Abstract:
A system, particularly suited for after market applications, for enclosing an overhead guard with window and prehung door assemblies. The window and door assemblies are arranged with portions that overlie outer surfaces of the guard and portions engageable with inner surfaces of the guard to retain the respective assemblies in place on the guard. The retaining structure of each of the assemblies extends through original vision or ingress/egress openings in the guard so that installation is simplified and structural alteration of the guard is avoided.

Description:
The invention relates to cabs for off road land vehicles to protect the driver from adverse environmental conditions. 
     PRIOR ART 
     Land vehicles such as lift trucks, construction machinery, farm machinery and the like are frequently supplied with a cab enclosure to protect the driver or operator from severe weather, dust, noise or other environmental conditions. For reasons of cost and/or other factors, a vehicle may be originally manufactured without a fully enclosed cab. In many product lines, a vehicle may be manufactured and delivered to a dealer or end user with a factory built overhead guard. Such guards typically comprise an open framework or network fabricated from sheet stock, tubing and/or other structural steel shapes. It is known for a manufacturer to produce an overhead guard with sheet metal flanges that can be glazed with safety glass or shatter resistant plastic to form a windshield, side lights, and/or rear window in the event that a customer desires an enclosed cab. These glazing flanges, integrated with the factory installed overhead guard, are intended to allow glazing to be fitted at the factory or to facilitate dealer installation of the glazing panels. This approach of integrating glazing flanges with a guard, in theory, offers flexibility in meeting customer&#39;s demands. However, dealer installation of glazing may be troublesome because the available personnel may be inexperienced and ill-equipped to perform the necessary tasks. 
     SUMMARY OF THE INVENTION 
     The invention provides glazing assemblies particularly suited for dealer or after market installation on factory built overhead guards, particularly those originally manufactured with glazing flanges but originally sold without glazing. The glazing assemblies of the invention include conventional safety glass or shatter resistant plastic glazing and a rigid metal frame surrounding the perimeter of the glazing. 
     The glazing assemblies are arranged to span the openings in the overhead guard structure. As disclosed, the assemblies are retained on the cab with structural elements that extend through the planes of the original factory glazing flanges to enable the assembles to be mechanically clamped on the guard. 
     In accordance with another aspect of the invention, the ingress and egress areas of the guard are enclosed by prehung door assemblies. The disclosed door assemblies include a door jamb proportioned to fit onto strategic parts of the overhead guard. A door is hinge-mounted on the specially configured jamb. In a manner similar to the glazing assemblies, the door assemblies are clamped onto the original overhead guard structure. The disclosed glazing and door assemblies can be installed with personnel having no glazing experience with minimal instructional time and with little chance of error. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a large lift truck having an overhead guard to which the present invention has been applied; 
     FIG. 2 is a rear perspective view of the lift truck and overhead guard to which the invention has been applied; 
     FIG. 3 is a somewhat schematic exploded perspective view of the overhead guard and the glazing assemblies and prehung door assemblies of the invention; 
     FIG. 4 is a fragmentary cross-sectional view of a front corner or port window area of the overhead guard and an associated glazing assembly taken in the plane  4 — 4  indicated in FIG. 1; 
     FIG. 4A is a fragmentary cross-sectional view of the front port window assembly taken in the plane  4 A— 4 A indicated in FIG. 4; 
     FIG. 4B is a fragmentary cross-sectional view of the front port window assembly taken in the plane  4 B— 4 B indicated in FIG. 4; 
     FIG. 5 is a fragmentary cross-sectional view of a front windshield assembly taken in the plane  5 — 5  indicated in FIG. 1; 
     FIG. 5A is a fragmentary cross-sectional view of the front window assembly taken in the plane  5 A— 5 A indicated in FIG. 1; 
     FIG. 6 is a fragmentary cross-sectional view of a rear window assembly taken in the plane  6 — 6  indicated in FIG. 1; 
     FIG. 7 is a fragmentary cross-sectional view of the rear window assembly taken in the plane  7 — 7  indicated in FIG. 2; 
     FIG. 8 is a fragmentary cross-sectional view of the rear window assembly taken in the plane  8 — 8  indicated in FIG. 2; 
     FIG. 9 is a cross-sectional view of a roof area of the overhead guard and an upper part of a prehung door assembly of the invention taken in the plane  9 — 9  indicated in FIG. 1; 
     FIG. 10 is a cross-sectional view of the threshold area of the prehung door in the plane  10 — 10  indicated in FIG. 1; and 
     FIG. 11 is a fragmentary cross-sectional view of a side of the overhead guard, side window assembly, prehung door assembly, and rear window assembly taken in the plane  11 — 11  shown in FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the figures and, in particular to FIGS. 1 and 2, there is shown an off highway land vehicle in the form of a large lift truck  10 . A chassis  11  of the lift truck  10  has front wheels  12  and rear wheels  13 . An engine and transmission (not shown) are mounted on the chassis to propel the truck  10  through the front wheels  12  in a conventional manner. Mounted on the chassis  11  is a factory installed overhead guard  14  most clearly shown in FIG.  3 . The present invention is useful for situations where an original guard is shipped from the factory without glazing or doors and it is desired at a dealer or ultimate user level that the guard be fitted with windows and doors to provide a fully enclosed cab. The overhead guard  14  illustrated in FIG. 3 somewhat schematically illustrates a Hyster Lift Truck Model Series H 165XL/210XL. It will be understood from the present disclosure that the invention is applicable to other land vehicles and like machinery. The illustrated overhead guard  14  is of a type intended to be optionally fitted with safety glass or other suitable glazing. To this end, front, side and rear faces  16 ,  17  and  18 , of the guard  14  have window openings  21 ,  22  and  23  bounded by flat sheet metal structure or flanges. 
