AIR FILTRATION SYSTEM FOR OPERATOR'S CAB

Abstract: An air filtration system (25) for the operator's cab (12) on a self-propelled crop harvesting machine (10) is disclosed wherein the service door (27) for access to the filter cartridge (40) is positioned above the access door (20) into the cab enclousure (18). Since the open position of the service door (27) interferes with the opening of the cab access door (20), the filter cartridge (40) cannot be changed unless the cab door (20) is closed. A movable latch engagement member (30) is engageable with lift members (37) affixed to the service door (27) to lift the latch engagement member (30) out of an engageable position with the door latch (28) to prevent the service door (27) from being latched unless a filter cartridge (40) is positioned within the filtration chamber (35). The filter cartridge (40) restricts the movement of the latch engagement member (30) to permit engagement thereof with the door latch (28). The resultant structure provided an air filtration system (25) that requires a filter cartridge (40) within the filtration chamber (40) before the service door (27) can be latched.

Description: The present invention relates generally to operator's cabs such as mounted on self-propelled crop harvesting machines, such as e.g. combines, and, more particularly, to an improved air filtration system that requires the use of a filter cartridge within the filtration chamber to enable the service door to be latched. Modern self-propelled crop harvesting machines are generally equipped with an enclosed operator's cab in which the operator is seated to control the harvesting operation of the machine. Such operator's cabs are generally provided with environmental controls, such as air conditioning and sound absorbing materials, to improve the quality of work environment for the operator. Operator cabs are generally mounted at an elevated position on the crop harvesting machine to afford the operator a field of view of the harvesting operation relative to the gathering of crop material from the field in which he is operating. To permit this field of view, the cab enclosure is provided with a number of transparent panels, normally glass, supported from vertical posts extending between the floor member and the roof member of the cab. To permit access to the cab, the cab enclosure is provided with an access door pivotally mounted to one of the support posts for movement between closed and opened positions. Since the cab enclosures are generally sealed to maintain environmental conditions within the cab, it is necessary to provide a system for the inlet of fresh air into the enclosure. Typically, such systems are provided within the cab roof and include an air filtration system to filter dirt and debris from the inlet air and, thereby, keep the interior of the cab enclosure as clean as possible. US-A-4.503.749 shows an example of such a typical cab. It would be desirable to provide an inlet air filtration system which would be easy and convenient to service from outside the cab enclosure, that would require the cab door to be closed during service operations, that would provide a visual indication when the filter cartridge is not installed, and that would not require the roof of the operator's cab to be lifted to affect service operations. According to the present invention, an operator's cab is provided comprising : a roof member and an enclosure for peripherally extending around an operator's station; said enclosure having an access door movable between closed and opened positions to permit access to and from the interior of the enclosure; air inlet means incorporated into the roof member to permit the introduction of air within the enclosure, air filtration means including a removable filter cartridge supported by the roof member in operative position relative to the air inlet means to filter air entering the enclosure through the air inlet means and a service door supported by the roof member for movement between a closed position and an opened position for permitting access to the air filtration means and being provided with a latch member engageable with a latch engagement member to retain the service door in the closed position; the operator's cab being characterized in that the latch engagement member is engageable with the filter cartridge and is movable when not engaged by said filter cartridge; and positioning means are associated with the service door which are positionably engageable with the latch engagement member when the service door is moved into a closed position to move said latch engagement member out of its engageable position with the latch member when the filter cartridge is not engaged with the latch engagement member. The filter cartridge restricts the movement of the latch engagement member to permit engagement thereof with the door latch when the cartridge is installed in the filtration chamber. In other words, the resultant structure provides an air filtration system that requires a filter cartridge within the filtration chamber before the service door can be latched. Preferably, the service door for access to the filter cartridge is positioned above the access door into the cab enclosure and such that the open position of the service door interferes with the opening of the cab access door, whereby the filter cartridge cannot be changed unless the cab door is closed. Accordingly the introduction of extraneous dirt and debris into the cab enclosure when changing the cartridge is excluded. Also the risk of introduction of non-filtered air into the cab enclosure during the operation of the harvester due to a lack of a filter cartridge within the air filtration system is minimized. Furthermore the system provides a visual indication when a filter cartridge is not installed, simply because under this condition the service door cannot be latched in its closed position. Another advantage of this invention is that the air filtration system is easy and convenient for service from outside the cab without requiring the cab roof to be lifted. The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: Fig. 1 is a side elevational view of an operator's cab for a self-propelled crop harvesting machine incorporating the principles of the instant invention, the crop harvesting machine being fragmentarily shown; Fig. 2 is a partial cross-sectional view taken along lines 2-2 through the roof member of the operator's cab to show the air filtration system; the pivotal movements of the service door and the cab access door being shown in phantom; Fig. 3 is a partial cross-sectional view taken along lines 3-3 of Fig. 2 through the filter cartridge to show the latch engagement member; Fig. 4 is a