Abstract:
The present invention provides an elevator cab comprising at least one wall formed from two or more panels, each panel having a front surface forming an interior surface of the elevator cab, a female connector and a male connector attached to opposing edges of the front surface, respectively. The male connector includes a projection which is parallel to but transversely displaced from the front surface and the female connector defines a slot which is parallel to, but transversely and laterally displaced from, the front surface. The slot has an opening facing towards the front surface. The projection of one wall panel is laterally inserted through the opening and into the slot of a neighbouring panel and a securing element is transversely inserted between the two wall panels.

Description:
[0001]     The present invention relates to elevators and, in particular, to an elevator cab and a construction method thereof.  
       BACKGROUND OF THE INVENTION  
       [0002]     Conventional elevator cabs or cars generally comprise neighbouring panels that are connected together using conventional fasteners such as nuts and bolts to form the side walls. To ensure that the fasteners are not visible from within the finished elevator cab, the fasteners are normally located on the outside of the cab. Such a system is described and shown in DE-C1-4446023. Accordingly, a large amount of the assembly has to be carried out in the relatively small space between the cab and the hoistway wall which can be frustrating, difficult and time consuming.  
         [0003]     A solution to this problem is disclosed in U.S. Pat. No. 6,082,501 whereby a first panel is initially secured by a floor bracket to the cab platform so that the panel is aligned along a side edge of the platform. The panel has a hook portion which extends in towards the cab. A second panel having a J-shaped latch member extending out towards the hoistway is then maneuvered into position such that the J-shaped latch member can be inserted into the hook portion of the first panel. In this position the second panel extends at an angle greater than 75° to the side edge of the platform and therefore the majority of the second panel projects from the platform into the hoistway. Accordingly, the clearance between the platform and the hoistway walls must be sufficient to accommodate the second panel in this position. Once the latch member has been inserted into the hook portion, the second panel is rotated into the desired position on the platform and secured by a floor bracket to the platform.  
         [0004]     The continual pressure on the elevator industry to maximize space efficiency has resulted in that the designer can no longer afford the clearance between the platform and the hoistway walls required to accommodate the second panel in a 75°, pre-rotation position.  
         [0005]     An alternative solution is discussed in U.S. Pat. No. 5,842,545 wherein the side walls comprise a plurality of wall panels each having at least one longitudinal edge interlocking with a longitudinal edge of an adjacent wall panel to connect the wall panels together without any additional fasteners. Each interlocking longitudinal edge has a C- or G-shaped cross sectional flange with cutaway areas defining a plurality of alternating locking members and slots. The. locking members of a wall panel flange are insertable through slots of an adjacent wall panel flange and longitudinally moveable relative thereto to engage the locking members of the two wall panel flanges to connect the wall panels together. Accordingly, during assembly a wall panel must be lifted vertically so that its locking members are horizontally aligned to the slots in the adjacent wall panel. Then it is moved horizontally to insert the locking members through the slots in the adjacent wall panel. Finally, it must be lowered so that the locking members engage with the locking members of the adjacent wall panel.  
         [0006]     Although this solution certainly avoids the major problem associated with U.S. Pat. No. 6,082,501 in that the assembly of the cab can be confined substantially within the area of the platform, it requires a large amount of manual dexterity and strength on the part of the technician. From the dimensions quoted in U.S. Pat. No. 5,842,545, each of wall panels could weight up to 90 kg, making it extremely difficult for the technician to manually raise each wall panel, hold it in the elevated position so as to align it with the neighbouring panel and insert it through the slots of the neighbouring panel, and finally to lower it so that it engages with the neighbouring panel and rests on the platform.  
         [0007]     A further problem associated with the prior art elevator cabs discussed above is that during construction each wall panel must be effectively locked or secured in position (either to the platform in U.S. Pat. No. 6,082,501, or to a neighbouring panel in U.S. Pat. No. 5,842,545) before subsequent panels may be added in the same manner to form an entire side wall of the cab. Any misalignment of the panels in these construction methods has a cumulative effect and there is no tolerance in these systems to make any final adjustments after the wall has been constructed to rectify the misalignments.  
         [0008]     Accordingly the objective of the present invention is to provide a panel assembly, an elevator cab assembly and a construction method thereof wherein the assembly of the cab is confined substantially within the area of the platform and can be realized without lifting one panel relative to a neighbouring wall panel.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0009]     This objective is achieved by providing an elevator cab comprising at least one wall formed from two or more panels, each panel having a front surface forming an interior surface of the elevator cab, a female connector and a male connector attached to opposing edges of the front surface respectively, wherein the female connector defines a slot which is parallel to but transversely and laterally displaced from the front surface, and the male connector includes a projection which is parallel to but transversely displaced from the front surface. The slot has an opening facing towards the rear of the front surface, the projection of one panel is inserted through the opening and into the slot of a neighbouring panel and a securing element is inserted between the neighbouring panels.  
