US3244826A - Operating mechanism for high voltage switch - Google Patents

Description

April 5, 1966 .1. BERNATT OPERATING MECHANISM FOR HIGH VOLTAGE SWITCH Filed oct. so, 1965 5 Sheets-Sheet 1 April 5, 1966 .1. BERNATT OPERATING MECHANISM FOR HIGH VOLTAGE SWITCH Filed oct. so, 1955 5 Sheets-Sheet 2 @iw m Q um mw u mw W.

April 5, 1966 J. BERNATT OPERATING MECHANISM FOR HIGH VOLTAGE SWITCH 5 Sheets-Sheet 3 Filed Oct. 30, 1963 April 5, 1966 J. BERNATT 3,244,326

OPERATING MECHANISM FOR HIGH VOLTAGE SWITCH Filed oct. so, 196s 5 sheets-sheet 4 April 5, 1956 J. BERNATT 3,244,826

OPERATING MECHANISM FOR HIGH VOLTAGE SWITCH Filed OCt. 50, 1965 5 Sheets-Sheet 5 United States Patent O 3,244,326 @PERTHNG MECHANISM FR I-IlGH VLTAGE SWTCH .oseph Bernatt, Arlington Heights, lill., assignor to S @t C Electric Company, Chicago, Ill., a corporation of Delaware Filed Oct. Sill, 1963, Ser. No. 320,167 11 Claims. (Cl. 20d- 48) This invention relates, generally, to electric circuit makers land breakers and it has particular relation to operating mechanisms therefor. It constitutes an improvement over the construction shown in lohn l. Mikos application Serial No. 212,613, led Iuly 26, 1962, now Patent No. 3,194,928, issued July 13, 1965, and H. l. Barta U.S. Patent No. 2,978,558, issued April 4, 1961.

Among the objects of this invention are: To provide for operating conjointly the poles of a polyphase high voltage switch in a new and improved manner; to rotate conjointly and in opposite directions a pair of insulator stacks carrying switch blades forming a center break switch construction by means of a single link connected to each stack; to operate the links by a centrally located crank sha-ft; to provide for stopping the crank shaft in overcenter toggle locked positions slightly more than 180 apart; to rotate the crank shaft through a chain drive mechanism by an operator that can be controlled from a remote point; and to interconnect the crank shafts of the several poles of the polyphase switch for rotation about a common axis and in effect for rotation by a shaft extending Iat right angles to the planes containing the axes of rotation of the pairs of rotatable insulator stacks.

In the drawings:

FIG. 1 is a perspective view of a switch construction embodying the present invention, only one pole of the polyphase switch being shown together with the mounting structure for three poles.

FIG. 2 is a view in end elevation taken generally along the line 2 2 of FIG. 1.

FIG. 3 is a top plan view of one pole of the polyphase switch construction, the switch lbeing shown in the closed position by full lines and the particular construction shown being that for the intermediate pole.

FlG. 3A is a top plan view of the pedestal assembly for one of the stationary insulator stacks.

FIG. 3B is a sectional view, at an enlarged scale, taken generally along the line 3B 3B of FIG. 3A.

FlCG. 4 is ya View, in side elevation, of the lower portion of the construction shown in FIG. 3.

FIGS. 4A, 5, 6, 7, 8 and 10 are elevational and sectional views `taken generally along the lines 4A 4A, 5 5, 6 6, 7 7, 8 3 and '1d-1h respectively of FIG. 4.

FIG. 6A is a vertical `sectional View taken |generally along Athe line 6A 6A of FIG. 6.

FIG. 9 is a view showing certain details of construction oi' the chain drive mechanism.

FG. 11 is a side elevational view of the lower right portion of the center pole, shown in FIG. 1, to illustrate a different operating mechanism.

FlG. 12 is a view, in end elevation, of the construction shown in FIG. 11.

FIG. 13 is a horizontal plan view taken generally along the line 13 13 of FIG. 11.

