[0001] This invention relates to electrical connectors, particularly but not exclusively,
electrical connectors for making electrical connection to electromagnetic relays and
similar electrical devices where a body of the device has a plurality of parallel
blade terminals extending from one face thereof.
[0002] It is known to provide a connector comprising a block-like moulded synthetic resin
body having therein, parallel passages within which socket terminals are housed. The
socket terminals each include a locking lance which co-operates with an abutment on
the wall of its respective passage to resist withdrawal of the socket terminal from
its passage in one direction, the terminal and passage having abutting surfaces locating
the terminal in the passage against movement in the direction opposite the withdrawal
direction.
[0003] It is desirable to provide additional locking of the terminals against withdrawal
and it has been proposed to provide this by means of a locking bar which is inserted
into a passage in the body extending transverse to the length of a terminal, the bar
engaging the terminal to prevent withdrawal. This prior proposal, which is not the
subject of an existing public disclosure proved to be impractical in arrangements
where the terminals, although extending parallel to one another, are not disposed
in a single straight row and do not have their planes parallel. For example connectors
for electromagnetic relays commonly have five blade reception socket terminals disposed
in a cruciform pattern with two of the terminals having their planes parallel but
at right angles to the planes of the remaining three terminals. To accommodate such
an arrangement a plurality of separately inserted and differently oriented, transversely
extending locking bars and associated passages would be required, and in addition
to the complexity of assembling the connector, the body moulding would be extremely
complex and therefore expensive to produce. It is an object of the present invention
to provide a connector having additional terminal locking in a simple and convenient
form.
[0004] A connector according to the invention includes a moulded synthetic resin body, a
plurality of parallel terminal receiving passages in the body, said passages being
open at one face of the body to permit insertion of the terminals into the passages
and having abutment surfaces to limit movement of the terminals in the passages in
the insertion direction, each of said passages having a shoulder intermediate the
ends thereof for engagement by a locking latch of the terminal to resist withdrawal
of the terminal, and each passage being open at an opposite face of the body to provide
access to said terminals whereby mating terminals can be introduced into said terminals
in use, the body having a plurality of locking bar passages extending into said body
parallel to said terminal receiving passages, each locking bar passage being positioned
adjacent a respective terminal receiving passage, and the connector including a plurality
of locking bars for insertion into respective locking bar passages, the arrangement
of the locking bars and the body being such that during insertion of the locking bars
co-action of each locking bar and the body generates a movement of part of the body
and/or the locking bar in a direction transverse to the locking bar insertion direction
to effect locking of the terminal of the respective terminal receiving passage against
withdrawal from the passage.
[0005] Preferably the wall of each terminal receiving passage includes a flexible resilient
region adjacent the respective locking bar passage, said region being moved, by insertion
of the respective locking bar, transversely from'a rest position clear of the terminal
of the respective terminal receiving passage, to a locking position in which the region
engages the terminal to resist withdrawal of the terminal from its passage.
[0006] Alternatively each locking bar passage and its respective terminal receiving passage
communicate such that upon insertion of the respective locking bar a portion of the
locking bar is deflected transversely to engage the respective terminal to resist
withdrawal of the terminal from its passage.
[0007] Preferably said locking bars are carried by a locking plate which engages said opposite
face of the body, said locking plate having apertures therein to provide access to
said terminal receiving passages.
[0008] Desirably said locking plate and locking bars are parts of a common component.
[0009] Preferably said locking plate is engaged as a snap fit with said body.
[0010] Conveniently said locking plate includes mounting means whereby the assembly of the
plate and body may be mounted on a support structure.
[0011] Desirably a plurality of locking plates and respective bars are formed as parts of
a common unit to which a plurality of respective connector bodies are coupled. Conveniently
the locking plate constitutes a mask for the connector body whereby common connector
bodies can be used in different applications, the connector bodies having terminal
receiving and locking bar passages to suit a variety of applications and the locking
plate having apertures associated with only those terminal receiving-passages which
are to be used for a particular application.
