Note: Descriptions are shown in the official language in which they were submitted.
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CONNECTING ELEMENT FOR CONNECTING AT LEAST TWO WOODEN
CONSTRUCTION PARTS AND A JOINT PLATE
The invention relates to a connecting element with a substantially rod-like
shank for joining at least
two wooden structural members and at least one joint plate, especially of the
type that can be
inserted into one or more slot(s) of the wooden structural members, and
preferably made of metal.
In truss or frame constructions, the wooden structural members used are
usually connected by joint
plates made of metal. The joint plates are inserted in central slots at the
ends of the wooden
structural members. In the wooden structural members and the joint plates
there are provided holes
in a coinciding pattern, in which holes there are usually inserted plain
dowels. These plain metal
dowels fix the joint plate in the wooden structural member in question. To
ensure that the plain dowel
can transmit the forces specified according to standards between the wooden
structural members and
the joint plate, and that a joint which is as rigid as possible and prevents
mutual displacement can
be formed, the holes in both the wooden structural members and in the joint
plate must be matched
relatively closely and fittingly to each other.
Since two different materials are used here, namely wood on the one hand and
the metal joint plate
on the other hand, special problems arise in making the holes. The usual
practice heretofore -- in
order to be able to meet drilling tolerances -- has been to drill the holes in
the wooden structural
members first. The joint plate is then inserted into the slot of the wooden
structural members,
whereupon the holes are made in the joint plate, so that the already completed
holes in the wooden
structural members form a kind of hole gauge, as it were. The holes in the
joint plate are now made
with a suitable drill, and the plain dowels for mutually joining the wooden
structural members and joint
plate are hammered in. On the one hand this working principle is very
laborious, and on the other
hand a rigid and load-bearing joint cannot be achieved therewith, since the
accuracy of fit is not
optimal.
In another known working principle, the holes are made first of all in the
joint plate. This joint plate
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is then used as a template for drilling the holes in the wooden structural
members. Since in such a
case the ultimate position of the joint plate is axially offset relative to
the drilling process,
corresponding inaccuracies can be introduced here also, and so dimensional
tolerances may not
necessarily be met. Furthermore, this working principle is also very
cumbersome and time-consuming.
According to yet another known method (German Patent C-43 15 101), the joint
plate is first inserted
in the appropriate slot in the wooden structural member. While this condition
of insertion in correct
position is maintained, the holes are made through the wooden structural
members and the joint plate
by means of a drilling jig. For this purpose there is used a kind of variable-
speed drill, in order to be
able to cope with the different conditions of drilling in wood and in metal.
After the hole has been
completed, the plain dowels can be appropriately hammered in.
A special holder for the drilling jig is needed even in such a known
embodiment, since it is also
necessary to ensure that the joint plate inserted into an appropriate slot in
the wooden structural
member cannot shift.
Precisely for working on the construction site itself does such an arrangement
cause problems,
because the use of particularly large and bulky jigs on the building is
associated with cumbersome
handling. Furthermore, accessibility for such a drilling jig is not available
everywhere.
From German Patent Application A-41 24 553 there is also known a connector for
covered beam
joints, with the purpose of avoiding exact measuring and drilling work. Nails
are hammered in to join
the wooden structural member and the joint plate, without making holes
beforehand. For this purpose,
however, the joint plate must have a very special construction, in order to
permit it to be penetrated
at all by nails. Thus it must be ensured that the joint plate region through
which nails will be driven
comprises thin sheet metal. Providing this special region introduces the risk
that the nails will bend
or that cracking will occur, since such joint plates are usually inserted at
the end faces of wooden
structural members.
The object of the present invention is therefore to provide a connecting
element of the type cited in
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the introduction, with which wooden structural members and joint plates can be
joined with accurate fit and, in fact, with simple handling regardless of the
type of
wooden structural members and joint plates.