         [0010]     Accordingly, the projection of one panel is sandwiched within the slot from the neighbouring panel, preventing relative transverse movement therebetween. The subsequent insertion from the front of the securing element between the neighbouring wall panels securely seats the projection within the slot and thereby prevents relative lateral movement therebetween. Hence, the neighbouring walls panels are effectively locked together.  
         [0011]     The panels can be interconnected from the front and therefore installed from the elevator cab platform. The wall panels are interconnect primarily through lateral displacement rather than transverse displacement, therefore the clearance between the platform and the hoistway walls can be reduced to the minimum.  
         [0012]     Preferably, the front surface may comprise two perpendicular surfaces which meet at a corner. A panel having this configuration can be used as a corner panel to interconnect panels from mutually perpendicular walls.  
         [0013]     Preferably, the neighbouring panels forming the walls are initially interconnected through engagement of the male and female connectors as previously described to prevent relative transverse movement. When the entire cab wall has been thus formed, final adjustments can be made to the individual panels before the securing elements are inserted between the panels to securely lock the panels together. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The present invention is hereinafter described by way of specific examples with reference to the accompanying drawings in which:  
         [0015]      FIG. 1  is cross-section of a wall panel according to the present invention;  
         [0016]      FIGS. 2A  to  2 D illustrate the sequence in which the wall panel of  FIG. 1  is attached to an identical neighbouring wall panel to construct a portion of a wall of an elevator cab;  
         [0017]      FIG. 3  illustrates a corner panel interconnecting two wall panels according to  FIG. 1  which form a portion of two mutually perpendicular elevator cab walls;  
         [0018]      FIG. 4  is a section of an insert according an embodiment of the invention; and  
         [0019]      FIG. 5  is an exploded perspective view of an elevator cab incorporating wall formed from the wall panels of FIGS.  1  to  3 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]      FIG. 1  shows a cross-section of a wall panel  2  according to the present invention. The wall panel  2  is connected to identical wall panels  2  to form a side wall of an elevator cab  1  (as shown in  FIG. 5 ). Each wall panel  2  comprises a front planar surface  4  which eventually forms a part of the interior surface of the elevator cab  1 . A female connector  20  is provided at a first longitudinal edge  6  of the front surface  4 . Similarly, a male connector  10  is provided at a second longitudinal edge  8  of the front surface  4 .  
         [0021]     The female connector  20  comprises a first leg portion  18  attached at one end to the first longitudinal edge  6  of the front surface  4  and projecting perpendicularly backwards therefrom, and attached at the other end to a J-shaped profile extending parallel to but recessed from the front surface  4 . The J-shaped profile has a first member  22  and a web member  24  interconnecting the first member  22  with a second member  26 . The second member  26  is disposed parallel to and in front of the first member  22 . Furthermore, the second member  26  is shorter than the first member  22 . Accordingly, a slot  28  is defined by the first member  22 , the web member  24  and the second member  26  of the female connector  20 . The slot  28  has an opening  30  that faces towards the first leg portion  18 . Preferably, the free end of the second member  26  has a lip  32 .  
         [0022]     The male connector  10  comprises a second leg portion  12  attached at one end to a second longitudinal edge  8  of the front surface  4  and projecting perpendicularly backwards therefrom, and attached at the other end to a projection  14  extending parallel to and behind the front surface  4 .  
         [0023]      FIGS. 2A  to  2 D show the sequence in which two identical wall panels  2 ,  2 ′ are secured together to construct a portion of wall of the elevator cab  1 . Although both panels  2 ,  2 ′ are identical, for the purpose of clarity, a prime (′) has been used in the reference numerals to distinguish features of the left panel  2 ′, referred to hereinafter as the second or neighbouring panel, from those of the right panel  2  referred to hereinafter as the first panel. Furthermore, only the male connector  10 ′ side of the second panel  2 ′ and only the female connector  20  side of the first panel  2  are shown in the Figures.  
         [0024]     As shown in  FIG. 2A , the first panel  2  is moved laterally in the direction A towards the second panel  2 ′. During this relative movement, the female connector  20  passes behind the male connector  10 ′ of the neighbouring panel  2 ′. After the second member  26  and lip  32  of the female connector  20  have cleared past the projection  14 ′ of the male connector  10 ′, the panels  2 ,  2 ′ can be brought transversely together as depicted by the arrow B in  FIG. 2B  so that the first member  22  of the female connector  20  is in abutment with the projection  14 ′ of the male connector  10 ′ of the neighbouring panel  2 ′. The panels  2 ,  2 ′ are then laterally separated from each other as depicted by the arrow C in  FIG. 2C . During this relative movement, the lip  32  helps to guide the projection  14 ′ through the opening  30  and into the slot  28  of the female connector  20 . In this position, the projection  14 ′ is securely sandwiched between the first member  22  and the second member  26  of the female connector  20 , thereby preventing relative transverse movement between the panels  2 ,  2 ′.  
