Claims:1. An air pressure vent valve assembly for preventing increase of air pressure in an operator cabin or interior compartment of an automotive vehicle comprising :
? at least one flap for opening and closing the air pressure vent valve assembly;
? at least one vent plate mounted on an outer panel of the operator cabin or interior compartment for forming tight seal between the flap and the vent plate;
? at least one fastening means for mounting the vent plate on the outer panel of the operator cabin or interior compartment;
? at least one fastening means for mounting the flap on the vent plate;
? at least one nut washer for tightening the flap from the other side so that the flap may not detach from the fastening means; and
? at least one door or window for opening and closing an entrance of the operator cabin or interior compartment.
2. The air pressure vent valve assembly claimed in claim 1, wherein the flap gets open and closed based on air pressure difference between air pressure inside the operator cabin or interior compartment and the ambient air pressure of the outer atmosphere.
3. The air pressure vent valve assembly claimed in claim 1, wherein the flap gets open when air pressure inside the operator cabin or interior compartment exceed to a pre-determined air pressure value.
4. The air pressure vent valve assembly claimed in claim 1, wherein vent plate is mounted on the outer panel of the operator cabin or interior compartment by fastening means.
5. The air pressure vent valve assembly claimed in claim 1, wherein the flap is mounted on the vent plate and fastened thereon by means on fastening means.
6. The air pressure vent valve assembly claimed in claim 5, wherein the flap is further tightened other side by means of the nut washer so that the flap may not detach from the fastening means.
7. The air pressure vent valve assembly claimed in claim 1, wherein the flap normally or originally placed in the closed position and remain in closed position until the air pressure of the operator cabin or interior compartment is exceed the pre-determined air pressure value .
8. The air pressure vent valve assembly claimed in claim 1, wherein the flap is made up from rubber, plastic or any other material.
9. The flap is made up from such material claimed in claim 8, wherein the flexibility, resilience and stiffness of flap material is such that the flap get opened when air pressure of the operator cabin or interior compartment is exceed the pre-determined air pressure value.
10. The air pressure vent valve assembly claimed in claim 1, wherein the flap may reside either on the inner or the outer surface of the vent plate.
11. The air pressure vent valve assembly claimed in claim 1, wherein vent plate is mounted on either inner or outer side of the outer panel of the operator cabin or interior compartment.
12. The air pressure vent valve assembly claimed in claim 1, wherein the flap may be in either round, square, rectangular, oval or any other geometric shape.
13. An air pressure vent valve assembly for preventing increase of air pressure in an operator cabin or interior compartment of an automotive vehicle comprising :
? at least one air filter unit for filtering external fresh air and introducing it in the operator cabin ;
? at least one suction box for introducing filtered fresh air into the operator cabin or the interior compartment;
? at least one blower for suction and circulation the filtered fresh air introduced through the air filter unit inside the suction box;
? at least one outer duct for connecting and transferring the filtered fresh air to the blower and further to the suction box ;
? at least one bond structure to form ;
? at least one hose for connecting the bond structure and the outer duct ;
? at least one flap for opening and closing the air pressure vent valve assembly;
? at least one vent plate mounted on an outer panel of the operator cabin or interior compartment for forming tight seal between the flap and the vent plate;
? at least one fastening means for mounting the vent plate on the outer panel of the operator cabin or interior compartment;
? at least one fastening means for mounting the flap on the vent plate;
? at least one nut washer for tightening the flap from the other side so that the flap may not detach from the fastening means; and
? at least one door or window for opening and closing an entrance of the operator cabin or interior compartment.
14. The air pressure vent valve assembly claimed in claim 13, wherein the blower starts working the external fresh air suctioned towards the suction box through the outer duct and a low pressure area created in the outer duct.
15. The air pressure vent valve assembly claimed in claim 13, wherein as the blower starts working the low pressure area created in the bond structure and the hose which further keeps the flap in the close position.
