Abstract:
A set of panel assemblies for enclosing the overhead guard of a vehicle such as a skid steer comprising a windshield/door assembly and side window assemblies. The windshield/door assembly includes a door jamb that is clamped over the front corner posts of the overhead guard and a windshield/door unit hinged on the jamb. The windshield/door unit seals against a generally planar front face of the jamb. The side window assemblies comprise transparent rigid plastic sheets adapted to be attached to the side grille of the overhead guard in a simplified manner and without occupying excessive space in the clearance area between the overhead guard and operating elements such as the lift arms of a bucket.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to cabs for land vehicles and, more particularly, to a cab construction for use with vehicles having an existing overhead guard. 
     PRIOR ART 
     Severe weather and other environmental conditions can create a need for a fully enclosed cab to protect the operator of a tractor or like machine. Frequently, a tractor is originally built with an overhead guard to provide roll over protection and/or protection from falling objects. U.S. Pat. No. 5,286,081 discloses a cab construction that successfully solves problems attendant with providing a serviceable and cost effective cab structure for certain types of machinery. 
     An increasingly popular style of tractor is the skid steer loader, hereinafter skid steer, which affords high maneuverability enabling it to be operated in relatively small areas. These skid steers typically have an operator seat in a forward position to provide a view immediately in front of the machine. Also typical of skid steer designs is the location of the lift arms for carrying and lifting a material handling bucket or other implement. The arms extend longitudinally of the machine on both sides of and immediately adjacent the operator station. To ensure against an operator inadvertently extending a hand or limb to the side and into the path of the lift arms, the operator station is equipped with side guards. Normally, the side guards are in the form of a grille that permits vision to the side but prevents extension of a hand or limb to the side. The side grilles generally are fixed to the overhead guard that is part of the original equipment. As a design criteria, a skid steer is a compact machine where little space or clearance is afforded between parts. This characteristic presents difficulties in fitting such a machine with a windshield or side windows. 
     Besides being economical to construct and easy to install, a cab enclosure should be simple and easy to remove and reinstall where it is used, for example, to protect the operator during seasonal periods only, such as during winter months. 
     SUMMARY OF THE INVENTION 
     The invention provides a panel arrangement for enclosing the operator station cab of a vehicle that as originally manufactured includes an overhead guard. More specifically, the disclosed panel arrangement can include a combination door and windshield assembly for ingress and egress to the operator station and side window panels for sealing other areas surrounding the operator station. The windshield/door front panel assembly incudes a base panel door jamb that frames the door opening and is adapted to carry a swingable door on associated hinges. The door jamb panel presents a planar face that surrounds the door opening. The door has a peripheral seal, ideally, in the form of an elastomeric weatherstrip that reliably fully contacts the planar surface of the door jamb panel. Preferably, the door is hinged and configured to open with a simple outwardly swinging motion avoiding interference with the original standard parts of the vehicle. 
     On a typical skid steer the door jamb panel can be configured to lay over the front corner post of the overhead guard and to laterally engage these posts between a pair of integral opposed flanges disposed on the side faces of the posts. The door jamb panel is locked to the corner posts by a plurality of clips bolted or other otherwise secured to the panel plate and interlocking with the corner posts. 