partial cross-sectional view corresponding to the view seen in Fig. 2 with the service door being open to permit servicing of the air filtration system, the movement of the removable filter cartridge being shown in phantom; and Fig. 5 is a partial cross-sectional view corresponding to the view of Fig. 4 showing the operation of the positioning members to move the latch engagement member out of an engageable position with the service door latch, the corresponding positions of the latch engagement member and filter cartridge being shown in phantom when the filter cartridge is inserted into the filtration chamber. Referring now to the drawings and, particularly, to Fig. 1, a side elevational view of the operator's cab mounted on a self-propelled crop harvesting machine, commonly referred to as a combine, can be seen. Any left and right references are used as a matter of convenience and are determined by standing at the rear of the machine, facing the forward end, the direction of travel. The self-propelled crop harvesting machine 10 is fragmentarily shown and represents a conventional combine; however, one skilled in the art will readily realize that the principles of the instant invention will not be limited to the type of machine on which the operator's cab is mounted. As a matter of fact, the operator's cab according to the present invention may be used on a wide variety of machines, inclusive tractors and machines other than agricultural machines. The cab according to the invention even may be used on pull-type machines in the exceptional situation where pull type machines are equipped with their own cab, although clearly the operator's cab according to the invention will be used most commonly on self-propelled machines. As best seen in Fig. 1, the operator's cab 12 includes a floor member 14, a roof member 16 vertically spaced above the floor member 14 and an enclosure 18 extending around and encompassing an operator's station (not shown) located in the interior of the cab 12. Support posts 19 of the operator's cab 12 support the roof member 16 above the floor member 14 and at least partially also support the enclosure 18.To gain access to the operator's station in the interior of the cab 12, the left side of the enclosure 18 is provided with an access door 20 pivotally connected to a support post 19 for movement between opened and closed positions. Referring now to Figs. 1, 2 and 3, the structural details of the air filtration system 25 can best be seen. The service door 27 is pivotally connected to the roof member 16 by a hinge axis 29. The service door 27 is positioned immediately above the access door 20 into the cab 12. As best seen in Figs. 2, 4 and 5, the opening of the service door 27 positions the service door 27 within an interferring position with the opening of the access door 20. As a result, the servicing of the air filtration system 25 through the service door 27 requires a closing of the access door 20, minimizing the entry of dirt into the cab 12 during the servicing operation. Referring now to Figs. 2-5, it can be seen that the service door 27 is provided with a spring latch 28 that is engageable with a latch engagement member 30 positioned within the interior of the filtration chamber 35. The latch engagement member 30 is comprised of a frame like filter support member 32 and spring members 34 positioned below the filter support member 32 and optionally connectable thereto with fasteners (not shown). The filter support member 32 is provided with an opening 33 extending therethrough and aligned to receive the latch member 28 therewithin. The engagement between the latch member 28 and the opening 33 in the filter support member 32 retains the service door 27 in its closed position as seen in Fig. 2. The service door 27 is provided with positioning or lift members 37 positioned for engagement with the spring members 34 when the service door 27 is moved into the closed position. As best depicted in Fig. 5, the lift members 37 engage the spring members 34 and lift the latch engagement member 30 upwardly into the filtration chamber 35 when a filter cartridge 40 is not present within the filtration chamber 35. As a result, the opening 33 in the filter support member 32 is lifted out of an engageable position with the latch member 28 and, thereby, the service door 27 cannot be latched into the closed position. The installation of a filter cartridge 40 into the filtration chamber 35 restricts the upward movement of the latch engagement member 30 within the filtration chamber 35 and forces the filter support member 32 to remain in a position in which the opening 33 can receive the latch member 28. The upward forces exerted by the lift members 37 are absorbed and stored through a deformation of the spring members 34, which in turn urge the filter cartridge upwardly against the seal 45. Referring now to all the figures, the operation of the air filtration system can be seen. A means for the inlet of air from outside the cab enclosure 18 is provided within the roof member 16 as indicated by the arrows 42 in Fig. 1. The movement of the air rearwardly through the roof member 16 passes under and up through the filter cartridge 40 as indicated by the air flow arrows 44 in Fig. 2. The seal 45 bridges between the top of the filter cartridge 40 and the top of the filtration chamber 35 to require the flow of air to pass through the filter cartridge 40 before being introduced into the interior of the enclosure 18. One skilled in the art will readily realize that the flow of air can be induced by a fan with the flow of air passing through temperature regulating coils and enclosure outlets into the cab 12. Dirt or other extraneous debris filtered by the filter cartridge 40 can be collected on the bottom of the filter cartridge 40 and on a pan 48 below the filter 40. A servicing of the air filtration system 25 requires a disengagement of the latch member 28 from the opening 33 in the filter support member 32 to permit the service door 27 to be opened. The upward spring forces exerted by the spring members 34, as induced by the lift members 37, are relaxed to allow the filter cartridge 40 to be slid out through the opening created by the opened service door 27. The latch engagement member 30 and dust pan 48 can be lifted out to facilitate a cleaning of the filtration chamber 35. When the components are reassembled within the filtration chamber 35, the service door 27 cannot be latched into its closed position unless a filter cartridge 40 is also inserted within the chamber 35. Since the service door 27 cannot be latched the access door 20 of the enclosure 18 cannot be opened to gain entrance into the cab 12 without impacting the service door 27.