[0012] One example of the invention is illustrated in the accompanying drawings, wherein:-
Figure 1 is a side elevational view of the body of an electrical connector and mounting
block for an electromagnetic relay;
Figure 2 is a front elevational view (in the direction of arrow A in Figure 1) of
the body;
Figure 3 is a sectional view on the line 3-3 of Figure 2;
Figure 4 is a sectional view on the line 4-4 of Figure 2;
Figure 5 is a plan view of the locking arrangement of the connector body of Figure
1;
Figure 6 is a sectional view on the line 6-6 in Figure 5;
Figure 7 is a sectional- view on the line 7-7 of Figure 5;
Figure 8 is a repeat of Figure 2, but carrying different shading to identify different
passages of the body; and
Figure 9 is a diagrammatic view of the base of an electrical device to which connection
may be made by the connector of the previous views, Figure 9 showing in full lines
the normal electromagnetic relay terminal arrangement, and showing in dotted lines
the position of possible additional terminals where the device incorporates for example
a timer for use in achieving the intermittent wipe function of a windscreen wiper
system of a vehicle.
[0013] Referring to the drawings, the connector includes a moulded synthetic resin connector
body 11 of block-like form and a terminal locking member 12 also formed as a synthetic
resin moulding.
[0014] The connector body 11 is generally cubic including a pair of opposite faces 13, 14
which, hereinafter will be referred to as the upper and lower faces respectively.
Extending within the body 11 and open at both upper and lower faces 13, 14 are nine,
parallel, terminal receiving passages 15-23, the passages 15-19 being of larger width
than the remaining passages 20-23 since they are intended to receive larger terminals
than the passages 20-23. However, the terminals to be engaged in each of the passages
are of the same general type in the sense that they receive mating blade connectors
and are shown in broken lines in Figure 3. Thus each terminal 24 of the passages 15-19
is a flat socket terminal of the kind known as a LUCAR (Registered Trade Mark) including
a socket portion at one end and a lead connecting portion at the opposite end. Each
terminal of the passages 20-23 is smaller and -includes a socket portion having curved
fingers which grip the blade, and a lead connecting portion. The lead connecting portion
of each of the terminals 24 will, in use, be crimped around a respective conductive
lead or leads to achieve electrical connection between the terminal and the core of
the lead.
[0015] The lower face end of each of the passages 15-23 is open to permit insertion of the
respective terminals 24 from the lower face 14 of the body. The terminals are inserted
socket end first, and the upper face ends of the passages 15-23 are partially closed
thus defining internal abutments limiting the insertion movement of the terminals
24. The upper face ends of the passages are not completely closed since access must
be provided to the terminals 24 so that mating blade terminals 25 -(shown in broken
lines in Figure 3) of the device to which connection is to be made, can be introduced
into the socket terminals.
[0016] Partway along the length of the wall of each of the passages 15-23, each passage
wall is formed with a shoulder 26 facing towards the abutments at the upper face ends
of the passages, and against which a locking lance 27 of each terminal 24 can abut.
The locking lances 27 are of conventional form, and the arrangement is such that as
each terminal 24 is inserted into its respective passage the locking lance 27 thereof
is deflected inwardly, and, when the terminal is correctly positioned within its passage
the free end of the lance 27 aligns with the respective shoulder 26 and can spring
outwardly to lock behind the shoulder 26 and thus resist withdrawal of the terminal
from the passage.
[0017] The body 11 is formed with a further plurality of passages 28-36 (indicated by cross-hatching
in Figure 8) arranged to receive locking bars of the locking member 12. The passages
28-36 extend parallel to the passages 15-23 and each of the passages 28-36 is positioned
adjacent a respective one of the passages 15-23. A region of the wall which separates
each passage 15-23 from its respective passage 28-36 is shaped to define a flexible
resilient arm 37. The arms 37 extend lengthwise of the passages and are disposed in
the lower halves of their passages. Each arm 37 extends upwardly from the lower face
region of the respective passages and has its free end adjacent the transverse central
plane of the body. The inherent resilience of the arms 37 urges the arms 37 to a rest
position in which they are aligned with the length of their respective passages. The
arms can however be flexed in such a manner that they are inclined into their respective
passages 15-23, so that their free ends occupy a position beneath the socket portions
of their respective terminals 24. Clearly when the arms 37 are in this flexed position
then abutment between the lower end faces of the socket portions of the terminals
24 and the free ends of the arms 37 will prevent withdrawal of the terminals from
their passages.
[0018] It will have been noted from Figures 2 and 8 that there are four additional passages
within the body 11 extending parallel to the passages 15-23 and 28-36. These four
passages are not numbered in Figure 2, and are indicated by dotted shading in Figure
8. These passages do not serve a functional purpose during use of the connector and
are provided solely to equalize, so far as is possible, wall thicknesses within the
moulding to avoid uneven shrinkage during the cooling part of the moulding process.
