AU705384B2

AU705384B2 - Circuit-pole circuit breaker

Info

Publication number: AU705384B2
Application number: AU61817/96A
Authority: AU
Inventors: Adolf Tetik
Original assignee: Felten and Guilleaume Austria AG
Current assignee: Felten and Guilleaume Austria AG
Priority date: 1995-07-28
Filing date: 1996-07-10
Publication date: 1999-05-20
Anticipated expiration: 2016-07-10
Also published as: ATE176360T1; AT408929B; EP0842525A1; AU6181796A; ATA129395A; CZ26798A3; HU220831B1; CZ287500B6; GR980300053T1; ES2118676T1; DE59601238D1; HUP9802641A3; WO1997005638A1; EP0842525B1; HUP9802641A2

Abstract

A single-poled circuit breaker has a housing (1, 2) which there are a fixed (14) and a movable contact (15) connected to terminals (10, 11). The movable contact (14) is fitted on a switching bridge (4) arranged to pivot in the housing (1, 2) and connected to the switch button (3) via a lever (6). The switching bridge (4) is spring-loaded (7) in the closed position. When the switch button (3) is actuated, one end (17) of the lever (6) slides along a control slide (19) on the button (3) having two end stops (20, 21) and a supporting surface (23) between them, on which the lever (6) is temporarily supported during switch-on. The control slide (19) with the supporting surface (23) makes it possible to close the contacts (14, 15) rapidly but not so quickly that the movable contact (15) "vibrates" on the fixed contact (15), thus preventing the contacts (14, 15) from fusing together.

Description

CIRCUIT-POLE CIRCUIT BREAKER The present invention relates to a single-pole circuit breaker having a housing accommodating a fixed contact and a movable contact which are connected to terminals, whereby the movable contact is mounted on a switching bridge arranged to pivot in the housing a connected to the switch button by means of a lever, and whereby one end of the lever, when the switch button is actuated, slides along a control slide on the switch button having two end stops.

The invention additionally relates to a single-pole circuit breaker having a housing accommodating a fixed contact and movable contact which are connected to terminals, whereby the movable contact is mounted on a switching bridge arranged to pivot in the housing and connected to the switch button by means of a lever, and whereby one end of the lever, when the switch button is actuated, slides along a control slide on the switching bridge having two end stops.

In this type of switch the problem arises, especially with higher currents to be switched, for example 80A or higher, where shortly before the terminals are closed an arc begins to burn, which brings material on the contacts to melting point, causing the contacts to weld together following closing and cooling.

Switches, in which a lever between a switch button and a switching bridge slides along the switching bridge in a control slide on the switch button or on the switching bridge, are disclosed in GB 1 552 180 A and GB 2 157 499 A.

The object of the present invention is to overcome or at least substantially ameliorate at least one or some of the problems in the prior art, and it is not necessary that the invention in its broadest aspect should overcome all the 25 problems in the prior art.

According to the present invention, there is provided a single-pole circuit breaker having a housing accommodating a fixed contact and a movable contact which are connected to terminals and a switch button arranged to pivot in the housing, in which the movable contact is mounted on a switching bridge 30 arranged to pivot in the housing between an ON position in which the movable 5* contact cooperates with the fixed contact and an OFF-position in which the contacts are at a distance from each other, and in which the switching bridge is O' 4 2 connected to the switch button by means of a lever, whereby one end of the lever, when the switch button is actuated, slides along a control slide on the switch button having two end stops, characterised in that the switching bridge is spring-loaded into the ON-position through the force of a spring, and in that the end of the lever assigned to the control slide jumps through the force of the spring from one position on the control slide into another position, after passing a dead centre when switching on the circuit breaker.

The control slide may be formed by a recess arranged on the switch button.

