Note: Descriptions are shown in the official language in which they were submitted.
CA 02686528 2009-11-05
FASTENING CLAMP FOR CONNECTING WOODEN PARTS
Description
The invention relates to a fastening clamp for connecting
wooden parts to one another and to a foundation according
to the preamble of Claim 1, as is used in particular for
planks of balcony and terrace covers in the outdoors.
Connections of wooden parts with the goal of fastening two
parallel planks to a foundation in the outdoors so that, on
the one hand, an air gap and a space for working the wood
are located between the planks and, on the other hand, an
air gap - for air circulation and as a measure against
rotting - are also located between the foundation and the
planks, are known.
A spacer bracket is put between the planks in the
longitudinal direction in current practice and narrow
bracket parts are laid under the planks as the foundation,
in order to achieve a typical spacing of at least 5 mm. The
fastening is then performed using screws, using which the
planks are fastened vertically through the support bracket
parts on the foundation. The spacer brackets are
subsequently removed. Notwithstanding the fact that the
screws of the drilled-through planks are visible from
above, the wood surface is frequently broken, so that
cracks and projecting splinters form. Moisture penetrates
via the holes and damages the wood, and the weather forms
stains around the holes, which further worsens the already
unattractive aesthetics of the screws. Finally, in long
planks, widened areas arise around the screws, if the wood
and the foundation have different longitudinal coefficients
of expansion.
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A connection system is known from US-PS 2,116,737, by which
boards provided with tongue and groove joints are fixed to
one another and to a foundation. A fastening clamp is used,
whose vertical web has three nails protruding
perpendicularly like claws on the top side, which penetrate
into the plank faces. On the bottom web side, two angled
soles which are bent down perpendicularly are provided,
each approximately half of the web length, which are bent
in opposite directions (left/right) . To maintain the
spacing and fastening on the foundation, a U-shaped rail
which can be screwed onto the foundation is used, which
fixes the clamp via lateral web shoulders, the holes
resting on the legs of the rail. No spaces are provided
between the boards by these known clamps, whereby no air
circulation is possible and no shrinkage is taken into
consideration, so that these clamps are not suitable for
the outdoors.
A connection element is known from US-PS 441,227, which is
usable for producing corner connections of crates. The
clamp is manufactured from a metal strip, in which a
tongue-shaped angled part is cut in a U-shape out of the
strip as a vertical web and bent up perpendicularly. In
addition, three corner tongues are formed as nails in the
plate and in the web, which are hammered into the boards to
be connected on the flat side. These known clamps are not
suitable for a frontally externally invisible connection.
A fastening clamp is known from DE 102 30 797 C2, which is
a double angle composed of two L-profiles and has an
essentially inverted and/or recumbent T-cross-section. The
double wall of the web does provide the advantage of
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increased strength of the web and support of the nails
protruding from the two wall parts by the particular other
wall part, in particular when driving in the clamps and/or
nails. The spacing between the soles is at least double the
plate thickness and can be correspondingly widened by a web
head which can be provided in the outer part of the web,
whereby good ventilation is made possible. Fastening holes
are provided in the two angled soles, via which the clamps
- and thus the planks - are fastenable on the foundation.
In addition, support and spacing beads are introduced in
the angled soles for better ventilation of the foundation,
while downwardly protruding short cutter brackets, which
engage in the support wood in the mounted state, are
provided on the outer edges. These fastening clamps do
represent a very well functioning, robust fastening
element, but in particular due to the double wall of their
middle web, they require a relatively large amount of
material. The use of these clamps, which require a
relatively large amount of material, is put into question
from economic aspects due to the currently rapidly rising
material costs, in particular for stainless steel.
The object of the invention is thus to disclose a fastening
clamp of the above-mentioned species, which can be provided
cost-effectively, while maintaining good handling ability
and ensuring good air circulation between the wood parts,
and a method for the simple, cost-effective production
thereof. This object is achieved by a fastening clamp of
the above-mentioned species having the features of Claim 1
and a method having the features of Claim 10. Advantageous
designs are characterized in the particular dependent
subclaims.
