Linkage device for electrical switch assembly and electrical switch assembly comprising linkage device

Abstract

The invention relates to a linkage device for an electrical switch assembly and an electrical switch assembly including the linkage device. A linkage device adapted to control two electrical switches comprises a main control shaft member (4), an actuation system comprising a first actuation member (61) for actuating a control shaft (104) of a first electrical switch (100) and a second actuation member (62) for actuating a control shaft (204) of a second electrical switch (200). The mechanism of the linkage device is provided with a torque limiting connection for each electrical switch, where the torque limiting connection is adapted to be released during a disconnection event if the torque applied to the actuating member exceeds a predetermined limit value. The linkage device comprises a stop member system adapted to cooperate with the linkage arm system for preventing the main control shaft member (4) from rotating to the off position when the torque limiting connection of at least one linkage arm of the linkage arm system is in the release position.

Description

Technical Field

[0001] The present invention relates to a linkage device for an electrical switch assembly and to an electrical switch assembly comprising the linkage device. Background Art

[0002] In many cases, electrical switch assemblies need to have a reliable position indication, which means that a main control shaft member of the electrical switch assembly must be prevented from moving to its off position if at least one pole of the electrical switch assembly is not in the open position.

[0003] The known multi-pole electrical switch assembly comprises two electrical switches and a linkage device suitable for controlling the two electrical switches. Here, the multi-pole electrical switch assembly is a six-pole or eight-pole assembly. Summary of the invention

[0004] The object of the present invention is to provide a linkage device for a multi-pole electrical switch assembly, so that the linkage device has a reliable position indication. The object of the present invention is achieved by the following linkage device.

[0005] The invention is based on the idea of ​​providing a reliable position indication by means of a torque limiting connection and a stop member system. The mechanism of the linkage device is provided with a torque limiting connection for each electrical switch, wherein the torque limiting connection is adapted to be released during a disconnection event if the torque applied to an actuating member exceeds a predetermined limit value, wherein the actuating member is a member of a control shaft adapted to actuate one of the electrical switches. The stop member system is adapted to prevent a rotation of the main control shaft member to the off position when at least one of the torque limiting connections is in the released position.

[0006] An advantage of the linkage device of the present invention is that the linkage device provides a reliable position indication. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Hereinafter, the present invention will be described in more detail by way of preferred embodiments with reference to the accompanying drawings, in which

[0008] Figure 1 An electrical switch assembly is shown, the electrical switch comprising a linkage device according to an embodiment of the present invention and two electrical switches connected to the linkage device;

[0009] Figure 2 Shown in disassembled state Figure 1 Electrical switch assembly;

[0010] Figure 3 Shows Figure 1 Exploded view of the linkage equipment;

[0011] Figure 4 Shows Figure 1 A first linkage arm of a linkage device;

[0012] Figure 5A Shows the off state Figure 1 The mechanism of the linkage device;

[0013] Figure 5B Shows the on state Figure 1 The mechanism of the linkage device; and

[0014] Figure 5C Shown in the case where the stop member system prevents the rotation of the main control shaft member to the off position Figure 1 The mechanism of the linkage device. DETAILED DESCRIPTION

[0015] Figure 1 It shows an electrical switch assembly including a linkage device, a first electrical switch 100 and a second electrical switch 200. The first electrical switch 100 and the second electrical switch 200 are arranged in parallel and connected to the linkage device.

[0016] Figure 2 Shown in disassembled state Figure 1 The linkage device includes a frame 2, a main control shaft member 4 and an actuation system. The first electrical switch 100 includes a control shaft 104, which can rotate between an on position and an off position relative to the frame of the first electrical switch. The second electrical switch 200 includes a control shaft 204, which can rotate between an on position and an off position relative to the frame of the second electrical switch. The first electrical switch 100 and the second electrical switch 200 are both three-pole switches. The electrical switch assembly is a six-pole assembly.

[0017] The main control shaft member 4 is rotatable between an on position and an off position relative to the frame 2. The main control shaft member 4 is adapted to be rotated from the on position to the off position in a disconnection event. The main control shaft member 4 is adapted to control the control shaft 104 of the first electrical switch 100 and the control shaft 204 of the second electrical switch 200.