     The overhead guard  14  is typically fabricated of structural steel elements. The front, side and rear faces  16 ,  17  and  18  of the guard are generally vertical. At or near the intersections of the front, sides and rear faces, the guard has four generally vertical post structures  24 ,  25  that support a generally horizontal roof  19 . The boundaries of the front and side window openings  21 ,  22  are each planar and are formed by sheet steel of a moderate gauge of about {fraction (3/16)} inch, for example. The boundary of the rear window  23  is similar in character except that it has a wrap around design that comprises a planar back portion bounded at its top and bottom by flat sheet stock and planar side portions generally at right angles to the back portion and each bounded at its top, forward side, and bottom edges by planar sheet stock. As with the front of the guard, the rear parts of the guard bounding the rear window  23  can have a moderate gauge of about {fraction (3/16)} inch, for example. 
     At the sides  17  of the guard  14  between the front side port window openings  22  and side portions of the rear window opening  23  are large, rectangular openings  26  for access and egress of the operator to and from an operator&#39;s station or driver&#39;s seat within the guard. 
     A front windshield assembly  31  for closing the front window area or opening  21  of the guard  14 , constructed in accordance with the invention, comprises a rigid perimeter frame  32  and safety glazing  42 ,  43 . (For clarity, the glazing panels or sheets are omitted in the illustration of FIG. 3.) The frame  32  is generally planar and has a generally rectangular configuration corresponding to the shape of the front window area  21 . Preferably, the frame  32  is fabricated primarily of sheet steel but can be made of other suitable materials such as aluminum or plastic. The outside dimensions of the frame  32  are slightly larger in both the vertical and horizontal directions than corresponding dimensions of the window opening  21  and the frame has openings  34 ,  36  which collectively are smaller than the corresponding dimensions of the window opening or area  21 . With this configuration, top, side and bottom elements  37 ,  38  and  39  of the perimeter frame  32  when installed on the guard  14  each cover a marginal part of adjacent underlying surfaces of the guard front face  16  at the window opening  21  and a peripheral part of the window opening itself. In the illustrated construction, the frame  32  includes a muntin or bar  41  dividing the areas forming the upper and lower openings or lights  34 ,  36 . The upper main light or opening  34  is preferably glazed with laminated safety glass  42  and the lower light or opening  36  is preferably glazed with clear polycarbonate sheet stock  43  or other suitable shatter-resistant plastic. Both glazing sheets  42 ,  43  are preferably mounted on the sheet stock of the frame  32  with extruded rubber strips  44 , known in the art. 
     The windshield assembly  31  is retained on the guard  14  with mechanical fastening elements that extend through the original window opening  21  thereby avoiding structural alteration of the guard  14  and possible compromise of its integrity. In the illustrated example, these fastening elements include a lower Z-strip  46  (FIG. 5) and machine screws  47  (e.g. FIG.  5 A). The Z-strip  46  which is welded or otherwise fixed to the frame  32  hooks over the lower edge of the window opening  21  to grasp the guard  14  at this location. The screws  47  located at spaced locations around the perimeter of the window opening  21  engage threaded holes in associated clamp plates  48 ,  49  and  50  positioned within the guard  14 . As shown for example in FIG. 5A, the clamp plates  49 ,  48  are each proportioned to receive its associated screw  47  at a location within the boundary of the window opening  21  and to bear against the inside face of the guard flange surrounding the window opening. Spacers  53  such as typically shown in FIG. 5A can be provided between the clamp plates  48 - 50  to generally align the associated clamp plate in parallel relation to the part of the guard structure it clamps against. The spacers  53  are preferably welded to the frame  32 . The threaded holes of the clamp plates  48 - 50  can be provided by weld nuts as shown. 
     The glazing sheets  42 ,  43  are preferably factory mounted on the frame  32  preferably at the factory where the window assembly is made and thus before the windshield assembly  31  is installed on the guard  14 . Installation of the assembly  31  is facilitated by the Z-strip  46  which, when hooked over the lower edge of the window opening  21  is capable of supporting the weight of the assembly while the retaining screws  47  are assembled through clearance holes  54  in the frame  32 , registered with associated clamp plates  48 - 50  and finally tightened into such clamp plates. FIG. 5A shows typical details of the arrangement of a retaining bolt or screw  47  and a clamp plate  49  at points spaced around the perimeter of the window opening  21 . 
