WO2004084357A1

WO2004084357A1 - Connector device

Info

Publication number: WO2004084357A1
Application number: PCT/SE2003/001969
Authority: WO
Inventors: Daniel Ragnarsson
Original assignee: Plastab I Anderstorp Ab
Priority date: 2002-09-25
Filing date: 2003-12-17
Publication date: 2004-09-30
Also published as: SE0202818D0; AU2003287142A1; SE0202818L; SE522577C2

Abstract

A connector device (1) comprises a connector housing (2) in which is disposed at least one terminal finger (9) and a spring member (10) associated with the terminal finger (9). The spring member (10) realises requisite contact pressure between two terminal fingers (9) on interconnection of two connector devices (1) and also realises a positioning and fixing of the terminal finger (9) in the axial direction of the connector housing (2). The spring member (10) is of one piece manufacture with the connector housing (2).

Description

CONNECTOR DEVICE

TECHNICAL FIELD

The present invention relates to a connector device comprising a connector housing in which is disposed at least one terminal finger and a spring member associated with the terminal fmger for realising requisite contact pressure between two terminal fingers on interconnection of two connector devices.

The present invention also relates to a connector device where the spring member realises a positioning and fixing of the terminal finger in the axial direction of the connector housing.

BACKGROUND ART

Connector devices are previously known in the art, in particular for high current intensities, the connector devices being intended to be connected to the end of a cable, for interconnecting one or more cables to each other. The connector devices comprise an outer housing, typically manufactured from plastic, terminal fingers for the actual electric connection, as well as a metal spring associated with each terminal finger in order to realise such a force on each respective terminal fmger that, in the connected position, they are urged against one another for maintaining good contact whereby sparking or undesirable overheating because of unsatisfactory contact between the terminal fingers is avoided.

The spring also acts to position the terminal fmger correctly in the connector housing and to keep it in this position even when two connector devices are connected to one another or are separated. Since it is a matter of importance that the contact area between two connected terminal fingers should be as large as possible, it is crucial that the positioning be as exact as possible and that this position is maintained even if the forces which act axially on the terminal fingers on connection and disconnection are great. The connected cables also entail an action on the terminal fingers since they are both heavy and stiff and, as a result, in particular in movement of the connector device, generate both axial and transverse forces on the terminal fingers. The fit between each respective terminal finger and connector housing must, in such instance, be very good since play between the two terminal fingers in high current intensities may, for example, cause severe overheating. The ideal situation is if the spring member realises a snap action on the terminal fingers so that they are held immobile in relation to one another.

The connector housing is preferably designed so that two identical parts can be connected together to each other, i.e. the design is such that the housing is reversible. This is an advantage in manufacture, since only one tool is needed. Moreover, storing, assembly and operation of the connector devices are facilitated, since it is not necessary to take into account the use of different variations of the connector device. Thus, male and female contacts are not necessary, but the connector devices are occasionally referred to as 'hermaphrodites'.

The terminal fingers are of a design which in principle has been adopted as an informal standard in the trade. Their rear end has an elongate sleeve for receiving a stripped cable end. When the cable end has been inserted, the sleeve is crimped, clenched or otherwise deformed so that the terminal fmger is reliably connected on the cable. The front end of the terminal finger is substantially planar with a transverse rounded ridge or tip at its front edge. The front flank of the ridge is of such a design that a similar terminal finger can quite simply slide over the ridge for a permanent connection between the terminal fingers when they are each mounted in their connector device. The material of the terminal fingers is preferably a good conductor, normally silver plated copper, while other materials could per se be possible.

The metal spring that is provided for realising requisite contact pressure between the terminal fingers and positioning them in the connector housing is preferably manufactured from a stainless material, with suitable, resilient properties.

One example of a connector device according to the prior art technology is disclosed in USPS 4,335,931, in which is shown a connector device with a metal spring having a tongue which is depressible on release of the terminal fingers. Further, the connector housing is provided with a recess for retaining the metal spring, as well as a latch covering this recess.

