US3525831A

US3525831A - Operating mechanism for electric switch

Info

Publication number: US3525831A
Application number: US747041A
Authority: US
Inventors: Raymond J Spisak; Robert A Roach
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1968-07-03
Filing date: 1968-07-03
Publication date: 1970-08-25
Anticipated expiration: 1987-08-25

Description

Aug. 25, 1970 sp s ET AL 3,525,831

OPERATING MECHANISM FOR ELECTRIC SWITCH Original Filed Jan. 27, 1967 2 Sheets-Sheet 1 soc uo o LQ 62- FIG.2.

a 38 38A 36 I g 2Q 62 jijm 44A 1k r-m2 44 12- I 66 1 2| I FIG. I.

' i 26 32 -23 I 1 s1 1 Aug. 25, 1970 s ls ET AL 3,525,831

OPERATING MECHANISM FOR ELECTRIC SWITCH Original Filed Jan. 27, 1967 2 .SheetsS'neet 2 FIGS.

FIG.4.

United States Patent 3,525,831 OPERATING MECHANISM FOR ELECTRIC SWITCH Raymond J. Spisak, East Pittsburgh, and Robert A. Roach, Canonsburg, Pa., assignors to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Continuation of application Ser. No. 612,121, Jan. 27, 1967. This application July 3, 1968, Ser. No. 747,041 Int. Cl. H01h 31/00 U.S. Cl. 20048 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to disconnecting switches and, more particularly, to operating mechanisms for such switches. More specifically, this invention relates to a disconnecting switch construction in which a pair of stationary contacts are spaced from one another along a line which defines a firs-t axis and mounted on only two insulator supports or stacks which are fixedly mounted on a common support base and which are disposed generally perpendicular to the first axis. A switch blade is provided which lies along the first axis and which engages both stationary contacts when the disconnecting switch is closed. To permit opening and closing of the switch, one of the stationary contacts is mounted on a supporting frame which, in turn, is mounted on one of the insulator supports and which rotatably supports a hinge member through which one end of the blade passes and which is rotatable about a second axis which intersects and is perpendicular to the first axis. To actuate the blade, a connecting link is provided which includes a first portion that is secured to the end of the blade which passes through the hinge member and includes an arm which projects away from the first portion at an angle of 45 with respect to the first axis. To actuate the connecting link, a crank member is provided which is rotatable about a third axis that intersects the first and second axes and which includes a tubular bearing portion that rotatably receives the arm of the connecting link. The crank member, in turn, is secured to an electrically insulating operating rod or shaft which passes through a central opening in the insulator support on which the frame is mounted and includes a crank arm which may be driven by an external means to actuate the blade between open and closed positions.

This application is a continuation of application Ser. No. 612,121, filed Jan. 27, 1967, now abandoned and assigned to the same assignee as this application.

In the construction of certain known types of disconnecting switches, such as disclosed in copending application Ser. No. 588,530 which was filed Oct. '21, 196 6 by C. W. Upton, Ir., which issued I an. 30, 1968, as US. Pat. 3,366,753 and which is assigned to the same assignee as the present application, a movable switch blade is actuated to engage and disengage a pair of associated spaced main stationary contacts or break jaws at the opposite ends of the switch blade during the opening and closing of the switch. Each pole unit of a disconnecting switch structure of the type disclosed in the copending application just mentioned requires three insulator supports or stacks which are mounted on and spaced along the common support base with the intermediate insulator stack being rotatable to actuate the associated switch blade between open and closed positions with respect to the spaced stationary contacts generally in a plane which passes through the three insulator stacks required. A disconnecting switch of this general type has the advantage that if the three pole units of a three-phase disconnecting switch are disposed in side-by-side relation, the lateral spacing between the pole units is less than that which would be required if the pole units were of the sidebreak type. It has been found that a disconnecting switch construction of the type described which requires three insulator stacks per pole unit increases the overall size of a disconnecting switch for a particular voltage rating, even though the required lateral spacing between pole units is less than that required for disconnecting switches of the side-break type. The overall size of a disconnecting switch of the type described is particularly important where the switch is to be applied in a substation which is located in a highly congested urban area where space is at a premium. It is therefore desirable to provide an improved, more compact disconnecting switch structure which requires only two insulator stacks per pole unit and which provides switch blade movement generally in a plane which passes through the insulator stacks of each pole unit.

