CZ282282B6 - Self-cutting locking contact - Google Patents

Abstract

An insulation displacement contact element (1) for connecting electric conductors without stripping them is punched out of a substantially flat electroconducting metallic material with at least one substantially slot-shaped incision (3) which separates two contact legs (2a, 2b) that lie substantially in a common plane and are integrally interconnected at one of their ends. Substantially parallel, mutually opposite contact surfaces (3a, 3b) are designed at the contact legs along at least one partial area of each incision, the contact surfaces (3a, 3b) being inclined with respect to the plane of the contact legs. Alternative embodiments of the insulation displacement contact element have a contact slot with a reduced width of up to 0 mm, and if required the contact legs are pre-stressed.

Description

(57)

Self-tapping terminal contact (1) for connecting electrical conductors without stripping, cut from one plate of electrically conductive metal material, with at least one contact slot (3) separated by two contact legs (2a, 2b). The contact arms (2a, 2b) lie in one common plane and are integrally connected at one end thereof. At least along a partial portion of each notch, contact surfaces (3a, 3b) extending parallel to one another are formed on the contact arms (2a, 2b). The contact surfaces (3a, 3b) extend obliquely to the plane of the contact arms (2a, 2b). The variants of the self-tapping clamp contact have a reduced contact slot width (d) of up to 0 mm, whereby biasing is optionally provided on the contact arms (2a, 2b).

Self-drilling terminal contact

Technical field

The invention relates to a self-tapping terminal contact for connecting electrical wires without stripping.

BACKGROUND OF THE INVENTION

Such a self-tapping clamp contact is known from EP-A-0 459 144.

Such self-tapping terminal contacts are used in particular in communication and data transmission techniques. When the insulated electrical conductor is pushed into the contact slot of the self-tapping terminal contact, the insulation is cut and conductive contact is established between the conductor and the self-tapping terminal contact.

Another self-tapping clamp contact, known from WO 91/08599, has chamfered chamfers at the longitudinal edges of the contact arms which define the contact slot, which are interrupted by the non-bevelled intermediate region. In this case, the contact arms are separated from each other by cutting and pivoting, and the chamfers are formed before the contact arms are cut. In this case, the contact surfaces, which are not punched, run obliquely through the bushes of the contact arms of the respective contact arm.

Furthermore, a self-tapping clamp contact is known which has two flat contact arms which lie in one common plane and which are separated by a contact slot whose contact surfaces extend perpendicular to this common plane. This self-tapping clamp contact is generally arranged in its housing such that it is tilted about 45 degrees about its longitudinal axis and the electrical conductor to be contacted is inserted into its contact slot with its longitudinal axis of the veins at an angle of 45 degrees relative to the plane of the contact arm. As schematically illustrated in FIG. 8, in the known self-tapping clamp contact dochází, there is a shear load on the connected conductor 12, which leads to cutting of the conductor and thus to the risk of shearing, especially with thin wires or cables.

DE 41 26 068 C1 discloses a self-tapping clamp contact in which the two contact arms are separated from one another along the contact slot by shearing, and in which the contact arms transverse to the plane of the contact arms are offset by the thickness of the contact arms relative to each other. has a contact slit width in the range of 0 mm to 0.05 mm. In the second variant disclosed herein, the contact arms are rotated relative to each other after separation. These self-cutting terminal contacts are preferably arranged obliquely so that the self-cutting terminal contact forms an angle with the longitudinal axis of the connected conductor, for example in the range of 30 to 60 degrees. Also with this conventional self-tapping clamp contact, the problem described above occurs that the contact edges of the contact slot stress the attached conductor to shear and cause a notch effect.

The problem of shear stress and chopping of the connected conductor occurs in another known self-tapping clamp contact in which two contact arms are pivoted from the plane of the contact arm by about 15 degrees to reduce the width of the contact slot.

It is therefore an object of the present invention to provide a self-tapping clamp contact in which the connected conductor is not subjected to shear and does not cut the conductor.

SUMMARY OF THE INVENTION

This object is achieved by the self-tapping clamp contact according to the invention, the principle being that the contact surfaces are die-cut from metallic material and run at an angle in the range of 35 degrees to 80 degrees with respect to the plane of the contact arms.

By the inclined arrangement of the contact surfaces, the self-tapping clamping contact between the connected conductor and the contact arms leads to surface contact. By contacting the conductor with the contact surfaces, and the sharp edges between the contact surfaces and the bounding surfaces of the contact arms do not cut into the conductor, there is no chopping and there is no danger of cutting particularly thin connected conductors. The connected conductor causes torsional stress in the contact arms and is thus securely held by the surpassed contact arms.

The contact surfaces form an angle with the plane of the contact arms, in particular in the range from 35 to 85 degrees. Especially preferred is an embodiment in which the contact surfaces form an angle of 45 degrees with the plane of the contact arms. In the 45 degree orientation of the contact surface skew with respect to the contact arm plane, the self-tapping clamp contact may be arranged perpendicular to the longitudinal axis of the conductor to be connected.