[0019] The locking member 12 comprises a synthetic resin moulding in the form of a generally
rectangular locking plate 41 from one face of which project nine parallel locking
bars 42. The locking bars 42 are integral with the plate 41 and are arranged in the
same pattern as the locking bar passages 28-36 of the body. The cross- sectional shape
of each of the locking bars 42 corresponds to that of its respective locking bar passage
28-36 except that at its free end each of the locking bars 42 is tapered to define
a ramp surface 43 on one face thereof.
[0020] After introduction of the terminals 24 into the passages 15-23 the locking member
12 is engaged with the body 11 by inserting the locking bars 42 into the passages
28-36 from the upper face end of the passages 28-36. As the locking bars 42 are pushed
simultaneously into their passages 28-36 the ramp surfaces 43 of the locking bars
42 co-act with the arms 37, and deflect the arms 37 from their rest positions to their
operative positions so that the free ends of the arms 37 lock beneath the socket portions
of the terminals 24. When the bars 42 are fully inserted into their passages 28-36
the undersurface of the plate 41 abuts the upper face 13 of the body 11. In order
to provide access to the terminals 24 the plate 41 of the member 12 is provided with
appropriately positioned apertures 44. As is best seen in Figure 6 the apertures 44
are tapered from a maximum width at their outer end to provide a lead-in to guide
blade terminals of the device to which connection is to be made into the passages
15-23 to mate with the socket portions of the terminals 24.
[0021] Adjacent its four corners the plate 41 is provided with four integral flexible legs
45 two of which extend down one side face of the body 11 and the other two of which
extend down the opposite side face of the body 11 when the member 12 is fully engaged
with the body 11. Each of the legs 45 is formed with an aperture within which a respective
lug 46 on the sides of the body 11 is received. The lugs 46 include a ramp surface
on one end which deflects the respective leg 45 as the member 12 is engaged with the
body 11, the legs 45 then springing back to their original configuration to embrace
the lugs 46 within the apertures of the legs 45 when the full engagement position
of the member 12 on the body 11 is reached. Thus a snap action engagement of the member
12 with the body 11 is effected, but by virtue of a lack of ramp surface on the opposite
end of each lug 46 it is necessary manually to flex the legs 45 outwardly to permit
removal of the member 12.
[0022] In a first modification (not shown) the ramp surfaces 43 of the bars 42 are replaced
by equivalent ramp surfaces on the arms 37 or both the arms 37 and the bars 42 are
provided with co-acting ramp surfaces.
[0023] In a further modification (not shown) the arms 37 are dispensed with, and each passage
15-23 communicates with its respective passage 28-36 in such a manner that a locking
shoulder provided on each locking bar 42 can engage beneath the socket portion of
the respective terminal 24. During insertion of the locking bars 42 the locking bars,
at least at their free ends, are deflected transversley by ramps on the body and/or
bars, from their straight configuration so that when fully engaged with the body 11
the locking shoulders of the bars engage with the terminals to resist withdrawal.
It will be recognised that in each alternative construction the lengthwise movement
of the locking bars results, by virtue of a cam action, in transverse movement of
a part of the body or of the locking bar to engage the respective terminal.
[0024] Since the plate 41 has apertures 44 through which the terminals 25 pass to mate with
the terminals 24 then the plate 41 can be used as a mask permitting access only to
desired passages 15-23. It follows from this that a common body moulding can be produced
having passages to suit a wide variety of different applications, and each body 11-
will then be engaged with a specific locking member 12, the plate 41 of which will
contain only those apertures which are related to the application for which the connector
is intended.
[0025] Furthermore, it will be recognised that a plurality of locking members can be provided
as parts of a common moulding to which a number of bodies 11 can be attached. In this
way a single connector unit can be provided for a number of electrical devices and
moreover each separate locking member 12, or a multiple locking member can carry mounting
lugs or brackets whereby the connector can be secured to, for example a vehicle bulkhead.
[0026] Figure 9 illustrates diagrammatically the base of a conventional electromagnetic
relay wherein the five blade terminals 25a shown in solid lines represent the conventional
terminal layout. The four terminals 25b shown in dotted lines are indicative of additional
terminals one or more of which may be provided where the relay fulfils other functions.
The terminals 24 of the passages 20-23 are narrower and shorter in their socket portion
than are the terminals 24 of the passages 15-19. This dimensional difference is easily
accommodated in the locking action of the bars 42 by appropriate choice of length
for the relevant bars 42.
