US3041419A

US3041419A - Disconnecting switch

Info

Publication number: US3041419A
Application number: US754040A
Authority: US
Inventors: Richard F Gibbons; David L Hughes
Original assignee: Federal Pacific Electric Co
Current assignee: Federal Pacific Electric Co
Priority date: 1958-08-08
Filing date: 1958-08-08
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26

Description

June 26, 1962 R. F. GIBBONS ET AL 3, ,4 9

DISCONNECTING SWITCH Filed Aug. s, 1958 2 Sheets-Sheet 1 P INVENTORS law/22p F; c/gzoA/s 34w: 4. Has/M's -.05 Wwra;

ATTO R N EY United States Saratoga, Electric Company, a

The present invention relates generally to a disconnecting switch and, more particularly, to a disconnecting switch of the type having flattened end portions or contact inserts that are adapted to be turned about the longitudinal axis of the switch blade to bring such end portions or inserts into high pressure contact making engagement with companion stationary contacts.

The primary aim and object of the present invention is the provision of an improved operating mechanism for a disconnecting switch of the aforementioned character in which the circuit opening and closing movements of the switch blade and the contact pressure producing rotary movements thereof are eifected in a simple, unique and highly etficient manner. Pursuant to this object of the present invention the switch blade is pivotally movable in a horizontal plane between circuit open and circuit closed positions with respectto the stationary contact means, all of the rotary movement of the switch blade about its longitudinal axis occurring prior to any pivotal circuit opening movement thereof and subsequent to any pivotal circuit closing movement thereof. This rotary movement may conveniently be referred toas twisting and this pivotal movement may conveniently be called swinging.

Yet another object of the present invention is the provision of an improved operating mechanism for a disconnecting switch as aforenoted in which the operating mechanism includes motion transmitting means that is simple in design and construction utilizing a mini-mum number of parts, and foolproof in operation.

In the art to which our present invention relates there are disconnecting switches of the double side break type in which the stationary contacts are mounted on a pair of stationary insulator columns with the switch blade being mounted on a center rotating insulator column, this type switch having the attendant disadvantages of the requirement of heavy anti-friction bearings for the rotating insulator column and complexity of operating mechanism. The disconnecting switch of the present invention obviates these disadvantages by providing for the rotation of the switch blade on a center stationary insulator column with rotation being imparted to the switch blade by a relatively light rotatable insulator stack disposed adjacent the center column, said stack being driven by the group operating mechanism and providing a high ratio of mechanical advantage for the mechanically balanced double-break switch blades and the operating mechanism which is supported on the center insulator column.

Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when considered in connection with the accompanying drawings in which:

FIG. 1 is a top plan view of a single-pole disconnecting switch formed according to the present invention with the switch blade shown in solid lines in contact making engagement with the stationary contacts;

FIG. 2 is a front view thereof;

FIG. 3 is a fragmentary end view showing in solid lines one end of the switch blade in contacting engagement with its companion stationary contact;

FIG. 4 is a sectional view, on an enlarged scale, taken on the line 4-4 of FIG. 1;

FIG. 5 is a sectional view, on an enlarged scale, taken on the line 55 of FIG. 1;

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FIG. 6 is a fragmentary enlarged front view showing the switch blade partially rotated about the axis thereof;

FIG. 7 is a view similar to FIG. 6 showing the switch blade operating mechanism in position to commence the swinging movement of the switch blade; and

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 2.

Referring to the drawings in detail, there is ShOVW'l a disconnect switch 10 which is of the general type shown in Patent No. 2,328,171 issued on August 31, 1943 to Schwager et a1., and assigned to the assignee herein. The switch 10 is of the double side break type and is mounted on three aligned

stationary insulator columns

12, 14 and 16 which are carried by a base support 18 which in turn may be mounted on the cross arm of a pole or a part of a transmission line supporting tower. The insulator columns 12 and 16 carry stationary contacts 20 and 22, respectively, each of which is provided with a terminal 24. The contacts 20 and 22 are disposed in opposite directions as shown in FIGS. 1 and 2, each of said con tacts being mounted on a laterally extending arm 26 and comprising a laterally spaced pair of

resilient contact arms

28 and 30 having outwardly bowed free or leading end portions 32. It will be understood that the contacts 20 and 22 may be of any suitable design and construc tion and the particular construction herein shown and described is given by way of example only. Disposed between the contact arms and laterally projecting from spacer 34 is a stop member 36 which is formed of a suitable insulating material.

