The invention relates to the structure of an electrical connector and to the assembly and also fabrication of it. The object of the invention is an electrical installation terminal block according to claim 1, a method according to claim 8 for fabricating the electrical installation terminal block, and the use according to claim 9 of the electrical installation terminal block.

The aim of the invention is to provide a multipolar electrical installation terminal block that can be used also at large currents and high voltages, e.g., as part of a system for charging electric vehicles. The operational quality of the electrical installation terminal block according to the invention is improved in terms of safety compared to a connector according to prior art.

Prior art is represented by at least publications DE 4231244 Al, EP 3029776, and DE102011050212, and FI 20175848.

Closest to prior art is the aforementioned publication FI 20175848, the present patent application being based on the connector disclosed therein. The publication discloses an electrical connector to which a part improving electrical safety has now been added according to the present invention, in which case the properties of the electric connector are substantially improved.

The electrical installation terminal block according to publication FI 20175848 is used for the electrification of parking areas in such a way that the cabling of the parking area is first connected into a chain by means of the connector so that the incoming cable is connected to the connector and the outgoing cable is connected to the next connector. Since many connectors are installed in one installation and there can be many connectors in the chain, it is important that the installation work is as easy and quick as possible. Furthermore, it is advantageous if one or more cables of different thicknesses can be easily connected. The connector is easy to assemble because only two parts for one connector contact are needed for the connector body itself, which parts are easy to push into place, after which they are held in place by friction. Once the connector body with the contacts is assembled, it can be slid into the bottom of the device enclosure along rails, or the connector body can be attached in some other way to the device enclosure. The connector body can then be locked in place either with a separate means, such as with a pin, a screw, or a flexible latch. The connector body may also remain in place held only by the cover of the enclosure if suitable holes have been formed in the cover, into which holes the mating parts of the connector body fit. The live parts of the connector body are sufficiently shielded when it is installed into position. The connector body can be installed in the quick-connector enclosure, e.g. on the end of an engine-block heater pole in a parking area, on the wall of a parking garage, or on a mounting rail, and later e.g. a car heating unit that has time switches can be installed in the connector.

The connector body itself usually remains inside the device enclosure. In this case, the device enclosure may be e.g. an enclosure that is attached to the end of an engine-block heater pole of a parking space, and can be openable from one or two sides. When the cable conductors have been installed in the connector body, the connector body needs to be attached to the device enclosure. This may be performed e.g. by sliding the device enclosure horizontally, in which case the front panel of the device enclosure is openable, through which also the cable ends are installed. It is also possible to slide or attach the device enclosure from below, in which case the enclosure installed on the pole will be slid along the pole from below. In this case, one part of the enclosure has been threaded onto the pole before installation of the conductors and will be lifted into its position after the installation.

The device enclosure may have a cap, which is removable for connecting a male connector. The cap protects the contact surfaces of the connector from human contact with conductive objects, and from impact, touching and the weather before the connection of the male connector. The device enclosure may have a sturdy metal face provided with connecting means for attaching the male connector of e.g. an engine-block heater device or a device for charging an electric vehicle. This allows easy changing of hardware in a parking area.

The cables themselves may be attached in such a way that the peeled ends of the cable are first pushed into the space between the insulation walls, and after that a screw clamp connector is pushed onto the end of the cable and around the end of the contact strip, and the screw is tightened, causing the ends of the cable or cables to be squeezed against the contact strip. The screw clamp connector itself is reminiscent of a pillar terminal, differing in that in this solution the screw clamp may be manufactured out of square tube, and the cable and contact strip to be installed in it will be parallel in the finished connection. In addition, the screw clamp connector may have a means that distributes pressure and acts as a spring either between the screw and the cable or between the back of the cable and contact strip and the base of the screw clamp connector. It is known that a spring is needed at least when aluminum cable is used outdoors, in which case the larger coefficient of thermal expansion of aluminum compared to copper alloys or steel causes deformations of the cable and finally loosening of the joint unless a flexible means is used. A connector may also be built using pillar terminals, in which case the space requirement of the wiring may increase, however, in the height direction in order to meet the requirements for insulation and installation space. Naturally, the cables may be attached using another known method, e.g., with sleeve connectors or screws.

The purpose of the invention is improve the electrical safety of the type of electrical installation terminal block presented above by keeping the electrical connection functional also in extreme conditions when the connector body of the electrical installation terminal block is destroyed.

The above is achieved by adding sleeves that are essentially square in cross-sectional shape into the connector body of the electrical installation terminal block.

According to the invention, sleeves that are essentially rectangular in cross-sectional shape are installed as an insert into the connector body in the casting phase of the connector body, which sleeves improve the electrical safety of the electrical installation terminal block. The aforementioned sleeves hold the contact strips of the male connectors in contact with the female connectors and the connections are electrically safe, even if the connector body were to melt around the connections.