According to another aspect of the invention, there is provided a singlepole circuit breaker having a housing accommodating a fixed contact and a movable contact which are connected to terminals and a switch button arranged to pivot in the housing, in which the movable contact is mounted on a switching bridge arranged to pivot in the housing between an ON-position in which the movable contact cooperates with the fixed contact and an OFF-position in which the contacts are at a distance from each other, and in which the switching bridge is connected to the switch button by means of a lever, whereby one end of the lever, when the switch button is actuated, slides along a control slide on the •switching bridge having two end stops characterised in that the switching bridge 20 is spring-loaded into the ON-position through the force of a spring, and in that :the end of the lever assigned to the control slide jumps through the force of the spring from one position on the control slide into another position, after passing a dead centre when switching on the circuit breaker.

2The control slide may be formed by a recess arranged on the switching 25 bridge.

The switch button may be swivel-mounted in the housing.

The switching bridge may be swivel-mounted in the housing.

Arranged between the end stops (20, 21) may be a bearing surface, on which the lever is supported temporarily during the switching-on movement.

o 30 The bearing surface may be arranged on a projection on the control slide.

The spring may be a compression spring which is supported on one side of the housing and on the other side on the switching bridge.

Arranged on the switch button may be a stop which presses the lever into the ON-position during the switching-on movement.

In order that the invention might be more fully understood, embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows an embodiment of a single-pole circuit breaker in the switched-on position, with the upper shell removed, Figure 2 shows a front view of the housing of the circuit breaker with the upper shell replaced, Figure 3 shows the circuit breaker in the switched-off position, with the upper shell removed, Figure 4 shows the switch mechanism of th circuit breaker on an enlarged scale in an intermediate switching position and, Figure 5 shows the switch button of the single-pole circuit breaker.

Referring to the drawings, the circuit breaker according to the present embodiment essentially comprises a housing with a lower shell 1 and upper shell 2, which accommodates terminals 10, 11 in a manner known in and of itself. Terminal 10 is connected by means of a round rope 8 to a switching bridge 4 which is mounted by one end by a bolt 13 in housing 1, 2. Disposed at 20 the other end of switching bridge 4 is a movable contact 14 which cooperates with a fixed contact 15 to establish an electrical connection between terminals and 11 by means of a conducting strip 12, to which contact 15 and second terminal 11 are attached, this when the circuit breaker is switched on.

Mounted approximately in the central region of switching bridge 4 is an angled end 16 of an essentially U-shaped lever 6 which may be, for example, a wire bail. The other angled end 17 of lever 6 is taken up in a recess or groove 18 in a switch button 3 which is swivel-mounted in housing 1, 2.

Recess 18 is limited on the side averted from switching bridge 4 by a control slide, as in Figure 5, on which lever 6 is supported spring-loaded by its 30 angled end 17 through the force of a spring 7; this spring 7 is a compression spring which is supported on one side on switching bridge 4, and on the other side on housing 1.

Control slide 19 or recess 18 is limited by end stops 20, 21. Mounted in the central region of control slide 19 offset somewhat to end stop 20 is a protrusion 22 which forms a bearing surface 23 for lever 6.

If the circuit breaker according to the present embodiment is switched on from the OFF-position illustrated in Figure 3, in that switch button 3 is actuated in an anti-clockwise direction, lever 6 slides, after the dead centre has been overcome, in which the rotational axis of switch button 3 lies approximately in the extension of lever 6, with its end 17 away from end stop 21 into the position illustrated in Figure 4, in which end 17 rests on bearing surface 23, whereby the "uncontrolled" closing movement of switching bridge 4 is checked on fixed contact 15. In this position both contacts 14 and 15 are at a distance of only approximately 1 mm from one another.

If switch button 3 is now rotated further in an anti-clockwise direction, end 17 of lever 6 slides away from bearing surface 23 on projection 22 and contacts 14 and 15 are closed abruptly. Since the movement of the switching bridge was in the meantime momentarily impaired by the running up of lever 6 on bearing surface 23, the velocity or the kinetic energy of switching bridge 4 is no longer so great that movable contact 14 lifts or recoils unwantedly from fixed contact effectively reducing the risk of contacts 14, 15 being welded. On the other hand 20 however, after lever 6 has slid away from bearing surface 23, there is the possibility of an unhindered and relatively rapid closing of contacts 14, which is also necessary for closing of contacts 14, 15 without their being welded together.

