EP0955657A1 - Latch mechanism for a circuit breaker - Google Patents

Abstract

The electrical protection switch is coupled to a lock mechanism that prevents operation when activated. The lock unit has a main body (5) in which there is a linkage (15) arrangement . This is actuated by an element (11) that projects through the housing cover plate (8).

Description

TECHNICAL AREA

The present invention relates to a switch lock for an electrical circuit breaker with two switch positions on both sides of a zero position, which in particular has a multipole design and can be used, for example, as a motor protection switch with the switch positions "off", "forward" or "reverse".

STATE OF THE ART

Corresponding motor protection switches are known, but there is an ongoing need to improve them. Among other things, improvements are being sought with regard to a simpler structure and a more rational and therefore less expensive production using automatic assembly machines as far as possible. It depends on the number of lower parts of the switch lock and how they can be put together and brought into engagement with each other. Assembly from only one direction is particularly advantageous.

PRESENTATION OF THE INVENTION

Against the background of this endeavor, the invention provides a switch lock for a circuit breaker at the beginning mentioned type created, the features of which are specified in claim 1.

• der Drehhebel
  • von Hand betätigbar,
  • an einer ortsfesten Drehhebelachse gelagert ist und
  • mit dem Zwischenstück gelenkig verbunden ist;
• das Zwischenstück
  • zusammen mit dem Drehhebel einen Kniehebel mit zwei Wirkenden bildet und
  • den Schalthebel in den beiden Schaltstellungen alternativ mit den beiden Wirkenden beaufschlagt;
• der Schalthebel
  • zwei Enden hat,
  • im Bereich seines einen Endes mit dem Klinkenhebel gelenkig verbunden und
  • im Bereich seines anderen Endes mit der Schaltstange gekoppelt ist;
• der Klinkenhebel
  • an einer gegen die Wirkung einer ersten Feder in einer Längsrichtung weg von der Drehhebelachse verschiebbaren Klinkenhebelachse gelagert und
  • gegen Verdrehung um die Klinkenhebelachse verklinkbar ist; und
• die Schaltstange
  • quer zur Längsrichtung verschiebbar ist und
  • direkt oder indirekt durch zwei zweite, gegeneinander wirkende Federn in eine der Nullstellung entsprechende Nullposition gedrängt wird.

The switching lock according to the invention accordingly has a rotary lever, a switching lever, an intermediate piece, a ratchet lever and a switching rod, wherein

• the rotary lever
  • can be operated by hand,
  • is mounted on a fixed rotary lever axis and
  • is hinged to the intermediate piece;
• the intermediate piece
  • together with the rotary lever forms a toggle lever with two ends and
  • the switching lever in the two switching positions alternatively acted upon by the two actors;
• the gear lever
  • has two ends,
  • in the area of its one end articulated with the ratchet lever and
  • is coupled to the shift rod in the area of its other end;
• the ratchet lever
  • mounted on a pawl lever axis which can be displaced in a longitudinal direction away from the action of a first spring, and
  • is lockable against rotation about the ratchet lever axis; and
• the shift rod
  • is displaceable transversely to the longitudinal direction and
  • is pressed directly or indirectly into a zero position corresponding to the zero position by two second springs acting against each other.

The key switch according to the invention is characterized above all by a minimum of parts and by the fact that it can be mounted from only one direction. The so-called free trip is guaranteed. Conversely, switching on is not possible as long as the key switch or its latch lever is not latched.

BRIEF EXPLANATION OF THE FIGURES

Fig. 1

einen dreipoligen Schutzschalter mit einem Schaltschloss nach der Erfindung in Explosionsdarstellung;

FIG. 2-5

schematisch das Schaltschloss in verschiedenen Schaltstellungen;

Fig. 6

schematisch das Schaltschloss in einer Auslösestellung; und

Fig. 7

schematisch das Schaltschloss mit einer besonderen Ausbildung des Drehhebels, des Klinkhebels sowie der Verklinkung des Klinkenhebels.

