WO1982000924A1

WO1982000924A1 - Connection device for connecting low-voltage lines of vehicles

Info

Publication number: WO1982000924A1
Application number: PCT/SE1981/000240
Authority: WO
Inventors: M Kullberg
Original assignee: M Kullberg
Priority date: 1980-09-02
Filing date: 1981-08-27
Publication date: 1982-03-18
Also published as: EP0058704A1; SE8006105L; SE431808B

Abstract

A connection device for use as a trailer connector for vehicles, comprising two identically shaped connection members with contact elements (1). The contact faces of the contact elements are plane and exposed. When coupling together the connection members, the corresponding contact faces are pressed against one another by coupling guides (3) with sliding faces (31) arranged at an angle. In the coupled state the connection members can be secured by means of a locking element (13) which also acts as a locking element for a cover protecting the contact faces when the connection member is uncoupled. Inasmuch as the contact elements do not comprise any pans inserted into one another it is easy to inspect and clean the contact faces.

Description

Connection device for connecting low-voltage lines of vehicles.

The present invention relates to a connection device for connecting low-voltage lines of vehicles comprising two connection members suitable for coupling with one another and of identical design, each of the said members having one or several electrical contact elements, whereby corresponding contact elements in respective contact members make contact with one another when the connection members are coupled together, means being provided for securing the connection members in the coupled condition.

Connection devices of the type described above are already known and described in the vernacular as "trailer connectors" since they are normally used for connecting or coupling electrical lines in a towing vehicle with corresponding lines in a trailer or caravan. With a conventional trailer connector one connection member is designed as a socket with four sleeve-shaped female contact elements and three stud- or pin-shaped male contact elements, the second connection member being designed as a plug matching the socket, with four pins and three sleeves. The pins are split lengthwise into four sections. The sections exert pressure on the inner walls of the sleeves, as a result of which the plug is retained in the socket. A common problem with a trailer connector of this type consists in breaks of contact owing to the fact that the pins and/or sleeves are coated with oxide or some other impurity or that the contact pressure between them has diminished owing to a relaxation of the pin section resilience or widening of the sleeve. Hot only is it difficult with a connection device of such design to trace any contact fault since in the first place the sleeves are almost inaccessible for direct inspection but the cleaning of the contact sleeves and also the pin sections presents major problems. As a result, faults of this type often make it necessary to replace a trailer connector in its entirety, which entails costs. Another consequence may consist in reduced traffic safety since trailers and caravans with such connection devices are driven without adequate lighting.

The SE patent applications 7708181-8 and 7016571-7 published for opposition describe connection devices of the type in question. Each of these devices comprises two identically designed connection members with co-operating contact elements of plug-in type inasmuch as parts of the contact elements are inserted into one another when, they are coupled together. In view of the contact element design these connection devices are accordingly directly comparable with the known devices described above and subject to the same deficiencies as regards the possibilities for direct inspection and cleaning of the contact elements.

It is the object of the present invention to produce a connection device suitable for use as a trailer connector, in which the deficiencies of the known devices are eliminated and where the contact elements are accessible for direct inspection and can easily be cleaned.

The object of the invention is achieved by means of a connection device of the type initially mentioned which according to the invention is characterised in that the effective contact face of each contact element is plane and exposed within a contact plane at the level of abutment between the connection members, and in that each connection member is provided with a sliding face en a coupling guide or corresponding device for coupling the connection members, the said sliding face being at an angle in respect of the contact plane, whereby the sliding faces of the connection members slide along one another when the said connection members are being coupled together and the contact faces of the contact elements are pressed against one another in the course of the sliding movement until a defined state of coupling has been reached.

The proposed design of connection device contact organs with exposed contact faces, which are only pressed against one another without being inserted into one another enables simple inspection and cleaning. The sliding faces of the connection members and the ensuant sliding movement which takes place between the contact faces of the contact elements during coupling entails an advantageously self-cleaning effect on the contact faces. The fact that the connection members are of identical designs yields advantages in respect of manufacture, storage and sale. With a preferred embodiment of the connection device in accordance with the invention each connection member is fitted with a hinged protective cover, which in its closed position protects the contact faces of the contact elements when the connection members are separated, whereby the protective cover is characterised by a locking element which, on the one hand, can be made to engage a first recess in the connection member thus maintaining the cover in the closed position, while, on the other hand, it can be made to engage, in the open position of the cover, another recess in the second connection member thus serving as the aforementioned means for securing the connection members in the coupled state.