     A front side port window assembly  56  includes a generally triangular perimeter frame  57  fabricated from steel sheet stock and safety glazing  58  in the form of clear polycarbonate or other suitable shatter-resistant glazing sheet material. Like the front windshield assembly  31 , the outside dimensions of the frame  57  are larger than corresponding dimensions of an associated side port opening  22  and the inside dimensions are smaller than the corresponding dimensions of such opening. In the installed condition, the frame  57  abuts the outside surface of the guard  14  surrounding the port opening  22  and the glazing fits within this opening. The frame  57  is held in place by a lower clamp plate  59  and an upper clamp plate  61  positioned against the inside surface of the guard below and above the glazing  58 . The frame  57  is held against the guard by tightening machine screws  62  assembled through holes  63  in the frame into respective ones of the clamp plates  59 ,  61 . Again, like the windshield assembly  31 , the frame  57  is proportioned so that the screw receiving holes  63  are within the boundary of the side port opening  22  so that the need for cutting or drilling holes in the guard or other like alteration is avoided. The glazing  58  is held in place against the inner face of the frame  57  by machine screws  66  assembled through aligned holes in these members within the boundary of the side port opening  22  and tightened into nuts  69  on the inside face of the glazing  58 . 
     A rear windshield assembly  71  comprises a rigid frame  72  and glazing units  85 ,  88  and  89 . The frame  72 , in the illustrated example, is fabricated from steel sheet stock having cutouts or openings  77 ,  78  and  79  (FIG. 3) for rear and rear side vision. The frame  72  has a generally planar rear section  81  including the two large cutouts  77 ,  78  and two side sections  82  formed by bending the sheet into a U-shape or wrap around configuration. The side sections  82  include the side port cutouts  79 . A rightward one  77  of the large cutouts is fitted with laminated safety glass  85  or other suitable glazing mounted in a conventional elastomeric extrusion. The other large cutout  78  is fitted with a double-hung window frame  88  carrying suitable safety glazing. This double-hung frame  88  is mounted in the cut-out  78  with suitable elastomeric extrusion material known in the art. A vertical reinforcing bar or mullion  83  is welded to a central part of the rear section  81 . A Z-strip  84  is welded on the inside lower margin of the rear section  81  to form an inverted channel. Glazing units  89  of polycarbonate or other suitable shatter-resistant glazing material are attached to the side sections  82  of the frame  72  over the side port openings  79  by machine screws  86  or other suitable known fastening medium. 
     The Z-strip  84  is positioned so that it can be hooked over the lower edge of the rear window area  23  to thereby support the weight of the assembly  71  as it is being installed on the guard. The assembly  71  is retained on the guard  14  in a manner like that of the front windshield assembly  31 . The perimeter elements of the frame  72  surrounding the cutouts  77 - 79  overlie portions of the guard surrounding the rear opening  23  and adjacent areas within the boundary of the opening. Machine screws  87  are assembled through holes spaced along the perimeter of the frame  72  and pass through areas of the rear opening  23  and are tightened into retaining plates  91 ,  92  and  93  positioned on the inside of the guard. The plates  91 - 93  bear against the inside surfaces of the guard so that when the screws  86  are fully tightened, the frame  72  is securely held in place on the outside of the guard. Again, as with previously described window assemblies  31 ,  56  no structural modification of the guard is required for mounting the rear windshield assembly  71 . 
     The guard  14  is fitted with generally symmetrical right and left hand door assemblies  96 . In accordance with the invention, the door assemblies  96  each comprise a door  97  “pre-hung” on a door frame  98 . In the construction illustrated, the door frame  98  is a rectangular steel framework including jambs  101 , a header  102  and a threshold  103  all welded or otherwise joined rigidly together. Preferably, the frame members  101 - 103  include outer flanges  104  generally coplanar with each other and adapted to abut the outer face area of the guard  14  surrounding the passage opening  26 . The door  97  is pivotally mounted to a rearward one of the jambs  101  with a continuous hinge  106 . A conventional door latch assembly generally indicated at  107  releasably holds a door closed in the frame  98 . Each door assembly  96  is secured in place in the opening  26  by a plurality of retaining bolts  111  and bracket elements  112  located at vertically spaced locations on the jambs  101 . The retaining bolts or screws  111  are threaded into internally threaded bosses  113  welded onto the jambs  101 . The brackets  112  are arranged, when the bolts  111  are tightened to bear against inside surfaces of the guard to draw the flanges  104  of the jambs  101  against the outer surfaces of the guard. It will be understood from the foregoing that the door assemblies  96  are secured in place on the guard  14  by clamping elements  111 ,  112  that develop a grip on both faces of the sides of the guard  14  without requiring structural modification of the guard. The roof  19  of the guard can be partially covered with a transparent glazing sheet fitted over the roof opening  115  to enclose this area of the guard. 
     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.