Abstract:
A rooftop unit for a machine-roomless elevator ( 28 ) includes a selectively removable cover ( 38 ) that covers the machine components ( 46 ). In one example, the removable cover is movable relative to the rooftop without requiring removal of the entire cover.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention generally relates to machine-roomless elevator systems. More particularly, this invention relates to a rooftop mounted unit that houses the components used to operate the elevator system as desired.  
         [0002]     Elevator systems typically include a cab that moves within a hoistway. Most systems include a counterweight that is associated with the cab. Roping typically couples the cab to the counterweight. A drive motor rotates a drive sheave to move the roping to cause the desired movement of the elevator cab within the hoistway.  
         [0003]     Traditionally, elevator systems have required a machine room for housing the drive motor, the drive sheave and other operation control components. Such components typically are referred to collectively as the “machine,” which is the basis for the “machine room” designation. Machine rooms often were located on top of buildings. The use of machine rooms, while effective, is not without drawbacks. A building construction must be specifically arranged to fit or support the machine room and the components within it. In some instances, special architectural considerations are needed to adequately support the machine room at the rooftop level.  
         [0004]     Machine rooms introduce additional material cost and other construction issues for designers and during building construction.  
         [0005]     More recently, it has been proposed to eliminate machine rooms and to otherwise house the drive and control components of an elevator system. A variety of approaches in this regard have been proposed. This invention provides a unique, compact and cost effective solution where it is desirable to eliminate an elevator system machine room.  
       SUMMARY OF THE INVENTION  
       [0006]     In general terms, this invention is a rooftop unit that houses the machine components of an elevator system under a removable cover that can be opened or removed for maintenance or component replacement as needed. The rooftop unit sits atop a roof surface of a building without requiring special construction to accommodate the rooftop unit.  
         [0007]     One example assembly designed according to this invention includes a support base that is adapted to be secured to the roof surface. The support base supports at least some of the elevator system machine components. The support base has an opening through which selected portions of the elevator system extend, such as the roping, to achieve desired elevator system operation. A cover is removably secured to the support base to cover the machine components supported on the base.  
         [0008]     One example cover designed according to this invention includes at least one access panel extending through the cover. A portion of the cover is selectively moveable relative to a remainder of the cover to open or close the access opening. In one example, up to one-half of the cover can be manually moved to provide access to the machine components.  
         [0009]     The cover and support base preferably provide a watertight seal that prevents natural elements from entering the space beneath the cover for protecting the machine components and preventing the natural elements from entering the hoistway through the opening in the support base.  
         [0010]     In one example, the cover is completely removable. The cover preferably is infrequently completely removed but that option is available with this invention.  
         [0011]     The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  schematically illustrates an elevator system of an example embodiment designed according to this invention.  
         [0013]      FIG. 2  is a partial exploded schematic illustration of an example assembly designed according to an embodiment of this invention.  
         [0014]      FIG. 3  schematically shows another example cover. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     An elevator system  20  is schematically illustrated in  FIG. 1 . The system  20  includes an elevator cab  22  that is selectively moveable within a hoistway  24  to carry loads between different levels or landings  26  of a building  28 . Only selected portions of the cab supporting structure within the hoistway  24  are schematically illustrated and although only one landing  26  is shown, those skilled in the art appreciate that an elevator system typically provides access to multiple levels or landings within a building.  
         [0016]     The building  28  includes a roof surface  30 . The illustrated example includes a hoistway top portion  32  that extends slightly above the majority of the roof surface. There may be situations where this invention is applicable that the hoistway top portion  32  is no higher than the roof surface  30 .  
         [0017]     A rooftop unit  34  is secured to the hoistway top portion  32 . The illustrated example rooftop unit  34  includes a support base  36  and a cover  38 . The support base  36  preferably is permanent secured to the rooftop  30  or the hoistway top portion  32 . In one example, the base  36  comprises a set of at least two horizontally positioned beams above the hoistway. The rooftop  30  and the hoistway top portion  32  are generically referred to in this document as a “roof surface.” 
         [0018]     The cover  38  preferably is not permanently secured to the rooftop or the support base  36 . Instead, the cover  38  preferably is removable from the support base to provide access to components supported by the support base  36 . In one example, a crane or other similar machine is required to remove the entire cover  38 . In another example, only a portion of the cover is removable.  
