CN104425908B - switch - Google Patents

Abstract

The invention relates to a switch with: an electrically insulating pole housing (1); a switch contact, the contact elements of which contact each other when the switch is closed; a clamping unit in the form of a frame (3a) (3), the clamping unit (3) is connected to the fixed contact element and has a frame opening (3b), in which the first channel in the wall of the pole housing (1) can be passed from the outside opening (5) for inserting the connecting cable; clamping screw (6), which extends transversely to the insertion direction (4) into the frame opening (3b) and can be clamped to the frame (3a) by means of the connecting cable and a second opening (8) in the wall of the pole housing (1) through which a tool can be inserted. In order to meet the specified air travel and creepage travel also in the case of large cable diameters, it is recommended that the second opening (8) be displaceable transversely to the clamping screw (6) engaging in the lateral guide groove (9) The closing element (7) is closed.

Description

switch

technical field

The invention relates to a switch with an electrically insulating pole housing; a switch contact, the contact elements of which rest against each other when the switch is closed; a clamping unit in the form of a frame, the clamp The clamping unit is connected to the fixed contact element and has a frame opening into which the connecting cable can be inserted from the outside through a first opening in the wall of the pole housing; a clamping screw transverse to the insertion a direction extending into the frame opening and being clampably fixed in the frame by means of a connecting cable; and a second opening in the wall of the pole housing through which a tool can be inserted.

Background technique

Switches in the form of load disconnect switches are known. In a multi-pole configuration, the switch has an electrically insulating pole housing per pole, in which are arranged switching contacts whose contact elements in the form of contact blocks interact with each other when the switch is closed. Abutment, in which each movable contact piece presses against a fixed contact piece. Typically, the contact piece is arranged on a double-armed lever pivotable about an axis of rotation. A common switching axis runs transversely through the pole housing so that all switching contacts can be opened and closed simultaneously. For connecting connecting cables, clamping units are often used which are frame-shaped and are connected to fixed contact blocks. The frame has a frame opening into which a connecting cable can be inserted. For this purpose, corresponding openings are provided in the wall of the pole housing. A clamping screw runs transversely to the insertion direction, said clamping screw extending into the frame opening. By turning the clamping screw with the aid of a screwdriver, the connecting cable can be clamped in place in the frame. For this purpose, a screwdriver is inserted through the opening in the wall of the pole housing.

Due to the limited installation space, the use of frame clamps with large cable diameters leads to the problem that the specified air travel and creepage travel (Kriechstrecke) are not met.

Contents of the invention

The technical problem to be solved by the present invention is to overcome this shortcoming.

The solution is provided by the fact that the (second) opening can be closed by a closing element which can be moved transversely to the clamping screw and which engages here in a guide groove running laterally in the direction of movement .

The closure is ensured in a simple manner if the closure element can be acted upon with a spring force in the closing direction.

In a technically simple embodiment, the elastic force is formed by a spring.

Expediently, the spring is fastened at one end to the closure element.

A particularly simple construction of the spring is that the spring has a meander shape.

In the simplest case, the meander-shaped spring and closing element are formed from a single plastic part.

Description of drawings

This aspect is described in detail below according to the embodiment, and each figure is:

Figure 1 shows a partial sectional view of the pole housing of a load disconnector with the closure element in its closed position, and

FIG. 2 shows the pole housing according to FIG. 1 with the closure element in the open position.

detailed description

FIG. 1 shows a pole housing 1 of a load disconnector, which is hereinafter referred to simply as a switch. The pole housing 1 is formed from an electrically insulating material and is formed from two plastic half-shells 1a, 1b. Inside the housing there are two switching contacts whose contact elements in the form of contact blocks bear against each other when the switch is closed. The two contact pieces are arranged fixedly and the two contact pieces are arranged movably. The movable contact piece is located at the free end of the double-armed lever which is pivotable about an axis of rotation which coincides with the axis of rotation of the switch shaft 2 . Rotation of the switching shaft 2 causes the movable contact piece to rest against or separate from the fixed contact piece, depending on the direction of rotation (all parts except the pole housing 1 and the switching shaft piece 2a of the switching shaft 2 are not shown ).

Each multipole switch comprises a plurality of such pole boxes 1 , which lie against each other with their large-area sides, wherein the switching shaft pieces 2 a of the switching shaft 2 are coupled together such that a continuous switching shaft 2 is formed.

Clamping units 3 each having a frame 3 a are used for connecting connecting cables, not shown. In the direction of the arrow 4, one end each of the connecting cables can be inserted into the frame opening 3b. The insertion takes place in each case through a (first) opening 5 present in the pole housing 1 (see right in FIG. 1 ). The clamping screw 6 runs transversely to the insertion direction 4 , of which only the screw head 6 a is visible in FIG. 1 . The clamping screw 6 projects with its shank into the frame opening 3b.

A closure element 7 in the form of a plastic cover is located above the screw head 6 a in FIG. 1 and closes off the (second) opening 8 , as can be seen on the right side of the pole housing 1 , which is not broken. The closure element 7 is in its closed position. The closure element 7 is guided longitudinally displaceably in a lateral guide groove 9 parallel to the arrow direction 4 , which is schematically illustrated by a double arrow 10 . Attached to the closure element 7 is a meander-shaped spring 11 , which is shown in the released state in FIG. 1 . The closure element 7 and the spring 11 are here formed from a one-piece plastic part. Connecting rails 3c connect the frames 3a respectively to the fixed contact blocks (covered by the front plastic half-shell 1a).

FIG. 2 shows the pole housing 1 according to FIG. 1 with an open closure element 7 which has been shifted to the right relative to FIG. 1 (for example, with a screwdriver slightly before being inserted into the opening 8 ). . The meander-shaped spring 11 is compressed and thus tensioned. Through the recess 12 formed on the closure element 7, a screwdriver can easily be introduced and clamped the inserted connecting cable. If the screwdriver is removed from the opening 8 and the recess 12 , the spring 11 automatically moves the closing element 7 again to the left and thus closes the opening 8 .

Claims (6)

1. A switch with electrically insulating pole housing (1), switching contacts, the contact elements of which rest against each other when the switch is closed, Clamping unit (3) in the form of a frame (3a), which is connected to the fixed contact element and has a frame opening (3b) in which the The first port (5) in the wall of the pole housing (1) is inserted into the connecting cable, a clamping screw (6), which extends transversely to the insertion direction (4) into the frame opening (3b) and is fastened in a clampable manner in the frame (3a) by means of a connecting cable, and a second opening (8) in the wall of the pole housing (1), through which a tool can be inserted, It is characterized in that, The second opening (8) can be closed by a closing element (7) which engages in the lateral guide groove (9) and is movable transversely to the clamping screw (6). 2. Switch according to claim 1, characterized in that the closure element (7) is exerted with a spring force in the closing direction. 3. Switch according to claim 2, characterized in that the elastic force is formed by a spring (11). 4. Switch according to claim 3, characterized in that the spring (11) is fastened with one end to the closing element (7). 5. Switch according to claim 4, characterized in that the spring (11) has a meander shape. 6. Switch according to claim 5, characterized in that the spring (11) and the closing element (7) are formed from one plastic part.