US2883484A - Enclosed electric switch - Google Patents

Description

'4 Sheets-Sheet 1 43 Fig. 6

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April 21, 1959 Filed Dec. 4, 1957 F ig.l

April 21, 1959 T. F. BROWN ENCLOSED ELECTRIC SWITCH 4 Sheets-Sheet 2 Filed Dec. 4, 1957 3 IIT 7 1/711 April 21, 1959 T. F. BROWN 2,883,484

ENCLOSED ELECTRIC SWITCH Filed D60. 4, 1957 v 4 Sheets-Sheet 3 April 21, 1959 T. F. BROWN ENCLOSED ELECTRIC SWITCH 4 Sheets-Sheet 4 Filed Dec. 4, 1957 United States Patent ENCLOSED ELECTRIC SWITCH Thomas F. Brown, Belleville, N.J., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 4, 1957, Serial No. 700,635

Claims. (Cl. 200-50) This invention relates, generally, to enclosed electric switches and, more particularly, to enclosed switches having a relatively high current rating which are suitable for utilization in panelboard and switchboard structures.

In order to protect the apparatus and the operating personnel, manually operable circuit interrupters, such as circuit breakers and switches, (are enclosed in metal boxes or cabinets which may be mounted in .a panelboard or in :a switchboard structure. An external handle on the cover of the cabinet drives an operating mechanism, mounted on the inside of the cover, which engages the actuating handle of the circuit interrupter when the cover is closed. The operating mechanism on the cover is disengaged from the interrupter handle when the cover is opened.

In multi-pole switches the movable contact members for .all poles may be actuated by a cross bar or shaft which is driven by a toggle mechanism the actuating handle of which is engaged by the operating mechanism on the cover of the cabinet. Since the toggle mechanism has usually been a part of one of the poles of the switch and electrically energized, the actuating handle has been composed of .an insulating material to protect the :operating personnel. Operating mechanisms of various types have been provided with a view to precluding the possibility of breaking the insulating handle.

An object of this invention is to provide a switch actuating mechanism which is electrically deenergized, thereby making it unnecessary to utilize an insulating handle on the mechanism.

A further object of the invention is to provide a plurality of toggle mechanism which cooperate in operating a multi-pole switch, thereby reducing the size of the individual parts of the toggle mechanisms.

Another object of the invention is to provide for so interconnecting a plurality of toggle mechanisms for actuating a multi-pole switch that the mechanisms may be readily assembled in the switch structure.

A still further object of the invention is to provide an enclosed switch to which power conductors may be readily connected from either the front or the rear of the switch.

Still another object of the invention is to provide a simplified interlocking device for an enclosed switch.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of the invention, the contact arms of a three-pole switch are attached to an insulated cross bar. A toggle mechanism is disposed between each outside pole and the middle pole, thereby keeping these mechanisms electrically deenergized. The operating arms of the toggle mechanisms are also attached to the cross bar and they are pivotally mounted in frame members attached to the base of the switch, thereby actuating the cross bar to actuate the contact arms. The two toggle mechanisms are connected in parallel by a metal tie bar which is attached to the mechanisms after they are assembled in the switch. An actuating handle 2,883,484 Patented Apr. 21, 1959 on the tie bar is engaged by an operating mechanism on the cover when the cover is closed. An interlocking bracket on the tie bar is moved to a position where it is engaged by an interlocking latch on the cover to normally prevent opening the cover when the contact members of the switch are closed. An external handle on the cover drives the operating mechanism on the inside of the cover, thereby operating the toggle mechanisms to actuate the contact arms of the switch.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the ac companying drawings, in which:

Figure 1 is a reduced view, in front elevation, of a panelboard containing switch units embodying the principal features of the invention;

Fig. 2 is a reduced view, partly in section and partly in side elevation, of one of the switch units;

Fig. 3 is a view, in plan, :of the main base assembly of the switch unit;

Fig. 4 is a view, in side elevation, of the main base assembly;

Fig. 5 is a view, in plan, of the switch operating mechanism which is mounted on the inside of the cover of the enclosure for the switch;

Fig. 6 is a detail view, in plan, of one of the toggle mechanisms utilized in the switch; and

Fig. 7 is a detail view, in elevation, of the toggle mechanism shown in Fig. 6.