     Cab side window panels constructed in accordance with the invention take advantage of the existing rigid grille side walls customarily found on the overhead guard of a skid steer. In effect, the side panels of the invention utilize the guard as a support structure thereby avoiding the need to provide the side panels with a separate frame. The side panels, made of clear transparent sheet stock material, are secured to the side grilles with a plurality of screws or like fasteners set into individual blocks extending on the inside face of the grille at strategic locations across the expanse of the side panels. The blocks are proportioned to ensure that the side panel sheets are drawn sufficiently tight against the grille to compress a weatherstrip sealing bead adjacent the perimeter of the panels. The disclosed mounting arrangement provides an adequate seal between the panels and overhead guard and, additionally, provide a simple mounting arrangement that takes up relatively small space in the limited clearance area between the sides of the overhead guard and the lift arms. Moreover, the unique mounting blocks enable the panels to be mounted by a single workman working from the outside of the cab. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective, somewhat schematic, view of a skid steer vehicle fitted with the cab enclosure panels of the invention; 
     FIG. 2 is a front view of the skid steer with the windshield/door unit in an open position; 
     FIG. 3 is a cross-sectional view taken in a horizontal plane indicated by the arrows  3 — 3  in FIG. 1 of the front part of the overhead guard of the vehicle and the windshield/door unit; 
     FIG. 4 is a fragmentary perspective view of a hinge for the windshield door unit; 
     FIG. 5 is a fragmentary cross-sectional view taken in the vertical plane indicated by the arrows  5 — 5  in FIG. 2 of a portion of the vehicle and a door jamb panel assembly of the invention; 
     FIG. 6 is a side view of a transparent sheet of a side window panel assembly; 
     FIG. 7 is a view of a typical block for securing a  12  side window assembly to the side grille of the overhead guard; and 
     FIG. 8 is a fragmentary cross-sectional view taken in a vertical plane showing a typical installation of a side window panel on a side grille of the overhead guard. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, there is shown a land vehicle  10  in the form of a skid steer loader, referred to as a skid steer herein. The skid steer is generally conventional in overall layout having a fabricated steel chassis  11 , a set of four wheels  12 , and a motor, not shown, adjacent the rear of the vehicle. The illustrated skid steer  10  has a pair of spaced lift arms  13  on opposite sides of the chassis  11 , operated by hydraulic piston and cylinder actuators  14 . The arms  13  lift a bucket  16  or other working implement at the front of the skid steer  10 . 
     A person operating the skid steer  10  sits in a seat  17  in an operator&#39;s station generally indicated at  18 . The operator station  18  is surrounded by an overhead guard  19  that has four generally upright corners, the front corners or corner posts being designated by the numeral  21  and the rear corner or corner posts being designated by the numeral  22 . The corner posts  21 ,  22  generally form the boundaries of the front, sides and rear faces of the overhead guard  19 . The rear face of the guard is typically closed by a steel panel and/or a type of safety glass. The front face of the guard  19 , as it is originally manufactured for the skid steer  10 , is open to allow the operator to enter and exit. 
     At each side, the overhead guard  19  has a rigid grille  23  with sufficient openings  26  throughout its expanse to permit the operator to see through it in order to afford an adequate view of the surrounding field. In the illustrated case, the grilles  23  are formed by cutting rhomboid shaped openings or apertures  26  in a heavy gauge steel sheet  24 . The openings  26  leave an integral network or matrix  27  of intersecting steel strips. The remaining steel network  27 , after the holes  26  have been cut is effective to prevent an operator from inadvertently extending his hand or arm outward beyond the plane of the side grille or guard  23  into the operating path of a lift arm  13 . Other grille constructions, such as a welded wire mesh are contemplated. 
     The front corner posts  21  are efficiently made by breaking non-apertured areas of the steel sheet forming the side grille  23  into a U-section  28  as shown in FIG.  3 . Alternate corner post constructions are contemplated such as rectangular steel tubes welded to a side wall grille. The corner posts  21  and  22  support a steel sheet  29  forming the roof of the overhead guard in a conventional manner. The lower ends of the corner posts extend down and are supported on the chassis  11 . The overhead guard  19  may be pivotally mounted at the rear corner posts to allow it to be swung upwardly and rearwardly for access to the drive train and other parts of the skid steer in a conventional manner. Where the overhead guard  19  is counter-balanced in this pivoting action by gas springs or other conventional devices it is desirable that accessory parts such as the protective panels of the invention to be described hereinbelow are of lightweight construction so as to avoid re-engineering of the factory supplied cab counter-balancing springs. 
     The above-described skid steer construction details are similar if not the same, in the products of various skid steer manufacturers. The overhead guard serves to protect the operator in a roll-over or from falling objects as well as to laterally confine his limbs so as to prevent their inadvertent extension into the path of the side lift arm mechanisms. 