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Accordingly, the fastening clamp according to the invention
comprises a rectangular, preferably square soleplate, on
which two vertical webs are provided centrally in the
transverse extension at a slight distance in the
longitudinal direction adjacent to one another. These webs
are commonly punched out of the soleplate in a U-shape and
bent vertically, i.e., by 90 . Each web carries a
perpendicularly protruding, beak-shaped nail in the
longitudinal middle and associated with its top side, each
in opposing directions. The great advantage is thus
achieved that a minimum of material is used, namely only
one rectangular, preferably square sheet metal plate having
an edge length of approximately 5 cm, for example, from
which webs are cut out in a U-shape alternately in point
symmetry and bent up perpendicularly. No additional
material is thus required for the webs, but rather only
parts and/or bent-up sections of the soleplate. At least
one third to almost half of the material is thus saved in
comparison to clamps having a double-walled web, which is
reflected very significantly in the production costs.
The fastening nails situated in opposing orientation in the
two webs are advantageously implemented and situated so
that each web is preferably provided with only one nail,
and centrally to the longitudinal extension thereof. The
two nails, which protrude freely perpendicularly but in
opposite directions from the two web faces, and also the
clamps as a whole, as explained in greater detail
hereafter, are offset laterally symmetric to a centrally
provided symmetry point, i.e., the clamp sides are each
identical, with offset by 180 of the clamp. Due to this
point symmetry, the clamps do not have to be specially
oriented during installation, so that automation of the
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installation is conceivable, in which the clamps are
automatically supplied and may be installed using an impact
or compressed air pressure device.
According to the invention, the nails are bent out from the
web vertically, i.e., in a perpendicular plane in relation
to the soleplate. If the fastening nail is additionally
curved so it is open downward like a trough or arc, and
tapers from the nail root to the tip, having a small radius
at the tip, the nail shape is noticeably similar to a bird
beak. The nail shape is thus practical, notwithstanding
nature, and is extremely bending resistant over its entire
length.
For additional reinforcement and simultaneous optimized
guiding of the nails upon penetration into the wood, they
may each be provided with a comb-shaped rib on their upper
longitudinal side.
Instead of a rib, however, the nails may also have a notch-
shaped groove in longitudinal central extension for the
same purposes. Such grooves may also each be provided on
the bottom side of the nails. Through the additional
guiding of the nails thus obtained upon penetration into
the wood, the installation is also made easier and twisting
of the fastening clamps is prevented.
It is also particularly advantageous if the webs have a
flattened corrugated profile in the plate longitudinal
direction, whereby the two webs each have opposing bulges.
The nails protrude from the particular flat base of the web
U-profiles, and/or a nail protrudes centrally from each
profiled web. In this way, a greater width and/or thickness
of the web - and thus a greater distance between the planks
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- can be achieved. Thus, at a material thickness of only
approximately 1.5 mm, for example, the width of the web
profile can be 5 mm or significantly more, depending on the
layout of the U-profile.
Notwithstanding the good air circulation thus also achieved
through the web and/or along it, an optimum elasticity of
the clamp is achieved, which has a very positive effect
during shrinkage or swelling actions of the wood, because
the clamp cooperates in some sense in such cases, i.e., may
be elastically compressed or expanded. This is both because
of the two parts of the web and/or the two webs, and also
due to the corresponding web profiles.
Advantageous security against twisting of the installed
clamps is achieved according to the invention in that a
form fit with the foundation is formed via the soleplate,
in that at least one claw-shaped cutter bracket which
protrudes downward is formed and/or bent out of the
soleplate. This cutter bracket may be provided as edge
claws provided protruding on both longitudinal edges of the
soleplate, which are drawn and/or bent at least 0.2 to 2.0
mm, preferably 0.5 mm, than the base bottom side of the
profile recesses of the soleplate. Upon tightening of the
fastening screws, these claw edges or cutter brackets,
which protrude downward from the soleplate, also press into
the support wood.
In order to additionally achieve traction in the direction
of the board upon tightening of the fastening screws, an
angled positioning of the fastening holes can also be
provided by embossing. The screws may thus experience an
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inclination of 5-30 , preferably 10-20 , pointing away from
the vertical webs.
The method for producing the previously described fastening
clamp according to the invention essentially comprises V-
shaped notches, which are offset to one another in the
longitudinal and transverse direction and point in opposite
directions, being introduced into a rectangular, preferably
square plate, having an edge length of approximately 5 cm,
for example, and the corresponding cutouts being formed as
beak-shaped nails essentially perpendicularly and/or by 90
to the soleplate. A U-shaped notch is introduced in each
case in the opposite direction around the nail tongues and
bent down perpendicularly in the same pivot direction as
the nail tongues, so that the nails are finally each
located horizontally and thus parallel above the web cutout
opening. It may be recognized that the fastening clamps
allow a relatively simple punch-technology production in
their basic embodiment.