The center insulator column 14 forms a mounting for the switch blade 38 and the operating mechanism to be described in detail hereinafter which provides the swinging and rotary movement of the switch blade. The switch blade 38 is journalled for swinging or pivotal movement on column 14, the latter having at its upper end a hollow shaft or fitting 40 with stub shaft 4-2 being rotatably mounted therein. The shaft 42 is provided with a collar 44 seated on the end of shaft 40. The switch blade comprises a hollow shaft 46 and sleeve 48, the stub shaft 42 depending from said sleeve. The sleeve 48 is longitudinally apertured therethrough as indicated at 50' for the extension therethrough of shaft 46, the latter being rotatable about its longitudinal axis in said sleeve in the circuit closed position of the switch blade. The shaft 46 is secured against axial displacement in the sleeve by the

' stop sleeves

52 and 54 which are suitably secured to said shaft. The opposite ends of the shaft 46 of the switch blade are provided with diametrically opposed flattened portions or contact inserts 56 which engage between

companion contact arms

28 and 30 when the switch blade is in contact making engagement with contacts 20 and 22.

The switch blade 38 is mounted for swinging movement in a horizontal plane between circuit open position as indicated in broken lines at 38' in FIG. 1 and circuit closed position as shown in solid lines in said figure, said switch blade in said circuit closed position being rotatable into and out of contact making engagement with the stationary contacts 20 and 22. The operating mechanism for swinging and rotating the switch blade will now be described.

Mounted on the support 18 adjacent column 14 is a gearbox 58 having a worm 60 and worm wheel 62. The

group control shaft 64 is connected to the worm 60 to I0 tate the latter. The relatively light rotatable insulator stack 70 is disposed adjacent the center insulator column post 76 to limit the rotation of stack 70, the shoulder aligned with the ball and socket connection.

78 limiting rotation of stack 70 in a circuit open direction and the shoulder 78' limiting rotation of stack 7% in a circuit closed direction. Suitably mounted on column 14 adjacent the top thereof is a stationary bracket 80 which rotatably mounts the shaft 82 (FIG. the latter having a bevel gear 84 secured thereto which is in mesh with the bevel gear 86 secured at the upper end of stack 70. The bracket 89 is cutaway at the top thereof as indicated at 81 to provide clearance for the switch blade in the circuit closed position thereof. The stack 79' is supported for rotation at its upper end by the depending bracket part 88 of bracket 80. It will be noted that shaft 82 extends transversely at an acute angle with respect to the switch arm in the circuit closed position thereof and is inclined downwardly with respect to the horizontal towards the geared end thereof. The opposite end of shaft 82 has a crank arm 90 secured thereto for movement thereby, said crank arm having an inwardly bent end part 92 provided with a ball fitting 94. The ball fitting 94 interfits in the socket 96 at the outer end of the pivotally mounted arm 98. The ball and socket fittings are biased into mutual engagement by the spring 100 which is positioned between the ball fitting 94 and the retainer plate 102 which is suitably secured to the arm 98.

Pivotally mounted on the sleeve 52 is a yoke 104, the sleeve 52 having a fitting 106 which mounts the pivot pin 108 of the yoke. Thus the pivot axis of the yoke extends perpendicular to the rotary axis of the switch blade. The opposite end of the yoke pivotally mounts the arm 98, the latter having a fitting 110 which is pivotally mounted to the yoke by the pivot pin 112 whose axis is parallel to the axis of the pivot pin 103. Secured to the sleeve 52 adjacent fitting 110 is a U-shaped bracket 114 having laterally spaced arms 11 6 and 118 disposed at the opposite sides of said fitting. Suitably secured in position between arm 116 and fitting 116 is a compression spring 120 which biases the fitting 110 and the pivotally mounted yoke away from arm 116. The yoke is pivotally movable from a position in engagement with the arm or stop 118 as shown in FIG. 7 to a position adjacent arm or stop 116 in which the spring 120* is under maximum compression, as shown in FIG. 6. In FIGS. 1 and 3, in solid lines, the switch blade is shown in circuit closed position and in contacting engagement with the stationary contacts and in this position the flattened portions or inserts 56 make high pressure engagement with the

