Note: Descriptions are shown in the official language in which they were submitted.
~756~3~
COMPOSITE PANEL FOR
HOUSEBUILDING AND OTHER PURPOSES, AND
A FLOOR CONSTRUCT~ON MADE FROM SUCH PANELS --
This lnvention pertains to panel structures, and
more specifically to a composite panel of both rigid
and elastic materials notable for its soundproofing
and shock absorbing properties and suitable for use
in housebuilding and like installations. The invention
also speciflcally deals with a floor construction made
by use of such composite panels~
A variety of panel products have been suggested
and used for sound absorbing and insulating applications,
as in flooring, subflooring, wall facings, ceilings,
partitions, and doors. The most typical of such known
panel products, and the most pertinent to the instant
invention, are those having glass wool, rock wool or
like sound absorbing material packed between a pair of
rigid facings. A drawback of these conventional structures
manifests itsel~ when they are installed upstandingly.
Being loosely packed between the facings, the sound
absorbing materials tend to settle down under their own
weight, thus rendering the sound absorbing or insulating
abilities of the panels unsatisfactory.
The above drawback has heretofore been circum-
vented by providing several partitions across the facings
and by filling each partitioned space with a sound
~7S636~
absorbing material. This remedy has given rise to
several difficulties, however. The panels with such
interfacing partitions are difficult to manufacture,
not suitabl~ for mass production in the form of
standardized units, and so very costly. Further the
partitions, being of material subject to aging, present
a cause for the warpage of the facings with the pass-
age of time.
The soundproofing capacity of the prior art
composite panels have also been poor. When used for
the flooring or subflooring of the second or higher
stories of houses, for example, the known panels have
been quite unable to insulate noises such as loud voices,
and shocks such as those due to heavy objects dropped
on the floor, from the lower stories.
One conventional measure for improving the vibra-
tion damping capacity of floors has been to cushion such
understructure members as joists and sleepers. The
cushioned understructure has been still incapable of
insulating, ~or example, the sounds and vibrations of a
piano placed on -the floor laid thereon.
In view of the problems of the prior art set forth
hereinbefore, the present invention seeks to provide a
novel composite pane] which has excellent sound absorbing
and insulating properties as well as in shock absorbing
capacity, and is easy to manufacture, fit for standard-
ization and mass production, and free from buckling or
~ __J
5~
warping in use.
The invention also seeks to provide a floor con-
struction incorporating composite panels of the above
character in a manner well calculated to derive the
full benefits therefrom.
Summarized briefly, the composite panel of this
invention comprises a pair of Cacings of a rigid material
and a core sandwiched therebetween. The core takes the
form of at least one sheet of elastic material which is
corrugated to provide alternating ridges and webs, with
the ridges disposed in two parallel planes and each having
an outer surface thereof bonded to either of the facings.
Further, the corrugated sheet has fibers implanted on
all its surfaces except the bonded outer surfaces o~ the
ridges.
In a preferred embodiment of the invention the
ridges of the corrugated core sheet have flat outer
surfaces so as to be firmly bondecL to the facings. The
webs of the core sheet are alternatel~ inclined in
opposite direc-tions and made thicker than the ridges.
- In additional embodiments, the core comprises two such
corrugated elastic sheets bonded to each other and to
the facings, with the ridges and webs of the two sheets
oriented either in the same direction or at right angles
to each other.
The composite panels configured as above are
particwlarly notable for their vibration damping capacity.
3~
The sound waves impinging on either of the panel
facings rapidly attenuate as they propagate through
the ridges and webs of the elastic core sheet toward
the other facing. Further the fibers implanted on
the core sheet take up the internal wave reflections.
These vibration absorbing and insulating cabilities
of the composite panels in accordance with the
invention make them admirably well suited for use as
soundproof barriers in houses and other installations.
The composite panels in accordance with the
invention are no less favorable in their ability of
absor~ing shocks and other external forces to be
exerted thereon in their use as flooring or the like.
The shape of the elastic core and the plating of fibers
thereon make the panels remarkably strong and resistive
to external forces. Rubber or like material of which
the core sheet or sheets are made need not be of any
great hardness to provide panels that are not unduly
pliant in their thickness direction. Thanks to these
characteristics the panels exhibit advantageous effects,
heretofore unattained, when used for flooring or sub-
flooring. The advantages will become particularly
pronounced when a single composite panel in accordance
with the invention is placed under a piano.
