Refractive sheet lighting assembly for an elevator

Information

  • Patent Grant
  • 6830355
  • Patent Number
    6,830,355
  • Date Filed
    Thursday, January 9, 2003
    21 years ago
  • Date Issued
    Tuesday, December 14, 2004
    20 years ago
Abstract
An elevator cab lighting assembly comprising a refractive sheet mounted on the interior of the elevator cab. A light source is mounted at and conducts light into an outer edge of the refractive sheet. The light received at the outer edge of the travels along the refractive sheet and passes out of the planar surface and inner edge of the sheet exposed within the interior of the cab. The refractive sheet may be randomly sanded or sandblasted to provide diffuse light. The sheet may be etched or routed in standard or custom designs to provide accent highlighting. The lighting assembly is housed within a transom assembly that may be accessed from the exterior of the cab.
Description




FIELD OF THE INVENTION




The present invention relates generally to the field of elevators, and, more particularly, to the field of lighting for elevator cabs.




BACKGROUND




Lighting assemblies conventionally available for elevator cabs use overhead or ceiling-mounted lighting fixtures. There are several disadvantages associated with conventional lighting assemblies.




Conventional lighting assemblies typically require 4 to 10 inches of extra cab height to accommodate the light fixtures and the diffuser devices used to scatter the light evenly throughout the cab. The assemblies require additional structural components in the ceiling of the cab to carry the weight of the assemblies. The additional structural components add to the overall size and weight of elevator car, which can be very undesirable, especially in modernizing existing elevators. The administrative codes governing elevator modernization often place very tight restrictions on the weight of replacement elevator parts (including the cab) used in the modernization.




Conventional lighting assemblies are easily accessible to the passengers within the cab and exposed to vandalism or inadvertent damage. If broken, shards of glass or other components of the fixture may fall into the interior of the elevator cab and injure passengers. Replacing and repairing broken components on conventional lighting assemblies is often expensive and time-consuming.




SUMMARY OF THE INVENTION




The invention overcomes the problems associated with conventional lighting assemblies for elevators by providing a novel elevator cab lighting assembly that uses a refractive sheet to provide a diffuse, glare-free light within the interior of the elevator cab. The invention also comprises elevator cabs containing such lighting assemblies.




The lighting assembly of the invention comprises a refractive sheet having opposed planar surfaces, an inner edge, and an outer edge. The sheet is mounted on the cab and has a portion exposed to the interior of the elevator cab. A light source is mounted at and conducts light into the outer edge of the sheet. Light transmitted from the outer edge refracts randomly and internally along the longitude of the sheet and passes through the portion exposed to the interior of the elevator cab.




The refractive sheet can be formed from any suitable material which would provide a diffuse, glare-free light within the interior of the elevator cab. In one embodiment, the refractive sheet comprises acrylic. However, any clear or translucent material may be used. For example, the sheet may also comprise other plastics or glass. Although a preferred thickness for the refractive sheet is about 0.250 inches, the sheet can vary in thickness or material provided its structural integrity is maintained when the elevator is in operation, and it emits the desired amount of light into the cab. The portion of the sheet exposed to the interior of the cab may include the inner edge of the sheet or may also include an area along one of the planar surfaces. The sheet may be a variety of shapes, such as a rectangle, a semi-circle, a spline, or any other linear or curved shape.




One of the planar surfaces may be randomly sanded or sandblasted. One of the planar surfaces may also be etched or routed. The etching or routing may be in standard or custom designs to provide accent highlighting. The sheet may also include a mirrored layer (or a polished metal foil) or a painted layer on one of the planar surfaces. The inner edge may also contain a mirrored layer to reflect light back into the portion bounded by planar surfaces and thus enhance the intensity of light passing through the portion exposed to the interior of the elevator cab.




The sheet typically will be mounted on a ceiling surface of the cab, but it may also be mounted on other surfaces within the cab, such as a wall or floor surface.




In a preferred embodiment, the lighting assembly also includes a transom assembly for housing the outer edge and the light source. The transom assembly also contains a guide for enhancing conduction of light into the outer edge. The transom assembly may be mounted on the interior or exterior of the cab. When mounted on the exterior of the cab, the transom assembly actually defines the upper front comer section of the cab and intrudes into the space or ceiling height of the cab.




