Wooden suspended ceiling system

A wooden suspending ceiling system is disclosed comprising a plurality of parallel wooden runners extending in one direction, and a plurality of parallel wooden cross members supported by the runners and extending in a second direction perpendicular to the runners defining a generally rectangular grid system having a plurality of openings therein. Ceiling panels, lighting fixtures, or air vents are supported by the runners and cross members defining the rectangualr grid system and closing the openings therein. The runners and the cross members have an upper face and a bottom face, with the bottom face being viewable from below. The upper face of both the runner and cross members comprises a central portion with a groove on each side of the central portion, and with a lip outboard of each of the grooves. The inner surface of the lip defines the outer surface of the groove on each side of the central portion, and with a lip outboard of each of the grooves. The inner surface of the lip defines the outer surface of the groove, and the outer surface of each of the lips defines a vertical side of the runner or cross member. The cross member has an integral hook extending out beyond each end thereof for cooperating with an adjacent side, lip, and groove of a respective runner thereby to positively interconnect the cross member to the runners and to support the cross members on the runners.

BACKGROUND OF THE INVENTION 
This invention relates to a wooden suspended ceiling system, and more 
specifically to the grid system of such a wooden suspended ceiling system 
for supporting ceiling panels, lighting fixtures, or air vents in a 
suspended ceiling. 
Generally, in modern office buildings, each floor of the building, prior to 
being subdivided and occupied by tenants, consists of a finished floor and 
a continuous, suspended ceiling having a plurality of fluorescent (or 
other) lighting fixtures spaced in the ceiling at desired intervals. 
Additionally, heating, ventilating, and air conditioning (HVAC) outlets 
are provided at desired spaced locations within the suspended ceiling 
system. The suspended ceiling typically comprises a metal grid consisting 
of longitudinal parallel runners spaced apart from one another a desired 
distance, separated by cross members at desired intervals with the runners 
and cross members being perpendicular to one another and defining a 
plurality of generally rectangular openings between the perpendicular 
runners and cross members. These openings are of a standardized size 
(e.g., two feet.times.two feet) such that modularized ceiling panels, 
lighting fixtures, or ventilation outlets may be dropped in place within 
the openings of the grid systems at desired locations and supported by the 
ceiling grid system. Typically, the ceiling grid system is suspended below 
the roof or floor immediately thereabove by means of suspension wires 
interconnecting the grid system to the structure thereabove, with the 
suspension wires being adjusted in such manner so as to ensure that the 
ceiling is suspended in a level position at a desired height above the 
floor below. Typically, in modern commercial buildings, a sufficient space 
is provided between the suspended ceiling and the structure thereabove so 
as to permit HVAC ducts, electrical wiring, plumbing pipes, etc., to 
readily be mounted between the suspended ceiling and the floor or ceiling 
structure thereabove. 
Upon constructing a new office building, once a tenant leases or occupies 
the space, partitions within the building, typically consisting of 
vertical metal studs faced with dry wall sheathing on each side thereof, 
are erected on the floor at desired locations and are secured to the floor 
so as to sub-divide the space into a desired interior arrangement. 
Suitable doors and other fixtures are incorporated in the wall partitions. 
However, the partitions are typically not connected to the suspended 
ceiling and, in fact, the suspended ceiling may, at least in part, rest or 
bear on the upper surfaces of the partitions. In the event one wishes to 
change the floor plan of the building, it is a relatively simple and 
inexpensive matter to remove the partitions and to erect others without 
having any effect on the suspended ceiling system. Oftentimes, it is a 
relatively easy matter to relocate lighting fixtures and air vents within 
the ceiling grid structure so that rooms defined by the subsequently 
erected wall partitions serve desired occupied areas or rooms within the 
building. 
Reference may be made to such patents as U.S. Pat. Nos. as 2,971,617, 
2,994,113, 3,013,644, 3,329,387, 3,385,021, 3,783,771, 3,785,110, 
4,019,300, 4,040,758, and 4,047,348, which show a variety of conventional 
prior art suspended ceiling systems utilizing intersecting, perpendicular 
metal grid members. While these prior art suspended ceiling systems worked 
well for their intended purposes, and while they were of rigid 
construction and were relatively easy to interconnect with one another, 
the bottom faces of the grid members were typically readily viewable from 
below by occupants within a room. 
