U.S. patent application number 12/031877 was filed with the patent office on 2009-08-20 for composite floor systems and apparatus for supporting a concrete floor.
This patent application is currently assigned to Lightweight Structures, LLC (a Wisconsin limited liability company). Invention is credited to JAMES F. JENDUSA.
Application Number | 20090205285 12/031877 |
Document ID | / |
Family ID | 40953817 |
Filed Date | 2009-08-20 |
United States Patent
Application |
20090205285 |
Kind Code |
A1 |
JENDUSA; JAMES F. |
August 20, 2009 |
COMPOSITE FLOOR SYSTEMS AND APPARATUS FOR SUPPORTING A CONCRETE
FLOOR
Abstract
An apparatus for supporting a concrete floor and a composite
floor system constructed therewith comprises form panels supported
between a plurality of joists, the joists including a shear
connector at least partially embedded in the concrete slab of the
floor system. Each of the joists may be formed of a double channel
structural member, including a top chord to which the shear
connector is secured, a bottom chord and a reinforced web.
Inventors: |
JENDUSA; JAMES F.;
(Oconomowoc, WI) |
Correspondence
Address: |
GODFREY & KAHN S.C.
780 NORTH WATER STREET
MILWAUKEE
WI
53202
US
|
Assignee: |
Lightweight Structures, LLC (a
Wisconsin limited liability company)
Hartland
WI
|
Family ID: |
40953817 |
Appl. No.: |
12/031877 |
Filed: |
February 15, 2008 |
Current U.S.
Class: |
52/650.3 ;
52/656.9; 52/741.1; 52/846 |
Current CPC
Class: |
E04B 5/29 20130101; E04C
3/08 20130101; E04B 5/263 20130101 |
Class at
Publication: |
52/650.3 ;
52/846; 52/656.9; 52/741.1 |
International
Class: |
E04B 5/36 20060101
E04B005/36; E04C 3/04 20060101 E04C003/04; E04B 1/04 20060101
E04B001/04; E04C 5/16 20060101 E04C005/16 |
Claims
1. An apparatus for supporting a concrete floor comprising: a
plurality of joist assemblies, each joist assembly having a top and
a bottom and comprising a first frame member having a first top
flange, a first web portion and a first bottom flange, a second
frame member having a second top flange, a second web portion and a
second bottom flange, the second frame member arranged such that
the second web portion contiguously contacts the first web portion;
a plurality of continuous shear connectors, each shear connector
having a vertical portion with a bottom secured to the top of one
of the plurality of joist assemblies, the vertical portion having a
length and a top with an arcuate end; and a plurality of panels,
each panel supported between a pair of adjacent joist assemblies of
the plurality of joist assemblies.
2. The apparatus of claim 1, wherein the web portions of each of
the first and second frame members of each of the joist assembly
include a support mechanism for supporting one of the panels
between a pair of adjacent joist assemblies of the plurality of
joist assemblies.
3. The apparatus of claim 2, wherein the support mechanism
comprises an angle component extending outwardly from the web
portions of each of the first and second frame members.
4. The apparatus of claim 3, wherein the support mechanism further
comprises a set of clips and tabs formed within the web portions of
each of the first and second frame members, each tab vertically
aligned with one of the clips for supporting the angle
component.
5. The apparatus of claim 1, wherein the first and second web
portions of each of the first and second frame members further
include a plurality of openings formed for accommodating building
utilities.
6. The apparatus of claim 1, wherein the joist assemblies and the
shear connectors are constructed of steel.
7. The apparatus of claim 1, wherein the panel is constructed of a
foam material.
8. An apparatus for supporting a concrete floor comprising: a least
one pair of joist assemblies, each joist assembly having a top
chord, a bottom chord and a web portion therebetween; a least one
pair of continuous shear connectors, each shear connector having a
bottom secured to the top chord of the joist assembly, a top having
an arcuate shape and a vertical portion extending therebetween, the
vertical portion including a plurality of openings formed therein;
and at least one panel supported between adjacent joist
assemblies.
9. The apparatus of claim 8, wherein the web portion of each joist
assembly comprises a plurality of apertures formed therein.
10. The apparatus of claim 8, wherein the web portion of each joist
assembly has first and second surfaces and wherein each of the
first and second surfaces includes a support mechanism, wherein the
support mechanisms on adjacent joist assemblies are configured to
support the at least one panel therebetween.