Referring to the drawings, and particularly to Fig. 1, the structure shown therein comprises a panelboard housing 10 in which is mounted a plurality of switch units 11, 12, 13 and 14. The switch units are of different sizes and ratings, the units 11 being of a relative small current rating, the unit 12 being of a higher rating, and the units 13 and 14 being of still higher ratings. In this application the unit 14, which is the largest unit, is described. One of the smaller units 11 is described in my copending application Serial No. 702,029, filed December 11, 1957.

As shown in Fig. 2, the cabinet 14 which contains the switch assembly has an openable cover 15 which provides access to the switch assembly. An external operating handle 16 is rotatably mounted on the cover 15. A spring-biased latch 17 is provided for retaining the cover 15 closed. As will be described more fully hereinafter, an interlocking device is also provided for normally retaining the cover 15 closed when the contact members of the switch are closed.

Each switch assembly comprises a main base 18 and a secondary or fuse base 19 which is spaced from the main base 18 in the cabinet 14. Line terminal members 21, contact members or fingers 22, arc extinguishers 23 and actuating mechanisms 24 for a three-pole switch are mounted on the main base 18. A fuse terminal 25 and a fuse clip 26 for each pole are also mounted on the base 18. Another fuse clip 27 and a load terminal connector 28 for each pole are mounted on the secondary base 19. The bases 18 and 19 are preferably molded from a suitable insulating material.

As shown more clearly in Figs. 3 and 4, each pole of the switch structure comprises a line terminal assembly which includes the terminal 21, a fixed contact member 21, which may be brazed to the terminal 21, the movable contact member or finger 22, which is carried by a contact arm 31, and a flexible conductor 32 which connects the contact finger 22 to the fuse terminal 25.

The contact finger 22 for each pole is pivotally attached to the contact arm 31 by means of an adjustable screw 33 which is threaded into the contact arm 31. The lower end of the screw 33 has a ball and socket connection with the contact finger 22, thereby permitting the finger 22 to move relative to the contact arm 31. A lock nut 34 is provided on the adjustable screw 33.

A compression spring 35 is disposed between the contact finger 22 and the contact arm 31. The upper end of the spring 35 is disposed in a cup washer 36 which is attached to the contact arm 31, thereby retaining the spring 35 in place.

The contact arm 31 is attached to a cross bar 37 by means of a generally U-shaped staple 38. The cross bar 37 is covered with an insulating material 39, thereby insulating the contact arms for the three poles of the switch from each other. An electrical circuit is established between the terminal member 21 and the fuse clips 26 when the contact members 22 and 21 are engaged. A fuse (not shown) may be inserted in the fuse clips 26 and 27, thereby completing the circuit through each pole of the switch.

As shown most clearly in Fig. 3, the present switch is provided with two toggle mechanisms 24 which cooperate in operating the switch. One toggle mechanism is disposed between each outside pole and the center pole of the switch, thereby keeping the operating mechanisms electrically deenergized at all times. The two toggle mechanisms are connected in parallel by means of a tie-bar 40 as will be described more fully hereinafter.

As shown more clearly in Figs. 4, 6 and 7, each toggle mechanism is disposed between the legs of a generally U-shaped frame member 41, which is attached to the base 1%. The upper ends of the legs of the frame member 41 are secured together at the right-hand side, as viewed in Fig. 4, by a pin 42 and at the left-hand side by a bar 43 which is attached to the frame member 41 by screws 44.

A cradle member 45 is disposed between the legs of the frame member 41 in a fixed position. One end of the cradle member is attached to the pin 42. The other end of the cradle member is anchored underneath the bar 43.

