WO2008084275A2

WO2008084275A2 - Improved solderless wire termination assembly

Info

Publication number: WO2008084275A2
Application number: PCT/IB2006/055066
Authority: WO
Inventors: B.L.F Paagman; Ludwig Lange
Original assignee: Fci
Priority date: 2006-12-29
Filing date: 2006-12-29
Publication date: 2008-07-17
Also published as: WO2008084275A3

Abstract

The invention relates to a solderless wire termination assembly (2) comprising a housing (12, 13) and at least one contact (15) accommodated in said housing. The contact comprises a first contact beam (17) and a second contact beam (18) defining a wire termination region (19). The wire termination assembly further comprises clamping means (20) capable of interacting with at least one of said first contact beam and second contact beam for clamping of a wire (5) in said wire termination region. The cooperation of the operable clamping means with (parts of) the contacts allows for a reliable fixation of the wires in the contacts.

Description

IMPROVED SOLDERLESS WIRE TERMINATION ASSEMBLY

FIELD OF THE INVENTION

Generally, the invention relates to the field of electrical connectors. More specifically, the invention relates to the field of terminating electrical wires in contacts for manu- facturing e.g. a cable connector.

BACKGROUND OF THE INVENTION

Electrical cable connectors are applied in a variety of industrial field, including automotive industry and the telecom- munication industry. Typically, one or more cables are attached to a cable connector for the transmission of electrical signals over the wires of these cables. To that end, the wires should be terminated in the cable connector.

There is a trend towards the use of small circuit boards, such as printed circuit boards (PCB' s) for termination of these wires in an electrical connector. An example of such a cable connector is disclosed in WO 2004/057707 of the applicant.

Terminating the wires to the PCB with conventional methods such as using IDC termination or soldering may be not suitable here. Considering the small dimensions of the PCB, the dimensions of IDC terminals may be too large, whereas soldering wires on a PCB with a small pitch is difficult.

SUMMARY OF THE INVENTION A solderless wire termination assembly is proposed that comprises a housing and at least one contact accommodated in said housing. The contact comprises a first contact beam and a second contact beam defining a wire termination region. The wire termination assembly further comprises clamping means capable of interacting with at least one of said first contact beam and second contact beam for clamping of a wire in said wire termination region.

Furthermore, a solderless wire termination assembly is proposed that comprises a circuit board with a plurality of con- tact pads. The assembly comprises at least one housing mounted on said circuit board and clamping means. A plurality of contacts, accommodated in said housing and connected to corresponding contact pads of said circuit board are provided. At least one of said contacts comprises a first contact beam and a second contact beam defining a wire termination region . The clamping means are capable of interacting with at least one of said first contact beam and second contact beam for clamping of a wire in said wire termination region. Moreover, a solderless wire termination assembly is proposed that comprises a circuit board with a plurality of contact pads. A housing is mounted on said circuit board and comprises a lid. The lid is hingeably arranged in said housing. A plurality of contacts is accommodated in the housing. At least one contact pad is connected to a first contact comprising a first contact beam and a second contact beam and connected to a second contact comprising a third contact beam and a fourth contact beam. The first to fourth contact beams define a wire termination region. The lid is arranged to interact with said first and third contact beam in a closed position of said lid for clamping of a wire in said wire termination region.

The proposed solderless wire termination assembly facilitates termination of wires, since the wires can be introduced in the wire termination region without requiring a substantial insertion force. After introduction of the wires in the wire termination region as defined by the contacts, the clamping means are operated to clamp the wires in the wire termination region. The application of solder is not required. The cooperation of the operable clamping means with (parts of) the contacts allows for a reliable fixation and an appropriate electrical contact of the wires in the contacts. The contacts that cooperate with the clamping means can be manufactured sufficiently small to allow implementation on a printed circuit board, whereas the application techniques for mounting of these contacts on contact pads of the circuit board are readily available. By using two contacts for each contact pad, a suitable guiding means is provided for guiding the wire within the wire termination region. These types of contacts may e.g. comprise contacts that are typically used for flex-foil termination.

The embodiments of the invention as defined in claims 2 and 3 provide for a contact that is capable of guiding the wire on introduction in the wire termination region.

The embodiment of the invention as defined in claim 4 allows for the termination of a plurality of wires in corresponding contacts on a circuit board.

The embodiment of the invention as defined in claim 5 increases the amount of wires that can be terminated on a single circuit board.

