Note: Descriptions are shown in the official language in which they were submitted.
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BOLT ASSEMBLY
FIELD OF THE INVENTION
The invention relates to a bolt assembly, more
particularly to a tension bolt assembly that can
prevent co-rotation of a washer and a shank of a bolt
member with a nut.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present
invention will become apparent in the following
detailed description of the preferred embodiment with
reference to the accompanying drawings, of which:
Figure 1 is an exploded perspective view of a
conventional tension bolt assembly;
Figure 2 is a sectional view of the conventional
tension bolt assembly when used to bind two articles
together;
Figure 3 is an exploded perspective view of the
preferred embodiment of a bolt assembly according to
the invention; and
Figure 4 is a sectional view of the preferred
embodiment when used to bind two articles together.
BACKGROUND OF THE INVENTION
In the construction of steel frameworks, to
facilitate construction and ensure safety, tension
bolt assemblies are generally used to couple articles.
Referring to Figures 1 and 2, a conventional tension
bolt assembly 1 is adapted to bind first and second
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articles 2, 3, which are respectively formed with
aligned through holes 21, 31 and opposing outer
surfaces 22, 32. As shown, the bolt assembly 1 includes
a bolt member 11, a washer 12, and a nut 13. The bolt
member 11 includes a head ill adapted to abut against
the outer surface 32 of the second article 3, and a shank
having a connecting section 112 connected to the head
111 and adapted to extend into the through holes 21,
31, an externally threaded section 113 connected to the
connecting section 112, a breakable section 114
connected to the externally threaded section 113, and
an annular groove 115 disposed between the externally
threaded section 113 and the breakable section 114.
The externally threaded section 113 is adapted to
project from the outer surface 22 of the first article
2. The breakable section 114 is formed with a plurality
of axially extending grooves.
When the bolt assembly 1 is used to bind the first
and second articles 2, 3 together, the shank of the bolt
member 11 is first extended through the aligned through
holes 21, 31 in the first and second articles 2, 3, such
that the head 111 abuts against the outer surface 32
of the second article 3. Then, the washer 2 is sleeved
on the externally threaded section 113 that projects
from the outer surface 22 of the first article 2, and
the nut 13 engages threadedly the externally threaded
section 113. Subsequently, a tool (not shown) is used
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to rotate the nut 13 so that the nut 13 urges the washer
12 to abut against the outer surface 22 of the first
article 2. At this point, the bolt assembly 1 binds
loosely the first and second articles 2, 3. Thereafter,
a bolt tightening tool 8 specific for tension bolts and
including inner and outer sleeves 81, 82 is used to
engage the breakable section 114 and the nut 13,
respectively. The outer sleeve 82 is rotated in one
direction to drive the nut 13 until a deadlock occurs.
Then, the inner sleeve 81 is rotated in a reverse
direction until the breakable section 114 breaks away
from the externally threaded section 113 at the annular
groove 115 due to the shear produced by the differential
movement of the inner and outer sleeves 81, 82. As such,
the bolt assembly 1 is fully tightened and is in a highly
tensed state.
Although the conventional tension bolt assembly 1
can firmly bind the first and second articles 2, 3
together, since the outer surfaces 22, 32 of the first
and second articles 2, 3 are generally coated with a
paint or other substance for purposes of corrosion
prevention or enhancing appearance, the friction
forces between the head 111 and the outer surface 22
of the first article 2 and that between the washer 12
and the outer surface 32 of the second article 3 are
relatively small, thereby resulting in undesired
co-rotation of the washer 12 with the nut 13, as well
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as rotation of the bolt member 11 with the nut 13, during
the process of bolt tightening. As such, the locking
force of the bolt assembly 1 cannot be controlled
accurately.
SUMMARY OF THE INVENTION
Therefore, the main object of the present invention
is to provide a bolt assembly that can prevent co-
rotation of a washer and a bolt member with a nut during
a bolt tightening operation.
Accordingly, a bolt assembly of this invention
includes a bolt member, a washer, and a nut. The bolt
member includes a head and a shank. The head has an
article confronting side. The shank has a connecting
section that is connected to the article confronting
side of the head, an externally threaded section that
extends from the connecting section, a breakable tip
that extends from the externally threaded section and
that is formed with a plurality of axially extending
and angularly displaced teeth, and an annular groove
that is formed at a juncture of the externally threaded
section and the breakable tip. The washer is sleeved
on the shank of the bolt member, and has an article
confronting side and a nut confronting side opposite
to the article confronting side of the washer. The
article confronting side of the washer is formed with
a plurality of anti-skid proj ect ions that are angularly
spaced apart and that extend in radial outward
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directions relative to the shank of the bolt member.
