US3070674A

US3070674A - Switch construction

Info

Publication number: US3070674A
Application number: US12529A
Authority: US
Inventors: William A Gussow
Original assignee: S&C Electric Co
Current assignee: S&C Electric Co
Priority date: 1960-03-03
Filing date: 1960-03-03
Publication date: 1962-12-25
Anticipated expiration: 1979-12-25

Description

Dec. 25, 1962 w. A. sussow swmm CONSTRUCTION 13 Sheets-Sheet 1 Filed March 3. 1960 w m G a Dec. 25, 1962 w. A. eussow swncu CONSTRUCTION l3 Sheets-Sheet 2 Filed March 5, 1960 Dec. 25, 1962 w. A. eussow Q 3,070,674

SWITCH CONSTRUCTION Filed Ma rch 3, 1,9 0 15 Sheets-Sheet s 13 Sheets-Sheet 5 x Q %v\\ m: m Q i Mm x v W. A. GUSSOW SWITCH CONSTRUCTION N \Qmw km x MW a M I 5 Q Dec. 25, 1962 Filed March 3. 1960 Dec. 25, 1962 w. A. caussow 3,070,674

SWITCH CONSTRUCTION Filed March 3. 1960 13 Sheets-Sheet 6 \Rm\ E? Q w by k M ii. a Q I O Dec. 25, 1962 w. A. sussow 3,

SWITCH CONSTRUCTION Filed March 3. 1960 13 Sheets-Sheet 7 Dec. 25, 1962 w. A. GUSSOW swI'rcH consmucnom l5 Sheets-Sheet 8 Filed March 3. 1960 Dec. 25, 1962 w. A. eussow SWITCH CONSTRUCTION 15 Sheets-Sheet 9 Filed March 3, 1960 Dec. 25, 1962 w. A. eussow SWITCH CONSTRUCTION l3 Sheets-Sheet 10 Filed March 3. 1960 W. A. GUSSOW SWITCH CONSTRUCTION Dec. 25, 1962 13 Sheets-Sheet 11 Filed March 3. 1960 W. A. GUSSOW SWITCH CONSTRUCTION Dec. 25, 1962 15 Sheets-Sheet 12 Filed March 3, 1960 HH IHHH IHHHHUHHHII I wlllllll l W. A. GUSSOW SWITCH CONSTRUCTION Dec. 25, 1962 1s Sheets-Sheet 15 Filed March 3, 1960 United States Patent 3,070,674 SWITCH CONSTRUCTION William A. Gussow, St. Petersburg, Fla., assignor to S & C Electric Company, Chicago, Ill., a corporation of Delaware Filed Mar. 3, 1960, Ser. No. 12,529 Claims. (Cl. 20048) This invention relates, generally, to high voltage and high current electric switches for high Voltage electric power transmission lines such as 69 kv. and above, and it has particular relation to such switches provided with means for interrupting load current without external arcing. This invention constitutes an improvement over the invention disclosed in application Serial No. 704,397, filed December 23, 1957, now Patent No. 3,030,481, issued April 17, 1962, and assigned to the assignee of this application.

Among the objects of this invention are: To provide for sequentially opening and closing a pair of series connected disconnecting switch blades and load'interrupter contacts in parallel with one of the switch blades in a new and improved manner; to complete the circuit by closing the switch blade in parallel with the interrupter contacts followed by closure or" the interrupter contacts; to provide for effecting such sequential operation using beaver tail type switch blades with a minimum of moving parts exposed to icing thereby reducing the likelihood of improper functioning under adverse operating conditions; to accomplish the circuit opening operation by rotating in one direction an operator, such as an insulator on which the beaver tail type switch blades and a part of the load current interrupter are mounted, first to rotate one switch blade out of high pressure contact engagement with its line contact member and then to swing it to a position relative thereto where the arc cannot be restruck therebetween, then tripping a spring to operate the contacts of the load interrupter to open the circuit, then rotating the other switch blade out of high pressure contact engagement with its line contact member, then recocking the spring and finally swinging the switch blades to open circuit positions at right angles to their closed circuit positions during the remainder of the rotation of the insulator in the one direction; to accomplish the circuit closing operation by rotating the insulator in the opposite direction and thereby moving the beaver tail type switch blades at different speeds to the end that said other switch blade is moved into high pressure contact engagement with its line contact member followed by swinging of the one switch blade into contact engagement with its line contact member to complete the circuit and, during the remainder of the rotation of the insulator, closing the load interrupter contacts and rotating said one switch blade into high pressure contact engagement with its line contact member; to operate the one switch blade and the contacts of the load current interrupter by direct mechanical drive from the rotatable insulator and to operate the other switch blade through a Geneva gear mechanism; to prevent any rotation of the other switch blade during the initial portion of the rotation of the insulator in the sWitch opening direction; to operate a beaver tail type of switch blade into and out of high pressure contact engagement with a line contact member through the agency of a Geneva gear mechanism; to lock the beaver tail type of switch blade in high pressure contact engagement with a line contact member during an initial part of the rotation of the switch blade operating mechanism; and to movably mount two beaver tail type switch blades on a common support and to move one of them into and out of high pressure contact engagement with its line contact member and through a Geneva gear mechanism move the other switch blade into and out of high pres- 3,070,674 Patented Dec. 25, 1962 sure contact engagement with its line contact member in predetermined timed relation to the rotation of the one switch blade.

Other objects of this invention will, in part, be obvious and in part appear hereinafter.

