Electrical terminal

An electrical terminal having a contact-making region for making contact with a complementary contact pin and having a connecting region for connection to an electrical conductor is described, the contact-making region including an inner contact-making spring and an outer, external spring, the contact-making spring merging into a connecting region and having at least two mutually opposite contact spring arms which are supported by the external spring, the terminal further including a web which runs transversely with respect to the insertion direction is cut out on two longitudinal sides at least on a side of the external spring opposite the contact spring arms, this web being bent inwards in such a manner that it presses from the outside onto the contact spring arm.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to an electrical terminal having a contact-making 
region for making contact with a complementary contact pin and having a 
connecting region for connection to an electrical conductor. 
2. Description of the Prior Art 
An electrical connecting terminal having a contact-making region for making 
contact with a complementary contact pin or tab and having a connecting 
region for connection to an electrical conductor, the contact-making 
region having an inner contact-making spring and an outer, external 
spring, the contact-making spring, which merges into the connecting 
region, having at least two mutually opposite contact spring arms which 
are supported by the external spring, is known from EP 700 122 A2. This 
electrical connecting terminal has in each case three pairs of contact 
spring arms, the outer contact spring arms each being connected to a side 
arm of the contact-making spring and being supported by the latter, and 
the centre contact spring arm in each case having a free end and not being 
supported. This results in the contact spring arms having different 
contact forces. If the contact forces of the inner contact spring arm are 
insufficient, then a support is required for it. 
A double flat spring contact having an external spring is known from EP 114 
187, the external spring having external spring bracket arms which run 
parallel to the contact spring arms of the double flat spring contact and 
press onto these contact spring arms from the outside. The external spring 
bracket arms in this case run essentially in the insertion direction and 
have free ends towards the end face. 
SUMMARY OF THE INVENTION 
The object of the invention is to specify an electrical connecting terminal 
in which the contact spring arms are supported by an external spring. The 
object is achieved by an electrical terminal comprising a contact-making 
region for making contact with a complementary contact pin or tab and 
having a connecting region for connection to an electrical conductor, the 
contact-making region having an inner contact-making spring and an outer, 
external spring, the contact-making spring, which merges into the 
connecting region, having at least two mutually opposite contact spring 
arms which are supported by the external spring, the terminal further 
comprising a web which runs transversely with respect to the insertion 
direction cut out at least on one side of the external spring opposite the 
contact spring arms, this web being bent inwards in such a manner that it 
presses from the outside onto the contact spring arm. 
In many applications, it is necessary for the contact spring arms of an 
electrical connecting terminal to be supported by the external spring as 
well. As is known, for example from EP 114 187, such support can be 
provided by external spring bracket arms which run essentially parallel to 
the insertion direction. This results in an external spring whose shape is 
very irregular and uneven. However, the current trend is to produce 
external springs which are as smooth as possible. The solution according 
to the invention, of cutting out a web which runs at right angles to the 
insertion direction, produces a considerably smooth external surface. 
It is possible in this case for the web to be cut out only on the 
longitudinal sides, and thus to support a contact spring arm. 
Alternatively, it is possible to split the web into two tongues whose free 
ends press jointly or in each case onto a contact spring arm. 
An electrical connecting terminal according to the invention can be 
provided, for example, for being fitted into a chamber in a plastic 
housing. It is normal to provide the external spring with latching spring 
tongues for this purpose, which make it possible for the connecting 
terminal to be latched in the housing. 
According to the invention, it is particularly advantageous that the 
latching spring tongue can be fitted on the same side of the external 
spring as the web, since the latter occupies only a small amount of space. 
The electrical connecting terminal may have, in its connection region, 
either two crimping regions or else one or more insulation-piercing 
terminal regions for making contact with an electrical conductor. 