The invention will be explained in more detail below on the basis of exemplary embodiments in connection with the drawing. Show it:

Fig. 1

a three-pole circuit breaker with a switch lock according to the invention in an exploded view;

FIG. 2-5

schematically the key switch in different switching positions;

Fig. 6

schematically the key switch in a release position; and

Fig. 7

schematically the key switch with a special design of the rotary lever, the latch lever and the latching of the latch lever.

In the figures, identical parts are provided with the same reference symbols.

WAYS OF CARRYING OUT THE INVENTION

1 shows an exploded view of a three-pole electrical circuit breaker, which can be used in particular as a motor protection switch, with two switch positions on both sides of a zero position. The zero position preferably corresponds to the off position of the circuit breaker and the two switch positions on both sides of the zero position two Switch-on positions, for example in the sense of forward and reverse running of a connected electric motor.

The circuit breaker has a modular structure on several levels one above the other. 1 denotes a lower housing part in the form of a flat, open shell. Arranged in this are three double switch contacts 2 which can be switched between a middle open position and two on positions arranged on either side thereof. Furthermore, the lower housing part 1 houses a unit 3 which is used to detect the switch contacts 2 in the two on positions flowing currents, which serves between these existing voltages and for the generation of control voltages from these quantities. Finally, a switching rod 4 which is displaceable in its longitudinal direction and also carries parts of the switching contacts 2 is also arranged in the housing part 1. By shifting the switching rod 4, the switching contacts 2 can be brought from a middle open position into two on positions arranged on both sides thereof.

In a further housing part 5, which is also designed as an open top shell, a switching lock, designated overall by 6, is arranged. An undervoltage relay 7, which is electrically coupled to the unit 3, is used for latching and unlatching the switching lock 6.

The circuit breaker 1 is closed at the top by a cover plate 8. The cover plate 8 can be screwed to the upper housing part 5 by means of screws 9 and this can be screwed to the lower housing part 2, all parts of the circuit breaker 1 being fixed. The circuit breaker 1 is completely from above, i.e. Can be assembled from one direction.

Through an opening 10 in the cover plate 8, an actuating button 11 protrudes upward (outside), which is part of a rotary lever 12 of the key switch 6. The rotary lever 12 is in the lid opening 10 via the actuating head 11 and thus overall fixed to the housing (rotary lever axis). The rotary lever 12 can be pivoted by hand via the actuating button 11.

In rotary engagement with a hole 13 in the rotary lever 12 is a pin 14 of a triangular intermediate piece 15, which in turn engages in an approximately trapezoidal recess 16 in a shift lever 17, pivotable therein.

At its lower end, the shift lever 17 is provided with a pin 18 which is rotationally engaged with a hole 19 in a ratchet lever 20. At its lower end, the pawl lever 20 has a cam 21, which rests in a recess 22 of a leaf spring 23, which is arranged in a stationary manner in the upper housing part 5 in a manner not shown. A molding 24 directed against the undervoltage relay 7 on the pawl lever 20 forms, together with the armature 25 of the undervoltage relay 7, a pawl arrangement which can be latched when the armature 25 is attracted or is held in the latched state and unlatched when the armature 25 falls. In the unlatched state, the pawl lever 20 is free to pivot its cam 21 (pawl lever axis) resting in the recess 22 of the leaf spring 23. This pivotability is blocked in the latched state. In this state, the latch lever 20 can move somewhat against the action of the leaf spring 23 in a longitudinal direction designated by 26 away from the rotary lever axis 11.

