FIELD OF THE INVENTION
The present invention relates in general to a system for avoiding coolant loss
occurring due to improper fitment of the radiator cap on the coolant- filled
radiators, and more particularly, to a system for ensuring proper fitment of the
radiator-cap prior to engine cranking.
BACKGROUND OF THE INVENTION
The function of the cooling system in the engine cooling device is to eliminate
excess heat produced by the engine to keep it working in its most efficient
temperature. This system also helps the engine get the proper temperature as
soon as possible right after the vehicle starts. And regardless of the operating
conditions, the cooling system maintains the engine at its most capable
temperature.
The cooling systems incorporate a coolant tank (coolant reservoir) storing the
coolant. Coolant is the combination of water and antifreeze flowing throughout
a liquid-cooling system, around the hot engine parts, to significantly get rid of
the heat as well as to prevent damage. The heat produced in the engine is acted
upon by the coolant and transported by the water pump through the radiator.
The air blowing through the radiator is responsible for cooling the coolant. The
radiator functions to provide a safe opening so that liquid or any other suitable
medium can be vented out and to maintain the desired system pressure.
Moreover, the coolant tank (coolant reservoir) is provided with a radiator cap
(with notches constructed on the side surfaces) which, when removed allows
the coolant tank to be refilled or checking coolant levels in the tank. While
putting back the cap in place, the likelihood of the radiator cap being not
tightened so that the radiator cap is in full tight position is high, thereby
leading to coolant loss, overheating of engine and eventually reducing the life of
the engine. Fig.1 shows different circumstances which might lead to improper
fitment of the radiator caps.

Thus, clearly it is not desirable to have the engine started in cases where the
radiator cap is not in full tight position or installed properly as to avoid leakage
of coolant from the coolant reservoir. There is a necessity to develop a
dedicated, simple and secured system for controlling the powering ON/OFF of
the self-starter solenoid of the engine based on the condition of proper fitment
of the radiator cap on neck of the coolant reservoir.
OBJECTS OF THE INVENTION
An object of the invention is to overcome the aforementioned and other
drawbacks existing in prior systems for ensuring proper fitment of the coolant
radiator cap.
Another object of the present invention is to develop a novel system for
controlling engine cranking based on tight position of a coolant radiator cap.
Yet another object of the present invention is to develop a novel system for
ensuring coolant loss due to improper fitment of the coolant radiator cap.
Still another object of the present invention is to develop a secured system for
controlling engine cranking based on tight position of a coolant radiator cap.
These and other objects and advantages of the present invention will be
apparent to those skilled in the art after a consideration of the following
detailed description taken in conjunction with the accompanying drawings in
which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION
The present application discloses a system for controlling an engine cranking
based on tight position of a coolant filled radiator cap 1. In an embodiment, the
system includes a coolant reservoir tank 10 for storing coolant, a coolant
radiator cap 1 with two notches 1A defined on side surfaces of the coolant
radiator cap 1. Further, the coolant radiator cap 1 is removably fixed on a neck
of the coolant reservoir tank 10. The system further includes a sensor 2 being

disposed in close proximity with the coolant radiator cap 1 for sensing position
of either of the notches 1A defined on the side surfaces of the coolant radiator
cap 1. Further, in an embodiment the sensor 2 (proximity sensor 2) generates
the output based on detection of either of the two notches 1A within a
detectable range of 15mm. Further, in an embodiment, the system includes a
cranking relay 3 configured to pick-up based on the generated output from
said sensor 2 and powering a self-starter solenoid 4 which is further configured
to crank the engine.
In another aspect, the present application discloses a method for controlling an
engine cranking based on tight position of a coolant filled radiator cap 1. The
method consists of locating a sensor 2 in close proximity with a coolant
radiator cap 1 which is removably fixed on a neck of a coolant reservoir tank
10. In an embodiment, the coolant radiator cap 1 has a plurality of notches 1A
defined on side surfaces of the coolant radiator cap 1. The method further
includes, powering the sensor 2 to sense position of a notch 1A among the
plurality of notches 1A defined on the side surfaces of the coolant radiator cap
1 and generating the output based on position of the notch 1A/tight position of
the coolant radiator cap 1. The method further includes connecting a cranking
relay 3 to self-starter solenoid 4 through a wired connection for cranking the
engine on generation of output from the sensor 2.
The above and additional advantages of the present invention will become
apparent to those skilled in the art from a reading of the following detailed
description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above brief description, as well as further objects, features and advantages,
of the present invention can be fully appreciated by reference to the following
detailed description. These features of the present invention will become more
apparent upon reference to the drawings, wherein:

Fig. 1 (1a-1f): Illustrates manual fitting and opening of a coolant radiator cap
and circumstances resulting in improper fitment of the coolant radiator cap.
Fig. 2: Illustrates a wired block diagram of a conventional system for cranking
the automotive engine.
Fig. 3: Illustrates a wired block diagram of a system configured to sense tight
position of the coolant radiator cap and control cranking of the automotive
engine according to an embodiment of the system.
Fig. 4: Illustrates a sensor positioned with respect to the coolant radiator cap
for accurately sensing the full tight position of the coolant radiator cap.
DETAILED DESCRIPTION OF THE INVENTION
Although the disclosure hereof is detailed and exact to enable those skilled in
the art to practice the invention, the physical embodiments herein disclosed
merely exemplify the invention which may be embodied in other specific
structure. While the preferred embodiment has been described, the details may
be changed without departing from the invention, which is defined by the
claims.
It will be apparent, however, to one of ordinary skill in the art that the present
invention may be practiced without specific details of the well known
components and techniques. Further specific numeric references should not be
interpreted as a literal sequential order. Thus, the specific details set forth are
merely exemplary. The specific details may be varied from and still be
contemplated to be within the spirit and scope of the present invention. The
features discussed in an embodiment may be implemented in another
embodiment.
Moreover, occasional references to the conventional techniques for controlling
the engine control system of automobiles are made in order to better
distinguish the present inventive disclosure discussed later in greater detail.

Few of the details pertaining to said techniques are well known in the art and
therefore, are described herein only in the detail required to fully disclose the
present invention while unnecessarily obscuring the present invention.
Improving upon and addressing the problems discussed at length above
(background), in the present disclosure an improved system for controlling
engine cranking based on sensing of the tight position of a coolant radiator cap
1 in Figs. 1, 3-4 clearly makes the improved engine cranking control system
present application advantageous over the existing arts (Fig. 2) as would also
become clearer to the knowledgeable in the art with the particulars of the
aforesaid unique configuration being described below in greater detail. The
present invention will be described in detail below with reference to
embodiments as shown in the drawings.
Turning now to the drawings, and referring first to Fig. 1, illustrates manual
fitting and opening of a coolant radiator cap 1 and circumstances resulting in
improper fitment of the coolant radiator cap 1. Fig.1a shows the ideal position
or the full tight position of the radiator cap 1. Further, Fig. 1b shows an
operator checking the level of coolant or coolant top by lifting the cap from the
neck of the reservoir 10. Furthermore, Fig.1c shows the opening of the
reservoir 10 after coolant top-up in case the level goes below the desired level.
Moreover, in Fig.1c depicts the operator putting back the cap after coolant level
checking or coolant top-up. While the operator is fitting back the radiator cap
1, there are times when the radiator cap 1 is not properly fitted leading to
coolant loss (Fig. 1f). In another case, the operator completely forgets to put
back the radiator cap 1 which is shown in Fig. 1c.
Fig. 2 illustrates a wired block diagram of a conventional system for cranking
the automotive engine. In order to start the engine by powering the self-starter
solenoid 4 the following elements are used conventionally in the configuration
as shown in Fig.2.

