[0001] The present invention refers to a device for the quick and removable clamping of
flat panels for forming concrete structures. The device brings many advantages on
the heretofore known techniques and allows a substantial stiffening of the forming
structures.
[0002] Usually the fabrication of concrete forming structures needs, for time-saving, the
composition of substantially sized forming surfaces which for practical reasons must
be built up starting from modular panels of smaller dimensions.
[0003] To this end, the bigger surfaces are built up on the construction sites by the assembly
of a number of smaller modular panels. The bigger forming surfaces or formworks are
afterwards positioned in the appropriate place by means of a crane.
[0004] The attachment fixtures used for this end need from one side to obtain the maximum
stiffness of the attached panel and in the other hand, it is convenient that the assembly
process be fast and easy to carry out in order to obtain the best manpower economy.
[0005] At present, some devices are known for the mutual attachment of concrete forming
panels which rely on conventional, traditionally known attachment fixtures such as
those commercially known having two jaws or clamping members which grip the elements
which have to be attached and with driving means made out of an helical screw. These
are tools of universal type widely used in building and in other branches of engineering.
[0006] Other attachment devices are known, which are to be considered as particular embodiments
of the above mentioned attachment means, in which the gripping mutually opposed jaws
have profiles to be more or less adapted to the beams of the panels to be attached
and which tensioning is carried out aswell by means of an helical screw and lugged
nots to be manually operated.
[0007] It is felt, therefore, the need in this branch of engineering of having devices for
the quick clamping of concrete forming panels not having to resort to helical screws
and which assembly and disassembly could be made in a faster and easier way than with
the known tensioning devices, guaranteeing at the same time, with a simplified operation,
a high force to maintain the panel in its assembly position.
[0008] The objective of this invention is obtained by means of the device which constitutes
the subject of the present Patent Application, which allows a very fast and easy assembly
and disassembly of the forming panels, insuring as well a high stiffness of the assembly.
The device features simple wedge means which can be very easily operated and which
allow, given their special design, an easy and safe handling of the device, preventing
a high rate of wear of the same.
[0009] Basically, the device of the present invention comprises a support which has a cross-section
in the form of an inverted U or rectangular tube having a lengthwise slit in which
a wedge structure is assembled with capacity to move along the slit which guides the
wedge structure in its movement. Said wedge structure is capable of exerting pressure
on an intermediate bridge which connects to parallel plates constituting a swivelling
body in which said parallel plates are attached by means of two transverse bolts.
Said parallel plates have end sections having recesses which are capable of mating
together with a part of the cross-section of the beams constituting the lateral frames
of two adjacent forming panels to be attached.
[0010] In the device according to the invention the attachment of a forming panel to the
adjacent panel to constitute a bigger forming structure is obtained by the displacement
of the wedge structure by percusion. The wedge structure moves on the guiding slit
exerting an effort on the swingeable structure which adapts with a high force against
the beams constituting the frame of the panel to be attached, pushing such panel against
the adjacent panel which is clamped by means of plates which are integral with the
device.
[0011] The operation of the swingeable structure, specially concerning the guiding and fastening
of the same, said swingeable structure consisting of the two parallel plates connected
by transverse bolts, will be complemented and improved by the arrangement of elongated
openings on the side surfaces of the rectangular tubular member of the device. Said
lateral openings receive one of the transverse bolts of the swingeable structure,
and they feature on its upper border multiple ondulations or saw teeth formations
or protusions of any other having sides which show a certain inclination, on which
inclined sides said transverse bolt will act when tensioned by means of the wedge
structure. In this way an additional vector will be created which has the tendency
to close the clamping device, assisting at the same time in the location of the swingeable
structure in the adequate place depending on the effective tensioning width which
is determined in its turn by the precise dimensions, specially the cross-section,
of the beams constituting the frames of the panels to be attached.
[0012] For its best understanding, the invention will be explained making reference to particular
embodiments, to be considered as non-limitative examples.
[0013] Figures 1 and 2 correspond respectively to an upper view of two mutually attached
concrete forming panels and to a cross-section through II-II of figure 1.
[0014] Figure 3 shows a pictorial view of a clamping device according to the present invention.
[0015] Figure 4 corresponds to a cross-section of the clamping device, shown to attach two
concrete forming panels.
[0016] Figure 5 is an upper view corresponding to figure 4.
[0017] Figure 6 and 7 show cross-sections of the clamping device through planes VI-VI and
VII-VII shown in figure 4.
[0018] Figures 8 and 9 show corresponding views of the lateral elongated openings of the
U support which receives one of the transverse bolts of the swingeable structure.
[0019] Figures 10 and 11 show two examples of eventual embodiments of the cross-sections
of the beams constituting the frames for the forming panels.
[0020] Figures 12, 13, 14 and 15 show respective successive tensioning steps of the swingeable
structure of the clamping device of the present invention, starting from the loosened
initial position, going through the stage in which the swingeable structure climbs
on the steeper part of the wedge, up to the tensioning stage which corresponds to
the section in which the wedge structure shows a lower inclination, ending in the
final attachment position.