Toggle links 46 are pivotally connected to the cradle member 45 by a pin 47. A toggle link 48 is pivotally connected to an operating arm 49 by means of a pin 51. The toggle links 46 and 48 are pivotally connected together by a toggle pin 52. The operating arm 49 is pivotally mounted in the frame member 41 by means of pins 53. The operating arms for both toggle mechanisms are connected to the cross bar 37 by means of staples 38 in the same manner that the contact arms 31 are connected to the cross bar. As shown in Fig. 3, the contact arm 31 for each outer pole is pivotally supported by a bracket 54 attached to the base 18 by screws 55.

The lower ends of the legs of a generally U-shaped operating lever 56, which is inverted, are pivotally mounted on pins 57 in the legs of the frame member 41. Overcenter toggle springs 58 are connected between the toggle pin 52 and the base of the U-shaped operating lever 56. A connecting member 59 is provided in the lower end of each spring for connecting it to the toggle pin 52. Another connecting member 59 is provided in the upper end of each spring. The upper connecting members 59 are attached to the operating lever 56 by means of pins 61.

As explained hereinbefore, the two toggle mechanisms are connected in parallel by means of the metal tie-bar 40. The bar 44} is removably attached to the operating levers 56 of the two toggle mechanisms by means of bolts 62 and nuts 63 which are threaded onto the bolts 62. The lower end of each bolt 62 is pressed into one of the operating levers 56. Thus, each toggle mechanism may be completely assembled in the switch structure prior to the attaching of the tie-bar 40, thereby facilitating the assembling of the operating mechanism. An actuating handle 64 is secured to the tie-bar 40 by means of rivets 65 as shown in Fig. 3. An interlocking bracket 66 is attached to the tie-bar 46 by means of one of the bolts 62. The function of the interlocking bracket 66 will be described more fully hereinafter.

In order to provide for operating the switch by means of the external handle 16, a cam-shaped plate 71 is attached to the inner end of a shaft of the handle 16 which extends through the cover 15. The plate attached to the shaft by means of a screw '70. The plate 71 carries a pin or anti-friction roller 72 which is disposed in a slot '73 in a slidable operating plate '74. The plate 74 is supported between grooved studs 75 and '76.

As described in my aforesaid copending application, the studs 75 are attached to a supporting plate 77 which, in turn, is attached to the inside of the cover 15 by screws 73. The studs 76 are attached to a second supporting plate 75 which is attached to the first supporting plate and the cover 15 by screws 81. The position of the plate 79 may be varied since additional holes are provided in the cover for the screws 81. Thus the position of the studs 76 may be changed to permit operating plates of different sizes to be utilized for switches of difierent ratings. In the present instance, the operating plate 74 is of a wider size since the present switch has a relatively high current rating, thereby requiring a heavier and stronger operating mechanism. A generally channel-shaped handle engaging plate 82 is attached to the slidable operating plate 74.

The plate 82 has a rectangular opening 83 therein for receiving the actuating handle 64 of the tie-bar 44). Since the operating mechanism in the present switch is electrically deenergized at all times, it is not necessary to provide an insulating actuating handle for the operating mechanisms, and the present handle 64 is composed of metal. Therefore, the handle engaging member 82 may be composed of metal since the problem of breaking the actuating handle 64 is not involved in the present switch structure.

As shown in Fig. 2, the handle 64 is disposed in the opening 83 in the handle engaging member 82 when the cover 15 is fully closed. Thus, rotation of the handle 16 rotates the cam-shaped plate 71 which reciprocates the plate 74 and the handle engaging plate 82 by means of the pin and slot connection 72-73. The plate 82 engages the actuating handle 64 to actuate the contact arms of the switch through the toggle mechanisms 24 and the cross bar 37. Since two toggle mechanisms are provided, the individual parts of each mechanism are not required to be of an excessive size in order to provide for transmitting the force required for actuating the contact members of the switch which are relatively large in size since the present switch is of a relatively high current rating.

In order to normally prevent opening the cover 15 while the contact members of the switch are closed, an interlocking latch 85 is pivotally attached to the cover 15 by means of a screw 86, the head of which is disposed on the outside of the cover. The interlocking latch 85 is biased by a spring 87 to engage the interlocking bracket 66 attached to the tie-bar 40. As shown by the broken lines in Fig. 2, the interlocking bracket 66 is actuated to a position in which it is engaged by a hook portion 88 of the interlocking latch 85 when the contact members of the switch are closed.

