US2141846A - High tension switch - Google Patents

Description

A. C. SCHWAGER HIGH TENSION SWITCH Filed March 16, 1957 2 Sheets-Sheet l IN VEN TOR.

Aucusr C. SCHWAGER Dec. 27, 1938. A. c. SCHWAGER 2,141,345

HIGH mansion SWITCH Filed March 16, 1937 2 Sheets-Sheet 2 INVENTOR. A usus 7' C Sc'HwA GER PatentedDec. 27, 1938 PATENT OFFICE HIGH TENSION SWITCH August 0. Schwager, San Francisco, Calif., assignor to Pacific Electric Manufacturing Corporation, San Francisco, Calif., a corporation of California Application March 16, 1937, Serial No. 131,191

9 Claims.

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 efficient switch and operating means which is adapted for use in connection with either single or multiphase circuits, where it is necessary to in sectionalize a power transmission line or to open a branch circuit at the point of intersection with the main line, or for the protection of any other electrical equipment that may be operated from high voltage transmission lines.

Another object of the invention is to provide a switch and operating means therefor, which can be easily and positively operated under all conditions of use.

Another object of the invention is to provide a novel counterbalancing spring arrangement for an electric switch of the type employing a relatively long blade that moves in a vertical plane. Another object of the invention is to provide a stationary contact and moving switch blade of special construction, which will provide a high contact pressure between the contact and blade.

A further object of the invention is to provide an improved form of blade with contact pressure producing means, in which the blade forms a continuous conductor without joints therein.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims.

For a better understanding of the invention. reference should be had to the following specification, taken in connection with the accompanying drawings, wherein there is shown by way of illustration and not of limitation a preferredembodiment thereof.

In the drawings:

Figure 1 is a side elevation of a complete switch constructed in accordance with this invention,

Figure 2 is a fragmentary view partially in section, showing the details of construction of the switch blade operating means,

Figure 3 is a view similar to'Figure 2, showing the switch blade with its operating mechanism in the circuit open position,

Figure 4 is a partial fragmentary view looking down on Figure 2, with portions broken away to disclose details of construction,

of thev rotatable insulator stand I0.

Figure 5 is a View similar to Figure 4, showing the parts in a different position,

Figure 6 is a sectional View taken along line VI-VI of Figure 2, looking in direction of arrows, 5

Figure 7 is an enlarged sectional view taken along line VII-VII of Figure 9, looking in direction of arrows,

Figure 8 is a horizontal sectional view of the contact engaging end of the switch blade, show- 10 ing the blade in its unexpanded condition,

Figure 9 is a view similar to Figure 8, showing the contact engaging end of the switch blade in its expanded position between the jaws of a contact clip, and 15 Figure 10 is an enlarged sectional view taken along line XX of Figure 8, looking in direction of arrows.

For the purpose of describing the invention, there is shown in the drawings, a single pole 20 switch in which the pivotal point of the movable switch blade is disposed centrally over a rotatable insulator stand so that the switch blade may be operated between its circuit open and closed positions by rotation of the rotatable in- 25 sulator stand. While for the purpose of illustrating this invention there is shown only one switch, it is to be understood that any number of these switches may be combined and simultaneously operated for the purpose of interrupting 30 any number of phases in a multiphase transmission system.

insulator stand l4 there is a tie bar conductor 40 i6 which connects with a bearing forming member I'I through which extends a shaft carried by an insulator cap 3 at the top of the insulator stand Ill. The tie bar i6 is firmly mounted upon the insulator stand M by means of a clamp I9, 45'

and at its outer end it carries aline circuit terminal 20. In this manner the tie bar l6 serves to secure the bearing forming member I! in alignment with the bearing H at the lower end The bear- 50 ing forming member l'l also carries a horizontally disposed shaft 2| upon which there is journaled a switch blade carrying member 22. Supported by and extending outwardly from the switch blade carrying member 22 there is a tu 65 'bular switch blade 23 that is adapted to cooperate with the stationary contact l5, as will hereinafter appear. To complete the circuit connections for the switch the stationary contact member I5 is provided with a line terminal 24. In addition to the line terminal 24 the stationary contact member also carries arcing horns 25 which extend upwardly and cooperate with an arcing horn 2B which is secured upon the tubular switch blade 23 so as to project outwardly beyond the end thereof. .In order to prevent, as far as possible, the circulation of current through the pivotal bearing of the switch blade carrying member 22 and the horizontally disposed shaft 2|, there is provided a low resistance jumper 21. For the purpose of operating the switch the rotatable insulator stand is provided at its lower end with an operating arm 28, a d at its upper end it is provided with a crank 2 which is connected by means of a beveleddinl: 30 with a radially dispo ed stub shaft 3| upon the switch blade carrying member 22.