11. The apparatus of claim 8, wherein each joist assembly comprises
a first frame member having a first top flange, a first web portion
and a first bottom flange, a second frame member having a second
top flange, a second web portion and a second bottom flange, the
second frame member arranged such that the second web portion
contiguously contacts the first web portion.
12. The apparatus of claim 11, wherein the bottom of each shear
connector comprises a plurality of horizontal attachment portions,
at least one of the horizontal attachment portions configured to
secure to the first top flange of the first frame member and at
least one other of the horizontal attachment portions configured to
secure to the second top flange of the second frame member.
13. The apparatus of claim 8, wherein the joist assemblies and the
shear connectors are constructed of steel and the panel is
constructed of at least one layer of foam material.
14. A method of supporting a concrete floor comprising: providing a
pair of adjacent joist assemblies, each joist assembly having a top
chord, a bottom chord and a web portion therebetween; providing
each joist assembly with a continuous shear connector having an
arcuate top portion adapted to be embedded in the concrete floor, a
vertically extending middle portion including a plurality of
apertures formed therein and a bottom portion; securing the bottom
portion of the continuous shear connector to the top chord of each
joist assembly; and permanently securing a panel between the
adjacent joist assemblies.
15. A composite floor comprising: two or more joist assemblies; one
or more shear connectors secured to one or more of the joist
assemblies, each shear connector having a bottom portion, a
vertically extending middle portion including a plurality of
apertures formed therein, an a top portion having an arcuate shape;
one or more panels supported between the joist assemblies, wherein
the panels are permanently secured between the joist assemblies; a
concrete layer poured over the panels to a height above the shear
connector such that middle portion and top portion of shear
connector are embedded in the concrete layer when the concrete
layer cures.
16. A shear connector adapted for securing to a joist and embedding
in a concrete layer poured over panels connected to a plurality of
joists to form a composite floor, the shear connector comprising: a
bottom portion secured to the joist; a top portion having an
arcuate shape, the top portion adapted to be embedded in the
concrete layer; and a middle portion extending between the bottom
portion and the top portion, the middle portion including a
plurality of openings formed therein and adapted to be embedded in
the concrete layer.
Description
BACKGROUND
[0001] The present invention relates generally to building
components and more particularly to an apparatus for supporting a
concrete floor and composite floor systems constructed
therewith.
[0002] Many commercial buildings and some larger, multi-story
residential complexes, such as apartment buildings or condominiums,
utilize concrete floor decking or concrete floors in their
construction. Concrete floor decking has also become increasingly
popular in residential and smaller constructions over the last
decade. Concrete floor support systems have several advantages over
traditional decking materials, such as strength, rigidity,
durability, mold resistance, sound attenuation, suitability for
in-floor radiant heating and the availability of decorative
concrete finishes.
[0003] Traditional concrete flooring systems were adapted from
commercial construction, and generally constructed by spanning
steel or wood joists between structural walls or primary structural
members, spacing or bridging the joists with rebar or blocking
members to provide lateral support to the joists, and laying
plywood, steel, aluminum, or fiberglass decking on or between the
joists and pouring a thick concrete layer over the decking. The
resulting flooring systems are heavy and require significant time
to install. Further, in order to bear the additional weight of the
decking and concrete layer during curing, the decking panels must
be shored (or braced), adding to the cost of the systems. In
smaller constructions, such as residential applications, these
traditional systems were generally too expensive and logistically
challenging to install.
[0004] Further, in application, conventional concrete flooring
systems are subject to significant horizontal and vertical forces,
and in particular, horizontal shear occurring along the
longitudinal top of primary and secondary joist members. Indeed,
these systems ultimately fail because of loss of interfacial force
in the shear span.
[0005] Composite concrete floor support systems offer a solution to
traditional concrete floor systems. Composite systems utilize steel
joists having a top chord or portion that is embedded into the
poured concrete deck. The top chord then forms a shear connector to
prevent slippage from occurring between the concrete slab and the
joist, due to horizontal shear along the joist, which can reduce
the amount of reinforcement required over the traditional
systems.
[0006] Various forms of shear connectors have been developed,
including elongated studs welded to the top chord of the joist
member. The studs are embedded in the concrete, thereby
transferring horizontal shear forces from the slab to the beam.
