TUYAU CHAUFFE PAR UN CONDUCTEUR ELECTRIQUE

ELECTRICALLY HEATED HOSE

Abrégé anglais

ABSTRACT OF THE DISCLOSURE
An electrically heated hose, particularly for heating
vehicle windshield washer systems, including a heating
conductor arranged longitudinally in the interior of the
hose. The heating conductor is a coaxial conductor having
a center electrical conductor, a conductive braided wire
structure conductively connected at a first end with the
center electrical conductor but otherwise separated from
the center electrical conductor by an insulating layer, and
an outer liquid-tight electrical insulating layer disposed
on the conductive braided wire structure. The second end
of the coaxial heating conductor extends out of said hose
via a liquid-tight seal where a plug-in element, for
connection to a current source, is connected to the center
electrical conductor and to the conductive braided wire
structure.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electrically heated hose, particularly for
heating vehicle windshield washer systems, comprising:
a hose having first and second ends and defining an
interior conduit;
a heating conductor arranged in said interior conduit of
said hose, extending along a length of said hose, and having
a first end which extends out of said interior conduit of
the hose adjacent said first end of said hose via a liquid-
tight seal, said heating conductor being a coaxial conductor
including a center electrical conductor, an electrical
insulating layer disposed around said center conductor, a
conductive braided wire structure disposed on said electrical
insulating layer and electrically connected to said center
electrical conductor at the second end of said heating
conductor, and a liquid-tight outer insulating layer; and
a plug-in connector, f or connection to a current
source, electrically connected to said electrical conductor
and to said conductive braided wire structure at said first
end of said heating conductor and outside of said interior
conduit of said hose.
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2. An electrically heated hose as defined in claim 1,
wherein said coaxial heating conductor extends along
substantially the entire length of said conduit.
3. An electrically heated hose as defined in claim 1,
wherein said hose includes at least one branch opening along
its length.
4. An electrically heated hose as defined in claim 1,
wherein said liquid-tight seal is disposed at said first end
of said hose.
5. An electrically heated hose as defined in claim 1,
wherein said heating conductor further includes a thermal
insulator disposed between said liquid-tight outer insulating
layer and said conductive braided wire structure.
6. An electrically heated hose as defined in claim 1,
wherein said electrical conductor and said conductive braided
wire structure each comprises copper.
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Description

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BACgGROUND OF T~E INVENTION
This invention relates to an electrically heated hose,
particularly for heating vehicle windshield washer systems,
including a heating conductor for transporting the thermal
energy to the washing fluid contained in the interior of the
. 10 hose, with the heating conductor having electrical terminals
and being an insulated unit that extends longitudinally in
the interior of the hose.
German Gebrauchsmuster ~Utility Model) No. 86/07,830
discloses an electrical heating device for the washing fluid
in vehicle windshield washer systems. In this device, the
heating wire lies as an insulated conductor in the interior
of the hose carrying the washing fluid. It has been found to
be a drawback of this system that it requires two wires,
namely the actual heating wire and the return wire, to.be
arranged next to one another in the interior of the hose. In
order to conduct current, this requires two current carrying
terminals at each input and output, involving a complicated
connection technique in which the system must be interrupted
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repeatedly in order to form branches or other connections.
This drawback becomes particularly apparent if branch nozzles
and similar elements are involved.
SUMI~ARY OF THE INV~TION
It is therefore an object of the invention to avoid the
above-described drawbacks and to provide a hose heating
system which, in addition to being easily manufactured,
involves an uncomplicated connection technique.
- This object and others to become apparent as the
specification progresses, are accomplished by the invention,
according to which, briefly stated, the heating conductor is
configured as a coaxial conductor having a copper conductor
in its interior, a conductive braided wire structure which is
separated therefrom by an insulating layer, as well as an
external insulation. The copper conductor and the braided
wire structure are electrically connected with one another in
the region of one end of the hose, and at the other free end
of the hose the heating conductor is brought out of the hose
in a sealed manner. The copper conductor and the braided
wire structure are combined, while being insulated from one
another, in a plug-in member which can be connected with a
current source by a simple plug-in process.
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The advantages of the invention are that only one
compact conductor (or cable) is disposed in the water in the
interior of the hose. The heating conductor projects only
from one end of the hose and simple T-branches can be
employed for branch nozzles. It is therefore not necessary
to interrupt the system to establish the branches, and the
heating system can be employed without complication for
hoses, fluid containers, and the like.
BRIEF DESCRIPTION OF l~EIE DRAWINGS
Figure 1 is a schematic sectional elevational view
showing a hose conduit, provided with branches, and a heating
conductor according to a preferred embodiment of the
invention.
Figure 2 is a cross-sectional view of the heating
conductor of Fig. 1.
Figure 3 is a schematic view illustrating the connection
at one end of the heating conductor of Fig. 1.
Figure 4 is a schematic view illustrating the connection
at the other end of the heating conductor.

