EP3767660B1

EP3767660B1 - A switching device

Info

Publication number: EP3767660B1
Application number: EP20183070.0A
Authority: EP
Inventors: Bernd Spritzendorfer; Raffael Zimmel
Original assignee: Eaton Intelligent Power Ltd
Current assignee: Eaton Intelligent Power Ltd
Priority date: 2019-07-16
Filing date: 2020-06-30
Publication date: 2023-08-02
Anticipated expiration: 2040-06-30
Also published as: EP3767660A1; GB201910160D0; DK3767660T3; CN112242273B; GB2585836A; ES2958360T3; CN112242273A; AU2020204320A1

Description

The present disclosure relates to a switching device according claim 1.
In low-voltage switching devices with a manual control button, i.e., having a manually operated element for closing the switched contacts and establishing a conductive current path via the switching device, it is usual that there is a movable switched contact, which is connected mechanically to the manual control button, and which, as the manual control button is actuated, is continually moved closer to a housing-mounted switched contact until both the switched contacts are connected mechanically. The opening of the contact, i.e., the switching-off of the switching device, takes place in accordance with the movement of the corresponding manual control button in the corresponding direction, which results in a continuous disconnection of the contacts. There exists a possibility that a user can maintain the manual control button in an arbitrary intermediate position, keeping the contacts in a correspondingly intermediate position.
If the switching device in question is under electric potential, at a certain distance between the closing switched contacts, an electric arc can be produced. With sufficiently low voltage and with users of electricity that require only small amounts of current to be conducted via the switching device, no problem is generally created as a result.
At higher voltages and currents, e.g., 600 V and 100 A, such an electric arc, which occurs because of an excessively slow manual separation of the contacts, can lead to significant damage to the affected switching device. If there is an accordingly high current flowing via the switching device in question when the disconnection takes place, the slow manual opening of the contacts can lead to an electric arc that can lead not only to a complete loss of the switching device in question, but also to a fire.
There are known devices with a so-called jump switch-off function. With it, the switched contacts are separated rapidly when disconnecting manually, independently of the manner and speed with which the operator actuates the manual control button. However, such jump switch-off functions are common primarily in the field of very large circuit breakers, such as those used in electric substations. Such switching devices have separately charged spring-loaded accumulators, which are used when opening or closing the contacts, wherein the use of this technology in compact switching devices is hardly possible, since an integration of the necessary components is not possible in the correspondingly compact housings.
US 9 953 777 B2 by the applicant describes a switching device with a jump-switch off function in a compact design. Although the mechanism according US 9 953 777 B2 works perfect in most conditions it tend to malfunction in one special case. This special case can only happen in the phase the contacts were closed by actuating the hand switching lever. It is sometimes possible that the contacts are already closed but the engagement area of the connecting rod is not bearing against the projection of the hand switch lever. The reason for this situation is an unfinished movement of the hand switch lever. A further movement of the hand switch lever of a few degrees in the direction to close the contacts would bring the engagement area of the connecting rod in contact with the projection. If the engagement area is in contact with the projection of the hand switching lever it is not possible to open the contacts slowly.
However, if the hand switch lever isn't moved in the direction to close the contacts until the end, and instead is moved in the opposite direction to open the contacts the jump-switch off function according US 9 953 777 B2 would not work. In this special case it would be possible to bring the contacts in any intermediate position between open and closed by moving the hand switching lever. As the contacts were already closed before, an arc would occur between the contacts. As the contacts open slowly or stay fixed in an almost constant distance this arc will not extinguish. As a reason the switch would burn in less than a second, and probably harming at least the person actuating the hand switching lever.
The document US 2017/229260 A1 discloses a switching device according to the preamble of claim 1.
The WO 2015/177144 A1 shows a switching device with a contact which is fixed to the housing and a movable contact. The switching device further comprises a switch lock which has a latch and a latch support.
The EP 0 091 040 A2 shows an excess-current circuit breaker comprising an actuation element for manual switching on/off and a toggle lever element, which is articulated at the housing-internal end of the actuation element.
It is an object of the present invention to overcome the drawbacks of the state of the art by providing a compact switching device with a jump-switch off function which switches off currents reliable independently of the manner and speed with which the operator actuates the manual control button.
According to the invention, this object is solved by the features of claim 1.
As a result, a safe switching-off of the switching device, and thus a safe contact separation, may be accomplished, regardless of the manner and speed with which the user actuates the hand switching lever. The jump-switch off function will be activated in each case the hand switching lever respective the manual control button is turned in a direction for opening the contacts, after the hand switching lever has overstepped a predefined position. This predefined position is not a stationary position of the hand switching lever.
The switching device described can thus have a compact design, with a small number of necessary parts.
Dependent claims describe further preferred embodiments of the invention.
The invention is described with reference to the drawings. The drawings are showing only preferred embodiments.