Upon referring to Figures 2 and 3 of the drawings, it will be seen that the insulator ca-p l8 has a shaft portion 32 which is journaled in the bearing forming member I! by roller bearings 33. It will also be seen that the switch blade operating crank 29 is formed as an integral part of the shaft 32 so that when the rotatable insulator stand I is turned upon its bearing H, the crank 29 will move through an arc corresponding to the'movement of the rotatable insulator stand l0, and that as a result of the beveled link 30 the switch blade carrying member 22 will be caused to move in a vertical arc about the horizontally disposed shaft 2|.

For a better understanding of this form of switch blade operating means, reference should be had to Patent No. 1,965,272, granted July 3, 1934,

to Roy Wilkins, and assigned to the assignee hereof. In the aforesaid Letters Patent there ispro- 'vided. a counterbalancing weight-for the switch blade, whereas in accordance with the present invention the switch blade 23 is counterbalanced in a new and novel manner by a helical spring 34 which, as shown, is enclosed within a cylindrical housing 35 formed upon the switch blade carrying member 22. One end of the helical spring 34 engages a pin 36 carried by the bearing supporting member l1, and at its other end it engages the underside of the cylindrical housing 35 so as to exert a circuit opening bias upon the switch blade carrying member 22, the amount of this bias being determined by the initial torsion in. the spring 34 at the time of assembly. As shown, the cylindrical housing 35 is so arranged that it will cooperate with a web 31 formed upon the bearing supporting member I! and provide a protective covering for the switch blade operating mechanism. Further details of the construction and arrangement of the helical spring 34 are shown in Figures 4 and 6 of the drawings. In this 'latter figure .of, the drawings it will be seen that the horizontally dis-- posed shaft 2| is pinned between ears 33 and 33 arranged at each side of the web 31 'upon the bearing forming member H, the car 33 being extended out so as to form an end plate 43 for closing the cylindrical housing 35 at this end. This figure of the drawings also shows the switch blade carrylng member 22 as journaled upon the hori-, zontally disposed shaft 2| by means of a roller bearing 4|.

As a further feature of the presentinvention, the switch blade -23 is of a novel construction in that it provides for the establishment of a high pressure contact between it and the stationary contact l5, as will be hereinafter pointed out. In connection with this feature of the present invention, it is necessary that means be provided to effect an operation of this high contact pressure producing mechanism at the contact end of the switch blade.

As illustrated in Figures 1, 2, 3, 4 and of the drawings, this contact pressure producing mechanism is arranged to be operated by a crank arm 42 which is also carried by the insulator cap I8. As shown, the crank arm 42 carries a roller 43 which is adapted to engage a cam member 44 that is pivotally mounted upon a stub shaft 45 upon the switch blade carrying member 22. As better shown in Figures 4 and 5 of the drawings, the cam member 44 is mounted so that it is located in trailing relation with the stub shaft 45, and near its outer free end it is connected by means of a clevis 46 to an operating rod 41 which extends outwardly through the tubular switch blade 23 to the high contact pressure producing mechanism, which will be presently described in detail.

With the cam member 44 pivotally mounted, as described, in trailing relation with its pivotal axis upon the stub shaft 45, it will be seen that it will always be in proper alignment with the roller 43 upon the crank arm 42 when the parts are brought into cooperating relation. The pivotally mounted cam member 44 has a downwardly extending flange 48 upon which the ,roller 43 is adapted to roll, and for-the purpose of insuring a release of the high pressure contact mechanism "upon an opening of the switch, the pivotally mounted cam member 44 also has a complementary opposed cam surface 49 which, in cooperation with the roller 43, effects a positive return of the cam 44 and the operating rod 41 to its initial position, as shown in Figure 5 of the drawings.