[0018] Figure 3 Shows Figure 1 In addition to the actuation system, Figure 3 The linkage arm system and the stop member system of the linkage device are shown.

[0019] The actuation system comprises a first actuation member 61 for actuating the control shaft 104 of the first electrical switch 100 and a second actuation member 62 for actuating the control shaft 204 of the second electrical switch 200 .

[0020] Each of the first actuation member 61 and the second actuation member 62 is rotatable between the first position and the second position of the brake member relative to the frame 2. The rotation axes of the main control shaft member 4, the first actuation member 61 and the second actuation member 62 are parallel to each other. In addition, the rotation axes of the main control shaft member 4, the first actuation member 61 and the second actuation member 62 are located on the same plane. The main control shaft member 4 is located between the first actuation member 61 and the second actuation member 62.

[0021] Each of the first actuation member 61 and the second actuation member 62 includes a shaft hole adapted to partially receive a control shaft of a corresponding electrical switch so that the actuation member can rotate the received control shaft.

[0022] The linkage arm system mechanically connects the main control shaft member 4 to the first actuation member 61 and the second actuation member 62, so that under normal operating conditions of the linkage device, the rotation of the main control shaft member 4 from the on position to the off position moves the first actuation member 61 and the second actuation member 62 from their first position to their second position. The linkage arm system is suitable for transmitting torque from the main control shaft member 4 to the first actuation member 61 and the second actuation member 62.

[0023] The linkage arm system includes a first linkage arm 51 and a second linkage arm 52, the first linkage arm 51 is between the main control shaft member 4 and the first actuation member 61, and the second linkage arm 52 is between the main control shaft member 4 and the second actuation member 62. The main control shaft member 4 is connected to each linkage arm by a corresponding drive pin 94, and the central axis of the drive pin 94 is stationary relative to the main control shaft member 4 and the linkage arm. One of the drive pins rotatably connects the main control shaft member 4 and the first linkage arm 51, and the other of the drive pins rotatably connects the main control shaft member 4 and the second linkage arm 52.

[0024] There is a torque limiting connection between the first linkage arm 51 and the first actuation member 61, and between the second linkage arm 52 and the second actuation member 62. The torque limiting connection is adapted to be released during a disconnection event if the torque applied to the actuation member by the linkage arm exceeds a predetermined limit value. Therefore, if the torque applied to the first actuation member 61 by the first linkage arm 51 exceeds a predetermined limit value, the torque limiting connection between the first linkage arm 51 and the first actuation member 61 is adapted to be released during a disconnection event. Similarly, if the torque applied to the second actuation member 62 by the second linkage arm 52 exceeds a predetermined limit value, the torque limiting connection between the second linkage arm 52 and the second actuation member 62 is adapted to be released during a disconnection event.

[0025] The predetermined limit value for torque applied to the actuating member by the linkage arm is 250% of the nominal torque required to actuate the control shaft of the corresponding electrical switch. In an alternative embodiment, the predetermined limit value for torque applied to the actuating member by the linkage arm is greater than or equal to 150% of the nominal torque required to actuate the control shaft of the corresponding electrical switch.

[0026] Figure 4 A first linkage arm 51 is shown. The first linkage arm 51 has a first end 501 and a second end 502. A hole adapted to receive the drive pin 94 is located adjacent the first end 501.

[0027] The second linkage arm 52 is identical to the first linkage arm 51. Furthermore, the first actuation member 61 is identical to the second actuation member 62.

[0028] The stop member system is adapted to cooperate with the linkage arm system to prevent rotation of the main control shaft member 4 to the off position when the torque limiting connection of at least one linkage arm of the linkage arm system is in a released position relative to the corresponding actuating member. The stop member system comprises a first stop member 81 adapted to contact the second end of the first linkage arm 51 and a second stop member 82 adapted to contact the second end of the second linkage arm 52. The first stop member 81 and the second stop member 82 are stationary members relative to the frame 2. Figure 3 It is shown that the first stop member 81 and the second stop member 82 protrude from the inner wall of the frame 2 .

[0029] exist Figure 3 In the illustrated embodiment, the first stop member 81 and the second stop member 82 are an integral part of the frame 2 and they are formed by the same injection molding process as the frame 2. In an alternative embodiment, the first stop member and the second stop member comprise separate members connected to the frame.