FIG. 1 a perspective view of the proposed switching device in the switched-off state without the upper housing shell;
FIG. 2 the switching device as shown in FIG. 1 in the switched-on state;
FIG. 3 a vertical view of the arrangement of the switch lock, contact arm, and switching lever of the switching device as shown in FIG. 2, in the switched-on state;
Fig. 4 the arrangement as shown in FIG. 3, in the switched-off state;
Fig. 5 the view according Fig. 4 with a part of the connecting rod cut away;
Fig. 6 the arrangement as shown in FIG. 3, wherein the hand switching lever is moved in the switch-on direction and hold in a first state;
Fig. 7 the view according Fig. 6 with a part of the connecting rod cut away;
Fig. 8 the arrangement as shown in FIG. 3, wherein the hand switching lever is moved in the switch-on direction and hold in a second state;
Fig. 9 the view according Fig. 8 with a part of the connecting rod cut away;
Fig. 10 a detail from Fig. 9 in an enlarged view;
FIG. 11 a part of the switching lever with the connecting rod in an axonometric view;
FIG. 12 the connecting rod according Fig. 11 in a first axonometric view; and
FIG. 13 the connecting rod according Fig. 11 in a second axonometric view.

Fig. 1 and 2 show a particularly preferable execution of a switching device 1 - in particular, a safety switching device - comprising:

a movable contact 4, positioned on a contact arm 3, movably attached to the switching device 1, the movable contact 4 being configured to contact a housing-mounted contact 6 and configured to establish a conductive current path through the switching device 1,
a switch lock 2, connected with the contact arm 3, the switch lock 2 including a latch 20 and a latch support 22, the latch support 22 including a latching location configured to latch the latch 20 to the latch support 22,
a hand switching lever 7, configured to contact the movable contact 4 with the housing-mounted contact 6, the hand switching lever 7 being connected with the contact arm 3,
a connecting rod 10, mounted movably on the latch support 22, an end portion 12 of the connecting rod 10 bearing against a first projection 11 of the hand switching lever 7 when the hand switching lever 7 is in a stationary position in which the movable contact 4 and the housing-mounted contact 6 are in contact,
the connecting rod 10 further comprises an actuating shoulder 29, with the actuating shoulder 29 bearing against a second projection 30 of the hand switching lever 7 when the hand switching lever 7 is in a non-stationary position in which the movable contact 4 and the housing-mounted contact 6 are in contact,
wherein an actuation of the hand switching lever 7, for separating the movable contact 4 from the housing-mounted contact 6, moves the connecting rod 10 and, thus, releases the latching of the latch support 22 to the latch 20.

