An operating mechanism for simultaneously opening and closing at least two contacts

Abstract

To provide an operation mechanism for opening and closing at least two contact points at the same time.SOLUTION: An operation mechanism comprises: a bridge main body having a slender contact surface constructed so as to be contacted to an operation rod of two contact parts; a first reaction force arm in which one end is hinged to a base frame and the other end is hinged to the bridge main body; a second reaction force arm in which the one end is hinged to the base frame, and the other end is hinged to the bridge main body; a rod mechanism of two links; and a cam that is a cam 13 arranged on a shaft 14 which is adjacently arranged to rod mechanisms 28 and 29, and is extended in parallel to a hinge shaft of each rod mechanism, and in which the cam contacts to the hinge shaft of the first end part of the two links in an operation.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an actuation mechanism for simultaneously opening and closing at least two contacts. [Background technology]

[0002] In medium-voltage switchgear, it is usually necessary to simultaneously open and close three contacts for three phases. The contacts are usually provided in the form of vacuum circuit breakers, the switching speed of which must be within certain limits in order to operate reliably. Summary of the Invention [Problem to be solved by the invention]

[0003] The actuating mechanism is known to open and close the contact portion, and includes a base frame and a bridge body with an elongated contact surface configured to extend longitudinally over and contact the actuating rod of the contact portion. A rod mechanism is provided to open and close the contact portion by pushing the bridge body up and down.

[0004] However, the rod mechanism is complex, using multiple links hinged together to achieve reliable bridge body movement so that the contacts are opened and closed simultaneously. However, this complexity increases manufacturing costs and the likelihood of misalignment, as each part must be precisely manufactured. [Means for solving the problem]

[0005] It is therefore an object of the present invention to reduce or even eliminate the above-mentioned disadvantages.

[0006] This object is achieved according to the invention by means of an actuating mechanism for simultaneously opening and closing at least two contact parts, the actuating mechanism comprising: a base frame; a bridge body having an elongated contact surface having a length and a width, the elongated contact surface configured to extend longitudinally over and contact the actuation rods of the at least two contact portions; a first reaction arm extending substantially parallel to the length of the elongated contact surface, the first reaction arm being hinged at one end to the base frame and at the other end to the bridge body; a second reaction arm extending parallel to the first reaction arm in a direction perpendicular to the elongated contact surface for a distance of the first reaction arm, the second reaction arm being hinged at one end to the base frame and at the other end to the bridge body; - a two-link rod mechanism, wherein first ends of the two links are hinged to each other, a second end of one link is hinged to the base frame, and a second end of the other link is hinged to the bridging body, the hinge axis of the rod mechanism being parallel to the width of the elongated contact surface; - a cam disposed on a shaft, the shaft being disposed adjacent to the rod mechanism, the shaft extending parallel to a hinge axis of the rod mechanism, the cam being in operative contact with the hinge axes of the first ends of the two links.

[0007] The actuation mechanism of the present invention uses two reaction arms to ensure that the bridge body moves in unison with the actuation rods of at least two contact points. A rod mechanism using only two links then translates the rotation of a cam on a shaft into the up and down movement of the bridge body, thereby opening and closing the contact points.

[0008] Therefore, the actuation mechanism of the present invention requires only four hinge links to reliably and simultaneously operate multiple contact points. Fewer links means fewer hinge points, which reduces the possibility of fluctuations in the operation of the actuation mechanism. This also reduces costs.

[0009] In a preferred embodiment of the actuation mechanism according to the invention, a cam follower is disposed on the hinge axis of the first ends of the two links, the cam follower being in contact with the cam.

[0010] The cam follower reduces friction between the cam and the hinge axis between the two links, resulting in smooth movement of the rod mechanism when the cammed shaft rotates.

[0011] A two degree of freedom hinge may also be used, but is preferred where the hinge axes of the first and second reaction arms are parallel to the width of the elongated contact surface.

[0012] The resulting hinge has one degree of freedom: rotation about the hinge axis.

[0013] In a further preferred embodiment of the actuation mechanism according to the invention, the bridge body comprises an elongated top wall and two side walls each depending from a longitudinal edge of the elongated top wall, and the elongated contact surface is formed by a surface of the top wall from which the side walls depend.

[0014] The top wall and two depending side walls form a profile with a U-shaped cross section, which is lightweight yet strong and low cost.

[0015] Preferably, the first reaction arm and the second reaction arm are disposed on opposite sides of the elongated top wall.

[0016] In a further preferred embodiment of the actuation mechanism according to the invention, a contact spring is provided at each of the at least two contact portions, the contact spring being arranged against the elongated contact surface and between the depending side walls, and the bridge body further comprises a locking plate arranged between the depending side walls, parallel to and spaced apart from the elongated top wall, whereby the contact springs are surrounded by the bridge body.

[0017] The contact spring ensures that the operating rod of the contact is forced into the open position. By using a locking plate to enclose the contact spring in the bridge body, the contact spring can be pretensioned, which affects the opening speed when the shaft and cam are released. [Brief explanation of the drawings]

[0018] These and other features of the present invention will be described in conjunction with the accompanying drawings. [Figure 1] 1 shows a perspective view of an actuation mechanism according to the prior art; [Figure 2] 1 shows a perspective view of an embodiment of an actuation mechanism according to the present invention; [Figure 3] 1 shows a schematic diagram of an actuation mechanism according to the present invention;

[0019] Figure 1 shows a prior art operating mechanism 1. The operating mechanism 1 is capable of operating three operating rods 2 of a vacuum circuit breaker 3. The operating mechanism 1 has a bridge body with a top wall 4 and two depending side walls 5 that enclose a contact spring 6.

