GB2134716A

GB2134716A - Switch position indicator

Info

Publication number: GB2134716A
Application number: GB08401946A
Authority: GB
Inventors: Shozo Kaneki; Megumu Nakamura
Original assignee: Terasaki Electric Co Ltd
Current assignee: Terasaki Electric Co Ltd
Priority date: 1983-01-28
Filing date: 1984-01-25
Publication date: 1984-08-15
Also published as: FR2540284B1; JPS59139510A; FR2540284A1; BR8400360A; GB2134716B; DE3402691A1; DE3402691C2; GB8401946D0; IT8419345A0; IT1173157B

Abstract

Indicator for electrical switches comprises a spot-faced hole (3) and a throughgoing hole (9) formed in an enclosure (1), a mirror member (17) mounted on the bottom of the spot- faced hole (3), and an indicator member (13) linearly displaceable within the holes (3, 9) with its position depending on the circuit condition of the electrical switch. The mirror member (17) has a mirror surface (19) formed on its outer surface. The inner surface of the indicator member (13) is formed with first visible information. The inner surface of the spot-faced hole (3) is formed with second visible information. Thus, when the indicator member (13) is in the lower end position, the second visible information is reflected by the mirror surface (19) and viewed from the front side of the enclosure (1). On the other hand, when the indicator member (13) is in the upper end position, the first visible information is reflected by the mirror surface (19). <IMAGE>

Description

SPECIFICATION Indicator for electrical switches Background of the invention Field of the invention This invention relates to an indicator for electrical switches. More particularly, it relates to a device for use with electrical switches having an enclosure, such as circuit breakers, for indicating the opened or closed state of the switch or a cause of an automatic circuit breaking action in such a manner that the indication is visible from the front of the enclosure.

Description of the prior art In an electrical switch having an enclosure, it is desirable that only after the opened or closed state of the switch or a cause of an automatic circuit breaking action has been ascertained using an indicator visible from the front of the enclosure and after the cause of the accident has been removed, the operation proceed to the next step. To this end, it is required that the indication be sufficiently clearly visible to make it possible for the operator to avoid misconception and that reliability of indication be high. Further, it is necessary that such indicator be small-sized so that it occupies a small area and a small volume on the surface of theenclosure of the electrical switch.

None of the conventional devices, however, have been designed to meet all the aforesaid requirements.

As disclosed in United States Patent No.

4,166,989 and Japanese Patent Publication No.

25150/1977, for example, a device is known where a window opening is formed so that the indicator plate is directly exposed through said window opening. In this type of conventional device, in order that the indication may be clearly distinguished, the rotary movement of an indicator rod causes the indicator plate to perform an arcuate movement to traverse the window opening. However, the stroke for such arcuate movement is great, so that there has been a disadvantage that the indicator occupies a large space.

Accordingly, an object of this invention is to eliminate the drawbacks of such conventional device and provide an indicator for electrical switches which is small-sized and highly reliable and designed to make the indication clearly visible from a side, e.g., the front of the enclosure.

Summary of the invention The indicator for electrical switches according to this invention may, in brief, be described as being constructed by forming the surface of the enclosure with an opening perpendicular to said surface and providing a mirror surface in the form of the inclined surface of a cone which is fixed in position within said opening so that its apex points to the surface of the enclosure. An indicator member is provided which surrounds the mirror surface and which is linearly displaceable within the opening.Thus, a displacement of the displaceable member which displaces in accordance with the circuit condition of the electrical switch housed in the enclosure is transmitted to the indicator member, so that when the indicator member is positionally associated with the mirror surface in accordance with said displacement, the indicative information formed on the inner peripheral surface thereof becomes visible through the opening.

Accordingly to this invention, the indicator surface is reflected on the mirror surface in the form of a cone and is thereby made visible from the front of the enclosure, with the result that the indication area is large enough to make it possible to clearly ascertain the circuit condition of the electrical switch. Further, it is not necessary to impart a rotary movement to the indicator member, as in the prior art, and instead a linear movement is imparted thereto, so that the space occupied by the indicator is small and, moreover, the change of condition of indication can be clearly indicated even if the mechanical stroke is small. In other words, according to this embodiment, it is not necessary to increase the actuation stroke so much in order to clearly distinguish the change of condition of indication, and in this respect, too, reduction of size is possible.Further, since the mirror surface is in the form of a cone, there is almost no dead angle when the indication is viewed from the front of the enclosure; particularly, such dead angle can be substantially eliminated if the mirror surface is in the form of a circular cone.

In a certain embodiment of this invention, the mirror surface is formed on the outer surface of a cone, but in a more preferable embodiment, it is formed on the inner surface of a conical recess formed in one end of the columnar transparent member. According to this preferable embodiment, there is an advantage that the formation of a mirror surface is relatively simple.

