Patent Publication Number: US-10773927-B2

Title: Elevator trip hazard light system and method

Description:
The present invention relates to a method of adapting an elevator system and to an elevator system that has been adapted according to the invention. 
     Lift cars used in elevator systems to convey passengers between floors of a building are designed to stop to within ±2 millimetres of a destination floor landing. This is to limit the size of the step that exists between the lift car floor and the landing. However, precise stopping of a lift car is not always achieved and this can present a trip hazard for passengers entering and exiting the lift car. 
     It is known to illuminate the gap between the landing and the lift car by directing light at the gap from above. However, such methods of illumination do not adequately highlight the step between the lift car floor and the landing, and therefore do not properly indicate the presence of a trip hazard. 
     It is an object of the invention to provide an elevator system and a method of adapting an elevator system to specifically indicate the existence of a trip hazard between the lift car floor and the landing. 
     According to the present invention, there is provided a method of adapting an elevator system to warn elevator users of the existence of a vertical misalignment between a floor of a lift car and a landing surface adjacent to which said lift car stops, and where there is a gap between facing parallel walls depending vertically downwards from a leading edge of the lift car floor and a leading edge of the landing surface, respectively, the method including positioning a luminaire on at least one of said walls so that the luminaire directs light toward the opposing wall irrespective of said vertical misalignment, and so that at least a portion of the light from said luminaire reflects off said opposing wall prior to passing out of said gap. 
     Where the elevator system has a maximum accepted level of misalignment at which the elevator system will remain operational, the method may comprise positioning the luminaire at a distance below said edge by a distance which is greater than said maximum accepted level of misalignment. 
     The method may further comprise making the or each wall reflective. 
     The method may further comprise applying a reflective material or coating to the or each wall. 
     The method may further comprise applying a reflective sheet to the or each wall. 
     Where the wall depending from the leading edge of the lift car floor is a toe guard, the method may include the step of positioning a luminaire on said toe guard. 
     Where the toe guard comprises an opening, the method may include the step of positioning a luminaire in the opening so that it is flush with, or recessed below, a front surface of the toe guard. 
     Where the toe guard comprises a plurality of openings provided across the width of the toe guard, the method may include the step of mounting a luminaire in each of the plurality of openings to provide illumination across the width of the toe guard. 
     Where the luminaire is an LED strip light, the method may include the step of mounting the LED strip light to the or each wall. 
     Where the toe guard comprises a mounting surface extending from a front face of the toe guard, the method may include the step of mounting a luminaire onto the mounting surface to direct light across the front face of the toe guard. 
     Where said mounting surface is perpendicular to a front face of the toe guard, the method may include the step of mounting a luminaire onto the mounting surface to direct light across the front face of the toe guard. 
     The method may comprise the additional steps of applying a translucent filter to the luminaire and directing light from said luminaire through the translucent filter to flood said gap with diffuse light. 
     Where the wall depending from the leading edge of the lift car floor is a translucent toe guard, the method may include the step of positioning the luminaire to direct light into the toe guard such that the toe guard diffuses the light emitted by the luminaire to flood said gap with diffuse light. 
     According to the present invention there is also provided an elevator system comprising a lift car, the system being adapted to warn elevator users of the existence of a vertical misalignment between a floor of the lift car and a landing surface adjacent to which the lift car stops, and where there is a gap between facing parallel walls depending vertically downwards from a leading edge of the lift car floor and a leading edge of the landing surface, respectively, the system including a luminaire on at least one of said walls, wherein the luminaire is configured to direct light toward the opposing wall irrespective of said vertical misalignment so that at least a portion of the light from said luminaire reflects off said opposing wall prior to passing out of said gap. 
     There may be a maximum accepted level of misalignment between the lift car floor and the landing at which the elevator system will remain operational, the luminaire being positioned at a distance below said edge by a distance which is greater than said maximum accepted level of misalignment. The maximum accepted level of misalignment may be a level at which, if exceeded, the elevator will no longer function and may become disabled. 
     One or both walls may be reflective. 
     A reflective material or coating may be applied to one or both walls. 
     A reflective sheet may be applied to one or both walls. 
