US1275326A - Air-break switch. - Google Patents

Description

l. R. TOWNSEND.

AIR BREAK SWITCH.

APPLICATION FILED NOV. 26. I915.

1,275,326. Patented Aug. 13, 191%;

2 SHEETSSHEET 1.

J. R. TOWNSEND.

AIR BREAK SWITCH.

APPLICATION FILED NOV. 26. Hi5.

1,275,326. Patehted Aug.13, 191&

2 SHEETS-SHEET 2.

Hllui Mill] NIIIHIHiHHfllmumm OFFICE],

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Application flied November 26, 1815. Serial No. 88,688. v

To all whom it may concern:

Be it known that I, Jomv R. TowNsnNn, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and use ful Improvements in Air-Break Switches, of

i which the following is a specification.

My invention relates to air-break switches, and refers particularly to switches which :are used for openin the circuits of hightenslon transmission mes.

The air-break switches of the class to which my invention belongs are ordinarily mounted on the tops of poles or towers, which carry the transmission lines. In the. usual -3-phase system three conductors lead to an air-break switch and three conductors lead from this switch, the switch itself having three sets of contacts which serve 'to bridge the respective conductors and make electrical connection therebetween. As the current transmitted over a high-tension system is often in excess of 60,000 volts, it will be apparent that unusual precautions must be taken in connection with the construction of air-break switches to prevent destructive and dangerous arcing when the switch is opened, thereby interrupting the circuit.

It is the ob ect of my invention to open a high-tension circuit quickly and surely without the formation of a destructive arc and without danger of enabling the current to strike from one of the parallel conductors or phases to another, thus causing shortcircuiting of the system.

It is a further object of my invention to provide auxiliary contacts, which remain in engagement with each other after the main contacts have been separated from each other, so that all of the arcing will take place at the auxiliary contacts, which are of relatively cheap material, and which, owing to the construction of my improved switch, are quickly separated from each'other by a wide gap on opening of the switch, thereby causing the rapid and certain breaking of the are.

A still further object of my invention resides in constructing the two operating halves of the switch so that the parts rotate in a vertical plane and in opposite directions at the same rate of speed, mechanism also being provided so that abrupt and sudden movement'of the switch at or near its closed and full open positions is avoided, thus doing away with danger of injuring the Specification of Letter! we. Pate ted 13, 1918.

switch on account of careless handling under the. stress of excitement or for other cause.

A still further object of my invention resides in the provision of a protector for the that the operation of the main contacts so latter may not be interfered with by accumulations of sleet or ice on the contacts. The protector is so constructed that it serves to cover the contacts when theilatter are both in closed and open positions.

A still further ob]ect of my invention resides in the means for connecting the switch with the conductors which it serves to bridge so that there is no possibility of any loose or flexible conductor coming in contact with a grounded framework or other insulated parts, which might cause injury to life or property.

These and other advantages of my invention will be more readily understood by reference to the accompanying drawings, in which- Figure 1 is an end elevation of my improved switch, showing its operating mechanism connected therewith;

Fig. 2 is a plan of the switch shownv in Fig. 1;

Fig. 3 is a fragmentary sectional view taken on the line 33 of Fig. 2, and showin the drag link used to connect the two si es of the switch;

Fig. 4 is a vertical section throu h one of the cross-pieces, showing one of t e toggle guides attached thereto;

Fig. 5 is an enlarged section through the auxiliary contacts, showing a plan of the contact guide; and

Fig. 6 is an enlarged plan of the main contacts and sleet protector, a portion of the latter being broken away.

In Fig. 2 I have shown my improved switch as constructed for a 3-wire system, the conductors 10 leading to the insulators 11, which, in turn, are anchored to the stringers 12. Although I have shown three pairs of conductors, it will be evident that braced by means of the cross-braces 15. Resting on the stringers 12 are the channel irons 16, which are provided at their ends with the bearings 17, which serve to support the two shafts 18. These shafts extend the entire len th of the stringers 12.

On each of the shafts 18 is mounted the insulator support 19 carrying a petticoat 1nsulator 20. Each of the insulators 20 carries at its outer end the bracket 21, which, in turn, carries the contact rod 22, of copper, brass, or other suitable conductmg material. As most clearly shown in Fig. 6,one of the contact rods 22 has attached thereto the contact blade 23, whereas the opposite contact rod 22 carries the spring contacts 24, 24, between which the contact blade 23 is adapted to be inserted and form snug contact therewith. By using the form of contacts which 'I have just mentioned severe jar is avoided when the contact blade 23 is brought into connection with the spring contacts24.

