Display sign assembly

A lighted display sign having a main frame or cabinet for supporting a light source and one or more sign faces characterized by a decorated sheet of flexible translucent material such as that manufactured under the trademark PANAFLEX. The sign face is mounted on a removable face frame comprising a perimeter member and a plurality of spaced apart brace members connected at their opposite ends to opposed longitudinal portions of the perimeter member. The brace members stand off from the plane of the sign face to eliminate perceived shadows on the sign face from the light source. The sign facing is attached to the perimeter frame by a plurality of spaced apart threaded fasteners which secure the facing material to a surface of the perimeter member which is opposed to and spaced from the front surface of the face frame coplanar with the decorated face. The facing material is suitably tensioned prior to installation of the tapping type fasteners by stretching the facing material over the frame and supporting the material in the stretched condition while the fasteners are installed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention pertains to lighted and unlighted display signs 
having improved means for attaching a flexible sign face to a frame and 
further wherein the frame is particularly adapted for single and double 
faced backlighted signs. 
2. Background Art 
In the art of display sign structures, it is important to provide a 
structure which is economical and light in weight but is capable of 
withstanding environmental effects including relatively high wind loads. 
In order to minimize the supporting structure for various types of display 
signs, a number of improvements in sign structures have been developed, 
including the provision of lightweight flexible sign faces formed of 
translucent plastic. One type of signal face which has been commercially 
developed is manufactured under the trademark PANAFLEX. This type of sign 
facing requires a substantially rigid support frame to which the facing 
may be fastened and stretched relatively tight to maintain proper face 
tension. 
The conventional manner of mounting flexible translucent sign faces such as 
the PANAFLEX brand, requires a relatively complicated clamping arrangement 
for securing the perimeter of the face to the sign frame or body and for 
adjusting the tension in the face at installation. In order to improve the 
appearance of display signs using the PANAFLEX brand facing and standard 
mounting structure, additional relatively complicated framing is required 
to support and also conceal the face mounting structure. Moreover, the 
type of structure heretofore provided for mounting the PANAFLEX type 
flexible sign facing also requires additional space when retrofitted to 
existing sign cabinets and does not lend itself to sign structures which 
are easy to assemble initially and are readily serviceable for changing 
lighting or performing other service operations. 
It has become highly desired to provide simpler mounting structure for 
flexible sign facing, particularly for backlighted signs wherein the 
facing support structure should be relatively uncomplicated, compact, and 
lightweight without sacrificing strength and the ability to withstand high 
wind loads. The present invention provides these desiderata and also 
provides an improved sign frame which is adapted for improved backlighting 
of single or multi-faced signs using translucent flexible sign facing. 
SUMMARY OF THE INVENTION 
The present invention provides an improved mounting arrangement for 
flexible sign facing which is structurally simple and provides for 
suitable tensioning of the sign facing without requiring as much space and 
numbers of components as required by prior art sign structures. 
The present invention is particularly adapted to provide an improved 
mounting frame arrangement for flexible plastic sign facing of the type 
manufactured and sold under the trademark PANAFLEX and similar types of 
sign facing wherein a relatively mechanically simple mounting frame is 
provided which, together with an improved technique for applying the 
facing to the frame, substantially reduces the cost and complexity of the 
sign structure. 
In accordance with one aspect of the present invention, there is provided a 
support frame for flexible sign facing comprising a lightweight aluminum 
tube of preferably square or rectangular cross-section to which the 
flexible facing is attached by spaced apart self-threading screws or the 
like which are threadedly engaged with the frame at suitable intervals 
along the frame, and which in conjunction with an improved assembly 
process, eliminates the need for complicated face tensioning structure. 
Further in accordance with the present invention, there is provided an 
improved display sign having a simplified framing or retainer structure 
covering the mounting frame for the flexible facing material. The facing 
support frame, as well as the associated covering and retaining structure 
together with the main sign frame or cabinet, may be manufactured of 
standard structural metal shapes without requiring special extrusions and 
framing components for supporting the flexible facing and forming the 
support structure therefor. 
In accordance with another aspect of the present invention, there is 
provided a sign support structure for backlighted translucent flexible 
facing which includes requisite mechanical strength for supporting the 
facing under required tension and wherein the location of light sources 
within the sign cabinet do not effect the lighting of the sign facing by 
producing shadows or uneven light distribution. 
The present invention still further provides an improved sign support 
structure which is easily serviceable for changing lamps and for changing 
the sign facing itself without requiring complicated procedures for 
removing portions of the sign structure during exchange or replacement of 
the sign facing. 
In accordance with yet another aspect of the present invention, there is 
provided an improved method of mounting a flexible sign facing or the like 
to a support frame therefor, which provides suitable tensioning of a 
flexible sign facing material without requiring complicated tensioning 
procedures and associated structure. 
Those skilled in the art will recognize the superior features and 
advantages of the present invention upon reading the detailed description 
which follows in conjunction with the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In the description which follows and in the drawings, like parts are 
identified with the same reference numerals, respectively. 