         [0025]     A generally U-shaped longitudinal insert  40  is provided, having opposing sides  42  which spread backwards and outwards from an intermediate connecting portion  44 . As shown in  FIG. 2D , the insert  40  is pushed in a transverse direction D into the cavity  50  defined at one side by the first leg portion  18  of the female connector  20 , at the rear by the first member  22  of the female connector  20 , and at the other side by the second leg portion  12 ′ of the male connector  10 ′. During this motion, the opposing sides  46  are elastically deformed to provide reactional forces against the first leg portion  18  of the first panel  2  and the second leg portion  12 ′ of the second panel  2 ′. These reactional forces bias the two panels  2 ,  2 ′ away from each other, which consequently ensures that the projection  14 ′ of the male connector  10 ′ is securely seated against the web portion  24  of the female connector  20  and that relative lateral movement between the panels  2 , 2 ′ is prevented.  
         [0026]     Accordingly, the sandwiching of the projection  14 ′ of the male connector  10 ′ between the first and second members of the female connector  20  prevents relative transverse movement between the panels  2 , 2 ′ and the reactional forces exerted by the insert  40  on the panels  2 ,  2 ′ prevents relative lateral between the panels  2 , 2 ′. Therefore, all horizontal relative movement of the panels  4 &#39; 4 ′ is essentially prohibited and the two panels  2 ,  2 ′ are effectively locked together.  
         [0027]     Two or more panels  2  are fixed together in this manner to form a wall of the elevator cab  1 .  
         [0028]      FIG. 3  shows a cross-section of a corner panel  102  interconnecting two wall panels  2 ,  2 ′ which form a portion of two mutually perpendicular elevator cab walls. The corner panel  102  is essentially identical to the wall panel  2  of  FIG. 2  except it comprises two perpendicular front surfaces  104   a  and  104   b  which meet at a corner  105 . A female connector  120  is attached to and projects perpendicularly backwards and outwards from a first longitudinal edge  106  on the first front surface  104   a . A male connector  110  is mounted to and projects perpendicularly backwards from a second longitudinal edge  108  on the second front surface  104   b.    
         [0029]     The method of locking the panels together is exactly the same as previously described and is shown diagrammatically in  FIG. 3  by the arrows A to D. In a first step A, the female connector of one of the panels is moved laterally behind the male connector of the neighbouring panel. In step B, the neighbouring panels are brought transversely together as so that the first member of the female connector is in abutment with the male connector of the neighbouring panel. Then in step C the panels are laterally separated from each other. Finally, in step D the insert  40  is transversely inserted between the first leg portion of one panel and the second leg portion of the neighbouring panel.  
         [0030]     In the above description, the term lateral means aligned to the plane defined by the associated cab wall and the term transverse means perpendicular to the plane defined by the associated cab wall.  
         [0031]      FIG. 4  illustrates in greater detail an insert  40  according one embodiment of the invention. Projections  46  are provided on the opposing sides  42  to engage with corresponding holes  48  provided in the first leg portion  18  and second leg portion  10  of the panels  2 .  
         [0032]      FIG. 5  is an exploded perspective view showing an elevator cab  1  according to the present invention. On the installation site, a platform  3  is the first component of the cab  1  which is brought into the elevator hoistway. The platform  3 , which acts as the floor of the cab  1 , is generally the main load-bearing component of the cab  1  and is normally supported on a car frame for movement within the elevator hoistway. In the present embodiment, the platform  3  is manufactured from a single sheet of metal which has its edges turned down through an angle of 90° to form side walls  5 . A plurality of brackets  7  are stamped from the side walls  5  to create U-shaped channels along the periphery of the platform  3 .  
         [0033]     The cab walls are then constructed by inserting the wall panels  2 ,  2 ′ into the U-shaped channels on the platform  3 . Preferably the neighbouring panels  2 ,  2 ′ forming the walls are initially interconnected through engagement of the male and female connectors as previously described to prevent relative transverse movement. When the entire cab wall has been thus formed, final adjustments can be made to the individual panels  2 ,  2 ′ before the inserts  40  are pushed into the cavities  50  to securely lock the panels together.  
         [0034]     Next a drop ceiling  13  can be brought into the cab  1  and lowered onto the panels  2 ,  2 ′. The drop ceiling  13  is essentially an inverted version of the platform  3 . In the present embodiment, the ceiling  13  is manufactured from a single sheet of metal which has its edges turned up through an angle of  900  to form side walls  15 . A plurality of brackets  17  are stamped from the side walls  5  to create inverted U-shaped channels along the periphery of the ceiling  3  to receive the panels  2 ,  2 ′.