U.S. patent application number 11/952083 was filed with the patent office on 2008-10-16 for pillar formwork.
This patent application is currently assigned to MAX FRANK GMBH & CO. KG. Invention is credited to Ludwig Penzkofer.
Application Number | 20080251686 11/952083 |
Document ID | / |
Family ID | 7708570 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080251686 |
Kind Code |
A1 |
Penzkofer; Ludwig |
October 16, 2008 |
Pillar Formwork
Abstract
A column formwork for use in concrete construction is described,
including a planar member 1 constituting the formwork, and at least
one connecting section provided for form-fit connecting two
opposing edges 3, 3' of the planar member (1) and thus for
constituting a tube segment, wherein at least the
connecting-section surface facing the planar member 1 exhibits a
substantially constant curvature that substantially corresponds to
the curvature of the tube segment.
Inventors: |
Penzkofer; Ludwig;
(Leiblfing, DE) |
Correspondence
Address: |
CROCKETT & CROCKETT, P.C.
26020 ACERO, SUITE 200
MISSION VIEJO
CA
92691
US
|
Assignee: |
MAX FRANK GMBH & CO. KG
|
Family ID: |
7708570 |
Appl. No.: |
11/952083 |
Filed: |
December 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10497592 |
Jun 3, 2004 |
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PCT/DE02/04393 |
Nov 29, 2002 |
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11952083 |
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Current U.S.
Class: |
249/48 |
Current CPC
Class: |
E04G 13/021 20130101;
E04G 9/08 20130101 |
Class at
Publication: |
249/48 |
International
Class: |
E04G 13/02 20060101
E04G013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2001 |
DE |
101 80 441.6 |
Claims
1. A column formwork for use in concrete construction, comprising:
a single formation (1), said single formation comprising a glass
fiber reinforced elastic synthetic material having a thickness of
1.4 to 2.5 mm, and at least one connecting section provided for
positively connecting two opposing edges (3, 3') of the single
formation (1) and thus for forming a tube segment from the single
formation; wherein at least a connecting-section surface (4, 4')
facing the formation (1) exhibits a substantially constant
curvature and the curvature substantially corresponds to a
curvature of the tube segment.
2. The column formwork according to claim 1, characterized in that,
additionally, the connecting-section (2,2') surface (5, 5') facing
away from the formation (1) exhibits a constant curvature, this
curvature differing from the curvature of the tube segment.
3. The column formwork according to claim 1, characterized in that
the connecting section (2, 2') is constructed of synthetic
material.
4. The column formwork according to claim 1, characterized in that
the connecting section (2, 2') is constructed of a polyester or of
a fiber reinforced synthetic material.
5. The column formwork according to claim 1, characterized in that
the formation (1) and the connecting section (2,2') consist of the
same material.
6. The column formwork according to claim 1, characterized in that
the connecting section (2, 2') extends in the direction of the
tube-segment axis over the entire length of the tube segment.
7. A column formwork for use in concrete construction, comprising:
a single formation (1), said single formation comprising a glass
fiber reinforced elastic synthetic material having a thickness of
1.4 to 2.5 mm, and two connecting sections (2, 2') provided for
positively connecting two opposing edges (3, 3') of the single
formation (1) and thus for forming a tube segment from the single
formation; wherein a connecting-section surface (4,4') facing the
formation (1) exhibits a substantially constant curvature and the
curvature substantially corresponds to a curvature of the tube
segment.
8. The column formwork according to claim 7, characterized in that,
additionally, the connecting-sections (2, 2') include a surface
(5,5') facing away from the formation (1) which exhibits a constant
curvature, this curvature differing from the curvature of the
formation (1).
9. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') exhibit, in the direction of a
formation (1) tangent perpendicular to a formation (1) axis, an
extension (t) of 1 to 50% of the circumference of the tube
segment.
10. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') exhibit, in the direction of a
formation (1) tangent perpendicular to a formation (1) axis, an
extension (t) of 5 to 15% of the circumference of the tube
segment.
11. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') exhibit, in the direction of a
tube-segment tangent perpendicular to a tube-segment axis, an
extension (t) of 10 to 100 mm.
12. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') exhibit, in the direction of a
formation (1) tangent perpendicular to a longitudinal axis of the
formation (1), an extension (t) of 30 to 50 mm.
13. The column formwork according to claim 7, characterized in that
the connecting sections (2,2') are constructed of synthetic
material.
14. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') are constructed of polyester or of
a fiber reinforced synthetic material.
15. The column formwork according to claim 7, characterized in that
the formation (1) and the connecting sections (2,2') consist of the
same material.
