FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)
TITLE OF THE INVENTION Fail-safe engine stop arrangement
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. D R Katkar, Mr. R V Bhandari, Mr. D S Kulkarni
Mr. S V Purandare and Mr. N B Khandarkar
all are Indian nationals
of TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification describes the invention and the manner in which it is performed.

FIELD OF INVENTION
This invention deals with the engine stopping arrangement. More particularly, it deals with a dual means for engine stopping for single cylinder mechanically fuelled diesel engine. This system provides refined and robust engine stopping means.
BACKGROUND OF THE INVENTION
Engine stopping arrangement for engine comprises of a means of stopping fuel supply to the engine. Typically, mechanically fuelled single cylinder diesel engines make use of cable operated arrangement for engine stopping. The cable operates an engine stop lever which in turn stops the fuel supply to the engine, thereby stopping the engine. This arrangement which calls for the vehicle driver to perform an additional operation of pulling the engine stop lever for stopping the engine. Considerable amount of work has been done in the field of engine stop arrangements for single cylinder engines.
US patent 6404071 explains an engine stopping apparatus having a vehicle body 3 with an engine mounted therein; a transponder 5 to which information on identification of a driver has been inputted; a collating circuit for transmitting a collation signal to the transponder and for identifying the driver on the basis of a response signal with respect to the same; and a control circuit for controlling the driving of the engine on the basis of a result of collation by collating circuit, wherein the transponder 5 is arranged to be held in a state of being worn on a driver side separately from vehicle body 3.
US patent 4193385 explains an engine stopping device for stopping an internal combustion engine provided with an ignition system energized by a generator driven by the engine. The stopping device comprises a switch for making ineffective at least one of the elements of the ignition system, an actuator for actuating the switch into the operated state and a retaining device for retaining the

switch in the operated state until the engine is brought to a stand still. Although it takes time for the engines to be brought to a standstill, the operator just has to give the actuator one touch operation, such as pressing a button, and may release the actuator before the standstill. Subsequent starting of the engine requires no extra operation.
US patent 4971001 explains an improved engine shut-off system in which the likelihood of a safe failure is maximized and the likelihood of an unsafe failure is minimized. Both terminals of the engine's first stop switch are connected in the ignition circuit so that if either wire leading to a stop switch terminal is grounded or breaks, a fail-safe condition exists. A first terminal of the first stop switch is connected in circuit to the main coil's primary winding, and the second terminal is connected in circuit to either the control switch means or the trigger coil. An optional second stop switch may be used in conjunction with the first stop switch. The optional second stop switch may be a seat switch.
It is worthwhile to note at this all the above referred patents deal with spark ignited engines. In case of spark ignited engines the engine stopping arrangement works on ignition control method. In case of diesel engines the engine stopping is achieved through fuel cut-off method. Typically this is achieved through an electrical solenoid in case of multi cylinder engines. However, single cylinder engines pose further challenge that the engine tends to run for long time with the fuel leftover in the dead volume. The stopping arrangement for single cylinder engines comprises of an engine stop lever which is operated through cable manually. The present invention aims at providing an additional quick acting electrical system which is operated through ignition key and hence does not call for any additional manual operation. The arrangement also has a self return mechanism.

OBJECTS OF INVENTION
• The main object of this invention is to provide a dual stop arrangement for single cylinder diesel engine.
• Yet another object of this invention is to provide an engine stop arrangement which calls for minimum modifications in present engine configuration..
• Yet another object of this invention is to provide a dual engine stop arrangement wherein both the engine stop mechanisms can be actuated independently.
• Yet another object of this invention is to provide a dual engine stop arrangement that is fail-safe.
• Yet another object of the present invention is to provide a dual engine stop arrangement wherein one engine stop is mechanical and the other engine stop mechanism is electrical.
SUMMARY OF INVENTION
The present invention aims at providing an engine stopping system that combines both the automatic as well as manual engine stopping system. The automatic stopping is achieved through electrical arrangement, whereas the manual stopping is achieved through a cable operated system. The return springs of the system are incorporated in such a way that the system returns to normal (fail-safe position) in case of system malfunction for either of the systems. The dual engine stop arrangement comprises of following -
i) An engine stop lever
ii) A mechanical system for operating the engine stop lever
iii) An electrical system for operating the engine stop lever
iv) A return arrangement for engine stop lever The dual engine stop arrangement comprises of two independently actuating means of operating engine stop lever through two cables. One of these cables is operated manually & the second cable is operated through an electrical solenoid.