At its upper end, the shift lever 17 engages with a connecting cam 27 of the shift rod 4 which projects upward into the upper housing part 5 in such a way that it can pivot relative to the latter and also shift somewhat in the longitudinal direction 26. As already stated, the shift rod 4 can be displaced in the lower housing part 11 in its longitudinal direction and thus transversely with respect to the longitudinal direction 26. The shift rod 4, its cam 27 or the upper end of the shift lever 17 is further acted upon by two springs 28 and 29 which are directed against each other in their action, which are supported on the housing 5 and push the shift rod 4 into a zero position (FIGS. 2 and 4). In the zero position, the double switching contacts 2 in the lower housing part are in an open position and, starting from this position, can be closed in one direction or the other by shifting the switching rod 4 laterally.

The function of the switching lock 6 formed from the switching lever 12, the intermediate piece 15, the switching lever 17, the ratchet lever 20, the (first) spring 23, the switching rod 4 and the two (second) springs 28 and 29 will be described below with reference to FIGS. 6 are explained in more detail. Figures 2 and 4 show the switch lock 6 in a position which corresponds to the zero position of the circuit breaker 1 and Figures 3 and 5 in positions which correspond to the two switch positions of the circuit breaker 1 on both sides of the zero position. Accordingly, in FIGS. 2 and 4, the rotary head 11 or the shift lever 12 is oriented vertically in the direction of the longitudinal direction 26 and in FIGS. 3 and 5 with respect to this direction 26 to the right (FIG. 3) or to the left (FIG. 5) panned.

The shift lever 12, the intermediate piece 15, the shift lever 17 and the ratchet lever 20 are flat parts, which in the two shift positions on both sides of the zero position in some cases. transfer leverage even differently. In order to clarify this, the respectively effective levers are shown in the form of lines 31-34 in FIGS. 2-5.

In the position of Fig. 2, the triangular intermediate piece 15, which is articulated at its tip to the rotary lever 12 (bearing 13/14), with its base 35 on the base 36 of the trapezoidal recess in the shift lever 17 and projects with it two lower, rounded corners 37 and 38 into correspondingly rounded corners 39 and 40 of the recess 16. The corners 37, 38 of the intermediate piece 15 can alternatively be rotated in the corners 39, 40 of the recess 16.

With regard to the switching position of FIG. 3, it should first be assumed in FIG. 2 that the lever chain 31 - 34 between the bearing 13/14 and the bearing 18/19 via the left corner 37/39 of the intermediate piece 15 or the Recess 16 runs. It is also assumed that the ratchet lever 20/34 is locked and is therefore locked in rotation. If the rotary lever 12/31 and with it the bearing 13/14 on the circular arc 41 is pivoted to the right (direction of rotation) by actuating the rotary knob 11, the intermediate piece 15 is also forced to pivot as well, namely about its lower left corner 37 to the left. The lower right corner 38 of the intermediate piece 15 pivots out of the corner 40 of the trapezoidal recess 16. Since the rotary lever 12/31 forms a toggle lever together with the intermediate piece 15/32, which is moved here via its extended position (dead center), the intermediate piece or its momentarily active lever 32 exerts pressure on the lower left corner 39 of the trapezoidal recess 16 in gear lever 17/33 and also forces it to move with it. The shift lever 17/33 does this on the one hand by pivoting to the left around the bearing 18/19, taking the shift rod 4 against the action of the second spring 28; on the other hand, the shift lever 17/33 temporarily dodges against the action of the first spring 23 with its lower end (bearing 18/19). After passing through the extended position, the first spring 23 supports the further rotation, which is ultimately limited by the fact that the left side leg 42 of the triangular intermediate piece 15 strikes the left side leg 43 of the trapezoidal recess 16. This position is shown in FIG. 3. In this position, the switch rod 4 is shifted to such an extent that the double switch contacts shown in FIG. 1 and designated by 2 are in one of their two mentioned on-positions.

Since the first spring 23 is dimensioned much stronger than the two second springs 28, 29, the switching lock 6 cannot automatically return from the position in FIG. 3 to the zero position in FIG. 2, since this is against the Effect of the first spring 23, the extended position of the knee joint 32/33 would have to be overcome again. The key switch 6 is therefore locked in the position of FIG. 3.

