Title of Invention

AN ELECTRICAL PLUG CONNECTOR

Abstract An electrical plug connector is illustrated and described, for connection of an electrical cable (2) to an apparatus, in particular to a sensor or an actuator, having a housing (3), having a contact mount (5) which holds a variety of contacts (4), and having an electronics circuit (6) which is arranged in the housing (3) with the electronics circuit (6) having at least one light-emitting element, in particular an LED (7) and being electrically connected to the contacts (4). In the plug connector (1), the status of the LED (7) - LED (7) illuminated or LED (7) not illuminated - can be identified particularly well, even in the presence of strong external incident light, in that the housing (3) is composed of a thermoplastic material, at least in the area of the LEDs (7), with the thermoplastic material having an additive (8) which influences the transparency and colour, and which reduces the transparency of the thermoplastic material.
Full Text Electrical plug connector
The invention relates to an electrical plug connector for connection of an
electrical cable to an apparatus, in particular to a sensor or an actuator, or for
detachable connection of two electrical cables to one another, having a
housing, having a contact mount which holds a variety of contacts, and
having an electronics circuit which is arranged in the housing with the
electronics circuit having at least one light-emitting element, in particular an
LED and be electrically connected to the contacts.
Essentially, electrical plug connections are composed of two parts, the
electrical plug connector and the mating plug connector. It can either be
used to connect an electrical cable to an electrical or electronic appliance, or
to connect two cables to one another. In the first case, the mating plug
connector is connected to the electrical housing, and in the second case it is
connected to the cable. Both the plug connector and the mating plug
connector each have a contact mount with corresponding contacts, which are
either contact pins or the corresponding sockets. Dependent on whether the
contact pins or sockets are arranged in the respective contact mount, the
associated connecting part is referred to as a plug or a socket.
In the case of plug connections such as these, it is known for the plug
connector and the mating plug connector to be mechanically connected to
one another by, for example, arranging a union nut on the plug connector,
which is screwed to the thread that is formed on the outer sleeve of the
mating plug connector. In this case, the union nut then has an internal thread
which corresponds with the thread on the mating plug connector. However,
as an alternative to this, it is also possible for a union screw to be arranged
on the plug connector and to have an external thread, so that the plug
connector with the union screw can be screwed into an outer sleeve, which
has a corresponding internal thread, on the mating plug connector.
Electrical plug connections or plug connectors such as these are used in
automation as a component of electronic equipment, sensors, actuators and
controllers. In this case, in particular, M12 and M8 types are in widespread
use, with three, four, five or eight contacts, in which case the electrical plug
connectors and mating plug connectors are known both in a straight form
and in a form angled through 90°. In the case of the latter, the housing of the
electrical plug connector is angled through 90°, so that there is an angle of

90° between the longitudinal direction of the connecting cable being held
and the longitudinal direction of the contacts. Corresponding plug
connections are known, for example, from the 2005 Catalogue
"Positionssensorik" [Position sensor system], pages 430-444 from ifm
electronic gmbh.
Electrical plug connectors such as these can either be connected as required
or can be ready-wired, in which case the contact mount and the cable are
extrusion-coated by the housing, which is then also referred to as a grip.
Finally, electrical plug connectors may also be in the form of adapters, with
the plug connector then having two contact mounts, which can each be
connected to a corresponding mating contact mount. In this case, as a rule, a
cable which has already been connected to a corresponding mating contact
mount is connected at least to one contact mount, while the other contact
mount is then generally connected to the mating contact mount of a device
or apparatus.
Electrical plug connectors of the type described initially and which are used
in particular for connection of an electrical connection to an appliance, in
particular a sensor, also have, in addition to the contact mount, an
electronics circuit having at least one light-emitting element, generally an
LED. The LEDs, of which there are up to three in practice, are in this case
used to visually signal the serviceability and in particular the switching state
of the connected sensor.
For this purpose, either an appropriate window is formed in the housing,
which is generally closed by a separate, transparent cover, or the housing is
entirely composed of a transparent material. In this way, the light beams
which are emitted from the LEDs can pass either through the transparent
cover or through the transparent material of the housing, so that the status of
the LED can be seen.
The first variant has the disadvantage that, first of all, the production is
relatively complex and costly since the various parts - housing and cover -
must be produced and connected to one another, for example by adhesive
bonding or ultrasound welding. Furthermore, the two-part configuration
means that sealing problems can also occur, so that, for applications in
which the sealing of the housing is significant, the complexity and thus also

