Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2~239~
PATENT
1. PD-0282
MODULAR PANEL AND HINGE ASSEM~LY
~ACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a modular panel
and hinge assembly.
2. Description of Rel~ted Art
Hinge ~echaniq~s for connecting panel segments are
well known in the prior art. Elongated extruded hinge
mechanisms have also beën taught, for example, in U.S. ~ -
Patent No. 3,484,895, wherein a hinge ~echanism capable
of providing a 180-degree rotation is disclosed in the
form of drapery panelq. The hinge halves disclosed have
a cooperative bearing surface that permit~ one hinge
member to capture the end of another hinge member at a
fully extended position, and then, in turn, to be
captured by the other hinge member as it rotates to a
folded condition.
A hinge mechanism frequently represents the weakest
structural component in a panel system, yet it i3
critical that it performs its function throughout the
life of the structure.
There is a desire in the prior art to provide
improved moldèd hinge assemblies that can withstand
relatively rugged use and can protect the hinging
mechanism during the utilization of the panels.
~2~
PATENT
2. PD-0282
SUMMARY OF THE INv~NTION
The present invention relates to a modular panel
and hinge assembly that can be easily manufactured,
e.g., with extruded plastic components, and assembled
and that can relatively isolate the hinge asse~bly from
compressive forces in its intended applications.
According to an embodiment of the invention, a
plurality of modular panels are connectable, e.g.,
thro~gh A hinge assembly. The hinge assembly includes a
~0 first hinge member with a first stop surface, a second
stop urface, and an entrance opening in the first
member between the respective first and second stop
surfaces. One side of the opening is defined by a
cantilevered arm. A second link member is to be secured
within the opening and is movable relative to the first
hinge mem~er. One end of the link member extends into
the opening in the first hinge member and behind the
cantilevered arm. The ~econd link member includes a
third stop surface and a fourth stop surface on opposite
sides of the second link member that are respectively
complementary to ths first and second stop surfaces.
These respective stop surfaces define a pivotal movement
o~ the second link member about the opening a~ the
second link member moves within the opening. The second
link member lncludes first and second coupling ends
interconnected by an intermediate web member. The
coupling endsimay ha,ve a semicircular cross-sectional
hook configuration compatible with the opening
configuration in the first hinge member. A third hinge
member may also be attached to a coupling end on the
link member and may have corresponding stop surfaces, as
existed with regards to the first hinge member and the
second link member, to ~lso define ~ Qecond pivotal
movement of the second link member about an opening in
the third hinge member. The ~nterconnection of the
hinge members with the link member can be recessed from
a side surface of the pan~l members.
2~
PATENT
3. PD-0282
.
The first and third hinge members can also be
constructed to provide a configuration for interfacing
with a separate panel member, and can incorporate
bearing surfaces that will mini~ize any compressive
stress on the link member and its interfaces with the
first and third hinqe member~ when the panels are in
either a folded or an extended condition. Both the
first and third members can rotate 90 degrees about the
link member to permit a combined 180-degree rotation for
the hinge assembly.
The objects and features of the present invention,
which are believed to be novel, are set forth with
particularity in the appended claims. The present
invention, both as to its organization and manner of
operation, together with further objects and advantages,
may best be understood by reference to the following
description, taken in connection with the accompanying
drawings.
~8~
PAT~NT
4. PD-0282 :
~RIEF DESCRIPTION OF I~E~Fa~I~LGS
Figure 1 is a cros~-sectional view of a hinge
assembly;
Figure 2 is a partial exploded perspective view of
the hinge assembly;
Figure 3 is a cros~-~ectional partial view of the
hinge assembly with the panels extended in the same
plane;
~' Figure 4 is a partial cross-sectional view of the
hinge assembly with the panels being displaced;
Figure 5 is a partial cross-sectional view of t~e
hinge assembly with the panels in a folded
configuration;
Figure 6 is a per~pective view of the hinge
assembly in a garage door installation;
Figure 7 is a partlal front view of the garage door
embodiment;
: Figure 8 is a partial side view of the garage door
embodi~ent;
Figure 9 is a slde view of a second embodiment of
the hinge assembly;
Figure 10 is a perspective view of a retaining tab;
Figure 11 i8 a perspective view of multiple panel
configuration;
Figure 12 is an exploded perspective view of a
panel a~sembly according to the Flgure 11 embodiment.