     The wall depending from the leading edge of the lift car floor may be a toe guard. 
     The toe guard may comprise an opening, the luminaire being received in the opening so that a light emitting portion of the luminaire is flush with, or recessed below, a front face of the toe guard. 
     The toe guard may comprise a plurality of openings extending across the width of the toe guard, wherein a luminaire is received in each of the openings to provide illumination across the width of the toe guard. 
     The luminaire may be an LED strip light. 
     The toe guard may comprise a mounting surface extending from a front face of the toe guard, and wherein the luminaire is mounted on the mounting surface to direct light across the front face of the toe guard. 
     The mounting surface may be perpendicular to the front face of the toe guard so that the luminaire directs light transversely across its front face. 
     The luminaire may comprise a translucent filter configured to diffuse light emitted by the luminaire to flood said gap with diffuse light. 
     The wall depending from the leading edge of the lift car floor may be a translucent toe guard, wherein the luminaire is configured to direct light into said toe guard such that said toe guard diffuses the light emitted by the luminaire to flood said gap with diffuse light. 
    
    
     
       So that the present invention may be more fully understood embodiments thereof will now be described with reference to the accompanying drawings in which: 
         FIG. 1  is a section view of a lift shaft having a lift car; 
         FIG. 2  is a partial section view of a lift shaft having a lift car according to the present invention; 
         FIG. 3  is a partial section view of the lift shaft of  FIG. 2 , wherein the lift car is in a first position; 
         FIG. 4  is a partial section view of the lift shaft of  FIG. 2 , wherein the lift car is in a second position; 
         FIG. 5  is a partial detail view of a toe guard according to an embodiment of the present invention; 
         FIG. 6  is a partial detail view of a toe guard according to another embodiment of the present invention; 
         FIG. 7A  is a partial detail view of a toe guard according to another embodiment of the present invention; 
         FIG. 7B  is a partial detail view of a toe guard according to another embodiment of the present invention; 
         FIG. 8A  is a partial section view of a lift shaft having a lift car according to another embodiment of the present invention; 
         FIG. 8B  is a partial section view of the lift shaft of  FIG. 8A , wherein the lift car is in a second position; 
         FIG. 9A  is a partial detail view of a toe guard according to another embodiment of the present invention; 
         FIG. 9B  is a partial detail view of a toe guard according to another embodiment of the present invention; 
         FIG. 9C  is a partial detail view of a toe guard according to another embodiment of the present invention. 
     
    
    
     A conventional elevator system  1  as shown in  FIG. 1  is described herein for reference. The elevator system comprises a lift car  2  suspended in a vertical lift shaft  3  and moveable along the lift shaft  3  to convey passengers in the lift car  2  between any number of building floor levels. The building floor level immediately around the lift shaft is referred to as the landing  4 . Landing doorways  5  are formed in the lift shaft  3  to communicate with each landing  4 . Landing doors  6  are provided to selectively block the landing doorway  5  and are slideably arranged with respect to the landing doorway  5  so that they may take a closed position to block the landing doorway  5 , when the lift car  2  is not aligned with the landing doorway  5 , and an open position, when the lift car  2  is aligned with the landing doorway  5 , so that waiting passengers standing on the landing  4  can enter and exit the lift car  2 . With the landing door  6  in the closed position, waiting passengers standing on the landing  4  are protected from exposure to the open lift shaft  3 . 
     The lift car  2  comprises a floor  7  and a plurality of vertical walls  8  arranged around the floor  7  to enclose the floor  7  and to define a safe area in which passengers stand when aboard the lift car  2 . The lift car  2  yet further comprises a roof  9  which connects the top edges of the vertical walls  8  and protects the passengers from exposure to any moving parts used to move the lift car  2  along the lift shaft  3 . A lift car doorway  10  is provided in at least one of the vertical walls  8  and is disposed so as to align with the landing doorway  5  when the lift car  2  is stationary at the respective landing  4 . Lifts car doors  11  are slideably arranged with respect to the lift car doorway  10  to selectively block the doorway  10 . When the lift car doorway  10  is aligned with a landing doorway  5 , the lift car door  11  and the landing door  6  simultaneously slide into an open position to allow passengers to enter and exit the lift car  2 . The lower edges of the landing and lift car doorways  5 / 10  are respectively referred to as the landing sill  13  and lift car sill  12 . 