In order to support end 17 of lever 6 sliding away from bearing surface 23 l25 and to enable this action to be controlled, a stop 25 is mounted on switch button o* 3, which rests on lever 6 in the position illustrated in Figure 4 and which presses the latter down with further anti-clockwise movement of switch button 3 from bearing surface 23.

To switch off the switch, switch button 3 is first rotated sufficiently in a 30 clockwise direction for end 17 of lever 6 to rest on end stop 20. With further turning of switch button 3 movable contact 14 is then lifted from fixed contact After lever 6 has again overcome dead centre it jumps to the left over projection 22 on the control slide with its end 17 to end stop 21 and presses switch button 3 further in a clockwise direction until the latter comes to rest on a bearing surface 26 on housing 1, 2.

It is understood that modifications of the embodiment illustrated in the diagrams are possible within the scope of the invention. By way of example, the switch button and the switching bridge can be mounted dispaceably in the housing, rather than swivel-mounted. In addition, the control slide can be mounted on switching bridge 4, instead of on switch button 3. It is also possible that in the case of not the preferred embodiment of the invention, no bearing surface is provided on the control slide and the movement of the lever is supported on the control slide only by stop In summary, an embodiment of the invention can be represented as follows: A single-pole circuit breaker exhibits a housing 1, 2 accommodating a fixed contact 14 and a movable contact 15 which are connected to terminals 11. Movable contact 15 is mounted on a switching bridge 4 arranged to pivot in housing 1, 2, which is connected to switch button 3 by means of a lever 6.

Switching bridge 4 is spring-loaded into the closing position by means of the *s force of a spring 7. When switch button 3 is actuated, lever 6 slides with an end 20 17 along a control slide 19 on switch button 3 which has two end stops 20, 21 and between these two end stops 20, 21 a bearing surface 23, on which lever 6 is supported temporarily during the switching-on movement.

By way of control slide 19 with bearing surface 23 it is possible that contacts 14, 15 close quickly, but not so quickly that movable contact 14 25 "vibrates" on fixed contact 15, such that contact 14, 15 are not welded together.

In the embodiment, the switch is loaded in the closing position through the force of a spring, and by the end of the lever assigned to the control slide springing from one position on the control slide to another position through the force of the spring, after the dead centre has been exceeded.

30 The embodiment takes advantage of the fact that the fusing of the contacts and consequent welding thereof is all the less, the shorter the duration of the switching procedure, that is, the faster the contacts close. By means of the 6 control slide, which, in the embodiment, is mounted either on the switching bridge or preferably on the switch button, the lever can move freely along the control slide on a predetermined switch path, without being bound to the movement of the switch button, when the unit is switched on, whereby the contacts can close rapidly and unhindered.

A concomitant problem is that the movable contact on the switching bridge appears at the fixed contact so quickly that it springs back therefrom and rests on the fixed contact only after several instances of impacting and recoiling.

Because an arc is also struck at this time, which can lead to undesired welding of the contacts, a further feature in the embodiment provides for the control slide to exhibit two end stops and for a bearing surface to be disposed between these end stops, on which the lever is supported temporarily during the switching-on movement.

When the switch is closed the lever rests on this bearing surface, until the contacts are almost closed, after which it slides away from the latter further freely along the control slide, until the contacts are closed. Due to the very short distance between both contacts at the moment of the lever slides from the bearing surface, the impact velocity of the movable contact on the fixed contact is so minimal that the abovementioned lifting of the movable contact from the 20 fixed contact can be prevented almost entirely, yet it is great enough for no welding of the contacts to result therefrom.