Referring to FIG. 1 of the drawings, there is illustrated a display sign of 
the type which may be used, for example, to identify a retail store 
location or the like. The exemplary sign, generally designated by the 
numeral 10, is of the type which may be mounted on a vertical wall or 
other support structure, not shown, and may be connected to suitable 
electrical conductors to provide illumination from a source within the 
interior of the sign structure which may include a plurality of lamps 
arranged to provide suitable lighting without shadows or "hot" spots 
visible on the sign face 12. 
The sign face 12 is preferably of a flexible plastic sheet which is 
translucent and which is printed with suitable indicia so that when the 
light source is placed behind the face an attractive lighted display is 
provided. The flexible sign facing, one type of which is manufactured 
under the trademark PANAFLEX by 3M Corporation, Minneapolis, Minn., is of 
a suitable material which may be stretched on a support structure and 
mounted on a cabinet which contains the light sources. 
In accordance with the teaching of the present invention, the support 
structure for the face 12 is of an improved design which is more easily 
fabricated, requires less space than prior art supporting structure, may 
be retrofitted to existing sign cabinetry, and may provide for a lighter 
weight and more economically fabricated sign. Referring also to FIG. 2, 
the improved display sign of the present invention includes a main cabinet 
or frame 14 which may be formed of a suitable extruded aluminum structural 
shape as indicated, or may be made up of conventional aluminum or other 
metal shapes fabricated into a frame assembly. The frame 14 includes a 
front outwardly projecting peripheral flange 16 and an inwardly extending 
peripheral flange 18 which extends around the perimeter of the frame. The 
backface of the frame 14 may comprise a relatively large plate member 20 
and a suitable number of spaced apart column members 22, one shown in FIG. 
2, which may be formed of aluminum angle or T-section, for example. The 
column members 22 are preferably braced by members 24 having a similar 
cross-sectional shape. The frame member 14 may include integrally formed 
wall portions 26 and 28, as shown in FIG. 2, forming together with a cover 
30 enclosures for electrical wiring and lamp sockets or the like, not 
shown. Although the sign 10 is shown as having oval ends, the frame 14 may 
be rectangular or other shapes and the configuration of the frame 14 at 
the end portions may be same or of a similar shape as that illustrated by 
the cross-sectional views of FIGS. 2 and 3. 
In accordance with the present invention, the flexible facing 12 of the 
sign 10 is mounted on a face or subframe generally designated by the 
numeral 34. The frame 34 is preferably fabricated of, for example, 
aluminum tubing of square or rectangular cross-sectional shape and formed 
in the general shape of the outline of the sign 10 as indicated. The face 
frame 34 includes the perimeter member 36, as well as a plurality of 
intermediate somewhat C-shaped brace members 38 suitably spaced apart and 
interconnecting the upper and lower longitudinal frame portions 40 and 42, 
FIG. 1, to provide a substantially rigid but lightweight frame structure 
which satisfies additional requirements in accordance with backlighted 
sign structures as will be explained further herein. 
Although the face 12 is required to be stretched relatively tight on the 
face frame 34, sufficient structural integrity may be obtained, for 
example, with a frame approximately 21 feet long by 7 feet wide using one 
inch square aluminum tubing meeting ASTM Specification 6063-T5. The 
C-shaped brace members 38 may also be of one inch square aluminum tubing 
or larger, and as illustrated for a sign according to the aforementioned 
dimensions, a total of four equally spaced apart brace members are 
suitable. 
Contrary to the requirements believed heretofore necessary for properly 
mounting and tensioning the face 12, in accordance with the present 
invention, the face may be stretched over supporting surfaces 35 and 37 of 
the frame member 36 and suitably fastened to its backside surface 46, FIG. 
2, by spaced apart fasteners 48 which may be, for example, preferably of 
the hexagon washer head tapping screw type. The face 12 is preferably 
aligned on the frame member 36 and fastened along the backside of one 
longitudinal portion 40, or 42 and then stretched around the opposite 
longitudinal portion by a suitably modified gripping tool which, for 
example, could comprise a pair of locking pliers having modified jaws of 
suitable width to prevent tearing the face material during the tensioning 
operation. As the material is stretched around the opposite frame member 
portion and held by a suitable number of the aforementioned modified 
pliers, the tapping screws 48 are applied at suitably spaced intervals to 
secure the facing 12 to the frame member 36. This method has been suitably 
developed and eliminates the rather complex structure which is used in 
conventional mountings of flexible plastic sign facings of the type 
referred to herein. 
As illustrated in FIG. 2, the face frame 34 is preferably mounted within 
the periphery of the flange 16 and is, of course, suitably dimensioned to 
be a relatively close fit within the perimeter of the flange. The face 
frame 34 is preferably provided with a number of spaced apart lightweight 
open hinges 50 secured to the face frame 34 and to the main frame 14 using 
suitable threaded fasteners. As illustrated in the drawing FIG. 2, the 
face 12 is provided of sufficient peripheral dimension to be stretched 
over three adjacent sides of the frame member 36 to provide suitable 
support for the face material. Although fastening to the backside 46 of 
the frame member 36 is preferred, as illustrated, it is also possible to 
consider the arrangement whereby the fasteners would be connected to the 
outer peripheral edge of the frame member 36 or even the front face 
although these arrangements may be less suitable than that which is 
illustrated. With the simplified framing and support structure for the 
face 12 in accordance with the present invention, the peripheral retainer 
or shield may also be eliminated or, if it is desired to maximize the 
aesthetic effect of the sign, a peripheral L-shaped face retainer member 
may be fastened over the face frame 34 and to the main frame 14, if 
desired. In FIG. 2, such a retainer member is illustrated with phantom 
lines and designated by the numeral 47. 
