Vehicle radiator and method of making

A radiator core is combined with upper and lower tanks which tanks are each a welded combination of tube walls and a header plate which receives the tubes of the radiator core.

This invention relates to a novel combined tank and header plate for 
radiator cores, a novel method of making such a combined tank and plate, a 
novel radiator using the combined tank and header plate and a novel method 
of making said radiator. 
The art to which the invention relates is that of radiators designed 
principally for installation at the front of a truck or other vehicle for 
cooling the coolant fluid of the engine. The radiators with which the 
invention is concerned comprise a core, upper and lower tanks and members 
joining the upper and lower tanks to provide the necessary structural 
strength for the radiator during use. The terms `upper` and `lower` herein 
refer to a common orientation for the radiator but are not intended to be 
limiting in either the disclosure or claims since the radiator may have 
any orientation. The structural members preferably connect to the upper 
and lower tanks at connections exterior to the tanks and to the core. The 
core with which the invention is concerned is composed of generally 
parallel tubes for carrying coolant fluid, linked by cooling fins, 
extending transverse to the core. The core alone preferably forms a 
self-sustaining assembly before the radiator is assembled although such 
assembly, even if self-sustaining, will require structural support during 
use in the radiator. The core with which the invention is concerned 
provides upper and lower tube ends projecting above and below, 
respectively, the uppermost and lowermost transverse fins. Upper and lower 
header plates are each apertured to receive the tube ends and designed 
with the tubes, to make sealing connection therewith. The header plates 
may, in prior designs alternatively, be considered as part of the core or 
as the core-adjacent walls of the upper and lower tank. Applicant's U.S. 
Pat. No. 4,756,361 ('361 hereafter) dated Jul. 12, 1988 and entitled 
Radiator Core shows a radiator core of which the header plate forms a 
part. The disclosure of such patent is included herein by reference. 
However in patent '361 the header plate is first attached to the core 
before attachment to the side walls and core remote wall of the tank. In 
accord with this invention a header plate is first attached to the side 
and core-remote walls of the tank to form a combined tank and header plate 
before attachment of the core to the header plate. 
As in patent '361 the preferred header plate in this invention is apertured 
to receive the adjacent tube ends. In accordance with an important aspect 
of the invention, a resilient centrally apertured grommet is placed in 
each header plate aperture and dimensioned together with the header 
aperture so that the grommet is compressed on tube insertion to provide 
good sealing between the grommet and the tube outside walls and between an 
outer surface of the grommet and the header plate. The sealed arrangement 
thus provided leaves the tube in communication with the inside of the 
header tank. 
It should be noted that in the broader aspects of the invention the welded 
combined tank and header plate-may be combined with a wide variety of 
cores, not limited to the type of patent '361 and the sealing of tank and 
tube will be determined by the type of core and header plate used. It 
should be noted that the core preferred is that of patent '361 and the 
sealing of tubes to header plates is preferably performed using the 
resilient grommets described in patent '361. However where grommets are 
used, the header plates, apertures and grommets need not be circular, in 
distinction to patent '361 although the round shape is preferred. The 
grommets preferred herein have a more rounded contour on the interior side 
than those shown in patent '361 to facilitate their insertion in header 
plate apertures from the outside of a completed tank. 
In accord with the method of the invention, the upper and lower tanks are 
formed of blanks which are welded together to form a sub-assembly being 
the side and core-remote walls of a tank and which define an opening 
facing the intended assembly direction of the core. The necessary fittings 
and connections may then be welded to the sub-assembly with outside welds. 
The term `side walls` includes either the longer side walls or sides and 
the shorter side walls or ends. The core-remote wall may have a defined 
division from the side walls or both may be part of a continually curving 
surface. The term `sub-assembly` is not intended to imply an order to the 
welding processes used herein. Thus where the sub-assembly is composed of 
welded panels it is not necessary that the sub-assembly welding be 
complete before the header plate is welded to the side walls. 
