Note: Descriptions are shown in the official language in which they were submitted.
2121216
The present invention rQlates gQnerally to nails
having an expansion region.
More partlcularly, it relates to a nall whlch ha6 an
expansion region formed aS a dlstancQ from a front end face of
the nail and having two bowed expan~lble arms with a free
space therebetween.
Nails of the above mentloned general type are known
in the axt. The German referQnce DE 33 45 331 Al dlsclose~ a
fixing element formed as a nall with an expan6ion region in
the area of its front end face whQreln the Qxpanslon reglon i8
; formed by two outwardly bowed arms extend~ng at a distance
from one another. For anchoring of such a flxlng element the
shank of the fixing element i6 drlven lnto a pre-drllled hole
in masonry or slmllar materlal. When the ~hank ~B driven into
the drilled hole, the expan~ible arms are compressed inwards
,
by the wall of the drilled hole. An increased pressure by the
expansible arms agalnst the wall of the drllled hole can be
; achieved by an in~ert located between the Qxpansible arm6.
2Q After the driving-ln operatlon, the expanslblQ arms of the
ixing eloment are pressed by the plastic and/or resilient
restoring force o the insert against the wall of the drilled
hole. As a rQsult a corre6pondlngly high holding orce is
achieved. However, because of the insQrt the reslstance of
the known nail to being driven in is very high.
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2121216
Accordingly, it 1B an ob~ect o~ the presQnt
invention to provide a nail havlng an expanslon reglon, whlch
avoids the disadvantages of the prior art.
More particularly, it is an object of the pre6ent
invention to provlde a nail havlng an expanslon region, which
on the one hand can be inserted wlthout difficulty lnto a hole
drilled in masonry and on the other hand has high holding
values.
lo In ~eeplng with thesQ ob~ects and wlth others which
- will become apparent hereinafter, one feature of the present
invention resides, briefly 6tated, ln a nail having an
expansion region formed at a distance from a front end of the
~`~ nail and provlded wlth laterally pro~ecting bowed expanslble
arms, wherein a freQ space betweQn the QxpansiblQ arm6 is
formed as a longitudinal channel which starts from a straight
~ shank portion lying before the expansion region as considered
~` -~ in a driving-in direction and extending as far as the front
end face of the nall.
~ When the nail i6 de~igned in accordance with the
present invention, it avoids the disadvantages of the prior
art and providQs for the above mentloned hiqhly advantageous
results.
The laterally projecting expanslblQ arm6 formed by
the longitudinal channel are pressed inward~ by elastic and
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1 resilient deformation a6 the nail is drlven into a drilled
hole, and consequently form a frictional engagement with the
wall of the drilled hole. Due to the resllient and plastic
deformation component of the expan~ion region, high holding
values are achieved. The resilient deformation component also
enables the nail to compensate for any wldenlng of the drllled
hole, for example as a result of cracks forming, without
signi f icant loss of holding values.
¦ The longitudinal channel which starts in the
lo straiyht shan~ section lying before the expan~lon reg~on and
extending as far as the front end face of the nail, provides
a high degree of flexibility at the transltion zones of the
expansion region, which considerably reduce~ the reslstance of
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the nail being driven in, in particular into narrow drilled -
holes. Furthermore, the longitudinal channel whlch 18 open at
~; the front end face of the nail providQs a means whereby the -~
drilling dust present in the drilied hole ls accommodated as
a nail is being driven in. The longitudinal channel extends
as far as the end face and therefore prevents the drilling ;~
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dust from accumulating at the end face of the nail and
hampering or even preventing the operation of driving in of
the nail. The drilling dust fills the longitudinal channel
and as a result increases the holding values, since the
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~ drilling dust additionally acts as a friction-producing agent.
`~;~ 2S In accordance with a further feature of the present ~;
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1 invention, the exp~nsion region can be foxmed by expanding thesh~nk symmetrically by an indenting operation using a wedge,
and at the same time the smooth transitlon~ are molded.
In accordance with a ~till further especially
advantageous feature of the present invention, the outer
surface of the expansible arm has an approximately circular
shape in cross-section, namely with a diameter slightly larger
than that of the shanX. The rounding and the Qxpansion region
thus corresponds approximately to the rounding of the shank
lo and the wall of the drilled hole, wlth the result that a
uniform ~ace-to-face contact against the wall of the drilled
hole is achieved also in the expansion region. The nail
consequently braced in the expansion region against the
drilled hole not only in point-to-point contact but also in
1~ face-to-~ace contact, which produce~ con~iderably better
holding values. BevQling the longitudinal edges of the
expansible arms facilitates bending-in of the expansible arms
as the nail is driven into the drilled hole.
In accordance with another feature of the pre~ent
invention, the longitudinal channel may have a U-shaped cross-
section which is achieved by using a suitable wedge for the
.
indenting process. In the area of the bottom of the channel,
the expansion region therefore has as unlform a cross-section
as is possible. Thls lmparts a hlgh resillence to the bowed
expansible arms.
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1 The nall m~y be provlded wlth a pla~tlc material
coverlng ~tartlng from the nall head and endlng before the
expansion region. This provides additlonal protectlon agaln6t
corrosion in that the covering seals the drilled hole in the
region of the mouth of the drilled hole.
The nall according to the invention, after being
entered in a drilled hole, can only be removed again from it
with extreme difficulty. Therefore, in accordance with a
further development of the invQntion a nail head provided on
lo its upper face has a centQring indentation which is aligned
centrically with re6pect to the center line of the shan~. The
centering indentation enables the nail head to be drilled off
exactly, u~ing a drill bit with a diameter corre6pondlng to
the diameter of the shank. In this manner, for example, a
: ~ 15 board fixed to a wall can be removed wlthout problem6 from the
-~ headless nail, if such a dismantling operation 18 roqulred.