- 25 It is also noteworthy that the core of rubber or
like elastic material does not suffer permanent deforma-
tion with the lapse of time. Consequently the panel
~ s~
facings will not buckle or warp for an extended length
of time. Further, the core in the ~orm of a corrugated
sheet of rubber or the like easily lends itself to
mass production in standardized size. The facings
themselves are, of course, also mass producible in any
desired size. It is therefore possible to provide the
composite panels of this invention in the form of
standardized units at reduced cost, for the ease of use
in a wide range of applications.
According to the floor construction also proposed
by this invention, a plurality o~ composite panels,
each configured as in the ~oregoing, are joined together
by tongue-and-groove joints and laid on a floor under-
structure. Only the lower facing of each composite
panel is secured to the understructure, in a manner
subject to change depending upon the makeup of the under-
structure.
It will be appreciated that the tongue-and-grooved
composite panels of the above floor construction have
only their lower facings rigidly coupled to the floor
understructure. The upper facings float, so to say, on
the elastic cores. Thus the composite panels effectively
absorb and insulate the sound waves that are applied to
their upper facings, as has been discussed previously,
thereby minimizing the transmission of -the vibrations to
the understructure. The floor construction serves as
an e~cellent sound barrier betwéen the adjoining stories
~:~756~01
of a building. In a preferred embodiment of the inven-
tion, the floor construction further includes elastic
edge strips of recumbent U-shaped cross section for
joining the edges of the tongue-and-grooved composite
panels to walls.
The floor construction according to the invention
allows the installation of a piano or any other heavy
object thereon without the floor undergoing permanent
deformation or suffering in its sound insulating capaci~y.
The high compression strength of the inventive panels
is due in no small measure to the fibers implanted on
the elastic core sheet or sheets, as has been proved by
tests conducted by a well-reputed organization set forth
herein.
The above and other features and advantages of
this invention and the manner of attaining them will
become more apparent, and the invention itself will best
be understood, from a study of the following detailed
description and appended claims, taken together with the
attached drawings showing some preferred embodiments of
the invention.
In the drawings:
Figure l is a perspective of a preferred form of
the composite panel embodying the principles of the
present invention;
Figure 2 is a pe,rspective, on an enlarged scale,
of part of the corrugated sheet of elastic material
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i630
constituting the core of the composite panel of Figure
;
Figure 3 is a ragmentary edge view of another
preferred form of the composite panel in accordance
with the invention;
Figure 4 is a view similar to Figure 3 but show-
ing a further preferred form of the composi.te panel in
accordance with the invention;
Figure 5 is a perspective of a modified composite
panel in accordance with the invention,
Figure 6 is an enlarged, fragmentary section
through the composite panel of Figure 5;
Figure 7 is a fragmentary perspective of an elastic,
edge strip for use in the floor construction incorporat-
ing composite panels of this invention;
Figure 8 is a fragmentary perspective of an exampleof floor construction made by use of the composite panels
of the type shown in Figure l;
Figure 9 is an enlarged, fragmentary vertical
section through the floor construction of Figure 8,
the view being explanatory of the way in which each
composite panel is secured to the understructure of the
floor;
Figure 10 is a view similar to Figure 8 but ex-
planatory of the way in which the edges of the floorare joined to the walls by use of the edge strips of
Figure 7, with the representative edge strip being shown
~7563~i
on an enlarged scale in Figure 7;
Figure 11 is a fragmentary perspective of another
example of floor construction in accordance with the
invention;
Figure 12 is also a fragmentary perspective show-
ing still another example of floor construction in
accordance with the invention; and
Figure 13 is a fragmentary elevation of a further
example of 100r construction in accordance with the
invention.
Reference is first directed to Figure l in order
to describe the construction of the simplest form of
composite panel in conformity with the invention.
Generally referenced 1, the exemplified composite panel
comprises a pair of Eacings 2 and 3 of flat, rectangular
shape, and a core 4 sandwiched therebetween and glued
thereto. The term "glued," as used herein and in the
claims appended hereto, should be understood to connote
a bonded state obtained by the use of any adhesive
that can firmly bond together the facings and coxe of
various materials set forth hereinbelow.
The facings 2 and 3 of the composite panel can be
of any relatively rigid material depending upon its
intended use. Examples include solid wood, plywood,
various boards, and metal.