Each of the contact rods 22 has a flexible steel auxiliary contact 25 attached thereto, one of these auxiliary contacts carrying near its upper end the guiding V 26, by means of which electrical connection between the two auxiliary contacts 25, 25 is insured when the switch is in closed position.

A link 27 is pivotally connected to the outer end of each of the contact rods 22, and is, in turn, connected at its outer end with a link 28 which has its opposite end ivotally attached to the bracket 29 carried by the conductor 10.

As clearly shown in Figs. 1 and 6, the contact blade 23 and the spring contacts 24 are protected, respectively, by the housing 30 closed at its top and sides. When the switch is in closed position, as indicated in full lines in Fig. 1, the two housings 30 are brought into contact with each other and form a tight joint on their inner ends so that the main contacts, consisting of the blades 23 and the spring contacts 24, are effectually protected from the action of snow, sleet, rain, or the like. In order to carry off water the housings 30 on their tops preferably slope slightly from their inner to their outer edges. Each of the housings 30 is pivotally connected to the corresponding contact rod 22 by engagement of the screws 31 with the cross-member 32 carried by the end of the contact rod 22. A link 33 serves to connect each of the housings 30 with a bracket 34, which is pivotally mounted on the link 27.

In order to provide electrical connection between each air of conductors 10 in the same line, eac of the links 28 is connected with the corresponding conductor 10 through the flexible conductor 35, which, on one end, is suitably connected to the conthe conductor 37 connects the link 27 with I the contact rod 22.

I will next pass to a description of the actuating mechanism for the switch. This actuating mechanism is preferably located near one of the oles 14, as clearly shown in Figs. 1 and 2. The arms 38, rigidly mountedon the shafts 18, are'connected by the toggle 39, which consists of the two rods 40 pivotally connected with each other at 41.

hese two rods 40 operate within the guides 42, which are suitably attached to one of the channel irons 16, as clearly shown in Figs. 2 and 4. A drag link 43 having the pivotally connected arms 44 mounted on the shafts 18 serves to insure that on rotation of one of the shafts 18 in one direction the other shaft will be rotated in the opposite direction at'the same rate of speed.

Pivotally' connected to the toggle 39 at the pivotal polnt 41 is the link 45, which leads to the end of the arm 46 of the bell crank lever 47, which is pivotally mounted at the point 48 on the prate 49, which is carried by the pole 14. othe arm 50 of the bell crank lever 47 is attached the link 51, and to the arm 52 is attached the link 53. The lowerends of the links 51 and 53 are attached to the respective ends of the lever 54 pivotally mounted at 55 on the plate 56 carried by the pole 14. Each of the links 51 and 53 preferably has therein an insulating section '57 to act as a safeguard to prevent the passage of high-tension current to the o crating handle, which will next be.

descri ed. The operating handle 58 is attached to the lever 54, and when this operating handle is swung from the position in dicated in full lines in Fig. 1 to the position indicated in dotted lines, the lever 54 is rotated on its pivot 55 into the position shown in dotted lines. The pole 14 carries a crossarm 59 so that when the operating handle 58 is swung from one osition to another a staple, or similar device, may be inserted through the aperture 60 in the handle 58 and passed into the cross-arm 59 so that the handle 58 will be held in the position to which it has been moved.

Having thus described the various parts which are used in connection with my 'improved switch, the operation of the same may now be readily understood:

When the switch is in closed position the various parts are as shown in full lines in Fig. 1'. The current passesfrom one of the main conductors 10 through the flexible conductor 35, thence'throu h the link 28. flexible conductor 36, link 2 flexible conductor 37, and contact rod 22, through the contact blade 23 and spring contacts 24, to the opposite contact rod 22, flexible conductor 37, link 27, flexible conductor 36, link 28, and flexible conductor 35, to'the main conductor 10 on the side of the switch opposite to the conductor 10 first mentioned. It will thus be evident that the circuit between the conductors 10 of the same line is thus closed. When it is desired to open the switch, the handle 58 is moved to the position shown in dotted lines in Fig. 1. Through the instrumentalit of the lever 54 and the links 51 and 53, the bell crank lever 47 is moved into the position shown in dotted lines, so that the arm 46 is brought into engagement with the stop 61, the arm 52 having been in engagement with the stop 62 when the bell crank lever was in the position indicated in full lines. As the movement of the handle 58 and the bell crank lever 47 begins to take place, the link 45 is moved upwardly, and causes the pivotal point 41 of the toggle 39 to be carried upwardly until the link 45 and the arm 46 are brought into the same axis. This toggle 39 causes the arms 38 to be moved inwardly so that the shafts 18 are rotated in opposite directions. It will be evident that as the pivotal point 41 of the toggle 39 first begins to move upwardly the movement communicated through the arms 38 to the shafts 18 will be relatively slow, but will become more rapid as the two rods 40 of the toggle become disposed at a more acute angle to each other. On the other hand, as the arm 46 of the bell crank lever 47 approaches its vertical position, and thereby a dead center, the upper end of the link 45, and, therefore, the pivotal point 41, will travel upwardly at a slower rate (as sumin a uniform rate of movement of the operating handle 58), this upward movement of the point 41 gradually decreasing in velocity until the link 45 and the arm 46 are brought into the same axis, whereu on further iotation of the shafts 18 stops. The gradual cessation of movement near the extreme open position of the switch, and a similar action taking place when the switch is closed, is a feature of great advantage, inasmuch as it effectually prevents undue strains caused by severe shoe s or jars which would otherwise take place if the switch were carelessly or unskilfully operated. According to the construction which I have just described, no matter how violently the operating handle 58 is moved from one extreme position to the other the switch itself is always opened or closed, as the case may be, without jar or shock.

As the shafts 18 are rotated in the manner just described, the movement of the two shafts is kept in synchronism b I the action of the drag link 43. The insul ators 20 are moved outwardly into the dotted positions. As this movement takes place the contact blade 23 is withdrawn from the spring contacts 24 so that the passage of current through these main contacts is interrupted. After the main contacts have been separated, however, the auxiliary spring contacts 25, which gradually straighten out as the insulators 20 are moved outwardly, are still maintained in contact with each other, so that the current passes from one contact rod 22 to the other through these auxiliary contacts 25. The engagement between t e two auxiliarycontacts 25 continues until the point 41' of the to gle 39 has traveled approximately one-third ofits total distance of travel .in a vertical plane. By this time the shafts 18 are rotating at a considerable and gradually increasing rate of speed. The upper ends of the auxiliar contacts 25 are now uickly separate from each other, and t e parts are thereafter brought into the position shown in dotted lines. It will be evident that the arc-breaking distance between the ends of the two auxiliary contacts 25 is very great in proportion to the movement of the switch as a whole, and an arc is thus quickly and effectively broken not only on account of the great distance by which the auxiliary contacts are separated from each other, but also on account of the fact that when the separation takes place the movement of the auxiliary contacts in opposite directions is very rapid.

As the switch is moved from closed to open position, it will be evident. that the link 33 pivotally attached to the protector casing 30 and to the link 27 willmaintain the protector 35 in position so that the latter covers the contact blade 23, or the spring contacts 24, as the case may be, when the 105 switch is in its full open position. In this way water, snow, sleet, and the like, are prevented from accumulating on the switch lade or spring contacts.

When it. is desired to close the switch the operating handle 58 is, of course, moved from the position shown in dotted lines to that shown in full lines in Fig. 1. The auxiliary contacts 25 first engage each other so that any arcing which results takes place at these auxiliary contacts. The contact blade 23 is thereafter brought into en agement with the spring contacts 24, and the normal passage of current, as previously described, takes place. The engagement of the contact blade 23 with the spring contacts 24 is very efiicient, while at the same time there is no violent shock or jar connected with this operation. This feature, taken in con'unctionwith the gradual decrease inthe rapidity of rotation of the shafts 18 as the full open and full closed positions of the switch are approached, greatly relieves the strain on the insulators 20, and I have found by practical experience that the breakage of. 130

'or sense of my invention, as defined in the ap en ed claims.

hat I claim is: 1. In an electric switch, the combination of a pair of main contact members adapted said housings in rotecting position above said engaging en s during rotation of said shafts in moving said switch from closed to open) osition.

5. u an electric switch, the combination of a pair of parallel shafts, a contact memto engage each other, means for separating said contact members from each other, a air of-anxiliary spring contact mmbers eac of which is carried by one of said main contact members, said auxiliary contact members adapted to engage each other during the engagement of said main contact members and to be separated from each other only after said main contact members have been separated from each other, and'a V-shaped guiding member carried by. one of said auxiliary contact members, whereby the engagement of the other auxiliary contact member with said first-mentioned auxiliary contact member is insured.