     In operation of the elevator system  1 , the lift car  2  is moved along the lift shaft  3  until the lift car doorway  10  and the landing doorway  5  of a required floor are aligned. The lift car door  11  and the landing door  6  simultaneously slide into an open position to allow passengers to enter and exit the lift car  2 . A motion sensor or similar detecting system determines that the movement of passengers is complete and the lift car door  11  and the landing door  6  slide into a closed position. The lift car  2  is then moved along the vertical shaft  3  to convey the passengers to another floor whereupon the doorways align and the respective doors slide into an open position to allow the passengers to disembark onto the landing  4  and any waiting passengers to enter the lift car  2 . 
     An elevator system  1  according to the present invention is shown in  FIG. 2 , wherein the lift car  2  further comprises a toe guard  14 . The toe guard  14  comprises a flat plate  15  mounted below the lift car doorway sill  12  to extend vertically below the lift car floor  7  so that a planar face  16  of the flat plate  15  is proximate to a vertical wall  17  of the lift shaft  3 . The toe guard  14  further comprises a bent section  18  that extends out of alignment from the flat plate  15  along a lower edge  19  of the flat plate  15 , the bent section  18  extending away from the vertical wall  17  of the lift shaft  3 . The toe guard  14  extends along the full width of the lift car  2 . In the event the lift car  2  stops above the level of the landing  4  and the landing doors  6  are opened, the toe guard  14  protects waiting passengers standing on the landing  4  from exposure to the lift shaft  3  through the space between the landing  4  and the lift car floor  7 . 
     The lift car  2  of  FIG. 2  is shown stopped with the lift car floor  7  and landing  4  aligned and coplanar and with both the lift car doors  11  and landing doors  6  in an open position so that passengers may easily enter and exit the lift car  2 . With the lift car floor  7  and landing  4  aligned as shown, passengers may enter and exit the lift car  2  without any risk of tripping over the sill of the lift car  12  or the sill of the landing  13 . According to the present invention, the toe guard  14  further comprises a luminaire  20  mounted to the flat plate  15  to illuminate the vertical wall  17  of the lift shaft  3 . Light from the luminaire  20  reflects off the vertical wall  17  of the lift shaft  3  to illuminate the gap between the respective landing and lift car sills  13 / 12 . The gap between the respective landing and lift car sills  13 / 12  is herein referred to as the running clearance  21 . 
     Referring to  FIG. 3 , the lift car  2  of  FIG. 2  is shown stopped with the lift car floor  7  and landing  4  misaligned so that the lift car floor  7  is disposed a distance above the landing  4  sufficient to present a trip hazard to passengers entering the lift car  2 . The elevator system determines that the lift car  2  has stopped and so opens both the lift car and landing doors  11 / 6  so that passengers may enter and exit the lift car  2 . Light from the luminaire  20  reflects from the vertical wall  17  of the lift shaft  3  to impinge upon the toe guard  14 , therefore illuminating the toe guard  14  to passengers entering the lift car  2  and warning them of the trip hazard presented by the lift car sill  12  as a result of the misalignment of the lift car floor  7  and landing  4 . 
     Referring to  FIG. 4 , the lift car  2  of  FIG. 2  is shown stopped with the lift car floor  7  and landing  4  misaligned so that the lift car floor  7  is disposed a distance below the landing  4  sufficient to present a trip hazard to passengers exiting the lift car  2 . The elevator system determines that the lift car  2  has stopped and so opens both the lift car and landing doors  11 / 6  so that passengers may enter and exit the lift car  2 . Light from the luminaire  20  reflects from the vertical wall  17  of the lift shaft  3  to illuminate the vertical wall  17  of the lift shaft  3  to passengers exiting the lift car  2  and warning them of the trip hazard created by the misalignment of the lift car floor  7  and landing  4 . 
     The luminaire  20  is mounted to the planar face  16  of the toe guard  14  a distance (d) below the lift car floor  7 . According to the invention, the distance (d) is selected such that the luminaire  20  remains below the level of the lift car floor  7  and the landing  4  when the lift car and landing doors  11 / 6  are open so that passengers are not in line of sight of the luminaire  20 ; therefore passengers looking directly at the running clearance  21  are not dazzled. 
