Abstract:
An elevator cab constructed in-situ from elongated channel shaped pans. The pans have their ends bolted to steel alignment angles and their flanges bolted to abutting flanges of adjacent pans. The pans and alignment angles can be bolted together with bolts and nuts of a common size and preferably are arranged to rotationally interlock with the bolts to simplify tightening of the nuts and enable the cab to be conveniently assembled even in low clearance hoistways. Light fixtures are nested in associated pans forming the cab top and are protected by sheet metal panels secured to the flanges of such pans. An emergency exit door on a top panel has a unique safety switch interlock.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The invention relates to elevator cab construction and, in particular, to cabs of the type assembled from a plurality of steel panels.  
         PRIOR ART  
         [0002]    Elevator cabs or cars are typically erected within a hoistway or shaft because ordinarily the landing openings to the shaft are roughed in or finished before the car is on site and because the openings are smaller than the size of the cab. It is a common practice to construct the cab of sheet metal panels small enough to be easily passed through a landing opening. Various structural designs have been developed for in-situ erection of a cab. These designs may have a structural steel skeletal framework or may rely on the panels themselves for requisite strength and stiffness. Where the space in a hoistway is limited in relation to the size of the cab, it may be difficult and time consuming to assemble prior art cabs. More specifically, there may be very limited space between the walls of the hoistway and the walls of the cab making it difficult to obtain comfortable access or to manipulate wrenches or other tools. Such tight quarters, additionally, can make it difficult or impossible to gain a clear line of sight where parts or fasteners need to be aligned and assembled.  
         SUMMARY OF THE INVENTION  
         [0003]    The invention provides an elevator cab construction that is economical to fabricate, simple and quick to install and rugged in service. The cab construction involves a unique combination of elements that can be readily assembled by a workman even without previous experience and without extraordinary skill or dexterity and yet obtains a rugged unit with a quality fit. The basic elements of the cab are a plurality of elongated steel pans that, assembled together, make up the sidewalls and top of the cab. The panels are conveniently and correctly aligned with steel angles located at both of their ends.  
           [0004]    The alignment angles are factory formed with holes for fasteners that join the angles and panels together. A feature of the cab construction is an arrangement by which the various panels and angles of the cab are adapted to accept identical fasteners in both panel-to-panel joints and panel-to-angle joints. This feature simplifies the job of the installer since only one supply of fasteners need be carried and a single size wrench can be used to effectuate assembly of the cab.  
           [0005]    A further enhancement of the common fastener feature is the provision of accircular holes in the form of squares or slots in both the pans and the angles and the use of carriage bolts or like bolts dimensioned to rotationally interlock with the accircular holes. This combination enables the bolts to be tightened with a single wrench without difficulty and avoids the need to use both hands to accomplish the same. Where clearances between the cab and walls of the hoistway are close, the ability to complete the bolt tightening process with one hand can be a significant advantage.  
           [0006]    Steel alignment angles are used to set the location of the cab walls on an elevator platform. This ensures that the walls are erected along straight, parallel or perpendicular lines. These platform or bottom angles have precisely located factory formed holes for joining the wall panels in an error free manner. Preferably, the angles are mounted on the platform by first positioning them in a specified location, temporarily holding them in this position and drilling and tapping them in-situ simultaneously with the platform. Ideally, this is accomplished with self-tapping bolts. The described technique eliminates a troublesome need to correlate mounting holes in the platform, which is ordinarily built by a manufacturer other than the cab supplier, with holes in the bottom alignment angles of the cab.  
           [0007]    The disclosed cab can be advantageously erected by a workman standing or otherwise supported on the elevator platform essentially within the space being enclosed by the cab or on top of the cab. Thus, the assembly process is substantially unhindered by relatively close clearances between the cab and the hoistway.  