16. The air pressure vent valve assembly claimed in claim 13, wherein the blower starts working the external fresh air suctioned towards the suction box and a low pressure area created in the outer duct.
17. The air pressure vent valve assembly claimed in claim 13, wherein one end of bond structure connected to the hose while other end is connected to the vent plate.
18. The air pressure vent valve assembly claimed in claim 13, wherein blower starts working and suction created into the bond structures which further pulls the flap towards the vent plate and forms tight seal.
19. The air pressure vent valve assembly claimed in claim 13, wherein the flap is in closed or original position when the blower is non-working condition.
20. The air pressure vent valve assembly claimed in claim 13, wherein the flap gets open and closed based on air pressure difference between air pressure inside the operator cabin or interior compartment and the ambient air pressure of the outer atmosphere.
21. The air pressure vent valve assembly claimed in claim 13, wherein the flap gets open when air pressure inside the operator cabin or interior compartment exceed to a pre-determined air pressure value.
22. The air pressure vent valve assembly claimed in claim 13, wherein vent plate is mounted on the outer panel of the operator cabin or interior compartment by fastening means.
23. The air pressure vent valve assembly claimed in claim 13, wherein the flap is mounted on the vent plate and fastened thereon by means on fastening means.
24. The air pressure vent valve assembly claimed in claim 23, wherein the flap is further tightened other side by means of the nut washer so that the flap may not detach from the fastening means.
25. The air pressure vent valve assembly claimed in claim 13, wherein the flap normally or originally placed in the closed position and remain in closed position until the air pressure of the operator cabin or interior compartment is exceed the pre-determined air pressure value .
26. The air pressure vent valve assembly claimed in claim 13, wherein the flap is made up from rubber, plastic or any other material.
27. The flap is made up from such material claimed in claim 26, wherein the flexibility, resilience and stiffness of flap material is such that the flap get opened when air pressure of the operator cabin or interior compartment is exceed the pre-determined air pressure value.
28. The air pressure vent valve assembly claimed in claim 13, wherein the flap may reside either on the inner or the outer surface of the vent plate.
29. The air pressure vent valve assembly claimed in claim 13, wherein vent plate is mounted on either inner or outer side of the outer panel of the operator cabin or interior compartment.
30. The air pressure vent valve assembly claimed in claim 13, wherein the flap may be in either round, square, rectangular, oval or any other geometric shape.
31. The air pressure vent valve assembly claimed in claim 13, wherein the opening is provided in the centre of flap for providing entrance to the fastening means to tighten the flap.
32. The air pressure vent valve assembly claimed in claim 13, wherein the multiple bond structures connected with each other through a duct which creates equal pressure inside the bond structures.
33. The air pressure vent valve assembly claimed in claim 13, wherein flap is provided with at least one opening of round or any other geometric shape on the periphery aligning with the shape bond structure.
34. The air pressure vent valve assembly claimed in claim 13, wherein flap is provided with multiple diaphragms which get opened when pressure of inside the operator cabin or interior compartment exceeds the pre-determined air pressure value.
, Description:FIELD OF THE INVENTION
The present invention relates to an automotive vehicle, off-road vehicle, earthmoving vehicle and particularly a vent valve mechanism for an operator cabin or an interior compartment of an off-road vehicle, construction, earthmoving vehicle such as tractor, wheel loader, excavator, compaction machine etc. to allow reducing the air pressure rise inside the cabin and more particularly to design and development of vent valve to prevent air pressure rise inside the interior compartment or the operator cabin due to opening and closing of the operator cabin door or window.

BACKGROUND OF THE INVENTION
A typical automotive vehicle includes a mechanism for preventing increase of air pressure between the interior compartment of the automotive vehicle and the outside atmosphere. The interior compartment of the automotive vehicle or operator cabin is generally provided with air conditioning system for providing a comfortable environment to operator and passengers.