the costs for production of a corresponding electrical plug connector rise
further.
For this reason, a transparent plastic is being increasingly used to produce
the housing in practice for electrical plug connectors which have at least one
LED. For applications in which the electrical plug connector is subject to
strong external incident light, there is a problem, however, in that it is often
no longer reliably possible to tell whether or not an LED is illuminated.
Because of the transparent material that is used, it is also possible in
particular in this case for reflections to occur of the light striking the plug
connector from the outside onto components arranged in the housing, which
it is then virtually impossible to distinguish from the light from an LED.
The present invention is therefore based on the object of providing an
electrical plug connector as described in the introduction, which avoids the
disadvantages mentioned above and furthermore can be produced as easily
as possible, and thus at low cost.
In the case of the electrical plug connector described in the introduction, this
object is achieved and the housing is composed of a thermoplastic material,
at least in the area of the light-emitting element, with the thermoplastic
material having an additive which influences the transparency and colour,
and which reduces the transparency of the thermoplastic material. Contrary
to the procedure which has been practised until now in the prior art, of using
a highly transparent material at least in the area of the light-emitting
element, the invention now proposes that the transparency of the material be
deliberately reduced. In this case this is done in a simple manner by adding
an additive to the thermoplastic material for production of the housing, thus
reducing the colour and hence the transparency of the housing.
In this case, a colour concentrate with organic and/or inorganic dyes is
preferably used as the additive, and is added to the thermoplastic material in
the form of powder or granulate. In this case, the dyes preferably have a
grey or black colour, so that the complete housing also overall has a grey to
black colour. The proportion by weight of the additive is in this case less
than 5%, preferably between 1% and 3%, and in particular about 2%, thus
making it possible to reduce the transparency by about 60% to 80%,
preferably by about 70%.

As before, the colouring of the housing according to the invention makes it
possible to tell whether an LED is illuminated from the outside through the
housing, furthermore resulting in a considerable increase in contrast, so that
the status of an LED can be seen well even when the plug connector is
subject to strong external incident light. In this case, the thermoplastic
materials which are already known from practical use, in particular
polyurethane, thermoplastic elastomer or polyvinyl chloride, can still be
used as the basic material for the housing, so that the production process for
the electrical plug connector can remain virtually unchanged.
According to one preferred embodiment of the invention, the housing of the
electrical plug connector is composed entirely of the thermoplastic material
which is provided with the additive. The housing can thus still be produced
in a single injection-moulding process. No sealing problems can occur at
junctions between different housing parts. Furthermore, the use of a housing
that is coloured overall has the advantage that the electronics circuit which is
arranged within the housing and/or is extrusion-coated by the thermoplastic
material can no longer be seen as clearly from the outside as would be the
case with a "completely" transparent housing. In consequence, a user's
attention is no longer distracted, so that he can concentrate on telling
whether the LED is or is not illuminated. Preferably the colouring of the
housing is such that the housing is completely nontransparent and only the
specific wavelength of the LED - if illuminated - can be seen from outside
the housing.
In principle, the colour of the housing of the electrical plug connector is
independent on what configuration the electrical plug connector would
otherwise have. In particular, the electrical plug connector may already be
ready-wired and connected to an electrical cable, in which case one end of
the cable is then sealed on the side of the housing facing away from the
contact mount. Since the housing is generally produced using an injection-
moulding process that end of the cable which is electrically connected to the
electronics circuit is thus also directly extrusion-coated during the
production of the electrical plug connector.
Alternatively, however, the electrical plug connector can also be designed
such that it can be wired up as required, so that the electrical plug connector
has appropriate connecting elements for connection of the individual

conductors of a separate electrical cable. Finally, the electrical plug
connector may also have two contact mounts, wherein the contacts of the
second contact mount are likewise electrically connected to the electronics
circuit, so that a cable which is connected to a corresponding mating contact
mount can then be connected to the second contact mount.
According to a final particular embodiment of the invention, which will also
be explained briefly here, the electrical plug connector has at least two
LEDs which are arranged under a transparent cover which is arranged
within the housing, in which case two symbols which are associated with the
two LEDs are formed in the housing above the cover. The two symbols have
preferably the shape of two arrows which point in opposite directions and
through which the light from the LEDs can pass.
An embodiment of the electrical plug connector such as this is particularly
advantageous when the electrical plug connector is intended to be connected
to so-called "intelligent" sensors, which have an integrated microcontroller.
In an electrical plug connector such as this, the electronics circuit of the plug
connector likewise has a microcontroller, so that the sensor is not only
supplied with electrical power via the plug connector, but data can also be
transmitted to and from the sensor via the electrical plug connector. The
symbols which are formed in the housing, in particular by being embossed,
can then indicate the direction of the actual data transfer, by the illumination
of the LED associated with the corresponding symbol. Reference should be
made to the subsequently published DE 10 2005 049 483 A1 for the specific
configuration of an "intelligent" electrical plug connector such as this.
The transparent cover, which is arranged above the LEDs, may in this case
be used in particular for focusing and guidance of the light emitted from the
LEDs, to the symbols formed in the housing. The cover is in this case
preferably in the form of a shutter such that only the light coming from the
associated LED in each case passes through the two symbols. This ensures
that, despite the physical proximity of the two LEDs within the housing,
light passes only through the symbol associated with one LED when that
LED is illuminated.
The LEDs are preferably mounted using SMD technology on a printed
circuit board associated with the electronics circuit or on a flexible