Alternatively the side wall panels or some of them could be welded to the 
header plate before the core-remote wall or other walls are welded to side 
panels. The welds should be on the outside of the tank to permit easy 
welding repair of leaks. 
In the broad aspects of the inventive method the apertured header plates 
are selected for sealing connection to the tubes of the radiator core, so 
that the outside of the tube may later be sealed to the header plate while 
the inside of the tube will at that time be in communication with the 
inside of the tank. The header plate thus selected is welded to the side 
walls of the sub-assembly to form, with the side assembly a combined tank 
and header plate. 
After welding is completed, in upper and lower combined tanks and header 
plates, the tanks are assembled above and below the core with the outsides 
of the tubes sealed to the header plates and the insides of the tube in 
communication with the insides of the tanks. 
In a preferred aspect of the inventive method the core is formed in accord 
with patent '361. A header plate is provided designed to receive grommets 
as described in patent '361 although the preferred grommet shape shown 
herein is an improvement over that shown in patent '361. In distinction to 
patent '361 however the header plate is herein welded to the tank side 
walls before assembly to the core and before insertion of the grommets. In 
accord with the preferred method of the invention, after the welding is 
complete the grommets are inserted in the header plate apertures and the 
tanks are assembled to the core by inserting the tubes in the grommets of 
the upper and lower tanks. The grommets are dimensioned to be compressed 
and sealed to the header plates and sealed to the tubes. The assembled 
tanks and core are provided with means connecting the upper and lower 
tanks to rigidify the radiator. The core before assembly is preferably a 
self-sustaining unit although it requires structural support in use. Side 
members are attached to Join the upper and lower tanks to provide the 
structural rigidity for the radiator and the core. 
In U.K. patent 29,777 of W. S. Tyler dated 27 DEC 12 a radiator is 
disclosed wherein the upper and lower tanks are provided with grommets for 
sealing relationship with individual tubes bowed and inserted in the 
grommets to extend between the upper and lower tanks. However the upper 
and lower tanks are cast which would be a practical impossibility since 
each tank model would require a separate mold and a manufacturer or repair 
shop of modest size would have to have about 150 different molds to 
provide radiators or replace tanks for current vehicle models. Moreover 
the tubes are not interconnected by fins and require individual 
installation. The individually replaceable tubes would render repair of 
the Tyler unit impractical. Further the fins and tubes do not exist as a 
separate core unit. By contrast; in the inventive method, the tanks and 
header pate are easily formed and welded as a unit and the change of 
dimensions from one model to the next is easily taken into account when 
the sub-assembly or header plate blanks are stamped and the blank 
production is amenable to computer assisted manufacturing techniques. 
Moreover the core comprising vertical tubes with horizontal fins joining 
them may be prefabricated as a separate assembly as taught in patent '361 
for assembly with the upper and lower tanks and side rails as when 
required. 
The inventive method may further be contrasted with some present methods of 
fabricating tanks which stamp the shape of the core-remote and side walls. 
Here again such present methods would require about 150 stamping forms. 
Moreover the preferred inventive method using the grommets for sealing 
avoids the complexity and size increase caused by the present methods 
which attach the header plate by a bolt, and gasket or soldered 
construction. 
In an alternative aspect of the inventive method a vehicle having a damaged 
radiator core but upper and lower tanks may have its radiator replaced by 
cutting off the tanks adjacent the header wall, providing header plates of 
the first type described in patent '361 first welding the header plates to 
the tanks, inserting grommets and assemble the combined tanks and header 
plates thus formed with a core. 
In accord with another aspect of the invention the invention provides a 
sub-assemblies of welded blanks forming the side and core remote walls of 
a tank, welded to a header plate to which grommets may be applied which 
may be fitted to the tube ends at each end of the core. 