contact arms

28 and 30; In this position a circuit is completed between the terminals 24 and the switch blade abuts the stop members 36. In this position also the post 76 coacts with the shoulder 78' to define the extreme position in a circuit closed direction.

To open the disconnecting switch and thereby open the circuit between the terminals 24, the group control shaft 64 is rotated counterclockwise (FIG. 2) in a circuit opening direction to correspondingly actuate crank arm 90 to rotate the portions 56 out of contact making engagement with the stationary contacts and sequentially thereafter to swing the switch blade away from said contacts to a circuit open position, the maximum circuit open position being at the point of interengagement of post 76 with shoulder 78. More particularly, the initial rotation of shaft 64 in a circuit opening direction will pivot crank arm 90 in the direction of the arrow shown in FIG. 2 to thereby rotate the yoke 104 and switch blade about the longitudinal axis thereof, the yoke 1M concomitantly pivoting about the pivot axis 108 thereof to the position shown in FIG. 6 in which spring 120 is under maximum compression and in which the pivotal axis of the crank arm 91) and the axis of spring 126 are The continued rotation of the group control shaft will continue the pivotal movement of the crank arm to the position of FIG. 7 to thereby continue to rotate the yoke and switch blade, the yoke 104 concomitantly pivoting about the pivot axis thereof in an opposite direction to the FIG; 7 1

position in which the fitting 11G abuts the stop 118. In this position of the operating mechanism, the switch blade portions 56 will be in the broken line position shown in FIG. 3 and the switch blade will be at the position of maximum rotation out of contact making engagement. The continued rotation of the shaft 64 swings the switch biade 46 about column 14 to a circuit open position. The crank arm 99 and arm 98 in a cycle of operation move in different planes with the ball and socket connection coupling the same for conjoint movement.

To close the switch, the above is reversed in sequence and the group control shaft is rotated to swing the switch blade against stop members 36 to the circuit closed position, the continued rotation of the crank being effective to rotate the switch blade to. bring the portions 56 thereof into high pressure engagement with contact arms 28 and 3t). Said continued rotation will pivotally move the yoke initially towards stop 116 to compress the spring and thereafter the yoke will pivotally move in the opposite direction towards the stop 118, the pivotal movement of the yoke about axis 108 being concomitant with the axial rotation of the yoke and switch blade about the switch blade axis. Thus the yoke and the mounting thereof as aforedescribed provide for the sequential axial rotation and swinging movement of the switch blade. It will be noted that all of the rotary movement of the switch blade occurs prior to any pivotal circuit opening movement thereof and subsequent to any pivotal circuit closing movement thereof. The operating mechanism providing for this sequential operation utilizes a minimum number of component parts and is inherently foolproof in operation and highly efficient in the accomplishment of its intended purposes. The operating mechanism carried by the stationary insulator column 14 is contained in a suitable weatherproof housing, a portion of which is indicated at 66 in FIG. 2.

The linkages of the operating mechanism are positive in operation and no rotary movement of the switch blade can occur until the full pivotal circuit closing cycle of the switch blade is completed whereby to prevent rotary movement of the switch blade in a circuit open position thereof and a switch open condition. The stack 70, which is formed by interconnecting a series of insulator members in end-to-end relation, is driven by the group operating mechanism and provides a high ratio of mechanical advantage for the operating mechanism by providing many stack revolutions for a cycle of operation of the switch blade. This arrangement minimizes the problem and complexity of the anti-friction mounting arrangement that is involved in double-armed disconnect switches of the form having a central supporting insulator that must also be rotated to operate the switch.