[0030] The torque limiting connection includes an elongated slot 10 provided in the first linkage arm 51 and an actuating pin 96 connected to the first actuating member 61 and received in the elongated slot 10 .

[0031] The linkage device includes two actuating pins 96, one of which rotatably connects the main control shaft member 4 and the first linkage arm 51, and the other of which rotatably connects the main control shaft member 4 and the second linkage arm 52. Since the connection between the first linkage arm 51 and the first actuating member 61 is similar to the connection between the second linkage arm 52 and the second actuating member 62, only the connection between the first linkage arm 51 and the first actuating member 61 will be discussed herein.

[0032] The actuation pin 96 is spaced apart from the rotational axis of the first actuation member 61 and extends parallel to the rotational axis of the first actuation member 61. The central axis of the actuation pin 96 is stationary relative to the first actuation member 61.

[0033] The elongated slot 10 has a first portion 110 and a second portion 120 separated by a narrow portion 115. The elongated slot 10 extends in a straight line. The first portion 110 of the elongated slot 10 is further away from the connection between the main control shaft member 4 and the linkage arm than the second portion 120 of the elongated slot 10. The first portion 110 of the elongated slot 10 is located near the second end 502 of the first linkage arm 51.

[0034] In normal operating conditions, the actuating pin 96 is received in the first portion 110 of the elongated slot 10. The torque limiting connection is adapted to be released such that the actuating pin 96 moves from the first portion 110 to the second portion 120 through the narrow portion 115.

[0035] In the longitudinal direction of the first linkage arm 51, the size of the first portion 110 of the elongated slot 10 is smaller than the size of the second portion 120 of the elongated slot 10. The longitudinal direction of the first linkage arm 51 extends in a plane perpendicular to the rotation axis of the main control shaft member 4. Figure 4 In the figure, the longitudinal direction of the first linkage arm 51 is the horizontal direction.

[0036] The actuating pin 96 has a circular cross section. The first portion 110 of the elongated slot 10 is dimensioned to allow a lateral movement of the actuating pin 96 of less than or equal to 10% of the diameter of the actuating pin 96 under normal operating conditions of the linkage device. The lateral movement occurs in a plane perpendicular to the axis of rotation of the main control shaft member 4. In another embodiment, the first portion of the elongated slot is dimensioned to allow a lateral movement of the actuating pin 96 of less than or equal to 25% of the diameter of the actuating pin 96 under normal operating conditions of the linkage device.

[0037] In an alternative embodiment where the cross-section of the actuating pin is non-circular, the first portion of the elongated slot is dimensioned to allow lateral movement of the actuating pin in the first portion less than or equal to 10% of the maximum lateral dimension of the actuating pin under normal operating conditions of the linkage. In another alternative embodiment, the first portion of the elongated slot is dimensioned to allow lateral movement of the actuating pin less than or equal to 25% of the maximum lateral dimension of the actuating pin under normal operating conditions of the linkage. In yet another alternative embodiment, the first portion of the elongated slot is dimensioned to prevent lateral movement of the actuating pin under normal operating conditions except for movement caused by a gap between the actuating pin and the first portion of the elongated slot, where the gap is caused by the manufacturing technique used to manufacture the actuating pin and the elongated slot.

[0038] The second portion 120 of the elongated slot 10 is dimensioned to allow lateral movement of the actuating pin 96 in the released position of the torque-limiting connection by greater than or equal to 50% of the diameter of the actuating pin 96. In an alternative embodiment where the cross-section of the actuating pin is non-circular, the second portion of the elongated slot is dimensioned to allow lateral movement of the actuating pin in the released position of the torque-limiting connection by greater than or equal to 50% of the maximum lateral dimension of the actuating pin.

[0039] Figures 5A-5C The operation of the mechanism of the linkage device is shown. Figure 5A The mechanism of the linkage device is shown in the off state. Figure 5B The mechanism of the linkage device is shown in the switched-on state. Figure 5C The mechanism of the linkage is shown with the torque limiting connection of the first linkage arm 51 in the disconnected position relative to the first actuating member 61 and the second end 502 of the first linkage arm 51 in contact with the first stop member 81 preventing rotation of the main control shaft member 4 to the off position.