It is particularly advantageous to use the arrangement according to the 
invention for an electrical connecting terminal having three pairs of 
contact spring arms, the centre contact spring arm in each case being 
supported by a web of the external spring.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a side view of an electrical terminal 1 according to the 
invention. The electrical terminal 2 has a contact-making region 2 for 
making contact with a complementary contact pin or tab, for example a 
blade contact. Furthermore, the electrical connecting terminal 1 has a 
connecting region 3 which, in the present exemplary embodiment, comprises 
two crimping regions 4 and 5. Each crimping region 4, 5 has two opposite 
crimping lugs which are bent inwards appropriately during crimping. The 
crimping region 4 which is adjacent to the contact-making region 2 is 
suitable for being crimped onto an electrical conductor, and the second 
crimping region, which is adjacent to it, is suitable for crimping onto 
the insulation of an electrical conductor. In other embodiments, it is 
possible to provide insulation-piercing terminal connections, for example, 
instead of such crimping regions for making contact with an electrical 
conductor. 
The contact-making region 2 comprises an inner contact-making spring 6 and 
an outer external spring 7. The contact-making spring 6 will now be 
described, first of all, with reference to FIGS. 5 to 8. As can easily be 
seen from FIGS. 5, 7 and 8, the contact-making spring has three pairs of 
mutually opposite contact spring arms 8 to 13. The centre contact spring 
arms 9 and 12 in this case have a free end. Opposite this, the 
respectively outer contact spring arms 8, 10, 11 and 13 are connected via 
a connection 14-17 on the end-face end to side arms 18-21 which support 
the contact spring arms 8, 10, 11 and 13. As can be seen particularly 
easily in FIG. 6, the contact spring arms 8-13 run towards one another as 
far as the contact-making point K, and then diverge. This forms an 
insertion opening for the complementary contact pin. 
As can be seen from FIGS. 5 and 6, the inner contact-making spring 6 has a 
spring arm base 22 which is designed essentially in a box-shape. However, 
this box tapers in the centre region of the longitudinal sides, that is to 
say in the region of the centre contact spring arms 9 and 12. This can be 
seen particularly easily in FIGS. 7 and 8. 
The external spring 7 will now be described with reference to FIGS. 9 to 
14. The external spring is constructed essentially in a box-shape. It has 
a top wall 23 and a bottom wall 24, as well as two side walls 25 and 26. 
The cross-section of the external spring tapers in the centre region of 
the side walls. The cross-section looks like a zero (0) which has been 
compressed in the centre. A latching spring tongue 27, 28 is arranged on 
each side in this region. This latching spring tongue is used for latching 
the external spring in a housing. The latching spring tongue 27, 28 is a 
tongue that has been cut out of a side wall 25, 26. As can be seen, this 
latching spring tongue is detached from the housing, but does not project 
beyond the maximum width of the external spring. This means that the 
surface of the external spring is as smooth as possible. When a contact is 
inserted, with this external spring, through a common seal, the common 
seal is thus not damaged by the latching spring tongue. 
FIG. 15 shows a section through a housing chamber 30 with a contact fitted. 
Two shoulders 31, 32 can be seen, behind which the latching spring tongues 
27, 28 latch. The shoulders 31, 32 do not extend over the entire width of 
the chamber 30, but only in the centre region, in which the contact or the 
external spring 7 has the taper. 
In the region close to the end surface, the external spring 7 furthermore 
has in each case one web 29, 30 in the side walls, the longitudinal axis 
of which web runs at right angles to the insertion direction, and which 
web is cut out on two longitudinal sides. 
The webs 29 and 30 are both bent inwards, projecting further into the 
external spring than the tapered region. This can be seen in particular in 
FIG. 10. Furthermore, the external spring 7 has stop lugs 31 to 36 bent 
around on the end face, which lugs carry out the following functions: 
First of all, these lugs ensure that, when a complementary contact pin is 
inserted, this contact pin cannot be fitted alongside, but only between, 
the contact spring arms. 
Secondly, they ensure that the contact spring arms in the electrical 
connecting terminal are prestressed, which ensures a reduced insertion 
force and an insertion force which does not start until later, as well as 
a defined spring force. 
The prestressed position can be seen particularly easily in FIG. 4, which 
shows a section through an electrical connecting terminal having an 
external spring. In this figure, it is possible to see not only that the 
stop lugs 35 and 32 ensure that the centre contact spring arms 9 and 12 
are prestressed, but also that these contact spring arms are supported by 
the webs 29 and 30.