U.S. patent application number 11/657205 was filed with the patent office on 2007-08-23 for wooden laminated floor product to improve strength, water protection and fatigue resistance.
This patent application is currently assigned to PROLAM, SOCIETE EN COMMANDITE. Invention is credited to Benoit Risi.
Application Number | 20070193179 11/657205 |
Document ID | / |
Family ID | 38319515 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070193179 |
Kind Code |
A1 |
Risi; Benoit |
August 23, 2007 |
Wooden laminated floor product to improve strength, water
protection and fatigue resistance
Abstract
A vehicular surface floor has a length and a width, made from a
plurality of planks. Each plank has a length substantially equal to
the length of the floor and a width that is less than the width of
the floor. Each plank has first and second side surfaces and are
arranged side by side so that a first side surface of one plank
faces a second side surface of an adjacent plank, a joint region
being formed at an area where the first side surface meets the
second side surface. Each plank consists of at least two rows of
boards, and each board consists of a plurality of segments joined
end-to-end to one another by shaped coupling portions and side by
side along a glue line; so that each of the at least two rows are
longitudinally offset from an adjacent row, and a glue line of one
row is offset from a glue line from an adjacent row.
Inventors: |
Risi; Benoit; (Cap
St-Ignace, CA) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
PROLAM, SOCIETE EN
COMMANDITE
Cap St-Ignace
CA
|
Family ID: |
38319515 |
Appl. No.: |
11/657205 |
Filed: |
January 24, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60762509 |
Jan 27, 2006 |
|
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|
Current U.S.
Class: |
52/591.4 |
Current CPC
Class: |
B32B 3/12 20130101; B32B
2307/554 20130101; B32B 2307/552 20130101; B32B 2419/04 20130101;
B32B 2255/26 20130101; E04F 15/04 20130101; B32B 21/04 20130101;
B32B 3/06 20130101; B62D 29/02 20130101; B32B 3/14 20130101; B32B
21/13 20130101; B32B 2605/003 20130101; E04F 2201/023 20130101;
B32B 2255/08 20130101; E04F 15/048 20130101; B32B 2307/744
20130101; B62D 25/2054 20130101; B32B 21/042 20130101 |
Class at
Publication: |
052/591.4 |
International
Class: |
E04B 2/00 20060101
E04B002/00 |
Claims
1. A vehicular surface floor having a longitudinal length and a
lateral width, said vehicular surface floor comprising: a) a
plurality of wood planks extending longitudinally up to a length
substantially equal to the longitudinal length of said floor, each
plank having a top surface, a bottom surface opposite said top
surface, and a first and second side surfaces extending between
said top surface and said bottom surface, where said plank has a
width that is less than the lateral width of said floor, said floor
being formed of said plurality of planks arranged side by side,
each plank being formed of at least two rows of a plurality of
boards, each board being formed of a plurality of segments joined
end-to-end to one another by shaped coupling portions and side by
side along a glue line, each of said at least two rows being
longitudinally offset from an adjacent row, so that a glue line of
one row is offset from a glue line from an adjacent row; and b)
said plurality of planks being arranged side by side such that at
least one of said first and said second side surfaces of each of
said planks faces one of said second or first side surfaces of
adjacent planks to form the floor, a joint region being formed at
locations at which said first side surface faces said second side
surface of adjacent planks.
2. A vehicular surface floor according to claim 1, wherein said
plurality of wood boards are hardwood boards.
3. A vehicular surface floor according to claim 2, wherein said
hardwood is selected from the group consisting of oak, maple,
birch, beach, and larch.
4. A vehicular surface floor according to claim 1, wherein said
floor is further provided with an undercoating.
5. A vehicular surface floor according to claim 4, wherein said
undercoating is an unreinforced polymer, a paint or a
fiber-reinforced polymer.
6. A vehicular surface floor according to claim 1, wherein said
undercoating covers both substantially 100 percent of said bottom
surface, and partially or substantially covers both side surfaces
of said floor.