[0020] The actuation mechanism 1 comprises four sets of two links 7, 8. The long links 7 are hinged at one end 9 to a frame (not shown) and at the other end 10 to short links 8 which are also hinged to the side walls 5 of the bridge body. The other ends 10 are also connected to each other via crossbars 11 between which are mounted cam followers 12 operated by cams 13 on shafts 14.

[0021] To maintain the combination of links 7, 8 and crossbar 11 in position, a reaction arm 15 is provided which is connected at one end 16 to the frame (not shown) and at the other end 17 to the bridge body.

[0022] Figure 2 shows an embodiment of an actuation mechanism 20 according to the invention. Parts corresponding to the embodiment of Figure 1 are designated with the same reference symbols.

[0023] The actuation mechanism 20 also has a bridge body with a top wall 4, depending side walls 5 (one of which is not shown for clarity), and a locking plate 21 for enclosing and pretensioning the contact spring 6 with the bridge body.

[0024] The first reaction arm 22 has one end 23 attached to the bridge body and the other end 24 hinged to a base frame (not shown).

[0025] The second reaction arm 25 is provided parallel to the first reaction arm 22, with one end 26 hinged to the bridge body and the other end 27 hinged to the base frame.

[0026] The first reaction arm 22 and the second reaction arm 25 ensure that the bridge body of the top wall 4 , the depending side wall 5 and the locking plate 21 move only in the direction of the operating rod 2 of the vacuum interrupter 3 .

[0027] The actuation mechanism 20 further comprises two rod mechanisms of rods 28, 29 which are hinged to each other at a centre 30, one end 31 of which is hinged to the depending side wall 5 and the other end 32 of which is hinged to the base frame.

[0028] The central hinge 30 is provided with a cam follower 33 which is in direct contact with a cam 13 disposed on the shaft 14 .

[0029] Figure 3 shows a schematic representation of the actuation mechanism 20 of Figure 2. From this schematic view, it can be seen that the first reaction arm 22 and the second reaction arm 25 are hinged at their ends 24, 27, respectively, to a base frame 34. Also, the other end 32 of the two rod mechanism of rods 28, 29 is hinged to the base frame 34 and to the shaft 24.

Claims

1. An actuation mechanism (20) for simultaneously opening and closing at least two contact portions (3), the actuation mechanism (20) comprising: - a base frame (34), - a bridge body (4, 5) having an elongated contact surface having a length and a width, said elongated contact surface configured to extend longitudinally over and contact the actuation rods (2) of said at least two contact portions (3); a first reaction arm (22) extending substantially parallel to the length of said elongated contact surface, said first reaction arm (22) being hinged at one end to said base frame (34) and at the other end to said bridge body (4, 5); a second reaction arm (25) extending parallel to the first reaction arm (22) at a distance of the first reaction arm (22) in a direction perpendicular to the elongated contact surface, the second reaction arm (25) being hinged at one end to the base frame (34) and at the other end to the bridge body (5, 6); a rod mechanism of two links (28, 29), the first ends (30) of which are hinged to each other, the second end (27) of one link (29) is hinged to the base frame (34) and the second end (32) of the other link (28) is hinged to the bridging body (4, 5), the hinge axis of the rod mechanism being parallel to the width of the elongated contact surface; an actuation mechanism (20) comprising a cam (13) arranged on a shaft (14), the shaft (14) being arranged adjacent to the rod mechanism (28, 29), the shaft (14) extending parallel to the hinge axes of the rod mechanism (28, 29), the cam (13) being in operative contact with the hinge axes of the first ends (30) of the two links (28, 29).

2. 2. The actuation mechanism (20) of claim 1, wherein a cam follower (33) is disposed on the hinge axis of the first ends (30) of the two links (28, 29) and is in contact with the cam (13).

3. 3. The actuation mechanism (20) of claim 1 or 2, wherein the hinge axes of the first and second reaction arms (22, 25) are parallel to the width of the elongated contact surface.

4. 4. An actuation mechanism (20) according to any one of claims 1 to 3, wherein the bridge body (4, 5) comprises an elongated top wall (4) and two side walls (5) depending respectively from longitudinal edges of the elongated top wall (4), and the elongated contact surface is formed by a surface of the top wall (4) from which the side walls (5) depend.

5. 5. The actuation mechanism (20) of claim 4, wherein the first reaction arm (22) and the second reaction arm (25) are arranged on opposite sides of the elongated top wall (4).

6. 6. An actuation mechanism (20) according to claim 4 or 5, wherein a contact spring (6) is provided at each of the at least two contact portions (3), the contact spring (6) being arranged against the elongated contact surface and between the depending side walls (5), and the bridge body (4, 5) further comprises a locking plate (21) arranged between the depending side walls (5) parallel to and spaced from the elongated top wall (4), whereby the contact spring (6) is surrounded by the bridge body.

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