Abstract:
The present invention discloses a novel work vehicle cab compartment, such as a tractor cab, that is configured to provide convenient and ample access to under-cab components. The cab compartment is fixedly mounted onto a work vehicle frame and includes a cab footing structure secured to the work vehicle frame and a pivoting floor structure. The pivoting floor structure includes a raised central portion and flange portions, which partially define the floor of the cab compartment. One of the flanged portions mechanically fastened to the cab footing structure while another flange portion is hingedly coupled to a mounting structure that is secured to the cab footing structure. A pivoting seat assembly, including an operators seat, is attached atop a seat suspension that is mounted to the pivoting floor structure. The pivoting floor structure, as well as the pivoting seat assembly, are pivotally moveable in an outwardly direction to expose, and provide access to, vehicle components disposed under the cab compartment while the cab compartment remains fixedly mounted to the work vehicle frame.

Description:
RELATED APPLICATION DATA 
     The present application claims priority to the U.S. Provisional Application No. 60/132,111, entitled “Tractor Cab Providing Under-Cab Access” filed on Apr. 30, 1999, in the names of Randy B. Drake, William C. Roberson, and Bryant E. Ward. 
     The contents of the aforementioned provisional application is hereby expressly incorporated by reference herein in its entirety. 
    
    
     RESERVATION OF COPYRIGHT 
     The disclosure of this patent document contains material, which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF THE INVENTION 
     This invention generally relates to the field of work vehicles. More particularly, the present invention relates to a novel work vehicle cab compartment, configured to provide safe, convenient, and ample access to under-cab components. 
     DESCRIPTION OF BACKGROUND INFORMATION 
     Work vehicles, such as industrial tractors used in construction, excavation, mining, and forestry, typically include a frame supported by the wheels or tracks of the tractor. The frame carries various components of the tractor, such as the engine, transmission, and drive system components, and various working attachments, such as end-loaders, back-hoes, tree-felling heads, grappling devices, or winches are attached to the frame. An operator&#39;s cab is situated atop the frame for affording the operator an elevated field of view, and is therefore disposed above a number of the mechanical components mounted within the frame. 
     The conventional means for providing access to the under-the-cab mechanical components for maintenance, cleaning, or trouble-shooting, is to provide a cab assembly that is pivotally attached to the frame so as to be able to pivot with respect thereto. With the cab tilted with respect to the frame, below-the-cab components then become accessible for cleaning, maintenance, and the like. Tilting of the cab, however, presents a number of disadvantages which make this feature less than ideal for achieving its intended purpose of providing access to under-the-cab components. 
     In order to be able to tilt the cab with respect to the frame, it is often necessary to disconnect connections between cab components and frame-mounted components, such as electrical wires and hydraulic control lines. Disconnecting, and subsequently reconnecting the lines, is in itself an extra task which requires additional time and effort for the cab tilting procedure, but there is also the possibility that connectors can be damaged or improperly reconnected or that reconnections can be forgotten altogether. 
     Certain tractors, such as forestry tractors, must be certified so as to withstand rollovers or objects falling onto the cab. Testing equipment mounted on the cab and frame necessary for such certifications must be disconnected so as to permit the cab to be tilted with respect to the frame, thereby creating potential difficulties in maintaining the required certification. 
     Industrial tractors typically encounter a great deal of wear and tear, which is inherent in the severe working environment in which such tractors are typically operated. This wear and tear can cause the cab tilt apparatus to malfunction, thereby preventing the cab from tilting away from the frame and/or preventing a tilted cab from again closing down onto the frame. This is especially a problem for the cab of a tractor that has been rolled, in which case it is very unlikely that the cab-tilt feature will thereafter operate properly. 
     Because of the size of the cab and the relatively high center of gravity relative to the frame, the cab cannot be tilted too far away from the frame. This limitation is due, in part, to the fact that tilting the cab too far may result in the instability of the tractor. Moreover, there may be space constraints, which limit the extent to which the cab can be extended away from the main frame, especially where maintenance and repairs are performed in an indoor maintenance facility. Consequently, the amount of access actually provided to the under-cab components by tilting the cab is relatively small. 