16. The column formwork according to claim 7, characterized in that
the connecting sections (2, 2') extend in the direction of the
tube-segment axis over the entire length of the tube segment.
Description
[0001] This application is a continuation of U.S. application Ser.
No. 10/497,592, filed Jun. 3, 2004.
FIELD OF THE INVENTION
[0002] The present invention is directed to a column formwork for
use in concrete construction.
BACKGROUND OF THE INVENTION
[0003] Column formworks are used in concrete construction to build
columns, supports, or similar concrete elements. Recently, in
addition to conventional steel and wood formworks, wound formworks
of sheet metal, cardboard, or synthetic material have increasingly
been employed. In the case of wound cardboard formworks, the outer
formwork tube, which primarily serves to hold the formwork
together, is constructed of paperboard or cardboard. After the
column has been concreted and the concrete has set, the outer
formwork element is removed by tearing it open by means of an
integrated tear strip.
[0004] A column formwork comprising a multilayered wound flat
material is known from DE 295 18 077. The flat material is a
polyethylene-coated paper sheet. Due to the multilayered winding,
paper layers and polyethylene layers alternate in the wall of the
formwork tube in this column formwork.
[0005] DE 296 09 259 discloses a column formwork comprising a tube
segment divided along its longitudinal axis. Connecting means are
provided in the area of the dividing line to hold the formwork
together. To construct this column formwork, a tube segment is slit
open once along its longitudinal axis. To ensure simple removal, it
is recommended that the column formwork be constructed of a
synthetic material that can be bent apart when removing the
formwork. To the inside of the column formwork is applied an
auxiliary formwork material, which avoids form marks resulting from
the dividing line.
[0006] These known column formworks have various disadvantages in
common. For one thing, the formworks exhibit an extremely large
volume, thus causing problems, particularly during transportation,
that are reflected in high costs. The column formwork interior,
provided for filling up with concrete, is nothing other than dead
volume during transportation, and thus only a very small quantity
can be transported in each load. The column formwork according to
DE 296 09 259 also exhibits this problem, as it involves
shape-retentive synthetic material tubing that can be bent apart
briefly with sufficient expenditure of force only during
removal.
[0007] Moreover, the above-described column formworks are
single-use products, as the outer formwork element is removed from
the cured concrete by tearing it open. Reuse of the column formwork
is thus excluded. In the case of the column formwork according to
DE 296 09 259, this problem is solved only partially. Although the
outer part of the formwork can be reused, the necessary interior
lining having e.g. a tube of thin paperboard is a single-use
product.
DISCLOSURE OF THE INVENTION
[0008] This is where the present invention begins. It is intended
to provide a column formwork that can be reused and easily
transported. According to the present invention, this object is
solved by the column formwork according to independent claim 1.
Other advantageous aspects, details, and embodiments of the present
invention are evident from the dependent claims, the description,
and the drawings.
[0009] The present invention is based on the idea of using, not, as
previously typical, prefabricated tubes as column formworks in
concrete construction, but rather planar members equipped with
connecting sections, through which a form-fit connection of two
opposing edges of the planar member is possible. The material
comprising the planar member must satisfy two conflicting
conditions: on one hand, it must exhibit sufficient strength to
withstand the pressure of the poured concrete, and on the other
hand, it must exhibit sufficient elasticity to be able to be bent
into a tube with no difficulty. In particular, this tube must
remain dimensionally stable, that is, circular in diameter, under
the pressure of concrete, that is, after the concrete is
poured.
[0010] The column formwork according to the present invention for
use in concrete construction comprises a planar member constituting
the formwork, and at least one connecting section, provided for
form-fit connecting two opposing edges of the planar member and
thus for forming a tube segment, wherein at least the
connecting-section surface facing the planar member exhibits a
substantially constant curvature that substantially corresponds to
the curvature of the tube segment. In this way, it is achieved that
the column formwork takes on a round shape. If connecting sections
having no curvature are used, the bent planar member would take on
a slightly tear-shaped form and thus cause unsatisfactory results
in the concrete parts. Slight differences between the curvature of
the connecting section and the curvature of the tube segment are
tolerated within the context of the present invention, since
acceptable results can be obtained nonetheless.
[0011] The column formwork according to the present invention can
be transported with no difficulty in large quantities in a flat
state before bending it into a tube.
[0012] The use of the term "substantially constant curvature" is
intended to make clear that manufacturing-dependent deviations from
a constant curvature are, of course, tolerated, as long as they are
not so marked that the column formwork exhibits a diameter that
deviates substantially from a circular diameter.