Reference will now be made to Figures 7, 8, 9 and 10 of the drawings, for a detailed description of the high contact pressure producing aspects of the present invention. As shown in Figure 'I of the drawings, the stationary contact member II has two upstanding opposed contact forming surfaces 50 and 5| between which the end of the tubular switch blade 23 is adapted to engage. The contact forming surfaces 50 and 5| are here shown as held in fixed spaced relation by means of a threaded tie rod 52. This figure of the drawings also shows the tubular switch blade 23 as being split in a vertical plane through its center, as indicated at the points 53, so that the halves of the switch blade 23 at each side of the split 53 may be expanded outwardly and into high pressure engagement with the opposed contact forming surfaces 50 and 5| of the stationary contact l5. The split 53 only extends into the end of the switch blade 23 sumciently far to provide for the necessary expansion required, and at the inner end of the split 53 there is a clamping collar 54 which will prevent a further splitting of the blade at this point. The collar 54 also serves as a securing means for the arcinghorn 28 which is carried by the blade 23.

In order to preclude the formation of high resistance oxides upon the contact surfaces 53 and 5| and upon the contact engaging surfaces of. the tubular switch blade 23, these contact forming surfaces are provided with a silver plating or silver inserts which are made as an integral \part of the contact surfaces. As shown in Figures "8, 9 and 10 of the drawings, there are disposed within the tubular switch blade, in proper cooperating relation with the split end thereof,

spaced supports 55, 56 and 51, which carry oppositely positioned spring bars 58 and 59 that extend parallel and at opposite sides of the split 53 in the end of the switch blade 23. The support 55 is of a continuous annular form so that the spring bars 58 and 59 at this end will be held against outward movement, whereas the supports 58 and 5'! are independent of each other and permit the outer ends of the spring bars 58 and 59 to move outwardly, as will hereinafter appear. The spring bars 58 and 59 are held at one end upon the support 55 by means of a pin 58 and a spacing collar 6!, and at their other ends they are secured respectively upon the supports 56 and 5'5 by a similar free floating pin 62 and a spacing collar '63. The spacing collar 93 is also shown as having an extension 54 into which a stud 85 is threaded. The stud 85, as will be clear from these figures of the drawings, serves through the medium of the compression spring 88 to yieldingly hold an end closure cap 81 upon the open end of the tubular switch blade 23. The closure cap 81 has inwardly projecting lugs 58 which center it upon the switch blade 23. Disposed in operative relation between the spring bars 58 and 59 there is an ofi-center link or toggle mechanism, by means of 'which a pressure may be exerted intermediate their ends to exert an outward expanding force within the split end of the switch blade 23 to bring the halves thereof into high pressure engagement with the opposed contact surfaces 58 and 5i upon the contact member l5. As illustrated, this off-center or toggle mechanism comprises, as ismore clearly shown in Figure 10 of the drawings, a pair of spaced diagonally disposed links 59 which are pivotally secured approximately at the middle of the spring bar 59 by means of a strut 10 upon the end of which there is secured a pin ll about which the links 59 pivot. Between the free ends of the links 69 there is a clevis-like member 12 to which the operating rod 41 is connected, and between the forked end of this clevis-like member 82 there is a roller I3 which is adapted to roll into pressure exerting engagement with the opposite spring bar 58. The operating rod 4! is adapted to be'threaded' into the end of the clevis-like member '12, and at this end the member i2 also has a yoke-like construction which extends around the floating pin 60 and the spring bar spacing collar 6| so that it may move longitudinally with respect thereto. Extending downwardly at the roller supporting end of the clevislike member 72 there is a stop member M that is adapted to engage the spring bar 59, as shown in Figure 8 of the drawings, when the pressure producing toggle mechanism is inoperative, and to engage the shaft H, as shown in Figure 9 of the drawings, when the toggle mechanism is in its fully operative position. At this point it should be noted that when the toggle mechanism is in its released or inoperative position, the

roller I3 will be off-center with respect to the pivotal point Ii of the links 59 and that by virtue of the stop 14 the pivotally mounted cam 44 will be held by the two opposed spring bars 58 and 59 in the position shown in Figure 4 of the drawings. It will also be noted that when the 'toggle mechanism is in its operative position, as

shown in Figure 9 of the drawings, the roller I3 will again be in an off-center position with re-- of the drawings.