Typically, the ceiling panels utilized with such typical prior art metal 
grid systems were of a fibrous composition material, and were so 
manufactured as to have a finished bottom face with flanges or shoulders 
extending outwardly from the periphery of the ceiling panel, and with the 
bottom face of the ceiling panel being positioned below these outwardly 
extending flanges such that when the ceiling panel is dropped into 
position from above within a respective grid opening in the metal grid 
suspended ceiling system, the ceiling panel would be readily received and 
supported by the intersection grid members with the bottom faces of all 
the ceiling panels being substantially coplanar, and with the bottom faces 
of the grid members appearing as batt members separating adjacent ceiling 
panels. 
It had long been recognized in many commercial buildings that the 
appearance of such utilitarian ceiling systems utilizing metallic grids 
resulted in a highly practical ceiling system, but did not enhance the 
appearance of a room, particularly where an upscale interior finish was 
desired. 
In an effort to enhance the appearance of such metal suspended ceiling grid 
systems, simulated wood grain risers or grid members were utilized (i.e., 
metal grid members having a wood grain finish imprinted thereon or adhered 
thereto was utilized), as shown in U.S. Pat. No. 3,583,119. 
It was also known to utilize imitation wood beams, as shown in U.S. Pat. 
No. 3,557,506, which were fastened to the bottom portions of the 
conventional metal grid suspended ceiling systems. 
Still further, as shown in U.S. Pat. Nos. 4,454,700, 4,281,498, 4,367,616, 
4,452,021, 4,464,876, and 4,525,971, a variety of wood beam suspended 
ceiling systems have been proposed. Typically, like metal grid suspended 
ceiling systems, these prior art wooden suspended ceiling systems utilized 
elongate runners with perpendicular cross members. However, these wooden 
suspended ceiling systems required a variety of metallic clips or other, 
separate fastening members for rigidly interconnecting the cross members 
to the runners. Typically, these connecting members were made of metal and 
were required, either in the field during installation or at the factory 
prior to installation, to be separately attached to the cross members and 
to the runners. 
SUMMARY OF THE INVENTION 
Among the several objects and features of the present invention may be 
noted the provision of a wooden suspended ceiling system in which the main 
runners and the cross members are of solid wood construction, and in which 
the cross members may be positively interlocked with the main runners 
without the use of auxiliary clips or other fastening devices; 
The provision of such a wooden suspended ceiling system which accommodates 
conventional ceiling panels, with the exposed parts of the wooden ceiling 
grid system exposed thereby to enhance the aesthetics of the ceiling from 
within the room; 
The provision of such a wooden suspended ceiling system in which the means 
for interlocking the cross members and the runners are integral with the 
cross members; 
The provision of such a wooden suspended ceiling system which may be 
readily installed in substantially the same manner as prior metal grid 
suspended ceiling systems; 
The provision of such a wooden suspended ceiling system which may be 
arranged to accommodate and support conventional lighting fixtures; 
The provision of such a wooden suspended ceiling system which, with a 
minimum amount of cutting, may be adapted to fit within a room of varying 
dimensions and having irregular walls, internal posts, or columns; 
The provision of such a wooden suspended ceiling system in which the cross 
members also serve as spacers for the main runners; 
The provision of such a wooden suspended ceiling system in which crown and 
cove moldings may be utilized to enhance the treatment of the intersection 
of the walls and ceiling of a room; 
The provision of such a wooden suspended ceiling system which, in place of 
conventional flat composite ceiling panels, may be utilized in combination 
with wooden vaulted panels thereby resulting in a wooden vaulted ceiling; 
and 
The provision of such a wooden suspended ceiling system which is easy to 
install, which is of relatively low cost, and which substantially enhances 
the aesthetic appearance of the ceiling. 
Other objects and features of this invention will be in part apparent and 
in part pointed out hereinafter. 