Claims: An operator's cab (12) comprising : a roof member (16) and an enclosure (18) for peripherally extending around an operator's station; said enclosure (18) having an access door (20) movable between closed and opened positions to permit access to and from the interior of the enclosure (18); air inlet means incorporated into the roof member (16) to permit the introduction of air within the enclosure (18), air filtration means (25) including a removable filter cartridge (40) supported by the roof member (16) in operative position relative to the air inlet means to filter air entering the enclosure (18) through the air inlet means, and a service door (27) supported by the roof member (16) for movement between a closed position and an opened position for permitting access to the air filtration means (25) and being provided with a latch member (28) engageable with a latch engagement member (30) to retain the service door (27) in the closed position, characterized in that the latch engagement member (30) is engageable with the filter cartridge (40) and is movable when not engaged by said filter cartridge (40); and positioning means (37) are associated with the service door (27) which are positionably engageable with the latch engagement member (30) when the service door (27) is moved into a closed position to move said latch engagement member (30) out of its engageable position with the latch member (28) when the filter cartridge (40) is not engaged with the latch engagement member (30). An operator's cab (12) according to claim 1, characterized in that the latch engagement member (30) is operable to restrict movement of the filter cartridge (40) when engaging the latter. An operator's cab (12) according to claim 1 or 2, characterized in that the air filtration means (25) includes a chamber (35) in which the filter cartridge (40) is positionable for filtration engagement with the latch engagement member (30); said latch engagement member (30) being movable within the filtration chamber (35) and said filter cartridge (40) being operable to restrain the movement of the latch engagement member (30) within the chamber (35) to permit engagement thereof by the latch member (28). An operator's cab (12) according to claim 3, characterized in that the latch engagement member (30) includes a filter support member (32) having an opening (33) therein for releasably receiving the latch member (28) to retain the service door (27) in the closed position and a spring member (34) connected to the filter support member (32) and positioned between the filter support member (32) and the positioning means (37) for operative engagement with the positioning means (37). An operator's cab (12) according to claim 4, characterized in that the spring member (34) transfers positioning forces, exerted by the positioning means (37) when the service door (27) is moved to the closed position, to the filter support member (32) to position the filter support member (32) within the chamber (35) and out of an engageable position with the latch member (28) when the movement of the filter support member (32) is not restrained by the filter cartridge (40). An operator's cab (12) according to claim 5, characterized in that the spring member (34) is deformable to absorb said positioning force of the positioning means (37) when the filter cartridge (40) is within the chamber (35) and restraining the movement of the filter support member (32) to keep said opening (33) in a position to receive the latch member (28). An operator's cab (12) according to claim 6, characterized in that the positioning means comprises at least one angled member (37) affixed to the service door (27) for engagement with the spring member (34) when the service door (27) is closed. An operator's cab (12) according to any one of the preceding claims, characterized in that the service door (27) interferes with the movement of the access door (20) into an opened position when said service door (27) is not in the closed position, requiring the access door (20) to be in a closed position to permit an opening of the service door (27). An operator's cab (12) according to claim 8, characterized in that the service door (27) is accessible only from outside the enclosure (18), the opened position of the service door (27) being located externally of the access door (20). An operator's cab (12) according to claim 8 or 9, characterized in that the service door (27) is hingedly supported by the roof member (16) above the access door (20) and is pivotally movable in one direction between the closed and opened positions and in that the access door (20) is pivotally movable in another direction between the closed and opened positions. An operator's cab (12) according to any one of the preceding claims characterized in that the air filtration means (25) further also includes a dirt collection pan (48) positioned below the latch engagement member (30) to collect debris filtered from the air passing through the filter cartridge (40).

Inventors: HURLBURT, JOSEPH C.
Applicants: FORD NEW HOLLAND, INC. (A DELAWARE CORP.)
Application year: 1986
Main classification: B60H3
IPC codes: B60H3