Manufacturing the spring from metal has hitherto been the only method of incorporating the spring with sufficient contact force in the connector housing. However, there are a large number of disadvantages inherent in metal springs of the prior art type. These disadvantages relate substantially to the manufacture and mounting of the spring. One problem is that accuracy is poor in both the material properties and in the punching operation of the metal spring. Granted, it is possible to obtain improved material properties at a higher raw material price, but this has a negative effect on the price of the finished connector device. One consequence will be that certain connector devices function less satisfactorily, or at worst do not function at all, since the low degree of accuracy has resulted in the force of the spring being overly great or insufficient for satisfactory operation. The poorly functioning connector devices are generally discovered in quality inspections and are rejected in such instances, but rejects entail increased costs.

A further problem is that the mounting of the metal spring in the connector housing is rather complicated. USPS 4,335,931 discloses a solution where the connector housing is provided with a loose latch in order to make for retention of the metal spring. Another solution is that the metal spring is first laid in position whereafter the connector housing is deformed in one or more points, preferably by melting of the plastic in the connector housing, in order to render removal of the spring impossible. It is difficult to achieve a high level of precision in these working phases, in particular in the case when the plastic is melted, and quality runs the risk of suffering.

Regardless of the methods employed for mounting and retaining the metal spring in the connector housing, the mounting operation entails an extra working phase which must either be carried out manually or which requires special equipment or special machines. Moreover, a design and construction with a loose spring entails that more parts must be manufactured and kept in store, which per se involves an extra cost.

The negative relationship between cost and quality results, in the worst case scenario, that systems are designed where connector devices are avoided; on the one hand to reduce costs and on the other hand to eliminate potential problem sources. The drawback in such a solution is that the convenience and flexibility which are offered by a system involving connector devices is not utilised.

PROBLEM STRUCTURE

The intention is thus to realise a connector device whose manufacture is both simple and rapid, and as a result economical, at the same time as the quality of the connector device is improved or at least maintained. SOLUTION

The object forming the basis of the present invention will be attained if the connector device intimated by way of introduction is characterised in that the spring member is of one piece manufacture with the connector housing.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will now be described in greater detail hereinbelow, with reference to the accompanying Drawings. In the accompanying Drawings:

Fig. 1 is a straight side elevation of a connector device according to the present invention;

Fig. 2 is a straight side elevation of two similar interconnected connector devices according to Fig. 1 ;

Fig. 3 is a sectional view of the interconnected connector devices according to Fig. 2;

Fig. 4 is a view in the direction of the arrow A in Fig. 1;

Fig. 5 is a view corresponding to that of Fig. 3 of an alternative embodiment of the present invention; and

Fig. 6 is a view corresponding to that of Fig. 4 of the alternative embodiment as shown in Fig. 5.

DESCRIPTION OF PREFERRED EMBODIMENT

Fig. 1 shows a connector device 1 according to the present invention. The connector device 1 appears seen from the outside as quite conventional, in that it comprises a connector housing 2 which complies with the conventions existing in the trade, so as to be usable together with existing connector devices. The housing has undercut interconnecting devices 2, 3 for interconnecting two or more connector devices 1 side-by-side or above one another. The interconnection takes place in such a manner that neither the terminal fingers in the cables in the connector device have any electric communication with each other. This makes for an electric connection of a large number of cables at the same time, in a simple and reliable manner. Like many other similar connector devices, the connector device 1 is reversible. The purpose of this is to make for an electric connection of two connector devices which are manufactured with the aid of the same tool. For this reversibility, the front end of the connector housing 2 is designed so that an outer casing 5 surrounds the connector device 1 halfway, while an inner wall 6 is disposed in such a manner that the outer casing 5 of a corresponding connector device 1 is disposable about the inner wall 6. The connector housing 2 is open at its outer ends 7 and 8, seen in the longitudinal direction, in order to make possible the insertion of terminal fingers in the front end 7 as well as the connection of a cable in the rear end 8.