A modern operator cabin of off-road and/or earthmoving, construction vehicles such as tractor, excavator, wheel loader, compaction machine etc. is provided with positive pressured interior compartment to avoid dust ingress. The operator cabin of such vehicle provided with HVAC system which is capable of providing heating and cooling environment by sucking fresh filtered air from outside atmosphere and to raise and maintain interior air pressure between 50 Pa to 200 Pa.
Generally the operator cabin or interior compartment of vehicle is effectively sealed from outside environment to provide good heating and air conditioning system inside the vehicle compartment. During certain circumstances like closing of door or window of interior compartment, it has been observed that air pressure inside the interior compartment of the automotive vehicle or operator cabin is more compared to outside ambient atmospheric pressure.
During such conditions the operator or occupant has to put strong efforts to close the door or window of cabin or interior compartment because of high interior air pressure. This problem is most severe with the sealed cabin intend to be pressurized by the ventilation system to provide positive internal pressure to prevent dust ingress. It has been also observed that the door or window often remain in semi-closed or semi-opened position. The operator or occupant cannot keep door in semi-closed position as it may dangerous to them and it is also against the regulatory norms. Moreover high sound generated, if the operator put strong efforts to the door or window. It leads to create serious effects on health of the operator as he may suffer from problems like air paining.
Common efforts were made to solve abovementioned problem and have been incorporated in construction of vehicles. A typical solution is mounting of cabin air pressure release valve which will allow to release air from the interior compartment to outside atmosphere whenever air pressure inside the interior compartment exceed to a predetermined air pressure value.
One of solutions of to solve above-mentioned problem is disclosed on patent publication no. JP2003246214. The air outlet unit includes a body having vent holes formed therein and each vent hole is provided with pivotal rubber or plastic flap. According to ‘214, the flap is hinged on body over vent hole which is normally in closed condition whenever air pressure inside the interior compartment exceed to a predetermined air pressure value, the flap gets opened towards outside direction.
However, the abovementioned solution has many drawbacks. First, opening and closing of the flap is solely controlled by using gravity and hence it has to be always in vertical orientation. It is not possible to keep flap in closed position when it require being due to vehicle movement, vibration and other reasons.
Second, in such cases, it is difficult to maintain positive pressure inside the vehicle’s compartment.
Third, the flaps make noises when they open or close and may be audible to the operator or occupants.
Forth, as size of such air outlet unit increases the amount of vehicle noise and noise of outside environment entering interior compartment also increases.
Another solution for the problem mentioned in patent publication no. US2013095738. The patent no. ‘738 discloses an air extractor system which includes diaphragm seat attached to panel of the vehicle’s interior. The diaphragm is moved between closed and open position with the help of spring or solenoid. As interior compartment air pressure is increases due to closing of door or window or any other reason then the diaphragm seat may be opened by using solenoid and sensing mechanism or any other means.
The abovementioned air extractor system, it is necessary to provide sensing mechanism to detect opening or closing of door or window. It is also necessary to provide solenoid or spring operated valve mechanism to open or closing the diaphragm seat.
Moreover, the construction of the said air extractor system requires solenoid valve and sensing mechanism thus it is complex in nature and expensive.
To overcome abovementioned shortcoming and problems associated with conventional system, it is more desirable to have air pressure vent valve assembly which is simple in construction, effective and cost effective than previously known methods and solves or at least relieves some of the problems discussed above.
It is therefore an object of the present invention is to overcome one or more problems associated with the prior art.
Another object of the present invention is to develop simple and effective an air pressure vent valve assembly for a vehicle.
Yet another object of the present invention is to develop automatically controlled opening and closing of an air pressure vent valve assembly for a vehicle.
Yet another object of the present invention is to utilize the low air pressure created between the blower and air filter unit in the outer duct for closing the flap of an air pressure vent valve assembly.
One more object of present invention is to develop an air pressure vent valve assembly which is user friendly and cost effective.
Yet another object of present invention is design the flap and provide the flap material resilience such that it get open and closed when the interior compartment air pressure exceed and lower the pre-determined pressure value respectively.