In the following an embodiment is described of the connection members forming part of the connection device in accordance with the invention, reference being made to the attached drawings, in which fig. 1 shows a frontal view of a connection member in accordance with the invention and with the protective cover in the open position, which illustrates the contact plane of the connecτion member, fig. 2 shows a view from below of the connection member in fig. 1 with the protective cover in the closed position, fig. 3 shows a side view of the con nection member in fig. 1 and fig. _4 shows the side view of fig. 3 after rotation by 180° .

The connection member in fig. 1 comprises seven conτact elements 1 with rectangular, plane contact faces constituting a contact plane. It will be apparent that the number of contact elements is entirely optional. The contact faces are designed so as to project to some extent from the body 7 of the connection member and are maintained in this position by appropriate helical compression springs 5 (see fig. 2) With each contact element there is a space 6 into which that part of the contact element which supports the contact face can be inserted. A protective cover 4 which can be opened and closed by means of a pin 8 and, in the closed position, covers and protects the contact faces of the contact elements is shown in the open position. The sides of the connection member are provided with two coupling guides 3 for coupling the connection member with another, identically designed connection member. The detailed design of the coupling guides will be seen in figs. 2 and 3.

Fig. 2 shows the connection member of fig. 1 in a view from below, with the protective cover 4 in the closed position. Fig. 2 includes a section along the line I-I in fig. 1 , showing the detailed design of the contact elements and matching parts of body 7 of the connection member. The contact element 1 is made of a contact metal of the same type as used in known connecτion devices and is, with the present embodiment, U-shaped, which is shown diagrammatically in figs. 3,4. Every contact element has two legs 9. which at one end pass into the part supporting the contact face and at the other end into a connection pin 10.

The partial section in fig. 2 shows one of the legs 9 of three of the seven contact elements present. Each leg 9 is longitudinally displaceable within a corresponding duct 11 in body 7 against the force exerted by a corresponding helical compression spring 5. The helical spring 5 is fitted over leg 9 and accommodated within an enlarged section of duct 11. The upper end of helical spring 5 abuts a stop 12 on the leg. By means of an upper shoulder in duct 11 stop 12 also defines the position of the contact face when the connection member is uncoupled. The other end of the helical spring abuts a lower shoulder in duct 11, as a result of which the leg is pressed upward by the helical spring. The contact elements provided with helical springs in the said manner exerts a well defined contact pressure between the contact faces of two coupled connection members, the time during which the device has been in use being substantially immaterial.

Protective cover 4 is provided with a space 2 for the somewhat projecting contact faces of the contact elements, so that the helical springs are not stressed by the cover in its locked position.

It can be seen from the above that the connection terminals 10 of legs 9 are somewhat displaced when two connection members are coupled together. When the connection member, for instance during use as part of a trailer connector, constitutes a termination of a number of lines this displacement does not give rise to any problem. If fixed connection terminals or pins are required, this can be easily achieved by making the helical spring 5 conductive and removing that part of leg 9 which is located between stop 12 and the lower end of the helical spring (see fig. 2). The remaining terminal section 10 of the leg is fixed in body 7 and connected to the helical spring, for instance by means of an element similar to stop 12. Via stop 12 the spring is in contact with the upper part of leg 3. As a result a closed circuit is achieved between connection terminal 11 and the contact face of the contact element.

The side view in fig. 3 shows the design of coupling guides 3. The guides 3 are firmly secured to body 7 of the connection member, each of them possessing a sliding face 31 which is at an angle in respect to the contact plane of the connection member. The sliding face 31 is plane so that it can easily slide along the corresponding sliding face of the other connection member when the two are coupled together. Cover 4 is provided with a locking element 13 in the manner of a snap locking device. Locking element 13 has the dual function of locking the cover in the closed position by engaging a first recess 14 and, on the other hand, securing the connection member in the couple state by engaging a second recess 15 in the other connection member (see 15', fig. 4). This design of the cover and its locking element thus makes it unnecessary to provide special means for securing the connection members.

