Air conditioning filter

A vehicle includes an operator's cab having an air inlet and an air filtration system, and an air outlet, wherein the air filtration system comprises a filter element, and a filter container for receiving the filter element, the operator's cab comprising a chamber for receiving the filter container housing the filter element, the filter container being movable into and out of the chamber between a filtering position and an emptying position, wherein with the container in the emptying position the filter element may be removed from the container, and the container emptied of debris, and wherein the filter container comprises at least one air inlet opening and at least one air outlet opening, and wherein with the container in the filtering position the openings are aligned with the air inlet and air outlet such that air may be drawn through the filter into the cab.

BACKGROUND OF THE INVENTION

This invention relates in general to air conditioning for vehicles, and in particular to the housing of the filter of such an air conditioning unit.

Vehicles, such as agricultural tractors and combine harvesters, work in dusty environments. A requirement exists for air entering the operator's cab of such vehicles to be filtered in order to remove dust particles. Furthermore, such vehicles are often fitted with air conditioning to maintain the temperature of the operator's cab at an acceptable level. There is a requirement to filter out dust particles from the air entering an air conditioning system in order to prevent the condenser from becoming blocked. It is necessary to clean or change air filter elements relatively frequently.

In a current system, the air filtering elements of the air conditioning unit are located in the roof of the cab. They are accessed by removing a hatch on the top of the roof. In order to complete this task it is necessary for the person removing the filter elements to stand on the set in the tractor cab with his upper body passing through the hatch.

In another system currently on the market, the filtering element is held in the side of the roof canopy. One problem associated with this arrangement is that the filter element is long, flexible, and difficult to manipulate. During the procedure of removing the filter from its housing, dust may fall out of the filter element.

The object of the invention is, therefore, to provide an improved arrangement for housing the filter element of an air conditioning system for a vehicle having a cab.

SUMMARY OF THE INVENTION

The invention provides a vehicle comprising an operator's cab having an air inlet, an air filtration system, and an air outlet, wherein the air filtration system comprises a filter element and a filter container for receiving the filter element. The operator's cab comprising a chamber for receiving the filter container housing the filter element, the filter container being moveable into and out of the chamber between a filtering position and an emptying position, wherein with the container in the emptying position the filter element may be removed from the container and the container emptied of debris. The filter container comprises at least one air inlet opening and at least one air outlet opening. With the container in the filtering position, the openings are aligned with the air inlet and air outlet such that air may be drawn through the filter into the cab.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now toFIGS. 1to4, there is shown a cab1having a roof2. A filter container3is removably mounted in the roof2, access to the container being provided by hatch10. Hatch10is pivotally attached to the structure of roof2of the cab1and can be removed from a closed position, as shown inFIG. 2, to an open position, as shown in FIG.3. The hatch10comprises a suitable fastener to fasten the hatch10in the position shown in FIG.2.

The container3consists of five sides, the top being completely open in order that the filter7may be freely placed in and removed from the container3. The base and one side of the container are continuous, whilst the continuity of one side and one of the ends are interrupted by openings6. The openings6provide pathways for air to be drawn from outside through the elements8of the filter7and into the cab. Also, air from the cab may re be re-circulated from the cab, through the filter, and back to the cab.

FIGS. 2 and 5illustrate the path taken by fresh air drawn in from outside the cab. The roof2of the cab1comprises an air inlet12. Air is drawn through the inlet and through the elements8of the filter7, the filtered air egressing the filter through the top9, which comprises suitable apertures. The filtered air passes through ducting and, if required, the air conditioning unit before entering the cab1through vents13and14. The cab comprises a recirculation door15. When the driver wishes to re-circulate the air in the cab, rather than drawing in fresh air from outside the cab, air is drawn through the grille15and via filter7back into the cab through vents13,14.

Rails11are mounted inside the roof. As can be seen fromFIG. 3, the ends of the upper and lower rails11are bent in order to facilitate insertion and removal of the filter container3from the roof. The filter container3comprises bosses5on opposite sides of the container. The bosses5are substantially circular and are of diameter slightly less than the distance between the upper and lower rails11measured in the vertical direction, thereby providing a sliding fit between the bosses5and the rails11. The rails11may be formed by plastics mouldings. In one embodiment, the ends of the rail11proximal the hatch10comprise indents17into which the bosses5may drop, thereby permitting the container3to be brought into a position where the end of the container distal from the bosses5is lower than the bosses, without the container being detached from the cab (see FIG.3). This feature facilitates emptying because the operator does not need to hold both ends of the container whilst removing and/or replacing the filter cartridge.

