Electrical connectors – Metallic conductor terminal having conductor sheath engaging... – Resilient or spring-biased socket or clip type terminal
Reexamination Certificate
2001-02-02
2002-10-22
Nguyen, Khiem (Department: 2839)
Electrical connectors
Metallic conductor terminal having conductor sheath engaging...
Resilient or spring-biased socket or clip type terminal
C439S877000
Reexamination Certificate
active
06468116
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a terminal fitting that can be crimped into connection with a wire.
2. Description of the Related Art
A terminal fitting that can be crimped into connection with a wire is disclosed in Japanese Unexamined Patent Publication No. 4-209471, and is identified generally by the numeral
100
in
FIGS. 9
to
13
of this application. The terminal fitting
100
has a barrel-type wire-fastening portion
101
with a bottom wall
102
and first and second fastening pieces
103
,
104
that extend upward from the left and right side edges of the bottom wall
102
.
An automated apparatus is used to crimp the wire-fastening portion
101
into connection with a wire
105
. First, as shown in
FIG. 9
, the wire-fastening portion
101
is placed on an anvil
106
and the wire
105
is placed between the two fastening pieces
103
,
104
. A crimper
107
is located above the anvil
106
and is provided with an arch-shaped guide surface
108
formed with a stepped stopper
109
substantially at the uppermost position. The crimper
107
then is lowered to crimp the fastening pieces
103
,
104
to the wire
105
.
During the lowering process, a leading end
103
A of the first crimping piece
103
contacts the stopper
109
and is held tense, and a leading end
104
A of the second crimping piece
104
contacts the leading end
103
A of the first crimping piece
103
and is held tense (see FIG.
10
).
Thereafter, the leading ends
103
A,
104
A of the first and second crimping pieces
103
,
104
are bent inwardly. More particularly, the first crimping piece
103
departs from the stopper
109
and is bent along the guide surface
108
with a decreasing radius of curvature. Simultaneously, the second crimping piece
104
is bent along the inner side surface of the first crimping piece
103
with a decreasing radius of curvature. As a result, the first and second crimping pieces
103
,
104
are crimped and fastened to the outer circumferential surface of the wire
105
.
The crimping of the terminal fitting
100
may cause the leading end
104
A of the second crimping piece
104
to be bent away from the intended bending direction, as shown in
FIGS. 11 and 12
, and into a reverse fold, as shown in FIG.
13
. If this occurs, the folded leading end
104
A may be broken along the fold and may come out through a clearance between the first crimping piece
103
and the wire
105
. As a result, a clearance may be formed between the first crimping piece
103
and the wire
105
, and a reduced fastening force may result.
The above-described problem is particularly prominent in terminal fittings in which a projection
110
is formed on the inner side surface of the second crimping piece
104
for strengthening a fastening force so that the projection
110
bites in the outer circumferential surface of the wire
105
.
In view of the above problem, an object of the present invention is to securely crimp crimping pieces into connection with a wire.
SUMMARY OF THE INVENTION
The subject invention is directed to a terminal fitting that comprises a wire-fastening portion with a bottom wall and at least first and second crimping pieces that extend from the bottom wall. The wire-fastening portion can be crimped into connection with a wire such that the second crimping piece is deformed to reduce a radius of curvature while moving substantially along the inner side surface of the first crimping piece. Thus, the first and second crimping pieces substantially surround the outer circumferential surface of the wire.
The second crimping piece is recessed to form a deformation-facilitating portion or a weakened portion that facilitates a bending or deformation that inclines a leading end portion of the second crimping piece inwardly. Accordingly, a crimping error that deforms the leading edge in a direction opposite from an intended direction can be prevented.
Preferably, the second crimping piece is formed with a projection on the inner side surface. The projection is dimensioned and configured to bite into the outer circumferential surface of the wire. The deformation-facilitating portion preferably is formed between the projection and the leading end of the second crimping piece. Accordingly, the second crimping piece is bent between the leading edge and the projection to incline the leading edge inwardly. Angles of inclination of the bent leading end with respect to a guide surface and the first crimping piece are small as compared to a case where the second crimping piece is bent between the bottom wall and the upper projection. Thus, the second crimping piece is moved smoothly along the inner side surface of the first crimping piece to reduce a diameter.
The deformation-facilitating portion may comprise a groove that extends along at least one side surface of the second crimping piece, and preferably along the inner side surface of the second crimping piece. Additionally, the groove preferably is aligned substantially normal to the extension of the second crimping piece. Thus the groove lies substantially along a bending line, and bending can be performed more securely.
The leading end of the second crimping piece is bent about a point on the outer side surface of the second crimping piece that substantially aligns with the deformation-facilitating portion. Additionally, the groove is open in the inner side surface. Accordingly, there is no likelihood that the opening edge of the groove will be caught by the inner side surface of the first crimping piece and the guide surface while the second crimping piece is deformed to a reduced diameter during the crimping process.
The deformation-facilitating portion may be formed by thinning the second crimping piece, such as by stretching the metal plate used to produce the terminal fitting.
The bottom wall may be formed with at least one bottom projection for contacting and biting into the wire.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings.
REFERENCES:
patent: 3781459 (1973-12-01), Peek
patent: 3989339 (1976-11-01), Haitmanek
patent: 5561267 (1996-10-01), Fudoo et al.
patent: 5635676 (1997-06-01), Piriz
patent: 6206727 (2001-03-01), Aoyama et al.
patent: 1 435 011 (1976-05-01), None
patent: 4-209471 (1992-07-01), None
Casella Anthony J.
Hespos Gerald E.
Nguyen Khiem
Sumitomo Wiring Systems Ltd.
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