ELECTRICAL CONNECTOR TO TERMINATE MOTOR FIELD COIL WIRES

CONNECTEUR ELECTRIQUE POUR TERMINAISON DE CONDUCTEURS DE BOBINE D'EXCITATION DE MOTEUR

English Abstract

ABSTRACT
An electrical connector comprising an insulating
housing moulded of plastics material with a contact-
receiving cavity open at a top, the walls of which
cavity are formed with two aligned wire-receiving slots
which extend downwardly from the top, a stuffer member
upstanding from the floor of the cavity at a location
between the slots and a contact stamped and formed from
a single piece of sheet metal stock with two opposed
plates having aligned wire-receiving slots, at least
one of which is core-contacting, the slots having blind
ends in the plates and opening out at mouths at one end
of the plates to extend between transverse portions
connecting the plates together at the one end, the other
end of at least one plate being adapted for connection
to another wire, the contact being receivable with the
one end leading as an interference fit in the cavity
with all the slots in alignment and the stuffer extending
between the transverse portions of the contact. The
invention includes the contact per se.

Claims

The embodiments of the invention for which an exclusive
property or privilege is claimed are as follows:-
1. An electrical connector comprising an
electrically insulating housing moulded of plastics
material with a contact-receiving cavity open at a top,
two opposed walls of which cavity are each formed with a
respective one of two aligned wire-receiving slots which
extend downwardly from the top, a stuffer member
upstanding from the floor of the cavity at a location
between the slots, and a contact stamped and formed from
a single piece of sheet metal stock with two opposed
plates each having a respective one of two aligned
wire-receiving slots, at least one of the slots being
adapted to establish electrical connection with a wire
when inserted therein, the slots each having a blind end
in the respective plate and opening out at a mouth at
one end of the respective plate to extend between
transverse portions connecting the plates together at
the one end, a tang being provided on an edge of one
or both opposed plates, the other end of one plate being
adapted for connection to another wire, the contact
being receivable with the one end leading as an
interference fit in the cavity with the or each tang in
engagement with a cavity wall and all the slots in
alignment, the stuffer extending between the transverse
portions of the contact.
2. An electrical connector according to Claim 1,
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in which the other end of one of the plates is
reversely bent to define a contact tongue having a
wire-engaging edge adjacent the other plate.
3. An electrical connector according to Claim 1
or Claim 2, in which each plate is provided with two
pairs of the said tangs, one tang of each pair being
located on an opposite edge of the plate from the other
tang of the pair, the pairs being adjacent the blind
end of the contact slot and the transverse portion
respectively.
4. An electrical connector according to Claim 1
or Claim 2, in which the transverse portions are bent
upwardly to project on opposite sides of the stuffer.
5. An electrical connector according to Claim
1, in which the housing is annular and contact-receiving
cavities are formed at predetermined intervals along
the housing top.
6. An electrical connector according to Claim 5,
in which locating pins are formed at predetermined
intervals along the bottom of the housing.
7. A contact for use in a connector according to
Claim 1, which contact is stamped and formed from a
single piece of sheet metal stock with two opposed plates
each having a respective one of two aligned wire-receiving
slots, at least one of the slots being adapted to establish
electrical connection with a wire when inserted therein,
the slots each having a blind end in the respective plate
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and opening out at a mouth at one end of the plate to
extend between transverse portions connecting the
plates together at the one end, the other end of one
plate being adapted for connection to another wire, a
tang being provided on an edge of a plate.
8. A contact according to Claim 7, in which the
said other end of one plate is reversely bent to define
a contact tongue having a wire-engaging edge adjacent
the other plate.
9. A contact according to Claim 7 or 8, in which
each plate is provided with two pairs of the said tangs,
one tang of each pair being located on an opposite edge
of the plate from the other tang of the pair, the pairs
being adjacent the blind end of the contact slot and the
transverse portion respectively.
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Description