Figure 13 is a partial exploded perspective view of
a hinge assembly according to the Figure 11 embodiment;
Figure 14 i~ a partial cross-sectional top view of
a hinge assembly ac~ording to the Figure 11 embodi~ent;
Figure 15 is a perspective view of a partially
folded multiple panel configuration according to the
Figure 11 embodiment;
Figure 16 i8 a top view of a folded multiple panel
configuration according to the Figure 11 embodiment;
PATENT
5. PD-0282
Figure 17 is a partial exploded perspective view of
a multiple configuration according to the Figure 11
embodiment;
Figure 18 is a partial cross-sectional view of a
multiple panel configuration according to the Figure 11
embodiment;
Figure 19 is a perspective view of a panel assembly
according to another embodiment of the invention; and
Figure 20 is a partial exploded perspective view of
frame portions of a panel assembly according to the
Figure 19 embodiment.
~; 2~2~
PATENT
6. PD-0282
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any
person skilled in the extrusion field to ~ake and use
the invention and sets forth the best modes contemplated
by the inventors for carrying out their invention.
Various modifications, however, will remain readily
apparent to those skilled in the art, since the generic
principles of the present invention have been defined
herein specifically to provide a relatively economical,
reliable, and rugged hinge assembly that can be used
with different forms of panel configurations.
Referring to Figures 1 and 2, examples of the hinge
assembly 2, 2' are disclosed and include a first hinge
member 4, 4', a second link member 6, 6', and a third
hinge member 8, 8'. Each of these hinge members can be
extruded from any thermal plastic synthetic polymer
composition material suitable for this application, such
as slightly plasticized polyvinyl chloxide, only
slightly plasticized polyvinyl acetate, and copolymers
of both of them, vinyl and the like. These members
could also be extruded out of metal such as aluminum
alloys.
As can be seen, the first and third hinge members 4
and 8, respectively, are preferably identical, to save
tooling and production costs, and are secured onto
coupling ends 10 and 12 of the link member 6. A web
portion 7 interconnects the coupling ends 10 and 12.
Each of the respective hinge members 4 and 8 have a
cross-sectional arcuate wall 13 defining a
cross-sectional arcuate cavity 14 extending from an
entrance opening and running along the length of each
extruded hinge member. Curvilinear surfaces define the
edges of the opening, with one surface being a concave
curvilinear surface 16, and the opposite surface being a
convex curvilinear surface 18. Complementary surfaces
are provided on the coupling ends 10 and 12 of the link
member 6. The link member 6 i8 relatively constant in
~2~
PATENT
7. PD-0282
cross-sectional thickness except for a tapered end
portion. One side of the arcuate opening 14 is formed
in the hinge members by a cantilevered arm that
terminates with a bulbous convex urface 18.
As shown in the embodiment of Figure 1, which is
particularly adaptable for conne~tion with a relatively
thick panel member, when the link member 6 pivots and
moves within the arcuate opening, respective stop
surfaces 20 and 22 on the exterior faces of hinge
members and corresponding stop surfaces 24 and 26 on
either side of the link member 6 define the extent of
pivotal movement to approximately 90 degrees. Stop
surfaces 24 and 26 are on the planar web portion 28 of
the link member 6. The coupling hook configuration of
the coupling ends 10 and 12 extend sufficiently into
respective arcuate openings.so that the link member 6 is
not released when stop surface 20 on the hinge member
contacts the stop surface 24 on the link member. The
convex curvilinear portion of the coupling link 6 that
is immediately adjacent to the convex bulbous portion 18
of the cantilevered arm can extend on either s~de of an
axis of rotation of the bulbous surface 18 in the
preferred embodiment.
The cross-sectional configuration of the coupling
ends 10 and 12 define a semicircular configuration of
roughly a C-shape. The coupling end i5 approximately
constant in its thickness across its length and comes to
a tapered point at the end. The cantilevered arm has an
approximately semispherical cross-sectional
configuration at its free end, with the remainder of the
cantilevered arm surfaces being parallel planar shapes.
As can be seen in Figures 3 through 5, the
individual hinge members and the link member are
preferably recessed from a side plane of the
corresponding panel sections 30 and 32 to assi~t in
protecting the hinge mechanism 2 from damage.
