DE19902931A1 - Clamp arrangement in explosion-protected form has clamps permanently integrated into insulating part, and connected via pressure-tight encapsulated microswitch actuated by eccentric lever - Google Patents

Abstract

The clamp arrangement has a clamp bolt and a clamp in an insulating part for each uninsulated cable end on the load side and on the supply side. Both clamps (2,3) are permanently integrated into the insulating part (1) and connected together via a pressure-tight encapsulated microswitch (4) actuated by an eccentrically mounted lever (7).

Description

The invention relates to a terminal arrangement for connecting electrical lines of non-intrinsically safe circuits in explosive atmosphere.

Such an arrangement is known from DE 195 13 645 C2. In the terminal arrangement is a movable, consumer-side Clamp and a fixed, feed-side clamp over one flameproof encapsulated microswitch in connection, the Microswitch by pulling out the consumer side Line is operated via the movable clamp.

This clamp arrangement has a complicated internal structure with lots of moving parts. There is a risk that the consumer side when operating the microswitch Line under tension loosens or breaks.

The object of the invention is a simply constructed terminals arrangement for connecting non - intrinsically safe circuits in to create an explosive atmosphere that extensive protection against incorrect operation when connecting and disconnecting the consumer-side line offers.

This object is achieved by a device with the features of Claim 1 solved.

There are two fixed clamps in the terminal arrangement attached via a microswitch in the type of protection Flameproof encapsulation are electrically connected. The parts Outside of the microswitch, the type of protection is increased Security built up. The switching plunger of the microswitch is operated via a rod by a rotatable lever that has an eccentrically round contour at the pivot point.

Is the lever on the feed side of the  Terminal arrangement folded, under which the infeed side Clamp is located, so is the opposite, consumer-side Clamp through the open microswitch without voltage and the consumer-side line can without sparking can be clamped safely. Then the lever on the Consumer side of the terminal arrangement folded, under which is the clamp on the consumer side, so over the eccentric rounding of the lever, the rod and the Switch plunger of microswitch to the closed position brought and both clamps are electrical with each other connected. This is the switch-on spark in the microswitch in the flameproof enclosure locked in. In this switch-on position of the folded This covers the clamping screw of the lever consumer clamp, so that accidental loosening of the consumer line is excluded. Furthermore, through different labeling with color, symbols and / or labeling of the two visible lever surfaces in the Switch on and off position even more security against Incorrect operation can be achieved.

For safe disconnection of the consumer line the lever again on the feed side of the Terminal arrangement folded.

The terminal arrangement according to the invention is at a minimum Moving parts easy and space-saving to build, with a Maximum level against incorrect operation is achieved.

An embodiment of the invention is in the figures shown and is described in more detail below. Show it:  

Fig. 1-sectional view of the clamp assembly along the section line AA in the ON state of Fig. 3

FIG. 2 shows a sectional illustration of the terminal arrangement in the switched-off state along the section line AA from FIG. 3

Fig. 3 top view of the terminal arrangement in the switched on state

The insulator ( 1 ) contains the feed-side clamp ( 2 ), the consumer-side clamp ( 3 ) and the flameproof microswitch ( 4 ), which electrically connects the two clamps ( 2 , 3 ). On the underside, the insulating body ( 1 ) is provided with a snap device ( 5 ), as a result of which several terminal arrangements can be installed on a (not shown) mounting rail in a (not shown) housing in the type of protection increased safety. When setting up the terminal arrangement in the potentially explosive area, the supply-side line is originally connected without voltage and then switched on by a switch (not shown) in the safe area.

Then the lever ( 7 ) is folded onto the feed side of the terminal arrangement. Since the lever ( 7 ) is rotatably mounted on an axis ( 8 ) and has an eccentrically round contour about this axis ( 8 ), the rod ( 9 ) and the plunger of the microswitch ( 4 ) are in the upper position in this position, so that the microswitch ( 4 ) is open. Here, the consumer-side clamp ( 3 ) is voltage-free, so that the consumer-side line ( 10 ) can be safely connected. Now the lever ( 7 ) is folded in an abutting manner on the consumer side of the terminal arrangement, as a result of which the plunger of the microswitch ( 4 ) is pressed in via the eccentric contour, the rod ( 9 ) and the microswitch ( 4 ) is brought into the closed position. The switch-on spark is thus generated safely in the flameproof enclosure of the microswitch ( 4 ). In this switch-on position, the clamping screw of the clamp ( 3 ) on the consumer side is covered by the lever ( 7 ). This effectively prevents the unintentional and dangerous disconnection of the consumer-side line ( 10 ) under voltage.

To disconnect the consumer-side line ( 10 ), the lever ( 7 ) is folded in abutment against the feed-side side of the terminal arrangement, whereby the eccentric contour of the lever ( 7 ), the rod ( 9 ), the switching plunger of the microswitch ( 4 ) in the upper position arrives so that the microswitch ( 4 ) opens electrically. The switch-off spark is securely encapsulated in the interior of the microswitch ( 4 ).

Now the clamping screw of the consumer-side clamp ( 3 ) is free and the consumer-side line ( 10 ) can be safely disconnected without tension.

In order to securely fix the two positions of the lever ( 7 ), the eccentric contour of the lever is provided with corresponding notches ( 11 ).

In order to avoid confusion when connecting and disconnecting the consumer-side line ( 10 ), the surfaces of the lever ( 7 ) visible upwards are marked accordingly with color, symbols and / or lettering.

In terms of explosion protection according to z. B. EN 50 014 ff Microswitch in flameproof enclosure, while the rest of the Terminal is built in increased security. A possible Labeling would then be e.g. B. EEx de IIC T6.  

Reference list

1

Insulating body

2nd

feed-side clamp

3rd

consumer clamp

4th

Microswitch

5

Snap device

6

feed-side line

7

lever

8th

axis

9

pole

10th

consumer line

11

Notches

Claims (2)

1. Terminal arrangement for connecting electrical lines of non-intrinsically safe circuits in an explosive atmosphere, wherein a clamping screw and a clamp are seen in front of each consumer side and each insulation-free line end that can be connected on the supply side, characterized in that

• - That both clamps ( 2 , 3 ) are firmly installed in the insulating body ( 1 ) and are connected to one another via a pressure-tight encapsulated microswitch ( 4 ).
• - That an eccentrically mounted lever ( 7 ) actuates the micro switch.

2. Terminal arrangement according to claim 1, characterized in

• - That the lever ( 7 ) covers the clamping screw of the consumer-side clamp ( 3 ) in the switched-on state.
• - That the lever ( 7 ) has notches ( 11 ) for fixing the switch-on and switch-off positions.
• - That the lever ( 7 ) on its visible in the on and off condition surfaces markings and warnings in color, symbols and or Be inscription text.