In accord with the invention there is provided a combined radiator tank and 
header plate comprising the side and core-remote walls of a pre-existing 
radiator welded to a header plate designed to receive grommets for, in 
turn, receipt of the tubes of the pre-assembled core. 
In accord with the matters discussed above the objects and consequent 
advantages include: 
It is an object of the invention to provide a combined tank and header 
plate and a radiator made therefrom and method of making the combination 
and the radiator, which are economical and convenient to manufacture. 
It is an object of the invention to provide a combined tank and header 
plate and a radiator made therefrom and method of making which allows for 
use where size restrictions inhibit contemporary bolt and gasket 
techniques for joining the header plate to the tank. 
It is an object of the invention to provide a radiator and method, of 
construction which is readily disassembled for core repair or cleaning. 
It is an object of the invention to provide a combined tank and header 
plate, radiator made therefrom and method of making which allow the use of 
the side and core-remote walls of a pre-existing tank to be used with a 
welded to a header plate as described. 
It is an object of this invention to provide a combined tank and header 
plate with a simplified construction which eleminates the use of soldered 
Joints or bolt and gasket construction. 
The combined tank and header plate may be constructed of any weldable metal 
but will usually be of steel, brass or aluminum. It is understood that 
members to be welded together must both be of the same metal. 
Other advantages and features of the invention will be described in 
connection with the specific embodiment.

In the drawings FIG. 3 shows a blank 10 which is stamped to provide panels 
for a header plate 12 and the longer side walls 14 of a radiator tank. The 
header plate will be stamped with apertures 16 to accept grommets, (as 
hereafter described and as described in patent '361), apertures 18 for 
such fittings as hose connections and end flanges. Apertures 16 will be 
arranged in an array to correspond to the tube arrangement in the core. 
The blank's dimensions and the location and dimensions of the apertures 
may conveniently be provided by automated machinery under computer 
numerical control (`CNC`) and generally in accord with computer assisted 
manufacture (`CAM`) or design (`CAD`). 
As shown in solid lines 20 the corners of the blank are preferably cut 
along diagonals relative to the length and width axes of the blank 10 and 
for a purpose to be hereafter discussed. 
The blank 10 comprises the header plate 12 (centrally) and, on each side, 
side walls 14 which are folded as indicated by arrow 24 to form the longer 
side walls of the combined tank and header plate. The folding may be 
performed by conventional machinery well known to those skilled in the 
art. 
A blank 26 is provided with a central panel 28 of length corresponding to 
the longitudinally extending edges 30 and 32 of sides 14 and a width 
corresponding to the distance between said edges 30 and 32 in the folded 
position of blank 10. Blank 26 provides outer panels 34 and 36 of common 
width with panel 28 and length corresponding to the diagonals 20 of blank 
10. 
The blank 26 is then folded by conventional machinery to, the form shown in 
FIG. 3 conform to the upper (in folded form) edges 30 and 32 of the walls 
14. Any necessary fittings and connections may then be welded to the 
folded blank 10 with outside welds. 
End plates 38 and 40 are designed to form the short side walls of the tank 
to extend between side wall end edges 42 and extends upwardly above the 
end edge 44 of the walls 14 and end edge 44 to form a panel 46. 
The upper panel 46 of the end plates 38 is provided with end apertures 48 
for a purpose to be described hereafter. The sloping edges of the top wall 
and the upstanding panel 48 of the end plates form a niche 50 to receive 
bolts 52 (FIG. 1) extending through hole 48 and the nuts 54 on the inner 
end. 
Thus the folded form of the header plate 12 and longer side walls 14 is 
welded with outside welds 56 to the top plate and the end plates welded in 
place with outside welds 58. There is thus shown a combined upper header 
plate and tank 60. Lower header plate and tank 62 is formed in a similar 
in manner and is usually identical to tank 60. 