The embodiment of the invention as defined in claim 6 facilitates manufacturing of a cable connector comprising one or more wire termination assemblies. The embodiments of the invention as defined in claims 7 and 8 provide a convenient clamping means that can be integrated in the housing. The hingeable lid allows the introduction of a plurality of the wires in the wire termination regions as defined by the contacts combined with a single clamping operation for all introduced wires by closing the lid.

The embodiment of the invention as defined in claim 9 allows for the introduction of wires with a small diameter, e.g. smaller than 0,4 mm. These wires do not possess sufficient stiffness to overcome a substantial insertion force in a termi- nation contact.

The invention also relates to a cable connector comprising a solderless wire termination assembly as proposed above, as well as a kit of parts comprising a cable connector and a wire termination assembly and a method for terminating wires in a solderless wire termination assembly.

It should be noted that the above aspects and embodiments may be combined.

The invention will be further illustrated with reference to the attached drawings, which schematically show preferred embodiments according to the invention. It will be understood that the invention is not in any way restricted to these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a schematic illustration of a cable connector according to an embodiment of the invention; FIGS. 2A and 2B show an overview and a detail of a solderless wire termination assembly according to an embodiment of the invention;

FIGS. 3A and 3B show an overview and a detail of the assembly of FIGS. 2A and 2B without the clamping means; FIGS. 4A and 4B show details of the contacts of the assembly of FIGS. 2A and 2B containing wires without the housings, and

FIGS. 5A-5C show schematic illustrations for different embodiments of one or more contacts for termination of a wire.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic illustration of a cable connector 1 comprising a plurality of solderless wire termination assemblies 2, hereinafter also referred to as termination assem- blies 2, in a housing 3 of the cable connector 1. A cable 4 having round wires 5 enters the housing 3 of the cable connector 1. In FIG. 1 only a single wire 5 is shown as an example. An exemplary wire 5 has a diameter of e.g. 0,3 mm. It should be noted that the function of the wire termination assemblies 2 is only to reliably terminate the wires 5 in the cable connector 1. The cable 4 is mounted in the housing 3 such that pull relief and twist relief for absorption of forces exerted on the cable 4 are provided by structures in the housing 3 of the cable connector 1. The housing 3 of the cable connector 1 has a receiving struc- ture 6 for positioning and/or fixation of the termination assemblies 2 in the housing 3.

FIGS. 2A-2B, 3A-3B and 4A-4B depict various aspects of a solderless wire termination assembly 2 for the cable connector 1 according to an embodiment of the invention. In this embodi- ment, the wires 5 are provided with a wire jacket or sheath that is stripped partially to expose the core of the wire 5 for ter- mination of the wire 5. The wires are provided at a small pitch and may adjoin each other.

The termination assembly 2 comprises a circuit board 10 containing a plurality of contact pads 11. A first housing 12 is provided on a first side of the circuit board 10 and a second housing 13 is provided on the opposite side of the circuit board 10. The housings 12, 13 are mounted on the circuit board by means of surface mount technology (SMT) using a solder reflow process. The primary purpose of the circuit board 10 is simply to interconnect signals received at the contact pads 11 to further contact pads 14 on the opposite end of the circuit board 10. Of course, the circuit board 10 may comprise components (not shown in the FIGS.), such as, signal processing components, filters or amplifiers. Obviously, the circuit board 10 may also carry only a single housing 12 for accommodating the termination contacts for the wires 5.

Each of the housings 12, 13 accommodates a plurality of contacts 15 for termination of the wires 5. The housings 12, 13 limit the sideway movement (in the drawings: the horizontal di- rection) of the contacts 15. In the embodiment shown, two contacts 15 are connected to each single contact pad 11. It should be appreciated that, as will be clarified with reference to FIGS. 5A-5C, that other embodiments for the contacts 15 have been envisaged by the applicant. Each contact 15 comprises a connection portion 16 for connection to the contact pad 11 of the circuit board 10, a first contact beam 17 and a second contact beam 18. The first and second contact beam 17, 18 of both contacts together define a wire termination region 19 where the wire 5 can be clamped, as is most clearly visible in FIGS. 4A and 4B.

The first contact beam 17 is longer than the second contact beam 18. Therefore, the flexibility of the first contact beam 17 is larger than the flexibility of the second contact beam 18. The first contact beam 17 comprises a step in order to define an appropriate entrance for introduction of the wire 5 in the wire termination region 19. The second contact beam 18 has a protruding structure 18A for developing an appropriate retention force with a wire 5.