           [0008]    The various panels that make up the cab have a simple C-channel geometry that is inexpensive to fabricate, rugged enough to avoid damage in shipping, handling and expected service conditions and strong enough in service to avoid the need for a separate skeletal framework. A simple numbering system of the panels can be followed to ensure a fast, mistake proof assembly of the cab. The top panels of the cab have a deep section that lends itself to a readily protected recessed lighting system. An emergency exit door in a top panel has a safety switch arrangement that is wholly insensitive to panel distortion, misalignment, and moderate damage. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an isometric view of a cab constructed in accordance with the invention on a platform and with a small portion of a side pan broken away to reveal part of a bottom alignment angle;  
         [0010]    [0010]FIG. 2 is a fragmentary isometric view of a right bottom alignment angle and a typical bolt used to assemble these elements together;  
         [0011]    [0011]FIG. 3 is a fragmentary isometric detail view of the intersection of the right bottom angle and a rear bottom angle;  
         [0012]    [0012]FIG. 4 is an isometric view of a right rear corner of the cab being formed by intersecting wall pans;  
         [0013]    [0013]FIG. 5 is an isometric view of the assembly of the sidewall pans of the cab;  
         [0014]    [0014]FIG. 6 is a fragmentary exploded view of the assembly of a typical top alignment angle and side pans;  
         [0015]    [0015]FIG. 7 is a fragmentary exploded view of portions of a top pan being assembled to a top angle;  
         [0016]    [0016]FIG. 8 is a fragmentary cross-sectional view of top pans, a light fixture and a protective panel taken in the plane indicated at  8 - 8  in FIG. 1; and  
         [0017]    [0017]FIG. 9 is an isometric view of an emergency exit door and a safety switch. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    [0018]FIG. 1 illustrates an elevator cab or car  10  constructed in accordance with the invention. The cab  10  is assembled on a conventional platform  11  usually supplied by the source of the lift mechanism, typically a hydraulic cylinder below the platform or an electric hoist at the top of a hoistway or shaft as is known in the industry. The cab  10  is formed primarily of elongated pans or panels B 1 - 6 , R 1 - 5 , L 1 - 5  and T 1 - 5  with C-shaped channel cross-sections and steel angle pieces BA 1 - 3  and TA 1 - 3  that serve to align and interconnect the panels.  
         [0019]    The lengths of the three sets of angles BA, TA, determined at the cab factory or shop, correspond to the inside plan dimensions of the cab  10 . FIG. 3 illustrates how a bottom side angle BA 1  interfits with a rear bottom angle BA 2 . Another side bottom angle BA 3  interfits with the rear or back bottom angle BA 2  in the same way. The angles BA 1 - 3  are formed with accircular holes  16 , such as the illustrated square holes, at the cab factory. It will be seen that the location of the holes  16  corresponds to the eventual location of mating holes in the side panels B, R and L.  
         [0020]    With reference to FIG. 4, the bottom or platform angles BA 1 - 3  are properly located on the platform  11  with appropriate measurements being made and are preferably held temporarily in place by clamps or other suitable means. Once the angles BA 1 - 3  are temporarily fixed in position, self-tapping bolts  17 , known in the trade, are driven into lower horizontally extending legs  18  of the angles and the underlying platform  11  (FIG. 2). Undersize holes for receiving the bolts  17  can first be drilled in situ through the angle legs  18  and the platform  11 , if desired or necessary, for reception of the bolts  17 . These operations can be performed by the workman installing the cab exclusively from the topside of the platform  11 . Since the bolts  17  are spotted after the angles BA are properly located, there is no critical correlation of holes in the platform  11  and holes in the angles BA.  
         [0021]    The angles BA 1 - 3  serve to align the bottoms of the side panels B, R, L along straight lines and rigidly fix them to the platform  11 .  
