GB1570189A

GB1570189A - Electric connectors

Info

Publication number: GB1570189A
Application number: GB4014/76A
Authority: GB
Original assignee: BICC Burndy Ltd
Current assignee: BICC Burndy Ltd
Priority date: 1977-02-02
Filing date: 1977-02-02
Publication date: 1980-06-25
Also published as: GB1570190A

Description

(54) IMPROVEMENTS IN ELECTRIC CONNECTORS (71) We, BICC-BURNDY LIMITED, a British Company, of Parr, St. Helen, Merseyside, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly desin and by the following statement: This invention relates to electric connectors and especially, but not exclusively, to multicontact connectors for engaging a series of contacts arranged in a straight row, for example contacts formed on an edge of a printed circuit board and to a method of making an electrical connection by means of one of the connectors.

Usually the contacts of such a connector must engage the slides, rather than the end, of the contact and, especially with connectors of small size, it is difficult to ensure good contact pressure without requiring a high insertion force and so risking deformation and damage to contacts during insertion.

In accordance with the invention, an electric connector includes an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at least one contact element is located in the space between the stiff insulating members and includes a contact portion that lies close to one of the stiff insulating members and is spaced from the other, being at a place spaced from the bridge or bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.

Preferably the contact, or each contact, if there is more than one, includes two of the contact portions referred to, lying close to each of the stiff insulating members and facing one another with a gap between them.

The invention includes a method of making an electrical connection in which a contact to which coinnection is to be made is inserted into the gap just referred to, or if the contact element in question has only one contact portion, into the gap between the contact portion and the stiff insulating member from which it is spaced, and then the wedging member is engaged with the stiff insulating members to urge them apart where it contacts them and so to bend the bridge or bridges and urge the stiff insulating members towards one another on the opposite side thereof and so to urge the contact portion or both the contact portions into firm engagement with the contact to which connection is to be made.

The insulating body may be of any plastics material of appropriate- resilience; nylon and polypropylene are often preferred. It will be apparent that the bridge or bridges must be capable of resisting compressive forces though they need to bend fairly easily.

Preferably the wedging member is integral with the insulating body. Preferably it is joined to one of the stiff insulating members by an integral hinge, but it could alternatively be connected to one or both of them by a flexible strap or flexible straps.

In connectors with more than one contact element, the bridges may sometimes be sufficient to ensure proper lateral spacing of the contacts, but in most cases it is desirable to provide suitable abutments (for example ridges extending in a front-to-rear direction) on the face of at least one of the stiff insulating members that faces the other.

Abutments facing towards the front and/or rear of the connector may be provided to locate and secure the contact elements in any appropriate way.

In most cases the contact portions of the contact elements will be located between the bridge or bridges and the front of the connector (through which the contacts to which connection is to be made enter), and the wedging member will engage the rear end of the insulating body, but if desired the contact(s) may extend through the insulating body to a contact zone beyond the bridge or bridges, and in this case the wedging mem ber would engage the front end of the body.

When a contact element serves to connect its contact to a wire or cable, the contact preferably includes a crimping socket (or "bucket"), for receiving the wire or cable, that extends in the same direction as the part of the contact element that receives the contact and the contact element is designed for insertion from the rear of the insulating body.

Preferably the socket is designed (in accordance with our copending Application No. 1700/77 serial no. 1,570,190 for crimping by tools moving in a direction parallel to the direction of movement of the contact portion(s) when the wedge is engaged; in the case of a multicontact connector this simplifies assembly and termination, as the contact elements can be prepared initially from sheet metal with connecting bridges or "selvages" and partly or wholly assembled with the insulating body prior to crimping the wires or cables to them (in some cases in a single operation for all the wires or cable conductors) and cutting to separate individual contact elements.

The invention will be further described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a longitudinal cross-section of a preferred form of connector in accordance with the invention; Figure 2 is a cut-away plan view of a part of the connector; Figure 3 is a portion of the cross-section on the line III--III in figure 1; Figure 4 is a diagrammatic isometric projection of the same connector showing two contact units only; Figure 5 is a longitudinal cross-section of the housing only of an alternative form of connector; Figure 6 is a front view of the housing shown in figure 5; Figure 7 is an end view and Figure 8 a side view of a preferred design of contact for either of the connectors, and Figure 9 shows a blank for the contact shown in figures 7 and 8.

The connector of figures 1 includes an insulating body 1 made up of an upper member 2 and a lower member 3 which are stiff enough to be substantially rigid under conditions of use (in figure 2, the upper member 2 is ommited to show the internal structure more clearly). The upper and lower members 2 and 3 are connected together only by integral flexible but resilient bridges 4 (not visible in figure 1).

