US3671689A

US3671689A - Disconnect switch

Info

Publication number: US3671689A
Application number: US104579A
Authority: US
Inventors: Vincent G Falvo
Original assignee: McGraw Edison Co
Current assignee: Cooper Industries LLC
Priority date: 1971-01-07
Filing date: 1971-01-07
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

A disconnect switch is disclosed which may be mounted in a vertical or underhung position and operated from below. The disconnect switch includes a switch blade having a pivoting end and a laterally extending lever arm at the pivoting end. A toggle linkage operating mechanism is positioned opposite the lever arm in a direction away from the switch blade. When the disconnect switch is positioned vertically, the toggle linkage will be below the switch blade. The toggle linkage is connected between the lever arm and a fixed terminal pad and has an operating arm integral with the toggle link connected to the lever arm and extending away from the toggle linkage. The operating arm is rotatable by a hook stick about the knee of the toggle linkage and about the lever arm to pivot the switch blade between a closed and open position with a fixed contact.

Description

United States Patent Falvo [52] US. Cl. ..200/48 A, 200/ l 66, 200/ l 70 [5 l] Int. Cl. ..I-I0lh 31/00 [58] Field oi Search ..200/48 A, 48 R, 166, I66 A,

200/166 R, 170 A, l7l R, 172 B, l62, I530 [56] References Cited UNITED STATES PATENTS 2,575,707 I 1/1951 Gilliland et al ..200/48 A 2,466,374 4/1949 Caldwell et al. ..200/48 A 51 June 20, 1972 Primary E\'aminer-Herman .l. Hohauser Attorney-Richard C. Ruppin [57] ABSTRACT A disconnect switch is disclosed which may be mounted in a vertical or underhung position and operated from below. The disconnect switch includes a switch blade having a pivoting end and a laterally extending lever arm at the pivoting end. A toggle linkage operating mechanism is positioned opposite the lever arm in a direction away from the switch blade. When the disconnect switch is positioned vertically. the toggle linkage will be below the switch blade. The toggle linkage is connected between the lever arm and a fixed terminal pad and has an operating arm integral with the toggle link connected to the lever arm and extending away from the toggle linkage. The operating arm is rotatable by a hook stick about the knee of the toggle linkage and about the lever arm to pivot the switch blade between a closed and open position with a fixed contact.

6 Claims, 3 Drawing Figures P'A'TENTEDauneo m2 WNW.

ali

DISCONNECT SWITCH BACKGROUND OF THE INVENTION This invention relates to a switch mechanism and, more particularly, to a disconnect switch which can be operated from below. The invention has particular, but not exclusive, application to electrical power systems wherein relatively high current levels are carried.

Disconnect switches are widely used in electrical power systems for isolating portions of the system. The disconnect switches are typically located at positions elevated relativeto persons working in the area of the switches. For this reason, operation of the switches is facilitated if they may be operated from a position below their locations. Also, the switches are usually manually operated so that the operating mechanism must conveniently be suitable for operation by manual means such as a hook stick.

SUMMARY OF THE INVENTION It is accordingly a general object of the invention to provide a disconnect switch which can be readily operated from a position below its location by manual means. More specific objects of the invention include the provision of a switch having a simple operating mechanism which applies a great amount of switch opening and closing force relative to the force applied to the operating mechanism.

The objects of the invention are accomplished by providing a switch having a switch blade pivotally mounted on one end and a lever arm integral with the switch blade extending laterally from the pivoted end. A toggle linkage mechanism is connected between the lever arm and a fixed terminal upon which the switch blade is also pivoted. The toggle linkage mechanism is positioned opposite the lever arm of the switch blade in a direction away from the switch blade. Where the switch is disposed vertically, the toggle linkage operating mechanism is positioned below the switch blade so that it is accessible from below. The toggle link which is pivotally connected to the lever arm includes an integral operating arm extending away from the toggle linkage mechanism. The operating arm may be rotated about the knee of the toggle linkage and about the pivot point on the operating arm by manual means to provide opening and closing force through the lever arm of both the toggle linkage and the integral lever arm of the switch blade. The force applied by both of these lever arms is a maximum when the switch blade is near its closed position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an elevational view of a switch according to the instant invention in a closed position;