     According to the invention the elevator system may be configured to prevent the lift car doors  11  and or the landing doors  6  from opening if the lift car floor  7  and the landing  4  exceed a maximum accepted level of misalignment. In such embodiments, the distance (d) is selected to be greater than the maximum accepted level of misalignment such that the luminaire  20  remains below the level of the lift car floor  7  and the landing  4  when the lift car and landing doors  11 / 6  are open. 
     In one embodiment of the invention, the maximum accepted level of misalignment is between 50 and 300 millimetres. In a preferred embodiment, the maximum accepted level of misalignment is 100 millimetres. The maximum accepted level of misalignment may be a level at which the lift will become disabled if any further misalignment occurs or at which an alarm will sound to warn a lift operator that a maximum acceptable level of misalignment has been exceeded and maintenance to the lift is required. 
     It shall be appreciated that the distance (d) below the lift car floor  7  that the luminaire  20  is mounted will determine the intensity of light visible to passengers. Moving the mounting point of the luminaire  20  in a direction further below the lift car floor  7  will reduce the intensity of light reflected toward a passenger. 
     According to the invention, the luminaire  20  may be permanently illuminated when the elevator system is in operation. Alternatively, the luminaire  20  may be configured to be illuminated only when required so as to save energy. In one embodiment, the luminaire is configured to be illuminated only when the lift car doors  11  are open on receipt of an electrical signal from the lift car door opening apparatus. In another embodiment, the luminaire  20  is configured to be illuminated by a motion sensor so that the luminaire  20  is switched on as a passenger approaches the running clearance  21 . In yet another embodiment, the luminaire  20  is configured to be illuminated at the same time as the lift car lighting. In certain embodiments, the luminaire  20  may only illuminate if a misalignment, or a certain level of misalignment, is detected. It will also be appreciated that the luminaire may not be illuminated continuously but may flash or strobe to enhance the visibility of the misalignment to a user. 
     The luminaire may take a number of forms and be mounted in a number of ways as described in more detail below. 
     A toe guard  14  according to an embodiment of the present invention is shown in  FIG. 5 , an opening  22  is formed in the toe guard  14  into which a luminaire  20  is mounted. This provides the advantage that the luminaire  20  can be recessed in the toe guard  14  so that a portion of the luminaire body  23  is located behind the toe guard  14 , distal to  3   o  the vertical wall  17  of the lift shaft  3 . This enables a light emitting portion  24  of the luminaire  20  to be flush with or recessed from a face  16  of the toe guard  14  proximate to the vertical wall  17  of the lift shaft  3 . Therefore, a larger luminaire  20  can be used in elevator systems where the clearance between the face of the toe guard  16  and the vertical wall  17  of the lift shaft  3  would be limiting. Furthermore, with the luminaire  20  mounted so that the light emitting portion  24  of the luminaire  20  is flush with or recessed from the face  16  of the toe guard  14 , the light emitting portion  24  of the luminaire  20  is spaced further from the vertical wall  17  of the lift shaft  3  than if mounted proud of the face  16  of the toe guard  14 . It shall be appreciated that this increases the spread of light incident on the vertical wall  17  of the lift shaft  3  and therefore increases the proportion of light, and thus the intensity of light, reflected toward a passenger. Likewise moving the light emitting portion  24  of the luminaire  20  closer to the vertical wall  17  of the lift shaft  3  reduces the proportion of light, and thus the intensity of light, reflected toward a passenger. 
     It shall be appreciated that any number of openings  22  may be provided in the toe guard  14  for any number of luminaires  20  to be mounted therein. Likewise, the distribution and positioning of the openings  22  may be selected as required, for example, in one unillustrated embodiment, a plurality of luminaires  20  are provided and are mounted in respective openings  22  arranged in a row extending transversely across the width of the toe guard  14 . 
     A toe guard  14  according to another embodiment of the invention is shown in  FIG. 6 , linear luminaires  25  such as strip LED lighting can be mounted to the face  16  of the toe guard  14 . Therefore, no further modification of the toe guard  14  is required reducing the complexity of the device and the installation time. 