In alignment with the bridges 4 the upper and lower members are formed with ridges 5 to form between them a series of basically rectangular passages each of which receives a contact element 6. The contact elements will be more fully described below, but they consist basically of upper and lower contact portions.7, 8 respectively, which bear on or lie close to the upper and lower walls of the contact passages, and a crimping socket 9.

The contact element is inserted from the rear of the housing, that is the left-hand end as seen in figures 1 and 2, and is prevented from passing completely through the passage by abutments 10 near the front of :the housing. A shoulder 11, formed by the end of a slot 12 extending from the front of the housing, engages a resilient detent 13 to prevent unintentional withdrawl of the element; a releasing tool can be introduced through the slot 12. if required, to release the detent 13.

A wedging member 14 is flexibly connected to the lower body member 3 by an integral hinge 15. When a connection is to be made, this wedging member is arranged in the position shown in broken lines in figure 1, in which it exerts no appreciable force on, and will not necessarily touch, the upper body member 2. A printed-circuit board 16 or other contact to be engaged can then be inserted between the contact portions 7 and 8 without requiring any significant insertion force. The wedging member 14 is now brought to the position shown in solid lines in which it engages the contiguous rear end 17 of the upper member 2 and forces it away from the lower member 3, thereby flexing the bridges 4 and causing the front ends 18, 19 of the upper and lower body members to approach one another, thereby squeezing the contact portions 7, 8 between them and increasing the contact pressure to an acceptable value. To withdraw the board 16 or other contact, the wedging member is first returned to the release position shown in broken lines, so that withdrawl also requires no substantial force. By avoiding large insertion and withdrawl forces the risk of damaging contacts is considerably reduced.

The alternative design shown in figures 5 and 6 incorporates two independent modifications (either of which can be used separately). First, the wedging member 20 is separate from the body 1, and the rear end parts 21, 22 of the upper and lower members 2, 3 are alike; this simplifies manufacture but has the disadvantage that the wedge member may be forgotten during the initial stages of assembly. Secondly the slot 12 (Figures 14) replaced by an aperture 23 of square or other suitable cross-section opening to the top of the housing.

Figures 7-9 ilustrate a preferred design of contact element for either of the connectors described. This is formed from sheet metal by conventional techniques. The contact portions 7 and 8 and crimping socket 9 have already been briefly referred to.

The contact portions 7 and 8 are alike and are each pressed to form stiffening sidewalls 24, a tapered lead-in zone 25, and a contact dimple 26. The contact portions are connected by flexible arms 27, 28 to a channel section central support 29, one limb of which provides the resilient detent 13 already described. The crimping socket 9 is of the opensided type and includes a contact-making section 30 for engaging the bare end of an insulated wire and a gripping section 31 for engaging the insulation remaining on the wire. Figure 9 shows the blank from which the contact element is to be made, as initially stamped out but before pressing and bending; the reference numerals in this figure correspond (where applicable) to the parts of the element that will be formed by the various parts of the blank. The blanks are connected together for ease of handling by "selvages" 32, 33 for as long as possible, and in suitable cases the selvege 32 may be retained until the contact has been at least partly inserted in the housing (whereupon the housing may provide the desirable support).

In accordance with our Application No.

1700/77 (Serial No. 1,570,190), and as more fully explained in the complete specification of that application, the direction of flexing of the arms 27 associated with the transmission of contact pressure to the dimples 26 and the printed circuit board between them lies in the plane of figure 8 and the direction of movement of the two dies used to crimp the socket 9 also lies in the plane of this figure.

WHAT WE CLAIM IS:- 1. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at least one contact element located in the space between the stiff insulating members and including a contact portion that lies close to one of the stiff insulating members and is spaced from the other, being at a place spaced from the bridge or bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.

2. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at least one contact element located in the space between the stiff insulating members and including two contact portions that lie close to respective ones of the stiff insulating members and are spaced from each other, being at a place spaced from the bridge or bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.

3 An electric connector for engaging a series of contacts arranged in a straight row comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by resilient bridges located between and spacedfrom both of, the front and rear of the body; a straight row of contact elements located in the space between the stiff insulating members and each including a contact portion that lies close to one of the stiff insulating members and spaced from the other, being at a place spread from the bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridges from the places just referred to.

4. An electric connector for engaging a series of contacts arranged in a straight row comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by resilient bridges located between, and spaced from both of, the front and rear of the body; a straight row of contact elements located in the space between the stiff insulating members and each including two contact portions that lie close to respective ones of the stiff insulating members and are spaced from each other at a place spaced from the bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridges from the places just referred to.

5. A connector as claimed in claim 3 or claim 4 having abutments on the face of at least one of the stiff insulating members that faces the other to ensure proper lateral spacing of the contacts.

