Abstract:
A ceiling assembly for an elevator cab that includes, among other features, an improved emergency access panel. The access panel appears to be part of a monolithic ceiling panel. When unlocked, the access panel is permitted to drop along a series of slides and remains substantially horizontal. Tracks are provided in the frame of the ceiling assembly that permits the dropped access panel to easily slide away to give access to the interior of the elevator cab through the ceiling. Drops in each of the tracks help bias the access panel open when it is placed in a fully open position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to elevators, and more particularly, to ceilings and emergency access hatches in passenger elevator cabs. 
     2. Description of the Related Art 
     Several designs for elevator cab ceiling have been designed in the past. None of them, however, includes a modular system with an easy, smooth operating and safe emergency fireman&#39;s escape panel integrated into the ceiling. 
     Applicant believes that the closest prior art reference is found in the ceilings of many elevator cabs operating across the world. However, the prior art differs from the present invention because the means to access the interior of the cab from the roof in an emergency is bulky and often difficult to move. Further, the prior art ceiling access panels must be tilted at such an angle during their normal use in an emergency so as to prohibit many types of lighting fixtures or wasting interior cabin height with ceiling mechanicals. 
     Other patents describing the closest subject matter and other known design that have been in use for years, provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these teachings suggest the novel features of the present invention. 
     SUMMARY OF THE INVENTION 
     It is one of the main objects of the present invention to provide a safe elevator including an effective and easy to operate emergency ceiling panel integrated into the design. 
     It is another object of this invention to provide an elevator ceiling that uses a minimal volume of space to allow for maximum volume and ceiling height in an elevator cab. 
     It is still another object of the present invention to provide an elevator ceiling system that is readily adaptable and adjustable to retrofit a wide variety of elevator cabs. 
     It is yet another object of this invention to provide such a system and device that is inexpensive to manufacture and maintain while retaining its effectiveness. 
     Another object of the present invention is to provide a light weight ceiling so that is easier on the installer and easier on the user to open close and maintain. 
     Another object of the invention is to improve the ease of engaging and disengaging the locking mechanism so that external access is enhanced. 
     Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which: 
         FIG. 1  represents a top side perspective view of a version of an elevator ceiling rolling moving section. 
         FIG. 2  shows a top side perspective view of a variety of a substantially complete ceiling assembly. 
         FIG. 3  illustrates a perspective view of an example of a first slide in an extended mode. 
         FIG. 4  is a perspective view representation of an example of a second slide in a retracted mode. 
         FIG. 5  represents a side elevation view of a version of a track assembly. 
         FIG. 6  demonstrates a side elevation view of an iteration of a track assembly. 
         FIG. 7  shows a side elevation view of another variant of a track assembly. 
         FIG. 8  is a perspective view of a top side of an embodiment of a ceiling assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Elevators are often refurbished and remodeled during their service life to refresh and update their look. These replacement ceilings as well as original ceilings in new elevator cabs are generally required to include an emergency access panel. In American elevators the emergency access panel or door is operable primarily from above and outside of the cab to be convenient to first responders and fire department rescue personnel allowing access to trapped passengers. 
     Often the emergency access panel (sometimes also referred to as a door, panel, access or hatch) in prior art designs is infrequently used and is difficult to operate. Historical designs use articulating arms that essentially allow a portion of the ceiling of the elevator cab to fall down and swing or roll out of the way. 
     The inelegant prior art emergency access panels took up a significant amount of space in the ceiling of the cab which is at a premium in the defined constraints of the elevator cab. 
     An improvement was needed to increase the available interior space of the elevator cab. The present design and the variations thereto succeed at this goal as well as allowing for smoother movement that further results in a safer and mechanically superior access panel that can be retrofit into existing cabs equally as well as it can be incorporated into original, new equipment. 