The side view in fig. 4 corresponds with the view in fig. 3 but it has been rotated by 180° in order to illustrate the coupling together of two connection members. The reference numbers in fig. 4 correspond with those in fig. 3 nut have been provided, for clarity's sake, with prime symbols.

When coupling together two connection members the initial position of the connection members is that shown in figs. 3 and 4 after openingthe respective protective covers 4,4' having released the locking elements 13,13' from recesses 14,14'. From this position the connection members are moved towards one another as indicated by the two arrows 16. The sliding faces 3 and 3' of the coupling guides begin to slide towards one another and the contact faces of the contact elements 1 and 1 ' are approached above one another. As the connection members are approached further, the contact faces are pressed against one another in a sliding movement, and the contact elements are displaced in the respective connection member bodies against the spring forces exerted by the corresponding helical springs 5 (see fig. 2). When the contact faces are central in respect of one another the process of coupling the connection members is discontinued. With the embodiment shown this position is defined in that the side sections of one connection member abut the open cover of the other member and viceversa. The position can also be defined in another manner, for instance by means of a projection on coupling guides 3 or 3 ', which prevents the connection members from being brought further together, or by causing the front faces of the connection members to abut.

In this position the connection members are secured to one another by introducing the locking elements 13 and 13 ' into the respective recesses 15' and 15. It will be apparent that in a modified embodiment the parts of the connection members' contact faces which at the coupling stage are brought into contact first may be chamfered or rounded so as to facilitate bringing together of the connection members to the greatest possible extent.

Claims

1. A connection device for connecting low-voltage lines of vehicles comprising two connection members capable of being coupled with one another and of identical design, each of the said connection members having one or several electrical contact elements (1), whereby the corresponding contact elements in the respective connecτion member are brought into contact with one another when the connection members are coupled together, means being provided for securing the connection members in the coupled state, c h ar a c t e r i s e d in that the effective contact face of every contact element (1) is plane and exposed in a contact plane at the abutment level between the connection members, and in that each connection member possesses a sliding face (31) on a coupling guide (3) or corresponding device for coupling together τhe connection members, the said sliding face being at an angle in respect of the contact plane, whereby the sliding faces of the connection members slide along one another during the coupling process and the contact faces of the contact elements (l) are pressed against one another with a sliding movement until a defined state of coupling has been achieved.

2. A connection device in accordance with claim 1 in which the contact faces of the contact elements (1) are designed so as to yield and project slightly in respect to a surface of the connection member, c har a c t e r i s e d in that each contact element (1) comprises at least one helical spring (5) arranged to keep the contact element resiliently prestrεssed towards the aforementioned projecting position.

3. A connection device in accordance with claim 2, c h a r a c t e r i s e d in that the contact element (l) is U-shaped and has two legs (9) which at one end pass into the part of the contact element supporting the contact face and at the other end pass into connection terminals (10) for the lines, and in that each leg passes through a helical spring (5) which by abutment against a stop (12) on the leg and a stop in body (7) of the connection member brings about the aforementioned πrestress.

4. A connection device in accordance with any of the above claims, whereby each connection member is provided with a hinged protective cover (4), which in its closed position protects the contact faces, of the contact elements when the connection member is uncoupled, c har a c t e r i s e d in that the protective cover (4) is provided with a locking element (13) as well as a first and second locking recess (14,15 and 14', 15', respectively), whereby engagement of the locking element with the first recess (14) causes the protective cover to be maintained in the closed position and whereby engagement of the locking element with the other recess (15') of the second connection member maintains the connecxxon members in the coupled, state.

5. A connection device in accordance with claim 4, c h ar a c t e r i s e d in that the protective cover (4) is provided with a space (2) which when the protective cover is closed accommodates the projecting parts of the contact elements (1).