U.S. patent number 3,687,194 [Application Number 05/043,534] was granted by the patent office on 1972-08-29 for ribbed pipe unit.
Invention is credited to Gunter Scholl.
United States Patent |
3,687,194 |
Scholl |
August 29, 1972 |
RIBBED PIPE UNIT
Abstract
The production of ribbed heating pipes and ribbed pipe units in
which ribs consisting of plates of sheet metal which are provided
with recesses of a size and shape in accordance with that of the
outer surface of the core pipe or pipes are applied tightly upon
the latter so as to project radially therefrom. The edges of these
recesses in the rib plates are additionally provided with grooves.
A metal, for example, aluminum, is then cast in a suitable mold
between the adjacent rib plates so as to form jacket sections
around the core pipe in which the rib plates are embedded. This
metal also penetrates through and fills out the grooves in the
edges of the apertures of the rib plates and thereby connects the
adjacent jacket sections to each other.
Inventors: |
Scholl; Gunter (6549
Pianezzo/Pando, CH) |
Family
ID: |
27181983 |
Appl.
No.: |
05/043,534 |
Filed: |
June 4, 1970 |
Foreign Application Priority Data
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Jun 13, 1969 [DT] |
|
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P 19 30 040.4 |
Jul 31, 1969 [DT] |
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P 19 38 928.7 |
Feb 16, 1970 [DT] |
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P 20 06 893.3 |
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Current U.S.
Class: |
165/180; 165/151;
165/182; 165/DIG.522; 29/890.046; 165/181 |
Current CPC
Class: |
F28F
1/12 (20130101); F28F 1/32 (20130101); B22D
19/0063 (20130101); B21C 37/22 (20130101); Y10T
29/49378 (20150115); Y10S 165/522 (20130101) |
Current International
Class: |
F28F
1/12 (20060101); B21C 37/15 (20060101); B21C
37/22 (20060101); B22D 19/00 (20060101); F28f
021/00 () |
Field of
Search: |
;285/137R,187,284,288,289 ;165/180,181,182,151
;29/157.3A,157.3C,157.3B ;164/111 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
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|
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588,712 |
|
Dec 1959 |
|
CA |
|
1,392,332 |
|
Feb 1965 |
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FR |
|
66,793 |
|
Jan 1893 |
|
DD |
|
Primary Examiner: Arola; Dave W.
Claims
Having thus fully disclosed my invention, what I claim is:
1. A heat-exchanger structure comprising a metallic core tube; a
multiplicity of metallic fin plates spaced along said tube and
formed with openings complementary to and of approximately the same
outer dimensions of said tube whereby the walls of said openings
closely hug the outer surface of said tube and are perpendicular
thereto, said plates being formed with recesses along said walls
spaced about the periphery of said tube and open in the direction
thereof; and a sheath of cast metal surrounding said tube between
said plates and extending monolithically through said recesses on
opposite sides of each plate while lying against opposite faces of
each plate along the walls thereof, said cast metal filling said
recesses and forming a bead along each of said faces.
2. The structure defined in claim 1 wherein said sheath is
unitarily and monolithically formed with at least one radially
projecting rib between said plates.
3. The structure defined in claim 2 wherein each of said plates
comprises a pair of plate halves lying in a common plane and
defining a junction line between the halves.
4. The structure defined in claim 3 wherein the plate halves of
each plate are formed with dovetail cutouts opening toward the
respective line, the cast metal of said rib filling said
cutouts.
5. The structure defined in claim 1 wherein a plurality of such
tubes traverses each of said plates and is surrounded by a
respective said sheath.
6. The structure defined in claim 1 wherein said recesses are of
outwardly widening dovetail configuration.
7. The structure defined in claim 1 wherein said tube has a
flattened cross section.
8. The structure defined in claim 1 wherein said tube has a
generally polygonal cross section.
Description
FIELD OF THE INVENTION
The present invention relates to a method of producing ribbed
heating pipes the ribs or rib sections of which are provided with
apertures or recesses of a size and shape in accordance with those
of the core pipe or pipes and are connected to each core pipe so as
to be in good heat conduction therewith by means of a metal which
is cast in a liquid condition between them and is then cooled.
