U.S. patent application number 11/046379 was filed with the patent office on 2006-08-17 for transparent construction form.
Invention is credited to Johannes Wilhelmus van de Camp.
Application Number | 20060180733 11/046379 |
Document ID | / |
Family ID | 36392612 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060180733 |
Kind Code |
A1 |
van de Camp; Johannes
Wilhelmus |
August 17, 2006 |
Transparent construction form
Abstract
A wound construction form comprising a plurality of flexible
sheet material layers wound one upon another about an axis and
bonded together to form a tube, wherein all of the flexible sheet
material layers comprise transparent polymer film. The tube thus is
transparent such that a settable composition poured into the tube
can be seen through the tube wall. If an air bubble is present
adjacent the wall, it can be eliminated while the composition is
still fluid by puncturing the wall with a small hole at the bubble
so that the air can escape and the composition can fill the
void.
Inventors: |
van de Camp; Johannes
Wilhelmus; (Hartsville, SC) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA
101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Family ID: |
36392612 |
Appl. No.: |
11/046379 |
Filed: |
January 28, 2005 |
Current U.S.
Class: |
249/48 |
Current CPC
Class: |
E04G 13/021 20130101;
E04G 9/00 20130101 |
Class at
Publication: |
249/048 |
International
Class: |
E04G 13/02 20060101
E04G013/02 |
Claims
1. A tubular construction form, comprising: a plurality of flexible
sheet material layers wound one upon another about an axis and
bonded together so as to form a tube having a wall encircling the
axis, all of the flexible sheet material layers comprising
transparent polymer film, whereby the tube is transparent such that
a settable composition poured into the tube is visible from outside
the tube through the wall of the tube.
2. The tubular construction form of claim 1, wherein the flexible
sheet material layers are bonded together with an adhesive between
the flexible sheet material layers, and the adhesive comprises a
transparent adhesive.
3. The tubular construction form of claim 1, wherein the flexible
sheet material layers are bonded together by at least partially
melting the flexible sheet material layers and fusing the flexible
sheet material layers together.
4. The tubular construction form of claim 1, wherein the flexible
sheet material layers comprise polyethylene film.
5. The tubular construction form of claim 1, wherein the flexible
sheet material layers comprise polypropylene film.
6. The tubular construction form of claim 1, wherein the flexible
sheet material layers comprise polyvinyl chloride film.
7. The tubular construction form of claim 1, wherein the flexible
sheet material layers comprise polyvinyl chloride film and are
bonded together with a transparent adhesive between the flexible
sheet material layers.
8. The tubular construction form of claim 7, wherein the adhesive
comprises acetone.
9. The tubular construction form of claim 1, wherein the tube
comprises from 2 to 20 flexible sheet material layers.
10. The tubular construction form of claim 1, wherein the tube
comprises from 2 to 15 flexible sheet material layers.
11. The tubular construction form of claim 1, wherein the tube
comprises from 2 to 10 flexible sheet material layers.
12. The tubular construction form of claim 1, further comprising a
release material disposed on an inner surface of the wall to
facilitate removal of the construction form from the settable
composition after setting thereof, the release material being
transparent.
13. The tubular construction form of claim 12, wherein the release
material comprises silicone.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to wound tubes, and more
particularly to wound tubular construction forms for poured
concrete columns and the like.
[0002] Tubular construction forms heretofore have been formed as
spirally wound paperboard tubes. When concrete is poured into the
form, air bubbles can be present in the concrete, which is
undesirable from an aesthetic standpoint when the bubbles are on
the outer surface of the resulting column. However, until the
concrete has set and the form is removed, there is no way to know
if air bubbles are present. It is known to insert a vibrating
needle into the wet concrete to vibrate the concrete, which can
help in eliminating air bubbles. The vibrating needle cannot be
used very near the tubular form, however, because the vibrations
can damage the form. Thus, even when the needle is used, air
bubbles can be present adjacent the form. The air bubbles are
manifested as recesses on the outer surface of the column when the
form is removed. If a bubble is large, the resulting recess can
compromise the column strength. Small bubbles may not affect
strength to any significant extent, but do mar the appearance of
the column. The recesses can be filled by hand, but the repairs
remain visible unless the column is subsequently painted.
BRIEF SUMMARY OF THE INVENTION
[0003] The present invention addresses the above needs and achieves
other advantages, by providing a wound construction form comprising
a plurality of flexible sheet material layers wound one upon
another about an axis and bonded together to form a tube, wherein
all of the flexible sheet material layers comprise transparent
polymer film. The tube thus is transparent such that a settable
composition poured into the tube can be seen through the tube wall.
If an air bubble is present adjacent the wall, it can be eliminated
while the composition is still fluid. For instance, the wall of the
tube can be punctured with a small hole at the bubble so that the
air can escape and the composition can fill the void. The small
hole will not compromise the strength of the form and will tend to
be closed by the composition after the air escapes.
[0004] The flexible sheet material layers can be formed of various
polymer compositions, including but not limited to polyethylene,
polypropylene, polyvinyl chloride, and the like. The layers can be
bonded together either by a transparent adhesive, or by at least
partially melting the layers and fusing them together (e.g., by
thermal welding/heat sealing). The transparent adhesive can
comprise any of various known transparent adhesives capable of
adhering well to the particular polymer film composition used to
form the tube.