[0021] Figure 16 shows the relative positions occupied by the two transverse bolts of the
swingeable structure in relation with the lateral edges of the protrusion formed in
the lateral openings of the rectangular support and the relative position of the effort
bearing section on the frame forming beam, showing the vectors corresponding to the
intervening forces.
[0022] As shown in the drawings, two adjacent concrete forming panels 1 and 2 are positioned
adjacent to each other, on perimetral beams -3- and -4- constituting a part of the
frames of such panels, attached by clamping means, in a variable number, as those
shown with reference numerals -5- and -6- in figure 1.
[0023] As shown in figure 3, the clamping device according to the present invention essentially
comprises a U section beam -7- which has a straight slit -8-extending lengthwise on
one of the faces -9- of the beam and which is capable of receiving a movable wedge
structure -10- to be guided on said slit and which has an upper face -11- with two
successive inclined surfaces. The device will be completed by means of a swingeable
structure which comprises two symetrically arranged side plates -12- and -13- which
are attached by means of bolts -14- and -29-. The swingeable structure may rotate
on said bolts and it is arranged in a form that the side plates will embrace the side
faces of the U element - 7- and at the same time the corresponding side faces of beam
-15- of one of the panels -1- to be attached.
[0024] The clamping device has at the same time two side plates such as -17-, figure 3,
integral with the lateral faces of beam -7-, having end hooks -18- which may adapt
to side beam -22- of one of the panels -2- to be attached.
[0025] Site plates -12- and -13- have intermediate recesses -19- which shape allows the
mating, with a certain play, with the perimetral beam -20- of forming panel -1- to
be attached. At the same time, the ends -18-of plate -17- are capable of entering
into recesses -21-of beam -22- of the other adjacent panel -2 to be attached.
[0026] By this arrangement, as shown in figure 3, the tensioning of the wedge shape structure
-10- along its guide -8- will be transformed in upward and downward displacements
for the swingeable structure, which side plates -12- and -13- will be retained by
a wedge action as shown in figure 4, so that the nose expansion -23- will contact
shoulder -24- of beam -20-, with generation of a main effort as shown by vector -25-
which decomposes in a component -26- a second component -27-. By reaction, a wedge
effect will be generated between the inclined section -24'- of beam -22- and the end
-18- of plate -17-integral with support -7-, generating an effort shown by vector
-25'- which, in its turn, decompose in a component -27'- and the second component
-26'-.
[0027] Component forces -27- and -27' - compress adjacent panels -1- and -2- together and
component forces -26- and -26'-compress said panels against the support -7-, stiffening
the assembly.
[0028] The side elongated openings -31- may adopt the form shown in figure 8, with an ondulated
upper edge, or alternatively the form shown in figure 9, which consists of a curved
section -30- at one of the ends of the openings of any such form that generally may
allow to have an intermediate angled section in such side openings -31-to obtain an
additional force which may be represented by a vector directed in the sense of closing
the clamping device.
[0029] For the composition of larger forming surfaces, a series of forming panels may be
assembled together and in case that the overall dimensions of the surface to be composed
do not correspond to a multiple of the width of one panel, recourse will be taken
to complementary elements to be inserted between said panels.
[0030] The ondulated edge -31- in the example of figure 8, shows in its upper border a number
of substantially semi-circular recesses and protrusions respectively -33-and -32-
so that transverse bolt -29- may lodge itself within any of said recesses -33- depending
on the width on which the present clamping device must be used, which will change
according to the width defined by the forming panels and the eventual complementary
elements to be used in case that the total width is not a multiple of the width of
the individual forming panels.
[0031] In the operation of the clamping device, the bolt -29- of the swingeable structure
will climb placing itself in the vicinity of one of the recesses -33- of the upper
border of the opening. Upon continuation of the driving impacts on the wedge structure
of the clamping device, the bolt -29- will lodge itself in one of the recesses -33-and
the swingeable structure constituted by elements -12-, -13, -14- and -29- will rotate
on bolt -29- compressing its end portion -23- on the ramp -24- of the beam -20-generating
a force which has been represented by vector -25- and by effect of the reaction, the
same force will be exerted on beam -22- of adjacent plate -2- as previously stated.
[0032] As it may be easily understood, according to the dimensions of the complementary
elements to be used, the bolt -29- will place itself in the curved section which is
closer to its position.
[0033] In case that no complementary element will be used, the opening -28- will have only
one recess -30- for receiving the bolt -29- as shown in figure 9.
[0034] Figures 12, 13, 14, and 15 show some successive stages of the clamping of the device,
the first of such figures shows the loose or tensionless situation of the device in
which the swingeable structure rests by the transverse bolts -14 and -29- respectively,
on the flat end surface of wedge -11- and on lower border of opening -31-.