According to the present invention, there is provided an assembly of at least
two
wooden structural members, comprising:
said at least two wooden structural members confronting each
other, at least one wooden structural member having a slot that opens toward
another woo den structural member,
a joint plate extending from said other wooden structural member
into said slot,
a connecting element having a shaft disposed through said joint
plate and comprising at one end a boring portion for penetrating said at least
one wooden structural member on both sides of said joint plate, and
means for preventing axial displacement of said connecting
element within said at least one member, the means for preventing axial
displacement being located on the shaft.
The above object is preferably thus achieved in that the rod-like shank is
provided at least at one of its ends with a boring part and at its other end
with a
tool drive for rotary motion, the diameter of the shank corresponding at least
approximately to the boring diameter of the boring part at least over one or
more
partial regions of its length, and in that means for securing against axial
displacement in the inserted condition are formed on the shank.
By means of the invention, the hole at least in the joint plate or if
necessary both
in the joint plate and in the wooden structural member can be made in one
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working step, specifically by the rod-like connecting element, which
ultimately
brings about mutual connection of joint plate and wooden structural member in
this hole. Since the connecting element therefore makes the hole in the joint
plate and simultaneously forms the connection between these two parts in one
working operation, the holes in the joint plate and in the wooden structural
member always match with accurate fit. Thereby there is achieved an exact and
displacement-proof joint between the joint plate and the wooden structural
member. In this respect it is inherently immaterial whether, in the case of
arrangement of a plurality of connecting elements to be inserted parallel to
each
other, these are now oriented exactly parallel to each other or include an
acute
angle therebetween. Each connecting element in itself establishes between the
wooden structural members and the joint plate an optimal fastening with exact
fit
and layout.
The connecting element is held interlockingly andlor frictionally in the hole
of the
joint pate and/or in the wooden structural member in such a way that it is
secured against axial displacement. Precisely by virtue of the chips produced
during the drilling process, an additional intimate connection is created
between
the connecting element and the joint plate or the wooden structural member, so
that the mere action of driving in the connecting element can secure it
interlockingly and/or frictionally against axial displacement. Of course,
other
additional means can certainly also be used to bring about an interlocking
andlor
frictional and captive holding relationship.
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By the use of the connecting element according to the invention, it is also
possible to push into one
another or place against one another a wooden structural member with
predriiled holes and a joint
plate, after which a connecting element is introduced into the predrilled hole
in the wooden structural
member and thereafter the hole in the joint plate itself is made. In this way
it is possible to use holes
already driiled in the factory as a kind of gauge for subsequently drilling
through the joint plate. Even
in such a sequence of the method, the hole in the joint plate itself is made
by the connecting element,
which simultaneously brings about mutual connection of the wooden structural
member and the joint
plate. In this case also an exact fit is achieved between the holes in the
wooden structural member
and in the joint plate, and so the connecting element joins the wooden
structural member and the joint
plate to one another in firmly seated relationship.
The connecting element does not even have to pass completely through the
wooden structural
member. The setting process for the connecting element can therefore be ended
before a through
hole has been made. Thereby the type of the mutual joint is not even visible
on one side of a wooden
structural member. In this way the joint can be concealed or kept invisible on
one side of the wooden
structural member, thus satisfying esthetic principles. From the strength
viewpoint, a through hole is
not necessary for the joint, since it would be sufficient for the connecting
element to penetrate at least
a certain distance into the wooden structural member starting from both sides
of a joint plate.
By these features according to the invention there is created a connecting
element which is
particularly suitable for this very special purpose. Heretofore, screws have
already been used for
fastening sheet-metal connectors or the like, which are disposed on the
surface of wooden structural
members. In wood construction in itself, and especially in the mutual
fastening of wooden structural
members and joint plates, there has been no use heretofore of self-drilling
connecting elements.
Precisely in the embodiment specifically under consideration here, however,
the construction of a
connecting element as a kind of rod-like shank with an appropriate boring part
represents a
substantial advance. The necessary hole can be made in one working operation
with such a
connecting element. In addition, the connecting element disposed in this hole
to connect the joint
plate and the wooden structural member is then also available immediately.