         [0022]    The side and top pans B, R, L and T are preferably formed of steel sheets of, for example, 14 gauge stock painted after their fabrication into pans of C-shaped cross-section. The pans B, R, L and T are economically formed in a press brake, for example, and include flanges or legs  21 ,  22  and returns or lips  23 ,  24 . The pans B, R, L, T, preferably have a nominal width of, for example, about 18″ or similar dimension so that they are comfortably spanned by the arm of a workman to enable them to be bolted together. The pans B, R, L, T have factory or shop made accircular holes, in the form of oblong slots  26  spaced along their flanges  21 ,  22  and adjacent their end edges.  
         [0023]    [0023]FIG. 4 illustrates the initial steps in assembling the side pans B 1 , R 1  to the bottom platform angles BA 2 , BA 1 , respectively.  
         [0024]    The pans B 1 , R 1  are assembled against outward faces of vertical legs  27  of the bottom angles BA 1 - 3 . Preferably, at the corners of the cab  10 , where left and right side pans L 1  and R 1  and back pans B 1 , B 6  intersect, the back pans B 1 , B 6  have bolts  31  assembled and factory welded in respective slots  26  to facilitate their assembly with the side panels R 1 , L 1 .  
         [0025]    The square holes  16  in the angles BA 1 - 3  (as well as in top angles TA 1 - 3  to be discussed) and slots  26  in the pan ends and flanges  21 ,  22 , are all dimensioned to receive a common size of bolt  31 . More particularly, these accircular holes  16 ,  26  are dimensioned to receive the square shank section of a carriage bolt, step bolt or other like bolt such as a countersunk square bolt or an elevator bolt. The bolts  31  in the preferred embodiment are ⅜-16×¾″ long carriage bolts. The holes  16  can be {fraction (7/16)}″ square and the oblong slots can be {fraction (7/16)}″ wide by ¾″ long. These {fraction (7/16)}″ dimensions of the holes  16 ,  26 , enable them to receive and rotationally interlock with a square  32  (e.g. FIG. 7) on a shank under the head of the carriage bolt  31 . Similarly, nuts  33  used with the bolts  31  are a common size, e.g. ⅜″-16 hex nuts. Note also that nominal ⅜″ flat washers and ⅜″ lock washers  34 ,  35  are also used in assembling the pans and angles  
         [0026]    The common bolt, nut and washer size used to join the pans B, R, L, T and angles BA, TA, contributes to the simplicity and ease of assembly of the cab  10  since an installer need only carry a single supply of bolts, nuts and washers and a single wrench. The rotational interlock of the carriage bolts  31  and the holes  16 ,  26  advantageously avoids the need for a second wrench to hold the bolt  31  against rotation.  
         [0027]    By starting the assembly of side pans R 1 , B 1  at a corner of the car, these two intersecting pans stabilize each other to enable them to remain vertical. It will be understood from FIG. 4, that the bolts  31  and nuts  33  at the bottom edges of the pans and the nuts on the vertical edges of the side panel R 1  can be assembled by the installer while he remains on the platform  11  since the width of the pans is less than an arms reach of a typical adult workman. The bolts  31  at the bottom or platform angle BA are assembled through the angle BA 1 - 3  first and then the pan B, R and L so that the round head, designated  37  is on the inside of the completed cab and a flat washer  34 , lock washer  35  and nut  33  are on the outside of the cab. Arrows  38 ,  39  and  40  show the progression of assembly of the side pans B, R and L. For example, pan B 2  is bolted to pan B 1  and pan B 3  is bolted to pan B 2  and so forth. The installer can easily reach the slotted holes  26  along the abutting vertical flanges or legs  21  of the previous and new pans being assembled while standing or otherwise being supported on the platform  11  to assemble the bolts  31 , washers  34 ,  35  and nuts  33  and to tighten the same. The pan B 6 , like pan B 1 , ideally has its bolts  31  welded in place at the factory to facilitate attachment of pan L 1  thereto.  