All welding in the fabrication of the tank is performed before the grommets 
are inserted. The preferred arrangement of having a blank comprising the 
header plate 16 between the two longer side walls 14 provides rigidity 
along the folded lines 15 both before and after welding to the other tank 
components. Moreover the (outside) welding 56 along edges 30, 32 at the 
maximum distance from the grommets 66. Thus if leaks develop in this area 
in a fabricated radiator in use, remedial exterior welding to stop the 
leaks is at the maximum distance from the (relatively) heat sensitive 
grommets, avoiding damage to the grommets. 
Although the blank arrangement shown is preferred the sub-assembly (within 
the broad scope of the invention, may be made up of exteriorly welded 
blanks as desired. Or the header plated may be exteriorly welded to one or 
more blanks making up part of the sub-assembly before the exterior welding 
thereto of the blanks of the sub-assembly. 
The lower tank will be formed in the same manner as the upper and 
preferably is identical thereto. Grommets 64 are provided for insertion in 
the apertures of the header plates. 
The resilient grommet 66 is shown in FIG. 4 which is a section along the 
axis of revolution of the grommet which is a surface of revolution. As 
shown, the grommet defines a groove 67 dimensioned to receive the aperture 
16 defining edges of header plate 12. The relative dimensions are such 
that the grommet when installed will press on each side of plate 12. The 
groove 67 is defined by upper lip 68 and lower lip 70. The lower lip 70 is 
nearly rectilinear in section with a slight fairing to the root of the 
groove. The upper lip 68 is rounded at the outside to be almost 
semicircular in section. This may be compared with the grommets shown in 
patent '361. In the patent '361 both upper and lower lips are rectilinear 
in section. This former grommet shape although useful before and useful 
with this invention, has some tendency to tear on insertion and is more 
difficult to use where all the work of insertion must be done from one 
side of the header plate as with this invention. Thus the grommet with the 
rounded upper lip 68 is preferred. The `upper` lip 68 of course becomes 
the lower for insertion downwardly into the header plate of the lower 
tank. 
The grommets 66 are dimensioned, in relation to the diameters of the 
apertures 16 and of the core tubes 74 so that, with the grommet in the 
aperture and the tube 74 passing through the aperture in the grommet, the 
grommet is compressed between the aperture defining edges of header plate 
12 and the outside surfaces of tubes 74 to seal with both header plate 12 
and tubes 74. 
Preferably this is achieved by making the unstressed diameter of the root 
of groove 67 slightly larger than the diameter of the header plate 
aperture and the unstressed diameter of the groove aperture slightly 
smaller than the exterior diameter of a tube 74. 
The grommets 66 are of resilient material selected to maintain the 
resiliency and strength of the grommets under the necessary condition of 
heat and cold which will be encountered by the radiator in use. It is 
preferred to use silicone and of the silicone materials available I prefer 
to use 60 Durometer manufactured by Freudenberg-NOK Inc. P.O. Box 100, 65 
Spruce St., Tillsonburg Ont. CANADA N4G 4H3. The choice of grommet 
qualities is constrained to materials yieldable enough to allow tube 
insertion and resilient enough to seal against the tube walls and header 
plate edges. Silicone is very much preferred to rubber which is much more 
subject to deterioration and cracking under the range of temperature 
conditions. The grommets 66 are preferably made in the form of a surface 
of revolution where the apertures 16 are circular. 
Grommets 66 are preferably constructed so that the groove 67 is slightly 
narrower than the thickness of the header plate 12. The result is that 
when the grommet is first inserted in an aperture 16 it is slightly 
concave upward and downward. These concavities tend to become flat when 
the tube is inserted. This does not materially affect the sealing which is 
principally between the aperture defining edges of the header plate and 
the root of the groove. 
After completion of the fabrication of the tanks, 60 and 62 the grommets 66 
are pressed into place in the header plate apertures, from the outside of 
the tank, with the rounded (section) lip 68 entering the tank for 
cooperation with the inside surface of the header tank and the rectilinear 
(section) lip 70 resting on the outside surface of the plate. 