The nut engages threadedly the externally threaded
section of the shank, and has opposing first and second
surfaces respectively disposed remote from and
5 proximate to the nut confronting side of the washer such
that the second surface of the nut urges the nut
confronting side of the washer toward the head of the
bolt member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Figures 3 and 4, the preferred
embodiment of a bolt assembly according to the present
invention is adapted to bind first and second articles
71, 72 which are respectively provided with aligned
through holes 712, 722, and opposing outer surfaces 711,
721.
The bolt assembly is shown to include a bolt member
4, a washer 5, and a nut 6. The bolt member 4 includes
a head 41 and a shank 42. The head 41 has an article
confronting side adapted to abut against the outer
surface 711 of the first article 71, and is formed with
a plurality of anti-skid ribs 411 that are angularly
spaced apart and that extend in radial outward
directions relative to the shank 42. The shank 42 has
a connecting section 421, an externally threaded
section 422, a breakable tip 423, and an annular groove
424. The connecting section 421 is connected to the
article confronting side of the head 41. The
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externally threaded section 422 extends from the
connecting section 421. The breakable tip 423 extends
from the externally threaded section 422, and is formed
with a plurality of axially extending and angularly
displaced teeth. The annular groove 424 is formed at
a juncture of the externally threaded section 422 and
the breakable tip 423, and has a predetermined depth.
The shank 42 is adapted to extend through the aligned
through holes 712, 722 such that a length of the
externally threaded section 422 projects from the outer
surface 721 of the second article 72.
The washer 5 is sleeved on the shank 42 of the bolt
member 4, and has an article confronting side 51 and
a nut confronting side 52 opposite to the article
confronting side 51 of the washer 5. The article
confronting side 51 of the washer 5 is adapted to abut
against the outer surface 721 of the second article 72.
The article confronting side 51 and the nut confronting
side 52 of the washer 5 are respectively formed with
a plurality of first and second anti-skid projections
53 that are angularly spaced apart and that extend in
radial outward directions relative to the shank 42 of
the bolt member 4.
The nut 6 engages threadedly the externally threaded
section 422 of the shank 42, and has opposing first and
second surfaces 61, 62 respectively disposed remote
from and proximate to the nut confronting side 52 of
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the washer 5 such that the second surface 62 of the nut
6 urges the nut confronting side 52 of the washer 5
toward the head 41 of the bolt member 4. The second
surface 62 of the nut 6 is formed with an axially
extending annular ring 621 disposed around the shank
42 of the bolt member 4 and surrounded by the second
anti-skid projections 53 on the nut confronting side
52 of the washer 5. As such, the annular ring 621
contacts the nut confronting side 52 of the washer 5,
and prevents the second anti-skid projections 53 from
interfering with rotation of the nut 6 relative to the
shank 42.
When using the bolt assembly of this invention to
secure the first and second articles 71, 72, the shank
42 is first extended through the aligned through holes
712, 722, and the washer 5 and the nut 6 are sleeved
on the shank 42. Then, a tool (not shown) is used to
cause the annular ring 621 of the nut 6 to abut against
the nut confronting side 52 of the washer 5, thereby
urging the first anti-skid projections 53 on the
article confronting side 51 of the washer 5 to abut
against the outer surface 721 of the second article 72.
The bolt assembly is tightened such that the second
anti-skid projections 53 are set in the outer surface
721 of the second article 72. Besides, the anti-skid
ribs 411 are brought to set in the outer surface 711
of the first article 71 by rotation of the nut 6.
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Subsequently, a bolt tightening tool 8 adapted for use
specifically with tension bolts and including inner and
outer sleeves 81, 82 is employed to engage the breakable
tip 423 and the nut 6, respectively. The outer sleeve
82 is rotated in one direction to drive the nut 6 to
a deadlock. Then, the inner sleeve 81 is rotated in
a reverse direction until the breakable tip 423 breaks
away from the externally threaded section 422 at the
annular groove 424, thereby tightening fully the bolt
assembly against the first and second articles 71, 72.
During tightening of the bolt assembly, since the
anti-skid ribs 411 and the first anti-skid projections
53 are embedded in the outer surfaces 711, 721 of the
first and second articles 71, 72, respectively, the
washer 5 is prevented from rotating with the nut 6, and
the bolt member 4 is also prevented from rotating with
the nut 6. As such, the locking force can be controlled
to be within a predetermined range.
Furthermore, since the washer 5 is provided with
first and second anti-skid projections 53 on both sides
thereof, and since both of the first and second
anti-skid projections 53 are configured to surround the
annular ring 621 of the nut 6, the user need not bother
with the orientation of the washer 5 during
installation of the bolt assembly. Thus, working
efficiency can be enhanced.
While the present invention has been described in
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connection with what is considered the most practical
and preferred embodiment, it is understood that this
invention is not limited to the disclosed embodiment
but is intended to cover various arrangements included
within the spirit and scope of the broadest
interpretation so as to encompass all such
modifications and equivalent arrangements.
