DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
DIESEL ENGINE COMPARTMENT DOOR

Applicant:
Mazagon Dock Shipbuilders Limited
A company Incorporated in India under the Companies Act, 1956
Under Ministry of Defence,
(A Govt. of India Undertaking)
Having address:
Dockyard Road, Mazagon,
Mumbai - 400010, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] This patent application claims priority from Indian Provisional Application 201821043814 filed on November 21, 2018.

TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to an improvement in compartment door of a diesel engine pertaining to a marine vessel.

BACKGROUND
[003] Generally, diesel engine room of a marine vessel is isolated from a deck of the marine vessel by a compartment door. The compartment door of the marine vessel ensures complete sealing of the engine room from the deck of the marine vessel. Due to complete sealing of the engine room by the compartment door, the possibility of air entering the engine room is null. Further, the diesel engine will require large amount of air for combustion during full load running. Since, the engine room is an air tight enclosure, with no access to supply of fresh air, vacuum will be created in the engine room during full load running of the diesel engine. As vacuum is created in the engine room during full load running condition of the diesel engine, the compartment door may not open. Since, the compartment door cannot be opened in full load running condition of the diesel engine of the marine vessel, people on either side of the compartment door cannot communicate with each other. Hence, to open the compartment door of the diesel engine in full load running condition, enormous physical effort is required.

SUMMARY
[004] Before the present compartment door of diesel engine is described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a compartment door of diesel engine. The aspects are further elaborated below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[005] A diesel engine compartment door comprises a first wheel and a second wheel, a sheave pin, a spline shaft and a dowel pin. The sheave pin is configured with external multi-start threads with enhanced size. The dowel pin is configured to integrate the sheave pin and the spline shaft in to a single unit.