This invention is disclosed in the embodiment thereof shown in the accompanying drawings and it comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth and the scope of the applica: tion of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of this invention, reference can be had to the following detailed description, taken together with the accompanying drawings, in which:

FIGURE 1 is a view, in side elevation, of one pole of a three pole high voltage load interrupter disconnecting switch mechanism in which the present invention is embodied;

FIGURE 2 is a top plan view of the construction shown in FIGURE 1;

FIGURE 3 is a horizontal sectional view taken generally along the line 33 of FIGURE 1 and showing certain of the details of the switch operating mechanism for rotating the intermediate insulator;

FIGURE 4 is a top plan view, at an enlarged scale, of the mechanism housing and the rotatable mountings thereon for the switch blades;

FIGURES 5A, 5B and 5C taken together and placed in endwise relation in the order named show a vertical longitudinal sectional view through the load interrupter, the contacts being shown in the closed positions;

FIGURE 6 is a vertical sectional view taken generally along the line 66 of FIGURE 4, certain of the parts being shown generally in the positions that they occupy in the switch closed position and other parts being shown' in the plane of the drawing to show the relationship between the parts illustrated;

FIGURE 7 is a top plan view, with certain parts being broken away and others omitted, of the operating mechanism, the parts being shown generally in their relationship for the switch closed position;

FIGURE 8 is a view, similar to FIGURE 7, showing the positions of certain parts of the operating mechanism after rotation of the main shaft through 22 from the position shown in FIGURE 7;

FIGURE 9 is a view, similar to FIGURE 7, showing the positions of certain parts of the operating mechanism after rotation of the main shaft through 58 /2 from the position shown in FIGURE 7, the interrupter contacts being open and the operating springs recocked;

FIGURE 10 is a view, similar to FIGURE 7, showing the positions of certain parts of the operating mechanism after rotation of the main shaft through 113 from the position shown in FIGURE 7;

FIGURE 11 is a vertical elevational view, at an enlarged scale, showing the layout of the cross head which is operated by the switch operating mechanism for opening the contacts of the load current interrupter and for thereafter reclosing them, the closed position of the cross head being shown by full lines and the open position corresponding to the open position of the t contacts of the load interrupter being shown by broken lines;

FIGURE 12 is a vertical sectional view taken generally along the line 1212 of FIGURE 11 and turned through in order to place it on the sheet where it appears;

FIGURE 13 is a partial elevational view at an enlarged scale showing the relationship between the main and auxiliary shafts and the Geneva drive mechanism therebetween;

FIGURE 14 is an enlarged view, partly in side elevation and partly in section, showing the interrupter closing push rod;

FIGURE 15 is a top plan view of the interrupter trip actuator which is keyed to and therefore rotates with the main shaft; and

FIGURE 16 is a view which shows a development of the depending flange forming an integral part of the interrupter trip actuator, shown in FIGURE 15, to show in more detail the relative location of the Operating shoulder on this depending flange.

Referring now particularly to FIGURES 1, 2 and 3 of the drawings, it will be observed that the reference character designates, generally, a switch base. The switch base 10 can be formed of a pair of back-toback rolled steel channel sections 10 interconnected by

transverse plates

11, 12 and 13 on which

support fittings

14, 15 and 16 are mounted. It will be observed that the fitting 15 is rotatably mounted on the transverse plate 12 while the fittings 14 and 16 are stationarily mounted on the transverse plates 11 and 13, respectively. First, intermediate and second insulators 17, 18 and 19 are mounted on the

support fittings

14, 15 and 16, respectively. It will be observed that the intermediate insulator 18 is rotatable about a vertical axis in the switch position shown in the drawings together with the support fitting 15 while the first and second insulators 17 and 19 are stationarily mounted on the support fittings 14 and 16 respectively.

Any suitable means can be provided for rotating the support fitting 15 in order to rotate the intermediate insulator 18 through the necessary extent to effect the operation of the switch for opening and closing the circuit in the manner hereinafter set forth. For illustrative purposes it is pointed out that provision is made for rotating the intermediate insulator 13 through 113 from the switch closed position to the switch open position and vice versa. For rotating the intermediate insulator 18 an arm 20 extends radially from the fitting 15 as shown in FIGURE 3 and it is pivotally connected at 21 to one end of a clevis member 22 which is pivotally connected at the other end at 23 to an arm 24 which extends from and rotates with a shaft 25 that is journaled on a bearing 26 which is carried by the channel sections 10 forming the switch base 10. It will be observed that the bearing 26 is mounted on a transverse plate 27 secured to and extending between the channel sections 10. An arm 28 is secured to and rotates with the shaft 25 and is arranged to be connected at its outer end to an interphase rod (not shown) which serves to effect the simultaneous operation of the other two poles of the switch construction in the manner set forth in the application above referred to. Since the present invention is embodied in the construction of a single pole unit, the multiple pole construction has not been shown herein. It will be understood that the ratchet mechanism disclosed in the application above referred to can be employed in conjunction with the movement of the arm 28 from one position to the other if such operation is desired.

For illustrative purposes the switch base 10 is hown in a horizontal position with the first, intermediate and second insulators 17, 18 and 19 extending upwardly therefrom. It will be understood that the switch base 10 can be located in a vertical position where the insulators 17, 18 and 19 would extend horizontally one above the other. Also the insulators 17, 18 and 19 can depend from the switch base 10 where an underhung construction is desired. Thus, where there is a reference herein to upper and lower locations it will be understood that they are with reference to the particular arrangement shown, it being understood that other locations can be employed, as described.

Mounted at the upper end of the first insulator 17, as shown in FIGURES 1 and 2 of the drawings, there is a first line contact member 29 which includes a pair of inverted U-shaped contact members 30. In like manner a second line contact member 31 is mounted at the upper end of the second insulator 19 and it is provided with inverted U-shaped contact members 32. Arcing horns 33 and 34 are provided on the first and second

line contact members

29 and 31 for the usual purposes. Cooperating with the first and second line contact members are a first switch blade 35 of beaver tail type having a beaver tail contact 36 for engagement with the inner flexible arms of the contact members 30 and a second switch blade 37, also of beaver tail type, having a beaver tail contact 38 for likewise engaging the inner flexible arms of the inverted U-shaped contact members 32. Arcing tips 39 and 40 extend endwise from the first and

second switch blades

35 and 37 for engaging the arcing horns 33 and 34, respectively, to provide the final break and the initial make as the respective switch blades "35 and 37 are moved out of and into switch closed positions.

