Positive pressure vent for a vehicle

According to the invention, there is provided a positive pressure vent for a vehicle. The vent includes an inlet chamber having an air intake port facing into an air stream generated by motion of the vehicle so as to collect air and form a positive pressure inside the inlet chamber. There is further provided a filter adapted to filter air from the inlet chamber of particulate matter. A filtered air path is further provided for allowing filtered air from the filter to travel to the interior of the vehicle under the urging of the positive pressure from the inlet chamber.

FIELD OF INVENTION

The present embodiments relate to vents and in particular to a vent for a vehicle.

The embodiments have been developed primarily for use as a positive pressure vent for a vehicle and will be described hereinafter with reference to this disclosure. However, it will be appreciated that the embodiments are not limited to this particular field of use.

BACKGROUND

The following discussion of the prior art is intended to place the invention in an appropriate technical context and enable the associated advantages to be fully understood. However, any discussion of the prior art throughout the specification should not be considered as an admission that such art is widely known or forms part of the common general knowledge in the field.

When travelling in dusty environments, recreational vehicles such as mobile homes and caravans and also mining trucks suffer from dust ingress as a result of a negative pressure which develops inside the vehicle while moving. This negative pressure inside the vehicle is due to the air currents moving around the vehicle, which cause the dusty turbulent air to enter the vehicle through ventilation apertures and general venting, which consequently deposits dust inside.

In order to address this problem, it is known in the prior art to provide a small hatch in the roof of the vehicle called a “pressure hatch” or a “scupper vent”. The hatch, when opened at an angle facing towards the direction of motion, scoops air into the vehicle from the passing airstream to force it in into the vehicle and create a net positive pressure inside the vehicle. While such a device is simple, it has a number of drawbacks. Primarily, pressure hatches or scupper vents will only work when they are opened by a user. In this regard, given their position on mobile homes and caravans, they are often difficult to access and as a result, rarely opened. Compounding this problem, even if they are opened, they allow rain to enter the vehicle when opened.

A further problem with pressure hatches or scupper vents is that even if it not raining, gravel, insects and some dust enters through the vent, which is particularly problematic given the position of the vents when installed.

Another known approach to alleviate the problem of dust ingress is to attempt to cover all apertures through which dust may enter the vehicle, such as refrigerator vents and cross-flow vents. This is generally ineffective as it is usually impossible to cover all apertures and also is very time-consuming. This solution can also be dangerous as when cooking gas is used and/or to leave the vents closed when inhabiting the vehicle due to potential suffocation.

A further known and more complex solution implemented on one brand of caravans involves use of a high-pressure tank, pump, filters and low pressure air bladders to always maintain a positive air pressure. This solution is particularly expensive, cumbersome, adds significant weight and is known to be not fully effective.

It is an object of the present embodiments to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

It is an object of the present embodiments in at least one preferred form to provide an improved system for the prevention of dust ingress in moving vehicles.

SUMMARY OF THE INVENTION

According to one aspect of the present embodiments, there is provided a positive pressure vent for a vehicle, including:

an inlet chamber having an air intake port facing into an air stream generated by motion of the vehicle so as to collect air and form a positive pressure inside the inlet chamber;

a filter adapted to filter air from the inlet chamber of particulate matter; and

a filtered air path for allowing filtered air from the filter into the interior of the vehicle under the urging of the positive pressure from the inlet chamber.

In one embodiment, the filtered air path includes an air feeder channel.

In one embodiment, the filter is a liquid trap filter that causes the collected air to pass through a liquid to filter out the particular matter.

In one embodiment, the liquid trap filter includes a baffle to minimise water splashing during use.

In one embodiment, the liquid trap filter includes a plurality of notches to promote water bubbling through the liquid trap filter.

In one embodiment, the filter is a membrane filter that causes the collected air to pass through a membrane to filter out the particular matter.

In one embodiment, the filter is removable and replaceable from the interior of the vehicle.