However, these studs are welded to the joist after the joist has
been connected to the structure during erection, requiring
significant labor and time, and they can be hazardous to crew
members after installation, but before the concrete has been
poured. Other types of shear connectors include, joists having an
irregular or S-shaped tap chord, such as the Hambro.TM. joist, or
alternatively, a shear connector of the type disclosed in U.S. Pat.
No. 7,013,613 to Boellner et al., which teaches an extended length
shear connector including protrusions and indentations on the
surface thereof
[0007] Regardless of the shear connector used in the prior art
systems described above, these systems still require reinforcement
of the concrete layer. In particular, rebar (reinforcing bar),
metal mesh, decking or cross braces are placed over or in between
the joists to reinforce the concrete layer before the concrete is
poured. Accordingly, this type of composite system, while having
increased strength over non-composite systems, can be heavy and
expensive due to the added cost of reinforcement material. However,
rebar and other metal reinforcements are subject to corrosion and
deterioration of the floor. Further, in systems where the
reinforcement is positioned on top of the top chord or shear
connector, these systems are subject to failure due to tearing of
the deck near the shear connector.
[0008] In addition, many of the prior art systems require removable
framing systems to be in place before construction and removed
after the concrete has cured, adding to the cost of installation of
these types of composite systems.
[0009] Accordingly, there is a need for a lighter floor support
system for use with concrete floor decking, in particular, for use
in above-grade and residential constructions, while also offering
decreased costs and ease of installation on-site.
SUMMARY
[0010] A composite flooring system and method for supporting a
concrete flooring system in accordance with one embodiment of the
present invention can be used in situations where conventional
wood, masonry, or light gauge steel framing materials are used. The
system includes a plurality of joist assemblies having a shear
connector secured thereto, the joist assemblies arranged in a
spaced apart and substantially parallel configuration, with a panel
supported between each pair of adjacent joist assemblies, and a
concrete layer provided over the panel and shear connector
components.
[0011] The joist assembly includes a first frame member having a
top flange, a web portion and a bottom flange and a second frame
member of mirror image construction. The frame members are arranged
in a back-to-back fashion, providing the joist assembly with a two
layered and reinforced web portion. The web portions of each of the
frame members include a plurality of space-apart clips and tabs
which can secure a support angle in place on the web portion of the
frame member along the length thereof for supporting sections of
polystyrene foam in between the frame members. The web portions of
each of the frame members can also include openings to permit
plumbing, electrical wiring, ductwork or other building utilities
to run through the support system.
[0012] A shear connector is secured to the top chord of each joist
assembly and extends the entire length thereof The shear connector
extends vertically upwards from the top chord of the joist, having
an arcuate end or bend. This bend provides additional surface area
to which the concrete layer may bond and can be used to stiffen the
shear connector. The shear connector also includes a plurality of
openings that also provide additional surface area of contact
between the shear connector and the concrete layer, further
strengthening the resulting steel-concrete composite flooring
system. The shear connector can include attachment portions
including downwardly extending tabs for engaging slots provided in
the top chord of the joist assembly. By providing a shear connector
with attachment tabs and a top chord with corresponding attachment
slots, the time it takes to assemble the joist and shear connector
members is minimized.
[0013] The system may also include a method for supporting a
concrete floor by providing at least two joist assemblies, as
described above, and each having a shear connector secured to the
top chord thereof, and permanently securing at least one foam panel
between a pair of adjacent joist assemblies. The method can include
forming a composite floor of the present invention by additionally
pouring a layer of concrete over the foam panel and to a height
above the top of the shear connector.
[0014] The composite floor system and methods for supporting a
concrete floor eliminate the need for reinforcement provided within
the concrete layer, such as rebar, metal mesh or cross braces, thus
rendering the system lighter, easier to install and less expensive.
In addition, without the necessity to reinforce the concrete, the
concrete layer is more suitable for installation of radiant heating
systems. Furthermore, construction processes are simplified because
cross blocking, special tools and skills required for framing the
system during the curing period are not require due to the reduced
weight of the system, and the drilling and cutting associated with
traditional wood products are all unnecessary. Further, the system
provides a composite concrete floor that does not require framing
material to be removed, significantly shortening set up and
construction time.