Moreover, a mutual
fixation which is exact and resistant to transverse displacement is possible
with such a connecting
element. A proper hole can be made optimally both in the wooden structural
member and in the metal
joint plate by means of an appropriately shaped boring part.
AMENDED SHEET
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There are known a series of boring screws (from German Patent Application DE A
3828446, among
others) which have a boring tip and a shank with a thread. In such boring
screws there is always provided
an appropriately long thread, and it is always ensured that the boring
diameter is larger than the minor
d+ameter of the shank in the threaded region. For the purpose intended here,
however, boring screws are
very generally unsuitable, since feed corresponding to the thread pitch would
already be present in the
boring process. It is precisely such a result, however, that is inconceivable
for boring through relatively
thick joint plates.
AMENDED SHEET
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In a further proposal, one or more flute(s) is or are formed on the boring
part and possibly on a
portion of the rod-like shank adjoining the boring part. By virtue of such
flutes the possibility is created
that worked-off material produced during the drilling process can be
appropriately transported and
received. In this respect there is no need for the chips to be conveyed to the
open, but instead it is
sufficient for the produced chips to be received in compacted form in the
flutes. It is then also
immaterial whether one or the other metal chip becomes embedded in the hole
wall in the wooden
structural member, since this in no way compromises the ultimate fit. The
connecting element which
itself makes the hole ultimately remains, in fact, in the said hole.
In one alternative embodiment it is proposed that a portion with diameter
smaller than that of the
boring part directly adjoin the boring part. Thereby a larger receiving
capacity for the drill chips is
created in the region directly adjoining the boring part.
In a special embodiment of the invention it is provided that a further boring
portion with boring
diameter larger than that of the first boring part be formed on the rod-like
shank offset at an axial
distance from the boring part. In this way, completion of the hole and the
quantity of chips produced
can be divided between two drilling processes performed consecutively in the
same working
operation. This is advantageous precisely in the case of correspondingly
thicker connecting elements.
To create a particularly large receiving capacity for the drill chips
produced, it is proposed that one
or more flute(s) be extended over a large part of the length or over the
entire length of the rod-like
shank.
In a further alternative embodiment, a thread or a thread-like structure is
provided at least over a
partial region of the length of the rod-like shank. Additional particular
security against axial
displacement of the connecting element is achieved thereby, and so the
connecting element cannot
be loosened once finally set, even in the event of shrinkage in the region of
the wooden structural
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In other possible embodiments in this context, it is proposed that a roughened
surface, knurling or
the like be provided or that raised structures or depressions be formed at
least over a partial region
of the length of the rod-like shank. In this way also additional security
against twisting and
displacement of the connecting element can be achieved, thus preventing
extraction of the connecting
element from the finished hole after final setting.
To close off the beginning of the hole optimally and to achieve appropriate
sealing of the wood in this
region, it is proposed that the end of the rod-like shank remote from the
boring part have flaring
frustoconical shape. Such a flaring frustoconical shape naturally can also be
used in order to increase
the torque appropriately. In this way the further driving-in process could be
stopped in torque-
dependent manner.
A preferred embodiment provides that one or more flute(s) is or are formed on
the portion of the rod-
like shank which follows the portion of reduced diameter and which is adapted
at least approximately
to the boring diameter. Thus a larger annulus for receiving chips is created
not only directly following
the boring part, but thereadjoining there are also provided flutes which can
receive drilled material,
even though the flutes do not already have to extend directly from the boring
part itself. Thereby it
is also specially ensured that the torque on the connecting element to be
screwed in is not
excessively increased by correspondingly large production of drill chips.
For the special type of application of the connecting element according to the
invention, it is
particularly advantageous for the tool drive to be formed as an internal
drive. Not only a specially
shaped internal drive but also a kind of screw slot can be regarded as one
kind of such an internal
drive. This ensures that even the driven end of the connecting element can be
driven in sufficiently
by simple means until it is below the surface of the wooden structural member.
