Electrical connector

The invention relates to an electrical connector with a housing (1) of insulating material and a metal contact element (2) fittable in the housing (1). The contact element has a crimp contact region (4) to contact a first cable end (11) and a cutting clamp contact region (3) to contact a second cable (12). Such an arrangement is not suitable for contacting cables of different diameters via the cutting clamp contact region. According to the invention, the cutting clamp contact region (3) has two tension-relieving regions (5, 6), with the cutting clamp blades, which are fitted opposite one another in pairs (7, 8, 9, 10), arranged between them. Two pairs of cutting clamp blades (7, 10) are provided for small-diameter cables and two pairs (8, 9) are provided for large-diameter cables. The pairs of cutting clamp blades (8, 9) for small-diameter cables are arranged between those for large-diameter cables.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to an electrical connector having a housing made of 
insulation material and a metallic contact element, which can be arranged 
in the housing and has an insulation-piercing contact region and a crimp 
contact region which, in the direction of the longitudinal axis of a cable 
that can be introduced, adjoins the insulation-piercing contact region and 
is conductively connected to it. 
2. Summary of the Prior Art 
There are many applications for which it is desirable to be able to use the 
insulation-piercing technique. However, one disadvantage of the 
insulation-piercing technique is that the contacts are very sensitive with 
respect to the diameter of the insulated conductors with which contact is 
to be made. However, since in the normal case it is to be assumed that it 
is not known from the beginning what cable size is intended to be 
connected using an insulation-piercing contact, this technique often 
cannot be used. The reason why insulation-piercing structures are so 
sensitive with respect to diameter fluctuations is that the cutter, which 
is intended to cut through the insulation, must reach the inner conductor. 
DE 43 24 841 A1, which is representative of the prior art, has specified a 
method and a device for the power supply to optional, electrically-driven, 
special equipment devices, for example in a motor vehicle. For this 
purpose, a cable of a basic production cable set is connected by means of 
an electrical connector to a cable leading to the special equipment 
device. The electrical connector has a housing made of insulation 
material. Arranged in the housing is a contact element shaped from sheet 
metal and having an insulation-piercing contact region for the electrical 
cable and unitary with at least one further electrical connection region 
for making contact with at least one further electrical cable. The housing 
is divided into two chambers, one of which accommodates the 
insulation-piercing contact region and the other the further connection 
region. The two chambers are connected to each other via a passage, 
through which there passes a connecting web between the 
insulation-piercing contact region and the additional connection region. 
This citation does not reveal how an insulation-piercing structure can be 
used for cables with different diameters. 
U.S. Pat. No. 4,472,596 likewise discloses the use of insulation-piercing 
structures. In this case, cables or cable ends are first fixed in a 
strain-relief region and contact is then made with them by means of an 
insulation-piercing structure. In each case, one pair of 
insulation-piercing structures is connected to each other and is 
surrounded on the outside by a pair of strain-relief regions. 
U.S. Pat. No. 4,834,670 likewise discloses an electrical connector having 
an insulation-piercing contact region. This printed document discloses the 
construction of the insulation-piercing contact element in a U shape, two 
opposite insulation-piercing blades being arranged in each case on the 
limbs of the U. 
SUMMARY OF THE INVENTION 
It is the object of the invention to specify an electrical connector which 
has an insulation-piercing contact region and is suitable for cables with 
various diameters. The object is achieved by an electrical connector 
having the features of Patent claim 1. Advantageous developments are 
specified in the subclaims. 
The electrical connector has, respectively, pairs of insulation-piercing 
blades for cables with a smaller diameter and for cables with a greater 
diameter. The pairs of mutually opposite insulation-piercing blades for 
cables with the larger diameter are in this case arranged on the outside, 
and the pairs of insulation-piercing blades for cables with a smaller 
diameter are arranged on the inside. If a cable of larger diameter is 
inserted into the insulation-piercing blades, contact is made by the outer 
insulation-piercing blades. In relation to the inner insulation-piercing 
blades, various possibilities can be conceived. Either the inner 
insulation-piercing blades cut not only into the outer insulation sleeve 
of the cable, but also into the inner conductor. However, this partial 
severing does not lead to further problems, since the cable is retained by 
the strain-relief regions, and mutual contact of the two cable parts is 
ensured by the outer insulation-piercing contacts and the base plate, 
connecting these, of the metallic contact element. Alternatively, the 
inner insulation-piercing blades are plastically deformed, since they are, 
for example, more easily deformable, since they are thinner than the outer 
insulation-piercing blades, and the thicker cable is not influenced by the 
inner insulation-piercing blades. It is also possible for the actual 
solution to lie between these two extremes. 
It is particularly advantageous if the contact element can be pushed into a 
housing in the direction of the longitudinal axis of the cable that can be 
introduced. It is advantageous here if two latching positions are provided 
and, in a first initial latching position, a cable end can be introduced 
into the crimp contact region and, in a second end position, a cable can 
be introduced from above, through the housing, into the 
insulation-piercing contact region. The crimp contact region is thus 
protected against external influences and the entire contact element is 
also stabilized and protected by the housing. 
In addition, it is advantageous that the insulation-piercing region and the 
crimp region are arranged in such a way that the two cables to be 
connected to each other are aligned with each other and are arranged in 
the housing one above the other in relation to the housing base. This 
ensures that the arrangement is implemented in a very compact manner and 
does not interfere further in the course of the continuous cable, since 
the cable end to be connected is aligned with the continuous cable. 