The transom assembly preferably includes a perforated face plate for being exposed to the interior of the cab and for diffusing light from the light source into the cab. The perforations of the face plate can be in the form of holes, gratings, grill bars, a plurality of slots or other light transmitting features. The face plate is of a sturdy configuration and is resistant to tampering and other forms of damage. In this case, the transom includes a lens mounted between the light source and the face plate. In addition, the inner edge is preferably aligned with the face plate and is disposed just above the top of the face plate.




The invention provides effective illumination of an elevator cab from a space saving lighting assembly. The invention is designed so as to meet the elevator code for adequate cab illumination. The code requires at least 5 foot candles power intensity at the threshold of the elevator with the doors closed.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an isometric view of an elevator cab with an externally accessible transom containing the light assembly of the invention.





FIG. 1A

is an isometric view of an elevator cab comprising a transom assembly mounted on the interior of the cab.





FIG. 2

is a side view of the elevator cab portion displaying a cross-section of the lighting assembly concept of the invention.





FIG. 2A

is a side view of an elevator cab portion displaying a cross-section of another embodiment of the invention, wherein a refractive sheet is adapted for being mounted on a wall surface of the cab.





FIG. 3A

is an oblique view of a lighting assembly according to the invention having a semi-circular refractive sheet extending from the transom assembly.





FIG. 3B

is an underside oblique view of the lighting assembly shown in FIG.


3


A.





FIG. 3C

is a side view of the lighting assembly shown in FIG.


3


A.





FIG. 4A

is an oblique view of a lighting assembly according to the invention having a refractive sheet extending to an inner edge that is aligned with the face plate of the transom assembly.





FIG. 4B

is an underside oblique view of the lighting assembly shown in FIG.


4


A.





FIG. 4C

is a side view of the lighting assembly shown in FIG.


4


A.











DETAILED DESCRIPTION OF THE INVENTION




The following embodiments are described with reference taken to the attached figures, which are intended to illustrate the invention but not limit the scope to these embodiments.





FIG. 1

generally shows an elevator cab


10


having doors


15


A and


15


B and containing the lighting assembly


11


of the invention located in a transom


12


that is mounted on the exterior of the cab


10


so that the lighting assembly


11


is accessible from the exterior of the cab


10


.

FIG. 1A

is an isometric view of an elevator cab comprising a transom assembly mounted on the interior of the cab.





FIG. 2

show is a cross-sectional view of the general concept of the invention. The lighting assembly


11


includes a light refractive sheet


21


that extends along and adjacent to the ceiling


13


of the cab


10


between cab walls


24


and


25


to an inner edge


37


, which may be mirrored.

FIG. 2A

shows a cross-section of another embodiment of the invention, wherein the sheet


21


is adapted for being mounted on a wall surface


24


of the cab


10


.




The refractive sheet


21


has an inner edge


37


(which may be mirrored), upper and lower planar surfaces


46


and


51


, respectively, and an outer edge


39


. The outer edge


39


is adjacent to a light source


30


and attached or adjacent to a reflective guide


42


. The reflective guide


42


directs the light coming from light source


30


into the outer edge


39


. The light is then transmitted into the body of the sheet


21


, where it is scattered randomly throughout. The upper planar surface


46


may be randomly sandblasted (indicated by dots


55


). Light in the body of the sheet then passes out of the lower planar surface


51


into the cab


10


.




The reflective guide


42


has appropriate internal mirroring finish or coating to reflect and direct the light into the outer edge


39


of the sheet


21


.





FIGS. 3A

,


3


B and


3


C show different views of a particular embodiment of the lighting assembly of the invention wherein the refractive sheet


121


extending from the transom


112


has a semi-circular shape. The lighting assembly


111


has a light source


130


and a reflective guide


142


that directs light from the light source


130


into an outer edge


139


of the refractive sheet


121


.




The transom


112


, which houses the lighting assembly


111


contains a perforated face plate


163


that extends vertically from the refractive sheet


121


to the bottom portion


175


of the transom


112


. Light from light source


130


that is not conducted into the outer edge


139


of the sheet


121


is directed through a lens


179


and through the perforated face plate


163


into the cab. The transom tray


112


supporting the light assembly


111


may be dimensioned to any suitable width up to the width of the elevator cab itself so as to fit the transom of the elevator cab.