As an inherent feature of the switch blade design, the switch blade is self balancing, eliminating the need for counterbalancing. The problem of high maximum bending moments is minimized by the instant support of the switch blade at the center. lnterphase short circuit magnetic forces do not tend to open the switch blade since such forces are balanced out. Single phase short circuit magnetic forces tend to move the switch' blade in a vertical direction and this tendency is counteracted by the side break disposition of the contacts.

It will be understood that switch 10 may be used as a single pole unit or coupled with companion units to form V a multi-pole unit which is actuated by the shaft 64 which is coupled to each of the poles of such multi-pole unit.

While there is shown and described herein certain specific structure embodying the invention it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited insofar as indicated by the scope of the appended Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

l. A disconnect switch, including a pair of stationary contacts, a pair of fixed insulator columns remote from each other carrying said stationary contacts, respectively, a fixed supporting insulator column midway between and aligned with said remote insulator column, a switch blade simultaneously cooperable with said stationary contacts as a bridging connector therebetween, means carried by said supporting insulator column providing swinging and twisting support for said switch blade, an actuating mechanism carried by said supporting insulator column and connected to said blade for swinging said switch blade horizontally" between open circuit position remote from said stationary contacts and closed circuit position at said contacts, said mechanism additionally having means for twisting said blade about its longitudinal axis when in closed position for making and breaking pressure engagement between said blade and said contacts, rmpectively, and an additional insulator column rotatably mounted laterally adjacent said supporting column and having a top rotational bearing mounted on and supported by said supporting insulator column and said additional insulator column being operatively connected to said actuating mechanism.

2. A disconnect switch, including a pair of stationary contacts, a pair of fixed insulator columns remote from each other carrying said stationary contacts, respectively, a fixed supporting insulator column midway between and aligned with said remote insulator columns, a switch blade simultaneously cooperable with said stationary contacts as a bridging connector therebetween, means carried by said supporting insulator column providing swinging and twisting support for said switch blade, an actuating mechanism carried by said supporting insulator column and connected to said blade for swinging said switch blade between open circuit position remote from said stationary contacts and closed circuit position at said contacts, said mechanism additionally having means for twisting said blade about its longitudinal axis when in closed position for making and breaking pressure engagement between said blade and said contacts, respectively, an additional insulator column rotatably mounted laterally adjacent said supporting column, a bracket extending from said supporting column and providing a fixed rotational bearing for said additional insulator column, and gearing connecting said additional insulator column to said actuating mechanism.

3. A disconnect switch, including a pair of stationary contacts, a pair of fixed insulator columns remote from each other carrying said stationary contacts, respectively, a fixed supporting insulator column midway between and aligned with said remote insulator columns, a switch blade simultaneously cooperable with said stationary contacts as a bridging connector therebetween, a limit stop adjacent at least one of said contacts, means carried by said supporting insulator column providing swinging and twisting support for said switch blade, an actuating mechanism carried by said supporting insulator column and connected to said blade for swinging said switch blade between open circuit position remote from said stationary contacts and closed circuit position at said contacts and engaging said limit stop, said actuating mechanism including positive drive connecting means to said blade in the blade opening direction and including resilient connecting means in the direction toward said limit stop, said mechanism additionally having means for twisting said blade about its longitudinal axis when in closed position for making and breaking pressure engagement between said blade and said contacts, respectively, and an additional insulator column rotatably mounted laterally adjacent said supporting column and having rotary bearing support thereon and operatively connected to said actuating mechanism.

4. A disconnect switch including at least one stationary contact, a limit stop associated therewith, an elongated switch blade having a non-round contact portion, a fixed support spaced from said contact and carrying said switch blade, and an actuating linkage on said support for swinging the switch blade into and out of coaction with said stop and for twisting said blade about its longitudinal axis for making and breaking pressure connection to said stationary contact while coacting with said stop, said actuating mechanism including a yoke pivoted to said elongated switch blade and having a pivotal axis at right angles thereto, a pair of stops fixed to said switch blade at longitudinally spaced points at opposite sides of a movable part of said yoke, a linkage operable successively to drive said yoke in a stroke to twist said switch blade and to swing said blade, said linkage causing said yoke to engage one of said pair of stops in the opening operation at an intermediate part of said stroke so as to establish positive drive connection from said yoke to said' switch blade, for eifecting the swinging operation of the switch blade, a compression spring between said yoke and the other of said pair of stops and effective during the reverse operation of said linkage for yieldably driving said switch blade against said =lirnit stop, said linkage being operable to actuate said yoke for twisting the switch blade which is thus firmly biased against said limit stop as it is being twisted, both at the end of the closing operation of the linkage and at the start of the opening operation of the linkage.