Provision is made, as disclosed in more detail in US. Patent 2,818,474, issued December 31, 1957, for rotating the first and

second switch blades

35 and 37 about their longitudinal and transverse axes into and out of high pressure contact engagement with the first and second

line contact members

29 and 31. The

switch blades

35 and 37 are mounted in this manner on a mechanism housing 43 of conducting material, such as aluminum, which is supported on the intermediate insulator 18 at its upper end. As will appear hereinafter, provision is made for holding the mechanism housing 43 stationary with respect to the intermediate insulator 18. On opposite sides of the mechanism housing 43 are brackets 44- and 45 which extend upwardly for receiving

blade carriers

46 and 47 that are pivoted about

horizontal axes

48 and 49 extending through the

brackets

44 and 45. Bearings 50 and 51 are carried by the

blade carriers

46 and 47 for rotatably mounting the adjacent ends of the first and

second switch blades

35 and 37. With a view to rotating the

switch blades

35 and 37 about their longitudinal axes in the bearings 50 and 51, clamp portions 52 and 53 are secured to them adjacent these bearings having arms 54 and 55 extending therefrom. The arms 54 and 55 are pivoted at 56 and 57 to clevises 58 and 59 from which links 60 and 61 extend for connecting them to

sockets

62 and 63 with which

upstanding pins

64 and 65 interfit. The

pins

64 and 65 are carried by first and second switch cranks 66 and 67 that are arranged to rotate in horizontal planes. The first switch crank 66 is associated with the first switch blade 35 and is operable to effect its rotation about its longitudinal axis and also about a transverse axis into and out of high pressure contact engagement with the first line contact member 29. The first switch crank 66 is keyed to and rotates with a main shaft 68 that is journaled in the mechanism housing 43. The second switch crank 67 is keyed to and rotates with an auxiliary shaft 69, parallel to the main shaft 68 and journaled in the mechanism housing 43. As will appear hereinafter when the auxiliary shaft 69 and therewith the second switch crank 67 rotates through from the switch closed position shown in FIGURE 2, the second switch blade 37 is rotated out of high pressure contact engagement with the second line contact member 31 and into a position at right angles to the horizontal switch closed position. As will be pointed out hereinafter, the driving connection between the main shaft 68 and the auxiliary shaft 69 is such that, during the first 40 of rotation of the former in a counterclockwise direction from the switch closed position together with the first switch crank 66, no rotation of the auxiliary shaft 69 or second switch crank 67 occurs. During this 40 rotation of the main shaft 68 and the first switch crank 66, the first switch blade 35 is rotated out of high pressure contact engagement with the first line contact member 29 and is swung away therefrom. During the remaining 73 of counterclockwise rotation of the main shaft 68 and the first switch crank 66 the opening movement of the first switch blade 35 is completed and the auxiliary shaft 69 and the second switch crank 67 are rotated in a clockwise direction through 85 to rotate the second switch blade 37 out of high pressure contact engagement with the second line contact member 31 and to swing it away therefrom. At the termination of these switch opening movements the first and

second switch blades

35 and 37 extend upwardly in parallel relation.

If desired, counterbalancing springs can be provided, as described in the application above referred to, for the first and

second switch blades

35 and 37. Covers 70 and 71 overlie these counterbalancing springs when they are used.

As shown more clearly in FIGURES 1 and 6 of the drawings the main shaft 68 is journaled in the mechanism housing 43 and projects from the under side thereof into an operator 72 in the form of a fitting that is bolted to the upper end of the intermediate insulator 18. Set screws 73 extending radially through an upstanding flange of the operator '72 into the lower end of the main shaft 68 and a key 72 serve to interconnect these parts.

It is desirable to limit the extent of movement of the switch cranks 66 and 67 for the switch closed and open positions. As shown in FIGURE 4 of the drawings, stops 74 and 75 project upwardly from the top of the mechanism housing 43 for determining the positions of the first and second switch cranks 66 and 67, respectively, in the switch closed positions where the first and

second switch blades

35 and 37 are in the high pressure contact engaging positions with the respective first and second

line contact members

29 and 31. The positions of the first and second switch cranks 66 and 67 here are shown by full lines. The positions of the first and second switch cranks 66 and 67, corresponding to the open positions of the first and

second switch blades

35 and 37, are shown by dot and dash lines. Stops 76 and 77 are provided for limiting the movement of the first and second switch cranks 66 and 67 to these positions. In the open positions of the first and

second switch blades

35 and 37, they extend parallel to each other and at right angles to the switch closed positions shown in FIGURE 1 of the drawmgs.

The first switch blade 35 is positioned mechanically and electrically in parallel circuit relation with a load current interrupter that is indicated, generally, at 80. The load current interrupter 80 is interposed between the first line contact member 29 and the mechanism housing 43 on which the first and

second switch blades

35 and 37 are rotatably mounted. The load current interrupter 80 is formed of a number of interrupter units 81. For illustrative purposes four interrupter units 81 have been shown. They correspond generally in construction and operation to the auxiliary contact constructions described in the application above referred to. Generally the interrupter units 81 are of identical construction, the number used depending upon the voltage of the circuit to which the switch construction is applied. The interrupter units 81 are of the type in which the arc drawn therein is extinguished in air. Other types, such as vacuum or gas filled interrupter units, can be used instead of the particular one disclosed herein.

FIGURES 5A-5B5C, placed end to end from left to right, show the details of construction of the load current interrupter 80. At the left end there is a terminal plate 82 which is secured by bolts 82 to the first line contact member 29. At the right end there is a metallic adapter 83 which is secured by bolts 83' to the mechanism housing 43. A conducting gasket is interposed therebetween to provide a good conducting path therebetween.

Each of the interrupter units 81 includes an insulator bushing or housing 84 having at its left end a female metallic bushing flange 85 and at its right end a male metallic bushing flange 86. As shown, studs 86" with suitable nuts and lock washers serve to interconnect the juxtaposed bushing flanges and 86. At the left end of the load current interrupter 80, the studs 86 serve to interconnect the bushing flange 85' to the terminal plate 82 while at the right end the studs 36' serve to interconnect the bushing flange 86 to the adapter 83. Passageways 87 are provided between the

bushing flanges

85 and 86 for the escape of the are products on operation of the load current interrupter 80 and discharge thereof to the atmosphere.

