STRUCTURE OF AN ANTI-BURGLAR SCREW BOLT

STRUCTURE D'UN BOULON A FILETAGE DE VIS ANTI-CAMBRIOLEUR

English Abstract

An anti-burglar screw bolt includes a bolt, first and second pads, and a nut. The bolt head is hexagonal, and consists of six sections of same shape each having a slope on a lower side and abutting a lower end of adjacent section at a higher end. Each of the pads has slopes like those of the bolt head; each of the pads has radial pointed bars formed on other side, and gaps on lateral side for a tool to engage, which is especially designed for undoing the bolt. The nut is hexagonal, and has slopes like those of the bolt head. The bolt is passed through the first pad, workpieces, and the second pad in sequence, and is screwed into the nut to fasten the workpieces together with the radial pointed bars being driven into surfaces of the workpieces. The bolt combination can't become loose because the pads abut both the bolt and the nut to hinder reverse rotation of the bolt that will undo the bolt.

French Abstract

Un boulon à filetage de vis anticambrioleur comprend un boulon, un premier et un second segment et un écrou. La tête du boulon est hexagonale et consiste en six sections de forme identique ayant une pente sur un côté inférieur et étant attenantes à une extrémité inférieure de la section adjacente à une extrémité plus haute. Chacun des segments a des pentes comme celles de la tête du boulon, chacun des segments a des barres radiales pointées formées sur l'autre côté et des espaces sur le côté latéral afin qu'un outil spécialement conçu pour défaire le boulon puisse s'y engager. L'écrou est hexagonal et a des pentes comme celles de la tête du boulon. Le boulon est inséré au travers du premier segment, des pièces à travailler et du second segment en séquence, puis il est vissé dans l'écrou pour fixer ensemble les pièces à travailler, les barres radiales pointées étant poussées dans les surfaces des pièces à travailler. Le couplage du boulon ne peut pas devenir lâche, car les segments sont attenants à la fois au boulon et à l'écrou pour empêcher la rotation inverse du boulon qui défera le boulon.

Claims

WHAT IS CLAIMED IS:
1. An improvement on structure of an anti-burglar screw bolt, comprising:
a bolt; a head of the bolt having a hexagonal shape, and consisting of six
sections of a same shape; each of the six sections including a wedge-shaped
slope on a bottom side, and abutting a lower end of an adjacent section at a
higher end thereof so that a stopping edge is formed on the higher end
thereof;
a first pad and a second pad; each of the pads having a central through
hole and six sections of a same shape around the through hole; each of the six
sections of each of the pads having a sloping surface, and abutting a lower
end
of an adjacent section at a higher end thereof so that an engaging edge is
formed on the higher end thereof; each of the pads having radial pointed
insertion bars formed on other side at spaced apart positions;
a nut; the nut having a hexagonal shape, and six sections of a same
shape; each of the six sections of the nut having a wedge-shaped slope on one
side thereof, and abutting a lower end of an adjacent section at a higher end
thereof so that an engaging edge is formed on the higher end thereof;
the bolt being passed through the first pad, workpieces, and the second
pad in sequence, and being screwed into the nut to fasten the workpieces
together with the radial pointed insertion bars being driven into surfaces of
the
workpieces;
wherein each of the radial pointed insertion bars has a slope on one side,
and a straight side on other side thereof; the slopes of the radial pointed
insertion bars facing a same direction as corresponding sloping surfaces
formed
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on opposite side of the pads so as to help the radial pointed insertion bars
to be
driven into the surfaces of workpieces with increased ease.
2. The improvement on structure of an anti-burglar screw bolt as claimed in
claim 1, wherein at least one of the pads is round, and has gaps formed on
lateral portions of at least one pair of opposing sections thereof.
3. The improvement on structure of an anti-burglar screw bolt as claimed in
claim 1, wherein at least one of the pads is round, and has gaps formed on
lateral portions of at least one pair of opposing sections thereof, and rest
of the
pads is made to have a hexagonal shape.
4. The improvement on structure of an anti-burglar screw bolt as claimed in
any
one of claims 1 to 3, wherein the radial pointed insertion bars are
equidistantly
positioned.
5. The improvement on structure of an anti-burglar screw bolt as claimed in
any
one of claims 1 to 5, wherein the sloping surfaces of the pads further ascend
gradually from outward edges towards inward edges thereof so that the pointed
insertion bars of the pads have outward ends being taller than inward ends.
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Description

