FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION FINNED TUBE RADIATOR CORE
2. APPLICANT(S) MAHINDRA & MAHINDRA LTD.
GATEWAY BUILDING, APOLLO BUNDER, MUMBAI - 400001, MAHARASHTRA, INDIAN.
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates generally to a radiator used with motor vehicles such as tractors and like, and particularly, to a radiator core having incorporated with plurality of fluid conducting means such as tubes which are adapted to design with finned outer surface to increase cooling surface area thereby to obviate need of separate fins, and disposed in a specific way to sustain performance of said radiator core equally with that of conventional radiator while eliminating problems associated with conventional radiator core such as core choking, premature tube failure, etc.
BACKGROUND OF THE INVENTION
In tractors or similar off-road vehicles provided with water cooled engine, radiator is an essential part of the cooling system. Main functional parts of radiator are inlet tank, core, outlet tank, cowl (shroud), mounting frame and coolant recovery tank. The inlet tank has an inlet port for entry of hot engine coolant, a coolant top-up port fitted with a cap, which has a built-in pressure valve. Radiator core has multiple rows of tubes made of thin sections of aluminium in case of aluminium core radiator, or copper in case of copper-brass core radiator, to carry coolant from inlet tank to outlet tank. In an aluminium core radiator, there are corrugated fins made of thin sheets of aluminium in between tubes. In a copper-brass core radiator the fins are made of thin sheets of brass and arranged in parallel direction. The cowl is located in such a way that its center fairly matches with that of the core. Design of radiator is quite complex as it has to be based on input parameters like engine horse power, air flow rate, coolant flow rate for optimal coolant carrying capacity and effective heat dissipation.

Radiator core consists of one or more rows of fluid conducting means such as tubes, typically of capsule shape cross section or circular cross section made of thin aluminium sheet. Between adjacent tubes, lies a corrugated fin, which is also made from thin aluminium sheet. When engine is running, hot coolant from engine travels to radiator inlet tank through hoses and piping. From inlet tank, coolant enters into radiator core. A radiator fan (driven by engine or electrical power) draws surrounding atmospheric air through radiator core. As the coolant passes through radiator core, heat of coolant is transferred mainly by fins and partly by tubes of radiator core by convection to air drawn by radiator fan. Thus coolant of reduced temperature reaches from core to outlet tank of radiator and gets re-circulated back to engine.
Conventional radiator used in off-road vehicles such as tractors has following field problems:
> Choking of radiator core due to entrapment of trash or similar matters present in surrounding atmosphere. This problem occurs, especially in field operations like threshing, because of very less space between tubes and fins for air flow, in spite of provision of radiator trash guard or tractor front grille with very fine holes. The core choking reduces heat dissipation capacity of radiator, which results in engine overheating. If engine overheats for a prolonged period then it may result in engine-seizure.
> It is tedious process to clean choked radiator core because of very tight space between fins and tubes, and also because of the danger of damage to the tubes or fins, which are very delicate to handle during cleaning. Core choking takes place in spite of provision of a trash guard and a tractor grille with very fine holes. Moreover, trash guard and tractor grille with fine holes increase resistance to air flow and reduce air flow rate for a particular speed of radiator fan, which eventually results in load on the

fan to draw air and hence excess fuel consumption for the same amount of air drawn.
> Leakage of coolant through core tube - This happens because the tubes are made of very thin sheets, in which holes get formed due to thermal stress, corrosion, erosion and cavitations. In case of a radiator with aluminium core, tube cannot be repaired or serviced; hence the entire radiator needs to be replaced at cost.
> Deformation or damage of core fins in transit or handling. It cannot be repaired. If deformed fins are not detected and the radiator is not replaced, it reduces effective cooling surface area and hence reduces heat dissipation capacity of radiator.
> Undesirable early clogging of core tubes due to very narrow coolant passage area and presence of dirt, fine metal particles or similar impurities in engine coolant, resulting in decreased cooling efficiency.
There has been quite some work done in the area of radiator itself and in othe, external means associated with radiator to obviate afore mentioned problems. Some of them are described hereunder for reference.
US Patent 1363416 discloses a method of making spirally corrugated tubes in which the radiator which is incorporated with such tubes may be considered to solve aforementioned problems. However, the design of corrugation provided on the surface of the tube not being sufficient enough to increase cooling surface area, may not get better performance of the cooling system of the engine.
Hence the present invention is designed with the objective of effectively eliminating all the above mentioned problems by providing a radiator with