Additionally, the relative spatial positions of the
2 ~
PATENT
8. PD-02~2
hinge members 4 and 8 and the link member 6 permit
compressive bearing surfaces 34 and 36 on the end of the
respective panel sections 30 and 32 and compressive
bearing surfaces 38 and 40 on the sides of the
respective panel sections to transmit compressive forces
rather than transmitting these forces through the hinge
assembly 2.
In the embodiment of Figures 2 and 9, which are
applicable for relatively thin panels, the individual
hinqe members 4 and 8 can be extruded to include fingers
42 and 44 that can be connected to a panel sectlon,
e.g., by inserting an edge of a panel section between
the fingers 42 and 44. An inner wall portion 43 extends
from one finger 42 to the other finger 44 to limit the
extent to which a panel section can slide into the area
between finqers 42 and 44 and to define an open area 45
between the end wall 47 and the lnn~r wall portion 43.
The entire upper surface 46 can act as a bearing
surface, while the side bearing surfaces 48 and So can ~-
~ 20 support the weight of the folded hinge members to
; isolate the hinge assembly from compressive forces. The
principal design location of the compressive free
bearing surfaces on the hinge assembly is to spatially
position these surfaces to isolate the link member 6
from compresslve forces in either an extended or folded
position. An end cap or retainer member 52 (Figure 10),
that can have a perime~ter shape to match the shape of
the hinge member, can be friction fit within ~ slot 53
between the fingers 42 and 44 to close one end of the
hinge assembly, as seen in Figure 9. Dimples or ridges
could be molded to increase the friction fit. For
example, a single dimple (which is not in view in Figure
2 but is in view in Figures 9 and 10) may be formed on
the portion of retainer member 52 which fits into slot
53. The dimple 55 is convex, and extends outward on the
surface of member 52 which is not in view in Figure 2
(but is shown in Figures 9 and 10) so as to fictionally
PATENT
9. PD-0282
engage surface 57 of inner wall portion 43 upon retainer
member 52 being fitted into 810t 53. Alternatively, a
plug (not shown) of an arcuate configurat~on similar in
shape to the opening 14 can be bonded in each end of
each hinge member to prevent lateral movement of the
link member 6.
Since the link member 6 extends across the joint of
the respective hinge members 4 and 8 and along the
entire hinge assembly, light will not be transmitted
through the resulting panel assembly. Additionally, the
hinge members 4 and 8 and the link member 6 can have
subjectively designed exterior decorative surfaces to
provide a highly pleasing configuration from both sides
when the panel assemblies are extended.
In the embodiment shown in Figures 1 and 3 through
5, the panel member or segment can be formed with an
interior material such as a rigid foam or composite wood
54, with an exterior decorative skin surface material 56
such as a thin aluminum or plastic sheet. The skin
surface material 56 can terminate within a retention
cavity member 58 that is extruded on the other side of
the hinge assembly 2 on the support surface. The skin
surface material can be adhered to the panel material 54
and to the extruded hinge member with an appropriate
glue. Alternatively, the panel member can be extruded
as an integral continuation of the hinge member 2,
particularly if the panel member is relatively thin.
Referring to Figures 6-8, an embodiment of the
hlnge assembly can be advantageously used in a garage
door assembly having a plurality of panel sections with
the hinges of the present invention. An appropriate
hinge configuration is shown in cross-sectional views in
Figures 3 through 5. The interior of the panels can be
of a plastic foam, or even of an inexpensive wood
material, with an appropriate decorative and protective
outer skin 56. The respective end sections of each of
the panel seqments 60 can ~e capped with a rectangular
g~
PATENT
lo. PD-0282
. .
wood block member 62 that can respectively support
rollers 64 and capture the hinge acsembly to prohibit
lateral movement. A conventional foldlng hinge 63 can
interconnect the wood block members 62. The rollers 64
can be guided on respective guide rails or tubes 66 and
68 that can be placed on either side of the entrance
opening of the garaqe. While not ~hown, either a second
set of rollers or another set of guide rails will
restrain horizontal movement of the garage door. A
lo reversible ele~tric motor 67 can drive an axle 70
through a transmission belt drive mechan~sm 72.
