EP0147629A1 - Protective circuit breaker - Google Patents

Abstract

1. Manually operable protective switch having the following features : the protective switch (1) has a magnetic and/or bimetallic release device (7, 8) acting on a latch (6) which can be locked and unlocked with a handle (4), the latch (6) essentially consists of a pivot lever (17) rotatably mounted in a switch housing (2) and an unlatching lever (18) interacting with this pivot lever (17), the pivot lever (17) transmits the pivoting movement of the handle (4) to a contact arm (13) which is elastically coupled to the pivot lever (17), is pivotable in the switch housing (2) and interacts with a fixed contact (14), the unlatching lever (18) is acted upon by the magnetic and/or bimetallic release device (7, 8) and is provided with a latching point for a transmission stirrup (26) acting in the manner of a toggle joint between the handle (4) and the latch (6), characterized by the following features : the unlatching lever (18) is made as a lever lying parallel next to the pivot lever (17), is mounted on a separate rotary axis (19) arranged on the pivot lever (17) at a distance from its axis (16) and forms, together with the pivot lever (17), a doublelink chain, the unlatching lever (18), in its centre area (web 21), is supported on an abutment projection (22) which is fixed to the housing and is arranged at a distance from the axis (16) of the pivot lever (17), the transmission stirrup (26), with its end (25) on the latch side, is guided in restrained manner in the direction of action in a longitudinal slot (29) of the pivot lever (17) and at the same time acts directly on the latching point made as an upwardly protruding detent (24) of the unlatching lever (18), the detent (24), during the switch-on pivoting movement of the pivot lever (17), projects with decreasing degree of overlap into the path of motion of the transmission stirrup (26), which path of motion is determined by the longitudinal slot (29), and releases this transmission stirrup (26) during the pivoting release movement of the unlatching lever (18).

Description

Circuit breaker

The invention relates to a manually operable circuit breaker with the features of the preamble of claim 1. Such a switch is known from DE-PS 25 04 954 and has a lock which can be locked and unlocked by a handle designed as a rotary knob and on which a magnet and / or bimetallic release device acts. The switching lock in turn essentially consists of two levers, namely a pivot lever and a release lever cooperating with it, both of which are mounted on a common axis of rotation fixed to the housing and can be pivoted about this, the pivot lever for transmitting the pivoting movement of the handle to an elastically coupled to it, is provided in the switch housing pivotable and interacting with a fixed contact movement contact arm. The unlatching lever is actuated by the release devices and has at one end a latching point which serves to guide or release a transmission slide which acts as a knee joint and which transmits the force between the handle and the switching mechanism.

In the switch of the generic type, a hook-like projection on the unlatching lever engages over the transmission slide, which is designed as a wire bracket, and fixes it to a sloping surface of the pivoting lever, which is used for power transmission. During the manual switch-on and switch-off process, the pivoting lever and the unlatching lever move coaxially, so that the latching of the wire bracket end over the hook-like projection remains unchanged. If the release lever is rotated about the axis common to the two levers by means of a release device, the end of the wire bracket on the switch lock side is released so that it slides over the sliding inclined surface attached to the swivel lever, thereby rendering the support ineffective and the switch lock jumping into the off position. This sequence of movements has the disadvantage that the switch lock cannot suddenly jump to the switch-off position from the beginning after being unlatched. Rather, the switch-off pivoting movement of the switch lock is initially hindered by the necessary sliding of the end of the wire bracket facing the switch lock on the sloping surface. This necessary sliding is additionally hindered by the fact that the end of the wire bracket is pulled by a tension spring in the direction opposite to the direction of movement. This creates an undesirable time delay between the time of unlatching and the lifting of the contact arm. This is particularly disadvantageous in the case of short-circuit shutdowns. The wire bracket is biased by this tension spring in such a way that it is caught again in the off position by the hook-like projection of the unlatching lever.

Two opposite demands are made on this latching point: Firstly, the latching of the wire bracket at the start of the switch-on Movement be so sure that there is no ineffective "ratcheting" of the wire bracket when switching on, on the other hand the latching in the switch-on position of the key switch must be so critical that it is triggered by relatively small forces.