FIG. 2shows that when the container3complete with the filter7is inserted into the roof of the cab, the filter7is held in place by frame members16which press down on the top9of the filter, thereby preventing upward movement of the filter7. This ensures that air entering the container3via the fresh air inlet and air intake holes6in the container3may only pass into the cab through the top9of the filter7as shown by the arrow “a” in FIG.2. Absent a seal between the container3and the top9of the filter7, air could pass into the cab without passing through the filter.

The height x of the end of container3closest to the hatch10is greater than the height y of the end of the container3distal from the hatch. Hence, the base of the container3is at a slight angle to the horizontal, falling towards the hatch10. With the engine of the vehicle running, small vibrations are induced in the vehicle's chassis. These vibrations are transmitted, albeit in attenuated form, to the driver's cab1. The vibrations cause the dust filtered from air passing through the filter element8to move towards the end of the container closest to the hatch10. Equally, the rails11may be mounted in the roof2of the cab such that they are at a slight angle to the horizontal, thereby disposing the container3at a slight angle to the horizontal.

As can be seen fromFIG. 4, the recess into which the container3slides is located just above the door which gives access to the operator's cab. Placing the filter in this position renders changing and/or cleaning the element an easy task. To change or clean the filter, the operator opens the hatch10, grips the handle4, and pulls the container3, with the filter7, out of the recess. The bosses5locate in indents17in the slides, and the container3is allowed to pivot downwards into the position shown in FIG.4. The operator may then remove the filter7for cleaning or replacement. Dust accumulated in the container will fall out of the container through the opening6in the end of the container.

The container3may be completely removed from the recess by lifting it out of the indents17.

A second embodiment of the invention is illustrated inFIGS. 6to10. Where appropriate, like numerals are used to reference like parts. The filter container3is similar to that of the first embodiment. However, it is of simpler design, insofar as the sides20do not comprise bosses or wheels extending therefrom. The roof2of the operator's cab comprises a chamber defined by an end wall22, a floor23, and sides24. As with the first embodiment, the chamber includes frame members16extending across the upper part of the chamber. As shown inFIG. 7, with the filter container in the filtering position, the top9of the filter element presses upwardly against the frame members16, which resist the upward force to securely fasten the filter element in position in the filter container3. The frame members could be replaced by other structures against which the filter element may be pressed. For example, the chamber may comprise a substantially flat ceiling formed for a material having sufficient stiffness to resist the upward force exerted by the filter element.

In order to install the filter container in the filtering position, an operator slides it into the chamber until the container comes to rest against a stop, which in this case is the end wall22of the chamber. A locking arrangement comprises a cam member25rotatably mounted on to the filter container3by a pin26. A handle27is attached to the cam member25. By gripping the handle27, an operator can rotate the cam member25in the direction indicated by the arrow “z”. The operator can also grip the handle to withdraw the container3from or insert the container3into the chamber.

It is desirable to lock the container3in the position shown in FIG.7. This is done by rotating the cam member25from the position shown inFIG. 9to that shown inFIG. 10, where the cam member25is substantially vertical, and is engaged with an indent28. Engagement of the cam member25with the indent28serves two purposes. First, movement of the container in the direction indicated by arrow “m” inFIG. 7is prevented. Second, the filter container is lifted upwardly so the top of the filter9engages with the frame members16to hold the filter element in place in the container3.

The hatch10shown inFIGS. 6to8functions in the same manner as the hatch10shown inFIGS. 1to3.

As with the first embodiment, the floor of the filter container3is set a slight angle below the horizontal so the dust and debris settles towards the end of the filter container3proximal the hatch10.

The invention provides for easy access to the filter and for the filter to be held in the container as it is extended from the cab. The container collects any dust falling from the filter both prior to and during removal of the filter element. The potential for exposure of the vehicle operator to dust during the cleaning and/or replacement of the filter is much reduced by this invention.