DE20112090U1 - Clamping element with a sleeve body for stripping-free connection of an electrical conductor - Google Patents

Description

The invention relates to a clamping element with a sleeve body having a longitudinal clamping slot for connecting an electrical conductor without stripping the insulation. The sleeve body has two spring legs that converge towards the clamping slot and have cutting edges that are arranged parallel to one another on the clamping slot. In the clamping position, these define a clamping plane between them that passes through the clamping slot and in which the conductor end to be contacted is inserted between the cutting edges transversely to its longitudinal axis in the direction of the clamping slot. For this purpose, the cutting edges merge into diverging run-in slopes at the insertion end of the clamping slot.

Such a clamping element is known from DE 199 09 825 Al. In this version, the sleeve body is covered

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designed mirror-symmetrically to the clamping plane passing through the clamping slot, whereby the two cutting edges at the ends of the spring legs are opposite each other at the same height at the clamping slot. When the clamping legs of the sleeve body are bent towards each other in a roof shape, a small gap remains between the cutting edges in the finished state, i.e. in the non-clamping position, and accordingly the two cutting edges do not reach completely to the clamping plane. The resulting gap across the clamping plane has a disadvantageous effect if the metal core of a conductor is to be contacted, the diameter of which, including the insulating jacket, is at the lower limit of the conductors that can be contacted in the clamping element of the relevant dimension. With such relatively thin, stranded conductors, there is a risk that the conductor insulation will hardly be penetrated when the conductor is pushed into the clamping slot of the sleeve body and, due to the distance between the cutting edges on the spring legs, there will not be sufficient electrical contact pressure on the metal core of the conductor.

The invention is therefore based on the object of creating a clamping element of the generic type, in which a secure contact is also provided for conductors that are relatively thin.

This object is achieved in a clamping element of the generic type according to the invention by the characterizing features of patent claim 1.

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It is essential for the invention that the gap width of the clamping slot is zero in the vertical direction between the cutting edges, i.e. viewed in the direction of the clamping plane, or that a scissor-like overlap of the two cutting edges can even be provided at the clamping slot. As a result, when the conductor to be clamped is pushed into the clamping slot of the sleeve body, the spring legs expand and the conductor insulation is safely severed down to the metal core, thus achieving perfect contact, for which sufficient contact pressure is important in order to avoid a higher transition resistance.

It is advisable to choose the offset of the cutting edges at the ends of the clamping legs in the vertical direction of the clamping plane so that only a negligible leverage effect is exerted on the conductor, so that the conductor does not bend when its insulating sheath is severed and the counter-bearing important for cutting the insulating sheath is not lost. Otherwise, the insulated conductor could move transversely to its direction of displacement and the necessary pressure to displace the conductor insulation material would then be lacking at the relevant cutting edge.

The invention is explained in more detail below with reference to an embodiment example and the drawing.

Fig. 1 a perspective view of the sleeve body
an electrical clamping element,

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Fig. 2 the front view of a complete clamping system
and

Fig. 3 a slightly perspective side view of the

Clamping element according to Fig. 2 in the position before
Inserting the conductor to be clamped into the
Clamping slot of the sleeve body.

The sleeve body 1 shown in Fig. 1 consists of a one-piece bent sheet metal part, which is manufactured as a stamped part preferably from steel, brass or copper. A base part 10, which has the largest cross-section, is followed by spring legs 2 in the manner of U-flanges, which merge into angled end sections 3, which are bent towards one another in the manner of roof slopes. The end edges of the end sections 3 of the spring legs 2 facing the base part 10 form cutting edges 4, which delimit a clamping slot 5. Up to this clamping slot 5, the cross-section of the spring legs 2 and their end sections 3 tapers continuously, resulting in optimal stress distribution when the spring legs 2 are deflected away from the clamping slot 5.

Figures 2 and 3 illustrate the insertion of the end 8 of a conductor 6 to be clamped into the clamping slot 5 of the sleeve body 1 and the position of the conductor end 8 in the clamped end position. To hold the conductor end 8, the clamping element has a guide body 7 which is oriented in the direction of the arrow B shown in Fig. 3 relative to the sleeve.