conductor film, so that a plurality of LEDs can be used even in a small
housing, as is the case with M8 plugs.
In detail, there are now a large number of possible ways to refine and
develop the electrical plug connector according to the invention. For this
purpose, reference is made on the one hand to the dependent claims, and on
the other hand to the following description of the preferred exemplary
embodiment of the invention described with reference to the attached
drawing. In the drawing:
Figure 1 shows an electrical plug connector according to the prior art,
Figure 2 shows an electrical plug connector according to the invention,
from the rear, with illuminated and non-illuminated LEDs,
Figure 3 shows one embodiment of the electrical plug connector as
shown in Figure 2, from the side and from the front, and
Figure 4 shows a second exemplary embodiment of an electrical plug
connector according to the invention, from the side and from
the rear.
The figures show various exemplary embodiments of an electrical plug
connector 1, with Figure 1 showing an electrical plug connector 1 according
to the prior art and Figures 2 to 4 showing two variants of an electrical plug
connector 1 according to the invention. The electrical plug connectors 1
illustrated in Figures 1 to 3 are used for connection of an electrical cable 2 to
an electronic apparartus, in particular a sensor, for example a proximity
switch, a temperature sensor or a flow sensor.
The electrical plug connector 1 - both according to the prior art and
according to the invention - has a housing 3, a contact mount 5 which holds
a plurality of contacts 4 and an electronics circuit 6 arranged in the housing
3. In this case, the electronics circuit 6 generally has a printed circuit board
on which, in addition to a number of electrical and electronic components, a
plurality of LEDs 7, generally up to three LEDs 7, are arranged. The LEDs 7
are in this case used as a status indication for the connected sensor. The
electrical plug connector 1 is also referred to as a cable plug or a cable

socket, dependent on the nature of the contacts arranged in the contact
mount 5 - plugs or sockets.
In order that it is possible to tell from outside the housing 3 in the case of the
known electrical plug connector 1 illustrated in Figure 1 whether the LEDs 7
arranged in the housing 3 are or are not illuminated, the housing 3 is
composed of a completely transparent plastic. As indicated in Figure 1, the
electronics circuit 6 with the electrical and electronic components arranged
on it, in particular the LEDs 7, can thus be seen through the housing 3, as
well. If the known electrical plug connector 1 is now subjected to strong
external incident light, then it is very often no longer possible to reliably tell,
especially when looked at it quickly, whether one or more of the LEDs 7 is
or is not illuminated.
In contrast, in the case of the electrical plug connector 1 according to the
invention and illustrated in Figures 2 to 4, the housing 3 is no longer
composed of "completely" transparent material, but of a thermoplastic
material to which an additive 8 which influences the transparency and
colour has been added. Thus, overall, the housing 3 has a grey or black
colour depending on the proportion by weight of the additive 8. An
illuminated LED 7 can thus, as before, be seen from outside the housing 3,
while an LED 7 which is not illuminated and the electronics circuit 6 cannot
be seen, or can be seen only poorly. This is illustrated in Figure 2 by the fact
that, in Figure 2a (LEDs off), the LEDs 7 which are arranged in the interior
of the housing 3 are illustrated just by dashed lines while, in Figure 2b
(LEDs on), the LEDs 7 are illustrated by solid lines.
Polyurethane (PUR) or polyether polyurethane is preferably used as the
thermoplastic material for the housing 3, since these plastics have a very
good resistance to oils, and are considerably better than thermoplastic
elastomer (TPE). In this case, the proportion by weight of the additive 8 is
chosen, preferably in the range from 1% to 3%, such that the transparency of
the thermoplastic material of the housing 3 is decreased by 20 to 40%,
preferably by about 30%. In this case, the resultant increase in contrast
improves the capability to see an illuminated LED 7, particularly in the
presence of incident light, considerably.