4 and 5 show the same as the switching operation described, starting from the zero position according to FIG. 4 only in the other direction in the other of the two switching positions of the circuit breaker. Here, the lever chain 31-34 runs over the lower right corner 38 of the triangular intermediate piece 15 or the lower right corner 40 of the trapezoidal recess 16 in the shift lever 17. Its effective lever arm 33 extends between the bearing 18/19 and these corners 38/40 . In the stable position of FIG. 5, the triangular intermediate piece 15 strikes, this time with its right side leg 44 on the right side leg 45 of the trapezoidal recess 16.

As can be seen, the intermediate piece 15 in the above-described embodiment has an alternative function with respect to the two switching positions of FIGS. 3 and 5. Together with the rotary lever 12/31, the intermediate piece 15 forms a toggle lever with two ends, which are formed by the two lower corners 37 and 38. The two corners 37 and 38, on the other hand, again represent bearing axles. In order for this to be possible, the two corners 37 and 38 must not be firmly connected to the shift lever 17. However, this is ensured by the loose engagement of the two corners 37 and 38 described in the lower corners 39, 40 of the trapezoidal recess 16 in the shift lever 17. The double function of the intermediate piece 15 and the special way in which it interacts with the shift lever 17 advantageously saves on parts which would otherwise be required to implement the same functionality. This contributes to a simple and inexpensive construction of the entire lock construction.

As far as the shape of the intermediate piece (15) and the recess (16) is concerned, they do not have to be strict are triangular or trapezoidal. It is sufficient if the mutual shapes are matched to one another in such a way that the function explained above is realized. In particular, it does not matter how the upper edge of the recess is designed in the figures. It is also not necessary to lay the base or the side legs of both parts flat. The intermediate piece could therefore also be star-shaped, for example. Finally, of course, the shift lever could also intervene, for example, in a recess in the intermediate piece. The same applies to the other connections of the functional elements described.

Fig. 6 shows the key switch 6 in a trigger position, as e.g. is reached in the event of a fault from the switching position shown in FIG. 3 under the drive of the tensioned second spring 28. The switch rod 4 can be seen to be pushed back by the spring 28 in the direction of its zero position according to FIG. 3, at least to the extent that the switch contacts 2 acted upon by it could open. This shifting of the 4 was made possible by bypassing the toggle lever locking described and without rotating the rotary lever 12/31 (free release) by releasing the latch 24/25 of the latch lever 20/34. This releases the pawl lever 20/34 to pivot its cam 22, which in turn enables the shift lever 17/33 to yield to the pressure of FIG. 4 and to rotate the bearing 13/14 back at the lower end of the rotary lever 12/31. If, conversely, an attempt is made to switch on the switch from its zero position according to FIG. 3 when the latch is released, only the position shown in FIG. 6 is also reached, which means that the switch cannot be brought into its on-switch position when the latch is released.

Starting from the switch position shown in FIG. 4 with the latch released or starting from the switch position shown in FIG. 5 after releasing the latch, there is a comparable trigger position, the shift lever 17/33 compared to it Position in FIG. 6, however, is offset symmetrically to the right beyond the center also marked by line 26.

FIG. 7 shows specific designs of the rotary lever 12 and of the ratchet lever 20 such that the rotary lever 12 extends up to the ratchet lever 20 and is in contact with a convex radius 46 on a concave radius 47 of the ratchet lever 20. The two radii 46, 47 are designed such that the latch lever 20, if it e.g. as pivoted in Fig. 6, when turning the rotary lever 12 e.g. 6, also forcibly pivoted into its neutral pivot position according to FIG. 2 or FIG. 4, in which it can be latched again. The corresponding formations on the rotary lever 12 and on the ratchet lever 20 can be offset relative to the shift lever 17 and the intermediate piece 15, in the illustration of FIG. 1, in particular be arranged in a plane above these elements. In FIGS. 2-6 they are simply omitted in favor of the better visibility of the shift lever 17 and the intermediate piece 15.