In the described embodiment, in which the unlatching lever and pivoting lever pivot about a common axis of rotation, the switching lock is therefore extremely sensitive to the smallest manufacturing tolerances, which unintentionally shift the compromise found between necessary, secure locking and easy triggering in one direction or the other.

In addition, the indirect drive of the movable contact arm via a helical compression spring, which acts as a toggle lever and is guided with an internal wire bracket, is complicated and prone to failure.

The invention has for its object to provide a circuit breaker such that the latch between the transmission element interacting with the handle and the switch lock securely latches at the start of a switch-on pivoting movement without adversely affecting the speed of the unlatching, all parts being simple to manufacture and install should be. This object is achieved by the characterizing features of claim 1.

It is regarded as the essence of the invention that a relative movement is carried out between the unlatching lever and the pivoting lever during the switching-on process, which is causally due to a non-coaxial mounting of the two levers. In contrast to the coaxial rotation of the two levers according to the state of the Technically, the unlatching lever carries out a rotary and sliding movement in the housing, which means that the latching element, which is designed as a locking lug, protrudes far beyond the path of movement of the transmission bracket end to be latched at the beginning of the pivoting movement, but withdraws more and more from the path of movement during the pivoting movement , so that the mutual overlap causing the latching is reduced to a necessary minimum at the end of the switch-on pivoting movement, ie in the switch-on position. A further retraction movement of the locking lug, which ultimately causes the switch to be triggered, is exclusively caused by the release elements (magnetic release, bimetallic release), which acts on the free end of the latching lever, which is designed as a single-arm lever, and rotates it further about its bearing axis arranged on the pivot lever. The critical area of coverage of the elements to be mutually latched is thus only established immediately before or when the switch-on position is reached.

During the possible motion sequences when switching on, off and off, the end of the transmission bracket to be latched is always securely guided in a longitudinal groove of the pivoting lever, so that additional transmission elements acting on the transmission bracket, e.g. Feathers and the like can be dispensed with entirely, which lead to an additional mechanical load on the latching area. The sequence of movements during the switch-off pivoting movement has the advantage over the prior art that the pivoting movement of the switch lock can jump to the switch-off position unhindered from the time of unlatching, which leads to a conceivably short tripping time of the circuit breaker and is particularly advantageous in the case of short-circuit disconnections.

The switching behavior of the circuit breaker is further improved in that, according to claim 2, the contact arm is mounted exclusively on the pivot lever. Additional drive-transmitting means can be completely dispensed with, the contact arm is guided in synchronism with the initial switch-on swivel movement of the swivel lever to the mating contact fixed to the housing and is already there under high contact pressure during the further transfer of the handle to the switch-on position.

Advantageously, the contact arm has an L-shaped angle bend at its fastening end, the end of which is articulated to the pivot lever by positive locking and the inside of the angle is acted upon by a compression spring in the direction of the pivot lever. At the moment the two contacts are closed, the angular deflection is lifted out of its form-fitting bed somewhat against the force of the compression spring and acts as a spring-loaded joint between the contact arm and the pivot lever.

Self-cleaning of the contact surfaces is achieved by a sliding process that takes place between the fixed contact and the contact arm during the last swivel-in phase. Causally, this is due to the fact that the contact arm not only rotates, but also rotates and rotates in the housing when it is lifted out of its form-fitting bed in the swivel lever.

The sliding process on the contact surface between the fixed contact and the contact arm is also advantageous when switching off. A possibly welded contact point is not only torn open in the direction of movement of the contact arm during this movement sequence, but is also additionally broken open by the shear force acting transversely to the direction of movement.

The sliding inclined surface according to claim 7 ensures that the handle is not unnecessarily inhibited during its return movement into the switch-off position. Claim 8 teaches a particularly advantageous "critical" end position of the locking lug in relation to the longitudinal groove in the pivot lever which defines the path of movement of the transmission bracket.

Due to the web protruding laterally in the central area of the unlatching lever, the wall thickness (and thus the mass) of the unlatching lever can be further reduced without unnecessarily weakening the central area, which ensures secure contact with the projecting head. By claim 10, the projecting web fulfills a double function, since it also serves as a counter bearing for a torsion spring that presses the unlatching lever against the housing-fixed contact projection. Claims 11 and 12 teach a particularly advantageous arrangement of the parts interacting with the switch lock in relation to other switch parts, with claim 14 a quick return of the handle to the switch-off / release position to display the respective switching state is achieved.

