COLLAPSIBLE INSIDE CORNER FORM

COFFRAGE D'ANGLES RENTRANTS REPLIABLE

English Abstract

A corner form assembly for forming inside corners of concrete structures,
including first form subassembly for forming a first surface of the concrete
structure and a second form subassembly for forming a second surface of the
concrete structure oriented at an angle less than 180~ relative to the first
surface. A corner form assembly is pivotally attached to the second form
assembly for movement between a set position for forming the concrete
structure and a folded position. The corner form assembly is releasably
secured to the first form assembly when in the set position and is provided
with a relief angle to permit folding of the second form assembly relative to
the concrete structure.

French Abstract

La présente invention concerne un ensemble de coffrage d'angles servant à former des angles rentrants de structures en béton, lequel ensemble comprend un premier sous-ensemble de coffrage servant à former une première surface de la structure en béton et un deuxième sous-ensemble de coffrage servant à former une deuxième surface de la structure en béton orientée selon un angle inférieur à 180° par rapport à la première surface. Un ensemble de coffrage d'angles est fixé pivotant au deuxième ensemble de coffrage de façon qu'il puisse passer d'une position fixe permettant de former la structure en béton à une position pliée, et inversement. L'ensemble de coffrage d'angles est fixé libérable au premier ensemble de coffrage lorsqu'il est en position fixe et comporte un angle de dépouille permettant de plier le deuxième ensemble de coffrage par rapport à la structure en béton.

Claims

We claim:
1. An inside corner form apparatus for use in forming the inside corner of a
concrete
structure, comprising:
(a) a first form subassembly for forming a first surface of the concrete
structure;
(b) a second form subassembly for forming a second surface of the concrete
structure
oriented at an angle less than 180° relative to the first surface;
(c) a corner form assembly pivotally attached to the second form assembly for
movement between a set position for forming the concrete structure and a
folded
position;
(d) connectors releasably securing the corner form assembly to the first form
assembly when in the set position; and
(e) a relief angle of the corner form assembly to permit folding of the second
form
assembly relative to the concrete structure.
2. An inside corner form assembly as defined in claim 1, wherein the second
surface is
oriented at a 90° angle relative to the first surface.
3. An inside corner form assembly as defined in claim 1, wherein the first
form assembly
comprises a pair of form sections interconnected for relative pivotal movement
between a set
position for forming the concrete structure and a folded position.
6

Description

CA 02624742 2008-03-31
WO 2007/041608 PCT/US2006/038707
.OO~~i~~S~i$~~~''k INSIDE CORNER FORM
Background of the hlvention
[00011 This application claims priority to United States Patent Application
Serial No.
60/722,632, filed September 30, 2005.
(00021 Field of the Invention
f00031 The invention relates generally to apparatus used in forming concrete
structures
and, more specifically, to a concrete forming apparatus for use in forming
corners of a
concrete structure.
[00041 Background of the Prior Art
[00051 Concrete formiiig apparatus is in wide use in the construction of
buildings, bridges,
and other concrete structures. A common system for forming concrete structures
uses a
plurality of form components that are adapted to be assembled into a wide
variety of
configurations to conform to virtually any architectural requirement. Such
forming apparatus
components are typically made of metal so that they are strong enough to
support the heavy
weight of poured concrete and durable so that the components can be reused
many times.
[00061 One of the configurations that is most frequently encountered in
constructing
concrete structures is the right angle corner. To form a wall having a corner,
two sets of
forms must be constructed, an inside corner form and a corresponding outside
corner fomi
that is spaced from the inside corner form by the thickness of the wall to be
formed between
the two forms. Once the concrete has been poured and has set sufficiently, the
forms must be
stripped from the wall. This usually does not present a problem on the outside
corner form
where there is sufficient room to separate the form components and release
them from the
wall. On the inside corner form, however, the form components frequently are
difficult to
disassemble and release from the wall because of the inside corner geometry
and because of
the pressure that is exerted on the forms by the poured concrete.
[00071 Another issue faced in the forming of concrete wall corners is that
long runs of
concrete form assemblies will often meet at a corner where the form components
must fit
together with close tolerances. During the actual construction of a concrete
structure, there
are inevitably variations in the assembly of the components and preparation of
the site that
must be acconunodated. Conventional corner forming apparatus have required the
use of

