 |
Claims  |
|
|
What is claimed is:
1. A load supporting reinforced structural member, comprising:
a solid structural member of relatively incompressible plastic having a
surface defining a major plane, said solid structural member having a
lengthwise dimension;
a notch formed in said solid structural member extending inwardly with
respect to said major plane and having a side edge extending inwardly with
respect to said major plane, said notch being elongated along said
lengthwise dimension of said solid structural member; and
an untensioned reinforcing bar formed from a material having
characteristics of resilience and compressibility different from those of
said solid structural member, said bar being embedded in said notch and
being substantially complementary in shape to said notch with the embedded
sides of said reinforcing bar being in direct contact with the sides of
said notch, and said bar also being elongated along said lengthwise
dimension of said solid structural member, the relative characteristics of
resilience and compressibility of said structural member and said
reinforcing bar being such that said reinforced structural member is less
subject to deformation and has greater resilience and strength than either
said solid structural member or said reinforcing bar alone, and is of
sufficient strength to permit its usage as a load support in place of a
wooden structural member.
2. The reinforced structural member of claim 1, wherein said notch has an
outermost edge which is flush with said surface defining said major plane.
3. The reinforced structural member of claim 2, wherein said bar has an
outermost edge which is also flush with said surface defining said major
plane.
4. The reinforced structural member of claim 1, wherein said notch has an
outermost edge which is recessed from said surface defining said major
plane.
5. The reinforced structural member of claim 1, wherein said solid
structural member is made of extruded plastic.
6. The reinforced structural member of claim 1, wherein said solid
structural member consists of extruded recycled plastic, extruded virgin
plastic, or a combination of extruded recycled and virgin plastic.
7. The reinforced structural member of claim 1, wherein said reinforcing
bar is formed of a metal.
8. The reinforced structural member of claim 7, wherein said metal is
steel.
9. The reinforced structural member of claim 1, wherein said solid
structural member is prismatic in shape in the form of a slat.
10. The reinforced structural member of claim 1, wherein said notch has an
outermost edge which is flush with said outer surface.
11. The reinforced structural member of claim 10, wherein said bar has an
outermost edge which is also flush with said outer surface.
12. The reinforced structural member of claim 1, wherein said notch has an
outermost edge which is recessed from said outer surface.
13. The reinforced structural member of claim 1, wherein said solid
structural member is made of extruded plastic.
14. The reinforced structural member of claim 1, wherein said solid
structural member consists of extruded recycled plastic, extruded virgin
plastic, or a combination of extruded recycled and virgin plastic.
15. The reinforced structural member of claim 1, wherein said reinforcing
bar is formed of a metal.
16. The reinforced structural member of claim 15, wherein said metal is
steel.
17. The reinforced structural member of claim 1, wherein said reinforcing
bar is formed of wood.
18. The reinforced structural member of claim 1, wherein said solid
structural member is prismatic in shape in the form of a slat.
19. The reinforced structural member of claim 1, wherein said notch and
said bar extend substantially the entire length of said solid structural
member.
20. The reinforced structural member of claim 1, wherein said notch and
said bar extend substantially the entire length of said solid structural
member.
21. A load supporting reinforced structural member, comprising:
a solid structural member of relatively incompressible plastic having an
outer surface and a lengthwise dimension;
a notch formed in said solid structural member extending inwardly from said
outer surface and having a side edge extending inwardly with respect to
said outer surface, said notch being elongated along said lengthwise
dimension of said solid structural member; and
an untensioned reinforcing bar formed from a material having
characteristics of resilience and compressibility different from those of
said solid structural member, said bar being embedded in said notch and
being substantially complementary in shape to said notch with the embedded
sides of reinforcing bar being in direct contact with the sides of said
notch, and said bar also being elongated along said lengthwise dimension
of said solid structural member, the relative characteristics of
resilience and compressibility of said structural member and said
reinforcing bar being such that said reinforced structural member is less
subject to deformation and has greater resilience and strength than either
said solid structural member or said reinforcing bar alone, and is of
sufficient strength to permit its usage as a load support in place of a
wooden structural member.