Within the scope of the invention, however, it is also possible for the tool
drive to be formed as an
external drive, in which case an external hexagon, for example, can be
provided. Since this external
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drive must have appropriately small cross section, especially if the
connecting element is to be
countersunk, the possibility that external drives can be used depends on the
torque to be transmitted.
In a special embodiment of the connecting element, and especially when the
connecting element
must have appropriately larger diameter, it is provided that the further
boring portion with boring
diameter larger than that of the first boring part is followed on the rod-like
shank by a substantially
cylindrical portion with diameter slightly smaller than that of the further
boring portion. Although this
further boring portion makes a slightly larger hole, the rod-like shank
following it is held fixedly with
excellent fit both in the joint plate and in the wooden structural member.
Nevertheless, it is ensured
that the torque will be increased excessively in the event of zero clearance.
In this way the torque
required to achieve drilling and to advance the connecting element is
appropriately balanced with the
necessary fit between the holes.
In one embodiment of the connecting element, one or more helical flute(s) is
or are provided. In this
case the drill chips produced are transported in the helical flutes toward the
driven end of the
connecting element, for practical purposes in the same manner as with a twist
drill. Thereby it is
ensured that the flutes are for practical purposes filled completely with
drill chips until the connecting
element has been finally set, and so there is obtained a connecting element
with substantially
continuously cylindrical form and full surface contact with the wall of the
hole.
Within the scope of the invention, however, it is also conceivable for one or
more flute(s) to be
disposed parallel to the axis. In such flutes, the transport effect of the
chips for practical purposes no
longer exists, even if the connecting element is being turned, and so flutes
in such an arrangement
are filled in axial direction exclusively by drill chips which are being
pushed back in axial direction.
Further features according to the invention and special advantages will be
explained in more detail
in the description hereinafter with reference to the drawings, wherein:
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Fig. 1 shows an exploded diagram of a joint between two wooden structural
members via a joint
plate, the connecting element to be inserted also being illustrated;
Fig. 2 shows an embodiment of a joint between wooden structural members with a
special kind of
joint plate;
Fig. 3 shows a view of a special connecting element according to the diagram
in Fig. 1;
Fig. 4 to Fig. 9 show several alternative embodiments of joints between wooden
structural members
and a joint plate, different constructions of connecting elements also being
inserted in some
cases;
Fig. 10 and Fig. 11 show two embodiments for joining two wooden structural
members adjoining one
another at their end faces with appropriately shaped joint plates.
The present invention therefore relates to a method and to an appropriate
connecting element 1 for
joining at least two wooden structural members 2 and 3. In the diagram
according to Fig. 1, there is
used for this purpose a joint plate 4, which is equipped with a foot part 5
disposed in transverse
relationship thereto. Foot part 5 is provided with appropriate holes 6, in
which screws 7 can be
inserted. Joint plate 4 is therefore screwed abuttingly onto wooden structural
member 2 via foot part
5. The end face, or in other words the free end of wooden structural member 3
is now brought up
against wooden structural member 2. In wooden structural member 3 there is
formed a slot 8, into
which joint plate 4 can be pushed. In principle, it would also be conceivable
to dispose joint plate 4
such that it adjoins the end of wooden structural member 3 on the outside
thereof, but for reasons
of better force transmission and force distribution an approximately central
disposition of joint plate
4 in a slot 8 of wooden structural member 3 is advantageous. Once joint plate
4 has been pushed
into slot 8, wooden structural members 2 and 3 are disposed in specified
position relative to each
other, and so now joint plate 4 and wooden structural member 3 can be fastened
together. For this
purpose there are used connecting elements 1, which are inserted into the
solid material of wooden
structural member 3 and of joint plate 4. Connecting element 1 itself makes
the respective hole 9 in
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joint plate 4 and if necessary in wooden structural member 3 also, and
thereupon functions directly
as the connecting element which remains in self-made hole 9.