The self-tapping clamp contact according to the invention can be made with a single tool, since no further shaping or bending processes follow the production of the notch with the inclined contact surfaces. {The contact surfaces are die-cut from a metallic, electrically conductive material from which a self-tapping clamp contact is made.}

While only the width of the contact slot, i.e. the spacing between the parallel contact surfaces, above about 0.6 times the thickness of the contact arm material is feasible, another embodiment is contemplated in which the width of the contact slot is reduced beyond the possible compression technique. In this preferred embodiment, two adjacent contact arms are transversely displaced in the transverse direction to the notched edge within the plane of the contact arms, in order to reduce the distance between two adjacent contact surfaces. This additional displacement of the two adjacent contact surfaces by plastically shaping the respective contact arms can reduce the width of the contact slots up to a width of 0 mm. Since the material thickness of the plate, electrically conductive metal material from which the self-tapping clamp contacts are made is usually in the range of 0.5 mm. the contact slot feasible width of the contact slot is approximately 0.3 mm. Thus, with conventional self-tapping terminal contacts of this kind in which only the contact slot is punched but no further shaping of the contact arms has been made, safe contacting of thin wires and cables is problematic because the at least achievable contact slot width for securely holding the electrical conductor in the slot sufficient. On the other hand, in the embodiment described above, the width of the contact slot can be adapted optimally to the thickness of the conductor to be connected. In this case, even for very thin wires, flat contacting is achieved without shearing.

Since in the case of very thin wires, sufficient torsion is not often provided in the contact arms to ensure the contact durability, a further preferred embodiment of the self-tapping clamping contact according to the invention is provided, with additional biasing. by means of which even very thin connected conductors are securely held between the contact surfaces, fed to contact arms belonging to each other. In this embodiment, the width of the contact slot is reduced to 0 mm in the manner described above, but additionally a bias is created, i.e. a force which additionally presses the contact surfaces lying together. This preload occurs after a short-term displacement of the superposed contact surfaces opposite one another and across the plane of the contact arms. Therefore, even very thin connected conductors are securely contacted by the prestressing force, although these cannot, due to their small diameter, create torsional stresses in the contact arms.

-2GB 282282 B6

In the above-described embodiments, it is preferred that the contact surfaces of the two adjacent notches run in the opposite direction of each other in their orientation in the case of a plurality of notches for simultaneously contacting multiple electrical conductors. In other words, the contact surfaces set in an oblique fashion in succession in the same direction and in the opposite direction follow one another in a row of side-by-side notches, the contact surfaces naturally extending substantially parallel to each other within the notch.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the embodiments of the self-tapping clamp contact are explained in more detail with reference to the accompanying drawings which show in FIG. 1 the first embodiment of the self-tapping clamp contact according to the invention with a contact slot in plan view; FIG. 3 shows a second embodiment of the self-tapping clamp contact of the invention with two contact slots in cross-section; FIG. 5 shows a self-tapping clamp contact of FIG. 4; Fig. 6a shows a third embodiment of the self-tapping clamp contact according to the invention in cross-section, Fig. 7a a fourth embodiment of the self-tapping clamp contact according to the invention during the cross-section manufacturing step; 7a in a final cross-sectional view, and FIG. 8 a schematic representation of the cut of the connected conductor in the case of a conventional self-cutting terminal contact in cross-section.

DETAILED DESCRIPTION OF THE INVENTION

In the first embodiment according to FIGS. 1 and 2, the self-tapping clamp contact has two contact arms 2a, 2b which are connected together in one piece via the connecting area 4. The two contact arms 2a, 2b are separated from one another along a notch which comprises a bay-shaped entry area 6, a contiguous contact slot 3 adjoining it, and an approximately oval relief opening 5 lying between the contact slot 3 and the connecting zone 4. It is delimited by contact surfaces 3a, 3b which extend parallel to each other. The contact surfaces 3a, 3b each form an angle a with the plane of the contact arms, i.e. with the plane in which the two contact arms 3a, 3b lie. In the example shown, the angle α is 45 degrees. The contact slot 3 is die-cut from the material of the self-tapping clamp contact J, the two contact arms 2a, 2b remaining in one common plane.

FIG. 3 shows how the connected core 10 is contacted in the self-tapping clamp contact of FIG. 1 and FIG. 3. Upon insertion of the conductor 10 into the contact slot 3, the insulation 11 in the area of the contact surfaces 3a and 3b is automatically cut off so that the conductor 12 of the conductor 10 comes into direct contact with the contact surfaces 3a, 3b and thereby electrically contacting the self-tapping terminal contact 1 and the conductor. As pointed out in FIG. 3, the stripped section of the conductor 12 bears flat on the contact surfaces 3a, 3b, so that no shear load of the conductor 12 occurs and also no chopping occurs because of the pointed edges of the contact arms 2a, 2b which are The contact surfaces 3a, 3b with the respective surfaces 7a, 7b cannot penetrate the conductor 12. The core 10 causes the contact arms 2a, 2b to twist with respect to each other, so that by this torsional stress it is permanently held and securely contacted.