innovative radiator core assembly, which is easy to manufacture with less complexity, and disposed in radiator without compromising on heat dissipation capacity of radiator, or without necessity of change in overall mounting arrangement of radiator, or without necessity of change in other parts or accessories of the cooling system.
OBJECTIVES OF THE INVENTION
The present invention overcomes the shortcomings associated with the background art and achieves other advantages not realized by the background art.
The main objective of the present invention is to provide a radiator core having plurality of fluid conducting means such as tubes which are adapted to design with finned outer surface to increase cooling surface area thereby to obviate need of separate fins.
Another objective of the present invention is to provide a radiator core having plurality of fluid conducting means such as tubes which are disposed in a specific way to avoid entrapment of trash and sustain performance of radiator core equally with that of conventional radiator even in absence of conventional separate fins.
Yet Another objective of the present invention is to provide a radiator core having plurality of fluid conducting means such as tubes which are disposed in a specific way to make the radiator core efficient in engine cooling and for allowing minimum air pressure drop across its core, that further results in less power and fuel consumption by radiator fan.
Yet another objective of the present invention is to provide a radiator core with higher volume flow rate of coolant, which imposes less back pressure on

coolant pump that further results in less power and fuel consumed in driving coolant pump.
Yet another objective of the present invention is to provide a radiator core which can be cleaned easily without causing damage to the radiator core, if choked by trash or similar matters present in surrounding atmosphere.
Yet another objective of the present invention is to provide a radiator core with additional semi circular cooling surface area on tubes at both front and rear end of core.
Yet another objective of the present invention is to obviate necessity of additional arrangements and components in vehicle to shield the radiator core for preventing core choking.
Yet another objective of the present invention is to avoid necessity of very small openings in front grille of vehicle and thereby to reduce power and fuel consumed in driving radiator fan for drawing specific amount of air.
Yet another objective of the present invention is to provide a radiator core which can be readily accommodated in the radiator without necessity of change in radiator design or related parts thereof.
According to one aspect of the present invention, the radiator core comprises an inlet tank, an outlet tank, a plurality of fluid conducting means, frame and a plurality of plate, wherein said plurality of fluid conducting means are designed with finned outer surface and provided with a fluid passage of single cross section throughout the length thereof, said finned surface is wavy and annular in shape and having crest portions and valley portions. First end of the fluid conducting means is the end with extended crest portion having length equal to half of the pitch dimension, whereas second end is cut at the peak point of

the crest portion. The frame is formed with structural plates, the inlet tank and the outlet tank in which both the inlet tank and the outlet tank are fluidly connected with each other. The plurality of plate are provided with holes of size same as or larger than the cross section of the fluid passage of the fluid conducting means and horizontally mounted with other two side structural plates of the frame of the radiator core at equal intervals.
According to another aspect of the present invention, the radiator core is disposed with the fluid conducting means in such a way to effect flow of engine coolant with the help of gravity, wherein the first end and the second end of the fluid conducting means are alternatively mounted in a same plane of the plurality of plates so as to bring plurality of crest portion of one fluid conducting means in front of plurality of valley portion of an adjacent fluid conducting means , to ensure sufficient and uniform transverse space at any plane between any two adjacent fluid conducting means which in turn ensures least trash entrapment at any location of the radiator core assembly and effective cooling of engine coolant.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS:
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are

