Abstract:
This invention claims a steel elevator door guide, which contains a reinforcement beam, an attachment beam, a guide carrier and a glide. The attachment beam connects at the bottom end of a elevator cab or corridor door. The invention is held securely clamped together by fasteners, welding or glue. To further protect against any lateral movement imposed onto an elevator door, one or more frictional surfaces is engraved at contact points between individual components and safety rail(s) are provided. A noise reducing, nylon glide is attached to the guide carrier using the same fasteners as those supporting the reinforcement beam. These components are intended to prevent lateral motion of an elevator cab or corridor door even if a severe lateral pressure on the elevator doors has caused the glide to severely flex or fail.

Description:
PRIORITY 
     This application claims the priority of U.S. Ser. No. 60/927,346 filed on May 3, 2007, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to slide type elevator doors, and more particularly to guide assemblies for such doors. 
     BACKGROUND OF THE INVENTION 
     The present invention describes a new and improved elevator door guide, which guides the doors of an elevator cab, or the corridor doors that open at each floor served by the elevator, along a groove found in the sill of the door opening. 
     An elevator system is comprised of a vertical shaft and an elevator cab that moves up and down the shaft as it transports people and things between floors. An elevator contains door (s) for the elevator cab and door (s) located at each floor served by the elevator known as corridor doors. The method of installing both cab and corridor doors is similar. Generally, door sills are provided at the respective door opening on which struts are mounted. These struts support “headers”. In turn, the headers support the door hanger tracks/rails on which the entrance door panels are hung, thus bearing the bulk of the weight of the door (s). The bottom of the door (s) is then guided by the use of door guides which ride in the groove of the door sill, with the elevator door guide secured to the door at the bottom. 
     An elevator door guide does not usually come in contact with bottom of the groove in the door sill, but uses the sides of the groove to keep the door moving longitudinally along the groove, as the doors open and close. 
     Although lateral movement of the door is required for the removability of the doors for maintenance, it creates an undesirable risk of the door suddenly swinging inwardly during its normal elevator operation due to lateral forces imposed onto the door, thus causing a serious risk of injury or death when a person falls into the elevator shaft. Accidents have been known to happen where the elevator door guide disintegrates, or otherwise fail due to loads imposed on them from people leaning on doors, running into doors or even from wheel chairs hitting doors. Since the guide is hidden from view and is not needed to keep a door hanging in its place, an onlooker is unaware that the guide may be missing or has been compromised and may lean on the elevator doors. Without a guide, the door will swing into the elevator shaft, causing a person who leaned on them to fall to his or her detriment or death. A compromised guide could lead to the same result. 
     Although elevator door guides are well known, nothing in the prior art addresses this safety risk adequately. Prior inventions deal with innovative ways of how an elevator door can be guided longitudinally within a groove, but fail to provide any back-up components or strength members to ensure that the door would not swing freely into the elevator shaft if the guide is compromised. 
     For example, U.S. Pat. No. 5,174,675 (1992) to Martin discloses a guide that has only several screws keeping it in place. The guide is not made of metal and thus can fail under strong lateral pressure. The safety tabs designed to keep the door from swinging inwardly do not achieve the desired protection. First, these tabs are above the edge of the groove and assume that the guide will disintegrate, causing the door to sink into the groove. This may happen in case of a fire, which is the main focus of &#39;675 patent. However, in most cases the guide failed due to the lateral pressure exerted on the doors, for example by those leaning or running into the doors. A failure of this kind may keep the guide in place, but will make it cracked or bent. This creates a situation where the safety tabs have not yet engaged the groove, when the guide is already decisively compromised. 
     Similarly, a U.S. Pat. No. 5,706,913 to Rivera (1998) discloses another type of guide. This one is a narrow metal sliver that guides the doors along a groove located within the outer edge of the door sill. Nothing is reinforcing this sliver of a guide against a potential failure. 
     On the other hand, the present invention adds improved safety features which are highly desirable and much needed in the industry. 
     SUMMARY OF THE INVENTION 
     The invention is an elevator door guide having an attachment beam, suitable for attaching the elevator guide to an elevator door, the attachment beam having a top surface and a bottom surface, a reinforcing beam attached to the top surface of the attachment beam, and a guide carrier attached to the bottom surface of the attachment beam, wherein the guide carrier can be movably located within an elevator door track. 