Battery (6): The supply to drive the whole electrical system is the battery 6. It
is most taxed during the starting of the engine. During this time it must supply
adequate voltage and amperage to not only run the starter but the starter
solenoid 4, relay 5, cranking relay 3, along with other support circuitry of
modern engines.
Cranking (Key Start) Switch: The cranking/starting relay 3 initiated by
tuning ON the cranking switch 7.
Cranking Relay: When the cranking relay 3 is energized by the starter switch
7 and radiator cap is in full tight position only then relay 5 points are closed
applying voltage to the self-starter solenoid 4, turning it on. All the starting
relay 3 does is turn the self-starter solenoid 4 on, since the proximity sensor is
only capable of carrying a small amperage load it turns on the relay 5 and the
relay 5 carries the load required to run the solenoid. In essence, the switch and
relay 5 are a pre-amp circuit for the self-starter solenoid 4.
Self-starter solenoid: The solenoid has a dual function; it acts a large high
current relay and engages the starter drive gear. When the magnetic field on
the solenoid is turned on by the starter relay the plunger on the solenoid
engages a large contact capable of carrying the amperage required to run the
starter motor. When the contacts come together the starter motor turns on and
the solenoid plunger pushes the drive gear into the starter ring gear allowing
the starter to turn the engine over.
Battery cables: The battery 6 cables are selected of a size and quality to carry
the load required during peak load conditions (starting the engine). The
selection of cable size and quality is well known in the art and hence not
discussed in further detail for the sake of brevity.
In operation (Fig.2), when key switch 8 is in ignition (ON) position, then it will
energize the battery cut off relay 9 (After energizing the battery cut off relay 9
power will flow through the circuit) and the battery 6 supplies the adequate

voltage and amperage to the cranking/starter relay 3. However, voltage will not
be supplied until relay 3 is closed. When cranking switch 7 is turns ON, the
cranking relay 3 will get energized and voltage will pass to the self- starter
solenoid 4, thereby cranking the engine by turning on the self-starter solenoid.
Further, in an embodiment, Fig.3 illustrates a wired block diagram of an
improved system configured to sense tight position of the coolant radiator cap
1 and control cranking of the automotive engine according to an embodiment of
the system. The improved system, in an embodiment implements a sensor 2
which in a preferred embodiment is a proximity sensor 2 positioned in
proximity to the target object which in the present case is a coolant radiator
cap 1. In an aspect, the coolant radiator cap 1 has two notches 1A constructed
as protrusions on the side surfaces (Fig.4). In another embodiment, the coolant
radiator cap 1 is positioned at a detectable range from the sensor’s 2 target
object i.e. the coolant radiator cap 1. Further, in an embodiment the detectable
range of the proximity sensor 2 is 15 mm (Fig.4).
Now as shown in Fig.3, in operation the proximity sensor 2 is powered by the
battery 6 when the switch 8 is in ON position. The proximity sensor 2 gets
powered up and detects the presence of either of the two notches 1A
constructed on the proximity sensor 2 at a detectable range of 15mm. On
detection of one of the two notches 1A in the 15mm range, the proximity sensor
2 gets magnetized and generates the output. In an embodiment, the generated
output voltage is 24 volts (mA amperage). In an embodiment, when the coolant
radiator cap 1 is made of metal, hence an inductive proximity sensor 2 is
preferred. In another embodiment, when the radiator cap 1 is made of plastic, a
capacitive or photoelectric type of proximity sensor 2 may be suitable for a
plastic target. In essence, the proximity sensor 2 generates the output when
the coolant radiator cap 1 is in full tight position. Further, the proximity sensor
2 is positioned in a manner as to generate the output only in the event one of
the two notches 1A is detected at distance of 15mm. Furthermore, the
proximity sensor 2 is positioned such that the coolant radiator cap 1 is in full
tight position if the notch 1A is detected within 15 mm distance. The proximity