22. A load supporting reinforced structural member, comprising:
a solid structural member of relatively incompressible plastic having an
outer surface, said solid structural member having a lengthwise dimension,
at least some of said plastic being recycled plastic;
a notch formed in said solid structural member extending inwardly from said
outer surface, said notch being elongated along said lengthwise dimension
of said solid structural member; and
an untensioned metal reinforcing bar having characteristics of resilience
and compressibility different from those of said solid structural member,
said bar being embedded in said notch and being substantially
complementary in shape to said notch with the embedded sides of said
reinforcing bar being in direct contact with the sides of said notch, and
said bar also being elongated along said lengthwise dimension of said
solid structural member, the relative characteristics of resilience and
compressibility of said structural member and said reinforcing bar being
such that said reinforced structural member is less subject to deformation
and has greater resilience and strength than either said solid structural
member or said reinforcing bar alone, and is of sufficient strength to
permit its usage as a load support in place of a wooden structural member.
23. The reinforced structural member of claim 22, wherein said notch has an
outermost edge which is flush with said outer surface.
24. The reinforced structural member of claim 23, wherein said bar has an
outermost edge which is also flush with said outer surface.
25. The reinforced structural member of claim 24, wherein said notch has an
outermost edge which is recessed from said outer surface.
26. The reinforced structural member of claim 22, wherein said plastic is
an extruded plastic.
27. The reinforced structural member of claim 22, wherein said metal is
steel.
28. The reinforced structural member of claim 22, wherein said solid
structural member is prismatic in shape in the form of a slat.
29. The reinforced structural member of claim 22, wherein said notch and
said bar extend substantially the entire length of said solid structural
member.
30. A load supporting reinforced structural member, comprising:
a solid structural member of plastic having a surface defining a major
plane, said solid structural member having a lengthwise dimension;
a notch formed in said solid structural member extending inwardly with
respect to said major plane and having a side edge extending perpendicular
to said major plane, said notch being elongated along said lengthwise
dimension of said solid structural member; and
an untensioned reinforcing bar formed from wood and having characteristics
of resilience and compressibility different from those of said solid
structural member, said bar being inserted in said notch and being
substantially complementary in shape to said notch, and said bar also
being elongated along said lengthwise dimension of said solid structural
member, said reinforced structural member is less subject to deformation
and has greater resilience than either said solid structural member or
said reinforcing bar alone.
31. A load supporting reinforced structural member, comprising:
a solid structural member of plastic having a surface defining a major
plane, said solid structural member having a lengthwise dimension;
a notch formed in said solid structural member extending inwardly with
respect to said major plane and having a side edge extending perpendicular
to said major plane, said notch being elongated along said lengthwise
dimension of said solid structural member;
an untensioned reinforcing bar formed from a material having
characteristics of resilience and compressibility different from those of
said solid structural member, said bar being inserted in said notch and
being substantially complementary in shape to said notch, and said bar
also being elongated along said lengthwise dimension of said solid
structural member, said reinforced structural member is less subject to
deformation and has greater resilience than either said solid structural
member or said reinforcing bar alone; and
locking means for locking said reinforcing bar into said notch.
32. The reinforced structural member of claim 31, wherein said locking
means comprises a plurality of holes through said solid structural member
on either side of said notch, a plurality of holes formed in said
reinforcing bar in alignment with said holes in said solid structural
member, and a plurality of fasteners inserted into said holes through said
solid structural member and said reinforcing bar.
33. A load supporting reinforced structural member, comprising:
a solid structural member of plastic having an outer surface and a
lengthwise dimension;
a notch formed in said solid structural member extending inwardly from said
outer surface and having a side edge extending perpendicular to said outer
surface, said notch being elongated along said lengthwise dimension of
said solid constructional member; and
an untensioned reinforcing bar formed from a material having
characteristics of resilience and compressibility different from those of
said solid structural member, said bar being inserted in said notch and
being substantially complementary in shape to said notch, and said bar
also being elongated along said lengthwise dimension of said solid
constructional member, said reinforced structural member is less subject
to deformation and has greater resilience than either said solid
structural member or said reinforcing bar alone; and
locking means for locking said reinforcing bar into said notch.
