DE10059600A1 - Cutting clamp with sprung cutting jaws for cutting through insulating cladding and making an electric connection with a wire - Google Patents

Abstract

The cutting clamp has sprung cutting jaws. The gap between the two jaws tapers towards the projection of the fork, although a return force can be increased by the penetrating, cut lead. The fork gap is almost parallel and the jaws press, due to spring forces, onto the metallic lead wire.

Description

State of the art

Insulation clips consist of a two-pronged metal fork, in their Gap an electrical, insulated conductor more or less perpendicular to it Longitudinal axis is plunged in, the insulation of the conductor so strong that the inner jaws of the fork hurt the metallic vein of the insulated conductor. There are insulation clamps for massive ones (single-wire) and for flexible (multi-wire) cores. You have to go to Cross-sectional size of the conductor to be clamped fit. insulation displacement terminals for solid conductor cores have been used for several decades Installation of telephone cables used. Insulation displacement clamps for flexible conductors veins have only emerged in the last decade.

Critique of the state of the art

While using insulation displacement clamps for solid conductor wires can be regarded as harmless both theoretically and practically , the insulation displacement clamp for flexible conductor cores must at least be theoretic be described as delicate.

The criterion for a professional electrical connection is its current carrying capacity ability or, in other words, their low contact resistance. at The contact pressure provides the required current carrying capacity for solderless connections ability sure. This contact pressure prevails for an insulation displacement clamp Solid conductor together from the restoring forces that occur when the Conductor both within the conductor wire and in the forks (cutting bake) of the insulation displacement clamp, because of the gap of the insulation clamp is slightly narrower than the diameter of the solid conductor Vein.

If the conductor and insulation piercing block fit together correctly, the predictable contact pressure achieved. This makes a reliable statement possible over the current carrying capacity, which in a quality assurance pro tokoll can be used without a review taking place got to.

The situation is different for insulation displacement terminals for flexible (multi-wire) Conductor cores. Because the tufts of wire adapt to the gap  can, by dodging the individual wires to the side, can be over the contact pressure does not make a clear statement. Not for nothing speaks the industry of "proven" insulation displacement technology, which is so much can be like: "Nothing has happened yet".

However, dimensional changes are to be expected, at least in theory against the multi-wire conductor wire due to temperature gradient and vibration. Because the insulation displacement contact fork is rigid and dimensional changes can not be compensated by resilience, the current carrying capacity ability to decrease over time. In a possible quality assurance protocol cannot make a clear statement about the contact resistance be made.

problem

Usual insulation displacement clamps for multi-wire conductors with rigid cutting Dimensional changes caused by temperature gradients can bake and vibration can occur, do not compensate for any resilience. Thereby there is no reliably stable transition wi in such a connection resistor. That cannot be the case in security-sensitive installations be taken.

Solution and achieved advantages

In an insulation displacement clamp according to the invention, the gap tapers in the fork, but can be expanded by the penetrating conductor. The restoring force (spring action) in at least one of the two Forks saved to accommodate any dimensional changes in the to be able to compensate for multi-wire conductors. The ver The material used must be able to perform this spring force storage. Depending on the requirements, there are several metal alloys of the type brass or bronze in question.

An expansion is possible if one or both cutting jaws are not rigidly connected to their origin, but by the conductor wire can be deflected laterally.

This can be achieved by having one or both forks on double the length and now half the length  be folded back so that the ends of the forks are inside (in near their origin). A conductor wire between two such constricting cutting jaws can be pressed in widen the narrowed gap as the folded back ends of the fork to the Side can be pushed. They store restoring force (spring force) over their entire length to the origin. This return positioning force immediately compensates for dimensional changes. you receives a contact pressure which, depending on the conductor cross section, is unique can be described. Another advantage is that actually different conductor cross sections due to the resilience - but within limits - be clamped in one and the same design can.

embodiment

A possible embodiment of the insulation displacement clamp according to the invention with resilient cutting jaws is shown in FIG. 1. It consists of a stampable sheet metal part ( 1 ) in which both prongs ( 2 ) of the cutting fork are folded back by 180 degrees. It can be seen that the fork gap ( 3 ) tapers.

In Fig. 2 you can see that an insulated conductor ( 4 ) has been pressed into the cutting fork. The insulation is partially severed, but - as with conventional insulation displacement terminals - this cannot be seen. However, it can be seen that the cutting jaws (forks) have been pushed aside by the conductor wire. The fork gap ( 3 a) is almost parallel and the cutting jaws press resiliently on the metallic conductor wire.

Claims (1)

Cutting clamp with resilient cutting jaws characterized in that the gap between the two cutting jaws tapers towards the origin of the fork, but the restoring force can be expanded by the penetrating, cut conductor.