Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Headed fastener element with nut – washer – securing means or cap – Headed bolt or screw with threads and complementary nut
Reexamination Certificate
2000-11-15
2002-02-05
Saether, Flemming (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Headed fastener element with nut, washer, securing means or cap
Headed bolt or screw with threads and complementary nut
C411S162000, C411S164000, C411S188000
Reexamination Certificate
active
06343904
ABSTRACT:
BACKGROUND OF THE INVENTION
1. 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.
2. Description of the Related Art
In the construction of steel frameworks, to facilitate construction and ensure safety, tension bolt assemblies are generally used to couple articles.
Referring to
FIGS. 1 and 2
, a conventional tension bolt assembly
1
is adapted to bind first and second 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
111
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
12
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 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 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 projections that are angularly spaced apart and that extend in radial outward 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 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.
REFERENCES:
patent: 1882089 (1932-10-01), Olson
patent: 2271732 (1942-02-01), Chappuis
patent: 2562032 (1951-07-01), Gutenshon
patent: 4290337 (1981-09-01), Kuwata
patent: 4377361 (1983-03-01), Frieberg
Akin Gump Strauss Hauer & Feld L.L.P.
Hexico Enterprise Co., Ltd.
Saether Flemming
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