U.S. patent application number 09/730431 was filed with the patent office on 2001-06-07 for system.
This patent application is currently assigned to U.S. Philips Corporation. Invention is credited to Fransen, Petrus J. M., Teunisse, Antonius G. C., Van Beek, Patrick.
Application Number | 20010002622 09/730431 |
Document ID | / |
Family ID | 8240972 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002622 |
Kind Code |
A1 |
Teunisse, Antonius G. C. ;
et al. |
June 7, 2001 |
System
Abstract
A system (1) is provided which comprises a housing (2) and an
electric cable (3), which housing (2) has an EMC shielding wall (4)
with an edge (5). The wall (4) is provided with a recess (7) which
borders the edge (5). The electric cable (3) is electrically
connected to the EMC shielding wall (4) of the housing (2) at the
recess (7) via contacting means (8). Means (9, 10) are provided
substantially at the same recess (7) for absorbing any mechanical
pull loads on the electric cable (3). Thus a compact, reliable, and
safe EMC shielding system (1) is provided.
Inventors: |
Teunisse, Antonius G. C.;
(Oss, NL) ; Van Beek, Patrick; (Oss, NL) ;
Fransen, Petrus J. M.; (Oss, NL) |
Correspondence
Address: |
Jack E. Haken
c/o U.S. PHILIPS CORPORATION
Intellectual Property Department
580 White Plains Road
Tarrytown
NY
10591
US
|
Assignee: |
U.S. Philips Corporation
|
Family ID: |
8240972 |
Appl. No.: |
09/730431 |
Filed: |
December 5, 2000 |
Current U.S.
Class: |
174/360 ;
174/384; 174/657 |
Current CPC
Class: |
H01R 4/646 20130101;
H01R 13/6596 20130101; H01R 13/582 20130101; Y10S 248/906 20130101;
H01R 13/6592 20130101 |
Class at
Publication: |
174/65.00R |
International
Class: |
H02G 003/18 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 6, 1999 |
EP |
99204123.6 |
Claims
1. A system (1) comprising a housing (2) and an electric cable (3),
in which system: the housing (2) comprises an EMC shielding wall
(4) with an edge (5), a recess (7) being provided at the edge (5)
in the wall (4), and the wall (4) is provided with contact means
(8) for electrically contacting the electric cable (3) and the wall
(4) at least adjacent the recess (7), characterized in that the
electric cable (3) comprises a fastening element (9), and in that a
receiving element (10) mating with the fastening element (9) is
provided on the wall (4), shifted relative to the recess (7) along
an axis (6) perpendicular to the wall (4), into which receiving
element (10) the cable (3) and the fastening element (9) can be
introduced from a transverse direction.
2. A system (1) as claimed in claim 1, characterized in that the
receiving element (10) is an integral portion of the wall (4).
3. A system (1) as claimed in claim 2, characterized in that the
receiving element (10) comprises a second wall (4a) which is at
least substantially parallel to the wall (4) and is situated at
least at the area of the recess (7), and a space (10a) between the
wall (4) and said second wall (4a).
4. A system (1) as claimed in claim 1, 2 or 3, characterized in
that the recess (7) has an inner surface (11), while the contact
means (8) are chosen from the group formed by an electrically
conducting resilient portion at the inner surface (11) or axially
displaced relative to the inner surface (11) on the wall (4), an
electrically conducting cutting contact at the inner surface (11)
or axially displaced relative to the inner surface (11) on the wall
(4), and an electrically conducting layer on the inner surface
(11).
5. A system (1) as claimed in claim 1, 2, or 3, characterized in
that the recess (7) has a tapering shape, viewed in a transverse
direction from the edge (5).
6. A system (1) as claimed in claim 1, 2, or 3, in which the
housing (2) is provided with a cover, characterized in that said
cover closes off the recess (7) at least partly.
7. A system (1) as claimed in claim 1, characterized in that the
fastening element (9) is an integral portion of the electric cable
(3).
8. A system (1) as claimed in claim 1, 2, 3, or 7, characterized in
that the fastening element (9) has a U-shaped cross-section in
transverse direction.
9. A system (1) as claimed in claim 1, characterized in that the
fastening element (9) comprises metal and/or is provided with an
electrically conducting layer (15).
10. A housing (2) for use in a system (1) as claimed in claim
1.
11. An electric cable (3) for use in a system (1) as claimed in
claim 9.
Description
[0001] The invention relates to a system comprising a housing and
an electric cable, in which system:
[0002] the housing comprises an EMC shielding wall with an
edge,
[0003] a recess being provided at the edge in the wall, and
[0004] the wall is provided with contact means for electrically
contacting the electric cable and the wall at least adjacent the
recess.
