Note: Descriptions are shown in the official language in which they were submitted.
2 ~ s~
Ul-82250
ELECTRICAL CONNECTOR
This invention relates to an electrical
connector, and more particularly to an electrical
connector capable of fixing contacts by press-fitting at
predetermined exact positions of an insulating main body
05 by press-fitting.
Various electrical connectors have been used in
electric and electronic appliances. An actual example
is illustrated in Figs. la and lb. The electrical
connector shown in Fig. la includes an insulating main
body 1 and contacts 2A and 2B press-fitted in a locator
portion 3 of the main body 1 and fixed thereat.
Such a receptacle connector is arranged at
a predetermined position, for example, on a aircuit
board 4 and fixed thereat by means of set screws 5 or
the like.
Fig. lb illustrates a condition that the
receptacle connector is arranged and fixed onto
a circuit board and a relationship between the arranged
receptacle connector and a plug connector to be fitted
with the recepta~le connector.
Tail portion~ of the contact~ 2A and 2B fixed to
the insulating main body 1 extend through through-holes
,
!
2~2~
4A and 4B provided in the circuit board 4 and elec-
trically connected to a pattern of the circuit board on
its back side by soldering as shown in Fig. lb.
The receptacle connector mounted on the circuit
o~ board 4 is adapted to be fitted with a plug connec~or
separately prepared.
With one method of fixing contacts at a pre-
determined position to an insulating main body of the
connector of this kind, as shown in Fig. 2, a fixing
1~ portion 11 of a contact tail is press-fitted in a slit
32 of a locator plate 3 so that the contact tail is
positioned relative to the locator plate 3.
In this method, however, in order to obtain
a high positioning force which serves to securaly fix
1~ the contact tail to prevent it from shifting from the
position, it is necessary to enhance the force with
which the fixing portion of the contact urges inner
walls of the slit~ For this purpose, the fixing portion
of the contact i~ widened to provide a widened portion
111. As ~ result, the widened portion 111 cuts or
scrapes the inner walls 321 of the slit 32 when the
widened portion 111 is press-fitted in the slit 32.
Therefore, chips of the inner walls 321 accumulate, for
example, between a wall surface 322 of the slit ~2 at
2~ its bottom and the widened portion 111 of the fixing
portion 11 of the contact tail, with the result that the
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contact tail 11 cannot be positioned at a predetermined
position, which is a technical problem to be solYed for
lon~ time.
As shown in Fig. 3, moreover, there is another
0~ problem in that if the widened portion 111 is chamfered
as shown at 112, contact areas between the slit 32 and
the contact tail becomes small so that fixing force is
weak, with the result that the position of the contact
tail is likely to change.
It is an object of the invention to provide
an improved electrical connector which eliminates all
the disadvantages of the prior art.
In order to accomplish this object, in
an electrical connector including an insulating main
1~ body having a locator and contacts press-fitted in slits
formed in the locator and fixe~l thereat, according to
the invention each o the contacts comprises a widened
portion whose both ends are ine~lined rearward of
inserting direction for press-fitting of the contact,
and each contact has been distal ends and bottoms of the
widened portion an elasticity against a force narrowing
a distance between the distal ends.
With the above arrangemen~, the distal ends of
the widened portion are inclined rearward of inserting
2~ direction for press-fitting and the distance between the
distal ends tends to narrow elastically. Therefore,
during the insertion of the widened portion into the
slit, the distal ends of the widened portion deform
toward each other 50 that the force urging inner walls
of the slit becomes weak with the result th~t the
OS widened portion can be inserted into the slit without
scraping the inner walls of the slit. If the widened
portion tends to remove from the slit, the distal ends
of the widened portion are likely to deform away from
each other so that urging force of the distal ends
against the inner walls of the slit increases to prevent
any dislodgment of the contact from the slit.
As the electrical connector according to the
invention comprises the above construction with the
above effects, the inner walls of the slits are not
lK scraped in inserting the contact into the slit so that
any scraped chips are not produced. Therefore, there is
no difficulty in positioning of a contact tail due to
scraped chips. The fixing forae of the contact tail in
a removing direction is large so that the contact tail
2~ does not shift in any way. Ac&ordingly, the significant
effect of exact positioning of contacts particular to
the invention can be accomplished.
The invention will be more fully understood by
referring to the following detailed specification and
2~ claims taken in conne~tion with the appended drawings.
Figs~ la and lb illustrate a connector of the
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prior art;
Fig. 2 illustrates respective parts a contact
tail and a locator plate to which the contact tail is
fixed in a connector of the prior art;
Fig. 3 is a bottom plan view of a widened
portion of a contact tail of a connector of the prior
art;
Fig. 4 illustrates a fixing portion of a contact
used in the connector according to the invention;
Fig. 5 is a bottom plan view illustrating the
contact according to the invention;
Fig. 6 is a perspective view of a contact tail
of another embodiment o~ the invention; and
Fig. 7 is a sectional view taken along the line
in Fig. 6.
Fig. 4 is a perspectivle view illustrating
a flxing portion of a contact 2A or 2B used in
a connector according to the invention. The contact
tail 11 is provided at the fixing portion with a widened
2fl portion 111 whose outer ends are bent in the proximity
of its bottom 114 rearward of a press-fitting direction
at a determined angle. Each of the outer ends of the
widened portion 111 is slightly tapered toward its
distal end 113. Such a tapered shape is only one
example. The distal end 113 may be wider than the
bottom 114. The distal end 113 may of course have
2 ~
a width substantially equal to that of the bottom 114.