sensor 2 provides an interlock for the system meaning that the starting relay 3
would not pick up if the proximity sensor 2 does not generate the output.
Further, in an aspect the output generated by the proximity sensor 2 energizes
the cranking relay 3 which in turn energizes the self-starter solenoid 4, thereby
turning on the starter motor. Further, in another aspect the output generated
by the proximity sensor 2 energizes a relay 3 connected between the cranking
relay 3 and the proximity sensor 2. The relay 5 is connected for protecting the
proximity sensor 2 from higher voltage and amperage and thus making it fault
probe in short life span. In another embodiment, the relay 5 also provides a
similar protection against high current to the proximity sensor 2.
For example, a proximity sensor 2 coupled engine cranking system is deployed
in cooling system of an excavator as shown in Fig.4 and proposed system
functions in the manner as discussed above at length. In a preferred
embodiment, the distance between the proximity sensor 2 and the sensor 2
metallic target (since the coolant radiator cap 1 in the coolant system of the
Excavator is made of metal) is so minimal as to avoid entry of any external
metallic element, thereby avoiding any fault detection by the proximity sensor
2.
Advantages
1. Preventing coolant loss.
2. Controlling the engine cranking system based on tight position of the
coolant radiator cap 1.
3. Prevent engine from overheating due to coolant loss.
The foregoing is considered as illustrative only of the principles of the
invention. Furthermore, since numerous modifications and changes will readily
occur to those skilled in the art, it is not desired to limit the invention to the
exact construction and operation shown and described. While the preferred
embodiment has been described, the details may be changed without departing
from the invention, which is defined by the claims.

WE CLAIM:
1. A system for controlling an engine cranking based on tight position of a
coolant filled radiator cap (1), said system comprising:
a coolant reservoir tank (10) for storing coolant;
a coolant radiator cap (1) with a plurality of notches (1A)
defined on side surfaces of the coolant radiator cap (1), said
coolant radiator cap (1) removably fixed on a neck of the coolant
reservoir tank (10);
a sensor (2) being disposed in close proximity with the
coolant radiator cap (1) for sensing position of a notch (1A) among
the plurality of notches (1A) defined on the side surfaces of the
coolant radiator cap (1) and generating output therein;
a cranking relay (3) configured to pick-up based on the
generated output from said sensor (2) and powering a self-starter
solenoid (4) further configured to crank the engine.
2. The system as claimed in claim 1, wherein the sensor (2) is a proximity
sensor (2).
3. The system as claimed in claim 1, wherein the sensor (2) is powered by a
battery (6) via a key-switch (8).
4. The system as claimed in claim 1, wherein a relay (5) is positioned on a
conducting path formed between the sensor (2) and the cranking relay (3)
for providing the relay (5) contact protection to the key-switch (8).
5. The system as claimed in claim 1, wherein the sensor (2) generates the
output when one of the notches (1A) is in a detectable range of the sensor
(2).
6. The system as claimed in claim 1 and 5, wherein the detectable range of
the proximity sensor (2) is 15 mm.

7. A method for controlling an engine cranking based on tight position of a
coolant filled radiator cap (1), the method comprising:
locating a sensor (2) in close proximity with a coolant
radiator cap (1) which is removably fixed on a neck of a coolant
reservoir tank (10), said coolant radiator cap (1) being defined with
a plurality of notches (1A) defined on side surfaces of the coolant
radiator cap (1);
powering the sensor (2) to sense position of a notch (1A)
among the plurality of notches (1A) defined on the side surfaces of
the coolant radiator cap (1) and generating output therein;
connecting a cranking relay (3) to self-starter solenoid (4)
through a wired connection for cranking the engine on generation
of output from the sensor (2).
8. The method as claimed in claim 1, wherein the senor (2) generates the
output when one of the notches (1A) is in a detectable range of the sensor
(2).
9. The method as claimed in claim 1, wherein the sensor (2) is a proximity
sensor (2).
10. The method as claimed in claim 1, wherein the sensor (2) generates the
output and the self-starter solenoid (4) is powered ON when the coolant
radiator cap (1) is in a full tight position.