In this context, it is also possible that such a connecting element 1 does not
extend completely
through wooden structural member 3, or in other words its end does not
penetrate completely through
wooden structural member 3. This can be advantageous for esthetic reasons, but
is also practical if,
for example, the connecting element and the method according to the invention
are being used in
humid rooms, since boring part 11 of connecting element 1 should not be
exposed, because it is
made, for example, of carbon steel.
According to a slightly different method, it is also possible to provide
wooden structural member 3
with holes already drilled in the factory, in which case joint plate 4, which
is not yet provided with
holes, is inserted in slot 8. Predrilled holes 9 then for practical purposes
form a kind of drilling gauge,
into which connecting elements I are inserted. Connecting elements 1 would
then have to make only
the hole in joint plate 4, immediately after which they are inserted as
appropriate connecting elements
between joint plate 4 and wooden structural member 3.
By the very use of a self-drilling connecting element, there can be achieved,
in joining at least two
wooden structural members via a joint plate, a substantial improvement, which
not only is manifested
in simpler and faster handling but also ensures that each connecting element
used is inserted with
exact fit, thus creating optimal force transmission without the possibility of
transverse displacement.
By special design of the connecting element, the diameter of the hole to be
made can be matched
exactly to the diameter of the connecting element, and so an optimal fit is
made possible.
In the embodiments according to Figs. 1 and 3, connecting element 1 to be used
according to the
invention comprises substantially a rod-like shank 10, which is provided at
one of its ends with a
boring part 11 and at its other end with a tool drive 12 in the form of an
internal drive. Diameter D2
of shank 10 is fashioned over at least one or more partial regions of its
length to correspond at least
approximately to boring diameter Dl of boring part 11 and, while connecting
element 1 is in final
position, must be present in the region of joint plate 4 and in the nearest
possible regions of wooden
structural member 3 which follow it. An appropriate fit between completed hole
9 and shank 10 must
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be achieved at least where the greatest shear forces occur in the joint
between joint plate 4 and
wooden structural member 3.
Appropriate flutes are of course provided on boring part 11 itself. In
connecting element 1 according
to the invention, however, one or more flutes 13 is or are also formed, at
least in the embodiment
according to Figs. 1 and 3, on the region of shank 10 adjoining boring part
11. In the illustrated
embodiment these flutes 13 are helical, which is advantageous in particular as
regards material
transport for the worked-off drill chips. It is certainly not intended that
the worked-off material
absolutely be transported into the open, but instead that it be received under
certain circumstances
in appropriately compacted form in the hole itself or in appropriate recesses
of connecting element
1. In this context, it is also possible for one or more flutes to be disposed
parallel to the axis. Such
flutes are then not filled constantly by material being pushed back by the
turning process during
drilling, but they receive the chips adhering to the hole wall or are filled
by chips being pushed back
axially.
It is expedient for flutes 13 to extend over a large part of the length or
over the entire length of rod-
like shank 10, and certainly at least as far as this has diameter D2. Of
course, the flutes can also be
made appropriately shorter depending on the chips produced by the drilling
process.
.In the embodiment according to Figs. 1 and 3, it is further provided that a
portion 14 with diameter
D3 smaller than that of boring part 11 directly adjoins boring part 11. By
this construction there is
created an additional annular space for receiving drill chips, directly
following boring part 11. Portion
14 need only have a diameter D3 capable of transmitting the torque for the
drilling process. As
regards transmission of forces between joint plate 4 and wooden structural
member 3, however, this
portion 14 has no further influence, since it is disposed far outside joint
plate 4 iriserted in slot 8.
By virtue of portion 14, which has smaller diameter and follows boring part
11, the portion of rod-like
shank 10 having diameter D2 begins at an appropriate distance from boring part
11. Boring diameter
D1 of boring part 11 is matched approximately to diameter D2 of shank 10,
especially for achieving
an optimum fit. In the illustrated embodiment, the portion of shank 10 with
diameter D2 is provided
with helical flutes 13 over its entire length. It is precisely with such an
embodiment that a relatively
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large space for receiving drill chips can be created by the annular space
provided in the region of
portion 14 and by flutes 13 which then adjoin it.
