Device for shaping a duct of plastic material or material that is elastically deformable

A device for shaping a duct made of plastics material or of deformable elastic material comprises two half-cages molded out of rigid plastics material and fastened together by resilient snap-fastening or hooking, the two half-cages when assembled together defining between them a housing that has the shape which is to be imparted to a portion of the duct. The invention is particularly suitable for mounting ducts of relatively large diameter in the engine compartments of motor vehicles.

The invention relates to device for shaping a duct or a pipe of a plastics 
material or of a material that is elastically deformable, such as an 
elastomer or a rubber, the duct or pipe being of a type that is suitable 
for use, in particular, in the automobile industry. 
BACKGROUND OF THE INVENTION 
Ducts or pipes of relatively large diameter which are mounted in the engine 
compartments of motor vehicles often need to be provided with shaping 
devices enabling their section shape to be modified, in particular for 
flattening purposes, and/or enabling their direction to be modified, e.g. 
in order to pass round an obstacle, with the need of such devices being 
due essentially to the lack of space available within the engine 
compartment, thus requiring certain portions of ducts or of pipes to be 
bent and flattened in order to make it possible to house them in the 
desired locations. 
At present, such shaping devices are made of rigid plastics material 
overmolded on the ducts or pipes, thereby giving rise to problems that can 
be complex. Solid cores need to be placed inside the ducts during 
overmolding of the above-specified devices and they can be very difficult 
to remove after overmolding. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of the invention is to provide a solution to those problems that 
is simple, effective, and cheap. 
An object of the invention is to provide a device for shaping a duct or a 
pipe that is capable of being mounted at any time and on any portion of 
the duct or pipe so as to change the shape and/or direction thereof, which 
device is also suitable for being removed and does not require the use of 
special tools either for being put into place or for being removed. 
To this end, the invention provides a device for shaping a duct of plastics 
material or of elastically deformable material, the device comprising at 
least two rigid pieces provided with means for fastening one to the other 
and designed to be assembled together so as to define between them a 
housing for receiving a portion of the above-mentioned duct, said housing 
being of a shape that corresponds to the shape desired for said portion of 
the duct. 
Advantageously, the means for fastening the pieces together are resilient 
snap-fastening or hooking means. 
It thus suffices to install the pieces on either side of the duct at the 
desired location and to fix them together, in particular by resilient 
snap-fastening or mutual engagement, thereby shaping the corresponding 
portion of the duct, i.e. modifying its cross-sectional shape and/or its 
direction. 
This avoids all problems associated with overmolding a sleeve of rigid 
material on a duct that is more or less deformable. 
In a preferred embodiment of the invention, the above-specified pieces are 
half-cages made up of rigidly interconnected bars. 
Each above-mentioned piece or half-piece is integrally molded out of a 
relatively rigid plastics material, e.g. out of glass fiber filled 
polyamide. 
Finally, it may be advantageous to provide on said pieces or half-cages 
fastening means or means for receiving accessories such as abutments for 
bearing against a support or members for fixing on a support.