[0015] The composite concrete floor support systems disclosed
herein have all the advantages of concrete flooring system, such as
strength, rigidity, durability, mold resistance and sound
attenuation, with the added benefit of utilizing a foam insulation
layer to provide a durable and energy-efficient construction.
Because of benefits, such as sound attenuation, impact resistance,
and high R-value, the foam layer enhances the advantages of the
concrete decking to provide a lighter, more durable composite
system over traditional composite concrete flooring systems.
[0016] Various other features, objects, and advantages of the
invention will be made apparent to those skilled in the art from
the accompanying drawings and detailed description thereof
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of a composite floor system of
the present invention, with a concrete layer shown in shadow;
[0018] FIG. 2 is a partial perspective view of a joist assembly for
use in the composite floor system illustrated in FIG. 1;
[0019] FIG. 3 is a partial side view of a channel member used in
constructing the joist assembly illustrated in FIG. 2;
[0020] FIG. 4 is a sectional view of the channel member illustrated
in FIG. 3, taken along the line 4;
[0021] FIG. 5 is a partial side view of a shear connector used in
the composite floor system illustrated in FIGS. 1 and 2;
[0022] FIG. 6 is a sectional view of the shear connector
illustrated in FIG. 5, taken along the line 5;
[0023] FIG. 7 is an end view of a support angle used in
constructing the joist assembly illustrated in FIG. 2;
[0024] FIG. 8 is a partial side view of a forming panel used in the
composite floor system illustrated in FIGS. 1 and 2;
[0025] FIG. 9 is an exploded side view of the composite floor
system illustrated in FIGS. 1 and 2, illustrating construction of
the joist assembly and panel components; and
[0026] FIG. 10 is a side view of the composite floor system
illustrated in FIGS. 1, 2 and 9, illustrating the joist assembly
and foam panel components, and including a layer of concrete,
completing the composite floor system.
[0027] FIG. 11 is a partial perspective view of an alternative
embodiment of a joist assembly for use in a composite floor system
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIGS. 1 through 10 illustrate one embodiment of a system 30
for supporting a concrete deck or concrete floor in accordance with
the present invention. In its simplest form, the floor support
system 30 includes at least one panel 32, supported between at
least one pair of joist members or assemblies, indicated generally
at 34, and a concrete layer 35. As will be readily apparent from
the following description, the floor support system is not limited
to any particular construction application and can be utilized in
grade level or above-grade projects, and in both small and large
flooring and/or roofing projects. In addition, the floor support
system 30 is compatible with a number of different shoes, hangers
and/or connectors, ensuring the system is properly secured to
primary structural members such as walls, primary girders, beams,
trusses or foundation members, as will be recognized by those
skilled in the art.
[0029] Turning first to FIGS. 1-4, each joist assembly 34 comprises
first and second C-shaped channel or frame members 36 and 38,
respectively, of mirror image construction, arranged in a
back-to-back fashion. The channel member 36 includes a top flange
40, a bottom flange 42 and a web portion 44 therebetween. Likewise,
the channel member 38 includes a top flange 46, a bottom flange 48
and a web portion 50. The channel members are preferably
constructed of steel, but other metals, alloys, composite materials
or any material of sufficient strength as determined by required
engineering standards may be used to form the channel members 36
and 38.
[0030] The web portion 44 of the channel member 36 includes a
plurality of clips 52 and corresponding tabs 56. The clips 52 are
located near the top of the web portion 44 and are spaced apart
along the length 47 of the channel member 36. As best illustrated
in FIG. 3, each of the tabs 56 is vertically aligned with one of
the clips 52 for retaining a support angle 59 (shown in FIGS. 7, 9
and 10). The clips 52 and tabs 56 can be stamped or punched within
the web portion 44, leaving an aperture within the web, or
alternatively, the clips and the tabs can be secured to or
otherwise provided within the web portion.
[0031] The support angle 59 includes a leg 66 that is inserted into
the clips 52 and a leg 68 that rests on the tabs 56, securing the
support angle 59 along the length of the channel 36. The legs 66
and 68 may further be secured to the channel member 36 by welding
or using screws, rivets, pins or another fastener that secures the
support angle in place.