CA 02438817 2003-08-28
STRUCTURE OF AN ANTI-BURGLAR SCREW BOLT
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to an anti-burglar screw bolt, more
particularly an anti-burglar screw bolt, which can't become loose after
long period of use on a workpiece subject to vibration, and which can't
be turned loose without tools especially designed to loosen it.
2. Brief Description of the Prior Art
Bolts are used as a popular means for fixing various parts of public
constructions in position, e.g. fences on two sides of roads, road signs,
and train rails. Bolts have to be particularly loosening-resistant to be
used to fix train rails in position because train rails are subject to
vibration and because accidents are likely to happen if the bolts fixing
the rails become loose. And, in light of the fact that public properties
such as road signs have become the targets of burglars, several
improvements have been made on bolts so that the bolts can help prevent
objects from being stolen besides fixing the objects in position. Bolts are
also a major means for joining various parts of machines, and have to be
loosening-resistant so that the machine parts won't become loose after
long period of worlcii-lg.
Referring to Fig. 1, a conventional screw bolt I is made
loosening-resistant by means of first passing it tlirough a pad 11, a
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CA 02438817 2003-08-28
workpiece, and a stationary object (not numbered), and then screwing it
through two nuts 12, and 13. The screw bolt 1 is less likely to turn
relative to the nuts 12, 13 to become loose when the workpiece is
vibrating due to the friction of the nuts 12, 13 against each other as well
as the fact that rotational movement of one nut 12 (13) would be
hindered by the other 13 (12). However, the screw bolt 1 will still
become loose after long period of use on a workpiece that is subject to
vibration. And, an burglar can remove the bolt 1 from the workpiece
easily if he screw the nuts 12, 13 off the bolt I one after the other. In
other words, such screw bolt I can't prevent workpiece from being
stolen by burglars.
Referring to Fig. 2, conventionally, a hole 21 is formed on a lateral
side of a nut 2, and an iron wire 22 is connected to both the hole 21 of
the nut 2 and another stationary object at two ends after a screw bolt 1 is
passed through a workpiece 6 and a stationary object (not numbered) and
screwed into the nut 2. Thus, the nut 2 can't be turned, and the bolt 1 is
less likely to become loose. And, a workpiece can be fixed to other
objects with the bolt and the nut. However, such bolt and nut 1, and 2
still can't prevent the workpiece from being stolen because the iron wire
22 can be easily cut, and the nut 2 can be turned relative to the bolt 1
after the iron wire 22 is cut.
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CA 02438817 2008-01-23
Si.JMMARY OF THE INVENTION
It is desirable to provide an anti-burglar screw bolt, which can't become
loose after tong period of use on a workpiece subject to vibration, and which
can't be reinoved from a workpiece without tools especially designed to undo
it.
An anti-burglar screw bolt described herein below includes a bolt, first
and second pads, and a nut. The bolt head and the nut are hexagonal, and
consist of six sections of saxne shape each having a slope and abutting a
lower
end of adjacent section at a higher end. Eacli of the pads has six slopes like
those of the bolt head; each of the pads has radial pointed bars formed on the
other side, and gaps on lateral side for a tool to engage that is especially
designed for undoing the bolt. The radial pointed bars of the pads are driven
into surfaces of workpieces by the bolt when the bolt is used.
According to one aspect of the invention there is provided an
improvement on structure of an anti-burglar screw bolt, comprising:
a bolt; a head of the bolt having a hexagonal shape, and consisting of six
sections of a same shape; each of the six sections including a wedge-shaped
slope on a bottom side, and abutting a lower end of an adjacent section at a
higher end thereof so that a stopping edge is formed on the higher end
thereof;
a first pad and a second pad; each of the pads having a central through
hole and six sections of a same shape around the through hole; each of the six
sections of each of the pads having a sloping surface, and abutting a lower
end
of an adjacent section at a higher end thereof so that an engaging edge is
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CA 02438817 2008-01-23
formed on the higher end thereof; each of the pads having radial pointed
insertion bars formed on other side at spaced apart positions;
a nut; the nut having a hexagonal shape, and six sections of a same
shape; each of the six sections of the nut having a wedge-shaped slope on one
side thereof, and abutting a lower end of an adjacent section at a higher end
thereof so that an engaging edge is formed on the higher end thereof;
the bolt being passed tlirough the first pad, workpieces, and the second
pad in sequence, and being screwed into the nut to fasten the workpieces
together with the radial pointed insertion bars being driven into surfaces of
the
workpieces;
wherein each of the radial pointed insertion bars has a slope on one side,
and a straight side on other side thereof; the slopes of the radial pointed
insertion bars facing a same direction as corresponding sloping surfaces
formed
on opposite side of the pads so as to help the radial pointed insertion bars
to be
driven into the surfaces of workpieces with increased ease.
BRIEEF DESCRIPTION OF THE DRAWIly'GS
The present invention will be better understood by reference to the
accompanying drawings, wherein:
Fig. 1 is a view of the first conventional screw bolt joined to a workpiece
in the Background,
Fig. 2 is a view of the second conventional screw bolt joined to a
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CA 02438817 2003-08-28
workpiece in the Background,