MORE DETAILED DESCRIPTION 
Reference is made initially to FIGS. 1 to 5 which are diagrams of a first 
embodiment of the invention in which the device for shaping a duct or a 
pipe of plastics material that is made of elastomer or of rubber is itself 
constituted by two identical half-cages 10 that are suitable for being 
assembled together by resilient snap-fastening or hooking and that are 
suitable, when installed around a duct, for imparting an elliptical shape 
to its cross-section. 
Each half-cage 10 is molded out of rigid plastics material, such as a 
polyamide filled with glass fibers, and it comprises three parallel 
rectilinear longitudinal bars 12 interconnected by three parallel 
transverse bars 14 each in the form of a half-ellipse. The transverse bars 
14 are respectively at the ends and in the middle of the half-cage 10, and 
the respective longitudinal bars 12 interconnect the ends of the traverse 
bars 14 and the middle portions of said bars. One of the longitudinal bars 
12 connected together the ends of the traverse bars 14 has two 
hook-forming tabs 16 each extending between two of the transverse bars 14 
and away therefrom, tangentially to the half-ellipse defined by the 
half-cage 10, as can be seen clearly in FIG. 4. 
Each tab 16 has a catch 18 projecting from its outside face, the catch 18 
being in the form of half an arrowhead. 
The other longitudinal bar 12 interconnecting the ends of the transverse 
bars 14 of the half-cage 10 has notches 20 on its inside face, said 
notches being designed to receive the tabs 16 together with their catches 
18 of the identical other half-cage when the device is assembled. 
The tranverse end bars 14 of the cage 10 are formed with respective 
projections 22 having a sloping ramp at one end and a notch 24 of 
complementary shape at the other end (FIG. 5). Finally, positioning pegs 
26 may be formed at the ends of one of the longitudinal end bars 12 (FIG. 
3) to project in the same direction as the tabs 16, while the other end 
longitudinal bar 12 has orifices for receiving the positioning pegs 26 of 
another identical half-cage. 
The device of the invention is extremely simple to assemble: 
It suffices to place two identical half-cages 10 so they face each other as 
shown in FIG. 4, with the tabs 16 of one half-cage being in alignment with 
the notches 20 of the other half-cage, and vice versa, and then to push 
the half-cages towards each other so as to cause the half-cage to fix 
together automatically by resilient snap-fastening and hooking, with the 
catches 18 of the tabs 16 sliding over the edges of the notches 20 until 
the bars 12 are resiliently snap-fastened together. 
Any duct of circular cross-section that happens to be between the two 
half-cages 10 then takes up the elliptical shape that is defined by the 
half-cages when they are assembled together. The half-cages are made of a 
material that is sufficiently rigid and mechanically strong to ensure that 
it retains its shape even if the pressure inside the duct should become 
considerably greater than ambient pressure. 
The device of the invention is easy to disassemble: all that needs to be 
done is to push the tab 16 inwards while pulling the half-cages 10 apart 
so that they separate. 
The device of FIGS. 6 and 7 differs from that described above in that it 
makes it possible not only to modify the shape of the cross-section of the 
duct on which it is mounted, but also to modify the direction of the duct, 
e.g. by bending it through 45.degree.. 
As before, this device comprises two half-cages 30 that are identical or 
substantially identical, being made out of molded plastics material and 
being constituted by longitudinal bars 32 that extend parallel to each 
other and by transverse bars 34 in the form of half-ellipses, the 
longitudinal bars 32 being rectilinear over a portion of their length and 
curved along a circular arc in the vicinity of one end, such that a 
transverse bar 34 situated at one end of the half-cage is inclined at 
45.degree., for example, relative to the transverse bar 34 situated at the 
opposite end of the half-cage. 
The longitudinal bars 32 are parallel to the longitudinal axis of symmetry 
a of the device and the transverse bars 34 extend in planes perpendicular 
to said axis. 
To reinforce the half-cage, a transverse half-bar 36 is provided in the 
form of one-fourth of an ellipse between the two transverse bars 34 that 
interconnect the curved portions of the longitudinal bars 32, said 
transverse half-bar 36 extending between the longitudinal bar 32 that is 
situated radially outwardly relative to the center of curvature of the 
curved ends of the bars 32, and the longitudinal bar 32 interconnecting 
the middles of the transverse bars 34. 
The variant embodiment shown in FIGS. 6 and 7 also differs from that of 
FIGS. 1 to 5 in that it comprises a male type half-cage having resilient 
snap-fastening or hooking means such as the tabs 16 of the preceding 
embodiment, while the other half-cage is of the female type having notches 
for receiving the resilient snap-fastening or hooking means, with the 
half-cage 30 that is shown in FIGS. 6 and 7 being of the female type. 
In addition, the half-cage 30 has pegs 38 that project from one of the 
longitudinal bars 32, e.g. to receive a rubber shoe that is used as a 
bearing abutment on a support. 
Naturally, it is possible to provide the half-cages 10 or 30 with other 
suitable means for fastening or engaging abutment or fastening members on 
the supports. 
In both above-described embodiments, the faces of the bars 12, 14, 32, 34 
that face towards the insides of the half-cages are substantially plane or 
slightly curved and tangential to the surface of elliptical section 
defined by the half-cages. 
The number of bars, their sizes, and the material from which they are made 
depend on the stresses to which the device of the invention is to be 
subjected. The same applies to the number and sizes of the resilient 
snap-fastening or hooking means. 
In general, the invention makes it possible simply, quickly, and reliably, 
to shape a duct or pipe of plastics material or of elastically deformable 
material by means of a device that can be installed and removed without 
using special tools. 
Naturally, the half-cages as described above may be replaced by half-shells 
having solid walls or walls that are perforated to a greater or lesser 
extent. Similarly, the device of the invention may be constituted by 
assembling and fastening together more than two pieces, and it may be 
designed to modify both the direction and/or the shape of a duct, e.g. to 
impart an S-shape or a U-shape to a portion of a duct, should that be 
required.