In accordance with ~tlll a further feature of the
~ present invention, the front face of the nail is provided with
X~ a slope to form a nail tip. This improvQs the flow of
drilling dust into the longitudinal channel as the nail is
being driven in.
n accordance with a further embodiment of the
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invention, the expansion region of the nail can be provided
~"i with a longitudinal rib having a triangular cross-section and ~;
arran~ed opposite to the longitudinal channel. The ~
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2i212~
1 longitudinal rib which pro;ect~ beyond the out~r periphery of
the expansion rsgion provlde a further ~ngagement in the
drilled hole in addition to the two expansible arms.
Therefore on the one hand a centering effect ls produced by
the three-point contact and on the other hand a greater
pres6ing action by the expansible arms is achieved. The
longitudinal rib also compensates for tolerances in the
drilled hole due to its triangular shape. In the case of
relatively narrow drilled holes, the longitudinal rib digs
deeper, while in the case o~ wider drilled holes lt digs to a
lesser extent into the wall of the drilled hole. Therefore
constant friction of the expansion region is produced
substantially independently of the diameter of the drilled
hole.
Finally, the longitudinal rib can terminate in a
tapering point at a di6tance from the front end face of the
nail. This facilitates introduction and drlving-in of the
nail-type plug having a longitudinal rib into the drllled
hole.
The novel features which are considered as
characteristic for the invention are set forth in particular
~ in the appended claims. The invention itself, however, both
; as to its construction and its method of operation, together
with additional ob~ects and advantages thereof, Will be best
` 25 understood from the following description of speclfic
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21212~
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1 embodiments when read in connectlon wlth the accompanying
drawings.
FIG. 1 is a slde vlew of a nall having an expan~ion~:
reyion in accordance with the present invention; ~
FIG. 2 is a plan of the front face of the nail of ~ ;.
FIG. l;
FIG. 3 is a view showing a longitudinal sectlon of ,:
~: the inventive nail; ,:~
FIG. 3a lc a view showing a rear ~ide of the front
part of the nail of FIG. l; and
~IG. 4 i6 a view showing a plastic covering of the
nail o~ FIG. 1 in accordance with the present lnvention.
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A nail in accordance with the present invention
6hown in FIG. 1 is identified as a whole wlth refQrence
numeral 1. The nail has a shank 2 with an expansion region 3,
and a nail head 4. The nail has an end face 5. The expansion
region 3 i8 set back ~lightly from the front end face 5 80
that a straight shank portion 6 i8 provlded between the end
face 5 and the expansion region 3. Another longer ~tralght
shank portion 7 is located between the expansion region 3 and
lo the nail head 4. The nail 1 can be made from metal.
In the expansion region 3 the nail i8 provided with
a longitudinal channel identlfied wlth reference numeral 8.
~;~ The channel can be formsd by an indenting proce6s with use of
a wedge. The longitudlnal channel 8 can have a U-shaped
cross-section as can be more clearly seen from FIG. 2. The
longitudinal channel 8 is bounded by lateral expansible arims
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~ 9 and 10. The arms bow outwards and project from the shank 2.
,
~-~ The longitudinal ohannel 8 is open at the front end S, and the ~'
end face 5 is provided with a slope 11. Therefore, drilling
- ~ 20 dust can be guided more efficiently into the longltudinal
channel ~ as the nail is being driven in.
The U-~hape of the longitudinal channel 8 is clearly
shown in FIG. 2. In the region of the bottom of the channel
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there is a uniform wall~thickness for the expan~on region 3
2so that a high resilience of the outwardly~ bowed expansible
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1 arms 9 and lo i~ providQd. The longitudinal edgeG o f the
expansiblQ arms 9 and 10 are beveled in order to promote
inward bending and positioning of the arms aga1nst the wall of
the drilled hole.
FIG. 3 6hows a nail of FIG. 1 ln a longitudinal
section turned by 90~. The slopQ 11 at the front end face 5
of the nail runs from the open sldQ of the longitudinal
channel 8 at an acute angle to the bottom 12 of the
longitudinal channel.
As shown in FIG. 4, the nail 1 i~ provlded with a
plastic material covering 13 in the area of the nail head 4
and the shank 2. The plastic mater~al covering 13 terminates
flush with the shank 2 before the expansion region 3.
~he nail head 4 has a top face provided with a
centering indentation 14. The lndentation 14 1~ allgned
centrally with respect to the longitudinal axis of the shan~
~:~; 2.
The nail 1 further has a longitudinal rib 15 which
is provided at the expansion region 3 as shown in FIGS. 2, 3
-`~ 20 and 3a. The longitudinal rib 15 has a triangular profiIe and
is located opposite to the longitudinal channel 8. The
longitudinal rib 15 ends at a distance from the front end face
5 of the nail and has a tapering point 16 in order to ease
insertion and to facilitate driving of the nail 1 into a
drilled hole.
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~ 2121216
1 It will be understood that each of the element6
de~cribed above, or two or more together, may also find a
useful application in other types of con~tructions differing
from the types described above.
While the lnvention has been illustrated and
described as e~bodied in a-nail with an expansion region, it
is not intended to be limlted to the details shown, since
various modifications and structural changes may be made
without departing in any way from the splrlt of the present
invention.
Without further analysis, the foregoing will ~o
fully reveal the gist of the present lnvention that others
can, by applylng current knowledge, readlly adapt lt for
various applicatlons without omitting features that, from the
standpoint of prior art, falrly constltute essentlal
~; characteristics of the generic or speclSlc aspQcts of this
invention.
~ What is claimed a6 new and desired to be protected
-~ by Letters Patent is sQt forth in the appended claims.
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