     It is an objective of this invention to provide a new and useful improvement on an elevator door guide. The improved door guide is stronger and safer than door guides present in the prior art. The guide in this invention contains all metal components in locations that are most likely to experience lateral, inward pressure. The non-metal glide components are intended to be used during elevator&#39;s normal operation, whereas the metal components help withstand significant lateral pressure on the doors and keep them from swinging inward into an elevator shaft. 
     Another objective of this invention is to provide a more robust elevator guide by using a combination of fasteners, female connectors, pins and serrations to keep an elevator guide firmly and securely clamped together. 
     Yet another objective of the invention is to provide a smooth and quiet operation of the elevator doors, by employing noise reducing materials for the glide component of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the invention, showing an L-shaped beam with fasteners firmly clamping the reinforcing beam and the guide to the horizontal piece of the L-shaped beam. 
         FIG. 2  is an exploded perspective view of the various components of the invention. 
         FIG. 3  is a front, lengthwise view of the preferred embodiment showing the front surface of the vertical piece, the heads of the fasteners, and the transparent view of the guide. 
         FIG. 4  is a side view of the invention displaying the L-shaped beam connected to a door of an elevator, with the guide part of the invention ensconced within a groove of a door sill. 
         FIG. 5  is a top view of a preferred embodiment of the invention. 
         FIG. 6  is a bottom view of a preferred embodiment of the invention, showing an L-shaped beam, the glide and the safety rail (s). 
         FIG. 7  is a perspective view of the preferred embodiment of the invention showing the door guide&#39;s assembly, its attachment to an elevator door, and its position within the groove of the elevator door sill. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will now be described with reference to  FIG. 1-7  of the drawings. Identical elements in the various figures are identified with the same reference numerals. 
     Referring to  FIG. 1 , the present invention is directed to improvements of an elevator door guide.  FIGS. 1A and 1B  illustrate a fully assembled perspective view of the invention. The invention has an attachment beam  10 , a guide carrier  190 , and a reinforcement beam  120 . The attachment beam  10  allows the invention to be attached to the elevator door, and is preferably L-shaped as shown in the figures. However, attachment beam  10  can also be U-shaped, J-shaped, or I-shaped, or a flat planar shape, or any other shape suitable for attaching guide carrier  190 . In the preferred embodiment, attachment beam  10  is L-shaped and has vertical piece  20  and horizontal piece  60 . The attachment beam  10  is made preferably out of a heavy metal, such as steel, but can also be made of lighter alloys, such as aluminum or other materials such as plastic, including a variety of ferrous and non-ferrous materials, such as carbon fiber, cast iron, stainless steel, fiberglass, etc. 
     The vertical piece  20  of the attachment beam  10  (numbered in  FIG. 2 ) is mounted to elevator cab doors or the corridor doors of an elevator (not shown), with fasteners  320 . Attachment beam  10  may also be attached to the door via welding or gluing, instead of fasteners  320 . The vertical piece can either be attached to the outer surface of an elevator door, where it will be visible to the one ridding the elevator, but is preferably mounted invisibly between the outer surfaces of said door. The horizontal piece  60  resides above the sill  340  of an elevator door opening ( FIGS. 4 ,  7 ). 
     Still referring to  FIG. 1 , a reinforcing beam  120  may also be placed on the top surface  70  of the horizontal piece  60  to add additional reinforcement. Fasteners  320  are shown in an inserted position, running through the reinforcing beam  120 , the positioning slots  110  of the attachment beam  10 , and terminating in the guide carrier  190 . In the preferred embodiment, the reinforcement beam  120  is made of steel, but may also be made of a lighter metal alloy, such as aluminum or other materials such as plastic, including a variety of ferrous and non-ferrous materials, such as carbon fiber, cast iron, stainless steel, fiberglass, etc. The reinforcement beam  120  is preferably attached to the attachment beam  10  and the guide carrier  190  with fasteners  320  and at least one positioning pin  170 . 