The core 4 of the composite panel, on the other hand,
takes the form oE a single sheet of rubber, either
31L~'7~3~
natural or synthetic, or like elastic material capable
of being glued. As illustrated on an enlarged scale
in Figure 2, the elastic sheet is corrugated to
provide alternating flat ridges 5 and flat, sloping
webs 6. The ridges 5 are disposed in two parallel
planes, and the webs 6 are alternately inclined in op-
posite directions. As viewed from either side, there-
fore, the corrugated elastic sheet is shaped like a
selies of trapezoids alternately directed in opposite
directions. The ridges 5 have their outer surfaces
glued directly to the rigid facings 2 and 3. The webs 6
serve to interconnect the ridges 5, and therefore the
facings 2 and 3, and to impart elasticity to the composite
panel 1 primarily in the thickness direction. Being
load-bearing portions, the webs 6 are made somewhat
thicker than,the ridges 5.
According to an additional, but very important,
feature of the invention, the corrugated elastic sheet
has fibers 7 implanted, electrostatically or otherwise,
as densely as possible on the inner surfaces of the
ridges 5 and on both surfaces of the webs 6. Only the
outer surface of the ridges are not fibered as they are
glued to the facings 2 and 3~ The fibers 7 are from
appro~imately one to three millimeters long for the best
results.
The above corrugated sheet of elastic material,
together with the fibers 7 thereon, makes up the core 4
_g_
~S~31~
of the composite panel 1 in accordance with the inven-
tion. The composite panel is completed as the bare
outer surfaces of the ridges 5 of the corrugated
elastic sheet are glued to the rigid facings 2 and 3.
To facilitate assemblage in flooring, for example,
either of the facings 2 and 3 of the composite panel
is provided with a tongue extending longitudinally at
least on one edge thereof and a groove extending longi-
t~dinally at least in the opposite edge thereof, so
that a plurality of such composite panels may be readily
butted together by the tongue-and-groove joints. The
tongue and groove on either facing of each panel will
be referred to in the course of the subsequent descrip-
tion of the floor constructions in accordance with the
invention.
Figures 3 and 4 illustrate two additional embodi-
ments of the invention alternative to that of Figure 1.
Each of these additional embodiments incorporate two
corrugated, fibered sheets of elastic material in
~0 superposition as the core 4, in contrast to but one
such sheet used as the core in the preceding embodiment.
~ n the embodiment of Figure 3, the two corrugated,
fibered sheets of elastic material making up the core 4
are superposed with their ridges S and webs 6 oriented
in the same direction and in register with each other.
The outer surfaces of the flat ridges 5 of the -two
superposed sheets are alternately glued to each other
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:,
~S63~
and to the facings 2 and 3. In the embodiment of Figure
4, on the other hand, the two corrugated, fibered sheets
of elastic material are superposed with their ridges S
and webs 6 oriented at right angles to each other. The
outer surfaces of the flat ridges 5 of the two sheets
are likewise glued to each other and to the facings 2 and
3.
In all the foregoing embodiments of the invention,
the edges of the cores are disposed flush with the edges
of the facings and are left exposed. This construction
may be preferred in applications where a plurality of
such composite panels are to be butted together as in
flooring. The composite panels may be used singly,
however. Thus, from an aesthetic point of view, closure
strips lO are interposed between marginal edge portions
of the facings 2 and 3 so as to enclose and conceal the
core in a modified composite panel shown in Figure 5.
These closure strips should be of elastic material similar
to, or exactly the same as, the material of the core.
Figure 6 is an enlarged, fragmentary section throu~h
the composite panel of Figure 5, showing one of the
closure strips lO as adapted for use with the two super-
posed core sheets 4 having their ridges and webs oriented
at right angles to each other as in Figure 4. It will be
noted that the representative closure strip 10 is of
rectangular cross section and has a height equal to the
thickness or height of the two superposed core sheets.
631~
The closure strip has a groove lOa formed longitudinal-
ly in one of its surfaces, and a tongue lOb formed
longitudinally in its opposite surface. (Figure 5
does not show the tongues and grooves for simplicity~)
Of course, only the tongue or groove could be formed
in the exposed surface of the closure strip. The crea-
tion of both tongue and groove on the opposite surfaces
of each closure strip is preferred, however, because of
the ease o manufacture.
The tongue-and-grooved closure strips 10 are to be
used at either or both of the two opposed pairs of
edges of the composite panel. At one edge of the panel
one closure strip is placed between the marginal edges
of the facings 2 and 3 with its tongued surface directed
outwardly and disposed flush with the facing edges. At
the opposite edge of the panel, another closure strip is
placed similarly, only with its grooved surface directed
outwardly. The closure strips are also glued to the
facings 2 and 3.