• Fig. 1 eine Seitenansicht der Funktionsteile eines Schalters in ausgeschalteter Stellung (teilweise im Schnitt),
• Fig. 2 eine Ansicht gemäß Fig. 1 in mittlerer Bewegungsstellung,
• Fig. 3 eine Ansicht gemäß Fig. 1 in Einschaltstellung,
• Fig. 4 eine Ansicht gemäß Fig. 1 in ausgelöster Stellung, wobei die Handhabe in Einschaltstellung festgehalten wird.

The invention is explained in more detail using an exemplary embodiment in the drawing. Show it:

• 1 is a side view of the functional parts of a switch in the off position (partially in section),
• 2 is a view of FIG. 1 in the middle movement position,
• 3 is a view of FIG. 1 in the on position,
• Fig. 4 is a view of FIG. 1 in the triggered position, with the handle being held in the on position.

Structure of the circuit breaker:

The circuit breaker 1 consists essentially of a switch housing 2, from the upper side 3 of which a handle 4, designed as a rotary lever, projects for manual actuation of the circuit breaker. In its interior 5, the circuit breaker 1 has a switch lock 6, which is arranged directly under the top 3 of the switch housing 2. Furthermore, a magnetic release device 7 and a bimetal release device 8 are provided. On the outside of the housing there are also connection elements in the form of screw terminals 9, 10, the screw terminal 9 being electrically connected to the bimetallic release device 8 and the screw terminal 10 being connected to the magnetic release device 7. The swivel end 12 of the bimetallic trip device 8 is connected to a (movement) contact arm 13, which cooperates electrically with a fixed contact 14, which in turn is electrical with the magnetic trip device 7, via a wire 11, with which the arc guide plate (39) is electrically and mechanically connected connected is. The closed current path thus runs from the screw terminal 9 via the bimetal release device 8, the stranded wire 11, the contact arm 13, the fixed contact 14, the magnetic release device 7 to the screw terminal 10.

In order to control the movement of the contact arm 13, it is attached to the switching lock 6 with its fastening end 15. This consists in particular of a pivot lever 17 rotatably mounted in the switch housing 2 by means of an axis 16 and a separately mounted release lever 18. The latter is mounted on the pivot lever 17 at a distance from its axis 16 by means of a separate pivot axis 19 and forms a two-link chain with the pivot lever 17. By a torsion spring 20 guided around the axis of rotation 19 a counterclockwise torque is exerted on the unlatching lever 18 opposite the pivoting lever 17. As a result, the unlatching lever 18 is supported by means of a web 21 on a contact projection 22 which protrudes from the side wall of the housing against the switching mechanism 6. On the upper side 23 of the switch lock 6 there is a latching point in the form of a detent 24 protruding upwards from the unlatching lever 18, on which the latch 25 side of a transmission bracket 26, which is fastened with its second end 27 to the interior area of the handle 4 in such a way, that it is guided around the axis 28 of the handle 4 when it is pivoted and, in the switched-on position together with the inner part of the handle 4, forms a toggle lever which is locked beyond the dead center. The switch lock end 25 of the transmission bracket is guided in a longitudinal groove 29 of the pivot lever 17 during the switch-on, switch-off and release movement.

The magnetic and bimetallic release devices 7, 8 act on the lower end 30 of the unlatching lever 18 designed as a one-armed lever, a plunger 31 of the magnetic release device 7 acting directly on the lower end and the movement of the pivoting end 12 of the bimetallic release device 8 by means of a connecting slide 32 lower end 30 of the release lever 18 is transmitted.

The fastening end 15 of the contact arm 13 is provided with an L-shaped bend 33 which is pressed into a form-fitting recess 35 of the pivot lever 17 by means of a compression spring 34.

In the lower area of the circuit breaker an extinguishing chamber antechamber 36 is provided which is on one side of an extinguishing chamber 37 is limited. An arc guide plate 39 leads from the underside 38 of the quenching chamber 37 in the direction of the switch lock and forms a stop 40 for the contact arm 13 which is in the release position

An adjusting device 42 provided with an adjusting screw 41 is used to adjust the bimetallic release device 8.