Referring now particularly to FG. 1 of the drawings, it will be observed that the reference character 1 designates, generally, a polyphase high voltage switch structure. For illustrative purposes it is pointed out that the switch structure 1 may be arranged to operate on an alternating current electric power transmission system operating at a voltage of 230 kv. However, it will be understood that the switch structure 1 can be employed for ICC systems operating at other voltages with suitable modifications. While the switch structure 1 is intended to employ three poles for a three phase system, only one of the switch poles is shown, generally, at 2. The others, it will be understood, are duplicates of the pole 2. Each pole is arranged to be mounted on the upper side of an elongated structural support 3 each of which is mounted on the upper ends of upright structural supports 4 4 that extend upwardly from concrete piers 5 5. On the cen-ter upright structural support l there is mounted a switch operating mechanism 6 that may be either manually or remotely controlled. The switch operating mechanism 6 is arranged to drive a vertical shaft 7 for effecting conjoint operation of the several poles 2 forming the switch structure 1 in a manner to be described.

Each pole includes stationary insulator stacks iB S that are lmounted near the ends olf the respective structural support 3 and extend upwardly thereform. They are also shown in FIGS. 3 and 4. At their upper ends the stationary insulator stacks 8 8 carry line terminals 9 9 to which line conductors can be connected in accordance with conventional practice.

The lower end of each stationary insulator stack 8 is bolted to ya circular metallic mounting plate `10, FIG. 3A, which is welded to the upper end of a support pipe 11 that extends through the respective end of the elongated structural support 3. Adjacent the upper end of `the support pipe 11 it extends through and is welded to an upper rectangular support plate 12 the ends of which overlie the upper surfaces of top angle members 13 13 which rorm the upper corners of the structural support 3. The corners of the upper support plate 12 are individually adjustable as to elevation by hollow ladjustment plugs one of which is shown at 14 in FIG. 3B. Here it will be noted that each adjustment plug 14 is threaded in the respective corner of the upper support plate 1.2 from, the under side with the head bearing against the upper surface of the horizontal liange of the top angle member 13. This provides for individual adjustment of each corner of the upper support plate 12. A bolt 15 extends downwardly through an inverted cup shaped spacer 16, the hollow adjustment plug 14 and the horizontal flange of the `top angle member 13. After the proper `adjustment of the position of the upper support plate 12 has been made by the adjustment lugs 14, the bolts 15 are tightened.

lt is desirable that there be a corresponding adjustment for the lower end of the support pipe 11 as well as to provide for rigidly securing the associated stationary insulator stack 8 in position by taking advantage of the full depth of the box girder truss construction of the structural support 3. For this purpose a rectangular lower support plate 17, FIG. 4A, is bolted to the lower surfaces of the horizontal flanges of bottom angle members 18-18 and the lower end of the support pipe 11 projects downwardly through a clearance opening therein. Angle clips 19', preferably four, are Welded to the upper side of the lower support plate 17 in uniform angular spaced relation around the clearance opening and are arranged to receive adjusting studs Ztl provided with foot portions 21 between which the lower end of the support pipe 11 is securely clamped.

Intermediate the stationary insulator stacks 3 8 are rotatable insulator stacks 22 22. They are suitably journaled at their lower ends on the respective structural support 3. At their upper ends the rotatable insulator stacks 22 22 carry switch blades 23-23 that are arranged to form a center break switch structure. Also mounted at the upper ends of the rotatable insulator stacks 22 22 are mechanism housings 24 24 which enclose certain switch operating mechanisms as described in the Mikos application above referred to. Between the line terminals 9 9 and the mechanism housings 24 .message 24 are located circuit interrupters 25-25 that are arranged, as described in the Mikos application, to interrupt the circuit between the line terminals 9-9 prior to opening of the switch blades 23-231 Provision is made, as described hereinafter, for rotating the insulator stacks 22-22 and thereby the switch blades 23-23 in opposite directions. For example, as indicated by the arrows Zai-26, the switch blades 23-23 are arranged to be swung to the positions shown by broken lines in FIG. 3 toward the switch open position, the arrangement providing a center break switch construction.

For rotating each of the rotatable insulator stacks 22-22 they are provided with depending shafts, one of which is indicated at 27 in FIG. 5. FIG. 4 shows the arrangement of the shafts 27 and indicates that they are suitably journaled in the respective elongated structural support 3. It is desirable to limit the rotation of each of the rotatable insulator stacks 22 in the switch closed and the switch open position. Preferably the rotation from one extreme position to the other is 102 although it will be understood that other ranges can be employed. For limiting the rotation of each shaft 27 and thereby the respective rotatable insulator stack 22 and switch blade 23 carried thereby, a stop arm 28 is clamped to the shaft 27 as seen in FIG. 5. The distal end of the stop arm 2S is arranged to engage one or the other of stops 29-29 which are suitably secured at 30-30 to the re spective elongated structural support 3. It will be understood that the stop 29-29 can be differently located on the support 3 and the stop arm 28 located in a different position on the shaft 27 with the arrangement being such that the movement of the respective rotatable insulator stack 22 and the switch blade 23 is limited in the manner described. Preferably the stops 29--29 are constructed to function as shock absorbers to absorb the impact of the moving parts at the ends of the opening or closing strokes.

