CN102214530A - Switch, particularly power switch - Google Patents

Abstract

The invention relates to a switch, in particular a power switch, having a housing in which a rotor is rotatably supported; deflected between the open position and has at its free end a contact piece that moves with the contact arm, which when the switch is closed when the contact arm is in its on position rests against the opposite fixedly arranged contact piece, wherein when a) the current flowing through the contacts exceeds a predetermined value and b) the rotor rotates, the contact arms are deflected and the mutually abutting contacts are separated from each other, wherein the rotor brings the contact arms together into their open position middle. In order to ensure the function of the switch, it is proposed to arrange a blocking element at least on one side of the contact arm, which engages in a recess in the housing at the latest when the OFF position is reached, thereby preventing the contact arm from turning back ON in position.

Description

switches, especially power switches

technical field

The invention relates to a switch, in particular a power switch, according to the preamble of claim 1 .

Background technique

Power switches are well known and are used to interrupt the current flow in the event of a short circuit. For this purpose, the power switch has a contact arm which can be pivoted between an on position and an off position. The contact arm carries a contact piece at its end, which bears against the opposite contact piece when the switch is closed. The current to be interrupted flows via the switch from the grid-side terminal to the load-side terminal via the two contact pieces and the contact arm. In the event of a short circuit, the contact arms are deflected by the magnetic force generated by the occurring short circuit current, whereby the two contact pieces are separated from each other. The contact arms are mounted rotatably in the rotor; rotation of the rotor likewise leads to a deflection of the contact arms and separation of the contact pieces.

In a multi-pole switch, the contact arms of the individual phases are located in the respective pole box, and the rotors of pole boxes arranged next to each other are connected in a non-rotatable manner to form a switching shaft, the switching shaft extending transversely to the pole box. Rotation of the switching shaft simultaneously deflects all contact arms into their off or on position, depending on the direction of rotation. The switching shaft is pretensioned by a spring and engages in the ON position. In the event of a short circuit, the associated contact arm is deflected magnetically into its open position and first interrupts the current flow in this phase. The engagement is then released and the switching shaft interrupts the current in the remaining phases.

The disadvantage here is that the contact arm of the phase in which the short-circuit current occurs sometimes springs back into its on position after being deflected upwards into the off position, which can cause damage to the switch itself and even damage to subsequent loads .

Contents of the invention

The task of the invention is to ensure the protective function of the switch.

This object is achieved by the features of claim 1 ; the subclaims are advantageous refinements.

This solution provides that at least on one side of the contact arm a blocking element is arranged, which engages in a recess in the housing at the latest when the off position is reached, so that the contact arm is prevented from being swiveled back into the on position. . That is to say that the blocking element is positioned in the housing to a certain extent and in this way prevents the contact arm from falling back into the switched-on position.

It is more effective if the blocking elements are respectively arranged on both sides of the contact arm.

A technically simple embodiment provides that the locking element is designed as a spring element, in particular as a leaf spring.

A low-wear embodiment provides that a spring element is held in the rotor under tension, which leaves the rotor when the contact arm is deflected and before it moves into the housing recess before reaching the disconnected position, in particular in the form of a web. slide along the housing protrusion.

It is advantageous if the spring element is tensioned cooperating with the rotor when the switch is switched on and moves back together with the rotor in the tensioned state.

Description of drawings

The present invention will be described in detail below based on the examples. The accompanying drawings show:

Figure 1 is the pole box of the switch with the half-shells removed,

Fig. 2 is the switch arm configured as a double-arm lever according to Fig. 1,

Fig. 3 is the cross-section seen from above according to the pole box of Fig. 1,

Fig. 4 is the rotor of the switch according to Fig. 1 together with the contact arm, and

FIG. 5 shows the pole box according to FIG. 1 with the rotor and the contact arms with the half shells removed.

Detailed ways

FIG. 1 shows a pole box 1 of a multipole power switch, referred to below as a switch. The pole box 1 forms the housing 1 a and consists of two half-shells 2 , one of which is removed in FIG. 1 . The pole box 1 has two connection terminals 3 , on the inner ends of which a fixed contact piece 4 is arranged in each case. On the contact piece 4 rests an associated contact piece 5 which is arranged at the free end of a contact arm 6 which is designed here as a double-armed lever. In addition, a rotor 7 in the form of a switching shaft section is rotatably mounted in the pole box 1 , in which rotor the contact arm 6 is in turn mounted in a pivotable manner. The two axes of rotation coincide here. The contact arm 6 is pivotable between an on position and an off position; in FIG. 1 the contact arm 6 is in its on position, in which the switch is switched on. When the switch is connected, current flows from the line-side terminal 3 via the two contact pieces 4 , 5 , the contact arm 6 and the two further contact pieces 5 , 4 to the load-side terminal 2 . When the switch is opened, an arc is generated between the contacts 4 , 5 , especially in the event of a short circuit, which is quickly extinguished by means of a quenching plate inserted into the socket 8 .