In another preferred embodiment, the mirror surface is integrally fixed on the enclosure, and a plate spring which constitutes a transmission mechanism for transmitting the movement of the displaceable member to the indicator member is substantially fixed on the enclosure. The other end of the plate spring is connected to the indicator member so that a force is applied to the plate spring when the displaceable member is displaced, whereby the indicator member is linearly displaced in the opening. According to this preferred embodiment, not only the mirror surface but also the plate spring (part of the transmission means) can be removably attached to the enclosure and hence the indicator and the mechanism for detecting the circuit condition of the electrical switch can be easily separated.

Thus, there is an advantage that the mounting and dismounting of the indicator for inspection and other purposes is easy and so is assembly.

The aforesaid and other objects and features of the invention will become more apparent from the following detailed description to be given with reference to the drawings.

These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Brief description of the drawings Fig. 1 is an exploded perspective view of the principal portion of an embodiment of this invention; Figs. 2 and 3 are sectional views for explaining the operation of said embodiment; Fig. 4 is an exploded perspective view showing the principal portion of another embodiment of this invention; Figs. 5 and 6 are sectional views for explaining the operation of said embodiment; Fig. 7 is a schematic view showing an example of a switch embodying this invention, Fig. 8 is a partly broken-away side view taken as indicated by the line A-A of Fig. 7 for explaining the operation of the Fig. 7 embodiment; Fig. 9 is a schematic view showing an example of an electrical switch embodying this invention; Fig. 10 is an exploded perspective view of the principal portion of the Fig. 9 embodiment;; Figs. 11 and 12 are partly broken-away side views taken as indicated by the line B-B in Fig. 9 for explaining the operation thereof; Fig. 1 3 is a schematic view showing an example of a circuit breaker embodying this invention; Figs. 14 through 1 7 are views for explaining the arrangement and operation of the circuit breaker shown in Fig. 13, Figs. 15 through 17 being sectional views taken along the line C-C in Fig. 13; Fig. 18 is an exploded perspective view of the principal portion of the Fig. 1 3 embodiment; and Figs. 1 9 and 20 are sectional views taken along the line D-D in Figs. 13 and 14 for explaining the operation of the Fig. 13 embodiment.

Description of the preferred embodiments Fig. 1 is an exploded perspective view of the principal portion of an embodiment of this invention, and Figs. 2 and 3 are sectional views for explaining the operation thereof.

An enclosure 1 for an electrical switch (not shown) is made, e.g. of molded insulator and has a spot-faced hole 3 formed in the outer surface thereof. Part of the spot-faced hole 3 is formed with a throughgoing hole 9 extending through the enclosure 1 for allowing the slide movement of an indicator member 13, i.e., -an actuator rod 1 3a.

That is, the spot-faced hole 3 is formed as an enlarged opening to the throughgoing hole 9. The throughgoing hole, that is, the bottom of the spot faced hole 3 is formed with a mount 7 for mounting a mirror member 17 having a mirror surface 1 9 formed on its outer surface. The region of the enclosure 1 around the end edge of the spot-faced hole 3 is formed with a step 11 in which a transparent window 21 to be later described will be fitted.

The mirror surface 19 is formed as by vapor deposition of aluminum on the inclined surface (outer surface) of the mirror member 17 made, e.g., of synthetic resin. The mirror member 1 7 is fixedly mounted on the mount in such a manner that its conical apex points to the surface of the enclosure 1. In addition, such mirror member 17 is not limited to a circular cone but may be another form of cone, e.g., a pyramid having a polygonal base.

The indicator sleeves 1 3 is formed to surround the mount 7, i.e., the mirror surface 19 of the mirror member 17, the lower end thereof being provided with the actuator rod 1 3a. The actuator rod 1 3a extends through the throughgoing hole 9 into the interior of the enclosure 1. The inner surface of the indicator sleeves 13 is formed with an indicative surface 1 5 including first visible information in the form of a character, figure, sign or color or a combination thereof. In this embodiment, the indicative surface 1 5 is colored red.On the other hand, the inner surface of the spot-faced hole 3 at the position associated with the mirror surface 19 is fixed to the mount 7 is formed with an indicative surface 5 including second visible information in the form of a character, figure, sign or color or a combination thereof. In this embodiment, the indicative surface 5 is colored green.

As shown in Fig. 2, when the indicator member, i.e., the indicator sleeve 13 (actuator rod 1 3a) is in the lower end position, the second visible information, i.e, the green color in this embodiment, included in the indicative surface 5 formed on the inner peripheral surface of the spot-faced hole 3 is reflected by the mirror surface 1 9 and viewed from the front side of the enclosure 1.