It is an object of this invention to provide a new and improved disconnecting switch structure.

Another object of this invention is to provide a more compact disconnecting switch structure.

A further object of this invention is to provide an improved disconnecting switch structure requiring only two insulator supports or stacks per pole unit.

A more specific object of this invention is to provide an improved disconnecting switch structure requiring only two insulator supports or stacks per pole unit and including means for actuating a movable blade substantially in the plane in which the insulator supports lie.

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

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side elevational view of a disconnecting switch structure embodying the principal features of the invention, with the switch structure shown in the closed circuit position;

FIG. 2 is a top plan view of the disconnecting switch structure shown in FIG. 1;

FIG. 3 is a view, partly a top plan view and partly in section, of a portion of the disconnecting switch structure shown in FIGS. 1 and 2 illustrating the position of certain parts after the switch blade of the disconnecting switch structure has been actuated to the open position;

FIG. 4 is a view, partly in side elevation and partly in section, of a portion of the disconnecting switch structure shown in FIGS. 1 and 2 with the movable blade of the disconnecting switch structure shown in the closed position; and

FIG. 5 is a view, partly in side elevation and partly in section, of the portion of the disconnecting switch structure shown in FIG, 3 with the movable blade of the disconnecting switch structure shown in the open position.

Referring now to the drawings and FIGS. 1 and 2 in particular, there is shown a disconnecting switch assembly 10 which comprises two spaced insulator stacks or supports 21 and 22 mounted upon a common base support 32. The base 32 is preferably a metal channel having flanges which extend outwardly from the sides of the channel. Each of the insulator stacks 21 and 22 comprises a plurality of insulators which are preferably formed from porcelain or a similar material having sufficient structural strength to support the operating parts of the disconnecting switch assembly 10. The number of insulators required in each of the

insulator stacks

21 and 22 depends upon the voltage of the system in which the disconnecting switch 10 is applied. The insulator stack 22 is mounted upon a fixed pedestal or spacer 23 which, in turn, may be secured to the top of the base 32 by suitable means, such as bolts. The insulator stack 21 is generally tubular in configuration and includes a central opening 21A, as shown in FIGS. 4 and 5, through which an electrically insulating rod or shaft 52 passes for a purpose which will be explained hereinafter. The insulator stack 21 is mounted upon a fixed, generallly tubular bracket 26, as shown in FIG. 1, which, in turn, may be secured to the top of the base 32. In order to permit the passage of the operating rod 52 through the bracket 26 and the base 32, the bracket 26 and the base 32 include openings therethrough which are substantially aligned with each other and with the central opening 21A of the insulator stack 21. An operating lever or crank arm 82 may be secured to the shaft 52 to rotate the operating rod or shaft 52 during the operation of the disconnecting switch 10, as will be explained hereinafter.

The disconnecting switch includes a first generally U-shaped main stationary contact assembly or break jaw assembly which is mounted on and secured to the top of the insulator stack 22, as shown in FIGS. 1 and 2. The stationary contact assembly 20 includes a pair of spaced contact jaws 36 which are interconnected by a base portion or bight portion that is secured to the top of the insulator stack 22 by suitable means, such as bolts. A terminal pad 44 which is adapted to receive a terminal connector is also secured to the top of the insulator stack 22 and includes a vertical extension 44A which may be formed integrally therewith and which acts as a stop for the movement of the associated switch blade 38 into engagement with the contact jaws 36. In addition, a stationary arcing horn (not shown) may be also secured to the top of the insulator stack 22, as disclosed in the copending application of C. W. Upton, Jr. previously mentioned.

The contact jaws 36 are of the reverse loop type which have the characteristic of magnetically forcing the associated switch blade 38 downwardly, as viewed in FIG. 1, between the break jaws 36 in a direction toward the base portion which interconnects the contact jaws 36 and against the blade stop 44A when a relatively high momentary current flows through the disconnecting switch 10. The contact jaws 36 are preferably formed from a suitable material which combines relatively high electrical conductivity with excellent spring characteristics, such as zirconium copper or cadmium chrome copper. The resilient nature of the contact jaws 36 substantially eliminates the need for additional spring or biasing means to bias the contact jaws 36 toward one another for gripping the free end of the associated switch blade 38 when the switch blade 38 is actuated to engage the contact jaws 36 to insure adequate contact pressure.