     On the horizontal piece  60  of the attachment beam  10 , the fasteners  320  are inserted through the positioning slots  110 . The positioning slots  110 , run across the width of the horizontal piece  60  and are used to adjust the position of the guide carrier  190  with respect to the groove  330  of the door sill  340  ( FIGS. 4 &amp; 7 ). The glide  270  is preferably made out of nylon and mounted between the safety rails  230  ( FIGS. 1 &amp; 2 ). The safety rail  230  can be placed between multiple sections of the glide  270 . In another embodiment, safety rail  230  extends the full length of the guide carrier  190  wherein a separate glide  270  would be absent. Safety rail  230  could also be coated or covered with a replaceable or non-replaceable nylon cover or other coating that would reduce friction and noise. The safety rail  230  and the glide  270  can be positioned in multiple configurations with respect to each other. Thus, the guide carrier  190  could have any number or combinations of safety rails  230  and glides  270 , preferably alternating, and of the same or differing lengths. 
       FIG. 2  is an exploded, perspective diagram of individual components of the reinforced elevator door guide. Shown is the attachment beam  10 , comprised of a vertical piece  20  and a horizontal piece  60 . The vertical piece  20  contains a front surface  30 , a back surface  40 , and mounting holes  50 . The mounting holes  50  are used for fasteners  320 . The mounting holes  50  and fasteners  320  can be replaced by welding or gluing the invention to an elevator door. 
     Still referring to  FIG. 2 , horizontal piece  60  is further comprised of a top surface  70 , a bottom surface  80 , and preferably, a frictional surface  90 . Horizontal piece  60  also preferably has a plurality of positioning slots  110 , and preferably at least one positioning pin  170 . The attachment beam  10  may consist of just the horizontal piece  60 , which would then be attached or glued to the bottom of an elevator door. The frictional surface  90  may be disposed onto the top surface  70  or the bottom surface  80 . However, the preference is for the frictional surface  90  to be present on the bottom surface  80 . 
     The frictional surface  90  is preferably serrated. These serrations are evenly spaced grooves running lengthwise for the entire length of the horizontal piece  60 . The serrations are present in a trough like pattern ensuring a positive interlocking surface. While serrations are preferred, as used herein, the term “frictional surface” can also mean a knurled pattern, sanded or sand blasted surface, ridges, etc. It could also be a rubber gasket, epoxy glue or other median. The purpose of the frictional surface  90  is to decrease the chance that the individual components of the elevator guide will slip lateral or become loose when force is applied to a door. 
     Still referring to  FIG. 2 , the positioning slots  110  run perpendicular to the length of the horizontal piece  60 . Their main purpose is to allow an installer to adjust the location of the guide carrier  190 , with respect to the door sill groove  330  ( FIGS. 4 ,  7 ) by moving the carrier guide  190  laterally, perpendicular to the direction of the door sill groove  330 . It is preferred that the opposite edges of the positioning slots  110  run in a straight line. 
     To further decrease the chance that the individual components of the elevator door guide will slip laterally or become loose when forced is applied to a door, the preferred embodiment calls for at least one positioning hole  160  for a positioning pin  170 . The positing holes  160  can be drilled through once the reinforcing beam  120  and the guide carrier  190  are securely attached to the top and bottom surface respectively, of the horizontal piece  60 . 
     The reinforcing beam  120  in  FIG. 2 , is comprised of a top surface  130 , a bottom surface  140 , a plurality of mounting holes  180  for fasteners  320 , and preferably at least one positioning hole  160  for a positioning pin  170 . Additionally, the bottom surface  140  may contain a frictional surface similar to the frictional surface  90  located on the horizontal piece  60 . The mounting holes  180  correspond to the positioning slots  110  of the horizontal piece  60  and are used to for inserting fasteners  320  to bind individual elevator door guide components together. The positioning pins  170  can be used to further prevent lateral movement of guide carrier  190  and reinforcing beam  120  relative to attachment beam  10 , when force is applied to the elevator door. A series of elongated washers can be used instead of a reinforcing beam  120 . While preferred, the reinforcing beam  120  can be eliminated altogether. In this case, fasteners would be inserted directly into the positioning slots  110  of the horizontal piece  60 . For in another embodiment, top flange  200  of the guide carrier  190  is wide, thus enhancing the clamping force by spreading it over a wider area. 