When the actuator rod 1 3a is actuated by an unillustrated detection mechanism, the indicator sleeve 1 3 is projected to surround the mirror surface 19, as shown in Fig. 3. In this case, the red color formed on the inner surface of the indicator sleeve 1 3 is reflected by the mirror surface 19 and viewed from the front side of the enclosure 1. Therefore, in this indicator, the green color in the case of Fig. 2 and the red color in the case of Fig. 3 are respectively indicated.

Fig. 4 is an exploded perspective view showing the principal portion of another embodiment of this invention, and Figs. 5 and 6 are sectional views for explaining the operation thereof.

This embodiment differs from the preceding one particularly in the shape of the mirror member 17. That is, the mirror member 1 7 is made entirely of transparent material such as glass or acrylic resin and includes a columnar portion 1 8 and a flange 20 formed on one end of said columnar portion 18. The other end of the columnar portion 18 is formed with a conical recess. The inner surface of the recess is formed with a mirror surface 1 9 as by vapor deposition of aluminum. The formation of the mirror surface 19 on the mirror member 17 of such shape makes it easier to form the mirror surface 19 than in the preceding embodiment. This is because, in vapor deposition of aluminum, the mirror member 1 7 can be held very easily by means of the flange 20.

Further, the flange 20 is secured to the enclosure 1, so that the positioning and fixing of the mirror surface 19 in the through going hole 3 can be easily effected. In the case of this embodiment, the mount 7 serves as a simple stop for the indicator sleeve 13.

The actuator rod 1 3a of the indicator sleeve 1 3 is inserted in the throughgoing hole 9, with the indicator sleeve 13 placed on the mount 7.

Subsequently, the flange 20 of the mirror member 1 7 is fitted in the step 11 to fixedly hold the mirror surface 19 in the throughgoing hole 3. In addition, the columnar portion 1 8 is, of course, of such a size and shape that it can be inserted in the hollow portion of the indicator sleeve 13.

When the actuator rod 1 3a, that is, the indicator sleeve 1 3 is in the lower end position, as shown in Fig. 5, the second information, e.g., green color, included in the second indicative surface 5 formed on the inner peripheral surface of the spot-faced hole 3 is reflected by the mirror surface 19 through the transparent columnar portion 1 8 and is viewed from the front of the enclosure 1. On the other hand, in the case of Fig.

6, the first visible information, e.g., red color, formed on the inner peripheral surface of the indicative surface 13 becomes visible.

Such indicator can be utilized to view from the front of the enclosure the opened or closed condition of an electrical switch, the automatically opened condition of a circuit breaker due to overload, short-circuit or other fault, or the mechanical (positional) condition of an object to be detected such as a current sensor, voltage sensor or relay provided for protecting and monitoring a circuit breaker.

Fig. 7 is a schematic view showing an example of an electrical switch using such indicator, and Fig. 8 is a partly broken-away side view taken as indicated by the line A-A of Fig. 7 for explaining the operation of the device of this embodiment.

The enclosure of an electrical switch 100 comprises a mold cover 101 and a mold base 102, each being made of molded insulator. The mold base 102 of the enclosure is formed with a fixed contact 105, and a movable contact 107 corresonding to said fixed contact 105 is provided. The movable contact 107 is formed on the front end of a movable contact lever 109, which is rotatably supported on a shaft 111 and held by a contact holder 113. The other end of the contact holder 113 is integrally connected to a cross bar 1 17 by a clasp 115 and together with a movable contact lever for the other pole it forms a movable contact assembly.The switch mechanism (not shown) of this movable contact assembly is arranged so that it can be manually moved between the opened and closed position using an operating handle 103 projecting out of the mold cover 101 of the enclosure.

In order to transmit the movement of the movable contact assembly between the opened and closed positions, an actuator plate 121 is connected to one end of a detecting lever 11 9 projecting from the clasp 11 5. The front end of the actuator plate 1 21 is substantially L-shaped to form an abutment surface. The actuator plate 121 is inserted in the throughgoing hole of a guide member 123 integrally formed on the mold base 1 02. Thus, the movement of the movable contact assembly between the opened and closed positions is transmitted to the actuator plate 121 and its bent front end 121 a is vertically displaced.

The bent front end 121 a is positioned so that it is capable of abutting against the lower end of the actuator rod 1 3a extending from the indicator sleeve 1 3 of the indicator. The actuator rod 1 3a is provided with a return spring 1 25 whose one end is connected to the lower end of said actuator rod 13a. The other end of the return spring 125 is secured to the inner wall surface of the model cover 101.

In this embodiment, when the movable contact 107 is in its opened state, as shown in Fig. 8, no push-up force is exerted by the actuator plate 121, so that the actuator rod 1 3a remains depressed by the resilient force of the return spring 1 25. Therefore, in this state, the indication, e.g., green color, formed on the inner wall surface of the throughgoing hole of the mold cover 101 is viewed from the indicator window, i.e., the transparent cover 21, as shown in Fig. 2. Thereby, the fact that the switch 100 is in the opened state can be ascertained.