Whereas the contacts 15 in the depicted embodiment are identical, it should be appreciated that the contacts may also differ from each other in shape, structure and/or material.

The housings 12, 13 are structured to comprise a clamping means 20 capable of interacting with the first contact beams 17 of the contacts 15 for clamping of a wire 5 in the wire termination region 19. As clearly visible in FIGS. 2A and 2B, the clamping means comprises a lid or cover hingeably arranged in the housing 12.

In operation, a plurality of wires 5 are introduced in the wire termination regions 19 defined by the contacts 15. In this phase, the lid 20 is in an open position (not shown) and the contacts 15 are in a receiving state.

For the embodiments shown on FIGS. 2A, 2B ; 3A, 3B ; 4A, 4B, two contacts 15 are available for each wire 5. Both contacts 15 are connected to a single contact pad 11 of the circuit board 10. The contacts 15 are positioned on the contact pad 11 such that a gap exists between these contacts 15. This position of the contacts 15 provides for guiding of the wire 5 in the wire termination region 19. For the case of FIGS. 4A-4B, the first beams 17 and second beams 18 of the two contacts 15 develop four line contacts during introduction of the wire 5. The introduction of the wires in the wire termination region 19 does not require a relevant insertion force, i.e. the contacts 15 are zero-insertion-force contacts (ZIF-contacts) . The use of ZIF contacts is advantageous since the diameter of the wires 5 is typically small and the wires 5, therefore, do not possess suf- ficient stiffness to cope with axial forces on the wire 5 without bending.

When the wires 5 are in the appropriate position in the wire termination region 19, the clamping means 20 is closed. This situation is shown in FIGS. 2A and 2B. During closing of the clamping means 20, the clamping means 20 develops a direct force on the first beams 17 of the contacts 15 to clamp the wires 5 in the wire termination region 19. The first beams 17 of the contacts 15 deform elastically as a result of the interaction with the clamping means 20. The clamping force F on the first contact beams 17 is transferred to the wires 5 and further to the second contact beams 18. Since the flexibility of the second contact beams 18 is less than the flexibility of the first contact beams 17, the second contact beams 18 determine the contact force between the contact 15 and the wire 5. The protruding structure 18A of the second contact beam 18 provides for a high retention force. The second contact beam 18 may be supported by the housing 12, but this is not necessary. The clamping means 20 and housing 12 are structured such that the lid may be kept in the closed position as long as desired and without requiring manual interaction with the lid.

The circuit board 10 comprises receiving structures 21 capable of cooperating with the receiving structure 6 of the cable connector 1 for positioning and/or fixation of one or more termination assemblies 2 in the housing 3 of the cable connector 1.

In summary, the contacts 15 are ZIF contacts that can be positioned closely to each other and allow easy insertion and appropriate electrical contact of wires 5 in wire termination regions 19 of these contacts 15. The wires 5 are caught in the wire termination regions 19 by closing the clamping means 20. Consequently, a convenient assembly and method are provided for easy, fast, sufficient and relatively inexpensive termination of wires at a small pitch that does not require any dedicated tool and thus is field-installable and field-repairable.

It should be appreciated that the invention is not limited to the embodiment shown in FIGS. 2A-2B, 3A-3B and 4A-4B. In particular, various structures, shapes and configurations may be used for the contacts 15 and clamping means 20. Some of such alternative contacts 15 and clamping means 20 are schematically illustrated in FIGS. 5A-5C. In FIGS. 5A-5C, the wire 5 is schematically illustrated by the dashed circle. In FIG. 5A, a single contact 15 is provided, wherein the wire termination region 19 is defined between the first and second contact beam 17, 18. The clamping means 20 is capable of interacting with the first contact beam 17 for clamping the wire 5 in the wire termination region 19.

In FIG. 5B, a contact 15 is provided comprising two first contact beams 17 and a single second contact beam 18. The two first contact beams 17 and the second contact beam 18 define a wire termination region 19 where the wire 5 can be clamped. A combined clamping means 20 is capable of interacting with both first contact beams 17 for clamping the wire 5 in the wire termination region 19. In FIG. 5C, two contacts 15 are provided in correspondence with the embodiment of FIGS. 2A-2B, 3A-3B and 4A-4B. But in contrast with a single lid, the clamping means 20 in the schematic embodiment of FIG. 5C are capable of interacting with both first contact beams 17 independently from each other. Finally, it should be appreciated that sideway movement of the wires 5 may be limited by alternative means, such as the housings 12, 13 or the shape of the contacts 15. This is particularly true for the embodiment of FIG. 5A, that provides for a rather instable position of the wire 5.