At the end of connecting element 1 remote from boring part 11 there is formed
a thread 15, which
for practical purposes bites into completed hole 9 during the last turning
movements of the drilling
process. This thread 15 ensures that connecting element 1 is secured axially
and therefore cannot
escape spontaneously from completed hole 9 if it is not exposed directly to
sufficient shear forces or
if shrinkage develops in the region of wooden structural member 3. Other
thread-like structures could
also be provided instead of thread 15, in which case it is also conceivable to
provide a plurality of
circular circumferential ribs which are disposed parallel to each other and
which in cross section, for
example, have a sawtooth profile. The intention here is simply to create an
additional possibility of
holding connecting element 1 securely against displacement in its axial
direction.
A further alternative embodiment in this context could be to provide a
roughened surface, knurling
or the like, or else to form other raised structures or depressions. In all of
these embodiments,
spontaneous twisting and spontaneous axial displacement of the connecting
element will be
prevented.
In the embodiment according to Fig. 1 and other illustrated embodiments, there
is illustrated an
appropriate slot 8, which passes completely through the entire height or
thickness of wooden
structural member 3. An embodiment is also conceivable, of course, in which
this slot 8, viewed in
its plane, does not pass completely through but for practical purposes is
machined as a mortise with
rectangular cross section at the end face of wooden structural member 3, into
which mortise joint
plate 4 is inserted. In this case, all that can be seen of wooden structural
member 3 after connecting
element 1 has been inserted is that a joint has been made here with a joint
plate, specifically because
slot 8 and thus also the arrangement of joint plate 4 are no longer visible
externally.
In the construction illustrated in Fig. 2, wooden structural members 17, 18
and 19 are joined to each
other by substantially vee-shaped joint plates 4. In this way a kind of wooden
truss can be made, in
which joint plates 4 and connecting elements 1 are used for mutual joining. In
this case also there
are formed, at the ends of wooden structural members 18 and 19, slots 8 into
which joint plates 4 can
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be inserted. Wooden structural member 17 is also provided with slots 8, into
which there is joined a
kind of web part of the two joint plates 4 aligned at an acute angle to one
another. By direct insertion
of connecting elements 1, holes 9 are made both in wooden structural members
17, 18, 19 and in
joint plates 4, thus simultaneously forming a joint with accurate fit. In such
an arrangement also it is
of course possible to provide that holes 9 in wooden structural members 17, 18
and 19 are already
made in the factory, and so only the holes in joint plates 4 then have to be
made by the connecting
elements according to the invention. In such an embodiment, boring part 11 of
connecting element
1 according to the invention certainly has to pass through two joint plates 4
disposed at a distance
from one another. It is therefore particularly important for the connecting
elements and the holes to
be exactly matched to each other, which can be achieved only by precisely the
present invention, or
in other words when the connecting element itself drills the hole in which it
will ensure force
transmission by its proper fit.
Fig. 4 shows for practical purposes a section through a configuration as it
would exist in the finished
joint of the embodiment according to Fig. 1. It is therefore clear here that
the length of the entire
connecting element 1 must be equal to or shorter than the thickness of wooden
structural member
3, measured in axial direction of connecting element 1. It is also clear that,
because of the reduced
diameter of portion 14 and because of flutes 13 formed additionally in shank
10, a relatively large
space for receiving the drill chips is created. If connecting elements 1 were
to be shorter, it would
have to be ensured that boring part 11 has already drilled through joint plate
4 before thread 15
disposed at the rear end of connecting element 1 enters the hole. Because of
the very small distance
advanced during drilling in joint plate 4, the engagement necessary for
retention in the region of
thread 15 would be destroyed, since the wood in the region of the hole wall
would be completely
reamed out.