Appropriate electronic garage door controls for remote
operation of the drive motor 67 are not shown. At
either end of the drive axle 70 are take-up pulleys 74
that can drive a wire cable 78 connected to the bottom
panel segment 60. The relative arrangement and angular
; inclination of the guide tubes 66 and 68 are such to
permit a gravity closing of the garage door. The garage
door may be held in opened, closed or partially opened
- 20 positions by any suitable door movement inhibiting
mechanisms, such as a dead bolt-l~ke structure (not
shown). Alternatively, the wire cable arrangement can
be mounted (not shown~ to provide both a positive
closing and a positive opening of the garage door.
Preferably, during the opening of the garage door, the
drive force is applied by the wire cable 78 to only the
bottom panel SQ that,the upper p`anels transmit the
bearing force of their collective weight through the
respective bearing surfaces of each hinge a~sembly,
rather than through the hinge assembly 2. Thus, when
the garage door is being opened, the respective hinge
assemblies are relatively free of stress forces and the
~;~ opening force is transmitted through each of the
respective bearing surfaces on each of the panel
members. Likewise, when the garage door is lowered, the
bearing surfaces, rather than the hinge member, again
support the weight of the garage door.
PATENT
11. PD-0282
Referring to Figure 11, a display panel system 90
can advantageously utilize the hinge assembly 2,
described above in either of the configurations shown in
Figures 2 and 9 or Figures 1 and 3 through 5 to connect
panel assemblies 92a-f. According to the Figure 11
embodiment, a display panel syste~ so includes multiple
(6 in Figure 11) rectangular panel assemblies 92a-f.
Each panel assembly 92a-f is provided with a panel
segment 96 and a frame assembly 94 (Figure 12).
Preferably, the panel segments 96 are formed from a
lightweight material such as a foam covered with a
decorative outer surface. It is highly desirable that
the display panel assembly 90 be portable so that it can
be transported to various trade shows and easily
assembled as a back drop for a display. Conversely, the
display panel should be easily disassembled in a similar
manner. Since there is a desire to make the display
panel 9o compact for s~orage or shipment, the respective
hinge assemblies 2 should alternate to permit the panel
members to rotate into the stacked configuration of
Figure 16. As can be readily appreciated, a pair of
display panels 92 can be mounted one on top of the
other, as shown in Figure 11, so that an upper set of
panels and a lower set of panels can be appropriately
connected to lncrease the height of the display panel
90, while permitting the portability of each of the
display panel sets~and to be one-half the size of the
erected display panel 90 for transportation purposes.
Appropriate connecting apparatus, as explained with
reference to Figures 17 and 18 can be utilized for
;~ securing the upper and lower panel sets.
A typical panel assembly 92 is shown in the
exploded view of Figure 12. Referring to Figure 12, the
panel assembly 92 includes a rectangular panel segment
96 surrounded on all four sides by a frame assembly 94.
The frame assembly 94 is composed of two horizontal
frame members 98 and 100, two vertical frame members 102
~,3~ ~
PATENT
12. PD-0282
and 104 and four L-shaped connectors 106, 108, 110 and
112. The terms horizontal and vertical are used only to
simplify the description of the illustrated embodiment.
It will be recognized, however, that elements described
as being horizontal may also be arranged in a vertical
or other orientation. Likewise, elements described as
being vertical may also be arranged in a horizontal or
other orientation.
The vertical members 102 and 104 have a
configuration similar to hinge members 4' and 8'
described above. The horizontal members 98' and 100 are
shaped similar to the vertical members 102 and 104 but
do not include the curvilinear surfaces 16 and 18 which
define the arcuate cavity 14 discussed above with
reference to Figures 1 and 2. Rather, the horizontal
members 98 and 100 are each provided with three planer
surfaces, e.g., 114, 116 and 118 shown with reference to
horizontal member 98.
Similar to the hinge members 4' and 8' described
above, the horizontal and vertical frame members 98,
100, 102 and 104 are each provided with fingers 42 and
44 (shown with reference to vertical member 102) that
can be connected to a panel section, such as panel 96.
Additionally, the fingers 42 and 44 of each horizontal
or vertical member define a slot 121 (in horizontal
members) and 123 (in vertical member~) in which a leg of
an L-shaped connector member can be inserted, as
discussed below.