7. A vehicular surface floor according to claim 1 wherein said
first side surface is provided with an upper lip portion, said
second side surface is provided with a lower lip portion, and said
first side surface of one of said planks which faces said second
side surface of an adjacent plank forms a ship lap joint in which
said upper lip portion at least partially overlies said lower lip
portion.
8. A vehicular surface floor according to claim 7, wherein each of
said planks consist of only two rows of boards, and said ship lap
joint is automatically formed by offsetting a first row of boards
from a second adjacent row of boards.
9. A vehicular surface floor having a longitudinal length and a
lateral width, said floor comprising: a plurality of planks, each
plank having a length substantially equal to said length of said
floor and a width that is less than said width of said floor, each
plank having first and second side surface, said planks being
arranged side by side so that a first side surface of one plank
faces a second side surface of an adjacent plank, a joint region
being formed at an area where said first side surface meets said
second side surface, wherein: each plank consists of at least two
rows of boards; each board consists of a plurality of segments
joined end-to-end to one another by shaped coupling portions and
side by side along a glue line; each of said at least two rows are
longitudinally offset from an adjacent row, so that a glue line of
one row is offset from a glue line from an adjacent row.
10. A vehicular surface floor according to claim 9, wherein said
plurality of wood boards are hardwood boards.
11. A vehicular surface floor according to claim 10, wherein said
hardwood is selected from the group consisting of oak, maple,
birch, beach, and larch.
12. A vehicular surface floor according to claim 9, wherein said
floor is further provided with an undercoating.
13. A vehicular surface floor according to claim 12, wherein said
undercoating is an unreinforced polymer, a paint or a
fiber-reinforced polymer.
14. A vehicular surface floor according to claim 9, wherein said
undercoating covers both substantially 100 percent of said bottom
surface, and partially or substantially covers both side surfaces
of said floor.
15. A vehicular surface floor according to claim 9, wherein said
first side surface is provided with an upper lip portion, said
second side surface is provided with a lower lip portion, and said
first side surface of one of said planks which faces said second
side surface of an adjacent plank forms a ship lap joint in which
said upper lip portion at least partially overlies said lower lip
portion.
16. A vehicular surface floor according to claim 15, wherein each
of said planks consist of only two rows of boards, and said ship
lap joint is automatically formed by offsetting a first row of
boards from a second adjacent row of boards.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to laminated product to
improve the strength, water protection and the fatigue resistance
on a laminated wooden cargo-carrying floor of a cargo-carrying
body.
BACKGROUND OF THE INVENTION
[0002] Conventional wood flooring for over-the-road truck trailers
and containers is normally manufactured with hardwoods such as oak,
maple, birch, beech, etc. The green lumber used as a starting
material in such manufacture is suitably dried in special drying
chambers under controlled conditions. The dried lumber is then
sawed into strips of rectangular cross-section and defective
portions are eliminated by cross cutting the strips. After, with a
double end matching or during the cross cutting process, hooks or
knuckle-type joints are formed at the ends of the lumber strips.
The joints are a simple mechanical coupling between the ends of
opposing lumber strips without significant adhesive bonding at the
joint itself. The relatively defect-free lumber strips are coated
on their vertical sides or edges with an adhesive such as
urea-melamine formaldehyde or polyvinyl acetate. The minimum length
of the lumber strips is 12 inches, as requested by industry
standard, and a maximum length of 6 to 7 feet, which is limited by
the width of the double end matcher equipment which makes the
desired profile of the joint. The uncured edge-glue lumber strips
are then assembled by hand on a conveyor by placing them
side-by-side and one in front of other strips, which were
previously assembled.
[0003] The manual assembly of the strips is a very important
element and is essential to reach the desired mechanical properties
of the floor and meet industrial requirements. In fact, the persons
that assemble the strips must: [0004] 1) minimise the number of
joints by square foot; and [0005] 2) maximise the space between
joints in a way that it is equalised all over the wood surface.
[0006] These two elements maximise the floor's mechanical support
and its durability. The length of the lumber strips has an effect
on the number of joint par square foot and the space between the
joint. Applying heat and edge pressure to large sections of the
assembled lumber strip in a press cures the adhesive thus forming a
unitary panel.