[0005] The invention also relates to a housing and to an electric
cable.
[0006] Such a system is known from DE 297 02 513 U1. In the known
system, the contact means are at the same time means by which a
fastening of the electric cable to the housing is realized. The
contact means are for this purpose constructed as a clamping strap.
A disadvantage of the known system is that the existence of a
mechanical load on the known fastening at the same time implies
that the electrical contacting is fully and directly mechanically
loaded. This involves a comparatively high risk of the contacting
between the electric cable and the wall being broken. Another
disadvantage of the known system is that the creation of the
fastening between the electric cable and the housing by means of a
clamping strap is a comparatively labor-intensive and difficult
process.
[0007] The contact means of the known system require comparatively
much space. This is disadvantageous for an application of this
system in a comparatively small chamber. Resilient tags are
provided in the known system for counteracting this disadvantage to
a certain extent. However, this leads to another disadvantage of
the system, i.e. that the EMC shielding wall provides a less
effective EMC shielding.
[0008] It is important in a number of applications that the EMC
shielding wall should be safe to touch. That means that
electrically conducting parts of the wall and the contact means
cannot be inadvertently touched. The known system has the
disadvantage that the risk of inadvertent touching is comparatively
great because the contact means project comparatively far outward
in the known system.
[0009] The invention has for its object to counteract the above
disadvantages. According to the invention, this object is achieved
in that a system of the kind described in the opening paragraph is
characterized in that the electric cable comprises a fastening
element, and in that a receiving element mating with the fastening
element is provided on the wall, shifted relative to the recess
along an axis perpendicular to the wall, into which receiving
element the cable and the fastening element can be introduced from
a transverse direction.
[0010] In the system according to the invention, the functions of
electrically contacting the electric cable and of accommodating a
mechanical (tensile) load have been partly separated. The
separation in part of said functions has the advantage that the
full and direct mechanical load on the electrical contacting is
absent in the case of a mechanical load on the electric cable. The
transverse accommodation of the fastening element counteracts an
axial displacement of the cable relative to the wall, which might
occur as a result of the mechanical load, in a simple manner. The
mechanical load is partly accommodated by the receiving element and
the fastening element. The recess may be chosen such that the cable
introduced therein is held with clamping force. In that case, not
only the receiving element and the fastening element, but also the
recess will absorb any mechanical load which will be present. Since
the mechanical load is shared among the recess, the receiving
element, and the fastening element, the risk of breaking of the
electrical contact in the case of mechanical loads is comparatively
small.
[0011] Since the receiving element and the fastening element have
corresponding shapes, the system is simple to assemble. In
addition, the recess can be covered at least substantially entirely
by the fastening element. This gives the system the advantage that
an improved shielding of components present in the housing is
obtained as compared with the known system, for example against
dirt particles. The contacting can be screened off by the fastening
against inadvertent touching because the contacting is provided in
a direction which is axially shifted with respect to the fastening.
The advantage of this is that the system has become safer to
touch.
[0012] Finally, the system in which the electrical contacting and
accommodation of the mechanical loads have been realized in the
manner described has the advantage that the system is comparatively
compact.
[0013] In an embodiment of the system, the receiving element is an
integral portion of the wall. The receiving element and the wall
may thus be manufactured from one piece and in one and the same
operation, for example by injection molding. Preferably, the
receiving element comprises a second wall which is at least
substantially parallel to the wall and is situated at least at the
area of the recess, and a space between the wall and said second
wall. The wall is thus a double wall at the area of the recess. The
two walls have respective recesses which are axially displaced
relative to one another. A compact system for cord anchorage and
electrical contacting is achieved in a simple manner in that the
fastening element is given a shape by which it can be accommodated
in the space and hooks itself behind the second wall.
[0014] In an alternative embodiment of the system, the recess has
an inner surface, while the contact means are chosen from the group
formed by an electrically conducting resilient portion at the inner
surface or axially displaced relative to the inner surface on the
wall, an electrically conducting cutting contact at the inner
surface or axially displaced relative to the inner surface on the
wall, and an electrically conducting layer on the inner surface.
The system has become even safer to touch because the contacting is
concealed in or behind the wall. In addition, a yet more compact
system is achieved thereby.