         [0028]    After all of the side pans B, R, L are secured to the platform bottom angles BA and to each other, as shown in FIGS. 5 and 6 upper steel angles TA are assembled on the upper ends of the pans. Like the bottom angles BA, the top angles TA are factory formed with {fraction (7/16)} square holes  16  on both of their legs  42 ,  43  at appropriate centers to align with the slots  26  in the ends of the side pans as well as the slots  26  in the ends of the top pans. As shown most clearly in FIG. 6, the angles TA are assembled with a vertical leg  42  on the inside of the pans B, R, L and a horizontal leg  43  extending over the ends of the side pans. The bottom angles BA and top angles TA can be fabricated, for example, out of 2″×2″×{fraction (3/16)}″ structural steel angle. The top angles TA are fixed to respective side pans B, R, L with carriage bolts  31  assembled through the holes  16  in the angle legs  42  and then through the holes  26  in the pans. This procedure, again, can be accomplished by an installer supported in the space on the platform  11  to be enclosed by the cab  10 . The top angles TA serve to align the upper ends of their associated side pans, B, R, L along straight lines so as to assure a quality fit and finish. Once the top angles TA are bolted to the pans B, R, L, the top pans T can be successively bolted in place starting with T 1 . The orientation of the top angles TA with their horizontal legs  43  extending outward from the interior of the cab  10  enables a single workman or installer, working either in the cab space or on top of the top of the previously installed top panels T to easily assemble bolts through the holes  16  in the horizontal legs  43  of the top angles TA. Adjacent top pans T are secured together with bolts  31 , washers  34 ,  35 , and nuts  33 , the bolts being received and rotationally locked in aligned accircular holes or slots  26  in their abutting flanges  22 .  
         [0029]    The top pans T are typically assembled starting at the back or rear and working towards the front. The top pans T have a deeper cross-section than the side pans B, R, L by virtue of having wider flanges or legs  22  (for example, 4-½″ as compared to 1-¾″) and, are correspondingly stronger so as to support a workman on the top of the cab. The deep section of the top pans T enables recessed light fixtures  46  such as standard fluorescent fixtures to be received within the space bounded by the web, designated  47 , legs or flanges  22  and returns  24  of a top panel as shown in FIG. 8. The fixture  46  is shielded from above against a workman inadvertently stepping on the fixture or other potential damage by a stiff steel panel  48 . The panel  48  is retained in place and supported on the returns or lips  24  of the associated pan T 2  or T 4  by sheet metal screws  49 . A metal grill  51 , of expanded sheet steel, for example, is removably attached to a rectangular steel angle frame  52  bounding an aperture cut in the pan T 2  or T 4  for reception of the light fixture  46 .  
         [0030]    An emergency exit cutout is formed in the front-most top panel T 5 . The exit is closed by a door panel  56  that swings upwardly about hinges  57  welded or otherwise fixed to the web of the pan T 5  as shown in FIG. 9. A slide bolt  58  releasable locks the door  56  in a closed position. A safety switch control arrangement signals the condition where the exit door panel  56  is open. The arrangement includes a switch base  58  fastened to the respective top panel T 5 . Switch contacts in the base  58  are closed, i.e. there is electrical continuity, when a plate-like contact key  59  is received in the base. The contact key  59  is insertable and removable from the switch base by vertical motion. The contact key  59  is connected to a portion of the door panel  56  that is remote from the hinges  57  by a flexible strand  61  in the form of a link chain. In order for the door panel  56  to be opened, the contact key  59  must be removed from the switch base  58  thereby signaling that the door is open. The flexible strand connection between the swingable end of the door panel  56  and the contact key  59  avoids any sensitivity of the switch function of the base  58  and key  59  to misalignment or distortion of the door panel  56  yet provides a reliable function of interlocking the door to the switch function.  
         [0031]    It will be understood that the size of the cab  10  can be changed by adding or subtracting to the number of side and top pans and/or making changes in the size of the pans. In the illustrated case, the side pans B, R, L are nominally about 8 foot long. Where a double line opening cab is specified, the cab  10  can be modified principally by omitting the rear or back pans B 1 - 6  and bottom and top angles BA 2  and TA 2 .  
         [0032]    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.