For rotating each depending shaft 27 from one extreme position to the other there is provided, as seen in FIG. 6, an operating arm 31 which is suitably clamped in place. At the distal end of the operating arm 31 there is located an upstanding stud 32 on which a clevis 33 is pivoted. As seen in FIG. 6A the clevis 33 is provided with a hearing sleeve 33a having a Ipress lit and is journaled on the stud 32. Beveled ends 33b--33b are arranged to receive O rings 33c-33c that seal lubricant within the bearing sleeve 33a and prevent the entrance of extraneous material. A similar sealed bearing construction is employed for like applications in the switch structure 1. FIG. 6 shows the manner in which the clevis 33 is pivotally connected to a fitting 34 that, in turn, is clamped to one end of a link 35 in the form of a section of pipe.

At its other end the link 35 is clamped to a fitting 36 which extends from an adjustable clevis assembly 37. At the other end of the adjustable clevis assembly 37 there is located a clevis 38 which, as shown in FIGS. 7 and 8, is pivotally mounted on a stud 38' that extends laterally from a crank arm 39. It will be observed that a link 35 is provided for operating each of the rotatable insulator stacks 22--22 and that the links are connected to crank arms 39 which extend in diametrically opposite directions from a crank shaft that is indicated, generally, at 40.

As pointed out, the crank shaft 40 is shown more clearly in FIG-S. 7 and 8 of the drawings and it will be understood that a similar crank shaft and link construction is provided for each pole 2 of the switch structure 1. The crank shaft 40 includes integrally formed end plates 41- 41 that are secured by bolts 42-42 to end plates 43-43. Shaft extensions or bearing spindles 44-44 extend from the end plates 43-43 and are journaled in bearings 45- 45 that are carried by bearing support plates 46--46 that are secured suitably to the outer sides of the respective elongated structural support 3.

As shown in FIGS. 1 Iand 12 intermediate shafts 47- 47, in the form of pipe sections, constitute endwise extensions of the shaft extensions or bearing spindles 44-44 that extend from opposite sides of the intermediate structural support 3. Connectors 48-48 serve to interconnect the adjacent ends of the intermediate shafts 47-47 and the shaft extensions or bearing spindles 4444. If desired, the connectors lil-48 can include flexible coupling members with some degree of adjustment to accommodate misalignment between .the inter-mediate shafts 47-47, to -avoid application of undue strain on the bearings 451-45, and to permit accurate synchronization of the operation of the three poles 2. It will be understood that the outer ends of the intermediate shafts 47-47 are similarly connected to shaft extensions or bearing spindles extending from crank shafts, duplicates of the crank shaft 40, and mounted on the -outboard structural supports 3. This construction in effect provides a single shaft that is common to the three poles 2 of the switch structure 1 with some degree of flexibility therein for the above reasons. The axis of rotation of this common shaft extends at right angles to the planes containing the .axes of rotation of the rotatable insulator stacks 22-22 of each pole 2. The manner in which a mechanical connection is provided between the switch operating mechanism `6 and the shaft that is common to the three poles 2 will be described presently.

It is desirable that provision be made for permitting rotation of the crank shaft 40 through slightly 1more than When such rotation takes place the crank arms 39 are rotated in diametrically opposite positions from their positions as seen in FIGS. 7 and 8. In order to permit this movement the crank shaft 40 is provided with radially offset portions 49-49 on opposite sides of the crank arms 39-39 in order to permit the links 35-35 to move to corresponding positions. It will be understood that the 180 movement of the crank shaft 40 corresponds to the 102 rotation of the rotatable insulator stacks 22-d 22 and switch blades 23--23 carried thereby. By suitably proportioning the operating mechanism it is possible to achieve these diiferent degrees of rotation `as will be understood readily.