Function of the circuit breaker:

In the switched-off position shown in FIG. 1, the handle 4 is in a position tilted to the left, as a result of which the transmission bracket 26 is retracted to the right relative to the latching lug 24. In this initial position, the locking lug 24 completely covers the width of the longitudinal groove 29, so that when the locking lug 24 is acted upon by the end 25 of the transmission bracket 26, a secure latching occurs. If the handle 4 is brought into the switch-on position (via the middle position shown in FIG. 2 to the end position shown in FIG. 3), the following movements take place in the switch lock:

a) The pivot lever 17 is rotated counterclockwise about its axis 16 and the force of the compression spring 34 and takes with it the unlatching lever 18 mounted on the axis of rotation 19, which performs a downward sliding rotary movement due to its abutment on the projecting projection 22. This relative movement between the pivot lever 17 and the unlatching lever 18 leads to the catch 24 continuously withdrawing from the longitudinal groove 29 during the switch-on pivoting movement until it only partially in the switched-on position of the catch is covered wisely. This position of the detent 24 is referred to as the critical release position.

b) After the pivot lever 17 has undergone approximately half its rotary movement, the contact arm 13 is already in contact with the fixed contact 14. In this contact position, it performs a downward sliding rotary movement around the end of the L-shaped bend 33, which is supported at the corresponding point in the form-fitting recess 35. The further the handle is pivoted into the switch-on position, the more the L-shaped bend or the fastening end 15 of the contact arm 13 lifts out of the form-fitting recess against the force of the spring 34, which results in the downward rotating sliding movement. Thus, when switching on, a contact cleaning is carried out by mutual sliding action between the contact arm 13 and the silver-plated contact surface of the fixed contact 14.

In the embodiment shown in Fig. 3, the second end 27 of the transmission bracket 26 has migrated beyond the straight connecting line (dead center line) between the center of the axis 28 and the end 25 and thus exerts a clockwise torque on the handle, which is caused by the force the compression spring 34 is generated via the latching point (locking lug 24).

By one of the triggering devices 7.8, the lower end 30 of the Entklinkungshebels 18 only slightly charged, the detent 24 is the end 25 of the transfer strap 26 free so that it a sudden snap-back of the two levers (pivoted lever 17, release lever 1 ₈₎ comes and the switch contact surface between Contact arm 13 and fixed contact 14 is torn open. A resulting arc is dissipated into the quenching chamber 37 via the arc guide plate 39. Due to the prevailing spring forces of the springs 34 and a further torsion spring 44 located in the handle 4, the switching lock 6 will return to its switch-off position in time before the handle 4. The handle 4, which rotates somewhat more slowly, pulls the transmission bracket 26 back into the switched-off position, its end 25 sliding over a sliding inclined surface 43 on the rear side of the locking lug 24 and pressing it briefly downward against the force of the torsion spring 20.

(File 83634) Lindner GmbH Factory of electric lamps and apparatus Reference symbol list

• 1 circuit breaker
• 2 switch housings
• 3 top
• 4 handle
• 5 interior
• 6 key switch
• 7 magnetic release device
• 8 bimetal release device
• 9 screw terminal
• 10 screw terminal
• 11 strands
• 12 swiveling end
• 13 contact arm
• 14 fixed contact
• 15 fastening end
• 16 axis
• 17 swivel levers
• 18 release lever
• 19 axis of rotation
• 20 torsion spring
• 21 bridge
• 22 Investment advantage
• 23 top of v. 6
• 24 latch
• 25 end
• 26 transmission bracket
• 27 second end
• 28 axis
• 29 longitudinal groove
• 30 bottom end
• 31 plungers
• 32 connecting slider
• 33 L-turn
• 34 compression spring
• 35 form-fitting recess
• 36 extinguishing chamber anteroom
• 37 arcing chamber
• 38 bottom of 37
• 39 Arc baffle
• 40 stop
• 41 adjusting screw
• 42 Adjustment device
• 43 Sliding surface
• 44 Another torsion spring

Claims (14)