As shown in Figure 9 of the drawings, it will be noted that the spring bars 58 and 59 have been bowed out considerably, while at the same time the switch blade 23 has not been spread to any noticeable extent. However, in spite of the ab-- sence of a spreading in the switch blade 23, it will be understood that the pressure which is stored up in the bowed spring bars 58 and 59 is being exerted through the sides of the switch blade, so as to create a high contact'pressure with the opposed contact surfaces 59 and 5| of sure contact with the contact surfaces 50 and 5i.'

The operation of the switch and the contact pressure producing means contemplated by this invention is as follows:

When the switch is in its closed circuit position, as shown in Figure 1 of the drawings, and the rotatable insulator stand H! is turned in the direction indicated by the arrow'thereupon, the

end of the crank arm 29, as shown in Figure 2 of the drawings, will move away from the observer and displace the link-30 out of the plane which intersects the axes of the insulator stand -l0 and the pins at its ends. During this movement of the crank arm 29 the helical spring 35 will cause the switch blade carrying member 22 to rotate ina clockwise direction, assisted by the crank arm 29 as it continues to move in the direction indicated, until the switch blade carrying member and its switch blade 23 has assumed the position indicated in Figure 3 of the drawings.

The above describes the opening operation of the switch. Now, when the rotatable insulator stand I8 is turned in the opposite direction, the crank arm 29 will be moved back into the position illustrated in Figure 2 of the drawings, and in doing so, it will exert a pulling force upon the beveled link 38 to recoil the helical spring 59 and bring the switch blade 23 into its contact engaging position; As the end of the switch blade 23 approaches its final position upon the stationary contact I5, the parts of the contact pressure producing means will be in the positions illustrated in Figure 8 of the drawings, and the pivotally mounted operating cam 45 will be in the position illustrated in Figure 5 of the drawings. As the crank arm29 now continues to move into its final position, the cam engaging roller 53 upon the crank arm 42 which extends oppositely,

.will engage the cam 44, as illustrated in Figure 5 of the drawings, and as the insulator stand Ill continues to rotate, the roller 43 will move the cam 44 into the position illustrated in Figure 4 This movement of the cam dd will exert an operating force through the rod 5? which extends through the tubular switch blade 23 and cause the toggle mechanism, which includes the roller 13, to assume the position illustrated in Figure 9 of the drawings. During this latter operation of the cam 44 it wlll be understood that the end of the switch blade 23 will have reached its final position between the opposed contact surfaces 50 and 5! upon the stationary contact I, and as a result an excessive spreading at the split end of the switch blade 23 will be prevented by these opposed contact surfaces. However, as the toggle mechanism is brought into its final operative position, the spring bars 58 and 59 will be bowed outwardly, as indicated, and thus exert an expanding and a contact pressure producing force at the inside of the tubular blade 23 adjacent the opposed contact surfaces 50 'and' SI. With this arrangement it will be seen that because of the nature of the spring bars 58 and 59 there is provided a continuing application of a pressure producing force which is wholly dissimilar to any of the contact pressure producing means used heretofore, as for example, where the contact pressure producing force is exerted between fixed surfaces and produces a strain upon the parts rather than upon a yielding pressure storing means, as is provided by this invention.

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 a specific device-and arrangement, I desire to have it understood that this invention is not ered as part of this invention.