Within the central portion of the terminal plate 82 and within each of the central portions of the bushing flanges 86 there is provided a stationary interrupter contact sleeve 88 which is held in place and against rotation in each case by set screws 89. Formed integrally with and extending to the right of each interrupter contact sleeve 88 are contact fingers 90. The contact fingers 90 extend into a metallic Vent chute 91 which is held in place on the respective bushing flange 85 by bolts 92. Extending from the metallic vent chute 91 is a removable cartridge, shown generally at 93, which is surrounded by a cylindrical insulating housing 94 that may be formed of a phenolic condensation product and secured by radially extending screws 95 to the metallic vent chute 91. The replaceable cartridge 93 includes an insulating retaining ring 96. In order to provide a gas tight relationship an 0 ring 97 is interposed between the outer end of each metallic vent chute 91 and the associated surface of the respective bushing flange 85. For the same purpose another 0 ring 97 is interposed between the juxtaposed portions of the cylindrical housing 94 and the insulating retaining ring 96 which forms a part of the replaceable cartridge 93. Secured to and extending from the insulating ring 96 is an insulating sleeve 98, preferably formed of fiber, within which there is provided a stack 99 of fiber washers. The stack 99 of fiber washers is cemented in place within the insulating sleeve 98 audit provides a longitudinally extending bore 100 in which the arc is drawn and extinguished.

The are is drawn in each bore 100 from the associated contact fingers 90 by a contact tip 101 that is movable through the bore 100. The contact tips 101 are mechani cally interconnected so that they move simultaneously through the respective bores 100 and, when four interrupter units 81 are provide, four arcs are drawn and four gaps are provided in the load current interrupter 80 when these arcs are extinguished. Extending from each of three of the contact tips 101 is a tubular moving contact extension 102 that is slotted lengthwise and is provided with openings 103 to permit the flow of the are products from the interior of each extension 102 into the bore 100 and thence through recesses 104, aligned with the contact fingers 90 outwardly through the metallic arcing chute 91 and thence to the atmosphere through the passageways 87.

It will be observed that the contact tips 101 are tubular in construction. Telescoped within each contact tip 101 is a metallic sleeve 107 that is suitably secured thereto. Telescoped Within the metallic sleeve 107 is one end of a trailer rod 108 of insulating material. The metallic sleeve 107 is preferably secured by cement to the trailer rod 108. In order to protect the trailer rod 108 from the arc that is drawn between the contact fingers 90 and the contact tip 101, an insulating sleeve 109 surrounds the end of the metallic sleeve 107 nearer to the vicinity where the arc is drawn. The trailer rod 108 extends through a tubular trailer 110 that is formed of a material, such as methyl methacrylate resin, from which a suitable arc extinguishing medium can he evolved when the arc is drawn for assisting in extinguishing it. At the outer end of each trailer rod 108 there is provided a longitudinally split trailer stop sleeve 111 that serves to hold the tubular trailer 110 in position and causes it to move conjointly with the trailer rod 108. The trailer stop sleeve 111 is formed of insulation and is secured to the trailer rod 188. To the left of each of the trailer stop sleeves 111 there is a metallic trailer hitch socket 112 for the purpose of facilitating mechanical interconnection to the adjacent contact tip 1'81 by telescopic engagement with the adjacent end of the tubular moving contact extension 102 of the next unit. The exposed trailer hitch socket 112 at the left end, as shown in FIGURE A, is provided with a cover sleeve 112. In order to interconnect each tubular moving contact extension 182 to the adjacent stationary interrupter contact sleeve 88 contact followers 113 are provided having contact fingers 114 which bear against the inner surface of the next contact sleeve 88.

When the contact tips 101 of the interrupter units 81 are separated from their cooperating contact fingers 91), it is desirable that the voltage there-between be distributed uniformly across the several interrupter units 81. For this purpose a voltage distributing resistor 117 is provided within each insulator bushing or housing 84. The voltage distributing resistors 117 are of conventional construction and are formed by applying a high resistance film on the outer surface of a cylindrical insulator and then silver coating the inner surfaces at the ends and connecting the silver coating to the resistance coating on the exterior for contact engagement by contact fingers 118 and 119 which are connected respectively to the ends of each of the interrupter units 81. As shown, the contact fingers 118 are connected to the respective metallic vent chutes 91 at the left end and the contact fingers 119 are connected to the respective bushing flanges 86 at the right end.

Since the interrupter unit 81 at the right end of the load current interrupter 80, as shown in FIGURE 5C, is adjacent the mechanism housing 43, a slightly different construction is provided for connection to the contact tip 101 in order to interconnect it with the operating mechanism within the mechanism housing 43. It will be observed that a tubular moving contact extension 120 is provided in the form of an unperforated tube and is suitably mechanically connected to the contact tip 101. At the right end of the contact extension 120 there is telescoped one end of a plug 121 which is secured in position by pins 122 extending at right angles to each other. Threaded on the plug 121 is a coupling sleeve 123 and it is surrounded by an insulating band 124 to prevent electrical contact between the coupling sleeve 123 and a metallic sleeve 125 that extends through the bushing flange 86 and corresponds to the contact sleeves 88 previously referred to. The coupling sleeve 123 forms a part of a quick detachable coupling 126 between the contact extension 120 and an interrupter contact operating tube 127 which extends through the adapter 83 and a side wall of the mechanism housing 43 for connection to the operating mechanism therein in a manner to be described hereinafter. At its right end the interrupter contact operating tube 127 is provided with a cross head 128 for operation by the mechanism in the mechanism housing 43.

In order to provide access to the quick detachable coupling 126 when the interrupter contact operating tube 127 is moved to the open circuit position where the quick detachable coupling 126 is shown by broken lines, removable cover plates 129 are provided on the adapter 83. The cover plates 129 are held in position by screws 130. As shown in FIGURE 5A a cover plate 131 is provided on the terminal plate 82 and is held in place by bolts 132. When the interrupter contact operating tube 127 is moved to the open circuit position with the quick detachable coupling 126 located within the adapter 83, as shown by broken lines, on removal of the cover plates 129, the coupling 126 can be detached from the tubular moving contact extension 126. Then, on removal of the cover plate 131 mounted on the terminal plate 82, the contact tips 101 and associated parts including the tubular trailers 110 can be removed as a unit for repair, replacement or merely inspection as may be desired.