     A toe guard  14  according to yet another embodiment of the invention shown in  FIGS. 7A and 7B , the toe guard  14  is modified further to provide mounting surfaces  26  perpendicular to the face  16  of the toe guard  14 . In one example of this embodiment, specifically illustrated in  FIG. 7A , the mounting surfaces  26  are formed from a portion of the toe guard adjacent vertical edges  27  of the toe guard  14 . Said portion of the toe guard  14  is delineated by pairs of cut lines  28  extending perpendicular from each vertical edge  27  and a bend line  29  extending between distal ends of each pair of cut lines  28 . To form the mounting surfaces  26 , each of said portions is bent away from the toe guard  14  along said bend lines  29  to extend perpendicular to the face  16  of the toe guard  14 . Luminaires  20  are mounted to the mounting surfaces  26  so that light shines transversely across the face  16  of the toe guard  14  toward an opposing vertical edge  27 . In another example of this embodiment shown in  FIG. 7B , L shaped brackets  30  are mounted to the face  16  of the toe guard  14 . Each L shaped bracket  30  has a base plate  31  which is attached to the toe guard  14  by any suitable means and a mounting plate  32  upstanding perpendicularly from one edge of the base plate  31  to which a luminaire  20  is mounted. The bracket  30  is oriented such that light from the luminaire  20  shines transversely across the face  16  of the toe guard  14  toward one of said vertical edges  27  of the toe guard  14 . However, it shall be appreciated that the bracket  30  may alternatively be mounted so that the luminaire  20  is oriented in any desired direction. By shining light across the face  16  of the toe guard  14  toward a distal vertical edge  27 , the intensity of light directed toward the vertical wall  17  of the lift shaft is reduced, therefore reducing the intensity of light reflected toward a passenger. 
     The elevator system may additionally comprise first and second reflectors  33 / 34  as shown in  FIG. 8A , wherein the first reflector  33  is mounted to the vertical wall  17  of the lift shaft  3  proximate to the landing sill  13  and extending along the full width of the sill  13 , and the second reflector  34  is mounted along an upper end of the toe guard  14  proximate to the lift car door sill  12 . The lift car  2  of  FIG. 8A  is shown stopped with the lift car floor  7  and the landing  4  misaligned so that the lift car floor  7  is disposed below the landing  4 . With the lift car and landing doors  11 / 6  in the open position, passengers standing in the lift car are in direct line of sight of the first reflector  33 . A portion of light emitted by the luminaire  20  is incident on the first reflector  33  and is reflected toward the passengers standing in the lift car  2 . 
     Referring now to  FIG. 8B , the lift car  2  of  FIG. 8A  is shown stopped with the lift car floor  7  and the landing  4  misaligned so that the lift car floor  7  is disposed above the landing  4 . With the lift car and landing doors  11 / 6  in the open position, passengers standing on the landing  4  are in direct line of sight of the second reflector  34 . A portion of light emitted by the luminaire  20  is reflected by the first reflector  33  so that a portion of reflected light is incident on the second reflector  34  whereupon it is reflected toward the passengers standing in the lift car  2 . The gap or running clearance  21  acts as a light guide to guide the light in an upward direction along the gap as it is reflected off the opposing walls and until it emerges from the gap and is visible to passengers. The reflectors may act to diffuse the light to reduce its intensity and/or glare. 
     In  FIGS. 8A and 8B , the respective reflectors are configured to increase the intensity of light reflected toward passengers and therefore increase the visibility of a trip hazard. Although in the above embodiments luminaires  20  are mounted to the toe guard  14 , it shall be appreciated that luminaires  20  may alternatively be mounted to the vertical wall  17  of the lift shaft  3 , wherein a luminaire  20  is disposed proximate to each landing  4 . When the lift car doorway  10  is aligned to a respective landing doorway  5 , light from the luminaire  20  floods the gap between the vertical wall  17  of the lift shaft  3  and the toe guard  14  to illuminate the running clearance  21  in the manner described above. In such embodiments, the luminaire  20  is mounted a distance below the respective landing so that the luminaire  20  remains below the level of the lift car floor  7  and the landing  4  when the lift car and landing doors  11 / 6  are open so that passengers are not in line of sight of the luminaire  20 . 