When the movable contact assembly is brought to its closed position so that movable contact 107 contacts the fixed contact 105, the movable contact lever 109 and detection lever 11 9 are turned counterclockwise around the axis of the cross bar 11 7, with the result that the actuator plate 121 is pushed up in the direction of arrow. In response thereto, the bent front end 121 a of the actuator plate 121 abuts against the lower end of the actuator rod 1 3a to push up the latter against the resilient force of the return spring 1 25. Therefore, in this condition, the indicator assumes the condition shown in Fig. 3, wherein the indication, e.g., red color, formed on the inner peripheral surface of the indicator sleeve 13 is viewed through the transparent cover 21. In this manner, in response to the turning movement of the movable contact assembly and cross bar between the opened and closed positions, the displacement is transmitted to the actuator rod 1 3a of the indicator sleeve 1 3, and the circuit condition of the switch can be clearly depicted by the indicator and viewed from the front of the enclosure (mold cover 101). Thereby, the fact that the switch 200 is in the closed state can be clearly ascertained.

As described above, according to the embodiment, since the indicative surface is reflected by the conical mirror surface so that it can be viewed from the front of the enclosure, the indicative area is large and hence the circuit condition of the electrical switch can be clearly distinguished and ascertained. Further, since it is not necessary to impart a rotary movement to the indicator member as in the prior art and instead a linear movement is sufficient, the space occupied by the indicator is small and even if the mechanical stroke is short, the change of condition of indication can be clearly detected. In other word, according to this embodiment, it is not necessary to so much increase the actuation stroke in order to clearly distinguish the change of condition of indication, and in this respect also the size can be reduced.

In addition, the indication (the second visible information) provided on the inner peripheral surface of the spot-faced hole 3 of the enclosure may be omitted. In this case, only one kind of indication by the indicator sleeve 13 would be possible.

Fig. 9 is a schematic view showing another example of an electrical switch embodying this invention; Fig. 10 is an exploded perspective view showing the principal portion thereof; and Figs.

11 and 1 2 are partly broken-away side views taken as indicated by the line B-B in Fig. 9 for explaining the operation thereof.

The electrical switch 200 in this embdoiment also has a mold cover 201 constituting an enclosure and an operating handle 203 operable from the front of the mold cover 201. The mold cover 201 has a mirror member 17 to be later described which has one end thereof exposed.

The surface of the mold cover 201 is formed with a spot-faced hole 3 whose bottom is centrally formed with a throughgoing hole 9 leading to the interior of the mold cover 201. The bottom of the spot-faced hole 3 serves as a mount 7. Placed on the mount 7 is a cylindrical indicator member i.e., indicator sleeve 13, and an actuator rod 1 3a extending from the bottom middle region of the indicator sleeve 13 is inserted in the throughgoing hole 9. The mirror member 17 is made of transparent material such as glass or acrylic resin and includes a columnar portion 18 and a flange 20 integrally formed on one end surface of said columnar portion 18. The other end of the columnar portion 18 is formed with a conical recess whose surface is formed with a mirror surface 19 as by vapor deposition of aluminum.The flange 20 is secured to a step 11 formed in the mold cover 201 around the peripheral edge of the spot-faced hole 3, whereby the mirror surface is fixedly held at a predetermined position in the throughgoing hole, i.e., spot-faced hole 3.

The inner surface of the mold cover 201 is formed with a step-like receiving portion 201a adjacent the spot-faced hole 3. A pair of threaded member 29 are embedded in the inner surface of the mold cover 201 with said mold cover 201 a and spot-faced hole 3 interposed therebetween.

Each threaded member 29 has an internal thread tapped therein. In the mold cover 201, a cover plate 27 together with a plate spring 25 is fixed to the threaded members 29 by screws 31. That is, a hole 25a formed in one end of the plate spring 25 is placed over one hole 27a, so that the plate spring 25 is fixed to the mold cover 201 by the screws 31. The plate spring 25 is bent to have a trapedoidal cross-section and is formed at the other end thereof with a fitting slot 25b. The fitting slot 25b is fitted to a circumferential groove 1 3b formed in the actuator rod 1 3a extending through the throughgoing hole 9 into the mold cover 201, and the other end of the plate spring 25 is connected to the actuator rod 13a, i.e., the indicator sleeve 13.The region of the cover plate corresponding to substantially the middle of the plate cover spring 25 is formed with a rectangularthroughgoing hole 27b. An actuator plate 221 (Fig. 11) to be later described will be inserted through the throughgoing hole 27b of said cover plate 27.

In addition, the inner diameter of the indicator sleeve 13 is greater than the outer diameter of the columnar portion 18 of the mirror member 17, as described above. The inner peripheral surface 1 5 of the indicator sleeve 1 3 is formed with an indicative surface 1 5 including first visible information such as a character, figure, design, or color or a combination thereof. In this embodiment, the indicative surface 1 5 is colored red.