2. In an electric switch, the combination of a shaft, means for rotatin said shaft, an insulator carried by said s aft, a contact member carried by said insulator, said contact member having an end adapted to engage a companion contact member, a protector housing carried by and above the engaging end of said contact member, and means for maintaining said housing'm covering position above said end (1111:1118 rotation of said shaft in moving said switch ,from closed to open position, whereby said end is covered in every position at all times.

3. In an electric switch, the combina tion of a shaft, means for rotatin said shaft, an insulator carried by said she a contact member carried by sald insulator, said contact member having an end adapted to engage a companion contact mem er, a link ivotally connected with said contact memer, a rotector housing above theengaging end 0 said contact member and pivotally connected thereto, and means extending from said housing to said link for maintaining said housing in position above said engaging end of said contact member during rotation of said shaft in moving said switc from closed to open position.

4. In an electric switch, the combination of a pair of parallel shafts, means for simultaneously rotating said shafts in opposite directions, an insulator carried by each of said shafts, a contact member carried by each of said insulators, said contact members having ends adapted to engage each other, a protector housing above each of said engaging ends and movable with said contact members, and means for maintaining ber carried by each of said shafts said contact members adapted to be brought into engagement with each other when said switch 1s m closed position, a protector housing carried by eac means for simultaneously rotating said shafts in opposite directions from one predetermined position of said shafts to another at a rate of speed gradually increasing from the startin point to substantially the midpoint of t e path of travel of said shafts and at a rate of speed gradually decreasin from substantially the mid-point to the end of said path of travel.

6. In an electric switch, the combination of a pair of parallel shafts, a contact member carried by each of said shafts, said contact members adapted to be brought into engement with each other when said switch is in closed position, means for simultaneously rotating said shafts in opposite directions from one predetermined position of said shafts to another at a rate of speed adually increasing from the starting point to substantially the mid-point of the path of a pair of parallel'shafts, a contact member carried by each of said shafts, said contact members adapted to engage each other when said switch 1s in closed position, a toggle having a pair of arms pivotally connected with each other and forming a substantially straight line with each other when said switch is in closed position and means for moving the pivotal point of connection of said to gle arms, whereby said shafts will be rotate in opposite directions at a gradually increasing rate of'speed and said contact members will be separated from each other.

8. In an electric switch, the combination of a pair of parallel shafts, a contact member carried by each of said shafts, said contact members adapted to engage each other when said switch is in clos position, a toggle having a pair of arms pivotally connected with each other and formin a substantially strai ht line with eac other when said switc is in closed position, a bell crank lever, a link extending from the pivotal point of connection of said toggle arms to one arm of said bell crank lever, said arm and said link adapted to he brought intosubstantially a straight line when the of said contact members, and a switch is in open position, and means for actuating said bell crank lever.

9. In an electric switch, the combination of a pair of parallel shafts, a contact member carried by each of said shafts, said contact members adapted to enga e each other when said switch is in close position, a toggle having a pair of arms pivotally connected with each other and forming a substantially straight line with each other when said switch is in closed position, a bell crank lever, a link extending from the pivoted point of connection of said toggle arms to one arm of said bell crank lever, said arm and said link adapted to be brought into substantially a straight line when the switch is in open position, means for actuating said bell crank lever, and a drag link connecting said shafts, whereby the latter will be moved synchronously.

In witness whereof I hereunto subscribe my name this 23rd day of November, A. D.

JOHN R. TOWNSEND.

Corrections in Letters Patent No. 1,275,326.

It is hereby certified that in Letters Patent No. 1,275,326, granted August 13,

1918, upon the application of John R. Townsend, of Chicago, Illinois, for an improvement in Air-Break Switches, errors appear in the printed specification requiring correction as follows: Page '4, strike out lines 11 to 27 and 86 to 116,

comprising claims 1, 6, and 7; renumber claims 2, 3, 4, 5, 8, and 9 as I 2, 8, 4, 5, and 6; and that the said Letters Patent should be read with these corrections therein thatthe same mayconform to the record of the case in the Patent Office.

Signed and sealed this 8th day of October, A. 1)., 1918.

R. F. WHITEHEAD,

Acting Commission" of Patents.

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