BACKGROUND OF THE INVENTION
There are numerous methods known for producing ribbed heating pipes
on which the ribs are conductively connected to the core pipe and
extend transverse to its longitudinal axis. Apart from the known
method of producing such ribbed heating pipes by winding straight
or corrugated metal strips around the outer surface of the core
pipe, it is probably the most conventional method to punch the ribs
out of sheet metal and to secure them to the core pipe. These ribs
may be punched out so as to have an aperture or neck in accordance
with the outer shape and diameter of the pipe so as to permit them
to be slipped successfully over the pipe. A mechanically solid and
heat-conductive connection between the pipe and the slipped-on ribs
may be attained by dip-coating in zinc. Such ribs may also be
connected to the core pipe by welding them individually thereto
either electrically or by autogenous welding which may be done more
or less automatically on special machines. At least for heating
pipes for lower temperatures it is also possible to attain a
mechanically secure and heat-conductive connection between the pipe
and its rib by expanding the pipe either mechanically or
hydraulically.
According to still another known method of producing ribbed heating
pipes, each rib consists of two or more sections which are then
connected by electric butt-welding to a core pipe or even to
several core pipes simultaneously. The ribbed pipes which are
produced according to this method are usually employed only for
very particular purposes especially because of their high cost of
production.
OBJECT OF THE INVENTION
It is an object of the present invention to provide ribbed pipes of
the type as first described above which are designed so as to
insure that a good mechanical and heat-conductive connection will
be attained between the ribs and the core pipe or pipes and the
ribbed pipes may also be produced in a very simple manner and at a
very low cost.
SUMMARY OF THE INVENTION
The present invention for attaining this object consists in
providing the edges of the apertures or recesses in the ribs or rib
sections which engage with the outer peripheral surface of a core
pipe with shallow grooves, for example, of a dovetailed or other
shape which form channels between the opposite sides of the ribs.
Another feature of the invention consists in connecting the ribs to
the core pipe by casting a metal between the adjacent ribs so as to
form a jacket around the core pipe in which the ribs are embedded.
In this casting operation, the liquid metal also penetrates through
and fills out the groovelike channels in the ribs or rib sections
and thus connects the adjacent sections of the jacket at both sides
of each rib to each other. Therefore, when this metal has cooled,
the ribs or rib sections will be rigidly secured to the core pipe
by the jacket sections at both sides of each rib or rib sections
and also by the metal which fills out the groovelike channels and
integrally connects these adjacent jacket sections to each
other.
Such a ribbed pipe according to the invention may consist of an
individual core pipe and the ribs thereon, but the invention also
results in a ribbed pipe unit which consists of a plurality of core
pipes which preferably extend parallel to each other and are
connected to each other by the ribs or rib sections which extend
transversely to all of the core pipes. I also design the mold in
which the casting operation is carried out for connecting the ribs
or rib sections to the core pipe or pipes so that in the same
operation radially extending fins or finlike projections are cast
on the jacket which project from both sides of each rib or may
connect the adjacent ribs to each other by extending in the
longitudinal direction of the core pipe and at suitable distances
from each other. If each of the ribs consists of a pair of plates
in alignment with each other, and each of these plates has one edge
which abuts against the corresponding edge of the other plate and
is provided with a semicircular aperture the edge of which engages
with the core pipe and is provided with the mentioned groovelike
channels, the invention further provides that two diametrically
opposite fins or finlike projections extending radially from the
core pipe along the abutting edges of the two rib plates and thus
also connects these edges to each other. If desired, these abutting
edges of the two plates forming one rib may be further provided
with grooves in corresponding positions, for example, of a
dovetailed shape, which during the casting operation will likewise
be filled out with the casting metal for further improving the
connection between the fins or finlike projections and the two
plates which together form one rib and also the connection between
these two plates.
If the core pipe and the jacket which is cast around it consist of
two different materials and the material of the jacket has a higher
coefficient of thermal expansion than the material of the core
pipe, the difficulty arises that, although the jacket when in a
cold condition is shrunk tightly upon the core pipe, it may
slightly separate in radial directions from the core pipe when both
of them are heated so that the jacket would then not be in positive
thermal contact with the core pipe.