     Still referring to  FIG. 2  the guide carrier  190  is preferably comprised of a top flange  200 , a top surface  210 , a bottom surface  220 , at least one safety rail  230 , a horizontal beam  240 , a plurality of mounting holes  250 , at least one positioning hole  260 , and a glide  270 . The guide carrier  190  can also be a solid beam, preferably comprised of a top flange  200 . The guide carrier  190  is diagramed having a T-shape, but can be bar shaped or L shaped (if the top flange  200  overhangs on one side only) or any other shape. The guide carrier  190  is made out of steel or lighter alloys, such as aluminum or other materials such as plastic, including a variety of ferrous and non-ferrous materials, such as carbon fiber, cast iron, stainless steel, fiberglass, etc. The main function of the guide carrier  190  is to serve as shatter resistant reinforcement member of the elevator door guide, i.e. to prevent lateral motion by an elevator door when force is applied to it. Thus, materials must be strong enough to fulfill this function. The guide carrier  190  is intended to slide along the door sill grove  330  ( FIGS. 4 ,  7 ) without making contact. 
     The top flange  200  of the guide carrier  190  is positioned horizontally with respect to the bottom surface  80  of the horizontal piece  60 , and may contain a frictional surface similar to the frictional surface  90  described for horizontal piece  60 . The top flange  200  contains a plurality of mounting holes  250  (for fasteners  320 ) that align with the positioning slots  110  of the horizontal piece  60 , and are therefore also align with the mounting holes  180  of the reinforcing beam  120 . The top flange  200  may also contain at least one positioning pin hole  260  for a positioning pin  170 . The positioning pins  170  may be added to the top flange  200  once an elevator door guide assembly is complete, by drilling a hole through the reinforcing beam  120 , attachment beam  10 , and into the guide carrier  190 . A positioning pin  170  may be placed in the hole. Alternatively the hole may be tapped, and a screw inserted therein. 
       FIG. 2  also illustrates the glide  270 , which contains a glide sidewall  275 , a glide top  280 , a glide groove  290 , a plurality of glide mounting holes  300 , and a plurality of female connectors  310 . The glide  270  is preferably made out of nylon, but can also be made out of polypropylene, plastics, rubber, leather or wood. Ball bearings could also be used. The glide grove  290  connects to the horizontal beam  240  of the safety rail  230 , while the glide top  280  may rest against the bottom surface  220  of the guide carrier  190 . The sidewall  275  may be flush with the overhang of the top flange  200 , or it can be wider or narrower than the top flange  200 . The glide mounting holes  300  are within the glide groove  290  and are intended to receive the fasteners  320  as it is inserted from the reinforcement beam  120  through the attachment beam  10  down through the guide carrier  190  towards the glide  270 . The female connectors  310  are recessed at the bottom of the glide  270 , at the terminal end of the glide mounting holes  300  and serve as the terminating point for the fasteners  320 . The fasteners  320  can instead be inserted from the bottom of the glide  270 , using the glide holes  300 , and up through the guide carrier  190 , into the attachment beam  10 , and be terminated with female connectors  310  that reside either on the top surface  70  of the attachment beam  10 , or on top surface  130  of the reinforcement beam  120 . 
     The glide  270 , and the safety rail(s)  230  of the guide carrier  190  reside within the door sill groove  330  ( FIGS. 4 ,  7 ) and guide elevator cab or corridor doors longitudinally back and forth along the door sill grove  330 . Alternatively, the safety rail (s) can be located in the center with the glide located to either or both sides of the safety rail (s). Yet another alternative is to eliminate the glide  270  completely and to use one solid safety rail  230  instead. The glide  270  is wider than the safety rail  230  and is intended to slide against the sides of the door sill grove  330  ( FIG. 4 ,  7 ) as the doors open and close. The glide  270  is yet another member of this invention that serves to prevent lateral movement by an elevator door, which is an undesirable safety risk. 
       FIG. 3  shows the elevator door guide from the front view. Shown are the vertical piece  20 , a front surface  30 , a back surface  40 , a plurality of mounting holes  50  for fasteners  320 , and at least one positioning pin  170 . Also shown in  FIG. 3  is a drawing of the guide carrier  190  along its length. The fasteners  320  are inserted into the mounting holes  50  from the back surface  40  toward the front surface  30 . This drawing illustrates that the glide  270  is located between the guide safety rail (s)  230  and contains recessed areas for the female connectors  310 . As shown, the fasteners  320  are inserted into the reinforcement beam  120  and run through the entire elevator door guide assembly, to terminate within the safety rails  230  and within the female connectors  310 . Mounting pins  170  serve as back-up connectors to the fasteners  320 , in case the latter get loose during elevator&#39;s continuous operation. Welding can serve as an alternative to positioning pins  170 . 