     Referring now to the drawings, where the present invention is shown in several versions throughout the drawings and is generally referred to with numeral  10  in  FIG. 1 , where it can be observed that it basically includes, among other features, a drop panel  11 , a rail assembly  12 , a track  14 , a drop  15 , a track  16 , a drop  17 , a rail assembly  18 , a track  19 , a track  20 , a slide  21 , a slide  22 , a slide  23 , a slide  24 , a panel  25 , a panel  26 , a panel  27 , a brace  28 , a brace  29 , a light  30 , a light  31 , a light  32 , a wheel  33 , an axle  34 , a slot  35 , a sleeve  36 , a flange  37 , a bracket  38 , a wheel  39 , an axle  40 , a slot  41 , a sleeve  42 , a flange  43 , a bracket  44 , a slot  45 , a frame  46 , a frame  47 , a fixed panel  48 , a light  49  and a lock  50 . 
     Generally, an emergency drop panel  11  is shown in  FIG. 1  with the rail assembly  12  and rail assembly  18 . The drop panel  11  is shown assembled with other elements of a ceiling assembly in more detail in  FIG. 2 . 
     In this version of the device the drop panel  11  is comprised of panel  25 , panel  26  and panel  27  connected side by side with the brace  28  along one edge and the brace  29  along the other edge. In this fashion the drop panel  11  is essentially a rigid and singular structure, meaning that these parts remain fixed relative to each other during normal operation of the elevator and ceiling. 
     Light  30  is optionally provided in panel  25 , light  31  is optionally provided in panel  26  and light  32  is optionally present in panel  27 . To ensure that the drop panel  11  has sufficient clearance under the fixed panel  48  during opening of the drop panel  11 , the light  30 , light  31  and light  32  should be low profile. In other words, the height of the light  30 , light  31  and light  32  should not extend above the respective panel  25 , panel  26  and panel  27  so that they would contact the underside of the fixed panel  48  when the drop panel  11  is lowered and slid underneath the fixed panel  48  when opening the ceiling. 
     Panel  25 , panel  26  and panel  27  may be affixed to the brace  28  and brace  29  during initial fabrication remote from the site of the elevator cab into which it will be installed. Alternatively, for some applications it may be preferred that the manufacturer supply the panels  25 - 27  and braces  28  and  29  separate so that they can be fit on site by the installer to accommodate differing as-built conditions and ensure a tight, square fit with balanced reveals between the panels  25 - 27  and around the adjoining wall panels. 
     At each of the four corners of the drop panel  11  is a slide mechanism. As shown in  FIG. 1 , slide  22  and slide  21  are along the outside edge of panel  25 . On the opposite side of the drop panel  11  is panel  27  that includes slide  23  and slide  24 . 
     In at least one aesthetically pleasing and regulation compliant design, the drop panel  11  is approximately the same dimension, or a little smaller than, the fixed panel  48 . This can vary widely depending on the application, size of the elevator cab and local regulations that dictate the dimensions of the fireman&#39;s access as generally defined by the size of the drop panel  11 . 
     In a version of the design, flexibility of this system for use in addition to a doghouse or storage compartment is present while still allowing full functionality of an emergency ceiling panel. Some cabs have a doghouse attached to them that are used for moving crews to carry in long objects, like rolls of carpet, etc. The doghouse is generally not to be used from inside the cab to get out of the cab. The doghouse can also be used to maintain the lights or other mechanicals of the elevator. 
     Generally, the size of the drop panel  11  should be sufficient to allow the safe extraction of trapped elevator passengers in the case of an emergency. The first responder or fireman&#39;s requirements, including nature of the equipment they carry in a rescue situation should also be considered by the designer of the ceiling system that is fit into any elevator cab system. 
     It should be appreciated that the drop panel  11  can be located adjacent to or relative to the canopy exit or the drop ceiling exit. Any version of the system can be retrofit into any canopy without having to limit the exit. Of course, a custom designed new elevator can be easily adapted to employ the present device. 
     As seen in  FIG. 2 , the perimeter structure of the ceiling panel is formed by the frame  46  and frame  47  along the front and back of the ceiling panel along with the rail assembly  18  and rail assembly  12  on the left and right. Onto these frame members the fixed panel  48  is affixed. The drop panel  11  is moveable relative to the fixed panel  48 , frame  47 , frame  46 , rail assembly  18  and rail assembly  12 . 