It will be appreciated that the composi-te panels
constructed as in Figure 6 can be easily united with -
each other by the tongue-and-groove joints in close-
fitting edge-to-edge relationship. Further, as the
elastic cores 4 of the composite panels yield under the
force of heavy objects placed thereon, so do the closure
strips 10 of similarly elastic material. Consequently
the facings 2 and 3 of the panels do not suffer permanent
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~L~7563~
deformation to any noticeable degree.
The ~arious forms of composite panels disclosed
hereinbefoxe all lend themselves to easy manufacture
in standardized size depending upon their intended
applications such as flooring and wall facing.
Possible standard sizes may be, for instancet 1800 by
90 millimeters or 1800 by 300 millimeters. The manu-
facture of the composite panels in standardized thick-
ness is also easy, as the panel thickness depends
largely upon the perpendicular distance between the
adjoining ridges 5 of the core 4.
~ escribed hereinbelow are several floor construc-
tions incorporating composite panels each structured
as in Figures l and 2 by way of example. In addition
to the composite panels the floor constructions employ
edge strips of elastic material, one shown in Figure 7,
for use in joining the edges of the composite panels
to walls.
With reference to FIG. 7 each edge strip ll for
use in the floor constructions of this invention is
~abricated in recumbent U-shaped cross section from
elastic material such as natural or synthetic rubber.
It comprises an upright web lla, an upper rim or flange
llb bent right-angularly from the upper edge of the web,
and a lower rim or flange llc bent right-angularly from
the lower edge of the web in the same direction as the
upper rim. The upper rim llb is of greater width than
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563~;D
the lower rim llc. The lower rim is to be placed
directly on the understructure of the floor, as are
the composite panels to ma}ce up the floor, whereas
the upper rim 11_ is to partly overlie the edge portion
of the composite panels. The height of the edge strip
11 is therefore slightly more than the thickness of
each composite panel. The manner of use, as well as
functions, of the e~ge strip will become more apparent
from the following description of the floor construc-
tions.
Generally, in the floor constructions in accord-
ance with the invention, a plurality of inventive
composite panels are jo~ned together by tongues and
grooves on a floor understructure. Only the lower
facings of the composite panels are anchored to the
understructure in a manner suiting the particular make-
up of the understructure.
Figures 8, 9 and 10 illustrate one such floor
construction adapted for usual wooden houses. The floor
understructure of such houses has sleepers or horizontal
beams, one seen at 12, on which joists 13 are fixedly
mounted crosswise and in parallel spaced relation to
each other, as best seen in Figure 8. Preferably, the
spacings between the joists 13 should not exceed 300
millimeters for the minimization of resonance.
Any required number of composite panels 1 are laid
on the joists 13. As has been mentioned in connection
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~75~
with Figure 1, each composite panel has a -tongue 8
at least on one edge of its upper facing, herein
designated 2, and a groove 9 in at least the opposite
edge. The tongue 8 on each composite panel is engaged
in the groove 9 in the neighboring panel. In so
fitting together the successive panels, their lower
facings, herein designated 3, are nailed as at 14 in
Figures 8 and 9 to the joists 13. Alternatively, the
lower facings may be glued to the joists. It will be
understood that even though the upper facings 2 of the
panels are tongue-and-groove jointed to each other,
and their lower facings 3 rigidly coupled to the joists
13, the upper facings are still elastically supported
on the cores 4.
At the edges of the floor, the edge strips 11 of
Figure 7 are placed on the understructure so as to
extend along the edges of the composite panels, as
illustrated in Figure 10. The lower rims llc of the
edge strips are held edgewise against the lower facings
3 of the panels whereas their upper rims llb a~e Placed
upon the upper facings 2 of the panels. The upper rims
are securèd to the upper facings by nailing 14 or by
gluing. Plinths forming the bases of walls are then
installed on the upper rims llb of the edge strips, as
shown at 15 in Figure 10.
With the composite panels 1 secured to the joists
13 and united with each other as above, their upper
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~:~L75~
facings 2 may still be in need of finishing to provide
a completed floor. The panel facings may be finished
as by oil-staining (if the facings are of wood),
carpeting, or flooxboarding.