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hancf~btiilt'igp6ud''rEHifi4ns,:M~'fi -~
eseieiime-consuming and can require a relatively high
level of skill to build. Additionally, the hand-built spacers or shims
frequently cannot be
reused and so must be constructed anew each time the forms are reset.
[0008] One approach to forming corners has been the use of form components
that are
fabricated with the predetermined angle, most commonly a right angle (90 ).
These form
components suffer from the disadvantage of having a shape that prevents them
from lying flat
during shipping and storage. Further, such fabricated corner forms cannot be
stripped from
an inside corner until the adjacent form components have been removed.
[0009] It is advantageous to have the ability to interconnect the various
components of the
corner forming apparatus in a wide variety of configurations without unduly
multiplying the
number of distinct components that are required to assemble the corner forming
apparatus of
the desired diversity of dimensions and which will readily accommodate the
typical range of
variations found in the field.
Summary of the Invention
[0010] The invention consists of an inside corner concrete form that is hinged
to facilitate
setting and stripping of the form. The form includes two cooperating form
subassemblies that
are hinged to permit folding of each of the form assemblies during setting and
stripping of the
forms. A first form assembly includes two sub-forms that are interconnected by
a hinge. When
set to form a concrete structure, the two sub-forms of the first subassembly
are aligned to present
a planar surface against which the plastic concrete is poured and set. After
the plastic concrete
has set, the sub-forms are stripped from the wall and can be folded relative
to each other about
the pivot axis of the pin. In a preferred embodiment, the two-sub forrns are
folded to
substantially a right angle relative to each other. The second form
subassembly also includes two
sub-forms that are interconnected by a hinge as in the first form subassembly
and a second, inside
corner sub-form, to create a subassembly that is foldable between a setting
position which is
substantially L-shaped in transverse cross section and a stripped position
which is substantially J-
shaped in transverse cross-section. When set to form a concrete structure, the
two sub-forms of
the second subassembly are aligned relative to the hinge to present a first
planar surface and a
second planar surface that is at an obtuse angle relative to the first planar
surface. After the
concrete has set, the second sub-form is folded or pivoted about the hinge
toward the first sub-
2

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forrrf'i; 9a:ri&'tH~J~liif~o'~t th-e set concrete structure, the obtuse angle
provides
clearance to pezmit pivoting of the second sub-form.
[0011] In the folded configuration, the transverse extension of each the two
subassemblies are
reduced so as to provide worker access between the subassemblies and the
formed concrete
structure. The novel inside corner form of the present invention eliminates
the need for shims or
other worker-made adaptations and is easily set up and stripped in close
quarter situations.
[0012] An object of the invention is to provide a form apparatus for forming
corners of a
concrete structure that can be easily and readily stripped from the formed
wall.
[0013] A further object of the invention is to provide a form apparatus for
forming corners of
a concrete structure that are provided in a limited range of dimensions to
allow selection in the
field to reduce the need for hand-built spacers or shims without requiring a
large inventory of
components.
[0014] These and other objects of the invention will be made apparent to those
skilled in the
art upon a review and understanding of this specification, the associated
drawings, and the
appended claims.
Brief Description of the Drawings
[0015] Fig. 1 is a top view of the inside corner form of the present invention
shown in the
setting position is assembly with other modular form components for forming an
inside corner of
a concrete structure.
[0016] Fig. 2 is an enlarged detail view of a corner element of the inside
corner form of the
present invention.
[0017] Fig. 3 is a plan view corresponding to Fig.1 after the inside corner of
the concrete
structure has been poured and set and the inside corner form of the present
invention stripped and
folded.
Detailed Description of Preferred Embodiments
[0018] Referring to the drawings, there is illustrated in Fig. 1, generally at
10, an inside corner
form of the present invention. The inside corner form 10 includes two
subassemblies, a first
subassembly, illustrated generally at 12, and a second subassembly,
illustrated generally at 14.
The first subassembly includes a first planar wall form 16 and a second planar
wall form 18 that
are interconnected by a hinge form assembly 20 that is releasably secured to
the wall forms 16
3