Referring to FIGS. 1 and 2, the improved sign structure of the present 
invention is further characterized in that the perimeter frame member 36 
of the face frame 34 is braced by the plurality of spaced apart C-shaped 
brace members 38 which are preferably welded at their opposite ends, 
respectively, to the opposed longitudinal portions 40 and 42 of the 
perimeter member. The brace members 38 are configured such that a major 
portion of each of the members stands off from the plane of the face 12 
sufficiently to eliminate any perceived shadow from a light source 
disposed behind the brace members with respect to the face 12. The brace 
members 38 may be formed of suitable metal structural shapes and are 
preferably fabricated of square cross-section aluminum tubing of the same 
size used for the frame member 36. 
Referring particularly to FIG. 3, there is illustrated somewhat 
schematically the placement of the light source for backlighting the face 
12. The light source for the sign 10 is characterized by a plurality of 
elongated lamps 56 which may be of the fluorescent tube type and which are 
disposed in an array of parallel side-by-side tubes running longitudinally 
and supported at their opposite ends within the frame 14 by suitable 
socket assemblies 58. The lamps 56 are arranged in somewhat overlapping 
relationship near the center of the sign face to provide sufficient 
illumination for the center of the sign. The opposed curved ends of the 
exemplary sign 10 are also provided with generally parallel spaced apart 
lamps 60, 62 and 64, as illustrated, which are suitably supported by 
socket assemblies mounted on the main frame 14. The lamps 56 are spaced 
between the backwall 20 of the frame 14 and the brace members 38, thereby 
placing the light source for the face 12 such that the brace members are 
disposed between the light source and the sign face. However, by providing 
the brace members 38 configured such that they stand off substantially 
from the plane of the sign face 12, there is virtually no perceived shadow 
on the face. 
Those skilled in the art of display signs will appreciate that the 
arrangement of the perimeter face frame 34 and the bracing therefor, 
together with the improved means for mounting the flexible face sheet 
represents a substantial improvement in lighted display sign structures. 
The construction of the face frame 34 and the method of fastening the 
flexible sheet facing to the frame, considerably reduces the cost of 
fabricating relatively large display signs of various types. The weight of 
the sign is reduced, thereby simplifying the sign mounting structure and 
the space required for the sign face itself is also less than prior art 
arrangements for supporting flexible sheet facing material. 
Display signs following the teaching of the present invention may take 
various forms and shapes without departing from the scope and spirit of 
the inventive concept. Referring to FIG. 4, an alternate embodiment of the 
present invention is illustrated and comprises a double faced sign 
generally designated by the numeral 70. The sign 70 includes a main frame 
72 formed of conventional steel or aluminum angle sections 73, 75 and 77 
suitably welded together and braced by a plurality of transverse flat 
members 76. The frame 72 is adapted to be mounted on a vertical standard 
78. A sheet or extruded metal filler member 71 forms an enclosure for the 
frame 72 and the opposite end portions of the sign 70. A plurality of 
generally vertically disposed lamps, not shown, may be positioned within 
the frame 72 for illuminating opposed sign faces generally designated by 
the numerals 82 and 84. Each of the sign faces 82 and 84 includes a frame 
comprising a perimeter member 86 and a plurality of spaced apart brace 
members 88 extending between the longitudinal portions of the perimeter 
member and standing off from the plane of the faces of the sign in a 
manner similar to the braces 38 for the frame member 36. The 
aforementioned array of lamps is disposed between the sets of braces for 
each of the faces 82 and 84 and provides sufficient illumination of the 
inner side of the sheets of flexible material comprising the faces such 
that the faces are illuminated without any shadows occurring thereon from 
the brace members. In the embodiment of FIGS. 4 and 5, the flexible facing 
sheets for each of the faces 82 and 84 are secured to the perimeter 
members in the same manner as the embodiment of FIG. 1. Moreover, the 
faces may also be provided with a retainer or trim flange, not shown, 
disposed around the periphery of the faces in the same manner as the 
embodiment disclosed in FIGS. 1 through 3. 
Those skilled in the art will also appreciate that the improved sign face 
arrangement according to the present invention may be retrofitted to 
existing sign frames and cabinet structures. Since the perimeter member 
and the bracing therefor comprising the face frame may be easily 
fabricated in a variety of shapes and since the fastening of the flexible 
sheet facing material to the face frame according to the present invention 
is greatly simplified, sign faces of a wide variety of shapes and sizes 
may be provided in accordance with the teaching of the present invention. 
Although specific embodiments of the invention are disclosed herein, those 
skilled in the art will recognize that various substitutions and 
modifications may be made without departing from the scope and spirit of 
the appended claims.