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

1. In a switch of the character described, the combination of a switch blade pivotally mounted at one end upon a suitable support and having an expandible end, a contact having opposed stationary contact forming surfaces between which the expandible end of said switch blade is adapted to move, expanding means at the contact engaging end of said switch blade adapted to expand the end thereof into high pressure contact with the opposed stationary surfaces of said contact, an operating member pivotally mounted intermediate the ends of said switch blade and movable with the switch blade in an arc about the pivotal axis of the switch blade, a rod forming an operating connection from said member to the expanding means at the end of the switch blade, a rotatable shaft for imparting movement to said switch blade extending substantially at a rightangle to said switch blade when said switch blade is in its closed circuit position and having its axis intersecting the pivotal axis of said switch blade, and means carried by said rotatable shaft movable in an arc intersecting the arc of movement of the operating member upon the switch blade, said means being adapted to engage and move said operating member about its pivotal mounting upon the switch blade to transmit a blade expanding force through said rod to the expanding means at the end of the switch blade as the switch blade reaches its final closed circuit position between the opposed stationary contact forming surfaces of said contact.

2. In a switch of the character described, the combination of a rotatable insulator stand having a switch blade operating crank arm at, the upper end thereof, a stationary support forming member upon which. the upper end of said insulator stand is journalled, a horizontally disposed shaft upon said stationary support extending transversely to and intersecting the axis of said rotatable insulator stand, a switch blade mounted for movement in a vertical plane upon said horizontally disposed shaft, 9. link connecting the end of said crank arm with said switch blade, whereby said switch blade will be moved in a vertical plane about said horizontal shaft as said insulator stand is rotated about its vertical axis, a switch contact having opposed stationary faces between which said switch blade is adapted to move, said switch blade having contact forming surfaces adapted to be expanded into contact with the opposed stationary surfaces of said switch contact, means at the end of said switch blade for expanding its contact forming surfaces into high pressure contact with the opposed stationary surfaces of said switch contact, means carried by and movable with said switch blade including an operating rod connecting with the expanding means at the end of said switch blade, and a radially extending arm movable with said rotatable insulator stand adapted to engage said means upon the switch blade and move said operating rod to expand the contact forming surfaces of said switch blade into high pressure contact with the opposed stationary surfaces of said switch contact when the switch blade has moved into its final closed circuit position upon said switch con tact.

3. In a switch of the character described, the combination of a rotatable insulator stand having a switch blade operating crank arm at the upper end thereof, a non-rotatable bearing forming member, mounted at the upper end of said insulator stand having a horizontally disposed shaft extending transverse to the axis of said rotatable insulator stand, a tubular switch blade mounted for movement in a vertical plane upon said horizontally disposed shaft, a link connecting the end of said crank arm with said switch blade, whereby said switch blade will be moved about said horizontal shaft as said insulator stand is rotated about its axis, a second insulator stand secured in spaced relation with said rotatable insulator stand, a switch contact carried by said second insulator stand having opposed faces between which said switch blade is adapted to move, said switch blade having contact forming surfaces adapted to be expanded into contact with the opposed surfaces of said switch contact, means.

within said tubular switch blade for expanding the end thereof, a pivotally mounted cam member carried by said switch blade having an operating rod connected with said switch blade expanding means, and a cam engaging roller carried by said rotatable insulator stand adapted to engage and move said cam to expand the end of said switch blade between the opposed surfaces of said switch contact when said switch blade has been moved into its circuit closing position with respect to said switch contact.

4. In a switch of the character described, the combination of a rotatable insulator stand having a switch blade operating crank arm at the upper end thereof, a non-rotatable bearing forming member mounted at the upper end of said in'sulator stand having a horizontally disposed shaft extending transverse to the axis of said rotatable insulator stand, a switch blade -mounted for movement in a vertical plane upon said horizontally disposed shaft, a link connecting the end of said crank arm with said switchblade, whereby said switch blade will be moved about said horizontal shaft as saidv insulator stand is rotated about its axis, a second insulator stand secured in spaced relation withsaid rotatable insulator stand, a switch contact carried by said second insulator stand having opposed faces between which said switch blade is adapted to move, said switch blade having a split end forming movable contact surfaces adapted to be expanded into contact with the opposed surfaces of said switch contact, means at the split end of said, switch blade for expanding the split portionthereof, a pivotally mounted cam member carried by said switch blade a'djacent its pivoted end having an operating rod connected with said switch blade expanding means, and a cam engaging roller carried by said rotatable insulator stand adapted to engage and move said cam and said operating rod to expand the split end of said blade between the opposed surfaces of said switch contact when said switch blade has been moved into its circuit closing position with respect to said switch con tact.