The disconnecting switch 10 also includes a second main stationary contact assembly 30 which is mounted on a generally U-shaped stationary support frame 110 which, in turn, is mounted on top of and secured to the insulator stack 21, more specifically to an end cap 66 which is mounted at the upper end of the insulator stack 21 by suitable means, such as a plurality of bolts 122, which pass through associated openings in the base portion 116 of the support frame 110 and engage internally threaded openings provided in the end cap 66, as best shown in FIGS. 3 and 4. The support frame 110 is formed or cast from a suitable material which comprises relatively high electrical conductivity with suflicient structural strength to rotatably support the associated switch blade 38, such as an aluminum bronze alloy. As illustrated in FIGS. 3 and 4, the support frame 110 includes a pair of laterally spaced generally parallel

side wall portions

112 and 114 which are interconnected by the base or bight portion 116 of the support frame 110 and includes an end wall portion 118 which projects upwardly from the base portion 116 at an oblique angle with respect to the base portion 116 and extends laterally between the 4.

side wall portions

112 and 114. The support frame also includes a terminal pad 62 which may be formed integrally with the end wall portion 118 and which is adapted to receive a terminal connector. The second main stationary contact assembly or main hinge contact assembly 30 includes a pair of spaced contact jaws 54 which are interconnected by a base portion or bight portion that is secured to the end wall portion 118 of the support frame 110 by suitable means, such as the bolts 56 shown in FIG. 4. Similarly to the contact jaws 36, the contact jaws 54 are preferably formed from a suitable material which combines relatively high electrical conductivity with excellent spring or resilient characteristics, such as the materials previously mentioned to eliminate the need for additional spring means or biasing means to bias the contact jaws 54 toward one another to provide sufiicient contact pressure with the adjacent end of the associated switch blade 38 when the switch blade 38 engages the contact jaws 54.

In order to electrically bridge the spaced main

stationary contact assemblies

20 and 30 just described when the disconnecting switch 10 is in the closed position shown in FIGS. 1 and 2, the movable switch blade 38 is disposed to engage both of the

stationary contact assemblies

20 and 30 when the disconnecting switch 10 is in the closed circuit condition shown in FIGS. 1 and 2 along a line or axis which extends between the

contact assemblies

20 and 30. As illustrated, the switch blade 38is generally tubular in configuration with the opposite ends being shaped to provide high pressure contact areas which engage the associated

contact jaws

36 and 54 of the

contact assemblies

20 and 30, respectively. More specifically, the right end of the switch blade 38, as indicated at 38A in FIGS. 1 and 2, may be flattened to be generally rectangular in cross-section, while the other end of the switch blade 38, as indicated at 38B, may include a pair of raised or rib portions (not shown) at the opposite sides of the switch blade 38 to engage the associated contact jaws 54 at the left end of the switch blade 38, as viewed in FIGS. 1 and 2. In order to facilitate the interruption of magnetizing or charging currents during the opening of the disconnecting switch 10, a movable arcing horn (not shown) may be mounted at the free end of the blade 38 to cooperate with a stationary arcing arm (not shown) during such an opening operation, as disclosed in the copending application previously mentioned.

In order to support the switch blade 38 for rotation about its own axis and for arcuate movement about an axis which extends generally transversely with respect to the axis of the switch blade 38, the spaced

side wall portions

112 and 114 of the support frame 110 are disposed on opposite sides of the left end of the switch blade 38, as viewed in FIGS. 1 and 2. As best shown in FIGS. 2 and 3, a hinge member 60 is pivotally supported between the

side wall portions

112 and 114 of the support frame 110 by the bolts 158 which pass through substantially aligned openings provided in the

side wall portions

112 and 114 and the

arms

60B and 60C of the hinge member 60 which project laterally from the opposite sides of a central tubular portion 60A of the hinge member 60. The left end of the switch blade 38, as viewed in FIG. 4, is disposed to pass through the central tubular portion 60A of the hinge member 60 to engage the associated contact assembly 30 when the disconnecting switch 10 is in the closed position shown in FIGS. 1, 2 and 4. It is to be noted that the hinge member 60 is rotatable about an axis which extends through the bolts 158, as viewed in FIG. 3, and which intersects both the axis of the switch blade 38 and a line which extends between the

stationary contacts

20 and 30 at substantially a right angle.