Each L-Shaped connector member 106, 108, 110 and
112 includes a first leg portion 120, a second leg
portion 122 and an intermediate portion 124 connecting
the first and second leg portions (shown with reference
to L-~haped connector member 106). As shown in Figures
12 and 18, one leg portion, e.g., leg portion 120, is
inserted in a slot 121 defined by the finqers of a
horizontal member, e.g., horizontal member 98. The
other leg portion, e.g., leq portion 122 of connector
t~
PATENT
13. PD-0282
106, is inserted in a slot 123 defined by the fingers of
a vertical frame member, e.g., frame member 102. In
order to provide a tighter fit, each leg portion 120 and
122 of each connector member 106, 108, 110 and 112 may
be provided with dimples or ridges, such as dimples 125
and 127, respectively provided on leg port~ons 120 and
122. Dimple 125 provides a convex, ralsed surface which
frictionally engages surface 129 of inner wall portion
131 of a horizon~al member, such as horizontal member
98, when leg portion :L20 ~s inserted in slot 121.
Similarly, dimple 127 provides a convex, raised surface
which frictionally engages surface 57 of inner wall 43
of a vertical member, such as vertical member 102, when
leg portion 122 is inserted in slot 123. In this
lS manner, the horizontal frame members 98 and 100 may be
securely connected with the vertical frame members 102
and 104 by the connector members 106, 108, 110 and 112,
while the panel segment 96 is arranged between the
fingers of each of the horizontal and vertical frame
members.
Referring to Figures 13 and 14, two panel
assemblies 92a and 92b of Figure 11 are connected by the
hinge arrangement formed by two vertical frame members
102 and 103 and a link member 105 in a manner similar to
the connection of hinge members 4' and 8' and link
member 6' described above with reference to Figure 2.
As a result, the'panel assemblies 92a and 92b are
pivotally connected with each other and can pivot
relative to each other in a manner similar to the
pivotal movement discussed above with reference to
Figure 1 and 2.
Referring to Figure 14, three panel assemblies,
92a, s2b and 92c of Figure 11 are shown as being
pivotallv connected in a manner similar to that -~
;~ 35 descr~bed above. However, the hinge or pivot connection -~
between the panels 92a and 92b allows pivotal motion in
the direction opposite to the hinge or pivot connection
PATENT
14. PD-0282
between panels 92b and 92c. In this manner, the three
panels 92a, 92b and 92c allow pivotal movements to
positions as shown in Figures 15 and 16.
Figure 11 shows a six panel configuration having
three upper panels and three lower panels, the three
upper panels being connected to each other in the manner
shown in Figure 14 and the three lower panels being
connected with each other in the manner shown in Figure
14 and also being connected to the upper panels in a ~-
manner as discussed below. This arrangement allows the
six panel configuration to form an S or Z bend, as shown
in Figure 15. This arrangement also allows the
configuration to fold, as shown in Figure 16, such that
each panel is arranged parallel to the other panels. As
a result, a high degree of freedom of selection of the
; appropriate folding, unfolding or partially folding
~ state iB provided. It is noted that the folded state
-~ shown in Figure 16 is ideal for storage or shipping of
an assemble panel configuration. ~ --
Figures 17 and 18 illustrate stacking or otherwise -~
connecting panel assemblies in a non-pivoting manner. `~
Referring to Figure 17, panel assemblies 92a and 92b are
shown as being pivotally connected in a manner as
described above with reference to Figure 13. Figure 17
also shows panel 92d being connected to panel 92a in a
non-pivoting manner.
As shown in,Figure 17, a straight connecting member
148 is inserted in a slot 150 defined between the
curvilinear surfaces portion and the fingers of the
vertical frame members. The straight connector 148
extends partially into such slot formed in a vertical
frame member of the panel assembly 144 and extends
partially into such slot formed in a vertical frame
member of the panel assembly 146 to, thereby, connect
the panel assembly 144 and the panel assembly 146
together. Each straight connector 148 may be provided
with dimples or ridges to enhance the frictional contact
``:
PATENT
15. PD-0282
with surface 59 of wall 13 of a vertical frame member.
In the embodiment shown in Figures 17 and 18, a dimple
151 is provided adjacent one end of straight connector
member 148 and presents a convex raised surface for
frictionally engaging surface 59 of cross-sectional
arcuate wall 13 when straight connector member 148 is
inserted in slot 150. As shown in Figure 17, straight
connector member 148 does not have a dimple for
enhancing the frictional fit with a vertical frame
member of an upper panel assembly (e.g., panel assembly
92d). Rather, the upper panel assembly can be securely
held by straight connector member 148 and by gravity.