[0015] In a favorable embodiment of the system, the recess has a
tapering shape in a transverse direction from the edge. A cable
introduced into the tapering recess will be clamped therein
automatically. No additional components are required for fastening
the cable to the housing in this case. Provided the electric cable
remains pressed home under a permanent pressure in the direction in
which the recess tapers, for example by means of a lid which closes
off the recess at least partly, the cable will automatically remain
clamped in in the recess. If the contact means in addition comprise
a cutting contact, they will cut themselves into the electric cable
while the latter is being introduced into the recess. The
electrical contacting may thus be achieved without separate
operations being necessary for it. Because of the permanent
clamping force on the cable there is an enhanced risk on a
permanent deformation of the cable and, on a result, there is a
risk on an impaired contracting during lifetime. If the electric
cable has a sheath for the purpose of contacting the contact means,
a metal bush may be provided directly below the sheath at the area
where the cable is passed through the recess so as to counteract
permanent deformation of the cable. The risk of an impaired
contacting between the electric cable and the housing in the course
of product life is improved thereby.
[0016] In a preferred embodiment of the system, the fastening
element is an integral portion of the electric cable. The cable and
the fastening element may thus be readily manufactured in one and
the same operation, for example through injection molding. The
system can thus be manufactured comparatively inexpensively.
[0017] In another favorable embodiment of the system, the fastening
element has a U-shaped cross-section in transverse direction. This
U-shaped cross-section counteracts a mechanical loading of the
contacting or of portions of the electric cable present inside the
housing owing to, for example, torsion of the cable relative to the
housing. The risk of the cable becoming detached, with the
resulting short-circuit in the system, is reduced thereby. The
system has thus become more robust and safer.
[0018] An embodiment of the system is characterized in that the
fastening element comprises metal and/or is provided with an
electrically conducting layer. Such a fastening system ensures that
comparatively small EMC leaks in the EMC shielding wall adjacent
the recess are eliminated. It is achieved in a very simple manner
thereby that the EMC shielding by the wall is yet further
improved.
[0019] The EMC shielding wall may in its entirety consist of metal,
for example of cast aluminum, but it may alternatively be
manufactured from a synthetic resin, for example PVC or
polyethylene, which is provided with an electrically conducting
layer, for example of aluminum or copper. The layer may be present
outside or inside the housing. If the layer is provided inside the
housing, the housing is suitable for an application in which it
should be safe to touch.
[0020] The electric cable may have several electrically conducting
core wires of which at least one is designed for the electrical
contacting with the wall. Alternatively, the cable may have a core
wire which is surrounded by an electrically conducting sheath which
is not in electrical connection with the core wire for the purpose
of EMC shielding, for example a coaxial cable.
[0021] An embodiment of the system according to the invention is
shown diagrammatically in the drawing, in which
[0022] FIG. 1 shows a system in plan view; and
[0023] FIG. 2 shows a detail of the system of FIG. 1 in perspective
view.
[0024] FIG. 1 shows a system 1 comprising a housing 2 and an
electric cable 3, which housing 2 comprises an EMC shielding wall 4
with an edge 5. The electric cable 3 is a coax cable which has an
EMC shielding sheath 3a. The wall 4 is provided at a side 12
thereof with an electrically conducting layer 13. A direction
transverse to the wall 4 defines an axis 6 which extends through a
recess 7 provided in the wall 4, which recess 7 is provided at the
edge 5 in the wall 4. The wall 4 is provided with contact means 8
in the recess 7. The electric cable 3 has a fastening element 9
which is introduced into a receiving element 10 which mates with
the fastening element 9. The receiving element 10 is provided on
the wall 4 so as to be axially displaced with respect to the recess
7. The receiving element 10 is formed by a second wall 4a at least
at the area of the recess 7 parallel to the wall 4 and a space 10a
between the wall 4 and the second wall 4a. The two walls 4, 4a have
respective recesses 7, 7a which are axially spaced apart from one
another. The fastening element 9 is an integral portion of the
electric cable 3 and is provided with an electrically conducting
layer 15 on a side 14 which faces the wall 4. The cable 3 and the
fastening element 9 can be introduced into the receiving element 10
from a transverse direction. In the embodiment of the system 1 as
described here, contacting between the sheath 3a and the conducting
layer 13 of the wall 4 is realized in a simple manner. A partial
cord anchorage of the electric cable 3 is realized at least
substantially in the same location through the cooperation of the
fastening element 9 with the receiving element 10. The system 1
provides a satisfactory EMC shielding which is safe to touch.
[0025] FIG. 2 shows a detail of the housing 2 of the system of FIG.
1. It is apparent from FIG. 2 that the recess 7 in the wall 4 has a
somewhat tapering shape as seen from the edge 5 in a direction
perpendicular to the axis 6, and that the recess 7a in the second
wall 4a has a U-shaped cross-section. The recess 7 has an inner
surface 11 in which electrically conducting resilient parts 8a have
been provided as the contact means.
* * * * *