[0032] Similarly, the web portion 50 of the channel member 38
includes a plurality of clips 54 and corresponding tabs 58. The
clips 54 are located near the top of the web portion 50 and are
spaced apart along the length 49 of the channel member 38. Each of
the tabs 58 is vertically aligned with one of the clips 54 for
retaining a support angle 61 (shown in FIGS. 7, 9 and 10). The
clips 54 and tabs 58 can be stamped or punched within the web
portion 50, leaving an aperture within the web, or alternatively,
the clips and the tabs can be secured to or otherwise provided
within the web portion.
[0033] The support angle 61 includes a leg 70 that is inserted into
the clips 54 and a leg 72 that rests on the tabs 58, securing the
support angle 61 along the length of the channel 38. The legs 70
and 72 may further be secured to the channel member 38 by welding
or using screws, rivets, pins or another fastener that secures the
support angle in place.
[0034] It will be appreciated by those skilled in the art that the
clips and tabs provided within the web portions of each of the
channel members may be replaced by another support mechanism that
adequately retains the support angles in place. Such a mechanism
can include using screws, rivets, pins or alternatively by welding
the support angle to the channel members.
[0035] The web portions 44 and 50 of each of the channel members 36
and 38 also include a plurality of apertures 60 and 62,
respectively, to permit plumbing, electrical wiring, ductwork or
other building utilities to run through the support system. As will
be recognized by those skilled in the art, the size of the channel
members 36 and 38, including but not limited to, the span of their
corresponding web portions 44 and 50, the number of clips 52 and
tabs 56 provided, and the size and number of apertures 60 and 62
provided within the web portions 44 and 50, will depend on the
given construction application, and is determined by, among other
factors, the span of the flooring system to be installed, loading
considerations of the floor, use and location of the building and
applicable ANSI, ASTM, and/or governmental design and safety
standards.
[0036] As best illustrated in FIGS. 2, 9 and 10, the joist assembly
34 is formed by arranging the channel members in a back-to-back
fashion. The top flange 40 of the channel member 36 is horizontally
aligned with the top flange 46 of the channel member 38, forming
top chord 80 of the joist assembly 34. The bottom flange 42 of the
channel member 36 is horizontally aligned with the bottom flange 48
of the channel member 38, forming bottom chord 82 of the joist
assembly 34. As illustrated in the Figures, in this arrangement,
the web portions 44 and 50 of the channel members are aligned and
apertures 60 and 62 along the length of each of the channel members
are also aligned.
[0037] It will be appreciated from FIG. 10, that the joist assembly
34 includes a two-layered or reinforced web comprising both the web
portions 44 and 50. Once positioned in this manner, the channel
members 36 and 38 can be secured together, if required, by welding
or using bracket, screws, clips, rivets, pins or another
fastener.
[0038] As best shown in FIGS. 1, 2, 9 and 10, a shear connector 84,
is secured to the top chord 80 of each of the joist assemblies 34.
The shear connector 84 is preferably constructed of steel or
another material capable forming a sufficient bond with the
concrete layer 35, resulting in the required composite
action/strength. As best illustrated in FIG. 6, the shear connector
84 extends the entire length of each of the joist assemblies, and
has a substantially vertical portion, indicated generally at 90,
and a plurality of attachment portions, indicated generally at 86
and 88, extending horizontally away from the bottom 92 of the
vertical portion 90.
[0039] The attachment portions 86 and 88 are short, substantially
planar members formed on alternating sides of the vertical portion
90. Each of the attachment portions 84 and 86 includes downwardly
extending tabs 94 and 96, respectively, for engaging the top chord
80 of the joist assembly 34. In particular, the top chord 80 is
provided with a plurality of spaced apart slots 102 and 104 (shown
in FIG. 9) for receiving the tabs 94 and 96, respectively, on each
of the alternating attachment portions 84 and 86. Once positioned
in this manner, the tabs 94 and 96 may be secured within the slots
102 and 104, if required, by using adhesives or welds, or using
fasteners, such as screws, clips, rivets or pins. Although the
attachment portions 84 and 86 are illustrated having two tabs on
each segment, it will be recognized that more than two tabs may be
provided, and a corresponding number of slots will be provided
within the top chord 80 of the joist assembly 34.
[0040] The vertical portion 90 of the shear connector 84 includes
an arcuate end or bend 110 located at the top thereof This bend 110
can be used to stiffen the vertical portion 90 of the shear
connector and also provides additional surface area to which the
concrete layer 35 may bond. The bend 110 can be formed in either
direction, as is not limited to the direction indicated in FIG. 6.