However, other embodiments may include a dimple or ridge
near both ends of straight connector member 148.
Figure 18 shows a cross-sectional view of the panel
connections shown in Figure 17. Dimples 125, 127 and
151 are exa~gerated in Figure 18 so as to more clearly
show these dimples in the Figure.
Figure 19 shows an embodiment of a panel assembly
wherein three panel portions 150, 152 and 154 are
enclosed within a frame assembly comprising two vertical
frame members 156 and 158 and six horizontal frame
members 160, 162, 164, 168, 170 and 172. It will be
recognized that panel assemblles having other
configurations of panel members and horizontal and
vertical frame members can be designed within the scope
of the present invention. The connection between the
vertical members 156 and 158 and the horizontal members
160 and 172 is similar to the connection between
vertical and horizontal members described above, e.g.,
with reference to Figure 12. However, horizontal
-~; members 162, 164, 168 and 170 each connect to vertical
members 156 and 158 along the length of the vertical
~; members, at a lo~ation between the two ends of the
-~ 35 vertical members.
As shown in Figure 20, an L-shaped connector member
174 (similar to member 106 discussed above) has a first
-
- ~2~
PATENT
16. PD-0282
leg portion 176 which is inserted in a slot formed
between finger members of vertical member 156. A second
leg 178 extends out from and substantially perpendicular
to the vertical frame member 156. The leg portion 176
and the leg portion 178 are connected by an intermediate
portion 180 of the L-shaped connector member 174. The
intermediate portion 180 has a smaller width than the
width of each leg portion 176 and 178 of the L-shaped
connector member 174. Also, the vertical frame member
156 is provided with an open gap 182 between the finger
members to allow intermediate portion 180 to extend
therethrough.
Leg 178 of L-shaped connector member 174 fits into
a slot provided between the fingers of horizontal member ;.~.
162 in a manner as discussed above with regard to L-
shaped connector 106. Similar to L-shaped connector 106
discussed above, each leg of L-shaped connector 174 can
~: be provided with a dimple or ridges to enhance the :
; frictional fit with the horizontal and vertical frame
members. For example, leg 178 of L-shaped connector 174
has a dimple 179 which presents a convex, raised surf-ace
: for engaging surface 163 of inner wall portion 165 of
horizontal frame member 162 (note that a concave surface
of dimple 179 is shown in view in Figure 19, the convex,
raised surface of dimple 179 ls hidden from view in
Figure 19).
As is apparent from~Figure 19, horizontal members
can be connected to vertical members at any location
along the length of the vertical members as well as at
the ends of the vertical members. The above discus~ed
:~ panel and hinge assembly, therefore, allows substantial
~: freedom in design and assembly of panel and hinge
:~ configurations to accommodate a variety of needs and
applications.
:~ 35 It will be recognized that the above-described
embodiments of panel assemblies, connector members and
panel configurations can be constructed in various
:
.'-.
~2(~g6 ~ ~
.
PATENT
17. PD-0282
manners to accommodate various needs. The freedom of
assembly and pivotal connections allow a high degree of
design freedom to, thereby, allow a user to freely
design and construct multiple panel configurations to
accommodate various needs. For example, a panel
configuration can be constructed to provide an ideal
multiple panel display system and/or a multiple panel
exhibit system for a trade-show, convention or the like.
Embodiments of the above described panel and hinge
assemblies can be used as a multiple panel closure for,
e.g., a roll-top desk, a garage door, a movable window
covering such as for a kiosk window, or the like.
Additionally, a multiple panel configuration can be
constructed to provide a movable and foldable wall or
room partition. Many multiple panel configurations can
be designed so as to readily fold into a relatively
compact form, such as shown in Figure 16, for easy
storage or shipping. Moreover, components of the panel
assemblies can be readily manufactured using relatively
inexpensive plastic extrusion techniques, providing very
cost effective panel assemblies. Other features and
- advantages of various embodiments of the invention are
evident from the above disclosure.
Those skillQd in the art will appreciate that
various adaptations and modifications of the ~ust-
described preferred embodiment can be configured without
departing from tbe scope and spirit of the invention. ~
Therefore, it is to be understood that, within the scope ~ ;
of the appended claims, the invention may be practiced
other than as spècifically described herein.