6. A connector as claimed in claim 5 in which the abutments are ridges extending in a front-to-rear direction.

7. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at leaset one contact element located in the space between the stiff insulating members and including a contact portion that lies close to one of the stiff insulating members and is spaced from the other at a place spaced from the bridge or bridges; and a wedging member integral with the insulating body and engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

are each pressed to form stiffening sidewalls 24, a tapered lead-in zone 25, and a contact dimple 26. The contact portions are connected by flexible arms 27, 28 to a channel section central support 29, one limb of which provides the resilient detent 13 already described. The crimping socket 9 is of the opensided type and includes a contact-making section 30 for engaging the bare end of an insulated wire and a gripping section 31 for engaging the insulation remaining on the wire. Figure 9 shows the blank from which the contact element is to be made, as initially stamped out but before pressing and bending; the reference numerals in this figure correspond (where applicable) to the parts of the element that will be formed by the various parts of the blank. The blanks are connected together for ease of handling by "selvages" 32, 33 for as long as possible, and in suitable cases the selvege 32 may be retained until the contact has been at least partly inserted in the housing (whereupon the housing may provide the desirable support).

In accordance with our Application No.

1700/77 (Serial No. 1,570,190), and as more fully explained in the complete specification of that application, the direction of flexing of the arms 27 associated with the transmission of contact pressure to the dimples 26 and the printed circuit board between them lies in the plane of figure 8 and the direction of movement of the two dies used to crimp the socket 9 also lies in the plane of this figure.

WHAT WE CLAIM IS:- 1. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at least one contact element located in the space between the stiff insulating members and including a contact portion that lies close to one of the stiff insulating members and is spaced from the other, being at a place spaced from the bridge or bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.
2. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at least one contact element located in the space between the stiff insulating members and including two contact portions that lie close to respective ones of the stiff insulating members and are spaced from each other, being at a place spaced from the bridge or bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.
3 An electric connector for engaging a series of contacts arranged in a straight row comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by resilient bridges located between and spacedfrom both of, the front and rear of the body; a straight row of contact elements located in the space between the stiff insulating members and each including a contact portion that lies close to one of the stiff insulating members and spaced from the other, being at a place spread from the bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridges from the places just referred to.
4. An electric connector for engaging a series of contacts arranged in a straight row comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by resilient bridges located between, and spaced from both of, the front and rear of the body; a straight row of contact elements located in the space between the stiff insulating members and each including two contact portions that lie close to respective ones of the stiff insulating members and are spaced from each other at a place spaced from the bridges; and a wedging member engageable between the two stiff insulating members on the opposite side of the bridges from the places just referred to.
5. A connector as claimed in claim 3 or claim 4 having abutments on the face of at least one of the stiff insulating members that faces the other to ensure proper lateral spacing of the contacts.
6. A connector as claimed in claim 5 in which the abutments are ridges extending in a front-to-rear direction.
7. An electric connector comprising: an insulating body comprising two stiff members facing one another across a space and connected together only by a resilient bridge or bridges located between, and spaced from both of, the front and rear of the body; at leaset one contact element located in the space between the stiff insulating members and including a contact portion that lies close to one of the stiff insulating members and is spaced from the other at a place spaced from the bridge or bridges; and a wedging member integral with the insulating body and engageable between the two stiff insulating members on the opposite side of the bridge or bridges from the place just referred to.
8. A connector as claimed in any one of

claims 24 in which the wedging member is integral with the insulating body.
9. A connector as claimed in claim 7 or claims 8 in which the wedging member is jointed to one of the stiff insulating members by an integral hinge.
10. A connector as claimed in claim 7 or claim 8 in which the wedging member is connected to one or both the stiff insulating members by a flexible strap or flexible straps.
11 A connector as claimed in any one of the preceding claims in which the insulating body is made of nylon or of polypropylene.
12. A connector substantially as described with reference to figures 1-4 of the drawings and as shown in figures 1-3.
13. A connector substantially as described with reference to figures 5 and 6 of the drawings.
14. A connector substantially as described with reference to figures 7-9 and either figures 1 or figures 5 and 6 of the drawings.
15. A method of making an electrical connection by means of a connector claimed in any one of the preceding claims com- prising inserting a contact to which connection is to be made between the two contact portions of the contact element (or one of the contact elements) or, if the contact element in question has only one contact portion, between that contact portion and the stiff insulating member from which it is spaced, and then engaging the wedging member with the stiff insulating members to urge them apart where it contacts them and so to bend the bridge or bridges and urge the stiff insulating members towards one another on the opposite side thereof and so to urge the contact portion or both the contact portions into firm engagement with the contact to which connection is to made.