To insure a positive thermal contact between the core pipe and the
jacket when heated, despite the different coefficients of thermal
expansion of the materials of these two elements, I provide that
annular grooves are cut at suitable distances from each other into
the outer wall surface of the core pipe or that, in place of such
grooves, a continuous screw thread is cut into this surface. These
annular grooves or this screw thread should be provided with flanks
which extend substantially at right angles to the longitudinal axis
of the core pipe. This has the advantage that, when the jacket
expands more than the core pipe and disengages slightly from the
latter in radial directions, the flanks of the annular grooves or
of the screw thread will remain in direct contact with the
corresponding flanks of the annular grooves or of the screw threads
which are molded into the jacket surrounding the core pipe. Thus, a
large surface area of the core pipe and of the jacket will remain
in tight and heat-conductive engagement with each other.
A preferred method of producing a ribbed pipe according to the
invention comprises the steps of inserting the core pipe into a
continuous channel which is formed between two mold sections when
they are moved against each other, inserting rib plates in the form
of equal pairs from the outside into the two mold sections through
slots which are provided in these sections by pressing these pairs
of rib plates from the opposite sides by means of a pair of press
plungers tightly against the outer surface of the core pipe and
against each other, then casting the metal through a plurality of
channels within the mold into the cavities remaining in the mold,
and, after the casting metal has cooled, drawing the two mold
sections away from each other and thus also from the finished
ribbed pipe so that the latter may be removed from the mold.
This method of production may be employed very economically for
manufacturing ribbed pipes on which the rib plates are spaced not
less than approximately 5 mm from each other. If, however, the rib
plates are to be spaced at still smaller distances from each other,
the deformations of the mold sections which are caused by the
heating and cooling thereof reduce the service life of such a mold
to such an extent that it may be no longer economical.
In order to permit an economic production also of ribbed pipes with
core pipes either of a circular or flat cross section and with ribs
or rib plates which are only spaced at a distance of approximately
1 mm from each other, the present invention further provides that
the ribs or rib sections are stacked on each other so that the
adjacent ribs or rib sections of the stack are separated by
subsequently removable spacing strips, that the core pipe or core
pipes are inserted into the channel-like spaces of this stack which
are formed by the apertures in the ribs and spacing strips, that
thereafter the metal is cast into the spaces remaining at the
inside of the stack, and that, after the casting metal has cooled
and the ribs or rib sections are secured by this metal to the core
pipe or pipes, the spacing strips are again withdrawn from the
ribs.
If according to the inventive method a ribbed pipe unit is to be
produced which is especially suitable for being employed as an
engine radiator for an automobile, the rib plates are preferably
bent at z-shaped angles adjacent to the edges of their recesses
facing the core pipes. Each z-shaped web of each rib plate and the
arm which is connected thereto then forms together with the
corresponding arm of the adjacent rib plate an open casting channel
which is open toward the core pipe and connected by the grooves in
the wall of the recess forming this channel to the adjacent section
of the same pipe.
DESCRIPTION OF THE DRAWING
These and additional features of the present invention will become
more clearly apparent from the following detailed description
thereof which is to be read with reference to the accompanying
drawing, in which
FIG. 1 shows a plan view of one of the two plates forming a
rib;
FIG. 2 shown a cross section which is taken along the line II -- II
of FIG. 3 of an individual ribbed heating pipe;
FIG. 3 shows a longitudinal section of the same pipe, which is
taken along the line III -- III of FIG. 2;
FIGS. 4 to 6 show diagrammatic cross sections of the most essential
parts of the apparatus for producing a ribbed pipe according to
FIGS. 2 and 3 and illustrate three steps of the method of
production of such a pipe;
FIGS. 7 and 8 show diagrammatic cross sections of two ribbed
heating pipes each of which is provided with a core pipe of an oval
cross section;
FIGS. 9 to 11 show diagrammatic cross sections of three pipe
combinations each of which consists of three parallel core pipes
which are connected to each other by pairs of rib plates;
FIG. 12 shows a cross section which is taken along the line XII --
XII of FIG. 13 of a ribbed pipe which is provided with cast-on fins
or finlike projections;
FIG. 13 shows a longitudinal section of this pipe which is taken
along the line XIII -- XIII of FIG. 12;
FIGS. 14 and 15 show longitudinal sections of a core pipe and a
pipe jacket which are connected to each other by rectangular screw
threads and are illustrated in their relative positions at room
temperature and when heated;
FIG. 16 shows a plan view of a rib plate for a heating unit which
is composed of a plurality of parallel flat ribbed pipes;
FIG. 17 shows a cross section of the flat core pipes for such a
heating unit;
FIG. 18 shows a plan view of a removable spacing strip for the
heating unit according to FIGS. 16 and 17;
FIG. 19 shows a longitudinal section of an assembling plate for
assembling the pipe unit;
FIG. 20 shows a cross section of the assembled pipe unit, as seen
in a direction vertical to the plane of FIGS. 16 to 18, and parts
of which are enlarged for better demonstration; while
FIGS. 21 to 24 illustrate similar to FIGS. 16, 17 20 and 21, the
different parts of a futher modification of the invention.
