Abstract:
This invention provides a sign image by projecting light through a replaceable pivotable image forming apparatus onto an adjacent surface. The apparatus is contained within a telescoping tube of three locking sections with overlap indicators. The tube is pivotably mounted within a wall or ceiling. The pivotable tube and stencil permits projecting the sign image onto an adjacent inclined surface. The first section has a light source at its outer end and image forming apparatus which provides the sign message. The other two sections each contain a lens for respective image size and focus adjustment by changing the sections overlaps.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates in general to sign apparatus, and relates in particular to emergency sign apparatus within a building required by law to indicate an exit. 
     2. Description of the Related Art 
     There are a variety of signs used in buildings to provide emergency exit signs. These signs are made of a variety of materials, including various metals and plastics, which are mounted on a building ceiling or wall. There are a number of objections to this arrangement. A sign mounted on a wall is subject to damage from a variety of sources, which can even include vandalism. Further, architects consider these signs to be objectionable in appearance. These signs are produced in many different directional arrow configurations that require excessive production of various configurations and can result in potential mistakes in shipping. The proper configuration for any information could be solved by a universal field modified sign adaptable to any configuration. It would be desirable if an exit sign could be concealed completely within a wall or ceiling and still provide the required information, since such an arrangement would eliminate all of the above objections. 
     SUMMARY OF THE INVENTION 
     This invention provides a sign, which is mounted completely within the surface of a wall or ceiling, which projects the desired message on an adjacent surface including a wall, the ceiling or a suspended surface. 
     The sign information is displayed by projecting the desired message on the surface. The projected message is obtained by directing a light source through image forming apparatus. Typical image forming apparatus can include replaceable image lens or stencil. The projection apparatus is mounted within a telescoping tube having three sections. The outer end of the first section mounts the light source and an adjacent image forming apparatus. The second center section, and the third section each mount a lens at the light entrance end. The lenses are arranged such that changing the overlap of the first and second section will change the size of the resulting projected image, and changing the overlap of the second and third section will change the focus of the resulting projected image. The second and third sections have indices along their exterior to respectively indicate the overlap of the first and second sections and the overlap of the second and third sections. Both the overlapped first and second section, and the overlapped second and third section can be locked together at various amounts of overlap. 
     When the image forming apparatus is a stencil, the stencil is pivotably mounted across the tube cross-section. Opposed projections from the stencil apparatus extends through opposed slots in the tube. A scale around one of the slots and the relationship of the projections to the slots indicates the angular relationship of the stencil to a perpendicular pair of axis which are contained in a plane perpendicular to the tube axis. This information assists in orienting the projected image relative to the receiving surface, which will be described further later. 
     The adjacent planar surfaces receiving the image are normally inclined with respect to the projection apparatus. The adjacent surfaces can be a wall, the ceiling or a suspended surface. The mounting apparatus for the tube mounts the tube within a circular opening at an angle with respect to the surface of a wall or ceiling. An outwardly extending flange, which has a central opening, is the only part of the mounting apparatus which is external to the opening. 
     The mounting apparatus is symmetrical about the mounting hole, which permits the apparatus to be mounted at any angle around a line perpendicular to the flange opening. This permits the tube to be mounted with the projected image directed to either the right or left side, upward or downward, or at any angle in between. This permits directing the projected image on an adjacent side wall, the ceiling, or on a suspended surface. Because of the circular dimensions, only a single, relatively small size, circular hole is required to mount both the bracket and projection apparatus. 
     The first section has a light source located at its outer end, with the image forming apparatus mounted adjacent to the light source. The second and third section each have a lens mounted across their respective light entrance ends. Although any image forming means can be used, as indicated above it can be a stencil. The tube is installed at an angle with respect to the wall opening to permit projecting an image upon an inclined adjacent wall, ceiling or suspended surface. 
     In use, the mounting apparatus is oriented and the tube angle adjusted such that the projected image is directed onto the desired adjacent surface. The lenses are then adjusted by changing the relationship between the tube sections to focus the image upon this surface with the required size and the tube sections are locked relative to each other to maintain this desired relationship. 
     Since this apparatus is primarily intended to be used to indicate an exit, it is important that a power line failure not interrupt the projection of the image. The following two back-up power supply arrangements, among other similar arrangements, could be provided to essentially eliminate the possibility of a power interruption. Both would provide direct current power to the light source. 