[0007] At the output of the press, the cured laminated wood is cut
to a desired length (up to about 60 feet) and width (about 6 to 18
inches) to form boards. The boards are then planed to a desired
thickness and shiplaps and crusher beads are machined on the sides,
such as shown in FIG. 1. A shiplap is a rectangular projecting
ledge along the length on each side of a floorboard. A crusher bead
is a small semi-circular projection running along the length on
each side of a board and placed over or below a lip.
[0008] When the floorboards are assembled in a trailer such that
the side edges of corresponding boards are squeezed together, the
shiplaps of adjacent boards overlap to form a seam. The crusher
beads provide spacing between adjacent boards and help in
preventing buckling of the boards due to expansion of the board
following absorption of water. Wood putty is applied at the joints
on the top and bottom surfaces of the boards to fill any gaps.
[0009] Finally, the underside of the floorboards is coated with a
polymeric substance termed as "undercoating" to provide moisture
protection. The finished floorboards are assembled into a kit of
about eight boards for installation in a trailer.
[0010] Normally, a kit consists of two boards with special shiplaps
so that they will fit along the road and curb sides of a trailer.
The other boards may be identical in design and they are placed
between the road and curb sideboards. In some trailers, a metallic
component such as a hat-channel may be placed between any two
adjacent boards. The metallic component becomes part of the floor
area. The boards adjacent the hat-channel have machined edges
designed to mate with the flanges of the metallic component. All
the boards are supported by thin-walled cross-members of I, C or
hat sections, each having an upper flange or surface, which span
the width of the trailer and are spaced along the length of the
trailer. Each floorboard is secured to the cross-members by screws
or other appropriate fasteners extending through the thickness of
the board and the upper flanges of the cross-members.
[0011] Hardwood-based laminated wood flooring is popularly used in
truck trailers since it offers many advantages. The surface
characteristics of hardwoods such as high wear resistance and slip
resistance are most desirable. The strength and stiffness of the
flooring is important for efficient and safe transfer of the
applied loads to the cross-members of the trailer. The shock
resistance of wood is useful to withstand any sudden dropping of
heavy cargo on the floor. Nail holding capability and the ability
to absorb small amounts of water, oil or grease without
significantly affecting slip resistance are yet additional
favourable properties of hardwood flooring.
[0012] Although conventional wood flooring has many desirable
features, it also suffers from certain disadvantages. One of the
main problems is the effect of the end of each lumber strips on the
strength and durability of the floor.
[0013] It is well known in the flooring industry that the joint
between two end lumber strips is the structural weakness point of a
laminated floor for two reasons.
[0014] First, the joint reduces the capacity of the floor to react
properly to the dynamic action of a moving lift truck placing or
removing heavy cargo into the trailer. A lift truck is often used
on the trailer floor to load and unload cargo. A large amount of
the weight of the lift truck and the cargo is transferred to the
floor through the wheels of the front axle of the lift truck due to
the momentary raising of the rear axle when the lift truck is
dynamically placing or removing heavy cargo on the floor. The
dynamic action of a moving lift truck placing heavy cargo on the
trailer floor places a severe stress concentration on the floor and
some of the cross-members. Bending of the floor between two
adjacent cross-members due to any applied load on the top of the
floor has a tendency to open the hook joints and enlarge the gaps.
The effect of repeated lift truck operations on the conventional
wood floor causes considerable fatigue damage including:
de-lamination of the edge glued lumber strips near the joints
leading to the "pop-out" of the lumber strips on the underside;
crack initiation and propagation in the wood strips on the
underside of the floor due to tensile stresses; and cracking of
edge glue lines due to shearing, transverse bending and twisting of
the floor.
[0015] Second, the joint represents a weak area of protection
against water coming from the road. Capillarity and the tendency of
the end grain of wood to absorb and store water over time
eventually creates a problem of water leaks into the trailer and a
degradation of the structural integrity surrounding the joint area.
Also, because of the way that conventional floors are made, when
de-laminating occurs, the cracks will penetrate through the
laminated floor creating a weak area where the water can enter. The
combination of moisture attack and fatigue damage to the wood floor
affects its performances thus necessitating its repair or
replacement. In some cases, catastrophic structural failure of the
trailer floor system may occur leading to the unacceptable injury
to working personnel and damage to machinery.