[0040] exist Figure 5A In the embodiment of the present invention, the main control shaft member 4 is in the off position, and the first actuating member 61 and the second actuating member 62 are in their second positions. One of the drive pins 96 is located in the first portion 110 of the elongated slot 10 of the first linkage arm 51, and the other of the drive pins 96 is located in the first portion 110 of the elongated slot 10 of the second linkage arm 52.

[0041] exist Figure 5B In the embodiment, the main control shaft member 4 is in the on position, and the first actuating member 61 and the second actuating member 62 are in their first positions. Each of the actuating pins 96 is located in the first portion 110 of the corresponding elongated slot 10, such as Figure 5A shown.

[0042] By rotating the main control shaft member 4 90 degrees clockwise, the Figure 5A Status to Figure 5B In response to the main control shaft member 4 rotating 90 degrees clockwise, the first actuating member 61 and the second actuating member 62 both rotate 90 degrees clockwise.

[0043] exist Figure 5C , the main control shaft member 4 is in an intermediate position between the on position and the off position, and the first actuating member 61 and the second actuating member 62 are in an intermediate position between their first and second positions. The intermediate positions of the first actuating member 61 and the second actuating member 62 are different from each other. One of the drive pins 96 is located in the second portion 120 of the elongated slot 10 of the first linkage arm 51, and the other of the drive pins 96 is located in the first portion 110 of the elongated slot 10 of the second linkage arm 52.

[0044] By rotating the main control shaft member 4 counterclockwise, the Figure 5B Status to Figure 5C The intention of the operator of the electrical switch assembly is to perform a disconnect event by rotating the main control shaft member from the on position to the off position. However, during the disconnect event, the torque applied by the first linkage arm 51 to the first actuation member 61 has exceeded the predetermined limit value, and the torque limiting connection between the first actuation member 61 and the first linkage arm 51 has been released.

[0045] The width of the narrow portion 115 of the elongated slot 10 is smaller than the diameter of the actuating pin 96. Therefore, in order to allow the actuating pin 96 to pass through the narrow portion 115, at least one of the narrow portion 115 and the actuating pin 96 must change its shape. In a typical embodiment, the narrow portion deforms the most. The deformation of the narrow portion and the actuating pin is a reversible deformation.

[0046] The length of the narrow portion 115 of the elongated slot 10 is small compared to the length of the second portion 120 of the elongated slot 10. In an embodiment, the length of the narrow portion is in the range of 30-100% of the maximum transverse dimension of the actuating pin. In another embodiment, the length of the narrow portion is in the range of 1.5-5 mm. The length of the narrow portion is the dimension parallel to the direction in which the elongated slot extends.

[0047] There may be several reasons why the torque applied by the first linkage arm 51 to the first actuation member 61 exceeds the predetermined limit. One of the reasons is that at least one contact of the electrical switch controlled by the first actuation member 61 is stuck due to welding caused by a short circuit condition in the electrical switch.

[0048] Figure 5C The main control shaft member 4 is shown having stopped at a position thirty degrees from the off position. In an alternative embodiment, the stop member system is adapted to cooperate with the linkage arm system to stop the main control shaft member to an intermediate fault position located at least 10° from the off position.

[0049] It is obvious to a person skilled in the art that the concept of the invention can be implemented in various ways.The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. A linkage device for an electrical switch assembly, comprising: Frame (2); a main control shaft member (4) rotatable between an on position and an off position relative to the frame (2), wherein the main control shaft member (4) is adapted to be rotated from the on position to the off position in a disconnection event; An actuation system comprising a first actuation member (61) and a second actuation member (62), wherein the first actuation member (61) is used to actuate a control shaft (104) of a first electrical switch (100), and the second actuation member (62) is used to actuate a control shaft (204) of a second electrical switch (200), wherein each of the first actuation member (61) and the second actuation member (62) is rotatable between a first position and a second position of the actuation member; A linkage arm system mechanically connects the main control shaft member (4) to the first actuating member (61) and the second actuating member (62) such that under normal operating conditions of the linkage device, rotation of the main control shaft member (4) from the on position to the off position moves the first actuating member (61) and the second actuating member (62) from their first position to their second position, wherein the linkage arm system comprises a first linkage arm (51) and a second linkage arm (52), the first linkage arm (51) being between the main control shaft member (4) and the first actuating member (61), and the second linkage arm (52) being between the main control shaft member (4) and the second actuating member (62), characterised in that there is a torque limiting connection between the first linkage arm (51) and the first actuating member (61) and between the second linkage arm (52) and the second actuating member (62), wherein the torque limiting connection is adapted to be released during the disconnection event if the torque applied by the linkage arm to the actuating member exceeds a predetermined limit value, The linkage device comprises a stop member system adapted to cooperate with the linkage arm system for preventing the main control shaft member (4) from rotating to the off position when the torque limiting connection of at least one linkage arm of the linkage arm system is in a released position relative to the corresponding actuating member.