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DESCRIPTION OF T~E PRE]FERRED ENBODINENT
Figure 1 shows a hose conduit 1 including a coaxial
heating conductor 2 disposed in its interior 11. At one free
end 12, hose conduit 1 is tightly sealed by a closure element
13. At its other free end 14, a stub 31 of a T-shaped
connecting member 3 is tightly inserted into the interior 11
of the hose. Stub 31 extends in the axial direction of
connecting member 3 and changes into a likewise axially
extending stub 32. A stub 33 projects on the side in the
middle between the two axially extending stubs 31 and 32.
One end of the heating conductor 2 leaves the interior 11 of
hose conduit 1 via the end of stub 32 which is sealed in a
known manner.
Hose conduit 1 is provided with further T-shaped
connecting members 4, 5 which are distributed over its
length. These connecting members 4, 5 may have the same
configuration as connecting member 3. Each one of the
members 3, 4, 5 is a simple hose connection, which, in
addition to being a T-shaped connecting member as shown, may
additionally be configured as an axial connector, as a Y-
shaped connector, or the like. These connecting members may
be connected, for example, directly with nozzle openings (not
shown) for spraying out washer fluid onto, for example, the

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windshields of motor vehicles or may be connected with other
connections.
The end of heating conductor 2 coming out of interior 11
of the hose conduit 1 is connected by a plug-in connector 21
with a current source 6. At the end 22 of the coaxial
conductor, i.e. in the region of the free end 12 of hose
conduit 1, a copper conductor and conductive plaited wires of
the conductor 2 are electrically connected with one another
and this conductive connection is covered by an insulating
layer, as described in greater detail below.
Figure 2 is a cross-sectional view of the heating
conductor 2. As considered from the inside out, heating
conductor 2 includes a stranded copper wire center conductor
23 that is surrounded by an electrical and thermal insulation
24 made of, for example, polyamide, and heating conductor
wire in the form of a conductive braided wire structure 25
disposed on insulation 24. This conductive braided wire
structure 25 may be, for example, a copper wire braid. A
thermal insulation 26, which may be, for example, glass silk,
is in turn disposed on braided wire structure 25. The entire
structure is encased in a bending-resistant and water-tight
insulation 27, for example, of polyamide.
Figure 3 shows the conductive connection of copper
conductor 23 and the braided wire structure 25 at the end 22

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of the conductor 2 in the region of free hose end 12. In
Fig. 3, the water-tight insulation 27 and the thermal
insulation 26 at the end 22 have been removed. Moreover, the
insulation 24 has also been removed at the end 22, e.g., by
previous lifting of conductive braided wire structure 25
away from the further structure, and the braided wire
structure 25 directly applied and soldered to the copper
conductor 23. The free end 22 of thermal conductor 2 iS then
encased in a water-tight insulation 28.
Figure 4 shows the connection of copper conductor 23 and
the conductive braided wire structure 25 to the plug-in
connector 21. At this end, the insulation 26, 27 has been
removed from copper conductor 23 and conductive braided wire
structure 25 as described in connection with Figure 3 .
Then, copper conductor 23 is electrically connected with a
short plug-in pin 211, and conductive braided wire structure
25 is electrically connected with a long plug-in pin 212.
Plug-in pins 211, 212 are then insulated electrically and
thermally against one another and the entire structure is
encased in a bend resistant and water-tight insulation 28'.
It will be understood that the above description of the
present invention is susceptible to various modifications,
changes, and adaptations, and the same are intended to be
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comprehended within the meaning and range of equivalents of
the appended claims.
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