[0035] Upon beginning the displacement of the wedge structure -11- as shown in figure 13,
the section which forms a bigger angle shown with reference numeral -34-will induce
the first raising of the swingeable structure, the bolt -29- reaching a position close
to the upper border which has the recesses -33-. The continuation of the tensioning
action by means of wedge structure -11-, will make the bolt -14- to slide on the section
with a smaller angle of said wedge structure, reaching the bolt -29- a position which
is close to the working section. Subsequently, when the hook or expansion -23- engages
the surface -24- of the beam forming part of the frame of the panel, the transverse
bolt -29- will engage the slant surface -37- of the protrusion in the border which
has an ondulated form, saw teeth structure or any other similar, forming such slanted
surface -37- which will give ground to the efforts shown in figure 16, in which is
to be appreciated that the force exerted by the wedge structure on bolt -14- will
induce a force represented by vector Fo which in the engagement area between expansion
-23- and surface -24- will be transformed in a force represented by vector -25- which
horizontal component -27- will enhance the closing of the device. Similarly, the engagement
action of bolt -29- on slanted surface -27- will produce an effort represented by
vector F1, which reaction -35-will act on the swingeable structure, so that its horizontal
component represented by vector -36- will operate as well in the sense of closing
the swingeable structure, that is, in the sense of tensioning the clamping device.
Therefore, the total closing forces to be obtained in the sense of closing the device
will be constituted by the addition of both vectors or horizontal components -27-
and -36-.
[0036] It will be understood that with the arrangement of means provided by this invention,
the tensioning and releasing of the clamping device will be made easier and at the
same time a high compression force will be obtained on the beams forming the frames
of the panel to be attached, this being the guaranty of a higher stability of the
clamping device.
[0037] It is to be understood as well that in the generation and maintenance of the operative
efforts in this clamping device, an important role will be paid by the elastic deformation
produced on the elements engaged under the force generated by the wedge structure
as this effect will mean the generation of permanent efforts of a magnitude which
is equivalent to said elastic deformations.
1. Device for the quick clamping of panels for forming concrete structures characterized
in that it comprises a tubular element with U cross-section which is adapted to lay
on respective transverse beams of two adjacent forming panels to be attached together,
having such tubular element a lengthwise slit in the face opposed to said beams of
the panels, in which slit a wedge structure may slide, which wedge structure shows
two slanted successive active surfaces, for the engagement of an uper transverse bolt
of a swingeable structure constituted by two parallel plates connected by such upper
bolt and a second intermediate bolt, which swingeable structure embraces one of the
beams corresponding to one of the adjacent panels to be attached, engaging such parallel
plates by its ends on slanted sections of a beam constituting the frame of said panel,
whereas the beam constituting the frame of the opposed panel to be attached will be
engaged by means of plates which are integral with said tubular element having U cross-section.
2. Device for the quick clamping of flat frames for the forming of concrete structures
according to claim 1, characterized in that each of the parallel plates constituting
the swingeable structure has an end hooklike protrusion to engage with the beam constitution
the frame of one of the two adjacent panels to be attached, which swingeable structure,
by action of the sliding wedge structure, is capable to rotate on one of the two connection
bolts, generating an engagement force between said swingeable structure and said beam.
3. Device for the quick clamping of flat frames for the forming of concrete structures
according to claim 2, characterized in that the area which receives the compression
efforts in the protrusion of the side plates of the swingeable structure and the beam
corresponding to the frame of the forming plate, has a certain inclination to generate
an effort decomposing in a first component directed towards the opposing panel and
a second perpendicular component.
4. Device for the quick clamping of flat frames for the forming of concrete structures
according to claim 1, characterized in that the tubular element with U cross-section
has two integral plates which protrute towards the side of the tubular element opposed
to the guiding slit, ending in corresponding hooklike protrusions which may engage,
under a reaction force induced by the wedging action of the swingeable structure on
one of the beams of the frame forming part of the adjacent panel in mating section
of one of the beams corresponding to the opposed forming panel, to be clamped by the
device.
5. Device for the quick clamping of flat frames for the forming of concrete structures
according to claim 1, characterized by elongated openings on the lateral surfaces
of the tubular element with U cross-section, within which elongated opnenings the
intermediate bolt of the swingeable structure may slide, having the upper borders
of such openings a number of recesses and protrusions which constitute slanted surfaces
aimed at receiving the intermediate bolt when the clamping device is to be tensioned.
6. Device for the quick clamping of flat frames for the forming of concrete structures
according to any of the aforegoing claims, characterized in that the elongated openings
of the tubular element with U cross-section have its upper borders straight in the
majority of its length, showing a unique curved recess in one of its ends.
7. Beams to compose the perimetral frame of forming panels to be attached together by
the clamping device according to the aforegoing claims, characterized in that the
beams show in cross-section a slanted profile aimed at the engagement with the hooklike
protrusions of the plates of the swingeable structures and also with the hooklike
protrusions of the plates which are integral with the tubular element with U cross-section.
8. Beams to compose the perimetral frame of forming panels to be attached together by
the clamping device according to claim 7, characterized in that the slanted section
for the engagement of the hooklike protrusion extends itself in a second slanted outward
protruding section.
9. Beams to compose the perimetral frame of forming panels to be attached together by
the clamping device according to claim 7, characterized in that the slanted engagement
section of the beam extends itself in a vertical section.