The arrangement of cables & springs is such that the two engine stop mechanisms can be actuated independently & in failsafe manner.
The return springs ensure that the engine stop lever returns to its normal position after the engine is stopped through one of the mechanisms. The arrangement of cables and springs is such that the two engine stop mechanisms actuate the engine stop lever independently in failsafe manner.
STATEMENT OF INVENTION
Accordingly the present invention discloses a fail-safe engine stop arrangement comprising at least one engine stop lever (11); at least one bracket (12) configured for accommodating linkage to facilitate the operating said engine stop lever (11) at least one mechanical system for operating the engine stop lever (11); at least one electrical system for operating the engine stop lever (11); and at least one return arrangement for engine stop lever (11) thereby constituting the dual engine stop arrangement with two independently actuating means of operating engine stop lever.
The bracket (12) is configured for accommodating two cables (13,14) working independent of each other for operating said fail-safe engine stop arrangement wherein one cable (13) is configured to be operated manually and the second cable (14) is configured to be operated electrically through an electrical solenoid (15).
The knob (16) is provided on both the cables to facilitate unidirectional movement of engine stop lever.
The return arrangement comprises of return springs configured for ensuring return of the engine stop lever (11) to its normal position after the engine is stopped through any of the mechanisms.

The return spring on the engine stop lever is configured to restore the original position of the engine stop lever (11).
The manually operated cable (13) is configured to be manually pushed back to its position.
The engine stop lever (11) is configured to twist in engine stop lever return spring in addition to compressing the return spring in the electrical solenoid (15) during electrical actuation. The solenoid is configured to be de-energized after a predetermined time.
The return spring in the solenoid is configured to restore the electrically operated cable (14) to return to its original position.
DESCRIPTION OF PREFFERED EMBODIMENTS
Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.
The sketches showing details of the arrangement of components for a dual engine
stop arrangement are shown here.
Fig. 1 shows the engine stop arrangement in accordance with the present invention
Fig. 2 shows the details of the engine stop lever in accordance with the present
invention
Fig. 1 shows the engine stop arrangement in accordance with the present invention. It comprises of an engine stop lever (11) & bracket (12) which are designed to accommodate the. two cables for operating it. Out of these two cables one cable (13) is operated manually and the second cable (14) is operated electrically through an electrical solenoid (15). The manually operated cable (13) and electrically operated cable (14) work independent of each other. When either of the cables is pulled, the engine stop lever is operated & the engine is stopped. The knob (16) is

provided for both the cables in such a way that, the engine stop lever can be moved only in one direction and while returning the engine stop lever & the cable return to their respective position separately. Due to counterclockwise movement of the engine stop lever (due to pulling either of the cable) the return spring on of the engine stop lever is twisted which helps in restoring the original position of the lever. The manually operated cable (13) is pushed back to is position manually. If the engine stop lever is pulled electrically then, in addition to the abovementioned twist in engine stop lever return spring, the return spring in the electrical solenoid (15) is compressed. After a predetermined duration of time (typically ~ 6 sec) the solenoid is de-energized and the return spring in the solenoid also helps the electrically operated cable (14) to return to its original position.
Fig. 2 shows the schematic details of modified engine stop lever (11). It has two holes (21) & (22). Hole (21) is used for manually operated cable whereas hole (22) is used for electrically operated cable.
The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

WE CLAIM
1. A Fail-safe engine stop arrangement comprising
at least one engine stop lever (11);
at least one bracket (12) configured for accommodating linkage to facilitate operation of said engine stop lever (11)
at least one mechanical system for operating the engine stop lever (11);
at least one electrical system for operating the engine stop lever (11); and
at least one return arrangement for engine stop lever (11) thereby constituting a dual engine stop arrangement with two independently actuating means of operating the engine stop lever.
2. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said bracket (12) is configured for accommodating two cables (13, 14) working independent of each other for operating said Fail-safe engine stop arrangement, wherein cable (13) is configured to be operated manually and the cable (14) is configured to be operated electrically through an electrical solenoid (15).
3. The Fail-safe engine stop arrangement as claimed in claim 1, wherein a knob (16) is provided on both the cables to facilitate unidirectional movement of engine stop lever (11).
4. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said return arrangement comprises of return springs configured to ensure return of the engine stop lever (11) to its normal position after the engine is stopped.
5. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said return spring on the engine stop lever is configured to restore the original position of the engine stop lever (11).

6. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said manually operated cable (13) is configured to be manually pushed back to its position.
7. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said engine stop lever (11) is configured to twist in engine stop lever return spring in addition to compressing the return spring in the electrical solenoid (15) during electrical actuation.
8. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said solenoid is configured to be deenergised after a predetermined duration of time.
9. The Fail-safe engine stop arrangement as claimed in claim 1, wherein said return spring in the solenoid is configured to restore the electrically operated cable (14) to return to its original position.