The configuration according to Fig. 5 shows that there is provided, offset at
an axial distance from
boring part 11, a further boring portion 20 with a boring diameter larger than
that of first boring part
11. Thereby the hole to be made can be bored out in stages. This design is
useful precisely when
a connecting element with larger diameter D4 is to be inserted. In this case,
therefore, further boring
portion 20 is followed by a rod-like shank 10 with diameter D4, and diameter
D4 of shank 10 can be
made slightly smaller than the boring diameter of further boring portion 20.
Such a feature ensures
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that hole friction between connecting element 1 and hole 9 is not too great,
and so the boring process
can be completed as far as final setting of the connecting element without
excessive torque increase.
Within the scope of the invention, it is conceivable to provide more than two
stages of different
diameters of boring portions, depending on the corresponding diameter D4 of
shank 10.
From Figs. 6 to 8 it is evident that the most diverse alternative embodiments
of connecting elements
can absolutely be used, and that portions 14 of reduced diameter, flutes 13 or
other embodiments
can be combined with each other in appropriate ways. In the embodiments
according to figs. 6 to 8
it is additionally provided that a flaring frustoconical portion 21 is formed
on the end of shank 10
remote from boring part 11. In this way the hole wall is further
correspondingly compacted in the end
region, thus preventing a frayed pattern of chips from forming at the surface
of wooden structural
member 3. In these arrangements also there is provided a tool drive 12 in the
form of an internal
drive, which can also be formed as a kind of screwdriver slot.
In the embodiment according to Fig. 9 there is provided a tool drive 16 in the
form of an external
drive, in which case it must be ensured, of course, that an appropriate torque
can be transmitted and
also that the free end containing tool drive 16 can be countersunk in wooden
structural member 3.
Thus appropriate adaptation to a tool also has to be achieved.
Fig. 9 further shows an embodiment of a connecting element 1 provided at the
surface with one or
more raised structures 22. It is conceivable in this case that such raised
structures 22 will eventually
be disposed in the region of the wooden structural member or in the region of
joint plate 4 once
connecting element 1 has been finally set. Security against twisting and
displacement is also achieved
with such an arrangement.
The embodiments according to Figs. 10 and 11 demonstrate that not only wooden
structural members
brought up against each other at right angles or wooden structural members
brought up against each
other in the manner of a truss, but also wooden structural members 23, 24
brought up against each
other abuttingly with their end faces can be joined together with a joint
plate 4. In this case there are
provided joint plates 4 projecting in two opposite directions from a
transverse plate 25 and extending
into corresponding slots at the ends of wooden structural members 23, 24. As a
result, it is also
CA 02293409 1999-12-07
WO 98/56998 PCT/EP98/03266
-14-
possible, as can be inferred from Fig. 11, that the two wooden structural
members 23, 24 can adjoin
one another at an obtuse angle, thus also achieving the possibility that joint
plates 4 can be disposed
at an appropriate angle to one another or to intermediate plate 25. In this
case also, the joint is again
made by connecting elements 1 according to the invention, which bore through
wooden structural
members 23, 24 and joint plates 4 and then themselves complete the joint.
In the foregoing description, reference was made to a tool drive 12 or 16 in
the form of an internal
or external drive. Within the scope of the invention it would be entirely
conceivable to equip
connecting element 1 according to the invention with a head in the same manner
as for a screw,
which head would then be provided with an appropriate internal or external
drive. In such a
construction, however, it must be kept in mind that the connecting element may
well be almost
impossible to countersink completely at its driven end, since the head
actually extends
correspondingly beyond the diameter of shank 10.
Connecting element 1 can also be made of, for example, stainless material, in
which case the boring
portion is made hardenable for the necessary boring process. It is also
possible to weld on a boring
part or to insert an appropriate boring tip of, for example, carbon steel.
It was also assumed in the foregoing description that a joint plate of metal
such as steel or aluminum
is used. If the material were sufficiently strong, it would also be
conceivable to use a joint plate of
plastic, in which case the method according to the invention and the
connecting element can of
course also be used for such a construction.
,1