Referring now particularly to FIGURES 11 and 12 of the drawings the manner in which the cross head 128 is mounted is shown more clearly. It will be observed that the left side of the cross head 128 is provided with a convex curved surface 137 that is arranged to be engaged by fork extensions 138 of an operating spring arm 139, FIGURE 6, which extends radially from an operating spring socket 140' that is freely rotatably mounted on the main shaft 68. As will appear hereinafter provision is made for biasing the operating spring arm 139 to open the contacts of the load current interrupter 80 at high speed.

Referring again to FIGURES 11 and 12 of the drawings it will be observed that the upper fork extension 138 is beveled at 141 for engaging a beveled latch release surface 142 of a latch 143 which is pivoted at 144 on a latch support 145. The latch 143 has a latch surface 146 that is arranged, as shown by full lines, to be placed to the right of the cross head 128 for the purpose of holding it in the position corresponding to the closed position of the load current interrupter 80. A coil spring 147 serves to bias the latch 143 to the latched position. As the fork extensions 138 move to the right, as described hereinafter, the beveled surface 141 engages the beveled latch release surface 142 and lifts the latch 143 to move the latch surface 146 out of the path of the cross head 128 followed by engagement of the right sides of the fork extensions 138 with the convex curved surface 137 to initiate and complete the opening movement of the cross head 128 and interrupter contact operating tube 127. The right end or nose portion 148 of the latch 143 is provided with an inclined approach surface 148' for engaging the left side of the upper fork extension 138 when it is moved to the left for lifting the latch 143 upwardly sufficiently far to clear the upper end of the cross head 128.

At the right end of FIGURE 11 the position of the cross head 128 in the open position is shown by broken lines. In order to move the cross head 128 from the open position to the closed position as shown at the left of FIGURE ll by full lines, a roller 149 is mounted on a pin 150 which is carried by fork extension 151 of an interrupter closing lever 152 the details of construction of which are shown more clearly in FIGURE 14 of the drawmgs.

The movement of the cross head 128 and of the interrupter contact operating tube 127 is guided by guide rods 153 which extend transversely of the mechanism housing 43 and in which they float at the ends in drilled holes in the walls thereof. As shown in FIGURE l 1, bolts 154 and suitable lock nuts hold the guide rods 153 endwise in place. It will be understood that the cross head 128 is apertured to receive the guide rods 153 and that it is slidably mounted thereon. Set screws 155, FIGURE 12, extending into the guide rods 153 from the latch support 145 serve to prevent them from rotating about their longitudinal axes. In order to absorb the shock incident to the stopping of the cross head 128 in the open position as shown by the broken lines at the right of FIGURE 11, Washers of shock absorbing material 156 are mounted on the right ends of the guide rods 153 for engagement by the right side of the cross head 128. Stop pins 157, extending into the guide rods 153, are arranged to be engaged by the curved surface 137 of the cross head 128 for limiting its movement and thereby of the interrupter contact operating tube 127 in the closed direction. It is desirable that there be a low conductivity path between the cross head 128 and the mechanism housing 43. For this purpose a shunt 158 is secured by screws 159 to the lower end of the cross head 128 and, as shown in FIG- URE 6, is secured by screws 160 at the other end to the mechanism housing 43.

It has been pointed out hereinbefore that the main shaft 68 is rotated by the intermediate insulator 18 for effecting a corresponding rotation of the first switch crank 66 and thereby operation of the first switch blade 35. Also it has been pointed out that the auxiliary shaft 69, mounted in parallel relation on the mechanism housing 43, is arranged to rotate the second switch crank '67 for thereby rotating the second switch blade 37. The arrangement is such that the first switch blade 35 is rotated out of high pressure contact engagement with the first line contact member 29 in order to place the load current interrupter 80 in series with the circuit so that, on further rotation of the main shaft 68, the contacts of the load current interrupter 80 are opened to interrupt the flow of current in the circuit while the second switch blade 37 still remains in high pressure contact engagement with the second line contact member 31. Thereafter, the auxiliary shaft 69 is rotated in order to rotate the second switch blade 37 out of high pressure contact engagement with the second line contact member 31 so that, in addition to the air gaps provided in the circuit by the separation of the contacts of the load current interrupter 80, a large air gap is provided on movement of the second switch blade 37 to the open positionat right angles to its normally closed position. It remalns to point out the apparatus for performing these operations and how the auxiliary shaft 69 is driven in timed relation from the main shaft 68.

Referring particularly to FIGURE 6 of the drawings it will be observed that a spring base 164 is rotatable on the main shaft 68. The spring base 164 is arranged to be held stationary with respect to the mechanism housing 43 in any one of several difierent angular positions by a locking bolt 166'. The reason for adjustably mounting the spring base 164 is to vary the operating tensions of inner and

outer coil springs

167 and 168 which are connected at one end to the spring base 164 and at the other end to the operating spring socket 140 from which the operating spring arm 139 extends radially and carries at its outer end the fork extensions 138 which are arranged to engage the cross head 128, FIGURE 11, for moving the interrupter contact operating tube 127 to the open position and opening the contacts of the interrupter units 81 of the load current interrupter 80.

