ELECTRICAL CONNECTORS

Abstract: An electrical connector comprising a moulded synthetic resin body (11), a plurality of parallel terminal receiving pas­ sages (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) inter­ mediate 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 ter­ minals (25) can be introduced into said terminals (24) in use, the body having a plurality of locking bar passages (28-36) extending into said body parallel to said terminal receiving passages, each locking bar passage being positioned adja­ cent a respective terminal receiving passage, and plurality of locking bars (42) for insertion into respective locking bar pas­ sages, 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 (37) of the body 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.

Description: 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. It is known to provide a connector comprising a blocklike 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. 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. 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. 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 barv 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. 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. 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. Desirably said locking plate and locking bars are parts of a common component. Preferably said locking plate is engaged as a snap fit with said body. Conveniently said locking plate includes mounting means whereby the assembly of the plate and body may be mounted on a support structure. 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. 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. 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. 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. 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. 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. 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. It will have been noted from Figures 2 and S 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. 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 crosssectional 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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.

Claims: CLAIMS: 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.

Inventors: HAYES, ALAN
Applicants: LUCAS INDUSTRIES PUBLIC LIMITED COMPANY
Application year: 1984
Main classification: H01R13
IPC codes: H01R13