In order to actuate the switch blade 38 between open and closed positions with respect to the associated

contact assemblies

20 and 30, a connecting link member 50 is secured to the switch blade 38 for movement therewith. In particular, the connecting link 50 includes a first portion 50A which is secured to the switch blade 38 adjacent to the end which passes through the hinge member 60 by suitable means, such as the bolt 63, which passes through aligned openings in the first portion 50A of the connecting link 50 and the switch blade 38. The first portion 50A of the connecting link 50 which is generally tubular in configuration includes a flange portion 50D which is located intermediate the ends of the first portion 50A. Part of the first portion 50A of the connecting link 50 which extends axially to the right from the flange portion 50D, as viewed in FIG. 4, is concentrically disposed between the hinge member 60 and the switch blade 38 and projects axially along the switch blade 38 to the right of the hinge member 60, as viewed in FIG. 4. In order to rotatably support the switch blade 38 along with the first portion 50A of the connecting link 50 in the central tubular portion 60A of the hinge member 60, the flanged

sleeve bearing members

102 and 104 are disposed be tween the first portion 50A of the connecting link 50 and the central tubular portion 60A of the hinge member 60, as shown in FIG. 4. The flanged

sleeve bearing members

102 and 104 are axially spaced from one another along the switch blade 38 and are formed from a suitable material, such as bronze, which is coated with a material having a relatively low coeflicient of friction, such as the material polytetrafluoroethylene which is sold under the trademark Teflon. The bearing

members

102 and 104 are maintained in assembled relationship with the associated hinge member 60 and the connecting link 50 by the flange portion 50D which is provided on the first portion 50A of the connecting link 50 and the retaining ring 106 which is disposed in a groove provided adjacent to the right end of the portion 50A of the connecting link 50 on the other side of the central tubular portion 60A of the hinge member 60. The connecting link 50 is also provided with an arm portion 50B which is generally tubular in configuration and which projects from the first portion 50A of the connecting link 50 at an angle of substantially 45 with respect to the longitudinal axis of the switch blade 38 and with respect to the line which extends between the stationary contact assemblies and 30. The axis of the arm portion 50B of the connecting link 50 also intersects the axis of rotation of the switch blade 38 which extends between the bolts 158, as previously described.

In order to actuate the arm portion 50B of the connecting link 50 and, in turn, to actuate the movement of the switch blade 38, the crank member 70 is mounted on and secured to the electrically insulating operating rod or shaft 52, as shown in FIGS. 1 and 4, by suitable means such as the bolts 152. The crank member 70 includes a base portion 70A and a generally tubular bearing portion 70C which is connected to the bearing portion 70A by an upwardly extending web portion 70B and which is adapted to receive the arm portion 50B of the connecting link 50. In order to rotatably support the connecting link 50 in the bearing portion 700 of the crank member 70, a pair of flanged

sleeve bearing members

126 and 128 are disposed at the opposite ends of the bearing portion 70C of the crank member 70 between the arm portion 50B of the connecting link 50 and the inner surface of the bearing portion 70C of the crank member 70. In order to maintain the bearing

members

126 and 128 in assembled relationship with the associated arm portion 50B of the connecting link 50 and the bearing portion 70C of the crank member 70, the flange portion 50C is provided on the arm portion 50B of the connecting link 50 and a retaining ring 127 is disposed on the lower end of the arm portion 50B of the connecting link 50 in a groove provided adjacent to the lower end of the arm portion 50B. It is to be noted that the crank member 70 is rotatable with the operating rod or shaft 52 about an axis which is substantially coincident with the longitudinal axis of the insulator stack 21. It is also to be noted that the axis of rotation of the crank member 70 substantially intersects the longitudinal axis of the switch blade 38, the axis of rotation of the hinge member 60, and the axis of rotation of the arm portion 508 of the connecting link 50. As previously mentioned, the axis of rotation of the arm portion 50B of the connecting link 50 intersects the longitudinal axis of the switch blade 38 at an angle of substantially 45 with respect to the axis of the switch blade 38 and also intersects the axis of rotation of the crank member 70 at an angle of substantially 45 with respect to the axis of rotation of the crank member 70, as best illustrated in FIG. 4.