BRIEF DESCRIPTION OF THE DRAWINGS
[006] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawings:
[007] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[008] Figure 1A illustrates conventional compartment door of diesel engine of a marine vessel.
[009] Figure 1B illustrates sectional view of the compartment door of diesel engine of a marine vessel.
[0010] Figure 2A illustrates conventional spline shaft of the compartment door of diesel engine.
[0011] Figure 2B illustrates spline shaft of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter.
[0012] Figure 3A illustrates conventional sheave pin of the compartment door of diesel engine.
[0013] Figure 3B illustrates sheave pin of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter.
[0014] Figure 4A illustrates conventional threaded bush of the compartment door of diesel engine.
[0015] Figure 4B illustrates threaded bush of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter.
[0016] Figure 5A illustrates a conventional mounting bracket of the compartment door of the diesel engine.
[0017] Figure 5B illustrates a mounting bracket of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter.
[0018] Figure 6A illustrates a conventional support hub of the compartment door of diesel engine.
[0019] Figure 6B illustrates a support hub of the compartment door of diesel engine, in accordance with an embodiment of the present invention.
[0020] Figure 7A, 7B and 7C illustrates an assembled view of the compartment door of diesel engine of a marine vessel, in accordance with an embodiment of the present subject matter.
[0021] The figures depicts an embodiment of the present disclosure for purpose of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the object and method illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0022] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "generating,", “receiving”, "comprising,", “storing” and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems for generating a virtual representation of an object are now described. The disclosed embodiments for swiveling lifting lug are merely exemplary of the disclosure, which may be embodied in various forms.
[0023] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure for swiveling lifting lug is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0024] Generally, diesel engine room of a marine vessel is isolated from a deck of the marine vessel by a compartment door. The compartment door of the marine vessel ensures complete sealing of the engine room from the deck of the marine vessel. Due to complete sealing of the engine room by the compartment door, the possibility of air entering the engine room is null. Further, an air tight enclosure of the diesel engine room leads to generation of vacuum during full load running condition of the diesel engine. As vacuum is created in the engine room during full load running condition of the diesel engine, the compartment door may not open. Since, the compartment door cannot be opened in full load running condition of the diesel engine of the marine vessel, people on either side of the compartment door cannot communicate with each other. Hence, to open the compartment door of the diesel engine in full load running condition, enormous physical effort is required.
[0025] The present subject matter overcomes the above problems in the conventional compartment door of the diesel engine of the marine vessel. The present subject matter is designed to provide entry of air into the diesel engine room of the marine vessel. The present subject matter discloses compartment door of the diesel engine of the marine vessel designed to open completely during full load running condition of the diesel engine with less effort.
[0026] Referring now to figure 1, wherein the figure 1 discloses conventional compartment door of diesel engine of a marine vessel. The conventional compartment door of the diesel engine isolates the deck of the marine vessel from the engine room.
[0027] Figure 1B illustrates sectional view of the compartment door (1) of diesel engine of a marine vessel. Two wheels-a first wheel (2) and a second wheel (3) are located on either side of the compartment door. The first wheel (2) is mounted on a sheave pin (4). The sheave pin (4) further engages with a spline shaft (5). The spline shaft (5) has the second wheel (3) mounted on it. The sheave pin (4) and the spline shaft (5) are connected by a dowel pin (8). The dowel pin (8) integrates the sheave pin (4) and the spline shaft (5) into a single shaft unit. Thus, the rotation of the first wheel (2) results in rotation of the second wheel (3) and vice-versa. A mounting bracket (6) is placed below the second wheel (3) and above a support hub (7). The mounting bracket (6) and the support hub (7) enclose the spline shaft (5) and the sheave pin (4). The rotation of the first wheel (2) or the second wheel (3) translates into rotation of the single shaft unit. The mounting bracket (6) has a slot. Further, the spline shaft (5) enclosed inside the mounting bracket (6) meshes with a rack (9) through the slot in the mounting bracket (6). This engagement of the splines of the spline shaft (5) with the rack (9) enables movement of the rack (9). Furthermore, the movement of the rack (9) enables locking or unlocking of the diesel engine compartment door (1), in accordance with the direction of rotation of the wheels (2, 3). The thread size of threads on sheave pin (4) is increased hence the pitch of the threads of the sheave pin (4) is increased. Further, because of the increase in size of threads, the clearance between the external and internal meshing threads is increased which ensures increased flow of air from the outside of the engine room to the inside of the engine room. Thus, adequate amount of flow of air prevents vacuum formation inside the engine room.
[0028] Referring now to figure 2A, the figure illustrates conventional spline shaft of the compartment door of diesel engine. The conventional spline shaft of the compartment door of diesel engine has a length of 157 mm. The spline shaft is connected to a sheave pin by a dowel pin. Further, a wheel is mounted on the spline shaft. When the wheel is rotated, the splines of the spline shaft engage with the rack, thereby actuating the movement of the rack. The movement of the rack enables locking or unlocking of the door, in accordance with the direction of rotation of the wheel.
[0029] Referring now to figure 2B, the spline shaft (5) of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter. The length of the spline shaft is increased to 342.5 mm. The spline shaft is connected to a sheave pin by a dowel pin. Thus, the spline shaft and the sheave pin connected by the dowel pin forms an integrated shaft unit. The dowel pin enables easy maintenance of the integrated shaft assembly.
[0030] Referring now to figure 3A, wherein the figure 3A illustrates conventional sheave pin of the compartment door of diesel engine. The conventional sheave pin has double start threads. The pitch of the threads is less. Thus, the gap between the threads is less for the air to pass through it. Hence, the probability of air entering the engine room is less. Even, if air enters the engine room via the threads, the amount of air entering the engine room is negligible as compared to the amount of air used by the diesel engine during full load condition, thereby leading to vacuum in the engine room.
[0031] Referring now to figure 3B, wherein the figure 3B illustrates the sheave pin (4) of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter. The pitch of the threads of the sheave pin (4) is 40 mm. Thus, by increasing the pitch, the clearance between the internal and external meshing threads of the sheave pin (4) is increased. As the clearance between the external and internal meshing threads is increased, it enables entry of air from the outside of the diesel engine compartment to the engine room. Due to increased clearance between the engaging threads, the amount of air entering the engine room is more. An increased supply of fresh air into the engine room helps to prevent vacuum creation in the engine room that arises due to fast consumption of the fresh air by the diesel engine during full load condition. The sheave pin has multi-start threads (10). The sheave (4) pin has five start threads where the five start threads are acme threads. Further, the sheave pin (4) has a provision to accommodate a dowel pin (8) for integrating sheave pin (4) with the spline shaft (5).
[0032] Referring now to Figure 4A, which illustrates conventional threaded bush of the compartment door of diesel engine.
[0033] Referring now to Figure 4B, which illustrates threaded bush of the compartment door of diesel engine, in accordance with an embodiment of the present subject matter. The threaded bush has internal threads. The internal threads of the threaded bush mate with the threads of the sheave pin (4). Hence, the said threaded bush is configured to be mounted from the outer side of the door. The internal threads are also five start threads. Further, the pitch of the threads is 40 mm.
[0034] Referring now to Figure 5A, which illustrates a conventional mounting bracket of the compartment door of the diesel engine.
[0035] Referring now to Figure 5B, which illustrates a mounting bracket (6) of the compartment door of the diesel engine, in accordance with an embodiment of the present subject matter. The mounting bracket (6) is placed below the second wheel (3) of the door and rests on the support hub (7) wherein the support hub (7) is rigidly fixed on the fixed ribbed support fro the door . The mounting bracket (6) has a slot for permitting the rack (9) to engage with the spline of the spline shaft (5). The length of the mounting bracket (6) is increased to 170 mm. Further, the mounting bracket (6) is tapered along the length.
[0036] Referring now to Figure 6A, which illustrates a conventional support hub of the compartment door of diesel engine. The length of the support hub in conventional support hub is 52.5 mm.
[0037] Referring now to Figure 6B, which illustrates the support hub (7) of the compartment door of diesel engine, in accordance with an embodiment of the present invention. The length of the support hub (7) is increased to 97.5 mm. The support hub (7) is placed below the mounting bracket (6). The support hub (7) has slots across its length. The support hub (7) has holes at the top and bottom portion to engage with the holes of the mounting bracket (6) and the flange respectively. The said support hub (7) is fixed on the fixed ribbed support from the door.
[0038] Figure 7A, 7B and 7C illustrates an assembled view of the compartment door of diesel engine of a marine vessel, in accordance with an embodiment of the present subject matter.
[0039] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features.
[0040] Some embodiments of the compartment door of diesel engine reduces effort required to open the door during full load running condition of the diesel engine.
[0041] Some embodiments of the compartment door of diesel engine enables full opening of the compartment door of the diesel engine during full load running condition of the diesel engine.
[0042] Some embodiment of the compartment door of diesel engine can be employed in marine vessel. The marine vessel can be a submarine or a closed system vessel.
,CLAIMS:
1. A diesel engine compartment door (1) for marine vessel comprises:
a first wheel (2) and a second wheel (3);
a sheave pin (4) is configured with external multi-start threads (10) with enhanced size;
a spline shaft (5) in engagement with a rack (9) is configured to open or close the door locks through linkages provided on said rack (9) during rotation of the first wheel (2) or the second wheel (3);
a dowel pin (8), wherein the dowel pin (8) is configured to integrate the sheave pin (4) and the spline shaft (5) to form a single unit.