SPECIFIC DESCRIPTION
As illustrated in FIGS. 1 to 3 of the drawings, a ribbed heating
pipe according to the invention comprises a plurality of pairs of
equally shaped (identical) flat rectangular plates 1 which are to
be secured at suitable distances from each other to a core pipe 2
so as to project radially therefrom and form heating ribs thereon.
The two plates 1 of each pair are placed in alignment and abutting
engagement with each other and each of the abutting sides or edges
of the two plates is provided with a semicircular recess 3 of a
diameter D which corresponds to the outer diameter D of the core
pipe 2, as shown in FIGS. 2 and 3, and each of these recesses 3 is
provided with a central groove 5 of a dovetailed shape and two
lateral grooves 6 of a substantially semicircular shape. Each of
these grooves 5 and 6 has a relatively shallow depth t.
A plurality of these pairs of rib plates 1 when combined with a
core pipe 2 form a ribbed pipe 7, a short section of which is
illustrated in FIG. 3. For securing each pair of these rib plates 1
to the core pipe 2, the edges 4 of their recesses 3 are applied
against the outer surface of the core pipe 2 and a suitable metal
9, for example, aluminum, is cast between the adjacent pairs of
plates 1 around the core pipe 2 so that, when cooled, a shell or
jacket 10 will be formed tightly around and in heat-conductive
engagement with each of the adjacent sections of the outer pipe
surface 8 between the rib plates 1. The mold which is required for
this casting process is additionally provided with annular grooves
at both sides of the rib plates 1 so that the liquid metal 9 will
also penetrate through these grooves and also form small annular
flanges (Beads) 11 at both sides of each plate 1 in which the edges
4 of the recesses 3 are embedded. The metal 9 then also fills out
the grooves 5 and 6 in plates 1 and thus connects the adjacent
sections 13 of jacket 10 integrally with each other.
FIGS. 4 to 6 illustrate three successive steps in carrying out the
casting operation by means of a mold 14. This mold essentially
comprises two equal mold sections 15 each of which is provided with
a trough-shaped recess 16. When the mold sections 15 abut against
each other, these two recesses 16 together form a continuous
longitudinal channel 17 containing the core pipe 2. Both mold
sections 15 are further provided with a plurality of transverse
slots 18 which are spaced from each other at the distances at which
the rib plates 1 are to be spaced from each other. On both sides of
each of these mold sections 15, framelike supporting members 20 are
provided which serve as supports for the rib plates 1 and are
provided with inner guide slots 19 into which the rib plates 1 may
be inserted.
At the beginning of the casting operation, the two mold sections 15
are at first moved toward the core pipe 2 in the manner as
illustrated in FIG. 4, so that this pipe 2 will be located within
the channel 17. After the rib plates 1 which are to be secured to
the core pipe 2 have also been inserted into the supporting members
20, these rib plates 1 which are thus combined with each other into
a set are pushed by means of press plungers 21 at both sides of
frame members 20 so far in the direction of the arrows 22 into the
transverse slots 18 of the mold sections 15 until the edges 4 of
the recesses 3 of rib plates 1 abut tightly against the outer
surface 8 of the core pipe 2. As may be seen particularly in FIG.
5, rib plates 1 are held in this position by the press plungers 21
so that the casting operation may then be carried out. During this
casting operation, liquid metal, preferably aluminum, is injected
through the longitudinal channel 23 in the lower part of mold 14
and from this channel 23 through the different cross channels 24.