It is desirable to limit the movement of `the crank shaft 40 slightly past the overcenter position in each extreme position for the purpose of providing a toggle locked -operating mechanism. In order to accomplish this with a high degree of accuracy a stop arm Slis formed integrally with the crank shaft 40 and extends radially therefrom for engaging one or the other of stops 52-52 that are carried by and extend upwardly from a horizontal plate 53 that is located along the lower side of the respective elongated structural support 3. When this arrangement is employed there is a relatively large movement of the crank shaft 40 for a relatively small endwise movement of the links 35--35 interconnecting the crank arms 39-39 and the rotatable insulator stacks 22-22. At one extreme position this facilitates resistance to opening movement incident to corrosion, icing and the like. At each end of the movement between open and closed position, .the toggle action causes the rotation of the insulator stacks 22-22 and switch blades 23-23 to be slowed down from an otherwise high intermediate speed. This reduces the stress incident to stopping the moving parts at the extreme positions. The toggle locked operating mechanism, including the crank shaft 40, provides for more positive latching of the mechanisms in the mechanism housings 24-24 and makes the operation less critical. Also in the extreme position corresponding to the closed position of the switch blades 23- -23 it facilitates the movement thereof into full contact engagement and overcoming resistance `to such movement at substantial mechanical advantage.

The details of construction of each of the poles 2 of the switch structure 1 are identical as described hereinbefore except for the common drive to the intermediate pole 2. For this purpose, as shown in FIG. 8, a driven sprocket 54 is interposed between the end plates 41 and 43 at one end of the crank shaft 40 and a sprocket housing 55 is provided for shielding it and a chain 56 that is trained thereover. For the other two poles 2, instead of the driven sprocket 54, a spacer is provided which -is merely a circular flat plate in order to permit standardization of parts for the several poles.

Referring now to FIG. 9, it will be observed that the chain 56 extends through flexible c-onduits `57--57 that communicate with one side of the sprocket housing A55. At the ends of the chain 56 adjustable links 58-58 are connected and they extend through the flexible conduits 5757 for connection to the ends of a chain 59 that is trained over a drive sprocket `60 which is located within a sprocket housing `61 that is mounted on one end of the intermediate structural support 3. The arrangement is also illustrated in FG. where it will be observed that the drive sprocket `60 Iis mounted on a shaft 62 that is suitably journaled on the structural support 3 and has mounted thereon a bevel gear 63 which meshes with la bevel gear 6d that is fast on the upper end of the vertical shaft 7 which extends from the switch operating mechanismo.

It will be understood that, on suitable operation of the switch operating mechanism 6, the vertical shaft 7 is rotated in one direction or the other for opening or closing the switch blades 23-23 of each of the poles `2.

FIGS. 11, 12 and 13 show an alternate construction that can be employed in lieu of the switch operating mechanism t6 and vertical rotatable shaft 7. Here it Will be observed that the shaft l62, previ-ously described, has been omitted and a longer shaft y67 has been substituted. It will be understood that the shaft `67 carries the drive sprocket 60 thereon for rotation herewith. At the outer end of the shaft 67 there is mounted .a radial arm 68 to which a clamp connector `69 is secured for connection to the upper end of 'a link 70 in the form of a length of pipe. The lower end of the link 70 is connected to a crank arm A71 that is arranged to be rotated by a switch operating mechanism that is indicated at 72. The switch operating mechanism '72 can 'be constructed las described in yJohn I. Mikos U.S. Patent No. 2,796,478, issued Iune 18, 1957, and arranged either for manual or remote operation. Since the switch operating mechanism 72 is arranged for direct connection to the radial arm `68 that is located to one side of the structural support 3, the switch operating mechanism 72 is located on the same side of the upright structural support it adjacent thereto.

The mechanism for rotating the rotatable insulator stacks 2222 of each pole is located within the respective box like elongated structural support 3. This makes it feasible to protect the moving parts, such as the stop arms 28, operating arms 31, links 35, crank arms 39, etc., from icing which would interfere and possibly prevent operation of the switch structure 1. For this purpose as seen in FIGS. l, 12 and 13, side ice shields 73a and 7312 are secured to the sides of the structural support 3 and top ice shields 74a and 74b overlie the upper side at locations providing protection against icing for the underlying moving parts. lt will be understood that each structural support 3 is provided with ice shields 73a, 7'3b, 74a and 74b although, for the sake of clarity, only one of the supports 3 in FIG. 1 is illustrated as being so protected.