On the other hand, the inner peripheral surface of the spot-faced hole 3 at the position associated with the mirror surface 1 9 is formed with an indicative surface 5 including second information such as a character, figure, sign or color or a combination thereof. In this embodiment, the indicative surface 5 is colored green.

Referring to Fig. 11, the mold base 202 cooperating with the mold cover 201 to constitute the enclosure has a fixed terminal conductor 205 fixed thereto. The bent conductor 205a of the fixed terminal conductor 205 is formed at substantially the middle thereof with a fixed contact 207, while a movable contact 209 associated with said fixed contact 207 is provided. The movable contact 209 is formed on the front end of a movable contact lever 211, which is integrally pivotally supported by a contact holder 213 by means of a shaft 215 and is turnable around the axis of the rotary shaft 217 of the contact holder 21 3. The contacted holder 213 together with a contact holder for the other pole is connected to a cross bar 219, thereby constituting a movable contact assembly.By operating the operating handle 203 projecting out of the mold cover 201, the movable contact assembly is displaced between the opened and closed positions through a switching mechanism (not shown).

The other end of the contact holder 213 has one end of the actuator plate 221 pivotally connected thereto. The substantially middle region of the actuator plate 221 is formed with a longitudinal guide hole 225, in which a guide pin 229 installed in a fixed frame 227 is slidably fitted, thereby converting the rotary movement of the contact holder 213 into a linear movement of the actuator plate 221. The other end of the actuator plate 221 projects through the throughgoing hole 27b of the cover plate 27 of the indicator to be associated with the plate spring 25.

As shown in Fig. 11, when the movable contact 209 is in the open circuit position, the front end 221 a of the actuator plate 221 does not abut against the plate spring 25 but is spaced apart from the latter. Therefore, the plate spring 25 retains its original shape by its resiliency and hence the actuator rod 1 3a of the indicator sleeve 13 remains pulled down. In this condition, the second visible information, e.g., green color, formed on the inner peripheral surface of the throughgoing hole 3 of the mold cover 201 is reflected by the mirror surface formed on the mirror member 1 7 and is indicated on the front surface of the mold cover. Thereby, it is ascertained that this switch 200 is in the open circuit condition.

Next, if the movable contact 209 and the fixed contact 207 are brought into the contacted state, i.e., the closed circuit position, as shown in Fig.

12, the actuator plate 221 is substantially linearly upwardly moved in operative association with the turning movement of the movable contact lever 211, i.e., contact holder 213, so that the front end 221 a of the actuator plate 221 pushes up the plate spring 25. Then, the actuator rod 13a, i.e., the indicator sleeve 13, connected to the front end of this plate spring 25 is pushed up, so that the indicative surface 1 5 formed on the inner peripheral surface of the indicator sleeve 13 is associated with the mirror surface 1 9. In this condition, the first visible information, e.g., red color, formed on the indicative surface 1 5 can be viewed from the front of the mold cover 201.

Thus, it can be ascertained that this switch is in the closed circuit state.

In addition, the formation of the mirror surface on the inclined surface of a circular cone is preferable in the dead angle is eliminated and hence the indication can be ascertained from any angle without causing misunderstanding.

However, it goes without saying that the mirror surface may be in the form of a circular cone or a pyramid.

According to this embodiment, since the visible information is reflected by the conical mirror surface so that it can be viewed from the front of the enclosure, there is no need to impart a rotary movement to the indicator member as in the prior art and hence the indicator occupies a small space. Further, since the mirror surface, the indicator member and the plate spring are integrally installed in the enclosure (the mold cover 201, in the embodiment) and the indicator is separable from the switching mechanism, the dismounting for inspection or other purpose becomes easier. Further, since the difference between the stroke of the indicator member and the stroke of the actuator plate can be accommodated by the resiliency of the plate spring, the tolerance for assembly can be increased and hence assembly is facilitated.

Fig. 1 3 is a schematic view showing an example of a circuit breaker embodying this invention, and Figs. 14 through 1 7 are diagrammatic views for explaining the arrangement and operation of said circuit breaker.

Figs. 15 through.1 7 are sectional views taken along the line C-C in Fig. 13.

The circuit breaker 300 includes a mold cover 301 constituting an enclosure, and an operating handle 31 6 is provided which extends out of the mold cover 301 so that it is operable from the outside. Disposed on the surface of the mold cover 301 is a mirror member 1 7 to be later described.