     As such, for any or all of the above reasons, many tractor owners simply do not or cannot use the cab-tilt feature of their tractor in order to gain access to under-cab components. Typically tractor owners are forced to gain access to such components by removing exterior side panels of the tractor body and/or from beneath the tractor, where possible. Therefore, what is needed is a work vehicle cab compartment, which is capable of providing safe, convenient, and ample access to under-cab components. 
     SUMMARY OF THE INVENTION 
     Work vehicles, designed in accordance with the principles of the present invention, address the need identified above by providing a novel work vehicle cab compartment that is configured to provide safe, convenient, and ample access to under-cab components. 
     In one aspect of the present invention, a work vehicle cab compartment configuration is presented, which is fixedly mounted onto a work vehicle frame. The cab compartment includes a cab footing structure secured to the work vehicle frame and a pivoting floor structure. The pivoting floor structure includes a raised central portion and flange portions, which partially define the floor of the cab compartment. One of the flanged portions mechanically fastened to the cab footing structure while another flange portion is hingedly coupled to a mounting structure that is secured to the cab footing structure. The pivoting floor structure is pivotally moveable in an outwardly direction to expose, and provide access to; vehicle components disposed under the cab compartment while the cab compartment remains fixedly mounted to the work vehicle frame. 
     In another aspect of the present invention, a pivoting seat assembly is provided, which includes an operators seat attached atop a seat suspension. The seat suspension is mounted to the pivoting floor structure. The pivoting seat assembly is configured to move in cooperation with the pivoting floor structure, when the pivoting floor structure is pivotally moved in an outwardly direction. 
     In a further aspect of the present invention, the pivoting floor structure and the pivoting seat assembly are actuated to pivotally move in an outwardly direction by releasing a mechanical fastener secured to one of the flange portions and pulling the pivoting seat assembly in a direction defined by a hinged coupling of one of the flange portions to the cab footing structure. Moreover, the pivoting seat assembly is configured to allow the flange portions of the pivoting floor structure to achieve at least a 90° angle relative to the cab footing structure, when the pivoting floor structure and the pivoting seat assembly are moved in an outwardly direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation showing a tractor cab constructed in accordance with the present invention; 
     FIG. 2 is a rear elevation of the tractor cab showing the cab with the side doors open and the pivoting seat assembly pivoted sideways; 
     FIG. 3 is a top view of the cab showing the side doors open and the seat assembly pivoted sideways; and 
     FIG. 4 is an enlarged end view of a pivoting floor structure of the cab. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-4 depict a work vehicle cab compartment (e.g., tractor cab), constructed and operative in accordance with aspects of the present invention. The cab, generally indicated by reference number  10 , is mounted onto the frame  80  of a work vehicle  82 , such as a tractor, for example, which is only partially shown in the figures. 
     The cab  10  preferably includes a pair of forward support posts  40  and a pair of rear support posts  42 , all extending upwardly from a cab footing structure  84  fixed to the frame  80 . A roof structure  44  extends across and is supported atop the forward support posts  40  and rear support posts  42 . Left and right forward doors  12 ,  16  and left and right rear doors  24 ,  28  are operatively mounted on opposite sides of the cab  10 . In particular, forward left door  12  is pivotally mounted by a hinge  14  to the left-side forward support post  40  and the forward right door  16  is pivotally mounted by hinge  18  to the right-side forward support post  40 . Similarly, the rear left door  24  is pivotally mounted by a hinge  26  to the left-side rear support post  42 , and the rear right door  28  is pivotally mounted by hinge  30  to the right-side rear support post  42 . As shown in FIG. 1, the forward right door  16  includes a see-through panel  20  (e.g., a window or screen). The forward left door  12  also includes a similar see-through panel (not shown). To provide operator escape from the cab  10  should the cab roll over and/or the doors  16  and  12  malfunction, see-through panels  20  can preferably be kicked out of their respective doors. As also shown in FIG. 1, the right rear door  28  includes a see-through panel  32  (e.g., a window or screen), and the left rear door  24  includes a see-through panel  33  (see FIG.  2 ). 