In order to ensure reliable mounting of the cables, it is advantageous if 
the contact element and the housing have a stop for the initial latching 
position and the end position. 
The electrical connector is suitable for connecting continuous cables of 
different sizes to one cable end, or for connecting two cable ends which 
are located opposite each other and have a larger diameter to a third 
cable end. The use of the electrical connector proceeds as follows: 
firstly, one cable end is introduced into the crimp contact region, and 
the crimp connection is closed. After this, the contact element with the 
first cable end is pushed into the housing. The second cable, a continuous 
cable, is then inserted from above, through the opening in the housing, 
into the insulation-piercing contact region. Depending on the size of the 
cable diameter, only the two inner pairs of insulation-piercing blades cut 
through the insulation of the cable and make contact with the conductor, 
or the two outer pairs of insulation-piercing blades and the two inner 
pairs of insulation-piercing blades cut through the insulation of the 
cable and the outer ones make contact with the conductor. The inner 
insulation-piercing blades then also partially cut through the conductor. 
In addition, after the cable has been introduced, the strain-relief 
elements of the strain-relief regions have to be closed. This can be 
performed, for example, through the opening of the housing, that is to say 
from above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
An electrical connector is illustrated in FIG. 1. The housing 1 is 
essentially U-shaped. The opening of the U is located at the top in the 
drawing, the housing base 16 is illustrated in section at the bottom. A 
step 15 in the housing base 16 can be seen. The metallic contact element 2 
is located on the lower level of the housing base 16. In FIG. 1, the said 
contact element 2 is only partially pushed in. The position illustrated in 
FIG. 1 is designated the initial latching position. A stop 13, which 
engages on a shoulder of the housing, prevents the further insertion of 
the contact element 2 into the housing 1. The withdrawal of the contact 
element 2 from the housing is prevented by two mutually opposite sprung 
elements 17 and corresponding broadenings in the housing cross-section 18, 
on which the spring elements 17 latch in. 
In order to set up the metallic contact, the metallic contact element has 
an insulation-piercing contact region 3 and a crimp contact region 4. In 
the initial latching position of the contact element 2 in the housing 1, 
the insulation-piercing contact region 3 is already located in the 
housing, whereas the crimp contact region 4 is accessible outside the 
housing. Crimp contact region 4 and insulation-piercing contact region 3 
are conductively connected to each other. The crimp contact region 
comprises two pairs of crimp blades arranged one behind the other, of 
which those 19 further remote from the insulation-piercing contact region 
3 are used for fixing a cable end 11 having a cable sheath, and the crimp 
blades 20 arranged closer to the insulation-piercing contact region 3 are 
used for fixing the stripped conductors of the cable end 11. 
The crimp contact region 4 is adjoined by the insulation-piercing contact 
region 3. Both regions are configured in such a way that cables 11,12 
fixed herein are aligned with one another. In this case, the connected 
cables 11,12 lie one above the other in relation to the housing base 16. 
The insulation-piercing contact region 3 comprises the actual 
insulation-piercing blades 7 to 10 and two strain-relief regions 5 and 6. 
If the insulation-piercing contact region 3 is viewed in the direction of 
a cable that is to be inserted (see FIG. 3), then there are arranged, one 
behind another, a strain-relief region 5 with, for example, a pair of 
opposite tongues, which are crimped for the purpose of strain relief, a 
pair of opposite insulation-piercing blades 7, which are suitable for 
cables of a larger diameter, two pairs, arranged one behind the other, of 
insulation-piercing blades 8 and 9, which are arranged alongside each 
other and are suitable for cables of a smaller diameter, and a pair of 
insulation-piercing blades 10, which are arranged alongside each other and 
are once more suitable for cables of a larger diameter. The last element 
once more forms a strain-relief region 6 which, for example, may be 
composed of two opposite blades, which are to be crimped in order to fix 
the cable. The actual insulation-piercing contact region 3 is composed of 
a W profile with four planes, each of which has an opposite pair of 
insulation-piercing blades 7 to 10. 
Illustrated in FIG. 2 is an arrangement according to FIG. 1 in an 
installation situation. In this case, a cable end 11 is fixed at the crimp 
contact region 4. The conductors 21 of the cable 11 can clearly be seen. 
They are retained by the crimp tab 20. It can also be seen that the stops 
13 for the initial latching position are no longer visible. This results 
from the fact that, during the crimping operation, the stops are bent over 
at the same time, in order thus to make it possible for the contact 
element 2 to be inserted into the housing 1 in order to reach the end 
position. After the crimping operation, the metallic contact element 2 was 
pushed into the housing 1. At the same time, the sprung elements 17 are 
pushed further from a first taper in the cross-section of the housing 18 
to a second taper in the cross-section of the housing at 18'. Provided on 
the contact element 2 is a stop 14' for the end position. The stop strikes 
on the step 15 in the housing 1. A projection 14 enters a depression, 
which is visible in FIG. 1, in the housing wall 22. This securing means is 
intended to prevent the arrangement being influenced by tension on the 
cable end that is on the left in the figure. In the end position, a second 
cable 12 can then also be introduced into the insulation-piercing contact 
region. The cable 12 is then conductively connected to the cable end 11. 
The arrangement according to FIG. 1 is illustrated in a top view in FIG. 3. 
Identical reference symbols from FIGS. 1 and 3 have the same meaning. It 
can be seen that there is likewise provided, at the free end of the crimp 
contact region 4, a stop 23, which engages in a broadening in the housing 
1, and this avoids the crimp contact region 4 being bent or even torn off 
the contact element in the event of tension on the cable end 11.