As shown more clearly in FIGURE 7 of the drawings the operating spring socket 140 together with the operating spring arm 139 formed integrally therewith is shown in the cocked position with the

springs

167 and 168 fully stressed. Extending radially from the operating spring socket 140 opposite the operating spring arm 139 is an arcuate trip cam 169 which has a shoulder 170 that is engaged by a shoulder 171 of a trip latch 172 which is pivoted on a stub shaft 173 that is carried by the mechanism housing 43. A spring 17 4 urges the trip latch 172 in a counterclockwise direction, as viewed in FIGURE 7, to permit the shoulder 171 thereon to move into latching engagement with the shoulder 170 when the operating spring socket 140 is restored to the cocked position shown in FIGURE 7. The trip latch 172 is operated by a trip finger 175 which also is pivotally mounted on the stub shaft 173. As shown in FIGURE 6, the trip finger 175 is journaled on an upstanding sleeve portion of the trip latch 172. The trip finger 175 has a shoulder 176 that is arranged to engage a shoulder 177 on the trip latch 172. Thus, when the trip finger 175 is rotated in a clockwise direction, its shoulder 176 engaging the shoulder 177 on the trip latch 172, causes rotation of the latter and moves the shoulder 171 out of the path of the shoulder 170 on the arcuate trip cam 169 and permits the operating spring socket 140 to be rotated in a clockwise direction under the influence of the coil springs 167 and 168. The trip latch 172 is held in the unlatched position by engagement with the outer periphery of the arcuate trip cam 169. A coil tension spring 178 interconnects the trip latch 172 and the trip finger 175 and serves to hold the shoulder 176 of the latter in engagement with the shoulder 177 of the trip latch 172.

The trip finger 175 has a shoulder 179 that extends radially thereof into the path of a trip edge 180 on a depending flange portion or trip segment 181, FIGURES 15 and 16, of an interrupter trip actuator 182 that is secured by a key 183, FIGURE 6, to the main shaft 68 and thus rotates therewith. Referring again to FIGURES l5 and 16, it will be observed that the trip edge 18 located at one end of the depending flange portion or trlp segment 181 that is formed integrally with the interrupter trip actuator 182. The arcuate length of the trip segment 181 is about 43 and it serves to hold the trip finger 175 and thereby the trip latch 172 in the unla-tched position as long as the outer end of the trp finger 175 engages the outer surface of the trip segment 181.

Also forming an integral part of the interrupter trip actuator 182 and therefore movable therewith is a radially extending arm 187 which is provided with a push bolt 188 that is arranged, as shown in FIGURE 7 of the drawings, to engage a shoulder 189 on the operating spring arm 139. The purpose of this construction is to return the operating spring socket 140 and parts associated therewith to the initial position and to recock the

springs

167 and 168. The interrupter trip actuator 182 also is provided with a pair of radially extending arms 190 between which there extends a pin 191 on which a roller 192 is mounted.

As shown in FIGURE 7, the roller 192, which is movable with the interrupter trip actuator 182, is arranged to engage an arm 196 which is freely rotatably mounted on a shaft 197, FIGURE 14, which is mounted in the mechanism housing 43. Also mounted on the shaft 197 is a sleeve 198 which is an integral part of the interrupter closing lever 152 which carries the roller 149 between the fork extensions 1'51 at its outer end for engaging the right side of the cross head 128, FIGURE 11, to move it to the closed position corresponding to the closed position of the load current interrupter 80. Also integral with the interrupter closing lever 152 is an arm 199, FIGURE 7, through which an adjusting bolt 200 extends. By adjusting the bolt 200 the spacing between the arm 196 and the arm 199 can be varied in turn to vary the relationship between the positions of the roller 192 movable with the interrupting trip actuator 182 and the interrupter closing lever 152. A leaf spring 201 serves to bias the arm 196 into engagement with the adjusting bolt 200. A coil spring 202, surrounding the lower portion of the sleeve 198, FIGURE 14, serves to bias the interrupter closing lever 1-52 in a clockwise direction as viewed in FIGURE 7. An adjusting bolt 203 intermediate the ends of the interrupter closing lever 152 determines the extent to which it can swing in a counterclockwise direction.

'The driving connection between the main shaft 68 and the auxiliary shaft 69 is through the agency of a Geneva gear drive that is shown generally at 206 in FIGURE 7. The Geneva gear drive 206 includes a pair of Geneva driver arms 207 that are secured by a key 208, FIGURE 6, to the main shaft 68 and therefore rotate therewith. A pin 209 extends through the outer ends of the driver arms 207 and a main Geneva roller 210 is mounted thereon. Upstanding from the upper driver arm 207 is a pin 211 on which an auxiliary Geneva roller 212 is mounted. The auxiliary Geneva roller 212 is arranged, as shown in FIGURE 7, when the first and second switch cranks 66 and 67 are in the positions corresponding to the closed and locked positions of the first and

second switch blades

35 and 37 to engage a depending shoulder 213 of an auxiliary Geneva cam arm 214 which, as shown, in FIG- URE 6, is secured by a key 215 to a sleeve 216 that is secured by a key 217 to the auxiliary shaft 69. Thus the auxiliary Geneva cam arm 214 and the sleeve 216 rotate conjointly with the auxiliary shaft 69. Since the roller 212 is in the path of the depending shoulder 213, as the main shaft 68 rotates and carries with it the pair of Geneva arms 207 and the auxiliary Geneva roller 212, the auxiliary Geneva cam arm 214 is held stationary by the interaction between the roller 212 and the depending shoulder 213. It will be noted that the depending shoulder 213 forms one side of a slot 218 that opens down 11 wardly below the auxiliary Geneva cam arm 214. The other side of the slot 218 is formed by a shoulder 219.

The continued rotation of the pair of Geneva driver arms 207 with the main shaft 68 causes the auxiliary Geneva roller 212 to move beyond the shoulder 213 and out of the slot 218. When this takes place, the main Geneva roller 210 moves into an arcuate slot portion 222 that is located between

arms

223 and 224 of a main Geneva cam 225 which is integral with the sleeve 216. Thus the main Geneva cam 225 rotates conjointly with the auxiliary Geneva cam arm 214. While the main Geneva roller 210 is moving through the arcuate slot portion 222 in the main Geneva cam 225, since the center of this arcuate slot portion 222 is the axis of rotation of the main shaft 68, no rotary movement of the main Geneva cam 225 or rotation of the auxiliary shaft 69 can take place. While the main Geneva roller 210 is moving through the arcuate slot portion 222, the second switch crank 67 is held stationary and likewise no movement of the second switch blade 37 takes place. On continued rotation of the pair of Geneva driver arms 207 with the main shaft 68, the main Geneva roller 210 engages the outer end of a radial slot portion 226 between the

arms

223 and 224. Further rotation of the main shaft 68 directly elfects rotation of the main Geneva cam 225 and thereby rotation of the auxiliary shaft 69 to rotate the second switch crank 67. This action rotates the second switch blade 37 to unlocked position and then out of high pressure contact engagement with the second line contact member 31 followed by rotation of the second switch blade 37 to the fully open position.