     The rear doors  24  and  28  are preferably quasi-permanently locked, such as by bolting the doors in a closed position to the cab footing structure  84  and/or frame  80  and the roof structure  44 , so that the doors  24  and  28  cannot normally be opened by operators or maintenance personnel. More particularly, (as shown in FIG. 3) locking brackets  29  are attached to the top and bottom edges of the right rear door  28 , and locking brackets  25  are attached to the top and bottom edges of the left rear door  24 . Holes  23  and  27  are formed through the locking flanges  25  and  29 , respectively. The rear doors  24  and  28  are preferably held closed by means of bolts inserted through the holes  23 ,  27  of the respective top edge locking brackets  25 ,  29  and into the roof structure  44 . In addition, bolts are inserted into through the holes  23 ,  27  of the respective bottom locking flanges  25 ,  29  and into the cab footing structure  84 . 
     The forward doors  12  and  16  are held in a closed position against the bolted rear doors  24  and  28  by conventional latches  22  that are operable from inside or outside the cab  10 , so as to provide the operator ready access into and out of the cab from either the left side or right side of the cab. The rear doors  24 , 28  are preferably quasi-permanently locked shut, such as by bolts as previously described because the forward doors  12 ,  16  latch against the rear doors. As such, it is necessary for the rear doors  24  and  28  to provide a solid structure against which the forward doors  12  and  16  can latch. The rear doors  24 ,  28  can be held closed by conventional latches operable from inside or outside the cab  10 , but cab robustness may be compromised, so such an arrangement is typically not preferred. 
     A rear see-through panel  46  (e.g., a window or a screen) extends between the rear support posts  42  at upper portions thereof so as to provide the operator with rearward visibility. Similarly, a forward see-through panel (not shown) is provided between the forward support posts  40 . The forward and rearward see-through panels may also be kickout panels for emergency escape if desired. 
     The cab  10  may also include a conventional forward instrument panel  50  and forwardly positioned operator pedals  52 . The tractor  82  may also include a conventional steering wheel  51  (schematically represented in FIG. 1) for steering the tractor  82 . 
     A pivoting seat assembly  60  is located inside the cab  10  and generally includes an operator&#39;s seat  58  mounted to a pivoting floor structure  66 , which defines at least a portion of the floor of the cab and a cover for the under-cab components. The seat  58  can be of conventional design and may typically include a seat cushion, a seat back, arm rests, and seat belts. The seat  58  is attached atop a seat suspension  62 , which in turn is secured to the pivoting floor structure  66 , preferably on slidable seat-adjusting tracks (not shown). The seat may also include one or more control devices  64  (e.g., a joy-stick) for operating the tractor and/or tractor attachments. 
     In the illustrated embodiment, as shown in FIG. 4, the pivoting floor structure  66  includes a raised central portion  68  and a right side flange  70  and left side flange  72 . The raised central portion  68  may be configured to accommodate space requirements of undercab components and/or height requirements of the seat  58 . Alternatively, or in addition, the pivoting floor structure  66  may be constructed with folds and bends so as to increase the stiffness and rigidity of the structure. In the illustrated embodiment, the pivoting floor structure  66  is pivotally mounted by means of a hinge connection  74  connecting the right side flange  70  to mounting structure  75  that is connected to the cab footing structure  84 . During normal operation of the tractor, the pivoting floor structure  66  is in the down position as shown in FIGS. 1 and 4 and in phantom in FIG. 2, and the left side flange  72  is fixedly secured to the cab foot structure  84  by means of bolts  77 , or similar mechanical fasteners. Under such normal operation, the floor structure  66  defines at least a portion of the floor of the cab  10 . 
     To permit access to the under-cab components, such as the transmission  88 , the hydraulic cylinders  86 , or the U-joint/drive line component  90 , the forward doors  12  and  16  are opened, and the bolts holding the rear doors  24  and  28  closed at the respective locking brackets  25 ,  29  are removed, so that the rear doors  24  and  28  can be opened, as shown in FIG.  3 . Next, the bolts holding the floor structure  66  down are removed, so that the pivoting floor structure  66  and the seat  58  of the pivoting seat assembly  60  can pivot outwardly in the direction of arrow “A” as shown in FIG.  2 . 
