bridging engagement with the raised contact surfaces upon said blade-like extension and said switch blade.

8. In a disconnecting switch, the combination of a stationary terminal forming member having a blade-like extension with contact surfaces on its opposite sides, a pivotally mounted switch blade adapted to move into closely spaced cooperating relation with said blade-like extension having contact forming surfaces on its opposite sides, said blade-like extension also having an elongated slot formed therein and positioned to lie between the contact surfaces thereupon and the contact surfaces upon the switch blade when the switch blade is in its closed circuit position, a shaft extending through saidslot transversely of said blade-like extension, a pair of spaced discs mounted upon said shaft, securing means at the ends of said shaft, spring means between each ofsaid discs and the securing means at the corresponding end of said shaft for biasing said discs into good contact making engagement with the contact surface upon said blade-like extension and said switch blade, whereby said shaft will move longitudinally in said slot and said discs will rotate into wiping engagement with said contact surfaces, and a disposed contact surfaces adapted to move into closely spaced overhanging relation with saidblade-like extension, said blade-like extension also having a diagonally disposed slot formed at its end and positioned to lie between the contact surfaces thereupon and the contact surfaces upon the depending end of the switch blade, a shaft extending through said slot transversely of said blade-like extension, a pair of spaced discs rotatably secured upon said shaft, securing means at the ends of said shaft, pressure exerting means between each of said discs and the securing means at the corresponding end of said 1 shaft for biasing said discs into good contact making engagement with the contact surfaces upon said blade-like extension and the depending end of said switch blade, and a stop adapted to be engaged by said switch blade, whereby said discs will be held in bridging relation with the contact surfaces upon said blade-like extension and said switch blade when the switch blade is in its closed circuit position.

EDWARD F. SIXTUS.