The invention is characterized by what is disclosed in the characterization portions of independent claims 1, 8 and 9, and the dependent claims disclose the various embodiments of the invention.

In the following, the invention will be described in more detail by referring to the drawings, wherein

Fig. 1 presents a cross-section of an electrical installation terminal block according to prior art, before assembly,

Fig. 2 presents the parts of the cross-section of Fig. 1 when assembled,

Fig. 3 presents a solution according to prior art of an assembled body of an electrical installation terminal block with screw clamps

Fig. 4 presents a sleeve of rectangular cross-sectional shape according to the invention, and

Fig. 5 presents a cross-sectional view of one rectangular sleeve according to the invention installed as an insert into the connector body of the electrical installation terminal block.

Fig. 1 depicts the connector body 1 and the parts of an electrical installation terminal block according to prior art, before assembly. Differing from what is drawn in the figure, the screw clamp 6 in Fig. 1 can be unattached before installation of the cables, in which case the cables are easier to install into position, and the connector is inserted only when the cables are in place.

The contact strip 3 is a flat plate-like part bent into a U-shape. It is preferably bent in such a way that the angles differ somewhat from a right angle, causing the contact strip to attach to the connector body with a small compressive force. In terms of manufacturing technology, this is also easy to implement, since a strip bent to an angle of 90 degrees usually reverts into a slightly more obtuse angle by itself after the bending. The contact end 3.1 of the female connector of the contact strip may be beveled according to the figure in order to guide the strip of the male connector. The end 3.2 is attached to the cable, e.g, with the screw clamp connector 6. The spring 4 presses the strip of the male connector tightly against the contact 3.1 of the female connector. The spring also functions to some extent as a body that conveys electrical current. Both the contact strip 3 and the spring 4 are installed into the connector body 1 via the aperture 2. It should be noted that in Fig. 2 the spring 4 is drawn in a tensionless state, differing from reality, causing it to appear to pass inside the connector body. In reality, the spring is naturally compressed against the contact strip, and does not go inside the connector body.

The connector body 1 is made up of suitable insulating material that withstands the required mechanical and other stress. Between each point of connection is a wall 5 made of insulating material, the walls separating the connectors from each other. The contact strips may be made of e.g. nickel-plated and silver-plated copper, and the spring may be made of e.g. bronze or steel. The strips need to be dimensionally precise and flat so that the contact surface is sufficiently large. In practice, it is sufficient that the strip is made flat enough at least with regards to the contact area before bending the strip into a U-shape, or the strips are pressed, ground or machined to be flat enough after the bending or before it. The bending somewhat changes the cross-sectional shape of the contact strip, at least close to the location of the bending, but it does not usually matter if the angle to be bent is located relatively far from the contact area itself.

Fig. 2 depicts a connector body according to prior art, when assembled. Differing from the figure, the screw clamp connector 6 is usually unattached before installation of the cable. In addition, the screw clamp is described in the figure with the screw screwed in. Naturally, the screw is unscrewed during the installation so that the screw clamp can be threaded into place around the cable and the end 3.2 of the contact strip. An unattached or detachable screw clamp connector makes cable installation easier. The cable pair may be cut or bent to the right length for the connector, after which the cable pairs are marked for the correct peeling length. The cable pair is peeled and the screw clamp connector 6 is threaded onto the cable pair and contact strip 3.2. The screw clamp is pretightened after its final positioning. The cable pair is cut with wire cutters to the correct length as close to the connector as possible, after which the screw clamp is tightened to torque. This avoids threading a rigid cable into the connector. According to tests, the savings in work time are significant; in addition, it is easy to install two cables into the same connector to chain the cables. The insulation walls 5 of the connector body contribute to holding the cables to be installed in place during installation. The insulation walls make installation easier and create a sufficient insulation gap. The screw clamp 6 may have a flexible part so that e.g. the forces produced by the thermal expansion of the cables and the connector remain so small that no permanent deformations or loosening of the cable connection occur. The spring 4 and the first end 3.1 of the U-shaped contact strip form a contact area for the male connector to be received.

Fig. 3 depicts an example of a 5-pole connector body 1 according to prior art, when assembled but without cables. The contact strips of the male connector protrude from the apertures 10 to the contact. Around the apertures 10 there is an enclosure that remains inside the protective casing of the male connector when the connectors are attached to one another. The apertures 10 may come out from the cover of the device enclosure in such a way that on the cover of the enclosure is a sufficient gap for the casing of the male connector. In this context, the terms male connector and female connector describe mostly that the female connector is fixed, and the electrical current is supplied from the female connector described here into the male connector. There is no distinctive difference in the structure of the connectors themselves between the male and female connector.