FIGS. 3A and 3B

show underside views of the transom


112


. The tubular light source


130


, for example a fluorescent light fixture, extends the full width of the assembly


111


. Other lighting sources can include incandescent bulbs or for certain purposes may include emergency battery powered LED light emitters. The perforated face plate


163


does not have to be vertical but can be at another angle with regard to the bottom portion


175


of the tray


112


.




Referring now to

FIG. 3C

, light from the light source


130


is transmitted out of the transom


112


in two ways. First, light from the source


130


is directed by reflective guide


142


into the outer edge


139


of the refractive sheet


121


. The light travels laterally along the sheet into the portion exposed to the interior of the cab. The upper planar surface


146


is treated to prevent light from exiting that surface; for example the upper surface


146


may be randomly sand-blasted, mirrored, painted, etched, routed, or coated with a polished metal foil. Light therefore passes out of the lower planar surface


151


and the inner edge


137


.




The lighting assembly


111


of this embodiment may be fixed in the front corner of an elevator cab, for example as shown in FIG.


1


. In this manner, the transom


112


is accessible from the exterior of the cab, which will ease maintenance. For example, a worker located at an elevator landing may raise the cab so that the top of the cab is at the level of the landing, where the worker can easily change the light source


130


or other components of the assembly


111


from outside the cab. This eases maintenance and does not require the worker to go into the cab compartment.





FIGS. 4A

,


4


B, and


4


C show an additional embodiment of the invention similar to that shown in

FIGS. 3A-C

, but having the inner edge


237


of the sheet


221


aligned and directly above the face plate


263


. This arrangement avoids exposure of the sheet


221


to the interior of the cab so as to prevent damage. Referring to

FIG. 4C

, the arrangement functions similarly to the assembly shown in the

FIGS. 3A-C

, with one exception. In

FIGS. 4A-C

, light conducted from the light source


230


by reflective guide


242


into the outer edge


239


of the sheet


221


travels through the body of the sheet


221


exits at inner edge


237


where it then may be dispersed into the cab. As with the other shown embodiments the upper and lower planar surfaces of the refractive sheet may be treated (painted, mirrored, sand-blasted, or etched) to maximize the intensity of light transmitted from inner edge


237


.




While the invention has been particularly shown and described with reference to particular embodiments, those skilled in the art will understand that various changes in form and details may be made without departing form the spirit and scope of the invention.