In order to limit the arcuate travel or movement of the switch blade 38 from the closed position shown in FIGS. 1 and 2 to the open position which is angularly displaced from the closed position shown in FIG. 1 by an angle of substantially about the axis of rotation of the hinge member 60, a stop member 132 is mounted on the "base portion 70A of the crank member 70 and may be formed integrally therewith to engage the lower end 38B of the switch blade 38, as viewed in FIG. 5, when the switch blade 38 is actuated to the open position.

In order to assist the actuation of the switch blade 38 from the open position shown in FIGS. 3 and 5 to the closed position shown in FIGS. 1, 2 and 4, the cam member or projecting portion 70D, as shown in FIG. 3, is mounted on or formed integrally with the bearing portion 70C of the crank member 70 and is disposed to engage one end of the arm 60D which extends from a flange portion 60E on the hinge member 60 toward the contact assembly 30 and, more particularly, toward the contact jaws 54, as illustrated in FIG. 4. It has been found that when the switch blade 38 is in the open position shown in FIGS. 3 and 5, the mechanical advantage of the hinged conducting structure just described is substantially at a minimum. When the disconnecting switch 10 is actuated from the open position in which the switch blade 38 is disposed generally vertically, as viewed in FIG. 5, the cam portion 70D on the crank member 70 engages the arm 60D on the hinge member 60 from about 10 to 20 of the approximate 90 of rotation required of the operating rod or shaft 52 during the actuation of the switch blade 38 from the open position shown in FIGS. 3 and 5 to the closed position shown in FIGS. 1, 2 and 4 to transmit a driving torque to the switch blade 38 directly from the crank member 70 to the hinge member 60 and the switch blade 38 to assist in actuating the movement of the switch blade 38 during the portion of the movement of the switch blade when the mechanical advantage of the hinge conducting structure described is substantially at a minimum.

In order to maintain a continuous conducting path between the switch blade 38 and the conducting frame support during the opening movement-of the switch blade 38, a conducting member (not shown) may be disposed generally concentrically between the tubular portion 60A of the hinge member 60 and the first tubular portion 50A of the connecting link 50 as described in greater detail in the copending application previously mentioned to engage both the inner surface of the central portion 60A of the hinge member 60 and the outer surface of the first portion 50A of the connecting link 50 at a plurality of points to prevent any burning or arcing at the hinged conducting structure of the disconnecting switch 10 previously described.

In order to actuate the movement of the switch blade 38, the operating rod or shaft 52 is disposed to pass through the aligned openings provided in the base 32, the bracket 26 and the insulator stack 21 and is secured adjacent to its upper end to the crank member 70, as previously described. As best shown in FIG. 4, a flanged sleeve bearing 72 may be disposed between the upper end of the operating rod 52 and the end cap 66 around the opening 66A provided in the end cap 66 with the base portion 70A of the crank member 70 resting or bearing on the flange portion of the bearing 72, as shown in FIG. 4.

A flanged sleeve bearing 37 may also be provided adjacent to the lower end of the insulator stack 21 between the operating rod 52 and the bracket 26 around a central opening provided in the bracket 26 to assist in guiding the rotation of the operating rod 52. As previously mentioned, the operating rod 52 is formed from an electrically insulating material having sufficient strength to transmit the driving torque from whatever external operating mechanism (not shown) is provided to the switch blade 38 to the crank member 70 and the connecting link 50, such as a glass reinforced polyester or melamine material.