2. The diesel engine compartment door (1) as claimed in claim 1, wherein the first wheel (2) is mounted on the outer end of said sheave pin (4) and configured for opening said diesel engine compartment door(1) from outer side of the engine compartment.

3. The diesel engine compartment door (1) as claimed in claim 1, wherein the second wheel (3) is mounted on the spline shaft (5).

4. The diesel engine compartment door (1) as claimed in claim 1, wherein the multi-start threads of the sheave pin (4) are acme threads.

5. The diesel engine compartment door (1) as claimed in claim 4, wherein the pitch of the acme threads is 40 mm.

6. The diesel engine compartment door (1) as claimed in claim 5, wherein the acme thread is a five start thread.

7. The diesel engine compartment door (1) a claimed in claim 1, wherein said marine vessel is a closed system vessel or a submarine.

8. The diesel engine compartment door (1) a claimed in claim 1, wherein said diesel engine compartment door (1) is configured for providing predetermined air intake in the engine compartment during full load running of diesel engine.
9. The diesel engine compartment door (1) a claimed in claim 1, wherein said sheave pin (4) is configured with predetermined thread size to provide enhanced clearance between external and internal threads to increase air intake to abstain vacuum creation in said diesel engine compartment.

10. The diesel engine compartment door (1) a claimed in claim 1, wherein said sheave pin (4) is configured with multi-start threads (10) to provide enhanced air intake to abstain vacuum creation in said diesel engine compartment.