In this manner, the cover 15 is normally retained closed while the contact members of the switch are closed. However, the interlocking latch 85 may be actuated by means of the screw 86, to which the latch 85 is attached, to release the latch 85 from the interlocking bracket 66 while the contact members of the switch are closed, thereby permitting access to the inside of the switch cabinet by a person who knows the function of the screw 86.

The mounting of the interlocking bracket 66 on the tiebar 46 of the switch mechanism has the advantage of placing the bracket 66 in a position where it may be engaged by the hook portion 88 of the interlocking latch 85 which is similar in construction to the interlocking device utilized in switches of diflerent current ratings from the present switch. Thus, the interlocking member and certain of the operating members of the mechanism may be of the same construction for a complete line of switches of different current ratings.

As shown in Fig. 2, the line terminal members 21 of the present switch may be connected to power conductors disposed at the rear of the cabinet 14 or to power conductors which enter the cabinet through openings provided in the end of the cabinet. A conducting and spacing member 91 extends through an opening in the base 18 and is attached to the terminal member 21 by a bolt 92. A power conductor 93 is attached to the lower end of the member 91 by the bolt 92. Thus, the present switch unit may be mounted on a switchboard or other structure requiring that power connections be made from the rear of the structure. If it is desired to make the power connections from the front of the structure, terminal connectors 94 of a type similar to the connectors 28 utilized in the load end of the switch may be attached to the terminal members 21, as shown by the broken lines, thereby permitting power conductors to be attached from the front of the structure.

If it is desired to make connections to the load terminal of the switch from the rear of a switchboard structure, a power conductor 94 may be attached to each load terminal member 95 by means of a screw 96. Thus, the switch unit may be utilized in either front or rear connected structures.

From the foregoing description, it is apparent that the present invention provides a switch unit capable of carrying relatively large amounts of current and suitable for use on relatively high voltages. The operating mechanism is electrically deenergized at all times, thereby increasing the safety of the switch unit. Furthermore, breakage of the operating parts of the switch unit is precluded since it is not necessary to make these parts of insulating material. The size and weight of certain of the operating parts are reduced by connecting two of the toggle mechanisms in parallel. The toggle mechanisms may be readily assembled in the switch structure since the tie-bar for connecting the two mechanisms together may be installed after the mechanisms are assembled. The present switch unit is suitable for utilization in either front or rear connected panelboard or switchboard structures.

Since numerous changes may be made in the abovedescribed construction and different embodiments of the invention may be made without departing from the spirit and 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.

I claim as my invention:

1. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, at least two toggle mechanisms attached to the cross bar between said contact arms, said toggle mechanisms being electrically deenergized, a tie-bar connecting said toggle mechanisms to actuate them simultaneously, an operating mechanism mounted on the inside of the cover for engaging said tie-bar when the cover is closed, and an external handle on the cover for driving the operating mechanism to actuate the contact arms.

2. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, a cross bar rotatably mounted, on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation and electrically insulated from each other, at least two toggle mechanisms attached to the cross bar between said contact arms, said toggle mechanisms being electrically deenergized, a metal tie-bar connecting said toggle mechanisms to actuate them simultaneously, an operating mechanism mounted on the inside of the cover for engaging said tie-bar when the cover is closed, and an external handle on the cover for driving the operating mechanism to actuate the cross bar by means of the toggle mechanisms thereby actuating the contact arms.

3. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, at least two toggle mechanisms attached to the cross bar between said contact arms, said toggle mechanisms being electrically deenergized, a tie-bar connecting said toggle mechanisms to actuate them simultaneously, an operating mechanism mounted on the inside of the cover for engaging said tie-bar when the cover is closed, an external handle on the cover for driving the operating mechanism to actuate the contact arms, an interlocking bracket movable with the tie-bar, and an interlocking latch on the cover for engaging said interlocking bracket to retain the cover closed when the circuit interrupter is closed.

4. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, a cross bar rotatably mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation and electrically insulated from each other, at least two toggle mechanisms attached to the cross bar between said contact arms, said toggle mechanisms being electrically deenergized, a metal tie-bar connecting said toggle mechanisms to actuate them simultaneously, an operating mechar nism mounted on the inside of the cover for engaging said tie-bar when the cover is closed, an external handle on the cover for driving the operating mechanism to actuate the cross bar by means of the toggle mechanisms thereby actuating the contact arms, an interlocking bracket attached to the tie-bar, and an interlocking latch movably mounted on the cover for engaging said interlocking bracket to retain the cover closed when the circuit interrupter is closed.

5. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, at least two toggle mechanisms attached to the cross bar between said contact arms, each toggle mechanism having a frame attached to said base and an inverted generally U-shaped operating lever having legs pivoted in said frame, a tie-bar removably attached to the bases of said levers to connect them together after the toggle mechanisms are assembled in the interrupter, an operating mechanism mounted on the inside of the cover for engaging said tie-bar when the cover is closed, and an external handle on the cover for driving the operating mechanism to operate the toggle mechanisms thereby actuating the contact arms.

6. In a multi-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, at least two toggle mechanisms attached to the cross bar between said contact arms, each toggle mechanism having a frame attached to said base and an inverted generally U-shaped operating lever having legs pivoted in said frame, a tie-bar removably attached to the bases of said levers to connect them together after the toggle mechanisms are assembled in the interrupter, an actuating handle on the tie-bar, an operating mechanism mounted on the inside of the cover for engaging said actuating handle when the cover is closed, and an external handle on the cover for driving the operating mechanism to operate the toggle mechanisms thereby actuating the contact arms.

7. In an enclosed circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted at the rear of the cabinet opposite said cover, a terminal member attached to the front side of said base, a fixed contact member on said terminal member, a movable contact member for engaging the fixed contact member, actuating means mounted on the base for actuating the movable contact member, conducting means extending from the rear of the terminal member through said base for making an electrical connection to the terminal member from the rear of the cabinet, and the front of the terminal member being available for receiving a terminal connector to make an electrical connection to the terminal member.

8. In an enclosed circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted at the rear of the cabinet opposite said cover, a terminal member attached to the front side of said base, a fixed contact member on said terminal member, a movable contact member for engaging the fixed contact member, actuating means mounted on the base for actuating the movable contact member, a spacing member attached to the rear of the terminal member and extending through said base and the rear Wall of the cabinet for electrically connecting a conductor to the terminal member, and the front of the terminal member also being available for connecting a conductor to the terminal member.

9. In a three-pole circuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, a toggle mechanism attached to the cross bar between each outside contact arm and the middle contact arm to keep the toggle mechanisms electrically deenergized, a tie-bar connecting the toggle mechanisms to actuate them simultaneously, an actuating handle on the tie-bar, an operating plate slidably mounted on the inside of the cover for engaging said handle when the cover is closed, and an external handle on the cover for reciprocating the operating plate to actuate the contact arms by means of the toggle mechanisms and the cross bar.

10. In a three-pole ciucuit interrupter, in combination, a cabinet having an openable cover, an insulating base mounted in the cabinet, an insulated cross bar pivotally mounted on the base, a contact arm for each pole, said contact arms being attached to the cross bar in spaced relation, a toggle mechanism disposed between each out side contact arm and the middle contact arm to keep the toggle mechanisms electrically deenergized, each toggle mechanism having an operating arm attached to said cross bar to actuate the cross bar, a metal tie-bar connecting the toggle mechanisms to actuate them simultaneously, an actuating handle on the tie-bar, an operating plate slidably mounted on the inside of the cover for engaging said handle when the cover is closed, and an external handle on the cover for reciprocating the operating plate to actuate the contact arms by means of the toggle mechanisms and the cross bar.

References Cited in the file of this patent UNITED STATES PATENTS 2,067,935 Lingal .Tan. 19, 1937 2,325,697 Millermaster et al. Aug. 3, 1943 2,381,848 Van Valkenburg Aug. 7, 1945 2,383,296 Dorfman Aug. 21, 1945

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