FIG. 2 shows an elevational view of the switch of FIG. 1 in an open position; and

FIG. 3 shows an elevational view of the switch of FIG. 1 in a position adjacent the closed position of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring generally to the drawings, a disconnect switch is shown having

terminals

2 and 12, switch arm 30, and toggle linkage operating mechanism 50. The terminals 2and 12 are both suitable for mounting on a base or wall (not shown). The, terminal 2 includes an insulator 4, a contact portion 6 and a break jaw 8. The break jaw 8 comprises

fingers

10a, 10b, 10c and 10d for snugly receiving and holding the switch arm 30. The fingers 10c and 10d are behind the

fingers

10a and 10b in the drawings and are not shown. The terminal 12 includesinsulator l4 and a terminal pad 16. The terminal pad 16 has an ear 18 extending away from the back member 20 and insulator 14. The switch arm includes an elongated switch blade 32 having an end 34 movable into engagement with break jaw 8. The blade 32 also has an end 36 pivotally mounted at 38 on the ear 18 of terminal pad 16. The blade 32 has a coating of a highly conductive material such as' metalized silver positioned circumferencially about the pivot point 38 in engagement with the ear 18. Thus, thereis a continuous electrical circuit from the terminal 2 to the terminal 12 when the blade 32 is in;engagement with thebreak jaw 8 through break jaw 8, blade 32, coating 40 and terminal pad 16. The switch arm 30 also includes a leverarm 42 extending away from the end 36 and terminal 12 and having an end 44 and an edge 64.

The disconnect switch includes a toggle linkage mechanism 50 for applying opening and closing force to the switch arm 30 to pivot it to its open and closed position as respectively shown on FIGS. 2 and l. The toggle linkage 50 includes a link 52, pivotally connected'to the lever arm 42 at 46 and a link 54 pivotally connected at 48 to the ear 18 of terminal pad 16. The toggle linkage 50 has aknee 56 at which the

links

52 and 54 are pivotally connected together. The link 52 includes an integral or unitary operating arm 58 extending away from the

links

52 and 54. and having an opening 60 adjacent to the extended end. A retaining spring 62 is provided at the knee 56 to prevent'the links 52 and from pivoting about pivot point 48 dueto their own weight.

InFIG. l, the disconnect switch is shown in a closed position inwhich the

links

52 and 54 are extended to a substantially alignedposition and are-slightly overset toward the ter minal pad 16. The knee 56 thus engages the car 18 to prevent collapse of the toggle linkage 50 and the oversetting of the

links

52 and 54 prevents the switch arm from opening during momentary current surge conditions.

The disconnect switch is shown in its open position in FIG. 2 in which the

toggle links

52 and 54 are collapsed. In order to move the switch arm 30 from the closed position to the open position, theoperating arm 58 is rotated about the knee 56 and the pivot point 46 on lever arm 42 of switch arm 30. Opening rotational movement is in the clockwise direction and closing rotation is in the counter-clockwise direction, relative to the views shown in FIGS. 1, 2 and 3. The rotational force. can be applied by means such as a hook stick which can be connected to the opening 60 on operating arm 58. A particularly large leverage advantage is available for opening and closing the switch arm 30 when it is near the break jaw 8, as shown in FIG. 3, due to the simultaneous effect of both the toggle linkage 50 and the lever arm 42. This leverage is large when the switch is near the closed position because the leverage of toggle linkage 50 is near maximum and simultaneously the lever arm distance between pivot 38 and the link 52 which is applying force to lever arm 42 is near maximum. This enables a forceful and quick opening and closing movement on'the switch arm 30 as it is moved into and out of the break jaw 8. It is noted that providing a link 52 having the integral or unitary operating arm 58 provides a simple means for applying opening and closing force to both the toggle linkage 50 and the lever arm 42 so that the above advantage can be obtained.