[0027] In each of the alternative arrangements described above, it will be recognised that
the terminals 24 will be retained in their respective passages 15-23 by their lances
27 and the shoulders 26 prior to engagement of the locking member 12. However, it
is found that on occasions the lances 27 are not adequate .to protect the terminals
against being pushed from their passages 15-23 in the withdrawal direction when a
terminal 25 is mated therewith. Thus the arms 37 in conjunction with the locking bars
42 or parts of the bars 42 themselves constitute a more positive locking arrangement
and have the added advantage that if the terminals 24 have not been inserted sufficient
far into their passages then the locking member 12 will not be capable of being fully
engaged with the body 11. It follows from this that the member 12 provides an immediate
visual check that the terminals 24 are fully inserted into their respective passages.
If it can be seen that the member 12 is fully engaged with the body 11, and is latched
in place by the legs 45, then the operator is assured that the terminals 24 are fully
home in their respective passages.
[0028] It will be understood that the use of the connectors described above is not restricted
to making of connections to electromagnetic relays and relay variants, and clearly
such connectors can be used with other electrical devices. Moreover, the use is not
restricted to connectors having flat socket type terminals, although it is particularly
advantageous with such terminals.
[0029] It is desirable to form the member 12 in a colour different from that of the body
11 so that it is apparent from even a cursory visual examination that the member 12
is in place.
1. An electrical connector comprising a moulded synthetic resin body (11), a plurality
of parallel terminal receiving passages (15-23) in the body, said passages being open
at one face (14) of the body to permit insertion of the terminals (24) into the passages
and having abutment surfaces to limit movement of the terminals in the passages in
the insertion direction, each of said passages having a shoulder (26) intermediate
the ends thereof for engagement by a locking latch (27) of the terminal to resist
withdrawal of the terminal, and each passage being open at an opposite face (13) of
the body to provide access to said terminals (24) whereby mating terminals (25) can
be introduced into said terminals (24) in use, characterized by the provision of a
plurality of locking bar passages (28-36) extending into said body (11) parallel to
said terminal receiving passages (15-23), each locking bar passage being positioned
adjacent a respective terminal receiving passage, and a plurality of locking bars
(42) for insertion into respective locking bar passages, the arrangement of the locking
bars (42) and the body (11) being such that during insertion of the locking bars co-action
of each locking bar and the body generates a movement of part (37) of the body and/or
the locking bar in a direction transverse to the locking bar insertion direction to
effect locking of the terminal of the respective terminal receiving passage against
withdrawal from the passage.
2. An electrical connector as claimed in claim 1, characterized in that the wall of
each terminal receiving passage includes a flexible resilient region (37) adjacent
the respective locking bar passage, said region (37) being moved, by insertion of
the respective locking bar (42), transversely from a rest position clear of the terminal
(24) of the respective terminal receiving passage, to a locking position in which
the region engages the terminal to resist withdrawal of the terminal from its passage.
3. An electrical connector as claimed in any one of claims 1 to 3, characterized in
that each locking bar passage and its respective terminal receiving passage communicate
such that upon insertion of the respective locking bar a portion of the locking bar
is deflected transversely to engage the respective terminal to resist withdrawal of
the terminal from its passage.
4. An electrical connector as claimed in claim 1, characterized in that said locking
bars are carried by a locking plate (41) which engages said opposite face (13) of
the body, said locking plate (41) having apertures (44) therein to provide access
to said terminal receiving passages.
5. An electrical connector as claimed in claim 4, characterized in that said locking
plate (41) and locking bars (42) are parts of a common component (12).
6. An electrical connector as claimed in claim 4 or claim 5, characterized in that
said locking plate (41) is engaged as a snap fit with said body (11).
7. An electrical connector as claimed in any one of claims 4 to 6, characterized in
that said locking plate includes mounting means whereby the assembly of the plate
(41) and body (11) may be mounted on a support structure.
8. An electrical connector as claimed in claims 4 to 7, characterized in that a plurality
of locking plates (11) and respective bars (42) are formed as parts of a common unit
to which a plurality of respective connector bodies (11) are coupled.
9. An electrical connector as claimed in claims 4 to 8, characterized in that the
locking plate constitutes a mask for the connector body (11) whereby common connector
bodies can be used in different applications, the connector bodies having terminal
receiving and locking bar passages to suit a variety of applications and the locking
plate (41) having apertures (44) associated with only those terminal receiving passages
which are to be used for a particular application.