Side rails 78 are rectangular U shaped channels apertured at 80 top and 
bottom for bolting by bolts 52 to the upper and lower tanks after assembly 
of the core, a bolt 52 passing through an aperture 80 and than aperture 48 
of a welded tank. 
The construction of the core will not be described in detail but reference 
may be made to Patent '361 for a full description. 
Briefly the core comprises an array of vertically extending tubes 74 of 
thermal conducting material, preferably: copper, brass, aluminum or steel 
and fins 82 or 84 which extend between the tubes and transversely thereto. 
I prefer to have each fin extend the width of the core but they may 
encompass a number of rows from front to tear. In the embodiment shown, 
copper fins 82 encompass the rearward four transverse rows of tubes 74. 
Steel fins 84 extend across the forward row of tubes. The steel fins are 
less efficient in their cooling function but are much stronger and harder 
than the copper fins and protect the latter from flying stone or other 
particles in use of the radiator on a vehicle. 
As described in patent '361 the fins are apertured to slidably receive the 
tubes. In stamping the apertures upwardly standing collars 86 are 
provided. The collars 86 act as spacers between the fins. 
Again, as described in patent '361, for core assembly the fins are arranged 
in a rack or stand in the desired relationship for the core. The tubes are 
then slid through the fins to their desired positions with tube ends 74E 
projecting above and below the uppermost and lowermost fins, respectively. 
With fins and tubes in place, tools, described in patent '361 are used to 
expand the tubes into functional engagement with the fins and thermal 
connection with the fin apertures and collars. The core is now, 
preferably, a (frail) self supporting assembly for connection to the 
tanks. Although self supporting for assembly purposes the core must be 
supported in actual use--as hereinafter described, by a frame comprising 
the upper and lower tanks 60 and 62 and side rails 78. 
With supporting means which are conventional and well known to those 
skilled in the art, the lower tank 62 is maintained in place. The tube 
ends 74E will have been peened in as shown at 88 to taper slightly for 
ease of insertion in the fins. The tube ends 74E for ease of insertion in 
the grommets 66 are first covered with a lubricant (for example liquid 
dish-washing detergent) then pressed into the lower header plate grommets 
60 preferably until the lower fin 82 or 84 contacts the grommet. The 
resilient grommet is dimensioned to be compressed between the tube and the 
aperture edges to make a good seal with the exterior tube and with the 
header plate. It is noted that the inside of the tube is now in 
communication with the inside of the tank. 
The core, with lower tube ends 74E inserted in the lower header plate is 
supported on any of a number of conventional manners while the upper tank 
and header plate is lowered over the upwardly extending tube ends 74E 
lubricated and dimensioned to form with the grommets 66 a seal as 
discussed in connection with the assembly of the core to the lower tank 
and header plate. 
With upper and lower tanks connected to the header plate, the three 
elements are supported in any conventional manner while the side frames 78 
are bolted in place. A rigid structure is then formed. The holes 88 on the 
uprights of the U-shaped side rails are then used for mounting the 
radiator in a vehicle and the connections made to the upper and lower 
tanks. 
There is thus provided a combined radiator tank and header plate which is 
easily fabricated to 150 or more combinations of height depth and width 
dimensions, which is easily assembled and dissassembled to the core and 
side rails and which with its combined tank and header plate and grommets 
dispenses in two ways with the soldered or bolt and gasket. assemblies of 
the prior art. Firstly the arrangement dispenses with soldering of the 
tube exterior to the header plate (as discussed in patent '361). Secondly 
soldering or gaskets is dispensed with between header plate and tank side 
walls as disclosed herein. 