[0005] The transparent construction form can comprise various
numbers of flexible sheet material layers, from two to 20 or more,
depending on the thickness of the layers and the strength
requirements in each case. The wall thickness of the tube can range
from about 0.02 inch to about 0.10 inch. The inside diameter of the
tube can range from about 12 inches to about 36 inches. However,
the invention is not limited to any particular number of layers,
wall thickness, or diameter.
[0006] A coating or layer of release material can be provided on
the inner surface of the form to facilitate removal of the form
from the column after setting of the settable composition.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0007] Having thus described the invention in general terms,
reference will now be made to the accompanying drawings, which are
not necessarily drawn to scale, and wherein:
[0008] FIG. 1 is a perspective view of a construction form in
accordance with one embodiment of the invention, shown filled with
a settable composition; and
[0009] FIG. 2 is a cross-sectional view along line 2-2 in FIG. 1,
illustrating how an air bubble is eliminated in accordance with the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The present inventions now will be described more fully
hereinafter with reference to the accompanying drawings, in which
some but not all embodiments of the inventions are shown. Indeed,
these inventions may be embodied in many different forms and should
not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0011] A transparent construction form 10 in accordance with one
embodiment of the invention is shown in FIGS. 1 and 2. The form
comprises a plurality of flexible sheet material layers 12, 14, 16,
18 wound one upon another about an axis and bonded together so as
to form a tube having a wall encircling the axis. In accordance
with the invention, all of the flexible sheet material layers
comprise transparent polymer film. The layers are bonded together
in a suitable fashion that does not impair the transparency of the
tube wall. For instance, the layers can be adhesively joined by a
transparent adhesive. Alternatively, the layers, when formed of a
thermally weldable material, could be thermally welded by
heat-sealing or the like.
[0012] In the illustrated embodiment, there are four transparent
film layers 12, 14, 16, 18, but transparent construction forms in
accordance with the invention can have from two to 20layers, or
from two to 15 layers, or from two to 10 layers. Furthermore, the
illustrated form 10 is constructed by spirally winding discrete
polymer film plies 12, 14, 16, 18 one upon another, but it is also
possible to convolutely wind a single sheet of film for a plurality
of turns to build up the desired number of layers.
[0013] The transparent film material can comprise various polymer
compositions, including polyethylene, polypropylene, polyvinyl
chloride, and the like. Each of the film layers can have a
thickness ranging from about 0.076 mm (0.003 inch) to about 0.635
mm (0.025 inch), and more preferably about 0.254 mm (0.010 inch) to
about 0.381 mm (0.015 inch).
[0014] Polyvinyl chloride film layers advantageously can be adhered
together with acetone and maintain sufficient transparency for the
purposes of the present invention.
[0015] Other transparent adhesives that can be used include MEK
(methyl ethyl ketone), and cyano-acrylates.
[0016] Transparent construction cores in accordance with the
invention can have various dimensions. The inside diameter can
range from about 0.15 m (6 inches) up to about 1.07 m (42 inches),
more preferably about 0.3 m (12 inches) up to about 0.91 m (36
inches). The wall thickness can vary from about 0.6 mm (0.024 inch)
up to about 5 mm (0.2 inch), or more preferably up to about 2.5 mm
(0.1 inch). Forms of smaller diameter can have a smaller wall
thickness, while larger-diameter forms generally require a larger
wall thickness.
[0017] An example of a suitable polyvinyl chloride film useful in
the practice of the invention is PENTAPRINT BX M 280/80 film from
Klockner Pentaplast of America, Inc., of Gordonsville, Va. 22942.
This film has a specific gravity of 1.33, a tensile yield strength
of 6600 psi, and a minimum elongation at break of 180%. It is
available in thicknesses from 3 to 25 mils.
[0018] The transparency of the construction form 10 enables a
settable composition 20 poured into the form to be seen through the
wall of the form. Therefore, if an air bubble 22 is present in the
composition at the inner surface of the form, it can be seen and
remedied before the composition sets. With reference to FIG. 2, the
air bubble can be eliminated by puncturing a small hole in the wall
of the form at the location of the bubble, using a suitable tool
24. The tool can be a hollow tube or needle through which the air
in the bubble can be extracted. Alternatively, the tool can be
withdrawn from the hole and the air can escape through the hole
until the settable composition flows to fill in the space
previously occupied by the air. The composition will tend to plug
up the hole once all the air has escaped.
[0019] The construction form 10 optionally can include a coating of
a release material 26 on the inner surface of the tubular wall that
is contacted by the settable composition. The release material
facilitates release of the construction form from the composition
after it has set. Various release materials can be used, such as
silicone-based compounds or the like.
[0020] From the foregoing description, it will be understood that
the transparent construction form has distinct advantages over
prior-art fiber construction forms. In addition to allowing air
bubbles to be identified and eliminated, the transparent
construction form also is water-resistant. The form thus can be
exposed to water without being substantially affected. Furthermore,
the form can have a thin wall and therefore can be flexible such
that the cross-sectional shape of the form readily conforms to a
circle under the pressure exerted by the settable composition. In
contrast, if a thick-walled fiber form starts out non-circular
because of warpage or other reasons, the stiffness of the form may
prevent the form from assuming a circular shape. The invention thus
facilitates production of columns that are round.
[0021] Many modifications and other embodiments of the inventions
set forth herein will come to mind to one skilled in the art to
which these inventions pertain having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the inventions are
not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the appended claims. Although specific terms
are employed herein, they are used in a generic and descriptive
sense only and not for purposes of limitation.
* * * * *