Note: Descriptions are shown in the official language in which they were submitted.
1l)4849~
This invention relates to an improvement in multi-
element type radiators made from synthetic plastic material.
Multi-element type radiators have-vertical water
channels and upper and lower collecting channels composed of
shell-shaped headpieces. The hubs of adjacent headpieces are
connected with each other by screwed in nipples or by welding.
With multi-element radiators of steel or cast iron the verti-
cal water channels may have any desired cross section since
the said materials have a sufficient rigidity to ensure that
10 the channels are not deformed even with an unfavorable shape
of the cross section. In the case of radiators of synthetic
plastic material the vertical water pipes should have a cross
section such that in spite of the relatively low stability of
this material, deformation is held within acceptable limits.
It has, therefore, been proposed to use water pipes with cir-
cular cross section as such a geometrical shape ensures the
highest possible resistance to internal pressure (cf. German
Patent 2,140,486 and German Utility Model 6,601,479).
Another weak point of multi-element radiators lies
in the region of the headpieces. With the known shell-like
shape of the headpieces a so-called accordeon effect is ob-
served if the stability of the material is too low, i.e. the
multi-element radiator expands in axial directions of the col-
lecting channels. With radiators of steel this expansion is
hindered by longitudinal tie rods which are secured by welding
with the hubs of the terminal elements.
An expansion in axial direction can also be avoided
by connecting both hubs of a headpiece by welded-in rods or
to provide the headpieces with axial recesses the bases of
1~4~491
which are then welded together. But this means considerable
expenditure of work and with radiator elements of synthetic
plastic material such a manufacturing method is difficult to
carry out. Moreover, the expansion is not always sufficiently
limited. The shell-like regions besides the rods or recesses
are still subject to heavy deformations.
It is the object of the present invention to confer
upon the headpieces of radiator elements of synthetic plastic
material a shape!such than an expansion in axial direction is
hindered. Additional stiffening elements are not normally
necessary but may be applied, if desired.
Accordingly, the invention provides a radiator ele-
ment of synthetic plastic material and comprising: a cylindri-
cal top tube section; a cylindrical bottom tube section having
its axis parallel with that of the top tube section; and a
plurality of water pipes extending generally vertically between
said tube sections with their axes in a plane perpendicular
to the axes of said tube sections, each of the water pipes be-
ing connected at its respective ends with the top and bottom
tube sections such that each of the water pipes is radial where
it meets the cylindrical tube sections.
The invention will now be described in further de-
tail and by way of a preferred embodiment with reference to
the accompanying drawing in which;
Figure 1 is a partially sectionedfront elevation of a
portion of a radiator made up of radiator elements according to
the invention; and
Figure 2 is a front view of one of the radiator ele-
ments and including compound section line I-I on which
- 3 -
1~48491
Fig. 1 is partly sectioned.
Figure 1 shows a part of a radiator made up of a
plurality of radiator elements such as that seen in Figure 2.
This radiator element includes respective upper and lower tube
sections 1, 1' having parallel axes and interconnected by six
generally vertical water pipes 2a, 2b, 2c, 2d, 2e and 2f.
The pipes are spaced symmetrically about an axis containing
vertical diameters of the tubes 1, 1' and have their axes in
a plane perpendicular to the axes of the pipe sections. The
tubes 2a ans 2f, 2b and 2e, and 2c and 2d are respective mirror
images of one another about the vertical axis between the tube
sections. As seen in Figure 2, the end portions of the generally
vertical tubes are cranked or bent so that they engage the
tubes 1, 1' radially.
The tube sections 1 and 1' are reinforced by respec-
tive rings 3, 3' to strengthen the element and the assembled
radiator.
The radiator element shown in Figure 2 is assembled
with other elements by interconnecting the elements at tubes
1, 1' as seen in Figure 1. Also ends of the radiator are closed
by caps such as cap 4 where no connection is to be made and
other ends have the necessary connectors (not shown).
The vertical water pipes are reinforced by continuous
compressed seams, formedduring blow molding, and local stif-
fening webs 5 are formed by punching out sections of the com-
pressed seams. Similarly, knobs 6 are formed on the pipes to
engage similar knobs on other elements to rigidify the radiator
structure on assembly.
The radiator elements can be producted from any suit-
-- 4
161 4~491
able synthetic plastic material by blow molding.
The mechanical stability of the tube sections is in-
creased by the use of stiffening rings 3 in the form of half
shells which are inserted in the blow mold cavity and then
welded with the tube sections after blow molding. On assembly,
the individual radiator elements are welded together at the
end-faces of the tube sections 1, 1' to thereby create cylin-
drical collecting channels which are not constricted internally
at the joints and which are sufficiently strong to resist all
anticipated internal pressures in radial directions.
The vertical water pipes do not end in shell-like
headpieces but directly in the cylindrical tube sections, with
the water pipes entering the tube sections radially. To this
effect the upper portions of the vertical water pipes are more
or less curved, (See Figure 2), depending on their respective
positions. Such a construction is impossible with steel plate,
whereas with a radiator of synthetic plastic material the en-
tire element, i.e. the cylindrical tube section with the ver-
tical water pipes can be produced in one working step, for
example by blow molding.
By connecting the end-faces of the cylindrical tube
sections of adjacent radiator elements, cylindrical collecting
channels are formed the surface of which is parallel to the
channel axis and, therfore, accordean-like expansion is kept
to a minimum. Because of the cylindrical shape of the tube
section the collecting channels have an optimum resistance to
internal pressure.
In order to avoid weak points in the upper and lower
portions of the water pipes where they run into the tube sec-
~¢)48491
tion it is advantageous to diminish the diameter of the pipestowards the junction with the tube sections. By this reduction
in the cross section, hoop stresses in the pipes are reduced and
the radiator element is effectively further stiffened in the
region of the headpieces without thickening the pipe walls.
~ The individual water pipes may be further stiffened
by connecting them by means of continuous or intermittent webs.
In the blow molding process there is generally pro-
duced first a radiator eleme~t the vertical water pipes of
which are connected with each other by continuous webs. These
webs are formed when the pipes are produced by compressing the
extruded tube in the blow mold. If desired, the webs can be
punched out in the blow mold or in a later process. For rea-
sons of stability it is preferred to leave the webs at least
partially.
-- 6