The construction of this circuit breaker will now be described with reference to Figs. 14 through 17. The circuit breaker includes a mold base which cooperates with the mold cover 301 to constitute the enclosure, said mold cover 301 and mold base 302 being made of electrical insulator. The mold base 302 has fixed thereto connection terminals 303 and 303' and fixed contact assembly 304, said fixed contact assembly 304 including a terminal conductor 305 shown one end is connected to the connection terminal 303. The other end of the terminal conductor 305 is formed with a fixed contact 306. A movable contact assembly 307 includes a movable contact lever 308, whose one end is formed with a movable contact 309 associated with the fixed contact 306.The movable contact lever 308 is turnably supported by a contact holder 311 by means of a contact shaft 310, the other end of said contact lever 308 being contact to an intermediate connector 313 by a flexible conductor 31 2. The end of the contact holder 311 is connected to a cross bar 327 of insulator and it is turnable around the axis 328 thereof.

One end of a main current conductor 314 is connected to the intermediate connector 313 and the other end is connected to the connection terminal 303' through a terminal conductor 315.

An intermediate portion of the main current conductor 314 is formed with a bent heater portion 314a.

As a mechanism for opening and closing the movable contact 309, there is provided an operating handle 31 6 of insulator projecting out of the enclosure, i.e., mold cover 301. The operating handle 316 has an opening and closing lever 31 7 of U-shaped cross-section attached thereto, said opening and closing lever 31 7 being turnably supported at its lower end by an opening and closing lever shaft 31 8. The turning lever shaft 318 is installed on a fixed frame 319.

Therefore, the opening and closing operation on the movable contact assembly can be effected by moving the operating handle 316 around the axis of the opening and closing lever shaft 31 8.

A trip lever 320 serving as a release member is turnably supported at one end thereof by a trip lever shaft 320b bridging the fixed frame 319, the other end 320a being adapted to releasabiy engaged with a main hook 321. A shaft 324 installed at the upper end of the middle portion of the trip lever 320 is connected to one end of a toggle link 322 included in a pair of toggle links 322 and 323, the other end of said toggle link 322 being connected to a toggle link shaft 325.

The other toggle link 323 is connected at one end thereof to the toggle link shaft 325 and at the other end to the contact holder 311 and movable contact lever 308 by the contact shaft 310. The toggle shaft 325 has a pair of operating springs 326 connected at one of their respective ends thereto, the other ends of said operating springs 326 being connected to the spring arrester 31 7a of the opening and closing lever 17. That is, the operating springs 326 are connected between the toggle link shaft 325 and the opening and closing lever 317, thus forming a toggle type opening and closing mechanism. By means of this operating mechanism, the contact holder 311 connected to the cross bar 327, and the movable contact lever 308 are turned between the opened and closed positions around the axis 328 of the cross bar 327.

In addition, the movable contact lever 308 is normally biased in the circuit closing direction with respect to the contact holder 311 by a contact spring 329.

A displaceable member 330 is provided which is used to actuate the indicator sleeve 1 3 (Fig. 1 8) of the indicator at the time of automatic trip. The displaceable member 330 is integrally mounted on a portion of the trip lever 320 and extends to a pole adjacent to a pole chamber provided with the operating mechanism.

The main hook 321 is turnabiy supported on a hook pin 331 supported in the fixed frame 319, said main hook 321 having an erected plate portion and is arranged so that the lower end of an engaging element 321 a mounted on the upper end of the plate portion engages one end of the trip lever 320. In addition, the main hook 321 is normally urged to be turned clockwise. A trip shaft 332 with which the respective plate are associated is turnably supported at the center thereof by the fixed frame 319. Further, the trip shaft 332 has a projection which is inserted in the window opening 321 b of the main hook 321 and which presses and engages the lateral surface of the engaging element 321 a.Further, in the trip shaft 332, a trip piece 334 is installed for each pole, said trip piece 334 being provided with the free end of a bimetal 335 and the upper leg of the movable iron piece of an electromagnetic device for instantaneous release. The bimetal 335 is integrally connected at the lower end thereof to said heater 31 4a which serves as a thermal release element responsive to overcurrent which occurs as in abnormal condition. The movable iron piece 336 (central pole) of the electromagnetic device is turnably supported by the shaft 337, and the lower leg of the movable iron piece 336 is associated with a fixed core 338 through which the main current conductor 314 extends. The fixed core 338 is mounted on a fixed core support plate 339 supported on the mold base 302.The movable iron piece 336 is biased in the clockwise direction by a movable iron piece return spring 341 installed between the upper portion of the fixed core support plate 339 and a catch 340 provided on the upper pole f the movable core 336.

In order to open the circuit into the usual manner from the closed circuit state shown in Fig.

15, the operating handle 316 is moved to the offside, i.e., to the right as viewed in Fig. 15. As a result, the pair of toggle links 322 and 323 are deeply bent to pull up the contact shaft 310 which connects the contact holder 311 and movable contact lever 308. In response thereto, the movable contact 309 is moved around the rotary axis 328 of the contact holder 311 to separate from the fixed contact 306, whereby the usual off-state is established.