FIG. 2 shows a contact arm 6 with a locking element 10 in the form of a spring element 10 a which is fixed on both sides of the contact arm 6 . The spring element 10 a here is in particular a leaf spring.

In FIG. 3 only the contact arm 6 with the two spring elements 10a and the rotor 7 can be seen, wherein the spring elements 10a (by the rotor 7) are held tensioned inside the rotor 7 by virtue of the fact that the ends of the spring elements are held by The contact edge 11 of the rotor 7 remains compressed.

FIG. 4 shows the rotor 7 with the contact arms 6 inserted in the half shell 2 of the pole box 1 . The contact edge 11 can be seen particularly well in FIG. 4 , which—with reference to FIG. 4 —has a bevel 12 in the upper region. 3 and 4 show the switch in the on state and thus the contact arm 6 in the on position, in which the contact piece 5 of the contact arm abuts without On the fixed contact piece 4 shown.

In the event of a short circuit, the current flowing through the contacts 4, 5 correspondingly exceeds a predetermined threshold value for a very short time, which is associated with a large magnetic repulsion force acting on the contact arm 6, said repulsion force at When the rotor 7 is fixed, the contact arms 6 are deflected upwards when the contacts 4 , 5 are separated. Subsequently, the contact arm 6 is in its open position.

FIG. 5 shows the pole shoe 1 in section with the contact arm 6 in the disconnected position. It can be seen that the end of the spring element 10 a , which can be seen in FIG. 5 , lies in the housing recess 13 . The housing recess 13 is formed by a housing projection 14 in the form of a web 14 a and an inner surface 15 . When short-circuiting causes deflection of the contact arm 6, the spring element 10a moves from the fixed rotor 7 to the It slides on and along the outer edge 16 . This prevents the contact arm 6 from swiveling back or springing back into its switched-on position.

If the rotor 7 moves in the clockwise direction, it brings the contact arm 6 together into its open position, more precisely by means of the abutment element 17 against which the contact arm 6 rests. on the components.

Conversely, when the rotor 7 is rotated in the counterclockwise direction, the contact arm 6 is turned into its switch-on position. Here again, the contact arm 6 is held by the rotor 7 , wherein the end of the spring element 10 a is compressed by the ramp 12 and moved into the socket of the rotor 7 .

In the case of a multi-pole switch, the rotor 7 is joined as a switch shaft. The deflection of the contact arm 6 caused by the short circuit activates the trigger, which then triggers an upward deflection of all remaining contact arms 6 , wherein the engagement of the switching shaft is released.

To switch on the switch, the switch shaft is turned counterclockwise, wherein each rotor 7 accommodates a spring element 10 a by means of a ramp 12 and moves together with the contact arm 6 into the on position. Then engage the swivel switch shaft again.

Claims (5)

1. Switches, especially power switches, has a housing (1a) in which a rotor (7) is rotatably supported, There is a contact arm (6) rotatably supported in said rotor (7), which can be deflected between an on position and an off position and has a contact arm (6) at its free end a moving contact piece (5), which bears against the opposite, fixedly arranged contact piece (4) when the switch is closed when the contact arm (6) is in its switched-on position, The contact arms ( 6 ) are deflected and contact each other when a) the current flowing through the contact pieces ( 4 , 5 ) exceeds a predetermined value and b) the rotor ( 7 ) rotates parts (4, 5) are separated from each other, wherein the rotor brings the contact arm (6) together into its disconnected position, It is characterized in that, Arranged on at least one side of the contact arm (6) is a blocking element (10), which engages in a housing recess (13) at the latest when the disconnected position is reached. 2. The switch according to claim 1, It is characterized in that, Locking elements (10) are respectively arranged on both sides of the contact arm (6). 3. The switch according to claim 1 or 2, It is characterized in that, The locking element ( 10 ) is designed as a spring element ( 10 a ), in particular as a leaf spring. 4. The switch according to claim 3, It is characterized in that, The spring element (10a) is held tensioned in the rotor (7), which spring element leaves the rotor (7) when the contact arm (6) is deflected and moves into the housing recess Before unloading at ( 13 ), it slides along a housing projection ( 14 ), in particular in the form of a tab ( 14 a ), before reaching the disconnected position. 5. A switch according to claim 3 or 4, It is characterized in that, The spring element ( 10 a ) is tensioned cooperating with the rotor ( 7 ) and moves back together with the rotor ( 7 ) when the switch is switched on.

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