In one embodiment, the filter is housed in a filter housing.

In one embodiment, the filter housing is adapted to be positioned inside the vehicle.

In one embodiment, the filter housing includes a hinged cover for accessing and removing the filter.

In one embodiment, the inlet chamber includes a centrally disposed cup formation defining a narrowing air transfer channel on each side for increasing the velocity and directing of the airflow within the inlet chamber.

In one embodiment, the cup formation is generally oval shaped.

In one embodiment, the cup formation is hollow and includes an inner space.

In one embodiment, the inner space is separated by a wall defining a non-filtered area and a filtered area.

In one embodiment, the non-filtered area is in fluid communication with the air transfer channels and the filtered area forms part of the filtered air path.

In one embodiment, the inlet chamber includes an outlet aperture in fluid communication with the air transfer channels

In one embodiment, the inlet chamber includes one or more arcuate formations for directing airflow into the outlet aperture.

In one embodiment, the one or more arcuate formations and the outlet aperture are generally disposed at the rear of the inlet chamber.

In one embodiment, the inlet chamber includes at least one water extraction aperture for egress of any collected water.

In one embodiment, the vent includes a flow ventilation channel disposed on each lateral side of the air inlet chamber.

In one embodiment, each cross flow ventilation channel is in fluid communication with the interior of the vehicle.

According to a one aspect, there is provided a positive pressure vent for a vehicle, comprising: an air intake port positioned outside the vehicle and facing into an air stream generated by motion of the vehicle so as to collect air from the air stream into a chamber and form a positive pressure inside the chamber; an opening extending from the chamber to an inside of the vehicle so as to provide a path for ingress of the collected air in the chamber into the interior of the vehicle under the urging of the positive pressure in the chamber; a cover positioned with respect to the aperture so as to prevent rain from entering into the interior of the vehicle; and wherein the opening and the air intake port are sized and shaped so as to maintain a positive interior pressure inside the vehicle above a minimum vehicle speed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments will now be described in detail with reference to the accompanying drawings. In the drawings, the same elements are denoted by the same reference numerals throughout. In the following description, detailed descriptions of known functions and configurations incorporated herein have been omitted for conciseness and clarity.

Referring to the accompanying drawings and initially toFIGS. 1 and 2, there is shown a positive pressure vent10for a vehicle12such as a caravan, recreational or mining vehicle. In the present embodiment, the vent10is located in the front portion of the roof11of a caravan, well away from turbulent flow and substantial dust at a rear of the vehicle. However, in other not shown embodiments, the pressure vent10may be placed in any position on a vehicle that has access to airflow due to the forward motion of the vehicle. In one alternative location, the vent may be installed in a hatch in the roof of the vehicle.

Referring now toFIGS. 3 to 5, the pressure vent10includes an air inlet chamber14adapted for positioning outside the vehicle once the vent is installed. The air inlet chamber14has an air intake port16facing into an air stream generated by forward motion of the vehicle so as to collect air and form a positive pressure inside the air inlet chamber14by virtue of the velocity of the continually entering airstream.

The vent10further includes a removable filter18housed in a filter housing20. As shown inFIG. 3, when the vent10is installed the filter housing20and filter18are both located inside the vehicle. According to some embodiments, pressurised air enters the filter18from the inlet chamber and is consequently filtered of any particulate matter.

In order for the filtered air to enter the vehicle, a filtered air path25is provided to the inside of the vehicle. The filtered air path25runs from the filter exit point through the filter housing and up into the inlet chamber14. The filtered air path25includes cylindrical air feeder channel26, which extends from approximately halfway into the inside the inlet chamber14to an outlet port28providing a final and straightened exit conduit for the pressurised and filtered air into the vehicle.