Claims

1. A solderless wire termination assembly (2) comprising a housing (12,13) and at least one contact (15) accommodated in said housing, wherein said contact comprises a first contact beam (17) and a second contact beam (18) defining a wire termi- nation region (19) and wherein said wire termination assembly further comprises clamping means (20) capable of interacting with at least one of said first contact beam and second contact beam for clamping of a wire (5) in said wire termination region.

2. The solderless wire termination assembly (2) accord- ing to claim 1, wherein said wire termination assembly comprises two contacts (15), each comprising a first contact beam (17) and a second contact beam (18), said first contact beams and second contact beams defining said wire termination region (19), and wherein said clamping means (20) are capable of interacting with at least one of said first contact beams and second contact beams for clamping said wire (5) in said wire termination region .

3. The solderless wire termination assembly (2) according to claim 2, wherein said two contacts (15) are connected to a single contact pad (11) of a circuit board (10) .

4. The solderless wire termination assembly (2) according to one or more of the preceding claims, wherein said wire termination assembly further comprises a circuit board (10) with a plurality of contact pads (11), and wherein said housing (12,13) is mounted on said circuit board and a plurality of said contacts (15) are connected to corresponding pads of said plurality of contact pads.

5. The solderless wire termination assembly (2) according to claim 4, wherein said housing (12) is mounted on one side of said circuit board (10) and a further housing (13) accommodating contacts (15) is mounted on an opposite side of said circuit board.

6. The solderless wire termination assembly (2) according to claim 4 or 5, wherein said circuit board (10) comprises at least one receiving structure (21) capable of positioning said wire termination assembly in a cable connector housing (3) .

7. The solderless wire termination assembly (2) according to one or more of the preceding claims, wherein said housing (12, 13) comprises a lid (20) capable of interacting with said first contact beam (17) in a closed position of said lid.

8. The solderless wire termination assembly (2) according to claim 7, wherein said lid (20) is hingeably arranged in said housing.

9. The solderless wire termination assembly (2) according to one or more of the preceding claims, wherein said at least one contact (15) is a zero insertion force contact.

10. The solderless wire termination assembly (2) according to one or more of the preceding claims, wherein said wire termination region (19) is capable of receiving wires (5) with a diameter of maximum 0,4 mm.

11. A solderless wire termination assembly (2) comprising :

- a circuit board (10) comprising a plurality of con- tact pads (11) ;

- at least one housing (12,13) mounted on said circuit board, wherein said housing further comprises clamping means

(20);

- a plurality of contacts (15), accommodated in said housing and connected to corresponding contact pads of said circuit board, wherein at least one of said contacts comprises a first contact beam (17) and a second contact beam (18) defining a wire termination region (19) and wherein said clamping means are capable of interacting with at least one of said first contact beam and second contact beam for clamping of a wire (5) in said wire termination region.

12. A solderless wire termination assembly (2) comprising : - a circuit board (10) comprising a plurality of contact pads (11) ; - at least one housing (12,13) mounted on said circuit board and comprising a lid (20), said lid being hingeably arranged in said housing;

- a plurality of contacts (15), accommodated in said housing, wherein at least one contact pad is connected to two contacts (15), each comprising a first contact beam (17) and a second contact beam (18), said first contact beams and second contact beams defining a wire termination region (19) and wherein said lid is arranged to interact with said first contact beams in a closed position of said lid for clamping of a wire (5) in said wire termination region.

13. A cable connector (1) comprising one or more solderless wire termination assemblies (2) according to one or more of the claims 1-12 and a cable connector housing (3) accommodating said one or more solderless wire termination assemblies .

14. The cable connector according to claim 13, wherein said cable connector housing (3) comprises receiving structures (6) capable of receiving a plurality of said solderless wire termination assemblies (2).

15. A kit of parts comprising:

- a cable connector housing (3) comprising a receiving structure (6) for receiving at least one solderless wire termi- nation assembly (2) according to one or more of the claims 1-12, and

- one or more of said solderless wire termination assemblies .

16. A method of terminating a wire (5) in a solderless wire termination assembly (2) according to one or more of the claims 1-12, said method comprising the steps of:

- introducing said wire in said wire termination region (19) of said contact or contacts (15) without applying an insertion force; - operating said clamping means (20) for clamping said wire in said wire termination region.