It is advantageous if, during the production of the
fastening clamp, U-profiles, which are implemented opposite
to one another in the transverse direction and are situated
adjacent to one another in the longitudinal direction, are
first introduced in a downwardly depressed manner into the
sheet metal forming the soleplate. A beak-shaped nail is
then introduced into the flat base of a particular profile
by corresponding punching and bending, after which the U-
shaped cutouts are introduced just outside and parallel to
the outer profile lines and the profile webs are pressed up
correspondingly. Through these U-recesses or profiles,
which are introduced in the first production step and
extend in the transverse direction, on the one hand, the
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bending stiffness of the webs is increased and the web
width and the spacing of the planks to one another are thus
determined. On the other hand, a relatively small support
and/or contact surface with the support wood is achieved by
the particular recess or profile base, it also being
ensured by the introduction of the screw holes into this
profile area that only this relatively small area is
brought into close contact with the support wood. In
addition, it is ensured by the very close configuration of
the screw holes to the particular longitudinal side of the
soleplate implemented as a claw edge that the claw edges,
which are drawn lower than the recess base, claw
correspondingly into the support wood through the
tightening of the screws.
The invention is explained in greater detail hereafter on
the basis of exemplary embodiments with reference to the
drawings.
In the figures:
Figure 1: shows a perspective view of a fastening clamp in
a first embodiment,
Figure 2: shows a top view of the clamp according to Figure
1,
Figure 3: shows a section along line III - III from Figure
2,
Figure 4: shows a section along line IV - IV from Figure 2,
Figure 5: shows a top view similar to Figure 1 of a second
embodiment,
Figure 6: shows a section along line VI - VI from Figure 5,
Figure 7: shows a top view similar to Figures 1 and 5 of a
further embodiment,
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Figure 8: shows a section along line VIII - VIII from
Figure 7,
Figure 9: shows a section along line IX - IX from Figure 7,
and
Figures 10 to 17: show a fastening clamp in various steps
of the production method, each in a top view and
in a frontal view.
It may be seen from Figures 1 through 4 that the fastening
clamp according to the invention comprises a rectangular
soleplate in a first embodiment, in which two vertical webs
2 and 3 are provided in the central zone of the
longitudinal extension adjacent to one another at a short
distance. These vertically oriented U-profiles 4 and 5 each
have a linear profile base 6, which are oriented parallel
to one another in the longitudinal extension and to the
longitudinal edges of the plate, having outwardly opening,
relatively short legs 7 and 8. Leg extensions 9 and 10,
which are essentially parallel to the longitudinal
extension of the soleplate or at least point briefly in
this direction, continue on the outer ends thereof in
relation to the profile base 6, 7. The leg extensions 9 and
of one web are oriented aligned with the profile base 6
of the other web, so that the particular face of the leg
extensions 8 and 9 and the profile base 6 pointing toward
one or the other longitudinal edge 11 or 12 of the
soleplate lie on the same line and thus form linear and
also parallel supports for two planks 13 and 14 to be
connected to one another. Depending on the layout of the
depth of the U-profile 4, 5, the gap or spacing 15 between
the planks can be determined precisely.
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An essentially beak-shaped nail 16 and 17 protrudes
perpendicularly to the web base 6 and simultaneously
parallel to the soleplate 1 from the outer profile base
surface of each web 2, 3, also in opposite extension, of
course. In addition, they are central to the particular web
and simultaneously close to the upper edge thereof. These
nails 16, 17 are designed as longer than the height of the
web, so that the correspondingly tapered nail cutout 18
below the nail occupies the entire height of the web below
the nail and appears to lead further into the plate.
An opening 20 may be recognized on the particular nail side
of the webs 2, 3 in the plate 1, which is obtained by
introducing a U-cutout or U-notch 21, whereby the contour
of the particular web is cut out of the soleplate and
subsequently the web is bent up perpendicularly. A recess
21 may be seen on the particular other side of the webs 2
and 3, which has the same U-profile viewed in longitudinal
section as the particular webs. A hole 23 is introduced
into the soleplate in each of these recesses 21, the
particular outer edge of the recess being terminated
rounded in relation to the hole so that upon introduction
of a screw, the corresponding screw head rests unobstructed
on the base of the recess 22 and allows proper contact
pressure on the support wood.