Figure 11 represents another possible floor con-
struction in accordance with the invention, also adapted
for wooden houses. The floor construction includes
subflooring plywood 16 laid on and nailed or otherwise
rigidly attached to joists 13 on sleepers 12. The com-
posite panels 1 overlie the subflooring plywood 16 and
have their lower facings 3 glued thereto. Other
details of construction can be exactly as set forth
above in conjunction with the floor construction of
Figures 8 to 10.
The floor construction of Figure 11 offers some
advantages over that of Figures 8 to 10. One is that
the subflooring plywood 16 serves to substantially
increase the thickness, and therefore stiffness, of the
lower facings 3 of the composite panels 1 glued thereto.
Consequently, even if the joists 13 are unduly spaced
apart from each other, the panels possess sufficient
strength to withstand the weight of furniture or other
articles to be placed thereon. This construction is
therefore suitable for the reflooring of existing houses.
Further the panels can be installed by simple gluing.
Figure 12 illustrates the floor construction of
this invention as adapted for installation on a concrete
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~ 7563~
subfloor or understructure shown at 17. For this
application the invention dictates the attachment of
suitable anchor means to the lower facings 3 of the
composite panels 1. The anchor means are herein shown
as C-sectioned bea~s 18, which are fastened to the lower
panel facings as by screwing. The anchor beams 18
are embedded in a layer 19 of mortar cast in place on
the concrete subfloor 17. Other details of construction
are substantially as stated above in connection with
Figures 8 and 10.
In khe 100r construction of Figure 12 the height
of the anchor beams 18 should be approximately 30 milli-
meters if the thickness of the mortar layer 19 is from
40 to 50 millimeters. The dimensional difference is
intended to keep the anchor beams out of direct contact
with the concrete subfloor 17.
An additional floor construction shown in Figure
13 is also adapted for installation on the concrete sub-
floor or understructure 17. Each composite panel 1 has
a plurality of supporting columns 18' connected to its
lower facing and depending vertically therefrom. Each
supporting column terminates in a pedestal 18" of rubber,
plastic or like material to directly engage the concrete
subfloor 17. As desired or required, each supporting
column 18' may be threadedly~engaged with the lower panel
facing or with the pedestal 18" in order to make possible
the height adjustment of each composite panel 1. Other
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~56~1~
details of construction are also substantially as
stated previously in connection with Figures $ and lO.
In all the floor constructions set forth herein-
before the upper facings 2 of the composite panels 1
elastically rest, via the cores 4, on their lower
facings 3 which are rigidly secured to the floor
understructure such as the joists 13 or concrete sub-
floor 17. Further, at the edges of the floor, the
- elastic edge stxips 11 insulate the upper panel facings
from the walls. Accordingly the vibrations imparted ko
the upper panel facings are effectively absorbed by the
elastic cores and the edge strips and so are not
substantially transmitted to the lower panel facings or
to the floor understructure. It will therefore be
understood that the illustrated floor constructions are
well calculated to take full advantage of the vibration
damping capacity of the composite panels.
Particular attention should be paid to the fibers
implanted on the corrugated elastic sheet or sheets
making up the core of each composite panel. The fibers
function not merely to absorb the lnternal wave reflec-
tions of the panel but also to enhance the compression
strength of the core.
The following table represents the results of com-
pression tests conducted by Chemicals Inspection Insti-
tute, a Japanese juridical foundationl on corrugated
.sheets of elastic material with and without fibers.
-18-
~51~3Q
The test pieces were sized g5 by 150 millimeters. The
rate of compression loading was set at one millimeter
per minute~ The term "single core" in the table means
a single corrugated sheet, and the term "double core"
two corrugated sheets in superposition.
-19-
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O OO ~H ~1 ~1 ~1
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--20--
-
:~75~
It will be observed from the above table that the
elastic cores with fibers in accordance with the
inven-tion have compression streng-ths far greater than
those of the cores without fibers. The compression
strength of the fibered double core, in particular, is
two or more times as much as that of the double core
without fibers. For this rea.son the core sheet or
sheets can be made from rubber or the like of no great
hardness to provide composite panels of sufficient
strength and due resiliency suitable for use as flooring
or subflooring.
Although the various floor constructions of Figures
8 to 13 all employ composite panels structured as in
Figure 2, it will be understood that the composite
panels of Figures 3 to 6 could be used in the same floor
constructions. Additional modifications and variations
of the present invention may be resorted to without
departing from the scope of the invention.
~0
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