Claims
  • 1. An elevator cab lighting assembly comprising:a refractive sheet hiving opposed planar surfaces, an inner edge, and an outer edge, the sheet for being mounted on the cab and having a portion exposed to the interior of the elevator cab; a light source mounted at and conducting light into the outer edge of the sheet; and a transom assembly for housing the outer edge and the light source, wherein light is transmitted from the outer edge through the portion exposed to the interior of the elevator cab.
  • 2. The elevator cab lighting assembly of claim 1, wherein the sheet comprises acrylic.
  • 3. The elevator cab lighting assembly system of claim 2, wherein the sheet is about 0.250 inches thick.
  • 4. The elevator cab lighting assembly of claim 1, wherein the portion exposed to the interior of the cab comprises the inner edge.
  • 5. The elevator cab lighting assembly of claim 4, wherein the portion exposed to the interior of the cab further comprises an area along one of the planar surfaces.
  • 6. The elevator cab lighting assembly of claim 5, wherein one of the planar surfaces is randomly sanded or sandblasted.
  • 7. The elevator cab lighting assembly of claim 5, wherein one of the planar surfaces is etched or routed.
  • 8. The elevator cab lighting assembly of claim 5, further comprising a mirrored layer on one of the planar surfaces.
  • 9. The elevator cab lighting assembly of claim 5, further comprising a painted layer on on one of the planar surfaces.
  • 10. The elevator cab lighting assembly of claim 5, further comprising a mirrored layer on the inner edge.
  • 11. The elevator cab lighting assembly of claim 1, wherein the sheet is adapted for being mounted on a ceiling surface of the cab.
  • 12. The elevator cab lighting assembly of claim 1, wherein the sheet is adapted for being mounted on a wall surface of the cab.
  • 13. The elevator cab lighting assembly of claim 1, wherein the transom assembly further comprises a guide for enhancing conduction of light into the outer edge.
  • 14. The elevator cab lighting assembly of claim 1, wherein the transom assembly is adapted for being mounted on the exterior of the cab.
  • 15. The elevator cab lighting assembly of claim 1, wherein the transom assembly is adapted for being mounted on the interior of the cab.
  • 16. The elevator cab lighting assembly of claim 1, wherein the transom assembly further comprises a perforated face plate for being exposed to the interior of the cab and for diffusing light from the light source into the cab.
  • 17. The elevator cab lighting assembly of claim 16, wherein the transom assembly further comprises a lens mounted between the light source and the face plate.
  • 18. The elevator cab lighting assembly of claim 17, wherein the inner edge is aligned with the face plate.
  • 19. The elevator cab lighting assembly of claim 1, wherein the sheet is rectangular in shape.
  • 20. The elevator cab lighting assembly of claim 1, wherein the sheet is semi-circular in shape.
  • 21. An elevator cab and reflective sheet lighting assembly comprising:an elevator cab having an interior and an exterior; a refractive sheet having opposed planar surfaces, an inner edge, and an outer edge, the sheet for being mounted on the cab and having a portion exposed to the interior of the elevator cab; light source mounted at and conducting light into the outer edge of the sheet; and a transom assembly for housing the outer edge and the light source, wherein light is transmitted from the outer edge through the portion exposed to the interior of the elevator cab.
  • 22. The elevator cab of claim 21, wherein the sheet comprises acrylic.
  • 23. The elevator cab of claim 22, wherein the sheet is about 0.250 inches thick.
  • 24. The elevator cab of claim 21, wherein the portion exposed to the interior of the cab comprises the inner edge.
  • 25. The elevator cab of claim 24, wherein the portion exposed to the interior of the cab further comprises an area along one of the planar surfaces.
  • 26. The elevator cab of claim 25, wherein one of the planar surfaces is randomly sanded or sandblasted.
  • 27. The elevator cab of claim 25, wherein one of the planar surfaces is etched or routed.
  • 28. The elevator cab of claim 25, further comprising a mirrored layer on one of the planar surfaces.
  • 29. The elevator cab of claim 25, further comprising a painted layer on one of the planar surfaces.
  • 30. The elevator cab of claim 25, further comprising a mirrored layer on the inner edge.
  • 31. The elevator cab of claim 21, wherein the sheet is adapted for being mounted on a ceiling surface of the cab.
  • 32. The elevator cab of claim 21, wherein the sheet is adapted for being mounted on a wall surface of the cab.
  • 33. The elevator cab of claim 21, wherein the transom assembly further comprises a guide for enhancing conduction of light into the outer edge.
  • 34. The elevator cab of claim 21, wherein the ransom assembly is mounted on the exterior of the cab.
  • 35. The elevator cab of claim 21, wherein the transom assembly is mounted on the interior of the cab.
  • 36. The elevator cab of claim 21, wherein the transom assembly further comprises a perforated face plate for being exposed to the interior of the cab and for diffusing light from the light source into the cab.
  • 37. The elevator cab of claim 36, wherein the transom assembly further comprises a lens mounted between the light source and the face plate.
  • 38. The elevator cab of claim 37, wherein the inner edge is aligned with the face plate.
  • 39. The elevator cab of claim 21, wherein the sheet is rectangular in shape.
  • 40. The elevator cab of claim 21, wherein the sheet is semicircular in shape.
US Referenced Citations (7)
Number Name Date Kind
3752974 Baker et al. Aug 1973 A
4126210 Martin Nov 1978 A
4223374 Kimmel Sep 1980 A
4704662 Makino Nov 1987 A
4709308 Makino Nov 1987 A
4765076 Sada Aug 1988 A
5862889 Sevilleja et al. Jan 1999 A
Foreign Referenced Citations (10)
Number Date Country
01-308385 Dec 1989 JP
01-313294 Dec 1989 JP
03-042482 Feb 1991 JP
04-020491 Jan 1992 JP
04-032485 Feb 1992 JP
04-106088 Apr 1992 JP
05-193878 Aug 1993 JP
07-111103 Apr 1995 JP
09-100081 Apr 1997 JP
2000-191257 Jul 2000 JP
Non-Patent Literature Citations (2)
Entry
International Search Report issued for International Appln. PCT/US2004/000350.
Written Opinion issued for International Appln. PCT/US2004/000350.