34. The reinforced structural member of claim 33, wherein said locking
means comprises a plurality of holes through said solid structural member
on either side of said notch, a plurality of holes formed in said
reinforcing bar in alignment with said holes in said solid structural
member, and a plurality of fasteners inserted into said holes through said
solid structural member and said reinforcing bar.
35. A load supporting reinforced structural member, comprising:
a solid structural member of plastic having an outer surface, said solid
structural member having a lengthwise dimension, at least some of said
plastic being recycled plastic;
a notch formed in said solid structural member extending inwardly from said
outer surface, said notch being elongated along said lengthwise dimension
of said solid structural member;
an untensioned metal reinforcing bar having characteristics of resilience
and compressibility different from those of said solid structural member,
said bar being inserted in said notch and being substantially
complementary in shape to said notch, and said bar also being elongated
along said lengthwise dimension of said solid structural member, said
reinforced structural member is less subject to deformation and has
greater resilience than either said solid structural member or said
reinforcing bar alone; and
locking means for locking said reinforcing bar into said notch.
36. The reinforced structural member of claim 26, wherein said locking
means comprises a plurality of holes said solid constructional member on
either side of said notch, a plurality of holes formed in said reinforcing
bar in alignment with said holes in said solid constructional member, and
a plurality of fasteners inserted into said holes through said solid
constructional member and said reinforcing bar. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to composite structural units. More
specifically, the invention relates to a reinforced structural member of
recycled plastic and a method for making such a structural member.
2. Related Art
Because wood is subject to splintering, rotting, discoloration, attack by
insects, and other undesirable effects upon long-term exposure to the
elements, plastic has been substituted for wood in a number of outdoor
applications, particularly furniture and related accessories. As the
public has become more conscious of the need for conservation, there have
been attempts to employ recycled plastics in making outdoor furniture,
accessories, decking, walkways, etc.
Unfortunately, recycled plastic in the form required for outdoor furniture,
such as slats for benches, has limited strength when subjected to such
forces as may be incurred under ordinary use; and is extremely subject to
deformation when subjected to relatively low heat and stress, such as may
be experienced during the warmer months. Thus, furniture of recycled
plastic tends to sag and not recover after only a short period of use.
This problem of sag can be avoided by using a very high density plastic.
However, very high density plastic is prohibitively expensive, does not
address the societal need to recycle, and requires the use of large
amounts of virgin material.
It is known to reinforce extruded or molded plastic members with imbedded
elements wherein the elements provide the member with a higher strength,
and the plastic material provides resistance to corrosion, an attractive
appearance, and protects the element.
U.S. Pat. No. 5,096,645 issued to Fink teaches that extruded thermoplastic
members, particularly structural members, can be reinforced by
longitudinally extending pre-stressed elements, such as filaments or
matting. The elements, while under tension, are drawn into an extrusion
crosshead die forming the thermoplastic member. The elements are fully
imbedded within the thermoplastic material while under tension. Curing of
the thermoplastic material, and final curing of the tensioned reinforcing
elements, if a thermosetting resin impregnated element is used, occurs
while the elements are under tension. The material of the member and the
elements intimately bond and the tension forces within the elements
reinforce the member at the desired locations.
U.S. Pat. No. 3,928,691 issued to Knudson teaches a polyurethane panel
system having mutually opposing, longitudinally extending, semi-circular
grooves for receiving metallic reinforcing rolls. The rolls are disposed
between the edges of adjacent panels, the panels being secured together
using an epoxy resin.
U.S. Pat. No. 3,470,598 issued to Berthelsen provides a structural member
made of plastic which is extruded over a metallic reinforcement. The
method of producing such composite structure comprises the steps of
punching perforations of selective sizes and varying spacing in respective
portions of a continuous length of a metallic sheet strip, rolling the
strip into the form of a desired profile with the curved portions of the
profile containing more widely spaced perforations than the flat portions,
and extruding synthetic resin to effectively cover opposite surfaces of
the metallic profile with opposite layers which are connected through the
perforations of the metallic strip.
U.S. Pat. No. 2,645,115 issued to Abeles teaches a structural member
comprising a plurality of aligned blocks having a single continuous groove
and a metallic reinforcing member under tension disposed therein. In one
embodiment, the structural member is made of plastic.