In the overall operation of the disconnecting switch 10, when the operating rod or shaft 52 is rotated by an external operating mechanism or means (not shown) through the crank member or operating lever 82, from the position of the operating rod 52 which corresponds to the position of the crank arm 82 shown in solid lines in FIG. 2 to the position of the operating rod 52 which corresponds to the position of the crank arm indicated in phantom at 82' in FIG. 2, the switch blade 38 is first actuated through the crank member 70 and the connecting link 50, as guided by the hinge member 60, to rotate about its own longitudinal axis. During the initial rotation of the crank arm 82 in a clockwise direction, as viewed in FIG. 2, from the position indicated in solid lines, the switch blade 38 rotates about its own longitudinal axis until the contact pressure between the contact surfaces provided at the free end or portion 38A of the switch blade 38 is reduced or relieved. Simultaneously or subsequently during the rotation of the crank arm 82 and the corresponding rotation of the operating rod 52, the switch blade 38 is rotated in an arcuate path about the axis which extends through the bolts 158 from the closed position shown in FIGS. 1 and 2 to the open position which is shown in FIGS. 3 and 5 and which is displaced from the closed position by an angle of substantially 90 in a clockwise direction, as viewed in FIG. 1. During the opening movement of the switch blade from the closed position shown in FIGS. 1 and 2 to the open position shown in FIGS. 3 and 5, both ends of the switch blade 38 will be disengaged from the associated

contact assemblies

20 and 30 and after the left end of the switch blade 38 as viewed in FIGS. 1 and 2 is disengaged from the contact assembly 30, the conducting member (not shown) which is described in the copending application previously mentioned maintains an electrically conducting path from the switch blade 38 to the electrically conducting frame support 110 to prevent arcing or pitting of the hinged conducting structure provided in the disconnecting switch which would otherwise result due to the interruption of an electrically conducting path through the moving parts of the disconnecting switch 10. As previously mentioned, the stop member 132 provided on the base portion 70A of the crank member 70 limits the arcuate or rotational travel of the switch blade 38 from the closed position shown in FIGS. 1 and 2 to the open position shown in FIGS. 3 and 5. It is important to note that the arcuate travel or movement of the switch blade 38 as described is generally in a plane which passes through both of the insulator stacks 21 and 22 and which is generally perpendicular to the axis of rotation of the hinge member 60 which extends through the bolts 158.

In a closing operation of the disconnecting switch 10, the operating rod 52 is rotated through the crank member or operating lever 82 from the position which corresponds to the position of the crank arm indicated in phantom at 82' in FIG. 2 to the position indicated in solid lines in FIG. 2 at 82 to thereby actuate the switch blade 38 from the open position shown in FIGS. 3 and 5 through the crank member 70 and the conducting link 50, as guided by the hinge member 60, to the closed position shown in FIGS. 1 and 2. As previously mentioned, during the initial rotation of the operating rod 52 from the position which corresponds to the position of the operating lever indicated at 82' in FIG. 2, the arm 60D provided on the hinge member 60 is engaged by the cam surface 70D provided on the bearing portion 700 of the crank member 70 as shown in FIG. 3 to actuate the switch blade 38 initially from the open position when the mechanical advantage of the drive system which includes the operating rod 52, the crank member 70, the connecting link 50 and the hinge member 60 is substantially at a minimum to insure proper operation of the disconnecting switch 10 during the closing of the disconnecting switch 10. It has been found that the driving torque or force exerted on a switch blade 38 through the cam 70 and the arm 60D of the hinge member 60 is effective during a closing operation of the switch blade 38 from about 10 to 20 of the initial rotation of the operating rod 52 from the position which corresponds to the position of the operating lever as indicated at 82' in FIG. 2 toward the position of the operating rod 52 which corresponds to the position of the operating lever 82, as shown in solid lines in FIG. 2. It is to be noted that during the final movement of the switch blade 38 to the closed position shown in FIGS. 1 and 2, the blade 38 is rotated about its own axis to facilitate the entrance of the blade 38 between the contact jaws 36 and then to insure adequate contact pressure between the contact surfaces at each end of the blade 38 and the associated

contact jaws

36 and 54.

It is to be noted that the conducting path through the disconnecting switch 10 when the disconnecting switch 10 is in the closed position shown in FIGS. 1 and 2 extends from the terminal pad 44 at the right end of the switch 10, through the contact jaws 36, the contact portion 38A of the switch blade 38, the main body of the switch blade 38, the contact jaws 54 of the stationary contact assembly 30 to the electrically conducting frame support and finally to the terminal pad 62 at the left end of the disconnecting switch 10, as viewed in FIGS. 1 and 2.