     In embodiments wherein the elevator system is configured to prevent the lift car doors n and or the landing doors  6  from opening if the lift car floor  7  and the landing  4  are not aligned within a maximum accepted level of misalignment, the luminaire  20  is mounted a distance below the respective landing  4  greater than the maximum accepted level of misalignment so that the luminaire  20  remains below the level of the lift car floor  7  and the landing  4  when the lift car and landing doors  11 / 6  are open. 
     Further embodiments of the invention are shown by  FIGS. 9A to 9C , in such embodiments the toe guard  14  is made of a translucent material with at least one luminaire  20  mounted to direct light into the translucent toe guard  14 . This has the effect of diffusing the emitted light so that it is spread out and softened. 
     In the embodiment shown by  FIG. 9A , one or more luminaires  20  are embedded into the translucent toe guard  14  adjacent the lift car sill  12  and arranged to direct light to diffuse through said toe guard  14  toward the lower edge  19  of the toe guard  14 . 
     In the embodiment shown by  FIG. 9B , luminaires  20  are mounted along the vertical edges  27  of the translucent toe guard  14  to direct light to diffuse through said toe guard  14  toward the respective opposing edge  27 . 
     In the embodiment shown by  FIG. 9C , one or more luminaires  20  are mounted to a back face  36  of the translucent toe guard  14 . The luminaires  20  are attached to a mounting frame  35  which extends away from the back face  36  in order to support the luminaires  20  at a distance from the back face  36 . By supporting the luminaires  20  at a distance from the back face  36 , the spread of light incident on the back face  36  is increased so that light diffused through the toe guard  14  is more evenly emitted from the opposing planar face  16  of the toe guard  14 . 
     It shall be appreciated that in the above embodiments, by diffusing light through a translucent toe guard  14 , a substantial portion of the planar face  16  of the toe guard  14  becomes light emitting. Therefore, when the lift car floor  7  and the landing  4  are within the maximum accepted level of misalignment, the light emitting portion of the planar face  16  of the toe guard  14  will overlap the vertical wall  17  of the lift shaft  3  so that at least a portion of the light emitted by the one or more luminaires  20  is reflected off of the vertical wall  17 . Thus, when the lift car floor  7  and the landing  4  are misaligned so that the lift car floor  7  is disposed below the landing  4 , light reflected from the vertical wall  17  of the lift shaft  3  warns passengers exiting the lift car  2  of the trip hazard created by the misalignment. Similarly, when the lift car floor  7  and landing  4  are misaligned so that the lift car floor  7  is disposed above the landing  4 , light reflected from the vertical wall  17  of the lift shaft  3  illuminates the sill  12  of the lift car  2  to warn passengers entering the lift car  2  of the trip hazard created by the misalignment. It shall be yet further appreciated that, when the lift car floor  7  is disposed above the landing  4  to the extent that the toe guard  14  is visible to passengers waiting on the landing  4 , the diffuse light emitted from the toe guard  14  is sufficiently softened by the translucence of the toe guard  14  so that passengers looking at the running clearance  21  are not dazzled. 
     It shall be appreciated that in the embodiments shown by  FIGS. 9A to 9C , the toe guard  14  may instead be transparent and the one or more luminaires  20  mounted a distance below the lift car sill  12  so that, when the lift car floor  7  and the landing  4  are within the maximum accepted level of misalignment, light is transmitted through the transparent toe guard  14  toward the vertical wall  17  of the lift shaft  3 . 
     According to the invention, the luminaire  20  may be any appropriate lighting device, though preferably the luminaire  20  is an LED lighting device such as an LED strip light or an LED spot light. Advantageously, multiple coloured LEDs may be provided. It is envisaged that multiple coloured LEDs provide the option of changing the colour of light used to illuminate the running clearance  21  according to the floor level. Further, it is envisaged that the colour of the LED light may be set according to the lift operators preferences. 
     It is envisaged that the method may be carried out on existing lift car systems to retrofit them with the luminaire according to the invention.