given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is front elevation of radiator incorporating radiator core assembly of the present invention;
FIG. 2 is side elevation of the radiator shown in FIG.l;
FIG. 3 is top elevation of the radiator shown in FIG.l and FIG.2;
FIG. 4 is front elevation of fluid conducting means which is disposed in the core of the radiator according to the present invention;
FIG. 5 is enlarged view of the portion X of radiator core indicated in FIG.l;
FIG. 6 is enlarged view of the portion Y of radiator core indicated in FIG.l.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiments in many different forms, the drawings and detail description of specific embodiments shown here and the present disclosure is to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. In the description below, like reference numerals are used to describe the same, similar or corresponding parts in the several views of FIG 1- 6.
Referring to FIG.l, a radiator describing the present invention is being designated as numeral 1 and shows complete assembly of radiator including the present invention. A typical radiator comprises an inlet tank 5 and an outlet tank 6, both joined to a core assembly 16 by suitable joining means sc

that all joints are leak proof at specified working pressure and temperature of engine radiator coolant. As shown in FIG.2, an inlet pipe 7 and an outlet pipe 8 are fluidly connected to the inlet tank 5 and the outlet tank 6 respectively. An inlet hose (not shown in figure) is connected to the inlet pipe 7, and an outlet hose (not shown in figure) is connected to the outlet pipe 8. Shroud (cowl) 9 is a conventional part, at the center of which is mounted a radiator fan (not shown in figure). An opening 4 is provided at top of the inlet tank 5 for filling coolant and a radiator cap 2 is used for tightly closing the opening 4. An outlet port 3 provided on the opening 4 for fluidly connecting with a siphoning tube (not shown in figure). The other end of the siphoning tube is connected to a coolant recovery tank (not shown in figure).
The radiator core assembly 16 is being described with referring to FIG.l and FIG.2. According to the present invention, the core assembly 16 comprises a plurality of fluid conducting means 17, frame 10 and a plurality of plate 18. Said plurality of fluid conducting means 17 are designed with a finned outer surface and provided with a fluid passage of single cross section throughout the length thereof. The frame 10 includes first, second, third and fourth structural plates designated as 19, 20, 21 and 22 respectively. The first structural plate 19 is integrated with the inlet tank 5, and the second structural plate 20 is integrated with the outlet tank 6. The plurality of plates 18 which are sufficiently wide and provided with holes of size same as the cross section of the fluid passage 11 of the fluid conducting means 17 to provide for fluid passage between the rows of fluid conducting means, and are horizontally mounted with third and fourth structural plates 21 and 22 of the frame 10 of the radiator core assembly 16 at equal intervals between first and second structural plates 19 and 20 of the frame 10. The plurality of fluid conducting means 17 are arranged vertically between the plates 18 and the first & second structural plates 19 and 20. The plates 18, the fluid conducting means 17 and the structural plates 19, 20, 21, 22 are joined by suitable

joining means thereby to ensure joints are leak proof at specified working pressure and temperature of engine radiator coolant.
With reference to FIG.4, the plurality of fluid conducting means 17 according to the present invention is being described in detail herein below. The fluid conducting means 17 is a homogeneous part that can be made of aluminium or copper or brass or similar metal which is having good characteristics of hea*: conduction. The fluid passage 11 provided at the center of the fluid conducting means 17 is used for circulating hot coolant coming out from engine. The finned surface is wavy and annular in shape and having a plurality of crest portion 15 and a plurality of valley portion 14 as shown in FIG.4. First end 13 of the fluid conducting means 17 is the end with extended crest portion 23 having length equal to half of the pitch dimension, whereas second end 12 is cut at peak portion of another crest portion 15. Sufficient width is provided between the inner passage surface and the valley portion 14 so as to ensure reliability of the fluid conducting means 17.
The arrangement of the fluid conducting means 17 in accordance with the preferred embodiment of the present invention is described with reference to FIG. 1, FIG.5 & FIG.6. FIG.5 and FIG.6 show enlarged view of section indicated as X and Y in FIG.1 FIG.5 shows that there is provided sufficient minimum transverse space between fourth structural plate 22 and adjacent fluid conducting means 17 at any plane. This ensures sufficient gap hence least trash entrapment at any location of the core assembly 16. FIG.6 shows that the plurality of fluid conducting means 17 are arranged in such a way that the first end 13 and the second end 12 of the fluid conducting means 17 are alternatively mounted in same plane of the plates 18 so as to ensure uniform and sufficient minimum transverse space at any plane between any two adjacent fluid conducting means 17 which in turn ensures no trash entrapment at any location of core assembly 16. Pitch dimension of the finned surface of the fluid conducting means 17 is optimized to ensure maximum heat