[0016] In the past decade, and still today, the research and
development efforts to improve the disadvantages of conventional
floors are mainly focused on the use of new materials such as
plastic, fiberglass, etc., and on the interaction with wood to
create new composite floors.
[0017] The idea of using plastic, steel, fiber carbon, kevlar,
fiberglass and other material to reinforce wooden structure is not
new and has been studied by many. More recently, Padmanabhan U.S.
Pat. No. 5,928,735 and Tunis U.S. Pat. No. 6,601,357 propose
solutions in the specific field of laminated trailer floor.
[0018] Padmanabhan applies a reinforced thermoplastic ply to the
entire bottom of the floor. Because reinforced ply increases the
strength and stiffness of the trailer floor, the hardwood portion
of the floor can be thinner. The result is a stronger and lighter
trailer floor. The reinforced ply also provides a water impervious
layer protecting the entire bottom part of the floor from moisture
coming from the road.
[0019] Tunis provides a solution for moisture protection only. The
thermoplastic ply is not reinforced and has as its sole purpose the
protection of the floor from the attack of water spray and moisture
over time. The thermoplastic ply covers the entire bottom surface
of the floor.
[0020] Others have taken a different approach and have proposed
solutions improving some aspect of the laminated wood floor without
adding any composite material, but by improving the manufacturing
method or technique. In U.S. Pat. No. 6,843,877 (Risi) and in U.S.
Pat. No. 6,957,675 (Risi) there is proposed a new machine and
manufacturing method which uses a finger joint type end stick
design to improve the durability and the moisture resistance of the
laminated floor. The present invention takes that the same avenue
creating innovative solutions where an improvement of the strength
can be achieved without using composite materials but only by using
more efficiently the actual techniques of manufacturing and the
characteristics of the raw material itself.
SUMMARY OF THE INVENTION
[0021] The present invention is a new product to improve the
strength, fatigue resistance and provide moisture resistance on a
laminated wooden cargo-carrying floor of a cargo-carrying body such
as that of either a transport vehicle or a transport container,
which offer an intermediate solution to a composite floor but at a
much lower cost.
[0022] In accordance with one aspect of the present invention,
there is provided a vehicular surface floor having a longitudinal
length and a lateral width, said vehicular surface floor
comprising:
[0023] a) a plurality of wood planks extending longitudinally up to
a length substantially equal to the longitudinal length of said
floor, each plank having a top surface, a bottom surface opposite
said top surface, and a first and second side surfaces extending
between said top surface and said bottom surface, where said plank
has a width that is less than the lateral width of said floor, said
floor being formed of said plurality of planks arranged side by
side, each plank being formed of at least two rows of a plurality
of boards, each board being formed of a plurality of segments
joined end-to-end to one another by shaped coupling portions and
side by side along a glue line, each of said at least two rows
being longitudinally offset from an adjacent row, so that a glue
line of one row is offset from a glue line from an adjacent row;
and
[0024] b) said plurality of planks being arranged side by side such
that at least one of said first and said second side surfaces of
each of said planks faces one of said second or first side surfaces
of adjacent planks to form the floor, a joint region being formed
at locations at which said first side surface faces said second
side surface of adjacent planks.
[0025] In accordance with another aspect of the present invention,
there is provided a vehicular surface floor having a longitudinal
length and a lateral width, said floor comprising: [0026] a
plurality of planks, each plank having a length substantially equal
to said length of said floor and a width that is less than said
width of said floor, each plank having first and second side
surface, said planks being arranged side by side so that a first
side surface of one plank faces a second side surface of an
adjacent plank, a joint region being formed at an area where said
first side surface meets said second side surface, wherein: [0027]
each plank consists of at least two rows of boards; [0028] each
board consists of a plurality of segments joined end-to-end to one
another by shaped coupling portions and side by side along a glue
line; [0029] each of said at least two rows are longitudinally
offset from an adjacent row, so that a glue line of one row is
offset from a glue line from an adjacent row.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The present invention will be better understood after
reading a description of a preferred embodiment thereof made in
reference to the following drawings in which:
[0031] FIG. 1 is a perspective cross section of a conventional wood
floor according to the prior art;
[0032] FIG. 2 is a perspective cross section of a conventional wood
floor according to a preferred embodiment of the invention; and
[0033] FIG. 3 is a perspective view of a floor, including an
undercoat layer.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
[0034] Referring now to FIG. 2, there is shown a perspective
cross-section of a wood plank 1. A plurality of such wood planks 1
are arranged side by side to form a floor 10.