[0013] According to a preferred embodiment of the present
invention, the planar member comprises an elastic synthetic
material. Such a material fulfills the two above-mentioned
conditions especially well, namely sufficient shape-retentiveness
after the concrete is poured and, at the same time, sufficient
elasticity that allows bending into a tube with no difficulty. Such
a column formwork exhibits the great advantage that no single-use
materials are provided, such as the typically used cardboard, thus
facilitating multiple reusage of the formwork.
[0014] The two opposing edges of the planar member must be form-fit
connected together. To do this, at least two connecting sections
are generally used. Advantageously, each of these connecting
sections is attached to the planar member flush with one edge of
the planar member. However, in the context of the present
invention, the connecting sections can, in principle, also be
attached to the planar member at a short or even a somewhat long
distance from the edges to be connected. In such a case, the
tongues described below for connecting the connecting sections must
be adjusted accordingly in their dimensions or e.g. replaced by
flexible bands.
[0015] However, an embodiment having just one connecting section
attached near an edge of the planar member and protruding over this
edge is also conceivable. The part of the connecting section
protruding out over the edge is then connected with the planar
member near the opposing edge after the planar member is bent into
a tube segment. This connection can, in principle, take place in
any manner, for example through glueing. However, the planar member
can also exhibit e.g. projections that engage in corresponding
recesses of the connecting section and thus facilitate a secure
form-fit connection of the opposing edges.
[0016] Although the two above-mentioned conditions "stability of
dimension" and "elasticity" are naturally fulfilled to a sufficient
extent by a number of materials that can, in principle, be used in
any thickness, certain materials used in certain thicknesses yield
particularly good results for the purpose of very easy handling.
For these reasons, both the use of fiber reinforced materials, of
fiber reinforced synthetic materials, or of polyester, especially
synthetic fiber reinforced materials, glass fiber reinforced
materials, and carbon reinforced materials, especially glass fiber
reinforced materials or carbon reinforced synthetic materials,
especially fiber reinforced polyester, as the elastic synthetic
material, and a planar member having a thickness of 0.5 to 5 mm,
especially having a thickness of 1 to 4 mm, particularly preferably
having a thickness of 1.2 to 3 mm, are preferred embodiments of the
present invention. Planar members having a thickness of 1.4 to 2.5
mm are particularly well suited, and those having a thickness of
1.5 to 2 mm are most particularly preferred.
[0017] For reasons of reduced variety of form of the connecting
sections, the connecting-section surface facing away from the
planar member can additionally be provided with a substantially
constant curvature, this curvature then differing from the
curvature of the tube segment. In this way, a connecting section
can be used for column formworks of varying diameters.
[0018] Although the column formworks according to the present
invention can be used for concreting columns of greatly varying
diameters, and in principle even for concreting columns of any
diameter, column formworks having a typical concrete construction
diameter of 100 to 2000 mm, especially of 200 to 1000 mm, are
preferred. Diameters of 200 to 450 mm, of 250 to 500 mm, of 500 to
900 mm, and of 600 to 1000 mm are particularly preferred.
[0019] The connecting sections can be affixed to the planar member
in various ways, namely e.g. through glueing, riveting, nailing, or
welding. Glueing the connecting section and the planar member is
particularly preferred because doing so causes no visible traces in
the finished concrete parts.
[0020] Column formworks having connecting sections that exhibit, in
the direction of the tube-segment tangent perpendicular to the
tube-segment axis, an extension of 1 to 50%, especially 3 to 25% of
the tube-segment diameter, are particularly preferred embodiments
of the present invention. This ensures that, after the concrete is
poured into the formwork, the connecting sections do not detach
from the planar member. Pouring the concrete creates strong forces
perpendicular to the formwork wall, and there is thus a risk of the
formwork breaking apart along the planar member edge held together
by the connecting sections. To prevent such breaking apart, the
connecting sections must be appropriately tightly connected
together, and an appropriately strong connection between connecting
section and planar member must be ensured. For this reason,
connecting sections that exhibit, in the direction of the
tube-segment tangent perpendicular to the tube-segment axis, an
extension of 5 to 15%, especially of about 10% of the tube-segment
diameter, are most particularly preferred.
[0021] In view of the above-mentioned column diameters typical in
concrete construction, connecting sections that exhibit, in the
direction of the tube-segment tangent perpendicular to the
tube-segment axis, an extension of 10 to 100 mm, especially from 20
to 75 mm, are preferred. Connecting sections that exhibit, in the
direction of the tube-segment tangent perpendicular to the
longitudinal axis of the tube segment, an extension of 30 to 50 mm,
especially of 35 to 45 mm, are particularly preferred.