dissipation from hot coolant to air with minimal air pressure drop across the radiator core 16 according to the present invention.
The process of heat transfer between the hot coolant and ambient air according to the aforementioned constructional details of the present invention is described in herein below. Water pump forces hot coolant through inlet hose and inlet pipe 7 to the inlet tank 5. From the inlet tank 5, the coolant flows through the fluid passages 11 of the fluid conducting means 17 disposed in the radiator core 16. As the coolant flows through the core 16, the heat energy contained in the hot coolant is dissipated by convection through the plurality of fluid conducting means 17 of the core 16 to atmospheric air drawn by radiator fan. Thus the heat extracted coolant enters Into the outlet tank 6 and goes back to engine though the outlet pipe 8 and the outlet hose.
It will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed in the foregoing description. Accordingly, the particular embodiments described in detail herein are illustrative only and are not limiting to the scope of the invention, which is to be given the full breadth of the appended claims and any all equivalents thereof.

We claim:
1) A radiator core incorporated in a radiator used for off road vehicles
comprising:
a plurality of fluid conducting means for carrying coolant from an inlet tank to an outlet tank;
a plurality of plates disposed substantially in parallel to both the inlet tank and the outlet tank to support said plurality of fluid conducting means;
wherein said plurality of fluid conducting means is an elongated tube having provided with finned surface on its outer side to increase surface area thereof, which In turn increases heat transfer rate of the coolant that passes therethrough.
2) The radiator core as claimed in claim 1, wherein the finned outer surface of the plurality of fluid conducting means is formed with plurality of crest and valley shapes.
3) The radiator core as claimed in claim 1, wherein the plurality of fluid conducting means is made of homogeneous material.
4) The radiator core as claimed in claim 1, wherein the plurality of fluid conducting means is provided with a fluid passage of single cross section along the central axis thereof.

5) The radiator core as claimed in claim 4, wherein cross section of the plurality of fluid conducting means is of capsule shape.
6) A radiator core assembly incorporated with a radiator used for off road vehicles comprising:
an inlet tank for receiving coolant that carries heat from internal combustion engine;
an outlet tank for receiving coolant from the inlet tank and then pumping to the internal combustion engine;
a plurality of fluid conducting means for carrying coolant from the inlet tank to the outlet tank;
a plurality of plates disposed in parallel to both the inlet tank and the outlet tank to support said plurality of fluid conducting means;
wherein said plurality of fluid conducting means is an elongated tube having provided with finned surface at the outer periphery to increase surface area thereof, which in turn increases heat transfer rate of coolant that passes therethrough;
wherein the finned outer surface of the plurality of fluid conducting means formed with plurality of crest and valley;
wherein a first end of the fluid conducting means is formed with extended crest portion having length equal to half of pitch dimension of the finned surface, whereas a second end is cut along peak point of another crest portion; and

wherein the plurality of fluid conducting means is substantially vertically arranged between the inlet tank and the outlet tank in such a manner that the first end and the second end of the fluid conducting means are alternatively mounted in a same plane of the plurality of plates so as to bring plurality of crest portion of one fluid conducting means in front of plurality of valley portion of an adjacent fluid conducting means, to ensure sufficient and uniform transverse space at any plane between any two adjacent fluid conducting means.