     The invention provides a front panel assembly  31  that serves as a windshield and door and side panel assemblies  32  to enclose the space within the overhead guard  19  and thereby protect the operator from severe weather or other adverse conditions such as a dusty environment. 
     The front panel assembly  31  includes a base panel  33  that serves as a jamb for a door assembly  34 . The door jamb base  33  is preferably fabricated of sheet steel and, in the illustrated case, is in the form of a generally rectangular continuous outline having a large generally rectangular cutout  35 . The door jamb panel or base  33  has integral sides  36 , header  37 , and threshold  40 . The generally vertical sides  36  of the door jamb  33  have integral flanges  38  bent perpendicularly rearwardly to the plane of a front face  39  of the major part of the door jamb. When installed on the overhead guard  19 , this front planar face  39  is generally upright and slopes somewhat to the rear to conform to the slight inclination of the front corner posts  21 . The flanges  38  are spaced from one another so that they fit closely over respective ones of the corner posts  21  of the overhead guard  19 . More specifically, the flanges  38  overlie faces  41  of the corner posts  21  on the sides of the overhead guard. A sheet metal angle  42  forms a threshold for the door opening or cutout  35  and, as is shown in FIG. 5, is formed to seat on a cross member  43  of the skid steer chassis  11 . A plurality of bolts  44  lock the door jamb  33  and threshold angle  42  together. With a flange of the threshold angle  42  resting on the cross member  43 , the angle vertically supports the door jamb on the chassis  11 . Upper portions of the door jamb  33  are removably fixed to the overhead guard  19  by J-shaped clips  47  located at a plurality of points along the length of the corner posts  21 . The clips  47  are locked in position by bolts  48  that extend through holes  49  vertically spaced on the vertical sides of the door jamb  33 . Study of FIG. 3 reveals that the door jamb  33  is laterally located and locked in position on the overhead guard by the integral flanges  38  which abut or nearly abut the side faces  41  of the corner posts  21 . The door jamb  33  is locked against forward or rearward movement by the action of J-clips  47  which capture the corner posts  21  between retaining portions  51  of these clips and rear surface areas  52  of the door jamb plate  33 . It will be understood that the door jamb  33  is thus releasably mounted to the overhead guard  19  and, particularly, to the front corner posts of the guard by surface areas of the jamb  33  and clips  47  which prevent any relative movement between the jamb and the corner posts but do not structurally alter the corner posts. In the preferred embodiment, the clips  49  at each side of the jamb  33  are relatively short in their vertical dimension, for example, being 1-½″ tall. It is contemplated that the several clips at each side can be replaced by a continuous clip having a length comparable to the full length of a corner post. 
     The door assembly  34  is fabricated from steel sheet stock and includes a pair of sheets  56 ,  57  which are generally rectangular in their front profiles and have large cutouts for a windshield  58 . An outer one of the sheets  57  has its edges bent outwardly to form a peripheral flange  59  for stiffening purposes. The sheets  56  and  57  are welded together at appropriate points to form a rigid structure. The windshield  58 , made of safety glass, is carried on the inner one of the sheets  56  through the use of a conventional elastomeric mounting piece  61  along the perimeter of the glass, as is conventional. The door assembly  34  is hinged on one side of the door jamb  33  and is latched on the opposite side of the jamb. The hinge arrangement can comprise a pair of hinges  62 . Portions  63  of the hinges  62  associated with the door jamb  33  can be welded directly to the door jamb. Mating portions  64  of the hinges  62  can be bolted to the door assembly  34 ; slots or oversize holes in the door allow the door to be adjusted for a proper fit with the latch on the opposite side. The latch, indicated at  67  is a commercially available unit that is hand-operated from either the inside or outside of the guard  19 . A top  70  of the door jamb plate  33  lies below the plane of the underside of the overhead guard roof plate. 