To close the circuit, the operating handle 316 is moved to the on-side, i.e., to the left as viewed in Fig. 16, whereupon the toggle links 322 and 323 are extended to thereby turn the contact holder 311 and cross bar 327 in the throwing direction, so that the contacts 306 and 309 are closed.

If an overcurrentflows in the closed circuit state, the bimetal 335 warps owing to the heat produced by the current, with its free end pushing the trip piece 334 to turn the trip shaft 332 in the counterclockwise direction. Further, in the case of a short-circuit current, the fixed core 338 of the electromagnet device for instantaneous release is energized to attract the lower end of the movable iron piece 336. Then, the movable iron piece 336 is turned counterclockwise around the axis of the shaft 337, with its upper end pressing the trip piece 334, causing the trip shaft 332 to turn counterclockwise. When the trip shaft 332 is turned counterclockwise in this manner, the engagement between the engaging element 321a of the main hook 321 and the projection 333 is cancelled and the main hook 321 is turned clockwise.When the main hook 321 is turned clockwise, the projection 333 on the trip shaft 332 slips deep into the window opening 321 b of the main hook 321 and concurrently therewith the engagement between the front end 320a of the trip lever 320 and the engaging element 321 a of the main hook 321 is cancelled, so that the trip lever 320 is turned counter-clockwise. Therefore, the toggle links 322 and 323 are folded deep to pull up the contact holder 311, so that the movable contact 309 is separated from the fixed contact 306, thus establishing the trip state in which the circuit is cut off, as shown in Fig. 1 7.

Fig. 1 8 is an exploded perspective view showing an embodiment wherein this invention is applied to a circuit breaker such as the one described above.

A mold cover 301 is formed with a spot-faced hole 3 whose bottom is centrally formed with a throughgoing hole 9 leading to the interior of the mold cover 301. The bottom of the spot-faced hole 3, i.e., mount 7 has an indicator sleeve 13 placed thereon. That is, an actuator rod 1 3a downwardly extending from the middle of the bottom of the indicator sleeve 13 is inserted in the throughgoing hole 9, with the indicator sleeve 13 axially linearly displaceably received in the spot-faced hole 3. The portoin of the mold cover 301 around the peripheral edge of the spot-faced hole 3 is formed with a step 11, in which a flange 20 on a mirror member 17 is fitted. The mirror member 1 7 is made of transparent material such as glass or acrylic resin and includes a columnar portion 18 and flange 20 formed on one end of the columnar portion 18.The other end of the columnar portion 18 is formed with a conical recess, whose inner surface is formed with a mirror surface 1 9 as by vapor deposition of aluminum.

In the inner wall surface of the mold cover 301, the portion adjacent to the spot-faced hole 3 is formed with a receiving portion 301a having a threaded element 29 embedded in one end of said receiving portion 301 a. The threaded element 29 has an internal thread tapped therein.

One end of a plate spring 25 is fixed to the threaded element 29 through a hole 25a. The plate spring 25 is bent substantially into a trapezoid and has a fitting slot 25b formed in the free end thereof. The fitting slot 25b is fitted to a circumferential groove 1 3b formed in the actuator rod 1 3a extending through the throughgoing hole 9. In this manner, the actuator rod 13a, i.e., indicator sleeve 13 is connected to the plate spring 25.

The inner peripheral surface 1 5 of the indicator sleeve 1 3 is formed with an indicative surface 1 5 including first visible information such as a character, figure, sign or color or a combination thereof. In this embodiment, the indicative surface 1 5 is colored white. On the other hand, the inner peripheral surface of the spot-faced hole 3 at the position associated with the fixed mirror surface 1 9 is formed with an indicative surface 5, including second visible information such as a character, figure, sign or color or a combination thereof. In this embodiment, the indicative surface 5 is colored black.

A displaceable member 330 is provided so that it is capable of abutting against the bent lower end of the plate spring 25 and is loosely inserted in an elongated throughgoing hole 349a in an insulation barrier 349. The return spring or plate spring 25 is actuated to push up the indicator sleeve 1 3 during automatic trip in association with the extension of the displaceable member 330 for the trip lever 320 of a release member provided at the middle pole.The displaceable member extends through a throughgoing hole 349a in an insulation barrier 349 mounted in the cut groove 302b (Fig. 14) of the inter-pole partition wall 302a at the mold base 302 in such a manner as to close an opening 348 in the partition wall for the adjacent pole in the mold cover 301, and the shape of the throughgoing hole 349a is such as not to prevent the operation at the time of automatic trip of the displaceable member 330.