[0035] Each wood plank 1 is made of at least two layers of boards
100. Each board is made of a plurality of strips 101, each strip
being joined end-to-end at a joint region 103, and each set of
strips being joined side by side along a glue line 105.
[0036] In a preferred embodiment of the invention, the strips are
hardwood boards, and the hardwood is further preferably selected
from the group consisting of oak, maple, birch, beach, and
larch.
[0037] In accordance with a preferred embodiment of the invention,
one layer 100 is longitudinally offset from another layer 100, such
that the glue lines of one board are offset from the glue lines of
another board, as shown in FIG. 2. Although only two layers are
shown in FIG. 2, it will be understood that more layers can be used
depending on the thickness of the strips, and on the desired
overall thickness of the floor 10.
[0038] In the case of FIG. 2, the offsetting of one layer with
respect to another automatically creates the shiplap joint, leaving
only the crusher bead to be made.
[0039] It will further be appreciated that the plank of FIG. 2 can
be made as in the prior art, that is a full thickness plank, which
is then split in two and glued together, but offset, along glue
line 106. Furthermore, one of the two halves is rotated front to
back (180.degree.), so that joints do not face each other. Also, if
more than one layer is used, for example three, then instead of a
shiplap joint, a tongue-and-groove system can be used.
[0040] Furthermore, the butt end joints of the sticks of the bottom
layer do not face completely the butt end joints of the sticks of
the upper part of the floor.
[0041] As is the case of convention floors, the floor of the
present invention can be further provided with an undercoating. The
undercoating can be an unreinforced polymer, a paint or a
fiber-reinforced polymer. The undercoating further can cover
substantially 100 percent of said bottom surface or less (for
example at areas where it is more important), and partially or
substantially cover both side surfaces of said floor.
[0042] It should be pointed out that the lamination of the top to
the bottom part of the floor can be also done for other wooden
floors, such as those used in the flat bed industry. Those wooden
floors are typically not laminated and are made with solid wooden
planks of 8 inches wide by 8 to 12 feet long, with different
thicknesses (usually 1 1/4 or 1 1/2 inches thick). After the board
is planed, the plank has a ship lap in both sides, as in
conventional laminated floor, with a final thickness of 1 1/8 or 1
5/16 (1 3/8).
[0043] The new product according to the present invention offers
many advantages as follows:
[0044] It reduces the quantity of the raw material needed to
produce the same square footage; usually, conventional floors are
made with 14 sticks whereas the new product is made with only 13
sticks.
[0045] Depending on the way the new product is produced, it may
increase the productivity of manufacturing;
[0046] There is no way for the water to go through the floor
because there are no glue lines or butt end joints which go
straight from the bottom to the top;
[0047] Because of the way it is designed, even if de-lamination
does occur between sticks on one of the layers, it will be
difficult for the water to go through the floor;
[0048] Because there are no joints going straight through the
floor, the negative effect of the conventional joint is decreased,
which in turn increases the fatigue resistance when the laminated
floor is under stress during the forklift passages on the
floor.
[0049] The product according to the present invention has better
durability characteristics over the traditional laminated wooden
floor used in the industry and also offers a more economic
alternative to composite floors using reinforced ply like
fibreglass, which are very expensive.
[0050] Although the present invention has been explained
hereinabove by way of a preferred embodiment thereof, it should be
pointed out that any modifications to this preferred embodiment
within the scope of the appended claims is not deemed to alter or
change the nature and scope of the present invention.
* * * * *