5. In a switch of the character described, the combination of arotatable insulator stand having a switch blade operating crank arm at the upper end thereof, a non-rotatable bearing forming member mounted at the upper end of said insulator stand having a horizontally disposed shaft extending "transverse to the axis of said rotatable insulator stand, a switch blade carrying member 'mounted for movement in a vertical plane upon said horizontally disposed shaft, a link connecting the end of said crank arm with said switch blade carrying member, whereby said switch blade carrying member will be moved about said horizontal shaft as said insulator stand, is rotated about its axis, a second insulator stand secured in spaced relation with saidrotatable insulator stand, a switch contact carried by said second insulatdr stand having opposed faces between which a switch'blade is adapted to move, a switch blade carried by said switch blade supporting member having I contact forming surfaces adapted .to be expanded into contact with the opposed surfaces of said switch contact, means carried by the switch blade for producing an expansion at the end thereof, a cam member carried by said switch blade supporting member having an operating rod connected with said switch 1 blade expanding means, and a cam engaging roller carried by said rotatable insulator stand adapted to engage and move said cam and said operating rod to expand the end of said blade between the opposed surfaces of said switch contact when said switch blade has been moved into its circuit closing position with respect to said switch contact.

6. In a switch of the character described, the combination of a stationary contact having rigid opposed contact forming surfaces between which a switch blade is adapted to'engage, a tubular switch blade pivotally mounted to cooperate with said stationary contact and having its end split along its central axis, a pair of spaced supports secured within said tubular switch blade adjacent the split end thereof, the outer one of said supports being in two parts, one at each side of the split in the switch blade, a pair of spring steel bars extending between said supports parallel with the plane of the split in said switch blade, means disposed between said spring bars adapted to exert a force upon said spring bars to expand the split end of said switch blade, an operating rod connected with said means and extending to the pivoted end of said switch blade, and means at the pivotal end of said switch blade adapted to move said operating rod in an operating direction when the switch blade is in its closed circuit position to establish a high pressure engagement between the opposed surfaces of said stationary contact and the split end of said tubular switch blade.

7. In a swit' b of the character described, the combination or a stationary contact having opposed contact forming surfaces between which a switch blade is adapted to engage, a tubular switch blade pivotally mounted to cooperate with said stationary contact and having its end split along its central axis, switch operating means for moving said switch blade about its pivot, a pair of spaced supports carried by said tubular switch blade within the split end thereof, the outer one of said supports being in two parts, one at each side of the split in the switch blade, a pair of spring steel bars extending between said supports normally parallel with the centerof the tubular switch blade, a toggle, means disposed between said spring bars adapted to exert a spreading force upon said spring bars to expand the split end of the switch blade transverse to the plane of the split therein, a toggle operating means extending through the tubular switch blade to its pivoted end, and means carried by said switch operating means cooperating with said toggle,

operating means when the switch blade is in its closed circuit position to operate said toggle means and establish a high pressure engagement between the opposed surfaces of said stationary contact and the split end of said switch blade.

8. In a switch of the character described, the combination of a stationary contact having rigid opposed contact forming surfaces between which a switch blade is adapted to engage, a tubular switch blade pivotally mounted to cooperate with said stationary contact and having its end split along its central axis in a vertical plane, a pair of spaced spring bars disposed within the split end, of the switch blade and extending parallel with the plane of the split in said switch blade, the ends of said spring bars nearest the pivoted end of said switch blade being held against a spreading movement and the outer ends of said bars being free to spread and exert an expanding force within the switch blade to spread the split end thereof, and means disposed between said spring bars intermediate their ends operable by a rod extending through the tubular switch blade toits pivoted end adapted to exert a spreading force upon said spring'bars to expand the-splitend of the switch blade into high pressure engagement with the opposed surfaces of said stationary contact.

9. In a switch blade for an electric switch of the character described, the combination of a tubular blade forming member pivotally mount- -ed at one end and having its free end split to provide for a spreading thereof, pin supporting members secured to the inside of said blade member at each side of the split therethrough, a free floating pin mounted in said members and permitting movement of the sides of said blade, 9.

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