In order to best control the motion of the lever on the control slide, especially the sliding of the lever away from the bearing surface, a further feature of the embodiment provides for a stop to be arranged on the switch 25 button, which presses the lever into the ON-position during the switching-on S movement.

The lever is moved along the control slide by means of the stop on the switch button, especially as it is forced away from the bearing surface, whenever the distance between the two contacts has attained a predetermined value, such 0O 30 that the time period, during which the lever slides away from the bearing

S

of7 surface, that is, at which distance between the two contacts this occurs, is not influenced by finishing accuracies or instances of abrasion on the bearing surface.

The embodiments have been defined by way of example only, and modifications are possible within the spirit and scope of the invention as defined by the appended claims.

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Claims

1. A single-pole circuit breaker having a housing 2) accommodating a fixed contact (14) and a movable contact (15) which are connected to terminals 11) and a switch button arranged to pivot in the housing in which the movable contact (15) is mounted on a switching bridge arranged to pivot in the housing 2) between an ON position in which the movable contact cooperates with the fixed contact (14) and an OFF-position in which the contacts (14 and 15) are at a distance from each other, and in which the switching bridge is connected to the switch button by means of a lever whereby one end (17) of the lever when the switch button is actuated, slides along a control slide (19) on the switch button having two end stops (20, 21), characterised in that the switching bridge is spring-loaded into the ON- position through the force of a spring and in that the end (17) of the lever (6) assigned to the control slide (19) jumps through the force of the spring from one position on the control slide (19) into another position, after passing a dead V, centre when switching on the circuit breaker.

2. A circuit breaker as claimed in Claim 1, characterised in that the control slide (19) is formed by a recess arranged on the switch button

3. A single-pole circuit breaker having a housing 2) accommodating a fixed contact (14) and a movable contact (15) which are connected to terminals 11) and a switch button arranged to pivot in the housing in which the movable contact (15) is mounted on a switching bridge arranged to pivot S:o in the housing 2) between an ON-position in which the movable contact cooperates with the fixed contact (14) and an OFF-position in which the contacts (14 and 15) are at a distance from each other, and in which the switching bridge is connected to the switch button by means of a lever whereby one end (17) of the lever when the switch button is actuated, slides along a control slide (19) on the switching bridge having two end stops (20, 21) characterised in that the switching bridge is spring-loaded into the ON- position through the force of a spring and in that the end (17) of the lever (6) assigned to the control slide (19) jumps through the force of the spring from one position on the control slide (19) into another position, after passing a dead centre when switching on the circuit breaker.

4. A circuit breaker as claimed in claim 3, characterised in that the control slide is formed by a recess arranged on the switching bridge A circuit breaker as claimed in any one of claims 1 to 4, characterised in that the switch button is swivel-mounted in the housing 2).

6. A circuit breaker as claimed in any one of claims 1 to 5, characterised in that the switching bridge is swivel-mounted in the housing 2). S7. A circuit breaker as claimed in any one of claims 1 to 6, characterised in that arranged between the end stops (20, 21) is a bearing surface on which the lever is supported temporarily during the switching-on movement.

8. A circuit breaker as claimed in claim 7, characterised in that the bearing surface (23) is arranged on a projection (22) on the control slide (19).

9. A circuit breaker as claimed in any one of claims 1 to 8, characterised in that spring is a compression spring which is supported on one side of the 00 :4 housing 2) and on the other side on the switching bridge *0 S. 10. A circuit breaker as claimed in any one of Claims 1 to 9, characterised in that arranged on the switch button is a stop (25) which presses the lever (6) into the ON-position during the switching-on movement. A, L

11. A single-pole circuit breaker substantially as hereinbefore described and illustrated with reference to the accompanying drawings. DATED this 1st day of March, 1999. FELTEN GUILLEAUME AUSTRIA AG WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA SKP:RJS:JL VAX dcc 025 AU61 81 796.WPC 0* 0 .0 0 of