[0022] In principle, the connecting sections can be constructed of
any kind of sufficiently dimensionally stable material. The
connecting sections are preferably constructed of synthetic
material, and the connecting sections are particularly preferably
constructed of polyester, of a fiber reinforced synthetic material,
especially of glass fiber reinforced synthetic material or carbon
reinforced synthetic material, particularly preferably of glass
fiber reinforced polyester or carbon reinforced polyester.
[0023] Most particularly advantageous characteristics result when
the connecting sections and the planar member comprise the same
material. In this way, an especially simple and tight connection
between the parts is possible through glueing.
[0024] To ensure a secure, form-fit connection of the opposing
edges of the planar member, in the context of the present
invention, it is particularly preferred that the connecting
sections extend in the direction of the tube segment axis over the
entire length of the tube segment. In this way, the edges of the
planar member can be form-fit connected over the entire length of
the column formwork with particularly great strength and
precision.
[0025] The connecting sections can, in principle, be mechanically
connected with one another in any manner known in formwork
engineering, thus for example using clamps, wedges, locks, or
bolts. In the context of the present invention, connecting sections
that exhibit grooves and tongues are preferred. To connect the
edges of the planar member, one tongue of one connecting section
engages in a groove of the other connecting section with a precise
fit. The stable cohesion of the edges of the planar member is
ensured e.g. through a bolt that is guided through bores in the
connecting sections and then screwed down.
[0026] Another important condition for achieving good results in
the form of an excellent surface finish of the concrete columns is
preventing water and cement paste from penetrating the formwork. At
the junction of the edges of the planar member, there is a risk
that, in the case of an insufficiently form-fit junction, water
penetration and thus bleeding of fine concrete components could
occur at the seam. This can cause visible unevenness on the surface
of the concrete column. For this reason, a planar member and
connecting sections are preferably used whose edges are especially
smooth due to an appropriate subsequent treatment such as grinding
or polishing, and that facilitate a very good, precisely fitting
connection. Furthermore, according to a particularly preferred
embodiment of the present invention, the tongues of the connecting
sections are equipped with seals, thus preventing penetration of
water through the connecting sections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention is intended to be explained in greater detail
below by reference to an exemplary embodiment in association with
the drawings, wherein
[0028] FIG. 1 shows a cutaway of a cross-section through a column
formwork according to the present invention;
[0029] FIG. 2 shows a part of a cross-section through a column
formwork according to the present invention, having a larger
diameter compared with the column formwork of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 shows a cutaway of a cross-section through a column
formwork. The planar member 1 is equipped with the connecting
sections 2 and 2', which are each attached adjacent to the edges 3,
3' of the planar member. The connecting-section surface 4, 4'
facing the planar member 1 exhibits a constant curvature, the
curvature substantially corresponding to the curvature of the tube
segment. In this way, it is achieved that the column formwork takes
on a precisely round shape. The connecting-section surface 5, 5'
facing away from the planar member likewise exhibits a constant
curvature, the surface 5, 5' of the connecting section shown being
more sharply curved than the surface 4, 4'. The edges 3, 3' of the
planar member 1 exhibit a highly precise fit. The connecting
section 5 is equipped with two tongues 6, while the connecting
section 5' exhibits two corresponding grooves. However, each of the
two connecting sections can also be equipped with one tongue and
one groove. The connection between the two connecting sections and
thus the positive connection of the two edges of the planar member
results through an engagement of the tongues 6 in the corresponding
grooves. The penetration of water through the connecting sections
2, 2' is prevented by the longitudinally running seals 7. The
required securing of the connection through a clamp that covers the
two connecting sections 2, 2', or a bolt that is guided through the
two connecting sections 2, 2' and then screwed down, is not
shown.
[0031] FIG. 2 likewise shows a cutaway of a cross-section through a
column formwork. In FIG. 2, the extension t of connecting section 2
in the direction of the tube-segment tangent perpendicular to the
axis of the tube segment is emphasized.
List of Reference Numbers
[0032] 1 Planar member
[0033] 2, 2' Connecting section
[0034] 3, 3' Edges of the planar member
[0035] 4, 4' Connecting section surface facing the planar
member
[0036] 5, 5' Connecting section surface facing away from the planar
member
[0037] 6 Tongues
[0038] t Extension of a connecting section in the direction of the
tube-segment tangent perpendicular to the tube segment axis
* * * * *