This metal when cooled connects the rib plates 1 and the core pipe
2 securely to each other in the manner as previously described in
detail.
When the casting metal has cooled, the two mold sections 15 are at
first drawn only slightly away from each other so as to insure that
the solidified metal will properly separated from the walls of the
mold. Thereafter, the two mold sections 15 are pulled fully away
from such other to the position as shown in FIG. 6, and they will
then also take along the supporting members 20 and the press
plungers 21. The completed ribbed pipe 7 may then be removed from
the mold 14 or it may be shifted in the mold in a direction
vertical to the plane of the drawing for being provided with
further ribs. As soon as a new core pipe 2 has been shifted
longitudinally for being provided with further ribs, the mold
sections 15 and also the supporting members 20 are moved to their
starting positions as shown in FIG. 4, so that a new casting
operation may thereafter be carried out.
FIGS. 7 and 8 illustrate diagrammatically individual ribbed pipes
25 each of which has a core pipe 26 of an elliptical cross section.
The walls of the recesses 27 in the rib plates 1 which are shaped
so as to fit tightly around the core pipe 26 are also in these
cases provided with grooves 28 of any suitable shape which in the
subsequent casting operation are filled out with the casting metal
to connect the adjacent jacket sections to each other.
Each of FIGS. 9 to 11 illustrates a pipe unit 29 which is composed
of three parallel core pipes 30, 31 and 32, respectively, which are
connected to each other by pairs of rib plates 1. Core pipes 30
have a circular cross section, core pipes 31 have a drop-shaped
cross section, and core pipes 32 have an elliptical cross section.
The walls of the recesses 27 in each pair of rib plates 1 are again
provided with suitable grooves 28. These pipe units 29 are produced
in the same manner as the individual ribbed pipes as previously
described and their rib plates 1 are likewise secured to the core
pipes 30 to 32, respectively, by a casting metal 9.
FIGS. 12 and 13 illustrate a ribbed pipe 23 which is similar to the
ribbed pipe 7 as shown in FIGS. 2 to 3 and again comprises a core
pipe 2 to which pairs of rib plates 1 are secured. The two mold
sections 15 for producing this ribbed pipe 33 are, however,
provided with additional recesses to permit short fins 34 to be
cast on each of the rib plates 1, as illustrated in cross section
in the upper part of FIG. 13. Furthermore, in addition to the
grooves 5 and 6 in each pair of rib plates 1, the adjacent edges 35
of the two plates are also provided with dovetailed recesses 36
through which the casting metal 9 penetrates during the casting
operation in the manner as indicated in FIGS. 12 and 13 so as to
form webs 37 which connect the fins 34 on both sides of each rib
plate 1 securely to each other.
Instead of such short fins 34 on each rib plate 1, it is also
possible to cast continuous fins 38 on the rib plates 1 which then
connect the adjacent plates 1 to each other in the manner as
illustrated in the lower part of FIG. 13. The recesses 36 in each
pair of rib plates 1 are also in this case filled out with casting
metal 9 so that the webs 37 which are then formed connect the
individual fins 38 to each other.
In order to attain a very secure and highly heat-conductive
connection between the core pipe 2 and the jacket 10, it is of
advantage to cut a screw thread 39 into the outer wall 8 of the
core pipe 2. This screw thread 39 has a square or rectangular cross
section so that its heated flanks 40 extend at right angles to the
longitudinal axis of pipe 2. While the core pipe 2 is made of
steel, cast iron or the like, the jacket 10 consists of aluminum
which has a thermal coefficient of expansion approximately twice as
high as that of steel. When this jacket 10 after being cast has
cooled to room temperature, it will be tightly shrunk upon the core
pipe 2 and its material will be subjected to a tensile stress up to
its yield point. If, for example, the core pipe 2 together with the
jacket 10 is then heatd to a temperature of, for example,
300.degree. C., jacket 10 will expand considerably more than the
core pipe 2 and, despite its initial tension which prevails at room
temperature, its diameter will increase and it will therefore
separate slightly from the core pipe 2 in the manner as indicated
in FIG. 15. However, since the screw thread 39 is cut into the
outer wall surface 8 of core pipe 2, there will still be an
uninterrupted heat conduction between the core pipe 2 and the
jacket 10 due to the engagement of the vertical flanks 40 of the
screw thread 39 of core pipe 2 with the corresponding vertical
flanks 40 of the jacket 10. This uninterrupted heat conduction is,
however, fully attainable only, despite the increase in the inner
diameter of jacket 10, if the flanks 40 of the screw threads of
pipe 2 and thus also the corresponding flanks 41 of the jacket 10
extend at approximately right angles to the longitudinal axis of
the core pipe 2. If the flanks 40 and 41 of the screw threads would
be made at considerably smaller angles, they would at least
slightly separate from each other.