         [0019]     The cover  38  preferably is received to establish a closed interface  39  between the cover and the support base  36 . An example securing arrangement includes fasteners such as bolts securing the cover to the base. In one example, no separate sealing elements or materials are required at the interface  39 .  
         [0020]     In another example, the roof surface includes a curb portion formed as part of the roof surface. The curb portion operates as the edges of the support base  36  for receiving the cover  38  in a manner that protects the machine components from the natural elements.  
         [0021]     The illustrated example of  FIG. 1  includes an access opening  40  through one side of the cover  38 . The illustrated example includes a hinged support  42  that allows a portion of the cover  38  to be selectively moved to provide access to the interior of the unit  34  through the access opening  40 . Although one access opening is shown in  FIG. 1 , a plurality of such openings and a variety of items for selectively covering such openings are within the scope of this invention.  
         [0022]     As best appreciated from  FIG. 2 , the support base  36  preferably supports a machine assembly  44  that provides the motive force for moving the elevator cab  22  as desired within the hoistway  24 . The machine assembly  44  preferably is very compact compared to traditional machine assemblies that required an entire machine room to house the motor and other components. The illustrated example includes a motor controller  46  that controls operation of a motor  48 , which preferably is an electric motor. A drive sheave  50  rotates responsive to movement of the motor  48  to cause movement of a plurality of belts (i.e., roping)  52  over the drive sheave  50  so that the cab  22  moves as desired. A plurality of belt terminations  54  preferably are supported within the rooftop unit  34 .  
         [0023]     Additionally, a temperature control device  56 , such as a fan or a heater, may advantageously be supported in the rooftop unit  34 .  
         [0024]     The support base  36  and cover  38  together form a housing for completely housing the machine assembly  44  components that are supported above the roof surface of the building. An opening (not visible in the illustrations) through the support base  36  allows the roping  52  to extend down into the hoistway so that appropriate elevator system operation occurs.  
         [0025]     In one example, the total height of the rooftop unit  34  above the roof surface of the hoistway top  32  is less than one meter. In one example, the top of the cover  38  is only approximately 77 cm (2 feet 7 inches) above the top surface of the hoistway top  32 . The overall dimensions of the assembly  34  are significantly reduced compared to machine rooms that were traditionally supported above roof surfaces.  
         [0026]     A variety of materials may be used to make the cover, support base or both. Examples include stainless steel, aluminum, fiberglass, and plastic. The chosen material must withstand the anticipated environmental conditions of that building location. Those who have the benefit of this description will realize what materials will meet the particular needs of a specific situation and will be able to select the material best suited for their situation.  
         [0027]     As best seen in  FIG. 3 , the support base  36  in the illustrated examples includes a generally planar base surface  60 . A plurality of side portions  62  extend upward (relative to the rooftop) away from the planar surface  60 . The height of the side portion  62  preferably is chosen based upon the typical rainfall in the region where the building is located. Snowfall, when expected, also must be accommodated to ensure adequate machine component protection. Local building codes may dictate requirements for the side portion  62  height. In one example, the height is 200 mm.  
         [0028]     The cover  38  includes a top portion  64  and a plurality of sidewalls  66  extending away from the top portion. In the illustrated example, the sidewalls  66  of the cover  38  are received within the space defined by the side portion  62  of the support base  36 . An appropriate fit at the interface between the sidewalls  66  and the side portions  62  ensures that natural elements (i.e., rain or snow) do not enter the space protected by the cover  38  so that the machine components supported by the support base  36  remain isolated from the environment as desired.  
         [0029]     The example of  FIG. 3  includes a hinged connection  70  between portions of the cover  38 . In this example, the forward side (according to the drawing) can be manually lifted about the hinged connection to provide access beyond that available through the openings  40 .  
         [0030]     A significant advantage of this invention is the space savings provided by the unique and compact arrangement of components. Another significant advantage is having a selectively removable cover  38  that allows for an individual to readily access the components within the rooftop unit  34  for installation, maintenance or replacement as may be needed.  
         [0031]     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.