Metal fusion bonding – Process – Using only pressure
Reexamination Certificate
1998-09-03
2001-02-27
Ryan, Patrick (Department: 1725)
Metal fusion bonding
Process
Using only pressure
C228S003100, C029S753000
Reexamination Certificate
active
06193138
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a terminal pressure welding device and a method for pressure welding a terminal onto electric wires. This improved pressure welding device can pressure weld a terminal simultaneously onto two thick wires as desired, and make the pressure welding widths of terminals as uniform as possible so that the terminals can surely be inserted into the terminal receiving chambers of a connector.
2. Related Art
FIG. 8
illustrates a conventional connector. A connector housing
1
is provided with a plurality of terminal receiving chambers
2
. Each of the terminal receiving chambers
2
accommodates a terminal
4
which is pressure welded onto the edge of a wire
3
and held by a flexible stopper arm (not shown) inside the chamber. However, a terminal
4
′ pressure welded onto the edges of two wires
3
and
3
′ (double pressure welding) may be inserted into each terminal receiving chamber
2
in the case of branch connection, and the like.
The terminal
4
comprises an electric contact
4
A for a mating terminal (not shown), and a wire pressure welding portion
4
B. The wire pressure welding portion
4
B is provided with a pair of wire barrels
5
for the conductor
3
a
of the wire
3
, and a pair of insulator barrels
6
for an insulating cover layer
3
b.
The terminal
4
′ for double pressure welding has substantially the same structure as that of the terminal
4
, but a pair of wire barrels
5
′ and a pair of insulator barrels
6
′ of a wire pressure welding portion
4
B′ are made a little longer than the barrels
5
and
6
of each terminal
4
connected to only one wire
3
.
The positions of the two wires
3
and
3
′ to be pushed into the pair of insulator barrels
6
′ can be categorized roughly into the following four types: (A) a vertical arrangement; (B) a left-inclined arrangement; (C) a right-inclined arrangement; and (D) a horizontal arrangement.
FIG. 10
illustrates a conventional double pressure welding device which comprises a crimper
7
, an anvil for placing the terminal
4
′, and a wire holding member
9
. The wire holding member
9
descends right behind the wire pressure welding member
4
B′ (i.e., in an axially spaced position) to push the pair of wires
3
and
3
′ into a space between the pair of insulator barrels
6
′ by the horizontal holding surface
9
a
. After that, the crimper
7
descends to caulk the barrels
6
′ by covering the wires
3
and
3
′ with them.
At the bottom of the crimper
7
, as shown in
FIG. 11
, a shallow caulking groove
7
b
is formed on one side of the center (on the left side in the figure) extending from an introducing groove
7
a
which becomes wider at the opening end, while a deep caulking groove
7
c
is asymmetrically formed on the other side (on the right side in the figure). The grooves
7
b
and
7
c
are connected via an inclined surface
7
d.
When actually performing double pressure welding, the pair of wires
3
and
3
′ in the vertical arrangement shown in
FIG. 9A
are placed between the insulator barrels
6
1
′ and
6
2
′, and they remain in the vertical arrangement, since the wire holding member
9
descends vertically. If the diameter of the wires is large, the arranged height of the wires
3
and
3
′ becomes higher than the edge
6
a
′ of the insulator barrel
6
1
′ on the side of the shallow caulking groove
7
b
, as shown in FIG.
11
.
If the crimper
7
descends in such condition, the edge
6
a
′ of the insulator barrel
6
1
′ cannot be placed below the other insulator barrel
6
2
′, and the edge
6
b
′ of the insulator barrel
6
2
′ cannot be interposed between the insulator barrel
6
1
′ and the caulking groove
7
b
. This causes the edges
6
a
′ and
6
b
′ to collide with each other. As a result, the entire shape becomes somewhat flat, and the insulator barrel
6
2
′ on the right side is buckled in the middle, as shown in FIG.
12
. In such pressure welding condition, there is a problem that, since the pressure welding width of the terminal becomes large, the terminal
4
′ cannot be inserted into the terminal receiving chamber
2
shown in FIG.
8
.
Even if the terminal is successfully inserted, the buckled portion will be cracked, and the pressure welding strength is low. When the wires are pulled, the tensile strength will act directly on the wire barrels
5
′, which might result in cutoff due to vibration.
SUMMARY OF THE INVENTION
The principal object of the present invention is to provide a terminal pressure welding device and method by which even thick wires can be pressure welded as desired, and the pressure welding widths of the terminals can be made as uniform as possible so that the terminals can surely be inserted into the terminal receiving chamber of a connector.
To achieve the above object, a first aspect of the present invention provides a terminal pressure welding method comprising the steps of: pushing wires into a space between a pair of barrels by a wire holding member; restricting the position of the wires between the pair of barrels by the wire holding member, so that an ingress allowance space can be ensured for allowing the edge of one of the barrels to get under the other barrel; and caulking the barrels by overlapping one of the barrels on the other by a crimper, so that the wires can be covered with the barrels.
In accordance with a second aspect of the present invention, the terminal pressure welding device used in the above method is characterized in that a wire-holding inclined surface, which descends from one of the barrels toward the other is provided on the bottom edge of the wire holding member.
In accordance with the first and second aspects of the present invention, the two wires are positioned lower than the edge of the insulator barrels at the time of double pressure welding, so that an ingress allowance space can be ensured for allowing the edge of one of the barrels to get under the other barrel. Accordingly, the edge of one of the barrels gets under the other barrel without the barrels colliding with each other, and the caulking is performed with the barrels overlapping on each other. Thus, flat and buckled pressure welding can be prevented, and all of the terminals can surely be inserted into the terminal-receiving chambers of a connector. The possibilities of cutoff due to a decrease in pressure welding strength can also be eliminated.
A third aspect of the present invention provides a terminal pressure welding device which comprises: a wire holding member for pushing wires into between a pair of barrels; a crimper for caulking the pair of barrels by overlapping one of the barrels on the other barrel, so that the wires can be covered with the barrels; and an asymmetrically reversed V-shaped wire holding groove provided on the bottom edge of the wire holding member and made up of a long wire holding inclined surface which descends from one of the barrels toward the other and a short wire restricting inclined surface which descends in the opposite direction to the wire holding inclined surface.
In accordance with the third aspect of the present invention, by virtue of the reversed V-shaped wire holding groove made up of the long wire-holding inclined surface and the short wire-restricting inclined surface, the positioning of the wires between the barrels can be performed as desired, and wire buckling after pressure welding can be prevented by the stopper function of the wire restricting inclined surface.
In accordance with a fourth aspect of the present invention, the bottom of the wire holding groove made up of the wire-holding inclined surface and the wire-restricting inclined surface serves as a wire-holding portion and is rounded to accommodate the outer surface of the wires. Thus, the coating of the wires can be protected from damage which might be caused by the wire-holding member when it pushes
Armstrong, Westerman Hattori, McLeland & Naughton
Edmondson L.
Ryan Patrick
Yazaki -Corporation
LandOfFree
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