FIGS. 16 to 20 illustrate diagrammatically the mode of production
of a heating unit which consists of a plurality of flat pipes which
are provided with ribs which may be spaced at a very short
distance, and as little as about 1 mm, from each other. The
individual rib plates 42, one of which is shown in FIG. 16, may be
punched, for example, out of sheet aluminum and be provided with
transverse slots 43 into which the individual flat pipes 44 of a
set 45 of such pipes, as shown in FIG. 17, are to be inserted. The
edges of these transverse slots 43 are again provided with small
recesses 6 through which the liquid metal 9 will penetrate during
the subsequent casting operation.
In order to insure that the individual rib plates 42 will be
uniformly spaced from each other, spacing strips 46, as shown in
FIG. 18, are inserted between the rib plates 42 during the assembly
of the pipe unit. These spacing strips 46 which are preferably
punched out of sheets of asbestos, cardboard or the like have a
thickness s which corresponds to the distance between the adjacent
rib plates 42. They are also provided with transverse slots 47 of a
width b which is at least equal to the distance a between the
opposite edges of the recesses 6 in the edges of the transverse
slots 43 of rib plates 42, as shown in FIG. 16. Furthermore, the
edge 48 of each of these spacing strips 46 is also provided with
recesses 49 which are offset in the longitudinal direction of the
strip relative to the transverse slots 47 and have a dovetailed
shape. The bottom edge of each of these dovetailed recesses 49 is
further provided with a central groove 50.
For assembling the rib plates 42 with the spacing strips 46 and
connecting them to each other, an assembling plate 51 is employed,
as shown in cross section in FIG. 19. This assembling plate is
provided with supporting ribs 52 of a dovetailed cross section, and
each of these ribs 52 is provided with a central projecting ridge
53. The cross-sectional shape of the ribs 52 including the ridges
53 corresponds to that of the recesses 49 and 50 in the spacing
strips 46.
FIG. 20 finally illustrates the manner in which the flat-pipe
heating unit is assembled. At first, the required number of rib
plates 42 and intermediate spacing strips 46 are stacked on each
other so that the transverse slots 43 and 47 will be in alignment
with each other. The entire stack may then be held together by the
supporting ribs 52 on the assembling plate 51 which engage into the
corresponding recesses 49 in the spacing strips 46. The projecting
ridges 53 on ribs 52 then engage into the grooves 50 of the spacing
strips 46 and also into corresponding grooves 55 which are provided
in the edges 54 of the rib plates 42 and thus prevent the rib
plates 42 from shifting relative to each other and to the spacing
strips 46. The supporting ribs 52 and their projecting ridges 53 on
the assembling plate 51 may be either inserted into the
corresponding recesses of the complete stack of rib plates 42 and
spacing strips 46 or the rib plates and spacing strips may be
stacked upon each other on the assembling plate 51.
When the rib plates 42 and the spacing strips 46 have thus been
combined into a stack as shown in FIG. 20, the individual flat
pipes 44 are inserted into the recesses 56 of the stack which are
formed by the slots 43 and 47 either by being inserted laterally
through the open ends of these recesses or by being passed into the
latter from above. Due to the provision of the opposite grooves 6
in the lateral edges of the transverse slots 43 of rib plates 42
and due to the greater width b of the transverse slots 47 in the
spacing strips 46, narrow channels 57 are formed at both sides of
each pipe 44 which permit the pipes 44 to be embedded in the
casting metal 9 during the subsequent casting operation and will
then be filled out completely with this metal, whereby the
individual rib plates 42 will be likewise embedded in the casting
metal and firmly secured to the pipes 44. When the casting metal 9
has solidified, the entire row of spacing strips 46 on the
supporting ribs 52 of the assembling plate 51 is withdrawn by the
latter from the unit consisting of the pipes 44 and the rib plates
42.