Netherlands Patent No. 7,700697 provides an extruded hollow plastic member
having an internally disposed metallic reinforcement. The plastic member
is typically made by extrusion.
All of the foregoing patents teach a pre-stressing of reinforcing elements
within plastic materials, or otherwise require manufacturing or assembly
steps which are fairly complicated and expensive.
SUMMARY OF THE INVENTION
Thus, it is an object of the invention to provide a plastic structural
element useful for outdoor and indoor applications and in other
applications where a wood substitute may be desirable, which is reinforced
to prevent sagging due to exposure to the forces of normal use.
Another object of the invention is to provide a plastic structural member
which can be formed by extrusion and which is reinforced using an insert
member without the need for tensioning the insert member.
It is another object of the invention to provide a plastic structural
member with an insert member having characteristics of resilience and
compressibility different from those of the plastic in which the different
characteristics of the plastic and the material of the insert member cause
the insert member to reinforce the plastic structural member, while the
beneficial characteristics of the plastic (its relative incompressibility)
prevent deformation of the insert member in its weaker cross-section.
It is still another object of the invention to provide a reinforced
structural member comprising two dissimilar materials put together in an
odd geometry to create a resilience and memory which neither one alone
possesses.
It is an additional object of the invention to provide a method of making a
plastic structural member having an insert member.
These and other objects of the invention are achieved by the provision of a
reinforced structural member comprising a plastic structural member having
a metallic insert member or bar inserted therein without tension or
pre-stressing.
The present invention takes advantage of the relative characteristics of
plastics and metal, and particularly recycled plastics and steel. Plastic
materials, particularly extruded recycled plastic materials, have limited
compressibility and are relatively dense. Such plastic materials have some
rigidity and strength in their major plane, but very little, if any,
resilience in their minor plane. In contrast, metal, and steel in
particular, is resilient and rigid in the major plane. Both plastic and
metal are relatively weak and are less resilient in their minor plane.
As used herein, the major plane of an object is defined with reference to
the direction in which force will be exerted on the structural member in
use; specifically the major plane is defined as a plane which is
perpendicular to the direction of the force. The minor plane of an object,
as used herein, is a plane perpendicular to the major plane.
Metal, and particularly steel, can be used to advantage in reinforcing
plastic materials, and structural members of recycled plastics in
particular. The limited incompressibility of the plastic structural member
prevents flexing of an elongated steel insert member in the minor plane of
the steel insert member, while the rigidity of the steel insert bar or
member prevents flexing of the plastic structural member in the minor
plane of the plastic structural member. Thus, the metal insert member can
be inserted into the plastic structural member without the need for
tensioning or pre-stressing, contrary to the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is better understood by reading the following Detailed
Description of the Preferred Embodiments with reference to the
accompanying drawing figures, in which like reference numerals refer to
like elements throughout, and in which:
FIG. 1 is a perspective view illustrating a first embodiment of the
invention;
FIG. 2 is a perspective view partially in cross-section as taken along line
2--2 of FIG. 1;
FIG. 3 is a perspective view illustrating a second embodiment of the
invention;
FIG. 4 is a perspective view partially in cross-section as taken along line
4--4 of FIG. 3;
FIG. 4A is a perspective view partially in cross-section of a third
embodiment of the invention;
FIG. 4B is a perspective view partially in cross-section of a fourth
embodiment of the invention;
FIG. 5A is a perspective view partially in cross-section of a fifth
embodiment of the invention; and
FIG. 5B is a perspective view partially in cross-section of a sixth
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing preferred embodiments of the present invention illustrated in
the drawings, specific terminology is employed for the sake of clarity.
However, the invention is not intended to be limited to the specific
terminology so selected, and it is to be understood that each specific
element includes all technical equivalents which operate in a similar
manner to accomplish a similar purpose.
FIGS. 1-4 illustrate first and second embodiments of a reinforced
structural member 10 and 100, respectively, utilizing the concepts of the
invention. As shown in FIGS. 1-4, plastic is extruded to form a solid
structural member 12. The plastic can be all recycled, a combination of
recycled and virgin, or all virgin. As illustrated in FIGS. 1-4,
structural member 12 is a rectangular prism. However, it should be
understood that other shapes can be employed, including but not limited to
triangular prismatic, square prismatic, pentagonal prismatic, cylindrical
etc. Solid structural member 12 has a surface 12a defining a major plane.