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and Q-8 ii~'f"IMUiaotnh~n~ Thus the two wall forms 16 and 18 are pivotal
relative
to each other about the axis of the hinge at 24. In a preferred embodiment,
the end of the wall
form 18 opposite the hinge has an end face that is perpendicular to the
concrete structure being
formed and is secured to a reverse bias form 25 having an angled end face with
an obtuse bias of
135 .
[0019] The second subassembly 14 also includes a first planar wall form 26 and
a second wall
form 28 that are interconnected by a hinge form assembly 30 that is releasably
secured to the wall
forms 26 and 28 by nut and bolt combinations 32. Thus the two wall forms 26
and 28 are pivotal
relative to each other about the axis of the hinge at 34. In a preferred
embodiment, the end of the
wall form 28 opposite the hinge is has an angled end face with a 45 acute
bias.
[0020] A corner assembly 36 is releasably secured to the biased edge of the
wall form 28 by
nut and bolt combinations 38. The corner assembly 36 has a first wall form
face 40 and a second
wall form face 42 that is oriented at an obtuse angle relative to the first
wall form face 40, as best
illustrated in Fig. 2. The other end face 48 of the corner assembly 36 is
parallel to the first wall
form face 40 and is releasably secured to the perpendicular end face of a bias
form 25 by nut and
bolt combinations 50, the bias form 35 also having an opposite angled end face
with an acute
bias of 45 which, upon assembly as illustrated in Fig. 1, is secured to the
reverse bias face of the
reverse bias form 25 by nut and bolt combinations 37.
[0021] In assembly to form an inside corner of a concrete structure, as
illustrated in Fig. 1, the
outer surface of the concrete structure is formed against the face panels of a
plurality of planar
concrete forms 52. The form subassemblies 12 and 14 are positioned a spaced-
apart distance
from and facing the forms 52. A plurality of tie rod assemblies 54 are used to
hold the forms 12,
14, and 52 at their pre-selected spaced-apart distance. With the forms
assembled, plastic
concrete is poured in the space between the forms and allowed to set. In the
preferred
embodiment illustrated in Fig. 1, a right-angle wall segment is formed having
an inside corner
defined by the corner assembly 36.
[0022] Once the concrete is set, the forms are stripped from the formed
concrete structure 56
(Fig. 3). This is accomplished by removing the nut and bolt coinbinations 37
that interconnect
the two form subassemblies 12 and 14 byway of the reverse bias form 25 and the
bias form 35,
respectively, and the associated tie rods 54. The first subassembly 12 is then
pulled away from
4

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, .:,.,,_ ...,~ .,,,,. .. ,,,,,. _ ,,.,
the f~Y'i~ed~Eco ii~b~atef~ace~~a!ti~~stl~eh~fd7ded toward the first planar
wall section 16 about hinge
20. Next, the corner assembly 36 and its attached second wall forms 28 and 35
are folded about
hinge 30 toward the first wall form 26 and moved away from the formed concrete
structure.
Note that the obtuse angle of the corner assembly 36 is required in order to
strip the second
subassembly 14 because the pivot 38 of the hinge 30 is spaced away from the
formed concrete
surface.
[0023] Although the invention has been described with respect to a preferred
embodiment
thereof, it is to be also understood that it is not to be so limited since
changes and modifications
can be made therein which are within the full intended scope of this invention
as defined by the
appended claims.