In addition, it may also be seen from Figure 1 in
particular that the particular nail cutout 18, starting
from the web, is led into the particular recess 22 so that
the hole 23 and/or the corresponding concentric support
surface for the screw head is not interfered with, but the
effective extension of the two lower support surfaces of
the recesses 21 is decreased. Secure fixing on the support
wood 24 is possible through the two screw points, and
simultaneously ventilation underneath over a very large
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area, as is recognizable in particular from Figures 3 and
4.
The longitudinal edges 11 and 12 of the soleplate are each
bent downward and extend somewhat further down than the
lower base surfaces 25 of the recesses 22. They form claw
edges 26, which are longitudinally parallel to one another,
as is recognizable from Figures 3 and 4 in particular. When
the clamps are fastened pressed on and screwed tightly,
having the base surface 25 pressed against the support wood
24, the claw edges 26 are pressed into the support wood 24
like blades, so that twisting, even in the event of
fastening via only one screw, is prevented per se. In
addition, the bending stiffness of the soleplate is
increased by this angle bend.
The second embodiment shown in Figures 5 and 6 differs from
the previously described embodiment according to Figures 1
through 4 solely in that the nails 16 and 17 have a comb-
shaped rib 27 on their upper comb.
When forming the nails of 16, 17, they are provided with a
central buckle, whereby the upper ribs 27 and notch-shaped
grooves 35 on the bottom are formed simultaneously. The
bending stiffness and penetration capability of the
particular nail thus experiences an improvement.
In addition, an essentially L-shaped angle bend 30 is
provided on the particular transverse edge 28 and/or 29,
through which in particular the lateral zones, which are
weakened by the U-opening or notches 20, 21, receive
sufficient bending stiffness.
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Figure 7, 8, and 9 show a fastening clamp similar to that
in the preceding figures as a further embodiment, but here
the nails 16, 17 have a notch-shaped groove 34 on their top
side in central longitudinal extension, which is introduced
by embossing. A groove 35 is simultaneously provided on the
bottom side of the nail.
In addition, it may be seen how an embossing 31 is provided
concentrically to the holes 23 for the fastening screws in
each case, so that the axes 32 of the holes 23 are oriented
at an angle a pointing away from the vertical webs 2, 3.
Figures 10 and 11 show a first section during the chip-free
production of a fastening clamp according to the invention,
the V-shaped nail cutouts 18 and 19 being shown in Figure
10, which are introduced in opposing directions with point
symmetry, while it may be seen from Figure 11 how the nails
16, 17 corresponding to the cutouts 18 and 19 are pressed
perpendicularly downward and implemented as beak-shaped.
Figure 12 illustrates how a profile recess 22 is associated
with each of the nail cutouts 18, 19 and/or was introduced
into the soleplate 1, in addition to a hole 23 in each
case. Figure 13 additionally shows how the U-recesses 22
project from the bottom side of the soleplate 1 and the
nails 16 and 17 protrude from each of them.
Figures 14 and 15 show how, in a further step, a U-notch 21
is associated with each recess 22 and thus every nail 16,
17, and/or is introduced into the plate 1, the base of the
U-notch 21 being situated close to the root of the nail
cutout 18, 19. The parallel legs of the U-notch 21 are
spaced apart from one another enough that they are provided
outside the outer edges of the U-recesses 22, enclosing
them in parallel approximately up to the middle of the
transverse extension of the plate.
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Finally, Figures 16 and 17 show how, in a last step, the U-
cutouts 21 were bent down perpendicularly to the plate
extension and in the same bending direction as the nails
16, 17, whereby the webs 2 and 3 are formed. Simultaneously
or already in the preceding step, the longitudinal edges 11
and 12 were pressed downward and each formed a claw edge
26.
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List of reference numerals
1 soleplate
2 vertical web
3 vertical web
4 U-profile
U-profile
6 profile base
7 profile leg
8 profile leg
9 leg end
leg end
11 longitudinal edge
12 longitudinal edge
13 plank
14 plank
spacing/gap
16 nail
17 nail
18 V-cutout
19 -
(web) punch opening
21 U-cutout
22 recess
23 hole
24 support wood
base surface
26 claw edge
27 rib
28 transverse edge
29 transverse edge
angled bend
31 embossing
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32 axis
33 -
34 upper groove
35 lower groove