Figs. 1 9 and 20 are sectional diagrammatic views taken along the line D-D in Fig. 13, for explaining the operation of the aforesaid embodiment. In the case of the on-state and normal off-state shown in Figs. 1 5 and 16, the indicator is in the state shown in Fig. 1 9. That is, the return spring 25 and displaceable member 330 are associated with each other in spaced relation. Therefore, the indicator sleeve 13, i.e., the actuator rod 1 3a remains pulled down to the lower end position by said spring 25.Thus, in this condition, the indication, e.g., black color, on the second indicative surface 5 (Fig. 18) formed in the spot-faced hole 3 becomes visible from the mirror member 1 7. This situation makes it possible to ascertain that the circuit breaker is not in the automatic trip state.

Further, in the automatic trip state shown in Fig.17, the displaceable member 330 is turned together with the trip lever 320. Therefore, as shown in Fig. 20, the displaceable member 330 pushes up the plate spring 25 to raise the actuator rod 1 3a and hence the indicator sleeve 1 3 to the position where it is associated with the mirror surface 1 9. Therefore, in this state, the first visible information, e.g., white color, included in the first indicative surface 1 5 formed on the inner peripheral surface of the indicator sleeve 13 becomes visible from the front of the mold cover 301.This situation makes it possible to ascertain that the circuit breaker is in the automatic trip state owing to overcurrent or short-circuit accident.

According to this embodiment, since visible information is reflected by the conical mirror surface so that it is visible from the front side of the enclosure, it is not necessary to impart a rotary movement to indicator member as in the prior art and hence the indicator occupies a smaller space. Further, since the mirror member, indicator member and plate spring are integrally installed in the enclosure (the mold cover 201, in the embodiment) so that the indicator is separable from the opening and closing mechanism, mounting and dismounting for inspection or other purpose becomes easy.

Further, since the difference between the stroke of the indicator member and the stroke of the actuator plate can be accommodated by the resiliency of the plate spring, the tolerance for assembly can be increased and hence assembly is facilitated.

In the above embodiment a case has been described in which only two types of indication, i.e., the first indication by the indicator sleeve 13 and the second indication by the throughgoing hole or spot-faced hole 3 are possible. However, by marking the indicative surface 5 of the inner wall surface of the spot-faced hole 3 with a suitable scale, it is possible to provide more types of indication. Therefore, the indicator of this invention may be used to provide analog indications.

As has been described so far, according to this invention, an indicator for electrical switches which is small-sized and reliable can be obtained.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.

Claims

1. An indicator for electrical switches, comprising: an enclosure (1, (1,101,201,301) in which a displaceable member (121,221,330) adapted to be displaced depending on the circuit condition of an electrical switch, an opening (3, 9) formed on the surface of said enclosure (1,101,201,301) in a direction perpendicular to said surface, said surface having said opening (3, 9) formed as an indicator window, a mirror surface (19) in the form of a conical or pyramidal surface fixed at a predetermined position in said opening (3, 9) so that its apex points to said indicator window, an indicator member (13) adapted to surround said mirror surface (19) and linearly displaceable within said opening (3, 9), a first indicative surface (15) including first visual information formed on the inner peripheral surface of said indicator member (13), and means (1 3a, 25) for transmitting the displacement of said displaceable member (121, 211, 330) to said indicator member (13), the arrangement being such that when said first indicative surface (15) is associated with said mirror surface (19) depending upon the displacement of said displaceable member (121,211,330), said first visual information becomes visible through said indicator window.

2. An indicator for electrical switches as set forth in claim 1, including a second indicative surface (5) including second visual information and formed on the inner peripheral surface of said opening (3, 9), at the position associated with said mirror surface (19, the arrangement being such that when said first indicator surface (15) of said indicator member (13) is not in the position associated with said mirror surface (19), said second visual information becomes visible through said indicator window.

3. An indicator for electrical switches as set forth in claim 1,wherein said mirror surface (19) is formed on the outer surface of a cone (17).

4. An indicator for electrical switches as set forth in claim 1, including a columnar transparent member (18) having a conical or pyramidal recess at one end thereof, said mirror surface (19) being formed on the surface of said recess.

5. An indicator for electrical switches as set forth in claim 4, wherein said columnar transparent member is fixed to said enclosure (1, 101, 201, 301) so that its other end points to said indicator window, whereby said mirror surface (19) is fixed in position within the opening (3,9).

6. An indicator for electrical switches as set forth in claim 5, including a flange (20) integrally formed on the other end of said columnar transparent member (18), said flange (20) being fixed to said enclosure (1, 101,201, 301), whereby said mirror surface (19) is fixed in position within said opening (3, 9).

7. An indicator for an electrical switch comprising an inclined reflective surface and a member displaceable in dependence upon the condition of the switch into and out of a position where said reflective surface projects a reflection of an indicia surface of said member.

8. An indicator, for an electrical switch, substantially as herein described with reference to any of the accompanying drawings.

9. An electrical switch including an indicator as claimed in any of the preceding claims.

10. An electrical switch substantially as herein described with reference to any of Figs. 7 to 20 of the accompanying drawings.