     One power supply arrangement could use both a trickle charger and battery combination and a separate battery charger, with both being powered by a conventional alternating power source. The battery charger would provide direct current power to the light source and the trickle charger would maintain the battery at full charge. In the event of a power failure a relay could be used to open the battery charger circuit, disconnect the trickle charger from the battery and connect the battery to the light source to provide continuous direct current power for operation. 
     Another power supply arrangement could use a conventional alternating current power source and a back-up alternating current power source. Here the back-up could be either an engine-generator combination, or a battery-inverter combination with either providing alternating current of the same frequency and voltage as the conventional source, and arranged to turn on automatically upon failure of the conventional power source. A relay would switch from the conventional power source to the back-up source upon power failure, such that either of the above back-up power source arrangements would provide system power. A battery charger, which would normally be connected to the conventional power source, upon failure of the conventional power system, would be switched by a relay to the back-up source, such that either active source would provide direct current power to the light source. 
     Providing a back-up power supply arrangement similar to either of those described above, would insure that the projected message would probably never be interrupted. 
     Since the message is provided by projection, it can be made any desired size. Further, since a back-up power source arranged as those described above, could be provided for the event of a power line failure, it is extremely unlikely that there will ever be a failure in displaying the message. The total concealment of the sign apparatus, with only the exception of the flange, eliminates the problems with previous signs as to their vulnerability to damage and their appearance. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of the present sign apparatus mounted within a ceiling; 
     FIG. 2 is a side view of a portion of the interior of a tube within a cut-out region; 
     FIG. 3 is a detail of an image forming apparatus; 
     FIG. 4 is a top view of a portion of the tube; 
     FIG. 5 is a top view of a flange; 
     FIG. 6 is a side view of the mounting bracket; 
     FIG. 7 is a cross-section along  7 — 7  of FIG. 6; and 
     FIG. 8 is a bottom view of the mounting bracket, the flange and a portion of the tube. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows exit sign apparatus  10  mounted within a ceiling  12 . A mounting bracket  14  secures a tube  16  pivotably in place by apparatus which will be described later. Flange  18  attached to bracket  14  is the only external part. 
     Tube  16 , which is telescoping, is made up of a first section  22 , a second section  24 , and a third section  26  all extending along a central axis of tube  16 . Tube  16  contains a light source  28  such as a high intensity LED mounted at the outer end of first section  22 . First section  22  has an angular scale  30  and opposed slots  31 . The purpose of scale  30  and slots  31  will be described later. 
     First section  22  and second section  24  have a first lock  32 , and second section  24  and third section  26  have a second lock  36 . Second section  24  has a first lineal scale  34 , and third section  26  has a second linear scale  38  along its length. The purpose of these locks and scales will be described later. 
     Case  40 , is provided for the system power supply, is attached to the rear of mounting bracket  14  by a bolt and nut  42 , through aligned holes in the case and bracket, not shown. Arrangements for the power supply, contained in case  40 , were described above. Cable  58  is provided to connect a power supply in case  40  to external power source(s) and cable  60  from the case to light source  28  provides power from the case to the light source. 
     FIGS. 2,  3  and  4 , show tube  16 , image forming apparatus consisting of a stencil  44 , first lock  32 , second lock  36 , light source  28 , a first lens  46  mounted across the light entry end of second section  24 , a second lens  48  mounted across the light entry end of third section  26 , and pin  50 , which provides a two-axis pivot point for image forming apparatus  44 . Pin  50  extends through opposing slots  31 , and has a pointer  501  mounted perpendicular to the end adjacent to angular scale  30 . Pointer  501  and angular scale  30  indicates the angle of image forming apparatus  44  with respect to tube  10  along one axis, and the location of the pointer within slots  31  indicates the angle along the second axis. This arrangement permits inclining the image forming apparatus  44  to conform to the angular relationship of the adjacent image receiving surface whether a wall, the ceiling or a suspended surface. 