It will be seen that the auxiliary Geneva roller 212 is used to hold the second switch blade 37 locked in closed position while the main shaft 68 keeps on rotating through the first 40 from the closed position of the first switch crank 66 and of the first switch blade 35. The same holding operation can be effected by extending the arcuate slot portion 222 to receive the main Geneva roller 210 in the position that it occupies in FIGURE 7 and omitting the auxiliary Geneva roller 212 and associated parts. However, this would require a substantial increase in the distance between the main shaft 68 and the auxiliary shaft 69 together with an increase in the size of the oper ating mechanism and of the mechanism housing 43.

The operation of the switch construction disclosed herein will be readily understood from a consideration of the positions of the various parts when the switch is in the fully closed position and followed by a description of what takes place when the intermediate insulator 18 is rotated to open the circuit. Then giving consideration to the positions of the various parts of the mechanism when the switch blades 35 and 3'7 are in the open position and the load current interrupter 80 likewise is in the open position, outlining the sequence of operations for closing the circuit and restoring the switch to the switch closed position.

As shown in FIGURES 1 and 2. of the drawings, the first and

second switch blades

35 and 37 are in high pressure contact engagement with the first and second

line contact members

29 and 31, respectively. As shown in FIGURE 4 by full lines, the first and second switch cranks 66 and 67 occupy positions 9 past the respective lines through the longitudinal axes of the first and

second switch blades

35 and 37 and the axes of rotation of the main shaft 68 and the auxiliary shaft 69. For illustrative purposes in FIGURE 4 the first and

second switch blades

35 and 37 are shown by full lines in the unlocked positions to which they are rotated after a rotation of the respective switch cranks 66 and 67 through 9 to the aligned positions just described. As shown in FIGURES ABC the contact tips 101 of the interrupter units 81 engage the respective contact fingers 90. Thus both

switch blades

35 and 37 are closed and the load current interrupter 80 is closed in parallel with the first switch blade 35. The inner and

outer coil springs

167 and 168 are stressed or fully cocked. As shown in FIGURE 7, the auxiliary Geneva roller 212 engages the shoulder 213 on the auxiliary Geneva cam arm 214 and thus holds the second switch crank 67 and thereby the second switch blade 37 in locked high pressure contact engagement with the second line contact member 31. The parts within the mechanism housing 43 generally are as illustrated in FIGURE 7 with the trip latch 172 engaging the shoulder of the trip cam 169 to hold the interrupter trip actuator 182 against rotation under the biasing action of the coil springs 167 and 168.

In opening the switch, the arm 28, FIGURE 3, is to tated in a clockwise direction from the over center toggle locked position to rotate the arm 20 and thereby the intermediate insulator 18 in a counterclockwise direction. This rotates the main shaft 68, FIGURE 2, in the same direction. After the main shaft 68 has rotated through 9 and therefore the first switch crank 66 has rotated a similar extent to the position shown by the broken lines in FIGURE 4, the first switch blade 35 is rotated about its longitudinal axis to the center position here shown. Thus the first switch blade 35 has been moved from the locked position to the center position and still is in high pressure contact engagement with the first line contact 29. Meanwhile the auxiliary shaft 69 remains motionless and the second switch blade 37 remains in the closed and locked position.

The operator continues to rotate the operating mechanism attached to the arm 28 and thus continues the rotation of the main shaft 68 in a counterclockwise direction an additional 13 of through a total of 22 from the initial position. At this point the first switch blade 35 starts to swing about the horizontal pivot 48 since it has completed its rotation about its longitudinal axis out of high pressure contact engagement with the first line contact member 29. Now the first switch blade 35 starts to swing away from the first line contact member 29 toward the open position.

Meanwhile the auxiliary Geneva roller 212, FIGURE 7, is moving through the slot 218 on the underside of the auxiliary Geneva cam arm 214 and, by engaging the shoulder 213, acts to hold the auxiliary shaft 69 and parts connected thereto against any rotation. The second switch blade 37 is held in locked high pressure contact engagement with the second line contact member 31. As the auxiliary Geneva roller 212 moves through the slot 218, the main Geneva roller 210 enters the arcuate slot portion 222 of the main Geneva cam 225. Since this portion of the slot 222 is concentric with the axis of rotation of the main shaft 68, the main Geneva cam 225 remains stationary While the main Geneva roller 210 moves through the arcuate slot portion 222 and the second switch blade 37 remains in the locked high pressure contact engagement position with the second line contact member 31.

Meanwhile the trip latch 172 engages the arcuate trip cam 169 on the operating spring socket 140 and it is held thereby against movement under the influence of the

springs

167 and 168. The interrupter trip actuator 182 rotates conjointly with the main shaft 68 and the roller 192 carried by the arms 190 thereof moves away from the arm 196 thereby permitting the spring 202 to rotate the interrupter closing lever 152 in a clockwise direction away from the cross head 128 to the position shown in FIGURE 8 of the drawings.

Referring to FIGURE 8 with continued rotation of the main shaft 68 through an additional 18, the first switch blade 35 swings the arcing tip 39 thereon away from the arcing tips 33 which form a part of the first line contact member 29. The entire flow of current then is transfer-red to the load current interrupter in series with the closed second switch blade 37. The auxiliary Geneva roller 212 moves out of the slot 218 on the underside of the auxiliary Geneva cam arm 214 and the 13 main Geneva roller 210 enters the arcuate slot 222 as previously described.