The electrical plug connectors 1 according to the invention and illustrated in
Figures 2 to 4 have a union nut 9 for mechanical connection to a
corresponding mating plug connector, which is arranged such that it can
rotate and can be moved axially to a limited extent on the contact mount 5.
The union nut 9, which has an internal thread, can thus be screwed onto a
sleeve, which has a corresponding external thread, on a mating plug
connector. In order to make is easier to screw the union nut 9 on, it has a
knurl 10 on its outer circumference. The electrical plug connector 1 also has
vibration protection, which prevents the union nut 9 from inadvertently
becoming loose from the sleeve of the mating connector. The vibration
protection is in this case provided by an appropriate embodiment of the
contact mount 5 and of the union nut 9. In order to allow a union nut 9
which has been tightened firmly to be released relatively easily again, the
union nut 9 also has a flat 11 for a spanner.
While, in the case of the electrical plug connector 1 illustrated in Figures 2
and 3, the conductors 12 in the electrical cable 2 have already been firmly
connected to the electronic circuit 6 and the electrical cable 2 has been
surrounded by the housing 3 on the side facing away from the contact mount
5, the electrical plug connector 1 shown in Figure 4 has a second contact
mount 13, which is provided for connection of a cable 2 with a
corresponding plug. An electrical plug connector 1 such as this can also be
referred to as an adaptor. In addition to this difference with respect to the
connection of the electrical cable 2, the electrical plug connector illustrated
in Figure 4 also has further differences from the plug connectors 1 illustrated
in Figures 2 and 3.
Specifically, the electrical plug connector 1 illustrated in Figure 4 is an
"intelligent" plug connector 1, which is intended for connection to an
"intelligent" sensor which has a microcontroller. The sensor can then not
only be supplied with electrical power via the electrical plug connector 1,
which likewise has a microcontroller, but data can also be transmitted from
the sensor and to the sensor. Reference is made to the subsequently
published DE 10 2005 049 483 A1 with regard to the further configuration
of the "intelligent" plug connector 1 illustrated in Figure 4, in particular with
regard to the configuration and function of the microcontroller associated
with the electronics circuit 6.

As can be seen from Figure 4a, in the case of the electrical plug connector 1
illustrated there, a transparent cover 14 is arranged between the electronics
circuit 6, which has two LEDs 7, and the upper face of the housing 3,
through which light emitted from the LEDs 7 is passed to the upper face 15
of the housing 3. Two arrows 16, 17 which point in opposite directions are
formed, in particular embossed, on the upper face 15 of the housing 3
associated with the LEDs 7, through which light from a respectively
associated LED 7 can shine. In fact, the two LEDs 7 illustrated in Figure 4a
are arranged one behind the other in the plane of the drawing - and not
alongside one another, as illustrated. The cover 14 is in this case used not
only for guidance of the light emitted from the LEDs 7 but furthermore, also
as a shutter, which is designed such that the light shines only through one of
the arrows 16, 17 in each case from the associated LED 7. The operator can
thus tell immediately, depending on which arrow 16, 17 is or is not
illuminated, the direction, for example, in which data is being transferred
through the "intelligent" electrical plug connector 1.
In addition to the embodiments of the electrical plug connector 1 illustrated
in the figures, which each relate to an embodiment angled through 90°, in
which the longitudinal direction of a connected electrical cable 2 and the
longitudinal direction of the contacts 4 of the contact mount 5 therefore form
an angle of about 90°, the electrical plug connector 1 may, of course, also be
in the form of a "straight" plug connector. Furthermore, the electrical plug
connector 1 shown in Figure 4 also has an inclined area in which the
symbols, which are in the form of arrows 16, 17, are embossed in the
housing 3 or in the upper face 15 of the housing 3.