Briefly stated, a wooden suspended ceiling system of the present invention 
is suspended at a desired level from an overhead structure of a building, 
such as the bar joists of the roof structure or the immediately adjacent 
above floor of the building. The suspended ceiling system of the present 
invention comprises a plurality of parallel wooden runners extending in 
one direction, and a plurality of parallel wooden cross members supported 
by the runners and extending in a second direction, thus defining a 
plurality of openings. A ceiling panel is supported by the runners and 
cross members and thus closes the ceiling openings. The runners and the 
cross members each have an upper face and a bottom face, with the latter 
being viewable from below within the room. The upper face of both the 
runners and the cross members comprises a central portion, a groove on 
each side of the central portion, and a lip outboard of the groove, with 
the inner surface of the lip defining the outer vertical surface of the 
groove. The vertical surface of each of the lips defines the sides of the 
runners or cross members. Each of the cross members has an integral hook 
extending out beyond the end thereof for cooperating with an adjacent 
side, lip, and groove of its respective runner, thereby to positively 
interconnect the cross member to the runner and to support the cross 
member on the runner.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now to the drawings, and particularly to FIG. 1, a wooden 
suspended ceiling system of the present invention is indicated in its 
entirety by reference character 1. Ceiling system 1 comprises the ceiling 
C of a room R of a building, which, for example, may be a large office or 
other commercial building having overhead structure (not shown) above the 
ceiling system. For example, this overhead building structure (not shown) 
may comprise a series of overhead horizontal beams or bar joists which 
support the floor or roof structure thereabove. As is conventional, the 
wooden suspended ceiling system 1 of the present invention is suspended 
from the above-described overhead building construction at a desired 
horizontal level in a manner as will appear Room R further comprises a 
number of vertical walls or partitions 3 defining rooms within the 
building, and each room has a floor 5 located below the ceiling C. As 
indicated at 7, wall 3 has a door located therewithin. Typically, walls or 
partitions 3 in such commercial buildings are secured to floor 5, but the 
top portions of the walls need not be positively joined to the suspended 
ceiling system 1. In fact, in many large office or other commercial 
buildings, an entire floor (or large portions thereof) are finished by 
laying carpet or other floor covering material on floor 5 and by 
installing a complete suspended ceiling system 1 of the present invention 
throughout a large area of the building prior to constructing walls or 
partitions 3. It will be understood that oftentimes the location of walls 
or partitions 3 are at the choice and design of a tenant of the building 
which is not known at the time the building is completed. By having the 
ability to erect walls 3 at substantially any location on floor 5 without 
the necessity of securing the tops of the walls to ceiling system 1 of the 
present invention, a substantially infinite arrangement of walls and rooms 
within the building may be readily realized. 
More specifically, the wooden suspended ceiling system 1 of the present 
invention comprises a plurality of elongate main runners 9 extending 
parallel to one another in one direction and a plurality of cross members 
11 parallel to one another and being perpendicular to the main runners 9, 
with the main runners being spaced apart from one another a predetermined 
distance, and with the cross members 11 also being spaced apart from one 
another a predetermined distance thereby to form a wooden horizontal grid 
system, as generally indicated at 12. The cross members 11 include means, 
as generally indicated at 13, integral with the cross members for 
positively interconnecting or locking the cross members to the main 
runners, and for supporting the cross members on the main runners in the 
above-described grid array 12. In this manner, a pair of adjacent parallel 
main runners 9 and a pair of parallel adjacent cross members 11, spanning 
between the above-noted pair of main runners, define a ceiling panel 
opening, as indicated generally at 15, with the main members being located 
on centers by a predetermined uniform dimension L, and with the cross 
members being located relative to one another on centers by a 
predetermined dimension W. Ceiling panel openings 15 are so sized as to 
receive a ceiling panel, as generally indicated at 17, so as to close 
ceiling openings 15. A flat version of ceiling panel 17 is illustrated in 
FIG. 1. Various vaulted ceiling panels (as will hereinafter be described 
in detail), are illustrated in FIGS. 9 and 13. As indicated at 18, 
fluorescent or other types of lighting fixtures may also be inserted in 
ceiling openings 15 and supported by the wood grid suspended ceiling 
system of theppresent invention at any desired location within ceiling C. 
As indicated generally at 19, means is provided for suspending the grid 
array 12 of wooden suspended ceiling system 1 of the present invention 
from the overhead structure (not shown) of the building. More 
specifically, suspension means 19 is shown to comprise a plurality of 
screw eyes 21, preferably screwed into the upper face of elongate main 
runners 9 at spaced locations therealong. The exact spacing and the number 
of screw eyes required to adequately support the suspended ceiling system 
1 of the present invention from the overhead building construction will 
vary considerably, depending on the size and shape of the room, the type 
and number of lighting fixtures 18, and the type of ceiling panels 17 to 
be supported by the suspended ceiling system. In any event, regardless of 
the number of screw eyes 21 utilized, appropriate suspension wires 23 are 
affixed to the screw eyes and extend vertically for securement to the 
above-mentioned overhead structural members of the building (not shown) 
thereby to support the wooden suspended ceiling system 1 of the present 
invention. 