A method according to an aspect of the present invention is also disclosed.
Further advantageous embodiments and further advantages of the invention emerge from the detailed description below.
SUMMARY OF THE INVENTION
The present invention relates to an air pressure vent valve assembly for a vehicle. A preferred embodiment of the air pressure vent valve assembly includes at least one valve plate and at least one flap made from a flexible and resilient material so that when the flap is in closed position a tight seal is formed between valve plate and flap. The air pressure vent valve assembly is mounted on panel of the operator cabin or interior compartment which separate the interior compartment from the outside atmosphere. The valve plate has inner and outer surface and the flap may reside either on the inner or the outer surface depending upon the embodiment of the invention.
The air pressure vent valve assembly constructed in such manners that flap remain closed when the interior compartment air pressure is less than the pre-determined pressure value. The flap design and flap material resilience provided such that when the interior compartment air pressure exceed the pre-determined pressure value, the flap gets flex and open the vent valve assembly to permit a flow of air out of the operator cabin or interior compartment.
An alternate embodiment of the present invention comprises at least one flap, at least one bond structure and vent plate mounted on panel of operator cabin or interior compartment. The flap made from a flexible and resilient material so that when flap is in closed position a tight seal is formed between bond structure valve plate and flap. The air pressure vent valve assembly is connected to outer duct placed between air filer unit and blower through a hose.
The blower is used for introducing fresh clean air into the operator cabin or the interior compartment for creating positive air pressure inside the operator cabin or the interior compartment.
When the blower is in working condition and fresh air is introducing into the operator cabin and the low pressure area is created between the blower and air filter unit in the outer duct. The outer duct and the air pressure vent valve assembly is connected by using the hose which keeps the flap is close position to valve plate with the assistance of low air pressure created between the blower and air filter unit in the outer duct.
When the blower is in non-working condition in operator cabin, there will no low pressure area created between the blower and air filter unit in the outer duct. In such condition the flap will be in closed condition and but will not form as tight sealing with the vent valve due to creation of the low air pressure in the outer duct as described hereinabove.
In such case, the high air pressure created inside the interior compartment due to closing door or window of the interior compartment may be released to outer atmosphere through the hose. In such case the flap will be in open condition.
Other advantages and features of the present invention will become apparent when viewed in light of detailed description of the preferred embodiment when taken in conjunction with the drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the following drawings, a more detailed description of different exemplary embodiments of the invention will follow below.
In the drawings:
Figure 1 Illustrates side view of a construction or earthmoving machine;
Figure 2 Illustrates prospective view of an operator cabin of a construction or earthmoving machine;
Figure 3A Illustrates an air pressure vent valve assembly at closed position according to the preferred embodiment of the present invention;
Figure 3B Illustrates the air pressure vent valve assembly at open position according to the preferred embodiment of the present invention;
Figure 4 Illustrates the air pressure vent valve assembly connected to the outer duct and is at closed position when blower unit is in working condition and low air pressure is created in the outer duct according to the alternate preferred embodiment of the present invention;
Figure 5 Illustrates construction and design of the air pressure vent valve assembly according to the alternate preferred embodiment of the present invention; and
Figure 6 Illustrates configurations and design of the flap of the air pressure vent valve assembly according to the alternate preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
An air pressure vent valve assembly for preventing increase of air pressure in interior compartment of the automotive vehicle according to preferred embodiment of the present invention will be described hereinunder with reference to accompanying drawings FIGS. 1 to 7.
As shown in FIG. 1, a construction or earthmoving machine such as an excavator 100.
The construction or earthmoving machine an excavator 100 may be machine incorporating an air pressure vent valve assembly for preventing increase of air pressure in interior compartment; however embodiments of present invention are not restricted to machine depicted in FIG.1. The concept and other embodiments of the present invention may be used in other types of machine and machine illustrated in FIG.1 is merely shown as an example.