Fig. 5 illustrates on an enlarged scale the
fixing portion of the contact tail according to the
invention in section taken along the line V-V in
o~ Fig. 4. As can be seen from Fig. 5, the distal end 113
of the widened portion 111 is inclined and the portion
from the bottom 114 to the distal end 113 constitutes
a cantilever having an elasticity against a force
tending to narrow a distance a between both the distal
ends.
An angle ~ made by the portion from the bottom
14 to the distal end 113 with the contact tail is
preferably 30 to 60. The distal end 113 having the
angle ~ less than 30 disadvantageously tends to scrape
1~ inner walls of a slit 32.
In case that the angle ~ is more than 60, the
force deforming the distal endls 113 of the widened
portion 111 away ~rom each othler i~ too weak so that the
widened portion 111 is likely to be dislodged from the
slit unfavorably.
Moreover, an edge of the di~tal end 113 formed
by punching using a press die may be used as a portion
of the distal end 113 abutting against the inner wall
321 of the slit. The distal ends 113 in Fig. 5
illustrate the edges abutting against the inner walls
321 of the slit. As the distal end 113 is inclined at
~, the sharp edges of the distal ends 113 abut against
the inner walls of the slit.
However, this feature is only one example.
Other arrangements may be used so long as the widened
o~ portion of the contact and inner walls of the slit are
not likely to slide with each other. Therefore, the
edges of the distal ends 113 shown in Fig. 5 may be
chamfered or hit in pressing to be dull or rounded, if
required. This is advantageous in the case that the
1~ locator plate 3 is made of a material to be easily
scraped or press-fitting force is too large.
The contacts used in the connector according to
the invention have generally widths of 0.6 to 1.2 mm,
and lengths of 15 to 45 mm and thicknesses of 0.2 to
1~ 0.35 mm in case of the widths and lengths within the
above values.
With the contacts having the usual sizes above
described, a length b (Fig. 5) from the bottom 114 to
the distal end 113 obll~uely extending i~ 0.2 to 1.5 mm.
~0 The length b less than 0.2 mm is not preferable because
of less elasticity. The length b more than 1.5 mm is
also disadvantageous becau~e of low Plasticity resulting
in low fixing force of the contact.
With the widened portion of the contact shown in
Fig. 5, the portions from the bottoms 114 to the distal
end 113 extend straight. However, they may be curved on
2~
any side. Of course, the substantially straight
portions are advantageous in manufacturing because the
straight portions are only 0.2 to 1.5 mm in the usual
sizes.
0~ Widths c (Fig. 4) of the distal ends 113 are
preferably as wide as possible because the wider the
widths, the higher is the fixing force in stability and
reliability. However, the widths c of the distal ends
113 more than a thickness of the locator plate are
disadvantageous, because the widened portion 111 of the
contact will abut against the circuit board when the
connector is equipped on a circuit board and may shift
the fitting position.
The contacts used in this invention can be made
1~ any metallic materials so long as they have been used
for this kind of contacts. For example, the contacts
can be typically made of various copper alloys such as
phosphor bronze, solder-plated phosphor bronze,
beryllium-ropper brass, German ~ilver, Tando, Cadmium
copper and Cu-Ni-Sn alloys.
The insulating main body used in the connector
according to the invention can be made any materials so
long as they have been used for the same purpose.
However, in consideration of size, accuracy, ease to
2~ work. and stability, engineering plastic materials,
particularly liquid crystal plastics among them are
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preferable when it is desirable to improve the
reliability. Usable plastic materials are, nylon 66,
nylon 6, polyacetal, polycarbonate, PBT, PPE, PPS, PPD,
PET and the like.
o~ A width of a slit 32 provid~d in a locator into
which the contact in press-fitting is 5 to 15% narrower
than the distance a between the distal ends of the
widened portion of the contact. If it is less than 5%,
the press-fitting force is too small so that the fixing
force for the contact becomes small. If it is more than
15%, the deformation of the widened portion of the
contact becomes large to increase its elastic force so
that wall surfaces of the slit may be scraped.
~ig. 6 illustrates another embodiment of the
1~ invention which is preEerably used in the case that the
contact is made of a relatively thin material (for
example, 0.1 to 0.2 mm thickness). Fig. 7 is
an enlarged ~ectional view of the contact taken along
the line ~-~ in Fig. 6.
Referring Fig. 6, the contact 11 is folded along
its longitudinal center line into a form of a trough
over its length, thereby increasing a strength against
buckling.
With such a contact, the effect of the invention
z~ can be accomplished by folding the contact at 30 to 60
of ~ as shown in Fig. 7.
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When the folded angle ~ exceeds 45, cracks may
sometimes occur by the abrupt folding angle for some
materials. Therefore, the angle of 30 to 45 is most
preferable.
o~ While the invention has been particularly shown
and described with reference to preferred embodiments
thereof, it will be understood by those skilled in the
art that the foregoing and other changes in form and
details can be made therein without departing from the
spirit and scGpe of the invention.
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