To allow for installation of the vent10, an opening22is provided in the proposed location in between the inlet chamber14and the filter housing20. As is commonly known in the art, lining elements are/or sealing compounds are typically provided to line and seal the opening22. A fixed cover23as part of the inlet chamber14, is provided to completely cover the opening22with a substantial overlap thereby generally preventing ingress of rain. As a result of the overlapping cover23, the vent10can always be ready to operate as rain cannot enter through the opening or through the outlet port28. Consequently, it is not necessary for the user to remember to open/close or otherwise activate the vent10as required in some prior art devices.

It will be appreciated that using this arrangement, air30enters the filter housing20under the urging of the positive pressure from the inlet chamber14, and then into filter18where particulate matter is removed. The filtered air then leaves the filter18and follows the filtered air path25entering air feeder channel26to finally leave the positive pressure vent10and into the vehicle interior via outlet port28. In this way, filtered air is supplied into the vehicle at a positive pressure during motion to counteract dust or particulate matter ingress through the various gaps and vents in the vehicle which also occurs during motion.

In the illustrated embodiment ofFIGS. 3 to 5, the filter18is a removable and replaceable liquid trap filter31that filters the supplied air of particulate matter by passing it through a liquid32. The liquid32may be water or a mix of water and an antibacterial agent and/or fragrance substance. The filter18is sized to filter the collected air of particulate matter while maintaining sufficient airflow and positive interior pressure.

As best shown inFIGS. 3 and 4, the liquid trap filter31includes a baffle34to contain liquid32splashing and the associated noise during use. Further, it is proposed that air transfer through the liquid32will be primarily by way of air bubbles through the liquid32. For this reason, the liquid trap filter31also includes a plurality of notches36to promote air bubbling through the liquid once it enters from the air inlet chamber14.

In other not shown embodiments, the filter may be a dry membrane filter or other type of filter.

With reference toFIGS. 6 to 9, it can be seen how the filter18of the present embodiments is removable and replaceable from the interior of the vehicle by simply unclipping hinged cover38, pulling out the old filter and replacing it with a new one. In this way, replaceable filters are easily installed as required. Importantly, the pressure vent is adaptable to use different types of filters that simply fit into the vent in the same way. In this regard, it will be appreciated that the various types of replaceable filters should be shaped similarly as that depicted inFIGS. 6 to 9to fit in the filter housing20. In further embodiments, the positive pressure vent10includes a viewing window or indication means in order to determine if the filter requires replacement. In other not shown embodiments, the filter may be a dry membrane filter.

With reference toFIGS. 3-5, the inlet chamber14includes a generally oval shaped and hollow cup formation40centrally disposed in the inlet chamber14. The cup formation40extends from the cover23to the base of the inlet chamber thereby defining a pair of laterally disposed narrowing air transfer channels42on each side of the formation40, as best shown inFIG. 5. Due to their shape, the air transfer channels act to increase the velocity and pressure of the contained airflow relative to the velocity of the air as it enters the air intake port16. Each air transfer channel42directs airflow to the rear of the inlet chamber, where it enters an outlet aperture44to be transferred to the filter housing20. To assist in redirecting the airflow into the aperture entry with a minimal pressure loss, there is further provided a pair of arcuate turning formations46located at the rear of the inlet chamber. Advantageously, increasing the airflow velocity and pressure within the inlet chamber will assist in overcoming the pressure loss of the airflow transfer through the filter20.

As mentioned, the cup formation40is hollow and therefore contains an inner space41. The inner space is separated by wall50to define a non-filtered area52fed by outlet aperture44to deliver airflow to the filter18, and a filtered area54fed by the filter18to deliver filtered airflow to the top of the air feeder channel26. In this way, a compact separation is provided with no cross contamination.