Fig. 2 shows two connector devices 1 which are connected to each other for an electric connection. For the sake of simplicity, the cables joined to the connector devices 1 have been omitted from the Drawing. In the Figure, it is clearly visible how the outer casings 5 on each connector device 1 complement each other and create a protective casing. For this purpose to be possible, it is important to ensure accurate manufacture and a good fit between the two parts.

Fig. 3 shows in cross section the two interconnected connector devices 1 according to Fig. 2. In this instance, the terminal fingers 9 are shown which are connected each to the end of a cable (not shown). The front ends of the terminal fingers 9 are acted on by a force from their respective spring member 10. Each one of the spring members 10 is of one piece manufacture with the connector housing 2 and extends forwards towards the front end 7 of the connector device 1 inside its inner wall 6.

An inner partition 11 is disposed transversely of the longitudinal direction of the connector device 1 so that a narrow channel 12 is created through which only the front end of the terminal fmger 9 is passable. Thus, the partition 11 constitutes a support which prevents the terminal fmger 9 from moving forwards in the connector housing 2. The upper edge of the partition 11 also constitutes a pivot point for the terminal finger 9 when this is pressed downwards by its associated spring member 10. At the same time, the terminal fingers 9 are permitted to pass one another on bringing together two connector devices 1, since the spring member 10 is then pressed back when the ridges of the terminal fingers 9 pass one another. Ahead of the spring member 10, i.e. at the front end 7 of the connector housing 2, there is disposed a front wall 13. The front wall contributes to the stability of the connector housing 2 and may possibly, to some degree, function as a tamper-proof safety device. The front end 13 extends however no further than that an interconnection of two connector devices 1 is possible. It should further be observed that, when the spring member 10 is completely unbiased, the front wall 13 and the spring member 10 are of substantially the same extent transversely of the longitudinal direction of the connector housing 2, principally for production engineering reasons.

The terminal fingers 9 are, as was described by way of introduction, of a quite conventional configuration, in order to match with the terminal fingers already existing on the market, as well as for making possible use of the connector device 1 according to the present invention together with older components. In this instance, the cupped, ridge-like shape at the front end of the terminal finger 9, as well as the notch 14 on the opposing side of the front end of the terminal fmger 9 are of particular importance. In the prior art technology, the notch 14 has been employed as an abutment for the metal spring described by way of introduction.

The spring member 10 is of a configuration which, in its front end, is complementary to the front end of the terminal finger 9, i.e. the spring member 10 has a projection 15 which grips in the notch 14. The shape of the spring member 10 with the projection 15 thus prevents, by its engagement with the notch 14, the terminal finger 9 from moving backwards on connection of two connector devices 1 to each other. Correspondingly, the partition 11 prevents the terminal finger 9 from being disturbed when two connector devices 1 are pulled apart. The distance between the notch 14 of the terminal finger 9 and its securing sleeve corresponds with great accuracy to the distance between the projection 15 and the partition 11 so that play between the mounted terminal finger 9 and the connector housing 2 is eliminated. As a result, play is also eliminated between two terminal fingers 9 which are electrically connected to one another.

The spring member 10 is narrowest at its rear end, i.e. that end which is most proximal the connector housing 2, which entails that the greatest stress will be obtained in this region and maximum flexing at the front end of the spring member 10. This flexing, like the springing from the metal spring according to the prior art technology, is necessary for interconnecting and separating two connector devices 1 since there will hereby be obtained a snap function.

Fig. 4 shows the connector device seen in the direction of the arrow A in Fig. 1. It will be apparent from Fig. 4 that the spring member 10 in the preferred embodiment is, on the one hand, visible from this angle and, on the other hand, is surrounded by a slot on three sides. This design permits relatively simple manufacture and tool design. Granted, the slot 16 entails that the connector device 1 appears to be more exposed to, for example, moisture, but it should be observed that the spring member 10 will be covered by the outer casing 5 on a corresponding connector device 1 when two connector devices 1 are connected to each other.