The construction or earthmoving machine 100 consisting of an operator cabin 11, actuating means 12, self-propelled crawler 13, working element or working implement 14, arm or boom structure 15, an engine 16, counter weight 17 and a revolving frame 18.
The said operator cabin 11 is mounted on said self-propelled crawler 13. The upper body of machine which includes the operator cabin 11, the engine 16, the counter weight 17, the actuating means 12, the working element or working implement 14 and the arm or boom structure 15 may be revolving in 360 degree with respect to the self-propelled crawler 13 with the assistance of the revolving frame 18.
There may be multiple numbers of wheels mounted on single or multiple axles instead of the self-propelled crawler 13. The self-propelled crawler 13 is driven by said engine 16. The said working element or working implement such as bucket or any other element 14 is attached to arm or boom structure 15 through pivot joint. The said actuating means 12 are working on hydraulic mechanism and there may be multiple actuating means located at multiple locations. The said actuating means 12 are critical part of machine and it may be used for performing various hydraulic operations through the construction or earthmoving machine 10. There may be multiple said working elements or working implement 14 attached to the construction or earthmoving machine 100. The operator cabin 11 is located at front side of the engine 16 while the counter weight 17 is located at rear side of the engine.
Referring to FIG. 2, the operator cabin of a construction or earthmoving machine is shown. The typical operator cabin 200 includes a door 213, an operator seat 212, operation levers 211, and an outer panel of cabin 214. A window arrangement may be provided for the operator cabin. The modern operator cabin 200 having tight sealing mechanism as it has been provided with air condition and ventilation systems.
Referring to FIGS. 3A and 3B, one of the preferred embodiments of the present invention the air pressure vent valve assembly at closed position and open position respectively. The air pressure vent valve assembly opened and closed based on air pressure difference between air pressure inside the operator cabin or interior compartment and the ambient air pressure of the outer atmosphere.
As shown in FIG. 3A and 3B, the air pressure vent valve assembly 300 is mounted on the outer panel 315 of the operator cabin or interior compartment. The air pressure vent valve assembly 300 comprises a flap 311, a vent plate 310, a valve screw 312, a nut washer 313 and a mounting screw 314.
The air pressure vent valve assembly 300 arranged in such way that the flap 311 is placed over the vent plate 310 with the help of fastening means such as valve screw 312 and further it is tightened by using nut washer 313. The vent plate is mounted on the outer panel 315 of the operator cabin by fastening means such as mounting screw 314 as shown on FIGS. 3A and 3B.
In the sealed operator cabin or interior compartment, it needs to put strong efforts to close the door or window of the operator cabin or interior compartment because of high interior air pressure since there is no outlet to release air pressure into the outer atmosphere. This problem has been solved by the air pressure vent valve assembly 300 according to the present invention.
The flap 311 is made from such material that when flap is in closed position a tight seal is formed between valve plate and flap. The flap 311 is made from such material that the flexibility, resilience and stiffness of flap material is such that the flap get opened when air pressure of the operator cabin or interior compartment is more than certain pre-determined air pressure value. As the air pressure of the operator cabin is exceed the certain pre-determined air pressure value, the flap 311 get pushed outside hence valve get opened as shown in FIG. 3B.
The air pressure vent valve assembly 300 constructed in such manners that flap 311 remain closed when the operator cabin or interior compartment air pressure is less than the pre-determined pressure value. The flap design and flap material resilience provided such that when the interior compartment air pressure exceed the pre-determined pressure value, the flap 311 gets flex and open the vent valve assembly to permit a flow of air out of the operator cabin or interior compartment.
The vent plate 310 has inner and outer surface and the flap 311 may reside either on the inner or the outer surface depending upon the embodiment of the invention.
The vent plate 310 may be mounted either inner or outer side of the panel 315 of the operator cabin or interior compartment. The vent plate 310 is mounted on the panel of the operator cabin or interior compartment by means of at least one fastening means such as mounting screw 314. The fastening means 314 may be fitted to the operator cabin or interior compartment panel 315 from the inside or outside depending upon design and mounting of vent plate 310.