As a result, a safe switching-off of the switching device 1, and thus a safe separation of the contacts 4, 6, may be accomplished, regardless of the manner and speed with which the user actuates the hand switching lever 7. The jump-switch off function will be activated in each case the hand switching lever 7 respective the manual control button is turned in a direction for opening the contacts 4, 6, after the hand switching lever 7 has overstepped a predefined position. This predefined position is not a stationary position of the hand switching lever 7.
The switching device 1 described can thus have a compact design, with a small number of necessary parts.
FIGS. 3 through 13 show details of the switching device 1 described.
The present invention concerns an electrical switching device 1, wherein it is preferable that the switching device 1 be designed as a safety switching device or a so-called automatic switch. It is preferable that the switching device 1 be designed as a safety circuit breaker or a circuit switch. It is preferable that the switching device 1 be designed as a compact, low-voltage safety switching device. In accordance with the preferred design, the switching device 1 includes at least one trigger 33. FIGS. 1 and 2 show an electromagnetic trigger 33, such as a short-circuit trigger. Additionally, a typically-designed thermal trigger, such as a bi-metallic trigger for overcurrent release, can be provided. Furthermore, it can be provided that the triggers 33 in question be combined.
The switching device 1 has a housing 14 made out of an insulating material, preferably designed as a two-piece part, with two housing halves or shells. FIGS. 1 and 2 show the lower housing half of the housing 14. The upper housing half is not shown.
The switching device 1 has at least one movable contact 4 and at least one housing-mounted contact 6. According to the illustrated preferred execution, the switching device 1 has a so-called double break, thus being provided with two movable contacts 4 and two housing-mounted contacts 6, which are assigned, however, to a single switching path.
If the at least one movable contact 4 has an electrically conductive connection with the at least one housing-mounted contact 6, an electrically conductive current path through the switching device 1 exists. The switching device 1 has two connecting terminals 18, 19. If there is no such electrically conductive connection via the switching device 1, it is regarded as switched-off, i.e., in a switched-off state. If there is such an electrically conductive connection, the switching device is regarded as switched-on, i.e., in a switched-on state. As is customary, the transitions between the two states are accordingly called the switching-on and the switching-off of the switching device 1. Synonymously, the label closed contacts 4, 6 can also be used to refer to the switched-on state, while open contacts 4, 6 can be used for the switched-off state.
The at least one movable contact 4 is arranged on a movable contact arm 3. According to the preferred execution configuration, the contact arm 3 has two movable contacts 4, which are located on corresponding parallel forked extensions of the contact arm 3, which in this execution can also be referred to as contact or switching bridges. The forked extensions are not shown in the figures.
The switching device 1 has a so-called switch lock 2. The switch lock 2 is a mechanical component that controls the movements of the contact arm 3. In the preferable and presented design, besides the contact arm 3, the switch lock 2 also has a latch 20 and a latch support 22. FIGS. 3 to 10 show the corresponding assemblies in different views, in separation from the other components of the switching device 1.
In the representative switch lock 2, the switching lever 7 is connected to the contact arm 3 via a first brace 5 and a bracket 8 affixed to the first brace 5. The first brace 5 is guided via a guiding slot 9 of the pivotably mounted latch 20.
The switching device 1 has a jump switch-off mechanism for manually-actuated rapid separation of the contacts 4, 6. Up to this jump switch-off mechanism, the present switch lock 2 matches (according to the preferred execution configuration) the switch lock 2 as presented in EP 680 661 B1 . The switch lock with the basic embodiment of the connecting rod is shown in US 9 953 777 B2 .
The switch lock 2 has two essentially parallel base plates 25, between which the individual components are mounted. Only one of the base plates is shown in Fig. 1. The latch support 22 is provided with a - not shown - latching location to which the latch 20 can catch so as to form a so-called latching. The latch support 22 is mounted between the two base plates 25 in a way that allows it to swivel. The latch 20 should preferably be a metal part, and is fastened between the base plates 25, also in a way that allows it to swivel. On the latch 20, which is provided with two - not shown - lateral arms, a guiding slot 9 is positioned, by means of which a part of the first (preferably, U-shaped) brace 5 engages. Between the two lateral arms of the latch 20, and on the part of the first brace 5, the bracket 8 is located, which is connected with the movable contact arm 3.
A connecting rod 10 is mounted on the latch support 22, allowing for movement. If the switching lever 7 is set in the stationary position in which the contacts 4, 6 are in contact, the connecting rod 10 is positioned on a first projection 11 of the switching lever 7. It should be noted at this point that the switching lever 7 can also take this position without the contacts 4, 6 actually being in contact, e.g., if the so-called trip-free mechanism of a sealed hand switching lever 7 leads to a release of the switching device 1 and separation of the contacts 4, 6.
It is preferable that the first brace 5 be mounted on or in the first projection 11 of the switching lever 7, as shown. The hand switching lever 7 is rotated in order to switch the switching device 1 on. As a result, the position of the first projection 11 inside the switching device 1 also changes. It is preferable that the switching lever 7 be designed to have multiple components, and the first projection 11 is a part of an internal part of the switching lever 7.