The tank side and top walls may be assembled with welded panels in a 
different configuration than that shown. However the preferred arrangement 
which provide the longer side walls in a single blank with the header 
plate and folded upwardly therefrom, has advantages. The weld line is 
necessarily along the upper edges of the longer side walls, well spaced 
from the grommets on the header plate. Thus in case of leaks, occurring 
during fabrication, the exterior welds may be perfected, sufficiently far 
from the grommets to avoid damage from the heat. The arrangement described 
also provides fold lines 15 on the blank, running in the long dimension of 
the member to supply structural stability prior to and after the welding 
into a tank. 
Another aspect of the invention is the provision of upper and lower 
combined tanks and header plates in repair of existing tanks (FIG. 6). The 
existing tanks are detached from the vehicle and cut at line 90 at a 
location conform to the selected dimensions of the core. 
A header plate 92 similar to panel 12 is welded from the outside to each of 
the upper and lower tanks (only the upper tank 94 is shown) thus forming a 
combination tank and header plate from the side and core-remote walls of 
an existing tank 94 and a new header plate 92. 
After, the welding of the upper and lower combined tanks and header plates 
is completed grommets 66 are inserted round lip first in the header plate 
apertures as previously described. 
The upper and lower tanks assembled to the core as previously described in 
connection with the embodiment of FIGS. 1-5. Side frames joining the upper 
and lower tanks in a rigid structure may be provided of a character 
determined by the prior tank structure of the vehicle being repaired. In 
this aspect of the invention it will be noted that there is some 
flexibility in vertical dimension. Thus given the dimensions of the 
pre-existing tank, the core and two tank heights provided must combine to 
total the available height for the particular vehicle. However the tanks 
may be cut deeper or shallower and the core made taller or shorter within 
the available height limits and designed to provide the desired relation 
the volume of the tanks and the height of the core. 
FIG. 8 shows an alternative form of the invention where the side plates 14A 
have right angled corners in distinction to edges 20 of FIG. 3. The side 
plates 14A where they overlap niche 50 above wall 34 are provided with 
apertures 48A. Side rails 78A are again of rectilinear cross-section but 
the rails are dimensioned to slide over the side walls 14A of the tank. 
The uprights 106 are provided with apertures 80A so that attaching bolts 
may be inserted through apertures 80A and 48A with nuts to bolt the 
members together. Apertures 80A and 48 are located so that end edges 42A 
of walls 14A are `snug` to the inside corners 107 to form a rigid 
structure when the bolting is complete. End wall 38A may in this 
alternative be welded between walls 14A. 
As with the embodiment of FIGS. 1-5 the panels of the tank and the header 
plate are first welded with outside welds. The lower tank is similiarly 
constructed. Grommets are then placed in the header plate apertures. The 
upper and lower tanks are then bolted in place. 
There is minimal width advantage by reversing the channel from its 
orientation shown in FIG. 1 since although the core may be made wider, the 
outer areas of the core will be covered by the side panels of the side 
rails. 
In FIG. 7 there is shown a header plate 104 with welded peripheral side 
walls 106 for welding to a pre-existing tank 94. Although only a shorter 
side wall 106 is shown similar peripheral longer side walls are provided 
and welded to the tank 94 at exterior welds 108. 
All embodiments described assume a circular core tube in a grommet which is 
a surface of revolution in turn in circular apertures on a header plate. 
However the invention, in its broad aspects, may be used with a core 
having (as known in the prior art) eliptical or oval tubes or tube ends. 
The header apertures of a combined tank and header plate in accord with 
the invention are similarly shaped as will be the grommets which may be 
molded to the desired shape, while maintaining the outward groove and 
dimensioned to compress in use to seal to the header plate and to the tube 
exterior. 
Without intending to limit the scope of the invention I prefer to construct 
the combined tank and header plate of steel for economy and I have used 
steel thickness of between 0.119" and 0.134". Other weldable metals may 
obviously be used at an added cost. For example where, in accord with the 
alternative schematically demonstrated in FIG. 6, the existing tank was 
brass, I have welded thereto a brass header plate 92 of thickness 0.060".