In the first embodiment of the invention, shown in FIGS. 1 and 2, the major
plane coincides with one of the wider sides of structural member 12, thus
making reinforced member 10 suitable for use as, for example, a slat in a
conventional garden bench, picnic table, or bench, or a plank for a deck.
In the second embodiment of the invention, shown in FIGS. 3 and 4, the
major plane coincides with one of the narrower sides of the structural
member 12, thus making reinforced member 100 suitable for use as, for
example, a beam supporting the planks of a deck.
A notch 14 is formed in solid structural member 12 by milling or other
means, extending inwardly with respect to the surface 12a which defines
the major plane. As shown in FIGS. 1-4, the outermost edge of notch 14 is
contiguous with surface 12a. However, as shown in FIGS. 4B and 5B the
outermost edge of, notch 14 can also be recessed from the surface.
Notch 14 has a dimension extending parallel to the direction of force, and
perpendicular to surface 12a of solid structural member 12. Thus, in the
first embodiment of the invention as shown in FIGS. 1 and 2, the side
edges of notch 14 are perpendicular to a wide side of structural member
12, while in the second embodiment of the invention as shown in FIGS. 3
and 4, the outermost edge of notch 14 are perpendicular to a narrow side
of structural member 12. As shown in FIGS. 1-4, notch 14 has a rectangular
prismatic shape. However, as will be described in greater detail below
with respect to FIGS. 4A, 4B, 5A, and 5B, notch 14 can be T-shaped,
L-shaped, or even corrugated (i.e., sinusoidal). In the case of those
shapes also, the outermost edge of notch 14 can be either contiguous with
the surface of structural member 12 or recessed from the surface.
An untensioned reinforcing bar 16 having a shape substantially
complementary to that of notch 14 is inserted, for example by being
driven, into notch 14 to provide a uniform reinforcement throughout solid
structural member 12. Although, as shown in FIGS. 1-4, bar 16 has a
rectangular prismatic shape, it can also be T-shaped (as shown in FIGS. 4A
and 4B), L-shaped (as shown in FIGS. 5A and 5B), or corrugated
complementary to the shape of notch 14, so that bar 16 is matingly
received in notch 14, where the outermost edge of notch 14 lies flush with
surface 12a (as shown in FIGS. 1-4, 4A, and 5A), bar 16 can be dimensioned
also so that its outermost edge lies flush with surface 12a, or it can be
dimensioned so that its outermost edge is recessed from surface 12a. Where
the outermost edge of notch 14 is recessed from surface 12a (as shown in
FIGS. 4B and 5B), bar 16 has substantially the same dimensions as notch
14.
Reinforcing bar 16 can be made from recycled metal, for example, recycled
steel from old automobile bodies. Although bar 16 preferably is formed of
a metal, it can also be formed of any other material, even wood, which has
characteristics of resilience and compressibility different from plastic.
Reinforcing bar 16 is locked into notch 14 by the density of solid
structural member 12. Reinforcing bar 16 can be further locked into notch
14 by other locking means. For example, as best shown in FIGS. 2 and 4, a
plurality of holes or apertures 18 are provided through solid structural
member 12, extending from a side of structural member 12 perpendicular to
surface 12a and through notch 14. A plurality of holes or apertures 20 are
provided through reinforcing bar 16 in alignment with holes or apertures
18 of solid structural member 12. Fasteners such as screws 22 extend
through holes or apertures 18 and 20 to affix reinforcing bar 16 in
position. In the case where the fasteners are screws 22 are used,
preferably, holes or apertures 18 are counterbored, so that the heads of
screws 22 will lie flush with the side of structural member 12. However,
it will be appreciated by those of skill in the art that other fasteners
such as dowels, pegs, etc. can be used in place of screws 22.
Because both reinforcing bar 16 and screws 22 or other fasteners are flush
with or recessed from all surfaces of solid structural | | |