The entire connector device 1, with the exception of the terminal fingers 9, is thus of one piece manufacture, preferably from a plastic material and preferably by injection moulding. This implies that manufacture may be put into effect with extremely high precision, in particular regarding dimensional and flexural properties. Since use is no longer made of several components which are assembled to form a unit, the manufacturing tolerances will be somewhat less critical, since they are not cumulative in effect as in the assembly of several parts. Quality will be kept at a high and uniform level. The individual plastic parts will be mutually alike with great dependability, which implies that parts are easily replaceable on repair and retro-designing of systems, without specific adjustments. A further advantage is that no retrofitting or retroprocessing apart from the insertion of the terminal fingers 9 is required. Difficult working phases such as the melting of plastic to keep a loose spring in place are obviated and the quality of the finished connector device will be improved. As a result, reject frequency will also be reduced.

The improved quality and lower cost probably entail that the connector device is usable in even more applications than previously, where use had been made of fixed installations instead of connector devices.

DESCRIPTION OF ALTERNATIVE EMBODIMENTS

In a view corresponding to that of Fig. 3, Fig. 5 shows an alternative embodiment of the present invention. According to this embodiment, a surrounding wall 17 is provided on the outside of the spring so that the slot 16 is no longer visible from outside. For reasons of production engineering, the front wall 13 has been omitted in this embodiment, to make for simplified manufacture. The connector device 1 according to this embodiment has apertures only at its front end 7 and rear end 8, respectively.

In a view corresponding to that of Fig. 4, Fig. 6 is a view in the direction of the arrow A in Fig. 1. The surrounding wall 17 entails that the connector device 1 appears as better encapsulated, and moreover the risk of damage to the spring member 10 by external action is minimised since it is more inaccessible.

In the above description and on the Drawings, a connector device has been disclosed as having a single terminal finger 9. It is worth pointing out that it is conceivable to manufacture the connector device 1 according to the present invention in which several terminal fingers 9 are disposed in side-by-side relationship in the same connector device 1. Preferably, one spring member 10 is allocated to each one of the terminal fingers 9, even through variations are conceivable in which the spring member 10 has been made wider and acts on more than one terminal finger at the same time.

The present invention may be further modified without departing from the scope of the appended Claims.

Claims

WHAT IS CLAIMED IS:

1. A connector device comprising a connector housing (2) in which is disposed at least one terminal finger (9) and a spring member (10) associated with the terminal finger (9) for realising requisite contact pressure between two terminal fingers (9) on interconnection of two connector devices (1), characterised in that the spring member (10) is of one piece manufactured with the connector housing (2).

2. A connector device comprising a connector housing (2) in which is disposed at least one terminal finger (9) and a spring member (10) associated with the terminal finger (9) for realising a positioning and fixing of the terminal finger (9) in the axial direction of the connector housing (2), characterised in that the spring member is of one piece manufacture with the connector housing (2).

3. The connector device (1) as claimed in Claim 2, characterised in that the spring member (10) further realises a snap fixing of the terminal fingers (9) on interconnection of two connector devices (1).

4. The connector device (1) as claimed in any of Claims 1 to 3, characterised in that both the connector housing (2) and the spring member (10) are manufactured from plastic.

5. The connector device (1) as claimed in any of Claims 1 to 4, characterised in that the spring member (10) extends in the longitudinal direction of the connector housing (2) as an extension of its outer wall.

6. The connector device (1) as claimed in any of Claims 1 to 5, characterised in that the spring member (10) is disposed inside a surrounding outer wall (17) of the connector housing (2).

7. The connector device (1) as claimed in Claim 5 or 6, characterised in that the spring member (10) is partly surrounded by a slot (16) along several of its edges.