1. Manually operated circuit breaker with the following features: - The circuit breaker (1) has a magnetic and / or bimetallic release device (7, 8) acting on a switching lock (6) which can be locked and unlocked with a handle (4), - The switch lock (6) consists essentially of a pivoted lever (17) rotatably mounted in a switch housing (2) and a release lever (18) cooperating with it, - The swivel lever (17) transmits the swivel movement of the handle (4) to an elastically coupled to it, in the switch housing (2) pivotable, with a fixed contact (14) interacting contact arm (13), - The unlatching lever (18) is acted upon by the magnet and / or bimetallic release device (7, 8) and is provided with a latching point for a transmission bracket (26) which acts like a knee joint between the handle (4) and the switching mechanism (6), characterized by the following features: - The unlatching lever (18) is designed as a lever lying parallel to the pivot lever (17), is mounted on a separate axis of rotation (19) on the pivot lever (17) at a distance from its axis (16) and forms together with the pivot lever (17) a two-link chain, - The unlatching lever (18) is supported in its central region (web 21) on a housing-fixed contact projection (22) which is arranged at a distance from the axis (16) of the pivoting lever (17), - The transmission bracket (26) is positively guided with its switching lock-side end (25) in a longitudinal groove (29) of the pivoting lever (17) in the direction of action and acts directly on the latching point (24) of the unlatching lever (18) which projects upwards , - The locking lug (24) protrudes during the switch-on pivoting movement of the pivoting lever (17) with a decreasing degree of overlap into the path of movement of the transmission bracket (26) defined by the longitudinal groove (29) and releases it during the triggering pivoting movement of the release lever (18). 2. Circuit breaker according to claim 1,
characterized,
that the contact arm (13) is mounted exclusively on the pivot lever (17) and is pressed with its fastening end (15) by means of a compression spring (34) into a form-fit recess (35) of the pivot lever (17). 3. Circuit breaker according to claim 2,
characterized,
that the contact arm (13) at its fastening end (15) with an L-shaped angle bend (33) is provided, the inside of the angle of which is acted upon by the compression spring (34). 4. Circuit breaker according to one of the preceding claims,
characterized,
that the contact area of the contact arm (13) slides during the transfer of the handle (4) from the switch-off to the switch-on position with high contact pressure on the fixed contact in the longitudinal direction of the contact arm. 5. Circuit breaker according to one of the preceding claims,
characterized,
that the contact arm (13) is pulled in the longitudinal direction of the contact arm at the start of the transfer of the handle (4) from the switch-on to the switch-off position. 6. Circuit breaker according to one of the preceding claims,
characterized,
that the separate axis of rotation (19) of the unlatching lever (18) is arranged on the side of the pivoting lever (17) facing away from the handle (4). 7. Circuit breaker according to one of the preceding claims,
characterized,
that the locking lug (24) is provided on its rear side facing away from the handle (4) with an inclined sliding surface (43). 8. Circuit breaker according to one of the preceding claims,
characterized, that the locking lug (24) in the switched-on position only partially covers the longitudinal groove (29) in the transverse direction. 9. Circuit breaker according to one of the preceding claims,
characterized,
that the unlatching lever (18) has in its central region a web (21) projecting against a side wall of the housing to act on the contact projection (22), the latter being designed as a housing projection. 10. Circuit breaker according to claim 9,
characterized,
that the back of the web (21) facing away from the contact projection (22) is pressurized by one leg of a torsion spring (20), the other leg of which is supported on the pivot lever (17). 11. Circuit breaker according to one of the preceding claims,
characterized,
that the contact arm (13) protrudes with its free end into a quench chamber antechamber (36). 12. Circuit breaker according to one of the preceding claims,
characterized,
that the contact arm (13) abuts an arc guide plate (39) in the switch-off trigger position, as a result of which the switching lock (6) comes to an indirect stop (40) during the switch-off movement. 13. Circuit breaker according to one of claims 2 to 12,
characterized,
that the compression spring (34) is supported on the switching lock (6) facing the upper end of the arc guide plate (39). 14. Circuit breaker according to one of the preceding claims,
characterized,
that the handle (4) is biased by a further torsion spring (44) inserted into it in the off-release position.

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