2. A linkage device according to claim 1, wherein each linkage arm has a first end (501) and a second end (502), so that the connection between the main control shaft component (4) and the linkage arm is located near the first end (501), and the stop component system includes a first stop component (81) and a second stop component (82), the first stop component (81) is suitable for contacting the second end (502) of the first linkage arm (51), and the second stop component (82) is suitable for contacting the second end (502) of the second linkage arm (52), wherein the first stop component (81) and the second stop component (82) are stationary components relative to the frame (2).

3. A linkage device according to claim 1 or 2, wherein the torque limiting connection includes a slender slot (10) and an actuating pin (96), the slender slot (10) being provided in the linkage arm, the actuating pin (96) being connected to the actuating member and being accommodated in the slender slot (10), wherein the slender slot (10) has a first part (110) and a second part (120) separated by a narrow part (115), wherein under normal operating conditions, the actuating pin (96) is accommodated in the first part (110), and the torque limiting connection is suitable for being released so that the actuating pin (96) moves from the first part (110) to the second part (120) through the narrow part (115).

4. A linkage device according to claim 3, wherein in the longitudinal direction of the linkage arm, the size of the first portion (110) of the slender slot (10) is smaller than the size of the second portion (120) of the slender slot (10), and wherein the longitudinal direction of the linkage arm extends in a plane perpendicular to the rotation axis of the main control shaft component (4).

5. A linkage device according to claim 4, wherein the size of the first portion (110) of the slender slot (10) is designed to allow a lateral movement of the actuating pin (96) less than or equal to 25% of the maximum lateral dimension of the actuating pin (96) under the normal operating condition of the linkage device, and the size of the second portion (120) of the slender slot (10) is designed to allow a lateral movement of the actuating pin (96) greater than or equal to 50% of the maximum lateral dimension of the actuating pin (96) in the released position of the torque limiting connection.

6. The linkage device according to claim 3, wherein the elongated slot (10) provided in each linkage arm extends in a straight line.

7. The linkage device of claim 3, wherein the first portion (110) of the elongated slot (10) is further away from the connection between the main control shaft member (4) and the linkage arm than the second portion (120) of the elongated slot (10).

8. The linkage device according to claim 3, wherein the release of the torque-limiting connection is achieved by deformation of at least one of the narrow portion (115) and the actuating pin (96), wherein the deformation is a reversible deformation.

9. A linkage device according to claim 1 or 2, wherein the central axis of each actuating pin (96) is stationary relative to the corresponding actuating member.

10. A linkage device according to claim 1 or 2, wherein the main control shaft member (4) is connected to each linkage arm by means of a corresponding drive pin (94), and the central axis of the corresponding drive pin (94) is stationary relative to the main control shaft member (4) and the linkage arm.

11. The linkage device according to claim 1 or 2, wherein the rotation axes of the main control shaft member (4), the first actuating member (61) and the second actuating member (62) are parallel to each other.

12. A linkage device according to claim 1 or 2, wherein the stop member system is adapted to cooperate with the linkage arm system for stopping the main control shaft member (4) to an intermediate fault position located at least 10° from the off position.

13. An electrical switch assembly, comprising a first electrical switch (100), a second electrical switch (200) and a linkage device according to claim 1 or 2.

14. The electrical switch assembly of claim 13, wherein the predetermined limit value for the torque applied by the linkage arm to the actuation member is greater than or equal to 150% of a nominal torque required to actuate a control shaft of a corresponding electrical switch.

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