As above-mentioned, both main runners 9 and cross members 11 are preferably 
milled of solid wood, such as oak, poplar, walnut, or the like, to a 
desired shape and have an upper face and a lower face, as shown in FIGS. 2 
and 3, with the lower face being viewable from below within room R. As 
best shown in FIGS. 5-7, each of the wood members has a central sill 
portion 27 which is centered on and which is generally symetrical with 
respect to the longitudinal centerline of the main runner 9 or the cross 
member 11. Further, each of the wooden ceiling grid members has a groove 
29a, 29b on each side of its central sill 27. A lip 31a, 31b is provided 
outboard of grooves 29a, 29b, with the inner face of the lip constituting 
the outer vertical surface of a respective groove 29a, 29b. This outer 
surface of grooves 29a, 29b is indicated by reference character 33. As 
noted, the upper horizontal faces of lips 31a, 31b are spaced below the 
horizontal surface of central sill 27. The outermost vertical sides 35a, 
35b of each of the wooden members constitute the longitudinal vertical 
sides of either the main runners 9 or the cross members 11. 
As previously indicated, cross members 11 are provided with integral means 
13 for positively interconnecting or locking main runners 9 and cross 
members 11 together. More specifically, this integral locking or holding 
means 13 is shown to comprise a wooden hook end 37 integrally formed on 
each end of cross members 11. Hook end 37 is shown, in FIGS. 5-7, to 
extend out beyond the transverse end 39 of cross member 11 a distance A 
(as shown in FIG. 7), which is substantially equal to (or slightly less 
than) the distance from the outer side 35a, 35b of main runner 9 to the 
outermost vertical edge of center sill 27, as also indicated by dimension 
A in FIG. 5. Hook end 37 further comprises a transverse groove 41 (see 
FIG. 7) formed in the bottom of the hook end 37, with an outermost finger 
43 extending downwardly at the outer end of the hook end. It will be 
appreciated that when the cross member 11 is connected or locked to main 
runner 9, as shown in FIGS. 2, 3, and 5, finger 43 of integral hook end 37 
is received in a respective groove 29a, 29b of main runner 9, and the 
upwardly protruding respective lip 31a, 31b of the main runner is received 
in transverse groove 41 of hook end 37 of the cross member 11. Further, 
the transverse end face 39 of cross member 11 is in face-to-face abutting 
relation with a respective vertical side 35a, 35b of main runner 9. It 
will be understood that the tolerances between hook end 37 of cross member 
11 and grooves 29a, 29b and lips 31a, 31b of main runner 9 are such that 
the hook end 37 has a relatively tight fit as it is received on the main 
member, as shown in FIGS. 2, 3, and 5, so as to ensure that the cross 
members are substantially perpendicular with respect to the main members, 
and so as to substantially prevent sliding movement of the cross members 
lengthwise of the main runners. Additionally, with the upper surface of a 
respective lip 31a, 31b bearing against the upper horizontal edge defining 
groove 41 on hook end 37, and with finger 43 protruding down into and 
being received by the lateral grooves 29a, 29b of the main runner 9, the 
weight of the cross members is supported by the main runners at either end 
of the cross members, as shown in FIG. 2. As is illustrated in FIGS. 2 and 
3, with the cross members 11 connected to main runners 9 by hook ends 37, 
the bottom faces of both the cross members and the main runners are 
substantially coplanar. 
Further, it will be appreciated that a decorative recess 45 may optionally 
be provided in the bottom face of both main runners 9 and cross members 11 
so as to give a sculptured or three-dimensional appearance to a viewer 
within room R looking upwardly at ceiling 1 of this invention, thus 
enhancing the visual perception that the wooden suspended ceiling system 1 
of the present invention is of solid wood. 