The apparatus embodying the teachings of this invention has several advantages. For example, in a disconnecting switch as disclosed, only two insulator stacks or supports are required for each pole unit of the disconnecting switch. In addition, the required length of each pole unit in a disconnecting switch as disclosed is reduced to thereby reduce the overall size of the disconnecting switch because of the reduction of the required size of the hinge support. A further advantage of a disconnecting switch as disclosed is that the arcuate movement of the switch blade of each pole unit lies substantially in a plane in which the associated insulator supports of each pole unit are disposed to thereby reduce the required lateral spacing between adjacent pole units of a three-phase disconnecting switch assembly compared with the spacing required in disconnecting switches of the side-break type.

Since numerous changes may be made in the above described apparatus and dilferent embodiments of the invention may be made without departing from the spiritand scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. A disconnecting switch comprising an elongated base, a pair of spaced, generally parallel, elongated insulator supports both fixedly secured to said base, an electrically conducting member supported on one of said insulator supports adjacent to one end thereof, a switch blade movably supported on the other of said insulator supports to engage said conducting member when the switch is closed, said other of said insulator supports having a central opening which extends axially therethrough, and an electrically insulating operating rod disposed to pass through the central opening of said other of said insulating supports, said operating rod being operatively connected to said switch blade and means for rotatably supporting said operating rod within said central opening.

2. The combination as claimed in claim 1 wherein the last-mentioned means comprises first and second bearing means which are mounted at the opposite ends of said other of said insulating supports to assist in rotatably supporting said operating rod within the opening of said other of said insulating supports.

3. A disconnecting switch comprising a pair of stationary contact members disposed in spaced relation along a first axis, an elongated base, a switch blade disposed generally along the first axis to engage both of said contact members when the switch is closed, one of said contact members being mounted on a first insulator support, the other of said contact members being mounted on a conducting frame disposed adjacent to one end of the blade, said frame being mounted on and secured to a second insulator support having a central opening which extends axially therethrough, said first and second insulator supports being both fixedly secured to said base and disposed generally perpendicular to the first axis, a conducting hinge member having a generally tubular portion and being pivotally supported on the frame for rotation about a second axis which intersects the first axis at substantially a right angle, said one end of the blade being disposed to pass through and being radially spaced from the tubular portion of the hinge member, a connecting link secured to the blade adjacent to said one end and having a first portion rotatably disposed between the blade and the tubular portion of the hinge member and an arm projecting away from the first portion at an angle of substantially 45 with respect to the first axis, a crank member rotatable about a third axis which substantially intersects said first and second axes and having a generally tubular bearing portion adapted to rotatably receive the arm of the connecting link, an electrically insulating operating rod disposed to pass axially through the central opening of the second insulator support, said crank member being secured to said rod for rotation therewith, and first and second bearing means mounted at the opposite ends of said second insulator support to rotatably support said operating rod within the opening of said second insulator support.

4. The combination as claimed in claim 3 wherein the stationary contact mounted on the first insulator support comprises a pair of reversed loop members for holding the other end of the blade in an engaged position by the magnetic forces which result when relatively high momentary currents fiow through the switch.

5. The combination as claimed in claim 3 wherein the conducting frame includes a pair of spaced side Wall portions which rotatably support the conducting hinge member at the opposite sides thereof.

6. The combination as claimed in claim 3 wherein both of the stationary contact members are generally U-shaped in configuration with the opposite ends of the blade which engage the stationary contact members being shaped to provide high pressure contact areas.

7. The combination as claimed in claim 6 wherein the conducting frame includes a pair of spaced side wall portions which rotatably support the conducting hinge member at the opposite sides thereof.

References Cited UNITED STATES PATENTS 2,791,651 5/1957 OrtWig 20048 3,005,063 10/1961 Zemels et al 200-48 3,240,887 3/ 1966 Melbye. 3,243,561 3/1966 Foti.

ROBERT K. SCHAEFER, Primary Examiner H. I. HOHAUSER, Assistant Examiner