Patent Claims:
1. Electrical plug connector for connection of an electrical cable (2) to
an apparatus, in particular to a sensor or an actuator, or for detachable
connection of two electrical cables (2) to one another, having a housing (3),
having a contact mount (5) which holds a variety of contacts (4), and having
an electronics circuit (6) which is arranged in the housing (3) with the
electronics circuit (6) having at least one light-emitting element, in
particular an LED (7) and being electrically connected to the contacts (4),
characterized
in that the housing (3) is composed of a thermoplastic material, at least in
the area of the light-emitting element, with the thermoplastic material
having an additive (8) which influences the transparency and colour, and
which reduces the transparency of the thermoplastic material.
2. Electrical plug connector according to claim 1, characterized in that
the additive (8) is a colour concentrate with organic and/or inorganic
colorant, which have a dark colour in particular grey and/or black.
3. Electrical plug connector according to claim 1 or 2, characterized in
that the proportion by weight of the additive (8) is less than 5%, preferably
between 1% and 3%.
4. Electrical plug connector according to one of claims 1 to 3,
characterized in that polyurethane (PUR), polyether-polyurethane,
thermoplastic elastomer (TPE) or polyvinylchloride (PVC) is used as the
thermoplastic material.
5. Electrical plug connector according to one of claims 1 to 4,
characterized in that the housing (3) is composed entirely of the
thermoplastic material which is provided with the additive (8).
6. Electrical plug connector according to claim 1 to 5, characterized in
that the transparency and colour of the housing (3) is such that the housing
(3) is completely intransparent and only the specific wavelength of the light-
emitting element, in particular the LEDs (7) can be seen from outside the
housing (3).

7. Electrical plug connector according to one of claims 1 to 6,
characterized in that a union nut (9) is provided and is arranged on the
contact mount (5) such that it can rotate and can be moved axially to a
limited extent, in which case the union nut (9) has an internal thread or an
external thread and can be screwed to a sleeve, which has a corresponding
thread, on a mating plug connector.
8. Electrical plug connector according to one of claims 1 to 7,
characterized in that the conductors (12) of an electrical cable (2) are
connected to the electronic circuit (6) and the electrical cable (2) is
surrounded by the housing (3) on the side facing away from the contact
mount (5).
9. Electrical plug connector according to one of claims 1 to 7,
characterized in that a second contact mount (13), which holds a plurality of
contacts, is arranged on the side of the housing (3) facing away from the
first contact mount (5) with the contacts of the second contact mount (13)
being electrically connected to the electronics circuit (6).
10. Electrical plug connector according to one of claims 1 to 9,
characterized in that a plurality of preferably differently coloured LEDs (7)
are provided, and are used as a status indication.
11. Electrical plug connector according to claim 10, characterized in that
the LEDs (7) are surface mounted devices (SMDs).
12. Electrical plug connector according to one of claims 1 to 11, having
two LEDs (7), characterized in that the LEDs (7) are arranged under a
transparent cover (14) which is arranged within the housing (3), and in that
two symbols which are associated with the two LEDs (7) in particular two
arrows (16, 17) which point in opposite directions and through which the
light from the LEDs (7) can pass, are formed in the housing (3) above the
cover (14).
13. Electrical plug connector according to claim 12, characterized in that
the cover (14) is in the form of a aperture such that only the light coming
from the associated LED (7) in each case passes through the two symbols.

14. Electrical plug connector according to one of claims 1 to 13,
characterized in that the plug connector (1) has a cross section which is
angled through about 90°, such that there is an angle of about 90° between
the longitudinal direction of a connected electrical cable (2) and the
longitudinal direction of the contacts (4).

An electrical plug connector is illustrated and described, for connection of an electrical cable (2) to an apparatus, in particular to a sensor or an actuator, having a housing (3), having a contact mount (5) which holds a variety of
contacts (4), and having an electronics circuit (6) which is arranged in the housing (3) with the electronics circuit (6) having at least one light-emitting element, in particular an LED (7) and being electrically connected to the
contacts (4). In the plug connector (1), the status of the LED (7) - LED (7) illuminated or
LED (7) not illuminated - can be identified particularly well, even in the presence of strong external incident light, in that the housing (3) is composed of a thermoplastic material, at least in the area of the LEDs (7),
with the thermoplastic material having an additive (8) which influences the
transparency and colour, and which reduces the transparency of the thermoplastic material.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=JYYnITcwirZ839L1z1JqMw==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 280080
Indian Patent Application Number 3300/KOLNP/2008
PG Journal Number 06/2017
Publication Date 10-Feb-2017
Grant Date 09-Feb-2017
Date of Filing 11-Aug-2008
Name of Patentee IFM ELECTRONIC GMBH
Applicant Address FRIEDRICHSTRASSE 1 ,45128 ESSEN,GERMANY
Inventors:
# Inventor's Name Inventor's Address
1 ANZER, GILBERT BOSKOPSTRASSE 28 88048 FRIEDRICHSHAFEN
2 MEHNERT, WOLFGANG ZWANZIGERSTRASSE 16, 88131 LINDAU
PCT International Classification Number H01R 13/717
PCT International Application Number PCT/EP2007/001182
PCT International Filing date 2007-02-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102006006726.6 2006-02-13 Germany