The said flap 311 is made up from rubber or plastic or any other material and generally is in circular shape. However it is noted that the illustrated circular shape of flap merely shown as an example and is not intended to be limiting other shapes such as rectangular, oval, square etc.
The flap 311 is mounted on the vent plate 310 by any type of fastening means and as shown in FIG. 3A and 3B the flap 311 is mounted by valve screw 312 merely as an example and it is not intended to be limiting thereto. The flap 311 further may be tightened from the 313, so that the flap 311 may not detached from the valve screw 312.
In the sealed operator cabin as the door or window (not shown in FIG.), the air pressure inside the operator cabin or interior compartment get increased. If the pressure of inside the operator cabin or interior compartment exceeds certain pre-determined air pressure value then the flap 311 automatically get opened. The flexibility or resilience of flap material is such that it moves when air pressure inside the operator cabin or interior compartment exceeds certain pre-determined air pressure value.
When the air pressure inside the operator cabin or interior compartment become less than certain pre-determined air pressure value then the flap 311 again moves to closed position and remain in closed position.
The flap 311 generally is in close position and form tight sealing with the vent plate 310 when the air pressure inside the operator cabin or interior compartment is less than certain pre-determined air pressure value.
Referring to FIG. 4, one more alternate preferred embodiments of the present invention consist of air pressure vent valve assembly 500, an air filter unit 412, an outer duct 413, a blower 414, a suction box 415, and a hose 416. The air pressure vent valve assembly 500 is mounted on the outer panel of the operator cabin or interior compartment. The air pressure vent valve assembly 500 further connected to the outer duct 413 by means of the hose 416.
The blower 414 is provided for suction and circulation of air inside the suction box 415. The air filter unit 412 is provided for filtering external fresh air and further circulating to the suction box 415 via the outer duct 413.
When the operator or occupant wants to increase the air pressure or create positive air pressure inside the operator cabin or the interior compartment, he has to switch on the blower 414. As the blower 414 starts working, the external fresh air will be sucked towards the suction box 415. The external fresh air initially will be filtered through the air filter unit 412 and then supplied to the blower 414 and suction box 415 via the outer duct 413.
When the blower 414 is in working condition and fresh air is introducing into the operator cabin through the suction box 415 and the low pressure area is created between the blower 414 and the air filer unit 412 in the outer duct 413.
The outer duct 413 and the air pressure vent valve assembly 500 is connected by using the hose 416 which keeps the air pressure vent valve assembly 500 in close position with the assistance of the low air pressure created between the blower 414 and air filer unit 412 in the outer duct 413.
When the blower 414 is in non-working condition in operator cabin, there will not be the low pressure area created between the blower 414 and air filer unit 412 in the outer duct 413. In such condition the air pressure vent valve assembly 500 will be in normal and original condition
In such case, the high air pressure created inside the interior compartment due to closing door or window of the interior compartment may be released to outer atmosphere through the air pressure vent valve assembly 500.
Referring to FIG. 5, the configuration and design of the air pressure vent valve assembly 500 is explained in details. The air pressure vent valve assembly 500 comprising of a flap 511, a vent plate 517, a valve screw 513, a nut washer 514 and at least two bond structures 515 & 156 which keep the flap 511 in close position and form tight seal with the assistance of the low air pressure created in the outer duct 413 connected with each other by a duct.
The air pressure vent valve assembly 500 arranged in such way that the flap 511 is placed over the vent plate 517 with the help of fastening means such as valve screw 513 and further it is tightened by using nut washer 514. The vent plate is mounted on the outer panel 512 of the operator cabin by fastening means such as mounting screw (not shown in FIG)
The flap 511 made from a flexible and resilient material so that when flap 511 is in closed position a tight seal is formed between bond structures 515 & 516, valve plate 517 and flap 511. The flap 511 is made from such material that the flexibility, resilience and stiffness of flap material is such that the flap get opened when air pressure of the operator cabin or interior compartment is more than certain pre-determined air pressure value. As the air pressure of the operator cabin is exceed the certain pre-determined air pressure value, the flap 511 get pushed outside hence valve get opened.