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body 1 is moved, with a lower part 11 of the guide body 7 dipping into the interior of the sleeve body 1, while an upper part 12 of the guide body 7 is moved above the clamping slot 5 of the sleeve body 1. The conductor end 8 to be clamped is held exposed between the lower part 11 and the upper part 12 of the guide body 7. The conductor 6 has a metal core 3 to be contacted by the cutting edges 4 of the sleeve body 1, which is surrounded by an insulating jacket 14, which generally consists of a plastic material that can be severed by the cutting edges 4 of the sleeve body 1. So that the conductor end 8 finds its way safely into the clamping slot 5 of the sleeve body 1 when the guide body 7 is moved in the direction of arrow B towards the sleeve body 1, the cutting edges 4 of the sleeve body 1 merge into run-in slopes 9 on the insertion side of the clamping slot 5.

This is particularly important because in the non-clamping starting position, the cutting edges 4 of the sleeve body 1 lie in a common plane that is perpendicular to the base part 10 of the sleeve body 1 and extends in the longitudinal direction of the clamping slot 5. This plane, referred to as the clamping plane E, is the plane in which the axis A of the conductor end 8 to be clamped is displaced during the clamping process when it enters the clamping slot 5. In the vertical projection towards the base part 10 of the sleeve body 1, the clamping slot 5 thus has a gap width of zero as far as the position of the cutting edges 4 of the sleeve body 1 in the unclamped position is concerned, in which the spring legs 2 of the sleeve

♦ ·

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sen body 1 are not deflected away from each other. In the initial position of the spring legs 2 of the sleeve body 1, the cutting edges 4 at the spring leg ends 3 can not only lie together in the clamping plane E, they can also extend slightly beyond it, which results in an overlap of the spring leg ends 3 in the area of the cutting edges 4 in the vertical projection towards the base part 10 of the sleeve body 1.

In the clamped end position, which is not shown in the drawing, the spring legs 2 are expanded by a spring travel corresponding to the diameter of the metal core 13 of the conductor 6, which ensures a secure contact pressure of the cutting edges 4 on the metal core 13 of the conductor 6 and which ensures a reliable cutting through of the insulating jacket 14 of the conductor 6 up to its metal core 13 when moving within the clamping slot 5 to the end position.

To ensure that the spring leg ends 3 do not collide with their cutting edges 4 in the unclamped position, they are slightly offset from one another in the vertical direction of the clamping plane E. The offset is selected to be as minimal as possible so that the leverage effect on the conductor end 8 is kept as low as possible in order to avoid any disturbing deflection of thin and slightly flexible conductors 6 in the direction away from the clamping plane during the clamping process. In this way, even the conductor 6 that has the smallest diameter for the given size of the sleeve body 1 can be securely contacted.

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diameter of the conductor to be clamped. The offset of the cutting edges 4 of the spring leg ends 3 can be achieved both by unequal lengths of the angled spring leg ends 3 and by their different roof slope angles.

Claims (3)

1. Clamping element with a sleeve body ( 1 ) having a longitudinal clamping slot ( 5 ) for the connection of an electrical conductor ( 6 ) without stripping the insulation, the sleeve body ( 1 ) having two spring legs ( 2 ) converging towards the clamping slot ( 5 ) with cutting edges ( 4 ) arranged parallel to one another on the clamping slot ( 5 ), which in the clamping position define between them a clamping plane (E) passing through the clamping slot ( 5 ), in which the conductor end ( 8 ) to be contacted is inserted between the cutting edges ( 4 ) transversely to its longitudinal axis (A) in the direction of the clamping slot ( 5 ), for which purpose the cutting edges ( 4 ) merge into diverging inlet strokes ( 9 ) at the insertion end of the clamping slot ( 5 ), characterized in that the cutting edges ( 4 ) in the non-clamping position with the spring legs ( 2 ) not deflected accordingly extend at least to the clamping plane (E) and are arranged offset from one another in this plane. 2. Clamping element according to claim 1, characterized in that the cutting edges ( 4 ) in the non-clamping position each extend beyond the clamping plane (E) opposite to the direction of deflection in the clamping position. 3. Clamping element according to claim 1 or 2, characterized in that the offset of the cutting edges ( 4 ) in the clamping plane (E) is so small that the conductor to be clamped ( 6 ) with the lowest bending resistance in the clamping position with the clamped conductor end ( 8 ) is not bent out of the clamping plane (E) or is bent out only to a negligible extent.