It will be appreciated that locking means 13, including hook ends 37, as 
above-described, snuggly fit with their respective main runners 9 in such 
manner that the wooden grid system 12 is maintained in its desired grid 
position, as shown in FIG. 1, with main runners 9 extending parallel to 
one another in one direction, and with the cross members 11 extending 
parallel to one another and perpendicular to the main runners in another 
direction, with the cross members maintaining their predetermined 
distances therebetween, as indicated by dimension L in FIG. 1, so as to 
maintain ceiling panel openings 15 of a predetermined size. However, in 
certain instances, it may be desirable that staples, nails, or other 
fastening devices, as generally indicated at 46 (see FIG. 5), be driven 
through the portion of hook end 37 of cross member 11 into the respective 
upper face of a respective lip 31a, 31b of main member 9, thereby to 
positively interconnect and secure the cross members to the main members. 
Preferably, fasteners 46 are driven through the cross members into the 
main members by means of a pneumatic nailing device (not shown) familiar 
to those skilled in the art such that substantially no momentum or impact 
force is applied to either the cross members or the main runners, as may 
be caused by driving nails 46 into the wood members with a hammer. 
To install the wood grid system 12 of the suspended ceiling system of the 
present invention, the room in which it is to be installed is first 
carefully measured and the grid pattern is layed out so as to allow the 
spaces at the edges of the room to be substantially equal. It is preferred 
that the overhead building structure from which the suspended ceiling grid 
12 is to be suspended (i.e., bar joists) run perpendicular to the 
direction of main runners 9. The reason for this is that upon attaching 
suspension wires 23 to the main members, the suspension wires will have a 
greater tendency to run truly perpendicular from the main members to the 
building support structure (e.g., bar joists), and thus will not apply 
side loads to the ceiling grid system. The main members 9 are suspended 
from the overhead building structure utilizing screw eyes 21 and 
suspending wires 23, and are arranged at their desired spacing W, as shown 
in FIG. 1, preferably by using cross members 11 as spacing guides. With 
the main members 11 thus suspended from the overhead building structure, 
and with all of the main members 9 being substantially at their desired 
horizontal position, cross members 11 are manually installed between the 
main members at their desired spacing from one another in the manner shown 
in FIG. 2. It will be understood that the cross members 11 may be manually 
pressed into locking engagement with the main members, utilizing the 
integral hook ends 37 on the cross members being received in side grooves 
29a, 29b of the main members. As above described, optional, but in certain 
instances preferable, nails 46 may be driven into the cross members and 
into the main members (as shown in FIG. 5) thereby to even more securely 
join the cross members to the main members when the cross members and the 
main members have been accurately positioned with respect to one another. 
After completion of installation of the grid system 12, appropriate ceiling 
panels 17 and lighting fixtures 18 may be inserted in place from above 
such that the edges of the ceiling panels and edges of the lighting 
fixtures are supported on the upper faces of lips 31a, 31b of both the 
main runners and the cross members. 
Referring now to FIG. 9, another embodiment of a ceiling panel is shown, 
indicated in its entirety at reference character 47. More specifically, 
ceiling panel 47 is a so-called vaulted or three-dimensional ceiling 
panel, having an outer peripheral frame comprising inclined cove molding 
wood members 49 with miter cut corners such that the sides of vaulted 
ceiling panel 47 have a lower vertical outer portion and an upwardly, 
inwardly inclined outer portion with a decorative molded inner face. On 
the upper edges of the mitered cove molded sides of the vaulted ceiling 
panel, a flat upper panel 51 is secured thereto. Preferably, the sides and 
upper panel 51 of vaulted ceiling panel 47 are made of solid wood and are 
conventionally finished. Vaulted ceiling panel 47 is sized so as to be 
lowered into place within a respective ceiling panel opening 15 within 
ceiling grid system 12 in place of the flat or planar ceiling panels 17, 
as illustrated in FIG. 1. Thus, the ceiling system 1 of the present 
invention utilizing vaulted ceiling panels 47 gives a distinctively 
different appearance to viewers within room R, and adds appreciably to the 
aesthetics of the ceiling. Of course, it will be recognized that lighting 
fixtures 18 may be installed at desired locations within grid system 12 in 
the manner heretofore described. 
Referring to FIG. 13, still another embodiment of a ceiling panel is 
illustrated in its entirety as reference character 53. Ceiling panel 53 is 
a vaulted ceiling panel, similar to vaulted ceiling panel 47, with the 
exception that upper panel 51 of ceiling panel 47 has been replaced by a 
wooden lattice upper panel member 55. This gives yet another aesthetically 
different appearance. 