As soon as the switching lever 7 is set to the stable or stationary switched-on position, the connecting rod 10 bears against the projection 11. The stationary position is reached if a further movement of the hand switching lever 7 in the closing contact direction is not possible respective limited by the housing. The connecting rod 10 has a length that is appropriate for this purpose. The connecting rod 10 is mounted on the latch support 22 and can rotate in this position. Furthermore, the connecting rod 10 is attached to the latch support 22, preferably under spring tension, wherein the so-called connecting rod spring 13, which preferably is mounted on the latch support 22 itself, impinges upon the connecting rod 10 in the direction toward the switching lever 7.
The connecting rod 10 is preferably designed as a plastic component and has, according to the present preferable execution configuration, two arms, which run from the support point to the engagement area 12, thus spanning over a gap.
In the stationary switched-on state of the switching device 1, an end portion 12 of the connecting rod 10 bears against the first projection 11 of the switching lever 7, between the switching lever 7 and the latch support 22. It is provided for the connecting rod 10 to be moved from this position by actuating or turning the switching lever 7. The connecting rod 10 then moves the latch support 22, shifting it in a way that releases the latching between the latch support 22 and the latch 20, resulting in a "release" of the switch lock 2, and therefore, the separation of the contacts 4, 6, specifically via the switch lock 2. Using the switching lever 7 to maintain the movable contact 4 in a position close to the housing-mounted contact 6 is, thus, no longer possible. It should be mentioned for the sake of completeness that, from the described switched-on position, an actuation or rotation of the switching lever 7 is possible in one direction only - that which leads to the separation of the contacts 4, 6.
The hand switching lever 7 further comprises a second projection 30, which is preferably arranged on the first projection 11 of the hand switching lever 7. The second projection 30 is especially formed as integral elongation of the first projection 11. The second projection 30 can best be seen in Fig. 10 and 11.
The connecting rod 10 further comprises an actuating shoulder 29, with the actuating shoulder 29 bearing against the second projection 30 of the hand switching lever 7 when the hand switching lever 7 is in a non-stationary position in which the movable contact 4 and the housing-mounted contact 6 are in contact or almost in contact. The actuating shoulder 29 can best be seen in Fig. 10 to 13. According the preferred embodiment the actuating shoulder 29 is arranged on the connecting rod 10 between the end portion 12 of the connecting rod 10 and the movably mounting of the connecting rod 10.
The actuating shoulder 29 enables the jump-off mechanism to work even in cases the end portion of the connecting rod does not engage the first projection. This situation can happen if the switching lever 7 is in a non-stationary position near the switch-on position of the switching lever 7. By moving the switching lever 7 from the off-position to the on-position the second projection 30 will pass the actuating shoulder 29 at one position of the switching lever 7. After passing the actuating shoulder 29 it is not possible to move the switching lever 7 in the direction to open the contacts without activating the jump-off mechanism. This ensures that it is not possible to generate and hold an arc between the contacts 4, 6.
Fig. 6 and 7 show the switch lock 2 with the switching lever 7 in a position immediately before the second projection 30 passes actuating shoulder 29.
Fig. 8, 9 and 10 show the switch lock 2 with the switching lever 7 moved a few degrees further, compared to Fig. 6 and 7. In this position the second projection 30 engages the actuating shoulder 29. Fig. 10 shows an enlarged part of this detail out of Fig. 9.
The length of the connecting rod 10 must be such that it allows for a release of the latching before the contacts 4, 6 are separated. Only FIGS. 2 and 3 show the stationary switched-on state.
The end portion 12 of the connecting rod 10 has a concave engagement area 31 for engaging at the first projection 11 of the hand switching lever 7. It is preferable that the first projection 11 have a recess, in order to avoid premature displacement of the connecting rod 10.
The contact separation occurs in a representative switching device 1, in which the latching is released. As the switching lever 7 is moved back into the switched-off position, the latch 20 is shifted again under the latch support 22, creating a new latching, which is necessary to keep the contacts 4, 6 connected.
It is thus preferable that the housing 14 of the switching device 1 have a - not shown - housing projection in the area of the latch support 22, and that the connecting rod 10 - particularly in the area of its placement on the latch support 22 - have a striking pad 16 for propping up the latch support 22 on the housing projection after the release of the latching. Thus, the first projection 11 cannot push the connecting rod 10 - and, with it, the latch support 22 - too far from the latch 20. It can, therefore, be ensured that, when the switching lever 7 is moved back into the switched-off position, the latch 20 again forms a latching with the latch support 22.
It has proved advantageous that the affected housing projection borders a - not shown - trigger housing opening for connecting the switch lock 2 with an external trigger. Switching devices 1 often have openings in the side walls of the housing 14 in order to functionally connect several such switching devices 1. The production costs can be reduced by supporting the connecting rod 10 on a housing projection, which serves an auxiliary function.
It should be noted that, in the context of the so-called trip-free mechanism, the present switching device 1 can be triggered even if the switching lever 7 is set into the position that corresponds with the switched-on state, with the resulting separation of the contacts 4, 6. The jump switch-off mechanism presented and described here concerns the manually triggered separation of the initially closed contacts 4, 6 by means of actuating the switching lever 7. Despite the term "manual," the actuation can take place via an external mechanical actuator, which moves the hand switching lever 7.