Fig. 3 is an exploded perspective view of the anti-burglar screw bolt
according to the present invention,
Fig. 4 is a partial view of the anti-burglar, screw bolt of the second
embodiment of the invention joined to a workpiece,
Fig. 5 is a perspective view of a pad according to yet another
embodiment of the present invention,
Fig. 6 is a cross-sectional view of the anti-burglar screw bolt
according to the present invention; and,
Fig. 7 is a view of the anti-burglar screw bolt of the present
invention being turned loose by means of a tool especially designed for
it.
DETAILED DESCRIPTION OF TFLE PREFERRED EMB DIMENTS
Referring to Fig. 3, an anti-burglar screw bolt according to the
present invention includes a bolt 3, pads 4, and a nut 5.
The bolt 3 consists of a head 31, and a shank 32; threads are formed
on the shank 32. The head 31 has a hexagonal shape, and consists of six
sections of the same shape joined together; each of the six sections of the
same shape includes a lateral side 311, and a wedge-shaped slope 312 on
a bottom side thereof; each of the six sections of the same shape always
abuts a lower end of an adjacent section at a higher end thereof so that a
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CA 02438817 2003-08-28
stopping edge 313 is formed substantially perpendicular to the shank 32
on the higher end of each of the six sections of the same shape.
The pad 4 has a ring shape, having a central round through hole 41
and six sections of the same shape around the through hole 41; the outer
diameter of the pad 4 is substantially equal to the length of the longest
line across the bolt head 31, and the inner diarneter of the pad 4 is
slightly bigger than the diameter of the bolt shank 32; each of the six
sections of the same shape has a sloping surface 42; each of the six
sections of the same shape always abuts a lower end of an adjacent
section at a higher end thereof so that an engaging edge 43 is formed on
the higher end of each of the six sections of the same shape; gaps 45 are
formed on lateral portions of at least one pair of opposing sections of the
same shape of the pad 4. Furthermore, pointed insertion bars 44 are
formed on the other side of the pad 4 in a radial manner; referring to Fig.
6, each of the pointed insertion bars 44 has a vertical side 441, and a
sloping side 442, which faces the same direction as a corresponding
sloping surface 42.
A pad 7 is provided, which has, partly like the pad 4, six sloping
surfaces of same shape on one side, and radial pointed insertion bars (not
numbered) on the other side but has hexagonal shape instead of round
ring shape. The pad 7 can be used with a spanner.
Referring to Fig. 5, a pad 4' of the second embodiment can be used
instead of the pad 4; the pad 4' has a central round through hole 41',
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gaps, and sloping surfaces 42' forrned on six sections of the same shape
around the through hole 41', which are the same as those of the pad 4.
The difference between the pads 4 and 4' is that the pad 4' is formed
with radial pointed insertion bars 44', which have two sloping sides
instead of one. And, referring to Fig. 5 again, each of the six sections of
the pad 4' is further made to ascend gradually from an outward edge
towards an inward edge thereof so that each of the pointed insertion bars
44' has an inward end being taller than an inward end thereof. Thus, at
the beginning of the pads 4' being fastened to a workpiece with the bolt
3, only the outer end portions of the pointed insertion bars 44' will
contact the surface of the workpiece, allowing the pad 4' to be turned on
the surface of the workpiece more easily. In other words, with such
pointed insertion bars 44', the pad 4' allows the bolt 3 to be fastened
more easily. The radial pointed insertion bars of above pads 4, 7, and 4'
are preferably equidistantly positioned.
The nut 5 has a hexagonal shape, and consists of six sections of the
same shape; each of the six sections includes a lateral side 51, and a
wedge-shaped slope 52; each of the six sections always abuts a lower
end of an adjacent section at a higher end thereof so that a stopping edge
53 is formed on the higher end of each section.
Referring to Fig. 6, in order to secure one workpeice 6 to another
workpeice, the bolt 3 is first passed through the pad 4, the two
workpeices 6, and a pad 7 in sequence, and screwed into the nut 5 at last;
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CA 02438817 2003-08-28
the pointed insertion bars 44 of the pad 4 and those of the pad 7 face the
surfaces of the workpieces 6. Then, the bolt 3 is turned relative to the nut
5; the stopping edges 313 will contact corresponding engaging edges 43
of the pad 4, and engaging edges of the pad 7 will contact the stopping
edges 53 of the nut 5 so that the pad 4 turns together with the bolt 3.
Consequently, the pointed insertion bars are driven into the workpieces
when the bolt 3 is screwed further into the nut 5. The bolt, pads, atid nut
combination can't possibly become loose even if they are used on a
workpiece that often vibrates because the sloping surfaces 42 abut the
wedge-shaped slopes 312 to hinder reverse rotation of the bolt 3, and
because the sloping surfaces of the pad 7 abut the wedge-shaped slopes
52 to hinder a loosening rotation of the nut 3 relative to the bolt 3.
One spanner has to be used on the pad 7, and another spanner has to
be used on either one of both the bolt 3 and the nut 5 so that the bolt
combination can be undone. In addition, conventional spanners or
wrenches can't be used to hold the pad 4 in position because the pad 4 is
round. Therefore, if the pad 7 is replaced with another pad 4, the bolt,
pads, and nut combination of the present invention can't be undone
unless there is a tool at hand, as shown in Fig. 7, which is especially
designed for the pads 4, and can engage the gaps 45. In other words, the
present invention can prevent burglars from succeeding in stealing the
workpieces 6.
7

Representative Drawing