Referring to FIG. 1, it will be appreciated that in certain applications, 
it is necessary to treat the intersection of wooden suspended ceiling 
system 1 and the vertical upper reaches of walls 3 in such a manner that 
the ends of the main runner members 9 and the outer ends of the cross 
members 11 are adequately supported, and yet such that ceiling openings 15 
at the edges of the room may be varied in the event the room is not of 
such dimensions that an even number of full size ceiling panels, either in 
length or width, can be accommodated. To accomplish this, a variety of 
molding members, as illustrated in FIGS. 10, 11, and 4, may be utilized at 
the intersection of ceiling system 1 in the upper reaches of walls 3. 
More particularly, referring to FIG. 10, one manner of supporting the ends 
of ceiling system 1 is shown in which an elongate nailing block 57, 
typically of 2.times.3 lumber or the like, is secured, as by means of 
nails or the like, to wall 3 at a prescribed elevation above floor 5. A 
firring strip 59 is secured to nailing block 57, and an appropriate main 
runner 9 for a prescribed length thereof is nailed to the bottom face of 
firring strip 59 such that the innermost vertical edge of firring strip 59 
is in vertical alignment with the outermost edge of central portion 27 of 
runner member 9 nailed to the firring strip such that the hook end 37 of 
cross members 11 may be secured thereto thereby to support the outer ends 
of the outermost cross tees 11. Further, a crown molding strip 61 may be 
nailed at an incline with respect to wall 3 and the bottom faces of nailer 
57 and main runner 9 so as to give a finished crown molding appearance to 
the room at the intersection of ceiling C and wall 3. 
Referring now to FIG. 11, another variation of the molding treatment 
utilized to support the outer ends of ceiling system 1 of the present 
invention, is shown in which lengths of panel mold cove strips 63 are 
secured (nailed) to wall 3 at a predetermined elevation around the room. 
In this manner, runners 9 and cross tees 11 may be cut to a desired length 
so as to accommodate variations in room size in the event full size 
ceiling panel openings 15 cannot be accommodated at the edges of the room. 
In this manner, the ends of the cut-to-length main runners 9 and cross 
tees 11 rest on the upper surfaces of the mold cove strips 63, and thus 
the outer edges of ceiling system 1 are supported. Of course, the outer 
edges of these main members and cross tees may be positively secured to 
cove molding strips 63 by means of nails 46, as heretofore described in 
regard to FIGS. 3 and 5. 
In FIGS. 1 and 4, a cove board 65 is provided at the outer edges of ceiling 
1 such that the hook ends 37 of cross members 11 may be hooked thereto in 
the manner described above. 
Referring to FIG. 12, another variation of the wooden suspended ceiling 
system 1 of the present invention, as indicated in its entirety by 
reference character 1', may be utilized in which relatively wide, fluted 
solid wood beams 67 are substituted for main runners 9 heretofore 
described. Fluted beams 67 are essentially identical to main members 9, 
except that the width of the central portion 27' of the fluted beams is 
substantially wider than the central portion 27 of main runners 9. 
Additionally, the decorative recess 45', shown in the bottom face of the 
fluted beam, comprises four longitudinal, circular cross sectional grooves 
in place of the compound recess 45' provided in main members 45. It will 
be appreciated that the primary reason for using a wider fluted beam 47 in 
place of main runners 9 is that there will be a variation in width between 
the main runner fluted beams 47 and the width of cross tees 11 in ceiling 
system 1 thereby to give a different architectural or aesthetic appearance 
to the ceiling system 1' of the present invention. 
While the ceiling system shown herein illustrates the runners 9 and cross 
member 11 being perpendicular to one another and defining rectangular 
ceiling openings 15, those skilled in the art will recognize that the 
runners and the cross members can be at angles relative to one another 
other than perpendicular such that other shaped openings (i.e., traingular 
or other shapes) may be formed. 
In view of the above, it will be seen that the other objects of this 
invention are achieved and other advantageous results obtained. 
As various changes could be made in the above constructions or method 
without departing from the scope of the invention, it is intended that all 
matter contained in tne above description or shown in the accompanying 
drawing shall be interpreted as illustrative and not in a limiting sense.