Claims

A switching device (1), comprising:
- a movable contact (4), positioned on a contact arm (3), movably attached to the switching device (1), the movable contact (4) being configured to contact a housing-mounted contact (6) and configured to establish a conductive current path through the switching device (1),

- a switch lock (2), connected with the contact arm (3), the switch lock (2) including a latch (20) and a latch support (22), the latch support (22) including a latching location configured to latch the latch (20) to the latch support (22),

- a hand switching lever (7), configured to contact the movable contact (4) with the housing-mounted contact (6), the hand switching lever (7) being connected with the contact arm (3),

- a connecting rod (10), mounted movably on the latch support (22), an end portion (12) of the connecting rod (10) bearing against a first projection (11) of the hand switching lever (7) when the hand switching lever (7) is in a stationary position in which the movable contact (4) and the housing-mounted contact (6) are in contact,

- wherein an actuation of the hand switching lever (7), for separating the movable contact (4) from the housing-mounted contact (6), moves the connecting rod (10) and, thus, releases the latching of the latch support (22) to the latch (20),
characterized in that

- the connecting rod (10) further comprises an actuating shoulder (29), with the actuating shoulder (29) bearing against a second projection (30) of the hand switching lever (7) when the hand switching lever (7) is in a non-stationary position in which the movable contact (4) and the housing-mounted contact (6) are in contact.
The switching device (1) according to claim 1, characterized in that the second projection (30) of the hand switching lever (7) is arranged on the first projection (11) of the hand switching lever (7).
The switching device (1) according to claim 1 or 2, characterized in that the actuating shoulder (29) is arranged on the connecting rod (10) between the end portion (12) of the connecting rod (10) and the movably mounting of the connecting rod (10).
The switching device (1) according to one of the claims 1 to 3, characterized in, that the switching device (1) further comprises a first brace (5), mounted on the first projection (11) of the hand switching lever (7).
The switching device (1) according to one of the claims 1 to 4, characterized in that the end portion (12) is embodied as a concave engagement area (31) configured to engage at the first projection (11) of the switching lever (7).
The switching device (1) according to one of the claims 1 to 5, characterized in that the connecting rod (10) is mounted on the latch support (22) and can rotate in this position.
The switching device (1) according to one of the claims 1 to 6, characterized in that the switching device (1) further comprises a connecting rod spring (13), mounted on the latch support (22), the connecting rod spring (13) impinging upon the connecting rod (10) in a direction toward the switching lever (7).
The switching device (1) according to one of the claims 1 to 6, characterized in that the switching device (1) further comprises a housing (14) including a housing projection (15) in an area of the latch support (22), wherein the connecting rod (10) includes a striking pad (16) configured to prop up the latch support (22) on the housing projection (15).
The switching device (1) according to claim 8, characterized in that the housing projection (15) borders a trigger housing opening (17) configured to connect the switch lock (2) with an external trigger.
The switching device (1) according to one of the claims 4 to 9, characterized in that the switching lever (7) is connected to the contact arm (3) via the first brace (5) and a bracket (8) affixed to the first brace (5), and wherein the first brace (5) is guided via a guiding slot of the latch (20).
The switching device (1) according to one of the claims 1 to 10, characterized in that the switching device (1) is configured as a safety switching device including the housing-mounted contact (6) and the movable contact (4).
The switching device (1) according to one of the claims 8 to 11, characterized in that the striking pad (16) is disposed in a placement area of the connecting rod (10) on the latch support (22).
The switching device (1) according to one of the claims 1 to 12, characterized in that the latch (20) is pivotably mounted.