5. A disconnect switch including at least one stationary contact, a limit stop associated therewith, an elongated switch blade having a non-round contact portion, a support spaced from said stationary contact and carrying said switch blade, and a drive linkage proportioned for successively swinging the switch blade into coaction with said limit stop and twisting said blade about its longitudinal axis for making and breaking pressure connection between said contact portion and said stationary contact while the switch blade coacts with said limit stop, said linkage including a resilient drive coupling effective in the closing operation of the linkage to yieldably drive said switch blade against said limit stop, said linkage including a positive drive coupling efiective to swing said blade in the opening direction, whereby the blade is firmly biased against said limit stop as it is being twisted at the end of the closing operation of the linkage and at the start of the opening operation of the linkage.

6. A disconnect switch including two widely separated stationary contacts, a limit stop associated with both of said contacts, an elongated switch blade having a nonround contact portion at the extremities thereof, supporting means midway between said contacts and carrying said switch blade, and an actuating linkage for swinging the switch blade into and out of coaction with said limit stops and for twisting said blade about its longitudinal axis for making and breaking pressure connection between said non-round portions and said stationary contacts, respectively, while said blade coacts with said limit stops, said actuating mechanism including a yoke pivoted to said elongated switch blade and having a pivotal axis at right angles thereto, a pair of stops fixed to said switch blade at longitudinally spaced points at opposite sides of a movable part of said yoke, a linkage operable successively to drive said yoke in a stroke to twist said switch blade and to swing said blade during successive portions of the stroke, said linkage causing said yoke to engage one of said pair of stops in the opening operation at an intermediate part of said stroke so as to establish positive drive connection from said yoke to said switch blade, for effecting the swinging operation of the switch blade, a compression spring between said yoke and the other of said pair of stops and effective during the reverse operation of said linkage for yieldably driving said switch blade against said limit stops, said linkage being operable to actuate said yoke for twisting the switch blade which is thus firmly biased against said limit stops as it is being twisted at 7 the end of the closing operation of the linkage and at the start of the opening operation of the linkage.

7. A high-voltage disconnect switch including at least one stationary contact, a limit stop associated therewith, an elongated switch blade having a fish-tail contact engageable with said stationary contact in a twisting motion, supporting an actuating mechanism spaced from said stationary contact and including an actuating linkage for swinging the switch blade into and out of engagement with said limit stop and for twisting said blade about its longitudinal axis for making and breaking pressure connection to said stationary contact while coacting with said stop, said actuating mechanism including a yoke pivoted to said elongated Switchblade and having a pivotal axis at right angles thereto, an operating crank, a rigid-link connection between said crank and said yoke, and a resilient drive connection between said yoke and said blade arranged to transmit actuating effort yieldably from said crank to said blade during the blade-swinging stroke toward the limit stop, said actuating linkage being arranged to apply positive twisting efiort to said blade when in engagement with said limit-stop, said yieldable effort transmitted from said crank to said blade through said resilient drive connection being eifective to swing the blade toward the limit stop from switch-open condition and thereafter to maintain the switch blade against said limit stop both during twist-closing and twist-opening actuation of the elongated switch blade about its axis.

References Cited in the file of this patent UNITED STATES PATENTS 843,070 Button Feb. 5, 1907 1,560,998 Koppitz Nov 10, 1925 2,521,484 Schmidt Sept. 5, 1950 2,602,866 Cole July 8, 1952 2,760,019 Curtis Aug. 21, 1956 2,774,832 Turgeon Dec. 18, 1956 2,779,830 Turner et al Ian. 29, 1957 2 2,816,971 Mayo et a1. Dec. 17, 1957