     Generally, the drop panel  11  is moveably connected to the rail assembly  18  and rail assembly  12 . In normal operation of the elevator onto which this ceiling assembly is attached, the drop panel  11  is locked against the frame  46  so that the drop panel  11  is substantially coplanar to the fixed panel  48 . In this way in normal use of the elevator cab the riders do not see evidence that the drop panel  11  is moveable relative to the balance of the ceiling structure. 
     The fixed panel  48  is shown in the version of the device demonstrated in  FIG. 2  to have three lights  49 . One is called out but three are shown. These lights  49  are optional but are preferred by most owners of elevator cabs. Design considerations to limit the distance that the lights  49  below the fixed panel should be observed. Because the drop panel  11  will slide under the fixed panel during operation in an emergency the lights  49  should not be permitted to obstruct movement in the path of the drop panel  11 . 
       FIG. 3  and  FIG. 4  show an example of a slide  23  and slide  24 , respectively. As applied to the configuration of the version of the device shown in  FIGS. 1 and 2 , the slide  23  is materially similar in design to the slide  21  and the slide  24  is materially similar in design to the slide  22  as seen in  FIG. 1 . 
     The primary difference between the slide  23  (and by reference slide  21 ) and slide  24  (and by reference slide  22 ) is that slide  23  is configured for the lower track  14  on the rail assembly  12  where slide  24  is configured for the upper track  16  on the rail assembly  12 . To maintain a generally horizontal drop panel  11  during while in an open mode and a closed mode the wheel  33  in slide  23  is offset from the wheel  39  in slide  23  a distance roughly equal to the difference between the track  20  and the track  19  as seen in  FIGS. 5 and 6 . 
     The wheel  33  is affixed to the sleeve  36  at the axle  34 . The axle  34  permits rotational movement of the wheel  33  when the wheel  33  is moved in the track  19  so that the slide  23  assembly can fluidly move along the length of the track  19 . The flange  37  is affixed to the edge of the drop panel  11 . 
     The wheel  39  is affixed to the sleeve  42  at the axle  40 . The axle  40  permits rotational movement of the wheel  39  when the wheel  39  is moved in the track  20  so that the slide  24  assembly can fluidly move along the length of the track  20 . 
     Slide  23  and slide  24 , similarly to the corresponding slides on the opposite edge of the drop panel  11 , extend and retract longitudinally along the slot  35  and slot  41 . The sleeve  36  is dimensioned to fit over the bracket  38  and keep in line during the longitudinal movement. The sleeve  36  slides along the bracket  38 . The slot  35  in the bracket  38  is provided to limit the range of travel of the sleeve  36  relative to the bracket  38 . Generally, the length of the slot  35  is similar to the overall longitudinal range of travel of the slide  23   
     The sleeve  42  is likewise dimensioned to fit over the bracket  44  and keep in line during the longitudinal movement. The sleeve  42  slides along the bracket  44 . The slot  41  in the bracket  44  is provided to limit the range of travel of the sleeve  42  relative to the bracket  44 . Generally, the length of the slot  41  is similar to the overall longitudinal range of travel of the slide  24 . A tab  51  is optionally provided on the inside surface of the sleeve  42  and rides within the slot  41  to provide a positive limit of the upper and lower range of travel of the bracket  44 . A similar tab may be included in any of the several slide designs. 
     Looking at  FIGS. 5 ,  6  and  7 , three sequential positions of the drop panel  11  are shown.  FIG. 5  demonstrates the normal operating position of the ceiling assembly with the drop panel  11  affixed in the rail assembly  18  so that the drop panel  11  is substantially coplanar with the fixed panel  48 . Wheel  39  rides in track  20  and wheel  33  rides in track  19 . It is in this position that the lock  50  is engaged in the slots  45  (seen in  FIG. 8 ) to lock and prevent movement of the drop panel  11  relative to the rail assembly  18  and fixed panel  48 . While in this normal operating mode the ceiling appears to be a single unified panel to any occupants of the elevator cab. 