Referring now toFIGS. 4, 9 and 10, whilst it is envisaged that rain water will not enter the inlet chamber14through opening22when the vehicle is not moving, there may be some rain water collected through the intake port16during forward motion of the vehicle. For this reason, inlet chamber14further includes at least one water extraction aperture48located at the rear of the inlet chamber14for egress of any collected water. Due to the shape of the air transfer channels42and the positive pressure and accelerated air flow generated, any contained rain water will be promoted to the rear of the inlet chamber to exit through the water extraction aperture48. As should be evident, due to the provision of lip56, any collected rainwater will not enter the outlet aperture44. Similarly, in other not shown embodiments, the inlet chamber includes further hinged panel or otherwise access to remove any collected grit or dirt that may have accumulated over time.

It will be understood that the design of an effective filtering unit in conjunction with geometry of the intake port16and other aspects of the inlet chamber14require consideration of the desired minimum speed at which a positive pressure is maintained inside the vehicle, which depends not only on the vent itself including the air resistance provided by the filter, but also on the total size of other ingress points in the vehicle, for example refrigerator vents and the like. Persons skilled in the art will appreciate that such design parameters are arrived at by simple hydrodynamic and aerodynamic calculations in conjunction with trial and error.

Returning toFIG. 5, those familiar with the art will appreciate that recreational vehicles and caravans are required to have a minimal amount of cross flow ventilation under design regulations to ensure a minimum airflow to prevent build-up of explosive gases due to leaking gas appliances. It is for this reason that the present embodiment further includes a pair of spaced cross flow ventilation channels100disposed on each lateral side of the air inlet chamber14. These cross flow ventilation channels100are in fluid communication with the inside of the vehicle through a ventilation path104and fed by ventilation inlet ports102as more clearly shown inFIG. 11.

Airflow through the ventilation path104is due to the velocity of airflow through the air channels100resulting from forward motion of the vehicle. This airflow draws out air from the inside of the vehicle from ventilation inlet ports102to exit via the cross ventilation channels100through ventilation exits106. The ventilation path104is therefore in an opposite direction to the positive pressure airflow from the inlet chamber. In this regard, it should be noted that there will be no fluid communication between the ventilation path104and high pressure air path25from the filter18.

With reference toFIG. 11, it should be noted that whilst ventilation inlet ports102and outlet port28are in close proximity to each other, the velocity and pressure of air flowing from the outlet port28is much higher than the airflow being drawn in through the ventilation inlet ports102. Therefore, there will be minimal transfer between these two ports in operation.

Returning toFIGS. 3 and 4, in use, the positive pressure vent10of the present embodiments is easily installed in a vehicle in a roof or any other desired location that is exposed to an air stream when the vehicle is moving. Typically, installation would first involve creating the opening22in the vehicle external surface. In the illustrated embodiment, the inlet chamber14and the filter housing20are separate components thereby allowing the inlet chamber to be installed first from the outside of the vehicle together with appropriate lining or sealing compounds as is commonly known in the art. The filter housing is then installed from inside of the vehicle and secured to the inlet chamber using clip or screw fasteners or adhesive compounds. In other not shown embodiments, the inlet chamber and filter housing are co-formed in one piece and are therefore both installed from above the vehicle and then secured in position. The hinged cover38can then be installed from inside the vehicle.

Advantageously, the operation of vent10is automatically activated by the motion of the vehicle to deliver filtered air at a positive pressure to the inside of the vehicle. In this way, the positive pressure will counteract particulate matter ingress through the various gaps and vents throughout the vehicle, which also occur during motion of the vehicle. The positive pressure vent of the present embodiments is also water proof, insect proof, gravel proof and better dust proof efficiency than known the prior art devices. It has its own filter that is removable and replaceable. It is low cost being ideally formed from plastic injection moulded parts. It also has no moving parts, thereby making its operation extremely reliable within normal maintenance cycles.

It also has the further function of providing cross flow ventilation as required under most statutory design regulations for recreational vehicles providing a significant cost and installation advantage to recreational vehicle manufacturers who choose to install the vent of the present embodiments prior to customer delivery. The ventilation path is not able to be closed thereby to provide uninterruptible minimum ventilation for the interior of the vehicle to satisfy any safety requirements.

Although described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.