The air pressure vent valve assembly 500 constructed in such manners that when the blower 414 is in working condition the low air pressure created in outer duct 413 creates suction in the hose 416 and further the bond structures 515 & 516. Due to suction the bond structures 515 & 516 pull the flap 511 towards the vent plate 517 and further it forms tight sealing. The flap 511 remain forms tight sealing till the blower 414 is in working condition and when the blower 414 stops working then the flap 511 gets into its original or normal closed position. The flap design and flap material resilience provided such that when the operator cabin or interior compartment air pressure exceed the pre-determined pressure value, the flap 511 gets flex and open the vent valve assembly to permit a flow of air out of the operator cabin or interior compartment.
The vent plate 517 has inner and outer surface and the flap 511 may reside either on the inner or the outer surface depending upon the embodiment of the invention. The vent plate 517 may be mounted either inner or outer side of the panel 512 of the operator cabin or interior compartment. The vent plate 517 is mounted on the panel of the operator cabin or interior compartment by means of at least one fastening means such as mounting screw (not shown in FIG). The fastening means may be fitted to the operator cabin or interior compartment panel 512 from the inside or outside depending upon design and mounting of vent plate 517. The flap 511 is mounted by valve screw 513 merely as an example and it is not intended to be limiting thereto. The flap 511 further may be tightened from the other side by means of the nut washer 514, so that the flap 511 may not detached from the valve screw 513.
In the sealed operator cabin as the door or window (not shown in FIG.), the air pressure inside the operator cabin or interior compartment get increased. If the pressure of inside the operator cabin or interior compartment exceeds certain pre-determined air pressure value then the flap 511 automatically get opened. The flexibility or resilience of flap material is such that it moves when air pressure inside the operator cabin or interior compartment exceeds certain pre-determined air pressure value. When the air pressure inside the operator cabin or interior compartment become less than certain pre-determined air pressure value then the flap 511 again moves to closed position and remain in closed position.
Referring to FIG. 6, the configuration and design of the flap used in air pressure vent valve assembly 500 is explained in details. The flap 600 is mounted on air pressure vent valve assembly 500 by means of fastening means which passes through the opening 615 provided in the centre of the flap 600 as shown in FIG. 6. The flap 600 further may be tightened from the other side by means of the nut washer (not shown on FIG) so that the flap 600 may not detached from the said fastening means. The flap 600 provided with at least one opening 614 provided on the periphery aligning with the bond structure 611 & 613 provided on the air pressure vent valve assembly. The area of the opening 614 may be equal to the area of opening formed by the bond structures 611 & 613 respectively. The opening 614 may be concentric and co-axial with the bond structures 611 & 613. With reference to earlier FIGS., during the blower 414 is in working condition the suction force created in the hose 416 and further in the bond structure 611 & 613. The flap 600 get attracted towards the bond structures and the vent plate (not shown in FIG) due to suction force created in the bond structure 611 & 613 and further it forms tight sealing between the vent plate, the bond structure 611 & 613 and the flap 600 hence air pressure vent valve assembly moves in close position. The multiple diaphragms 616 may be provided on the flap 600 which get opened when pressure of inside the operator cabin or interior compartment exceeds certain pre-determined air pressure value.
The said flap 600 is made up from rubber or plastic or any other material and generally is in circular shape. However it is noted that the illustrated circular shape of flap merely shown as an example and is not intended to be limiting other shapes such as rectangular, oval, square etc.
The flap 600 generally is in close position and form tight sealing with the vent plate when the air pressure inside the operator cabin or interior compartment is less than certain pre-determined air pressure value.
The abovementioned description describes the exemplary embodiments of the present invention. One skilled in the art will easily understand from the description and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without changing scope of the invention as defined by the following claims.