     When the drop panel  11  is to be opened, for example in an emergency to extricate trapped passengers from the elevator cab, the lock  50  is disengaged from the slots  45 . After disengaging, the drop panel  11  must be unhinged by pulling up and pushing out the drop panel  11 . This allows the drop panel  11  to drop when all four slides can extend simultaneously. The dropped, but not yet open, panel  11  is shown in an intermediate mode in  FIG. 6 . Generally, the slides  23  and  24  extend sufficiently to allow the drop panel  11  and light  32  to clear underneath the fixed panel and integral light  49  when the drop panel  11  is in an open mode. 
       FIG. 7  shows the drop down panel  11  in an open mode where the interior of the elevator can be accessed from on top of the elevator cab and occupants can exit. The wheel  39  of the slide  24  falls by gravity into the drop  52  at the same time the wheel  33  of the slide  23  falls by gravity into the drop  53 . 
     The drops  52  and  53  are essentially dips in the end of the tracks  20  and  19 , respectively, which provide a means to bias the drop panel  11  in the open position when the drop panel  11  is fully opened. The drops  52  and  53  are spaced on the rail assembly  18  at substantially the same distance apart as the slides  23  and  24  so that both slides encounter the drop at the same time when the drop panel  11  is fully opened. Drops  15  and  17  are similar in form and function to drops  52  and  53 . 
     In a version of the slide  23  or  24 , the brackets  38  and  44  move relative to the sleeves  36  and  42  with the aid of a series of intervening ball bearings. This can provide for a smooth and precise movement of the slide assemblies. Alternatively, a low friction material can provide a smooth and durable wear surface to improve the performance of the slide assemblies&#39; retraction and extension movements. 
       FIG. 8  shows a version of the ceiling from a top side where the several assemblies and sub-assemblies are shown to also include a lock  50  that is slideably attached to the top side of the drop panel  11 . There are slots  45  on the frame  46  that correspond to tabs on the lock  50 . The lock  50  can be manipulated from the top of the cab to engage or disengage the tabs from the slots  45  to free the drop panel  11  form the frame  46  so that the drop panel  11  can be opened or locked close. 
     In at least one version of the ceiling device the lock  50  is accessible from the interior of the elevator cab so that maintenance can be performed. When the lock  50  is accessible from the interior of the cab it is preferable to hide or disguise it in such a way as to deter improper opening of the drop panel  11 . 
     A version of the elevator ceiling can be fairly described as being an elevator ceiling attached to an upper side of an elevator cab comprised of a drop panel, a fixed panel and a frame assembly. The frame assembly defines a perimeter of an elevator ceiling. The frame assembly includes a first rail assembly along a first segment of the perimeter that is substantially parallel to a second rail assembly along a second segment of the perimeter. The fixed panel is affixed at a first edge to the first rail assembly and at a second edge to the second rail assembly. The first rail assembly includes a first track along the length of the first rail assembly. The second rail assembly includes a second track along the length of the second assembly. The first track and second track are substantially the same length. The drop panel has a first end of a first slide on a first edge and a first end of a second slide on a second edge. A second end of the first slide is engaged in the first track and a second end of the second slide is engaged in the second track. When in a closed mode the drop panel is adjacent to and coplanar to the fixed panel. When in the closed mode a lock connects the drop panel to the frame assembly such that the drop panel and fixed panel are substantially coplanar. When the lock disengages the drop panel from the frame assembly the first slide and second slide are allowed to extend vertically thereby lowering the drop panel a predetermined distance into a lowered mode. When in a lowered mode the second end of the first slide moves in the first track and the second end of the second slide moves in the second track thereby transitioning the drop panel into an open mode. When the drop panel is fully in the open mode the first slide and second slide are biased to hold the drop panel in the open mode. 
     Some versions of the elevator ceiling can further include the first rail assembly having a third track parallel to the first track and the second rail assembly includes a fourth track parallel to the second track. A third slider connects the third track to an edge of the drop panel. A fourth slider connects the fourth track to an edge of the drop panel. It can also optionally have an end of the first track that has a drop that the second end of the first slide falls into to bias the drop panel in an open mode. Another option can be that both the first slider and the second slider extend to an equal predetermined distance that maintains the drop pane substantially horizontally when the drop panel is in an open mode. Another option can be that in the closed mode the elevator ceiling has a surface area substantially similar to a surface area of an upper side of an elevator cab. 
     The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.