     The periphery of the door sheet  56  is fitted with a commercially available elastomeric weatherstrip  71 . The weatherstrip  71  includes an integral channel  72  which grips the peripheral edge of the sheet  56  and a hollow bulb  73  which permits the weatherstrip to compress so that it can seal surfaces which are not precisely parallel or planar in a known manner. It will be seen that the weatherstrip  71  is compressed and seals against the outer surface of the door jamb  33  which, as described, is substantially planar. The weatherstrip  71  has sufficient compliance, due to the bulb  73 , to accommodate a slight offset of the lower threshold area of the door jamb  33  which projects slightly outwardly, as shown in FIG.  5 . FIG. 3 shows the door assembly  34  in the closed position against the door jamb  33 . 
     Optionally used with the front panel assembly  31  are the pair of side panel or side window assemblies  32 . The side window assemblies  32  are in the form of left and right units that are mirror images of one another. Each side window assembly  32  includes a transparent sheet  77  preferably of a thermoplastic material such as polycarbonate or polyvinyl chloride or a suitable glass such as laminated safety glass or a tempered glass. The illustrated side window sheet is made of ⅛″ or ¼″ polycarbonate. The outline of a sheet  77  is cut in accordance with a boundary surrounding the side grille  23  so that its edges lie on those parts of the steel sheet  24  surrounding the grille  23 . The typical skid steer has a generally planar boundary formed by parts of the overhead guard sides surrounding the grille or mesh protector. In instances where a side surface is not planar, suitable filler pieces can be provided to create a planar surface against which a side window assembly can seal. Alternatively, the side window assemblies can be non-planar to match the guard configuration. The side window assembly includes a weatherstrip  78 , such as described in connection with the door assembly  34 , fitted on the periphery of the window sheet  77 . The side window assemblies  32  are releasably mounted on the overhead guard  19  with a series of identical mounting blocks  79 . The mounting blocks or clips  79  in the illustrated example are square or rectangular units including a main body  81  and a flange forming plate  82 . The illustrated main body and flange plate are steel pieces welded together. The main body  81  has a tapped hole  83  in its central region perpendicular to the plane of the flange plate. A plurality of mounting blocks are assembled on the window sheet  77  generally along but spaced inwardly of its periphery. The mounting blocks are retained on the sheet  77  by screws  84  assembled through holes  86  strategically located in the sheet  79 . The holes  86  are located on the sheet  77  so that the mounting blocks  79  are registered with selected holes  26  provided by the grille or network  27 . It will be understood that the flange plate or major profile of the mounting block or clip  79  is arranged to pass through its respective hole  26  when the block has a certain angular orientation about the axis of its screw  84  and hole  86 . It will be understood that all of the mounting blocks  79  can be moderately tightened with their respective screws  86  against the window sheet  79  prior to mounting of the window assembly  32  on its respective overhead guard side grille  23 . A workman can then install the window assembly  32  on the guard side grille  23  by tightening successive ones of the screws  86 . Initial tightening movement of a screw  86  will rotate the block  79  so that the block is no longer oriented with the rectangular or rhomboidal pattern of its associated hole  26  and, consequently, the block and adjacent portion of the side window is fixed to the side grille  23 . The blocks  79  are proportioned to moderately compress the weatherstrip bulb  73  against the side sheet  24  when the mounting block flange plate or tab  82  is in contact with the inside surface of the side sheet  24  (FIG.  8 ). To summarize, the mounting block in its original orientation for installation can pass freely through the associated grille hole  26  but when the screw  86  is thereafter tightened, the mounting block rotates a limited degree so that the flange plate is misaligned with the hole and cannot pass freely back out through such hole. The main body  81  is proportioned so that the mounting block cannot rotate through an angle approaching 90°. It will be understood that the side window assemblies can be installed by a single mechanic working comfortably outside of the overhead guard  19 . The blocks  79  or their equivalents can be extruded or molded of suitable metal or plastic material. 
     From the foregoing description, it will be understood that the front panel assembly  31  and side panel assemblies  32  are capable of being proportioned to fit various skid steer units manufactured by different companies. The front and side panel assemblies, are readily installed and removed as desired from season to season or job to job. Moreover, the side panel assemblies can be used without the front panel assembly and vice versa depending on the operator&#39;s preference. 
     It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.