It is desirable that means be provided for controlling the rotation of the common drive shaft which includes the intermediate shafts 47-47 and the crank shaft 40 in order that the operating sequence under the control of the mechanisms in the mechanism housing 24-24 can function to control the operation of the circuit interruptcrs -25 in the desired sequence with respect to the movement of the switch blades 23 23. Accordingly, as shown in FIG. 2 of the drawings, there is provided a control mechanism, indicated generally at 75, for this purpose which may be constructed as shown in the above identified Barta Patent No. 2,978,558.

While the toggle locked operating mechanism, which includes the crank shaft dii, has been described as particularly useful for rotating the two insulator stacks 22-22 and the associated switch blades 23-23 and operating the circuit interrupters 25-25, it will be understood that it can be employed for operating less than all of these elements. For example, one of the circuit interrupters 25 can be omitted while still using the two switch blades 23-23 operated by the rotatable insulator stacks 22-22. Under certain operating conditions the use of only a single movable switch blade 23 may be required together with the associated circuit interrupter 23 as described in US. Gussow et al. Patent No. 3,030,481, issued April 17, 1962. In such case only a single rotatable insulator stack 22 is required together with the over center toggle connection to the crank shaft 40.

What is claimed as new is:

l. A high voltage switch comprising: a pair of insulator stacks rotatably mounted at one end of each stack in parallel spaced relation, a switch blade extending radially from the other end of each insulator stack for movement therewith into or out of contact engagement at their distal ends on conjoint rotation of said insulator stacks in opposite directions to effect said contact engagement or disengagement, an operating arm extending radially from said one end of each insulator stack, a crank shaft rotatable about an axis between said one ends of said insulator stacks, a pair of crank arms one for each insulator stack extending diametrically from and rotatable with said crank shaft, a link interconnecting the distal end of each crank arm with the distal end of the operating arm of the respective insulator stack, stop means cooperating with said crank shaft to limit rotation thereof in either direction after rotation of said crank shaft and therewith said crank arms through at least from one over center toggle locked position to another over center toggle locked position corresponding to rotation of said switch blades into contact engagement in switch closed position and out of contact engagement in switch open position, and means for rotating said crank shaft in one direction or the other from one toggle locked position to the other toggle locked position to swing said switch blades in opposite directions and cause accurate endwise telescoping Contact engagement of said distal ends thereof as said switch blades approach and recede from endwise in line engagement whereby said switch blades are aligned in switch closed position and are movable at high speed between closed and open positions.

2. The invention, as set forth in claim 1, wherein the links are pivotally connected to the operating arms, are pivotally connected to opposite sides of the crank arms, and extend across the axis of rotation of the crank shaft in one over center toggle locked position.

3, The invention, as set forth in claim l, wherein the axis of the crank shaft extends at right angles to the plane of the insulator stacks.

4. The invention, as set forth in claim 3, wherein the crank shaft is offset radially adjacent each crank arm to receive the respective link in the one over center toggle locked position.

5. The invention, as set forth in claim 1, wherein additional stop means individual to each insulator stack limits rotation thereof at the switch closed and switch open positions.

6. The invention, as set forth in claim 1l, wherein: an elongated support carries the insulator stacks and has mounted therein the operating mechanism for rotating said insulator stacks, and shield means on the top sides of said support overlie the moving parts of said operating mechanism to protect the same against icing.

7. The invention, as set forth in claim Il, wherein: an elongated support carries the rotatable insulator stacks, a stationary insulator stack is mounted at one of its ends on said support in parallel outwardly spaced relation adjacent to at least one of said rotatable insulator stacks, a current interrupter is mounted on the other ends of the adjacent rotatable and stationary insulator stacks, and

I means rigidly support the one end of said stationary insulator stack on said support.

8. The invention, as set forth in claim 7, wherein the means rigidly supporting the stationary insulator stack on the elongated support includes: a metallic support extending from said one end of said stationary insulator stack through said elongated support, and means for clamping individually each end of said metallic support to the respective side of said elongated support.

9, In combination: A support structure, an insulator stack carried at one end by said support structure, a metallic support extending from said one end of said insulator stack through said support structure7 said metallic support having one end adjacent said insulator stack .and another end remote therefrom, and means for clamping individually each end of said metallic support to the respective side of said support structure.

10. The invention, as set forth in claim 9, wherein the means for clamping the end of the metallic support adjacent the one end of the insulator stack to the adjacent side of the support structure includes: a rectangular metallic plate through which said metallic support extends and to which it is rigidly secured, and adjusting member at each corner of said metallic plate for adjusting the spacing between it and the juxtaposed surface of said support structure, and retaining means for holding each said corner in adjusted position to said support structure.