When employing cardboard, asbestos sheets or the like, for
producing the spacing strips 46, these strips and the rib plates 42
are preferably punched out on separate machines both of which
operate at the same speed although their operations are offset at a
half cycle relative to each other so that by means of a combined
discharge device the punched rib plates 42 and spacing strips 46
may be automatically stacked on each other and fitted on the
supporting ribs 52 of the assembling plate 51.
If the spacing strips 46 consist of cardboard or the like the rib
plates 42 may also be properly aligned with each other in the
stacking process by employing an adhesive instead of mounting them
on an assembling plate 51. This adhesive should, however, have the
property that it loses its adhesive or binding power completely
when the liquid metal 9 has been cast into the stack, for example,
due to being heated by the liquid metal 9, so that when the casting
operation is completed and the casting metal 9 has cooled, the
spacing strips 46 may again be easily withdrawn from the rib plates
42.
FIGS. 21 to 24 show an embodiment of the invention which is
somewhat similar to that as shown in FIGS. 16, 17, 19 and 20 and is
especially suitable for the manufacture of an engine radiator for
an automobile. The individual parts of these two embodiments which
are similar to each other are designated by the same reference
numerals. Instead of employing separate spacing strips 46 as shown
in FIG. 18 which separate the adjacent rib plates 42 of the stack
from each other at a distance s and are removable after the casting
operation, this further embodiment of the invention is provided
with spacing tabs 58 of a dovetailed shape which are partly punched
out of the rib plates 42 in the manner as shown in FIGS. 21 and 24
and are bent over at right angles about the shorter edges 59 of the
tabs so that the outer cut edge 60 of each tab 58 abuts against the
shorter edge 59 of the adjacent rib plate 42 of the stack without
engaging into the aperture 61 of this adjacent plate, which is
formed by cutting out and bending over each tab 58.
In order to prevent the casting metal from penetrating into the
channels 62 between the adjacent rib plates 42, these rib plates 42
are bent closely adjacent to the edge portions 64 in which the
slots 43 are provided into which the flat pipes 44 are to be
inserted, so that the parts of each rib plate adjacent to the slots
43 have a z-shaped cross section, as shown in FIGS. 21 and 24. Of
course, instead of providing flat pipes 44 as shown in FIGS. 17 and
22, it is also possible to insert a plurality of parallel pipes of
a circular cross section into each slot 43 of the rib plates.
After the rib plates 42 are stamped out and bent as described and
their tabs 58 are also bent over, they may be stacked on each other
in the manner as shown in FIG. 24, so that the z-shaped parts 63
and also the tabs 58 of the adjacent rib plates support each other,
respectively. The inner sides of each pair of these z-shaped parts
63 which are separated by a slot 44 into which a flat pipe 44 or a
series of parallel pipes 65 are inserted then form an open casting
channel 66 through which the casting metal may be poured.
The operation of stacking the rib plates 42 so as to be in proper
alignment with each other may be carried out by the aid of a common
assembling plate 67, as shown in FIG. 23, which is provided with
projections 68 which engage into corresponding recesses 70 in the
edges 69 of the rib plates 42 and prevent the latter from shifting
relative to each other. If desired, this assembling plate 67 may
also be provided with casting channels (not shown) which
communicate with the casting channels 66 through which the liquid
metal may be cast into the latter. Since the material of the rib
plates 42 is very thin, it is advisable to support their z-shaped
webs 63 during the casting operation by filling out the channels 62
between the adjacent rib plates with fine sand which may again be
easily removed when the casting operation is completed.
If the adjacent rib plates 1 of the embodiments according to the
invention as illustrated in FIGS. 2 and 3 and 7 to 13 are to be
spaced at short distances from each other, the rib plates 1 may
likewise be provided with spacing tabs 58 similarly as described
with reference to FIGS. 21 and 24 and as indicated in dotted lines
in FIG. 1.
Although my invention has been illustrated and described with
reference to the preferred embodiment thereof, I wish to have it
understood that it is in no way limited to the details of such
embodiment but is capable of numerous modifications within the
scope of the appended claims.
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