In the embodiment of the self-tapping clamping contact according to the invention shown in FIGS. 4 and 5, two contact slots 3 'are provided, so that there are correspondingly three contact arms 2c, 2d, 2e which are joined together at one end in one piece. The contact slot 3 'and the contact surfaces 3a', 3b ', 3c', 3 'are made corresponding to the first shape

1 to 3, wherein the contact surfaces always engage the plane of the contact arms, i.e. the plane in which all three contact arms 2c, 2d lie. 2e. Instead of the same angle α, different angles can also be considered for the inclined alignment of the two contact slots T. In the example shown, both angles α = 45 degrees. The inclined alignment of the contact slot 31 is oriented so that the contact slots are aligned obliquely in the opposite direction. Since both angles α are the same in this example, the self-tapping clamp contact is symmetrical about the axis. Giant. 5 shows that the two connected cores 10 are, by analogy to the situation of the first embodiment of the self-tapping clamp contact (cf. FIG. 3), held firmly by torsional stress in such a way that the stripped areas of cores 10, conductors 12 are flat contact with the contact surfaces 3a '; 3b ', 3c', 3d.

The third embodiment of the self-tapping clamp contact shown in FIG. 6 has a further reduced contact slot width d relative to the minimal slit slot feasible by the cutting technique. 1 to 3, the contact arms 2a, 2b in the plane of the contact arms are pushed in one step during the pressing process (see arrow direction), and this plastic deformation results in a width d of the contact slot from 0 mm to 0.3 mm, that is to say, in this embodiment, any reduction in the spacing between the two contact surfaces 3a, 3b relative to the cutting width achievable by the contact slot width d can be achieved until they are adjacent. As can be seen from FIG. 6, the inclined alignment of the contact surfaces 3a, 3b with respect to the planes of the contact arms is also maintained in this embodiment, the two contact arms 2a, 2b being in a common plane.

A fourth embodiment of the self-tapping clamp contact is shown during the manufacturing step in Figs. 7a and 7b in its final state. Starting from the self-tapping clamp contact of FIG. 6 with the contact surfaces 3a. 3b applied to the contact, i.e. with a width d = 0 mm of the contact slot, the contact arms 2a, 2b in the common plane of contact of the contact surfaces 3a, 3b are offset transversely to the plane of the contact arms (cf. arrow 7a). after this brief displacement of the contact arms 2a. 2b reaches the final state according to FIG. 7b, in which the two contact arms 2a, 2b lie in one common plane and the contact surfaces 3a, 3b lie on each other. By short-term displacement according to FIG. 7a, this fourth embodiment of the self-tapping clamp contact is biased so that both contact surfaces 3a, 3b are pressed against each other in the direction of the common plane of the contact arms 2a, 2b by a biasing force. Also, particularly thin cables, which can no longer cause any torsion in the contact arms 2a, 2b when they are inserted into the contact slot 3, are safely contacted and permanently held due to the prestressing of the contact surfaces 3a, 3b.

Claims (5)

PATENT CLAIMS A self-tapping terminal contact for connecting electrical wires (10) without stripping, essentially a plate-like, electrically conductive metal material, with at least one substantially slit-shaped notch, each of which two contact arms (2a, 2b) are separated from each other, which the ends (4) are integrally connected to one another and which lie in a common plane, wherein at least along the partial region - the contact slots (3) of each notch, the contact arms (2a, 2b) are formed opposite to each other, substantially parallel to one another contact surfaces (3a, 3b), characterized in that the contact surfaces (3a, 3b) are punched out of a metallic material and the punched contact surfaces (3a, 3b) extend obliquely with respect to the plane of the contact arms at an angle (α) in the range from 35 degrees to 80 degrees. Self-drilling clamp contact according to claim 1, characterized in that the contact surfaces (3a, 3b) form an angle (α) of 45 degrees with the plane of the contact arms. The self-tapping clamp contact according to claim 1 or 2, characterized in that the two adjacent contact arms (2a, 2b) are each transverse to the notch formed by the contact slot (3), the relief opening (5) and the inlet region (2). 6) in the form of a bay, within the plane of the contact arms, offset so that the width (d) of the contact slot between each of the two contact surfaces (3a, 3b) belonging to each other is reduced. The self-tapping clamp contact according to claim 3, characterized in that each of the two contact surfaces (3a, 3b) belonging to each other is displaced to each other and, after a short displacement opposite one another transversely to the plane of the contact arms. the pretensioned state, wherein the contact arms (2a, 2b) lie in one common plane. Self-drilling terminal contact according to one of Claims 1 to 4, characterized in that the contact surfaces (3a, 3b) of two adjacent notches (3, 5, 6) extend in opposite directions to each other in their oblique orientation.