Consistent with the broader aspects of the present invention, the
bend 110 can be replaced with another extension or protuberance
that provides at least the same amount of contact surface area for
bonding with the concrete layer 35. In addition, the vertical
portion 90 also includes a plurality of openings 100 formed along
the length 98 of the shear connector 84. These openings also
provide additional surface area of contact between the shear
connector 84 and the concrete, further strengthening the resulting
steel-concrete composite flooring system.
[0041] Turning now to FIG. 8, and with reference to FIGS. 1, 9 and
10, each panel 32 is a substantially planer member, having top and
bottom surfaces 112 and 114, respectively, a thickness 115 and
opposing ends 116 and 118. The ends of each of the panels 32 are
configured to be supported by the support angles 61 and 59 between
two adjacent joist assemblies 34, as best illustrated in FIG. 1.
Preferably, each end 116 and 118 is provided with a notch or groove
120 and 122, respectively, for receiving at least a portion of each
of the adjacent support angles 61 and 59. The panel 32 is
preferably constructed of polystyrene or polyisocyanurate
insulation foam, however, plywood, oriented strand board or
particle board may also be used. The size of the panels 32,
including the length, thickness 115 and span 117 is determined by
spacing of the joist assemblies 34, the material of panel 32 and
applicable design standards, as recited herein.
[0042] An alternative embodiment of the present invention is shown
in FIG. 11. In this embodiment, stiffeners 130 are incorporated at
the ends of a joist 34. The stiffeners 130 extend in a vertical
direction between the top 80 and bottom 82 chords of the joists 34,
and the legs of the stiffeners 130 may be bolted or otherwise
secured to the joists 34. The stiffeners 130 provide increased
stiffness an reinforcement at the ends of the joists 34.
[0043] As illustrated in FIGS. 8-9, and also in FIGS. 1 and 10, the
composite flooring system 30 of the present invention is
constructed by providing at least two joist assemblies 34, each
having a shear connector 84 secured to the top chord 80 thereof,
and securing the panel 32 between the joist assemblies by inserting
the leg 68 of the support angle 59 into the groove 122 on the end
118 of the panel 32, and by inserting the leg 72 of the support
angle 61 into the groove 120 on the end 116 of an adjacent panel
32. The panels 32 may be additionally secured to each joist member
using an adhesive, such as epoxy or a polymeric adhesive,
sufficient to securely bond the panel 32 to the joist assembly
34.
[0044] The concrete layer 35 is poured on top of the panels 32, to
a height above the bend 110 in the shear connector 84. The panels
32 remain in place after the concrete layer cured. The amount of
concrete utilized, and therefore the height of the concrete layer
is determined, at least in part, by the particular type of concrete
utilized, the particular construction application, the ultimate
live and dead loads, including the weight of additional flooring,
the size of the joist assemblies utilized, and the type of panel
selected. It will be appreciated that materials other than
concrete, such as concrete-fiberglass composites, or treated
concrete materials can be used for the layer 35.
[0045] It can be seen that the composite floor system 30 and
methods of the present invention provides a lighter and compact
composite floor support system compared to conventional composite
systems by eliminating the need for concrete reinforcement. By
including foam panels 32 that remain in place after construction of
the system, in combination with a joist assembly 34 that includes a
reinforced web portion (the web portions 44 and 50 of the channel
members) and a shear connector 84 provided with a plurality of
openings 100 to increase the surface area for contact with the
concrete layer, the composite system of the present invention does
not require use of rebar or other concrete reinforcements. Without
regard to any particular theory or mode of installation, the
present invention provides a composite system 30 that utilizes a
novel construction, allowing the concrete 35 and foam panels 32 to
act as a compression flange, distributing horizontal shear forces
from the slab to the primary structural members. As such, by
eliminating the need for concrete reinforcement, the present
invention can provide a less expensive and easier to assemble
system.
[0046] While the invention has been described with reference to
preferred embodiments, those skilled in the art will appreciate
that certain substitutions, alterations and omissions may be made
to the embodiments without departing from the spirit of the
invention. Accordingly, the foregoing description is meant to be
exemplary only, and should not limit the scope of the invention as
set forth in the following claims.
* * * * *