11. The invention, as set forth in claim 9, wherein the means for clamping the end of the metallic support remote from the one end of the insulator stack to the adjacent side of the support structure includes: a rectangular metallic plate secured to said support structure and having said remote end of said metallic support extending loosely therethrough, and adjustable clamp means on said metallic plate in angular spaced relation around said remote end of said metallic support for rigidly clamping the same.

References Cited by the Examiner UNITED STATES PATENTS Re. 23,915 12/1954 Gilliland et al. 200-48 1,723,837 8/ 1929 Austin 200-4-8 2,048,106 7/1936 Coil 74--17.5 2,094,087 9/ 1937 Wilkins 200-48 2,095,796 10/1937 Crabbs 200-48 2,539,906 1/1951 Higgins 74-l7.5 2,685,004 7/1954 Lindell 200-48 2,878,331 3/1959 Tjellstedt 200-48 2,978,558 4/1961 Barta 200-48 X 3,192,332 6/1965 Bernatt et al 200-48 3,194,928 7/1965 Mikos 200-48 X 3,196,226 7/1965 Bertling 20G-*48 FOREIGN PATENTS 843,009 3/ 1939 France.

ROBERT K. SCHAEFER, Primary Examiner.

BERNARD A. GILHEANY, KATHLEEN H. CLAFFY,

' Examiners. W. C. GARVERT, Assistant Examiner.

Claims (1)

1. A HIGH VOLTAGE SWITCH COMPRISING: A PAIR OF INSULATOR STACKS ROTATABLY MOUNTED AT ONE END OF EACH STACK IN PARALLEL SPACED RELATION, A SWITCH BLADE EXTENDING RADIALLY FROM THE OTHER END OF EACH INSULATOR STACK FOR MOVEMENT THEREWITH INTO OR OUT OF CONTACT ENGAGEMENT AT THEIR DISTAL ENDS ON CONJOINT ROTATION OF SAID INSULATOR STACKS IN OPPOSITE DIRECTIONS TO EFFECT SAID CONTACT ENGAGEMENT OR DISENGAGEMENT, AN OPERATING ARM EXTENDING RADIALLY FROM SAID ONE END OF EACH INSULATOR STACK, A CRANK SHIFT ROTATABLE ABOUT AN AXIS BETWEEN SAID ONE ENDS OF SAID INSULATOR STACKS, A PAIR OF CRANK ARMS ONE FOR EACH INSULATOR STACK EXTENDING DIAMETRICALLY FROM AND ROTATABLE WITH SAID CRANK SHAFT, A LINE INTERCONNECTING THE DISTAL END OF EACH CRANK ARM WITH THE DISTAL END OF THE OPERATING ARM OF THE RESPECTIVE INSULATOR STACK, STOP MEANS COOPERATING WITH SAID CRANK SHAFT TO LIMIT ROTATION THEREOF IN EITHER DIRECTION AFTER ROTATION OF SAID CRANK SHAFT AND THEREWITH SAID CRANK ARMS THROUGH AT LEAST 180* FROM ONE OVER CENTER TOGGLE LOCKED POSITION TO ANOTHER OVER CENTER TOGGLE LOCKED POSITION CORRESPONDING TO ROTATION OF SAID SWITCH BLADES INTO CONTACT ENGAGEMENT IN SWITCH CLOSED POSITION AND OUT OF CONTACT ENGAGEMENT IN SWITCH OPEN POSITION, AND MEANS FOR ROTATING SAID CRANK SHAFT IN ONE DIRECTION OR THE OTHER FROM ONE TOGGLE LOCKED POSITION TO THE OTHER TOGGLE LOCKED POSITION TO SWING SAID SWITCH BLADES IN OPPOSITE DIRECTIONS AND CAUSE ACCURATE ENDWISE TELESCOPING CONTACT ENGAGEMENT OF SAID DISTAL ENDS THEREOF AS SAID SWITCH BLADES APPROACH AND RECEDE FROM ENDWISE IN LINE ENGAGEMENT WHEREBY SAID SWITCH BLADES ARE ALIGNED IN SWITCH CLOSED POSITION AND ARE MOVABLE AT HIGH SPEED BETWEEN CLOSED AND OPEN POSITIONS.

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