8633/8642
~(~53770
The invention relates to electrical connectors.
An electrical connector according to the
invention comprises an electrically insulating housing
moulded of plastics material with a contact-receiving
cavity open at a top, two opposed walls of which cavity
are each formed with a respective one of two aligned
wire-receiving slots which extend downwardly from the
top, a stuffer member upstanding from the floor of the
cavity at a location between the slots, and a contact
stamped and formed from a single piece of sheet metal
stock with two opposed plates each having a respective
one of two aligned wire-receiving slots, at least one
of the slots being adapted to establish electrical
connection with a wire when inserted therein, the slots
each having a blind end in the respective plate and
opening out at a mouth at one end of the respective
plate to extend between transverse portions connecting
the plates together at the one end, a tang being
provided on an edge of one or both opposed plates, the
other end of one plate being adapted for connection to
another wire, the contact being receivable with the one
end leading as an interference fit in the cavity with the
tang in engagement with a cavity wall and all the slots
in alignment, the stuffer, extending between the
transverse portions of the contact.
According to the invention there is also provided
a contact for use in the above connector which contact is
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1053770 8633/8642
stamped and formed from a single piece of sheet metal
stock with two opposed plates each having a respective
one of two aligned wire-receiving slots, at least one
of the slots being adapted to establish electrical
connection with a wire when inserted therein, the slots
each having a blind end in the respective plate and
opening out at a mouth at one end of the plate to extend
between transverse portions connecting the plates together
at the one end, the other end of one plate being
adapted for connection to another wire, a tang being
provided on an edge of one or both opposed plates.
A particular application of the invention is the
termination of wires of a coil for example of a field
coil of an electric motor.
Specific examples of the invention will now be
described with reference to the accompanying drawings
in which:-
Figure 1 is a perspective view of a field coil
assembly of an electric motor having an electrical
connector mounted thereon;
Figure 2 is a fragmentary perspective view of
the electrical connector;
Figure 3 is a perspective view of the contact of
the connector;
Figures 4 to 7 are perspective views of other
examples of contacts;
Figure 8 is a fragmentary perspective view of
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1053770
another exa~ple of connector.
The assembl~ of Figure 1 includes a laminated iron core 11
forming pole pieces around which are wound coils 13 lnsulated from
the core by insulating sheets 12. An annular connector housing 14
integrally moulded from plastics material is secured on one end of
the core both by pins 15 on the housing base, which pins project into
lamination alignment holes formed in the core during manufacture, and
by the coils. The housing is formed with a series of box-like structures
16 defining contact-receiving cavities open at a top, one pair of
opposed walls of the cavities being formed with aligned wire gripping
slots which extend downwardly from an upper edge of each wall. A
rectangular wire stuffer 18 upstands from the cavity floor between the
slots 17.
The contact 19 received in each cavity is stamped and formed
from a single piece of sheet metal stock and comprises two opposed
plates 21 (Figures 2 and 3) having aligned wire-receiving slots 23
which open out to define wire-receiving mouths at one end of the plates
which ends are joined by transverse portions 22. The other end of one
plate is reversely bent to define a contact tongue 24 which extends
towards the other plate. A wire-locating V-section depression 25 is
stamped in the free end of the tongue. Each plate is provided with two
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8633/8~42
1053770
pairs of tangs 26, 27, one tang of each pair being
located on an opposlte edge of the plate from the other
tang of the pair, the pair 26 being adjacent blind ends
32 of the slots 23 and the pair 27 being adjacent the
transverse portion 22.
In use the annular connector housing is mounted
on the end of the pole pieces by the pins and the coils
are then wound. The free ends of the coil wires 28 are
inserted in the slots 17 which locate them across the
stuffer 18. The contact is then inserted into the cavity
so that the stuffer is received between the transverse
portions 22 ensuring that the wire 28 is pushed fully
along the slots 23 to the blind ends 32 where the wire
may remain under some pressure from the stuffer. The
edges of the slots 23 penetrate insulation on the wire
to connect to the core. The tangs bight into the cavity
wall to retain the contact in the cavity. Tangs 27 also
urge the slot walls together. Thus, the slot walls can
be considered to be cantilever beams and the tangs 26
may function as fulcrums. This feature enables a
plurality of coil wires to be retained in the slots
reliably connected to the contacts. A lead wire from
external circuitry can then be connected to the contact
by pushing the lead wire between the free end of the
tongue 24 and the adjacent plate 21 so that the wire is
gripped between the tongue and plate.
An advantage of the invention is that the assembly

1(~5~770
steps can be carried out automaticall~ and the ends of the coil wires
can be located accurately in the housing immediately after the coil
has been wound and prior to connection to the lead wire pre~enting the
last few turns becoming unwound.
In an alternative example shown in Figure 4, the contact is
modified by the provision of a double thickness tab 34 instead of the
tongue 24 which tab is perforated at 35, in which perforation a lead
wire can be located for soldering.
In the example, shown in Figure 5, a double thickness post
around which a lead wire may be wrapped is provided instead of the tab.
In the example shown in Figure 6, the tongue is retained and
a tab 37 perforated at 38 extends from the opposite plate and in the
example shown in Figure 7 a crimping ferrule replaces the tongue 24.
In the example shown in Figure 8 the transverse portions 41
are folded upwardly to extend on opposite sides of the stuffer assisting
in locating the wire on the stuffer.
.~