     Although the pivoting seat assembly  60  can be actuated manually to pivot the seat  58  and floor structure  66  outwardly, it is preferred that a pivot assist mechanism, such as one or more gas spring cylinders  94 , be provided to assist in pivoting the seat assembly  60 . Alternatively, powered hydraulic or pneumatic cylinder systems can be employed, but such systems are not preferred because of the danger of inadvertent activation of the pivoting system. It is preferred that gas spring cylinders of sufficient size and lifting capacity be chosen, depending on the size and weight of the pivoting seat assembly  60 , so that when the bolts securing the left side flange  72  to the cab footing structure  84  are removed, the pivoting seat assembly  60  will slowly begin to rise. In this manner, to achieve the full pivot position, would only require a partial measure of manual assistance. 
     Cylinders  94  also partially support the weight of the pivoting seat assembly  60  when it is tilted back down to the cab footing structure  84  to prevent the assembly  60  from slamming into the cab footing structure  84 . In addition to bolts or other mechanical fasteners securing the left side flange  72  to the cab footing structure  84 , a safety latch (not shown) can be provided as a secondary means of holding the pivoting floor structure  66  down after the mechanical fasteners are removed. Such mechanical fasteners prevent the seat assembly  60  from “popping up” or avoid inadvertent pivoting and allow for the pivoting floor structure  66  to be held down when the bolts are being reinstalled to hold flange  72  to the cab footing structure  84 . 
     The pivoting seat assembly  60  is preferably pivoted so that the right and left flanges  70 ,  72  of the pivoting floor structure  66  are at least about 960 with respect to the cab footing structure  84  and frame  80 , so as to provide maximum access to the under-cab components. By rotating the pivoting seat assembly at least 900, the center of gravity of the assembly  60  will be over center, so that the assembly  60  will stay in the tilted position. A strap  92  or other hard stop structure can be provided to hold the pivoting seat assembly  60  in the outwardly pivoted position and to prevent over-rotation of the seat assembly  60 . 
     To accommodate the pivoting of a seat  58 , one or more control devices  64  with sufficient control line lengths should be provided. 
     With the doors open and the pivoting seat assembly  60  pivoted outwardly, convenient and ample access is provided to the under-cab components for both maintenance personnel and maintenance equipment. For example, a boom hoist (not shown) can be brought into the cab  10  beneath the roof structure  44  for lifting heavy undercab components (e.g., the transmission) out of the frame of the tractor for remote servicing. 
     Because the whole cab is not tilted, the structural integrity of the cab-frame connection as well as the stability of the tractor is maintained. The structure is robust and can be certified in accordance with SAE guidelines as a ROPS (Roll-Over Protective Structure), FOPS (Falling Object Protective Structure) and/or OPS (Operator Protective Structure). In addition, if one or more doors becomes damaged and inoperative, under-cab access according to the present invention can be regained by simply replacing or repairing the affected door(s). 
     Thus, the embodiments presented herein provide a novel work vehicle cab compartment that is configured to provide safe, convenient, and ample access to under-cab components. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments. On the contrary, modifications, variations, and equivalent arrangements are possible consistent with the above teachings or may be acquired from practice of the invention. As such, the scope of the invention is defined by the claims and their equivalents. 
     In this regard, while the cab compartment of the present invention has been described in accordance with a tractor vehicle, artisans of ordinary skill will readily appreciate that such a compartment may be applied with equal advantage to similar work vehicles. 
     Moreover, although the preferred embodiment teaches the cab compartment as configured with two doors on each side of the cab, one larger door may be provided on each side. Alternatively, the cab may include a single large door on one side and two doors on the other side of the cab. 
     Furthermore, while the pivoting floor structure  66  has been shown and described as a single pivoting structure, it may comprise more than one pivoting structure. For example, two opposed pivoting panels, one supporting the seat, may be installed so as to pivot in opposite directions to provide an access opening to the under-cab components.