The positioning of the toggle linkage 50 opposite the edge 64 of lever arm 42 and away from the switch blade 32 also assists in obtaining the above described leverage advantage and provides a compact structure in which the toggle linkage 50 and the projecting operating arm 58 are readily accessible for opening and closingoperation. The position of the toggle linkage 50 and the operating arm 58 relative to the switch arm 30=is particularly advantageous in disconnect switch applications, where, it is desirable to operate the disconnect switch from below.

While only the preferred embodiment of the invention has been shown herein, it will be realized that many modifications thereof are feasible without departing from the spirit and scope of the invention. For example, the switch arm 30 may include a fuse as an integral part of the arm. It is accordingly intended that the scope of the invention is not to be limited to the specific embodiment disclosed.

Iclaim:

I. A disconnect switch having first and second terminals, and, switch arm means for electrically connecting said terminals, said switch arm means being electrically connected to said first terminal and having aclosed position electrically engaging saidsecond terminal and'an open position, said switch arm means including a blade having a length, an end pivotally mounted on the first terminal and a lever arm adjacent and integral with said end and projecting away from the end and said first terminal, and a toggle linkage comprising a first toggle link pivotally mounted on the first terminal at a position spaced from the end of said blade in a direction parallel to the length of said blade when the switch arm means is in said closed position, a second toggle link pivotally mounted on said lever arm at a position spaced from the end of said blade, said toggle linkage having a knee at which said first and second toggle links are pivotally connected, said first and second toggle links being novable between a substantially aligned position in which the switch blade is in said closed position and a collapsed position in which said switch blade is in an open position.

2. The combination according to claim 1 wherein said toggle linkage is adjacent said aligned position and said second toggle link is simultaneously at a right angle to a line between the end of said switch blade and the pivotal mounting position of the second toggle link on the lever arrn whereby maximum force is applied to said switch blade when it is adjacent said closed position.

3. The combination according to claim 2 further comprising an operating arm extending away from said knee, said second toggle link and operating arm being a unitary member.

4. The combination according to claim 2 wherein said toggle linkage has an overset condition when said links are substantially aligned, said knee engaging said first terminal to hold the toggle linkage in the overset condition.

5. The combination according to claim 4 wherein each of said terminals includes an insulating bushing and a conductive member mounted on the bushing.

6. The combination according to claim 4 wherein said switch arm means includes a fuse and said switch blade has first and second blade portions attached to opposite ends of the fuse, said second blade portion engaging the second terminal when the switch arm means is in the closed position and said first blade portion being pivotally mounted on the first terminal.

Claims

1. A disconnect switch having first and second terminals, and switch arm means for electrically connecting said terminals, said switch arm means being electrically connected to said first terminal and having a closed position electrically engaging said second terminal and an open position, said switch arm means including a blade having a length, an end pivotally mounted on the first terminal and a lever arm adjacent and integral with said end and projecting away from the end and said first terminal, and a toggle linkage comprising a first toggle link pivotally mounted on the first terminal at a position spaced from the end of said blade in a direction parallel to the length of said blade when the switch arm means is in said closed position, a second toggle link pivotally mounted on said lever arm at a position spaced from the end of said blade, said toggle linkage having a knee at which said first and second toggle links are pivotally connected, said first and second toggle links being novable between a substantially aligned position in which the switch blade is in said closed position and a collapsed position in which said switch blade is in an open position.

2. The combination according to claim 1 wherein said toggle linkage is adjacent said aligned position and said second toggle link is simultaneously at a right angle to a line between the end of said switch blade and the pivotal mounting position of the second toggle link on the lever arm whereby maximum force is applied to said switch blade when it is adjacent said closed position.