       FIG. 4  describes the elevator door guide with respect to the door sill grove  330 . Illustrated are a side view of the attachment beam  10 , a reinforcement beam  120 , a safety rail  230 , a glide  270 , a door sill groove  330  and a door sill  340 . The safety rail  230  is visible in the foreground, while the glide  270  is visible in the background, behind the safety rail  230 . The glide  270  is wider than the safety rails  230  to minimize undesirable noise which would be emitted if the metallic safety rails  230  were to slide against the metallic door sill groove  330 . The glide  270  also prevents wearing out of the door sill groove. Yet, since the rigid safety rails  230  are still present within the door sill groove  330  rather than the weaker, more flexible glide  270  being present alone within the said groove  330 , prevention of lateral movement by an elevator door is not diminished. Thus, safety is not compromised. 
       FIGS. 5 and 6  are the top and bottom views, respectively, of the horizontal piece  60  of the attachment beam  10 . 
     Finally  FIG. 7  illustrates how an elevator door guide is mounted to a cab or corridor door and how it provides longitudinal motion along the door sill groove sill  330 . Note that this is a transparent, perspective drawing. In reality the entire assembly or at least the horizontal piece is beneath the elevator door and is not visible to an elevator user. 
     This invention provides vast safety improvements over prior art by providing improved clamping strength between the parts of the elevator door guide and by decreasing the likelihood of lateral motion due to the failure of the glide. All components are attached to each other in a way that promotes clamping strength and prevents lateral slippage, perpendicular to the motion of the door along the groove in the door sill. Another example of improved reliability and safety is that the mounting fasteners  320  of the attachment beam  10  are parallel to the lateral force that may be exerted on an elevator door. The lateral force is sometimes created when a person or an object leans, presses or hits against the doors while either waiting for en elevator in the corridor or riding inside the elevator cab. Greater resistance to lateral motion is achieved by having some of the fastening be parallel to the lateral force, such as by fasteners  320  located on the vertical piece  20 , while other fastening is perpendicular to the lateral force, such as when the longitudinal motion is induced by the presence of the guide carrier  190  and the door sill groove  330 . 
     Presence of the reinforcement beam  120  improves support for the fasteners  320  of the guide since it contacts all sides of the fastener equally. Without it, the fasteners  320  would be inserted directly into the positioning slots  110  of the horizontal piece  60 . The positioning slots  110  offer only two sides to support the fasteners, with the other sides being open to permit adjustment of the door relative to the groove  330  in the sill  340 . 
     Additional safety is provided by the horizontal beam  240  that is mounted within the glide groove  290 . This configuration reinforces the lateral strength of the glide by having the exterior walls  275  of the glide  270  prevent a lateral slippage in connection between the horizontal beam and the glide  270 . 
     Yet another safety feature is added by having metallic safety rails  230  extend into the groove of the sill  330  alongside the glide. If the glide  270  experiences increased lateral force, it may give way and flex in the same direction as the pressure, permitting the door to move inwardly into the elevator shaft. This motion will continue until the safety rails  230  come in contact with the side of the door sill grove  330 , preventing a possible glide failure and keeping the doors from swinging laterally into the elevator shaft. 
     One of the more innovative and essential safety enhancements of this invention is the addition of the frictional surface  90  located in places where metal surfaces of the reinforcing beam  120 , the horizontal piece  60  and the top flange  200  come in contact with each other. The presence of the frictional surface  90  decreases the likelihood of slippage under pressure and interlocks the parts to prevent movement. Ideally, the frictional surface can be engraved onto the bottom surface  140  of the reinforcement beam  120 , the top and bottom surfaces of the vertical piece  60 , and the top surface  210  on the top flange  200  of the guide carrier  190 , or in all three at the same time. The top flange of the guide carrier  190  need not have a distinct appearance from the rest of the guide, but may instead be incorporated into the shape of the guide. For example, if the guide is a solid beam, the top flange can represent the edge of the beam facing the attachment beam and having mounting holes for fasteners, but need not have a shape different from the rest of the beam. 
     Increasing the contact area between the metal components with frictional surfaces  90  may decrease the need for some of the components. Meaning, there may not be a need to have a separate reinforcement beam  120 . In such a case the top surface  210  of the top flange  200  and the bottom surface  80  of the horizontal piece  60  will need to contain serrations engraved over the entire contact area. Serrations need not be grooves however. Any substantially rough but even surface will have a similar, slippage resistant effect. 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made only by way of illustration and that numerous changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.