     Image forming apparatus  44  contains the message “EXIT” in stencil form and has opposed indicator “V” shaped cut-outs on opposite sides to indicate a right or a left exit. Masks  441  and  442  are sized to cover the opposed direction indicators and are pivoted about rivets to permit covering or uncovering the indicators. The solid outlines of masks  441  and  442  indicate the covered positions and the dashed outlines indicate the uncovered positions. This arrangement provides means for customizing the sign in the field to select either a right or left exit indication by merely pivoting right or left masks  441  or  442  about its corresponding rivet to cover the adjacent V shaped cut-out. The rivets are arranged to be tight enough to secure masks  441  or  442  in the desired position against gravity. Image forming apparatus  44  containing other messages can also be substituted. Further, other image forming means can be mounted in the same location in the same way to permit changing its angular relationship with respect to tube  10 . 
     First lock  32  is made up of bolt  321 , lock washer  322  and nut  323 . Bolt  321  is affixed to and extends outward through a hole in second section  24 , not shown, then extends through slot  324  in first section  22 . Slot  324  permits positioning first section  22  and second section  24  at different amounts of overlap. When nut  323  is secured over lock washer  322  and tightened on bolt  321 , first section  22  is locked to second section  24 . 
     A second lock is also made up of a bolt  361 , a lock washer  362  and a nut  363 . Bolt  361  is affixed to and extends outward through a hole in third section  26 , not shown, then extends through slot  364  in third section  26 . Slot  364  permits positioning third section  26  and second section  24  at different amounts of overlap. Lock  36  operates in the same manner as lock  32 . 
     As described earlier, changing the overlap between first section  22  and second section  24 , shown by first lineal scale  34 , will change the size of the projected image, and changing the overlap between the second section  24  and the third section  26 , shown by lineal scale  38 , will change the focus of the projected image. 
     FIGS. 5,  6 ,  7  and  8  show mounting bracket  14  with its attached flange  18  and its relationship to tube  16 . Mounting bracket  14  has two opposing holes  141 , a side opening  142  and a rear surface  143 . 
     Post  56 , mounted on the end of tube  16 , engages opposed holes  141  in mounting bracket  14  which permits pivoting tube  16 . Post  56  is secured in place by friction secured push on connectors  561 . Opening  142 , in mounting bracket  14 , provides pivoting space for tube  16  to permit changing the angular relationship between the tube and the surface of ceiling  12 . This permits inclining tube  16  at the proper angle to project an image on a selected adjacent surface. 
     In use, when a stencil provides the message source, first the proper direction indication is provided by masking one of the AV@ shaped stencil indicators by pivoting the proper mask  441  to indicate the desired exit direction. The mounting bracket  14 , containing apparatus  10 , is then positioned within a wall or ceiling, as shown in FIG. 1, and the proper power connections made. With power provided to the apparatus, the inclination of tube  16  is then adjusted until the projected image is positioned at the desired location on the desired adjacent receiving surface. The projected image is carried in the light beam from source  28  traveling along the axis of tube  16 . The angle of the image forming apparatus  44  is then adjusted, using angular scale  30  and the location of pin  50  within slot  31  and using the location of pointer  501  versus angular scale  30 , to assist in acutely angling tube  16  with respect to ceiling  12  to place the projected image at the desired point on the wall. First lock  32  is then loosened and the overlap of sections  22  and  24  adjusted, using first lineal scale  24  as an aid, until the desired size image is obtained, whereupon the lock is tightened. Second lock  36  is then loosened and the overlap of sections  24  and  26  is adjusted, using second lineal scale as an aid, until the desired focus is obtained. 
     Once this adjustment is complete, light from source  28  will pass through apparatus  44  along the axis of tube  16  at an acute angle to ceiling  12 . The pattern in apparatus  44  appears in focus and with the size desired on the surface against which the light from source  28  falls. 
     This apparatus, with the exception of flange  18  is located totally within ceiling  12 . The ability to change the inclination, the size and focal length of the projected image permits projecting an image of any desired size on adjacent walls, ceiling or suspended surfaces. The sign message can be changed by merely substituting new apparatus  44  with a different message. The use of suitable power sources and either suggested power supply would essentially eliminate the problem of power failure, and the possibility of using either a battery or a separate power system for one emergency back-up system would provide additional flexibility. This arrangement permits field changes of the sign message and/or direction indication, eliminates the problem of damage or vandalism of the sign proper, and provides an enhanced appearance. 
     It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.