Finally, FIG. 7 also shows a possible type of latching of the latch lever 20, the armature 48 of an undervoltage relay 49 being directly part of the latching.

Claims (13)

1. Switch lock (6) for an electrical circuit breaker (1) with two switch positions on both sides of a zero position and with a rotary lever (12/31), an intermediate piece (15/32), a switch lever (17/33), a latch lever (20 / 34) and a shift rod (4), wherein: - the rotary lever (12/31) - can be operated by hand, - Mounted on a fixed rotary lever axis (11) and - Is articulated to the intermediate piece (15/32); - the intermediate piece (15/32) - Together with the rotary lever (12/31) forms a toggle lever with two ends (37,38) and - The switching lever (17/33) in the two switching positions alternatively acted upon with its two ends (37, 38); - the gear lever (17/38) - has two ends, - In the area of its one end with the ratchet lever (20, / 34) articulated and - Is coupled in the area of its other end with the shift rod (4); - the ratchet lever (20/34) - On a against the action of a first spring (23) in a longitudinal direction (26) away from the rotary lever axis (11) displaceable pawl lever axis (22) and - Can be locked against rotation about the pawl lever axis (22); and - the shift rod (4) - Is displaceable transversely to the longitudinal direction (26) and - Is pressed directly or indirectly by two second, opposing springs (28, 29) into a zero position corresponding to the zero position. 2. Switch lock according to claim 1, characterized in that the rotary lever (12), the intermediate piece (15), the shift lever (17), the ratchet lever (20) and the shift rod (4) are pivotable and / or displaceable in mutually parallel planes . 3. Key switch according to one of claims 1 or 2, characterized in that it is arranged in a flat housing part (5) designed as an open top shell, which can be closed with a cover plate (8). 3. Key switch according to claim 2, characterized in that the rotary lever axis (11) of the rotary lever (12 in an opening (10) of the cover plate (8) is mounted. 4. Switch lock according to one of claims 1-3, characterized in that the intermediate piece (15) in a recess (16) in the switching lever (17) engages pivotally therein. 5. Key switch according to claim 4, characterized in that the intermediate piece (15) essentially in the form of a triangle with a base (35), two side legs (42, 44) and two corners connecting the base (35) with the side legs (37, 38) has that it engages with the rotary lever (12) in the region of its tip opposite the base and that the two actors are formed by its two mentioned corners (37, 38). 6. Key switch according to claim 4 or 5, characterized in that the recess (16) in the switching lever (17) is substantially trapezoidal, a base (36) and two side legs (43, 45) and two corners connecting the base with the side legs (39.40). 7. Switch lock according to claim 6, characterized in that the intermediate piece (15) with its two corners (37, 38) engages in the corners (39, 40) of the recess (16) in a precisely fitting manner. 8. Key switch according to claim 7, characterized in that the intermediate piece (15) in the recess (16) alternatively in its two corners (39, 40) is pivotable about one of its corners (37, 38). 9. Key switch according to claim 8, characterized in that the intermediate piece (15) in the zero position with its base (35) on the base (36) of the recess (16) and in the two switch positions aside alternatively with one of its two lateral positions Leg (42,44) strikes one of the side legs (43,45) of the recess (16). 10. Key switch according to one of claims 1-9, characterized in that the rotary lever (12) with the latch lever (20) is in contact and in such a way that it the latch lever (20) from a position pivoted relative to the longitudinal direction (26) when switching to the zero position in a latching position parallel to the longitudinal direction (26). 11. Switch lock according to one of claims 1-10, characterized in that the latching of the latch lever (20) is carried out by an undervoltage relay (49), the armature (48) of the undervoltage relay preferably being part of the latching and the latching by the armature falling off is solved. 12. Switch lock according to one of claims 1-11, characterized in that the switching rod (4) for actuating at least one switching contact (3) of the circuit breaker (1) is formed during its displacement.

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