The rotation of the main shaft 68 is continued through an additional l8 /z or a total of 58% from the initial position. Here the first switch blade 35 and its arcing tip 39 have been moved to a position away from the first line contact member 29 and the arcing horns 33 far enough to prevent any flashover therebetween should the load current interrupter 80 be operated to the open circuit position. As shown in FIGURE 9, the interrupter trip actuator 182 is rotated likewise and the trip edge 180 of the depending flange portion 181 engages the shoulder 179 on the trip finger 175 and causes it to rotate in a clockwise direction, carrying with it the trip latch 172. This disengages the shoulder 171 on the trip latch 172 from the shoulder 170 on the arcuate trip cam 169 of the operating spring socket 140. On release of the arcuate trip cam 169 the interrupter trip actuator 182 is released and it swings in a clockwise direction under the biasing action of the

springs

167 and 168 to the position shown by full lines.

As illustrated in FIGURE 9 of the drawings the operating spring arm 139 moves through an arc of 10 before the fork extensions 1 38 engage the cross head 128. During this movement the beveled surface 141, FIGURE 11, engages the beveled latch release surface 142 of the latch 143 and lifts it out of the path of the cross head 128. Under the influence of the

springs

167 and 168 the operating spring arm 139 swings to the position shown by the broken lines in FIGURE 9 carrying with it the cross head 128 and interrupter contact operating tube 127 until the cross head 128 engages the washers 156 of shock absorbing material. The movement of the interrupter contact operating tube 127 is accompanied by separation of the contact tips 101 from the contact fingers 90 in each of the interrupter units 81 with the result that the circuit is interrupted simultaneously at four places and four arcs are drawn and extinguished. This leaves the voltage distributing resistors 117 in series between the first line contact member 29 and the mechanism housing 43 and in series with the second switch blade 37 which still is in the closed circuit position.

The rotation of the main shaft 68 is accompanied by a corresponding rotation of the Geneva driver arms 207. They rotate to the position shown in FIGURE 9 and move the main Geneva roller 210 further into the slot 226. This causes the main Geneva cam 225 to rotate through 12 to effect a corresponding rotation of the second switch crank 67.. The first 9 of this rotation effects rotation of the second switch blade 37 about its longitudinal axis to the position shown by full lines in FIGURE 4 which is the unlocked position. Continued rotation of the second switch blade 37 about its longitudinal axis causes it to rotate out of high pressure contact engagement with the second line contact member 31. At the time that the contacts of the load current interrupter 80 are opened to interrupt the circuit the sequence of operation is such that the second switch blade 37 still is in high pressure contact engagement with the second line contact member 31. It is only after the circuit has been interrupted by the load current interrupter 80 that the second switch blade 37 is moved out of high pressure contact engagement with the second line contact member 31.

The rotation of the main shaft 68 continues through an additional 54% or through a total of 113 from the initial position. During this rotation the push bolt 188 engages the shoulder 189 on the operating spring arm 139 and thereby rotates the interrupter trip actuator 182 for the purpose of tensioning or re-cocking the

springs

167 and 168. During the final portion of the rotation of the main shaft 68 through the 113, the first switch crank 66 is similarly rotated to the position shown by the dot and dash lines in FIGURE 4. This is accompanied by a swinging of the first switch blade 35 about 14 the axis of the pivot 40 to a position at right angles to the position which it occupies in the circuit closed position.

During this further rotation of the interrupter trip actuator 182, the roller 192 moves out of engagement with the arm 196 and the spring 202 then urges the interrupter closing lever 152 to the position shown in FIG- URE 10 of the drawings where the roller 149 carried thereby engages an abutment 227 that extends inwardly from the mechanism housing 43.

FIGURE 10 of the drawings shows the arm 187 on the interrupter trip actuator 182 rotated through the full extent of rotation of the main shaft 68 with the push bolt 188 engaging the shoulder 189 on the operat ing spring arm 139. There has been a corresponding rotation of the pair of Geneva driver arms 207 and the main Geneva roller 210 in the radial slot portion 226 rotates the main Geneva cam 225 through an additional 72 for a total of to effect a corresponding rotation of the second switch crank 67 to the position shown by the dot and dash lines in FIGURE 4. There is a corresponding rotation of the second switch blade 37 to the open position which is at right angles to its closed position. When the switch construction shown in FIGURE 1 is in the open position, the first and

second switch blades

35 and 37 extend upwardly in parallel relation to each other from the mechanism housing 43. There is then an air gap between the mechanism housing 43 and the second line contact member 31 while a high resistance circuit exists between the first line contact member 29 and the mechanism housing 43 through the voltage distributing resistors 117. As the second switch blade 37 leaves the arcing horns 34, a very low current arc is drawn in interrupting the current flow through the voltage distributing resistors 117.

The switch construction now is in the open position. As pointed out, the first and

second switch blades

35 and 37 are in upstanding parallel relation and at right angles to their closed circuit positions. The contact tips 101 of the interrupter units 81 are out of engagement with the respective contact fingers 90. The voltage distributing resistors 117 are in series and individually in parallel circuit relation with the respective open contacts of the interrupter units 81. The

springs

167 and 168 are re-cocked and the trip latch 172 engages the shoulder of the trip cam 169. It remains to describe the sequence of operation for closing the switch construction to reestablish the circuit.

The sequence of closing the switch construction is first to close the second switch blade, thereby again placing the voltage distributing resistors 117 in the circuit, next completing the circuit by closing the first switch blade 35 and finally closing the contacts of the load current interrupter 80 in parallel with the first switch blade 35. To eifect this operation the arm 28, FIG- URE 3, is rotated to rotate the arm 20 and the intermediate insulator 18 in a clockwise direction. This effects a corresponding rotation of the main shaft 68. The Geneva drive arms 20-7, FIGURE 10, rotate in a clockwise direction to effect a rotation of the main Geneva cam 225 in a counterclockwise direction. This is accomplished through the movement of the main Geneva roller 210 in the radial slot portion 226 to rotate the auxiliary shaft 69 and therewith the second switch crank 67. This causes the second switch blade 37 to rotate about the pivot 57 from the vertical position toward the closed position. The rotation of the main shaft 68 is accompanied by rotation of the interrupter trip actuator 182 in a clockwise direction together with the roller 192 which moves toward the arm 196 which is associated with the interrupter closing lever 152.

The first switch crank 66 also rotates in a clockwise direction together with the main shaft 68 to rotate the first switch blade 35 from the open position toward the closed position.