It is easiest to press the cables into the space between the insulation walls 5 with a suitable tool or even with a finger and after that thread the screw clamp into place in the position according to the figure. As the installation cables are quite rigid and thick, it is considerably easier to cut and peel the cables to their correct length and push them sideways into place and only after that thread the screw clamp connector into position. Thus, the cable is pushed sideways onto the ends 3.2 of the contact strips and the screw clamp connector is threaded around the cable and the end of the contact strip from the above direction of the figure and the screws are tightened in such a way that the cables are pressed against the contact strips. In this way, there is no need to bend the cable sharply for the threading, but it is enough that it is pushed into place and the screw clamp is threaded around the cable. After installation of the contact strips, the connector body itself can be pushed by means of the rails 9 into attachment with the body of the device enclosure.

Fig. 4 depicts a sleeve 20, according to the invention, of essentially rectangular cross- sectional shape. The sleeve 20 is used as an additional structure e.g. in the solution according to prior art presented in Figs. 1-3. These types of sleeves 20 are placed around all the connections to be formed in the body of the connector. For example, there are 5 of them in the 5-pole connector body 1 according to Fig. 3. The shape of the sleeve 20 does not need to be an absolute rectangular piece, but instead the angles of the sleeve can be slightly rounded.

Fig. 5 shows the connector body 1 of the electrical installation terminal block presented in Fig. 2 and the sleeve 20 of essentially rectangular shape connected to it according to the invention as an insert during the casting. The sleeve 20 is situated around the electrical contact to be formed, and its task is to keep the electrical connection intact even if e.g. the connector body 1 were to otherwise be destroyed e.g. by melting or mechanically. The electrical connection has been formed by means of the first end 3.1 of the U-shaped contact strip 3, the spring 4 and the contact strip of the male connector (not presented in the figure). When making the connection, the contact strip of the male connector protrudes into the gap 30 formed by the first end 3.1 of the U-shaped contact strip 3 and the spring 4. Since the sleeve 20 tightly around the connection keeps the connection intact, the electrical safety of the device is substantially improved compared to prior-art solutions. Sleeves 20 are installed in the connector body 1 around each electrical connection, in which case the whole connector body 1 is rendered electrically safe. Sleeves 20 are installed in the connector body 1 at different distances from the apertures 10 of the connector body to correspond to the position of the electrical connections to be formed in the connector body. The position of an electrical connection is determined by the length of the spring 4, whereby the electrical connection of a longer spring is connected first and the electrical connection of the shortest spring is connected last. Similarly, the length of the first end 3.1 of the contact strip 3 is also dimensioned in such a way that the length of the first end 3.1 corresponds to the length of the spring 4 and the position of the electrical connection in the connector body 1. The connector body is designed in such a way that, for example, the different phases of a 5-pole electrical connector as shown in Fig. 3 are connected and opened in a certain electrically safe sequence when the connector is being connected or opened. This is implemented in such a way that the electrical connections formed are at different distances in the connector body 1 from the apertures 10 of the connector body, into which apertures the contact strips of the male connectors protrude, in which case when the male connector is pressed into contact with the female connector, the correct connection and opening sequence is automatically obtained. In the electrical connection depicted in Fig. 5, the sleeve 20 is installed closest at its uppermost point to the aperture 10, and the spring 4 is longest in dimension extending closest to the aperture 10. Thus, the first electrical connection forms when the male connector is connected to the connector body 1. The connection sequence of the other electrical connections of the connector body is selected by changing the position of the sleeve to be farther from the aperture 10 and by changing the length of the spring 4 correspondingly. The length of the first end 3.1 of the contact strip 3 is dimensioned in such a way that the length of the first end 3.1 corresponds to the length of the spring 4 and the position of the electrical connection in the connector body 1, in which case the connection sequence can be implemented.

In other respects, the connector body 1 according to the invention corresponds to the priorart connector body presented in Figs. 1-3.

The method according to the invention for fabricating an electrical connector comprises the following phases: a casting mold is prepared for the connector body 1 of the electrical connector,

- the essentially rectangular sleeves 20 are placed in the casting mold, the number of which sleeves corresponds to the number of electrical connections of the connector body 1,

- the distance of the sleeves 20 from the apertures 10 of the connector body 1 to be formed is determined in such a way that the gaps 30 surrounded by the sleeves 20 form the pairs formed by the first ends 3.1 of the U-shaped contact strips 3 and the springs 4, when the parts 3 and 4 have been installed in the connector body 1,

- the casting is performed,

- the U-shaped contact strips 3 and springs 4 of different lengths are installed in the connector body, the length of the first ends 3.1 of the contact strips 3 corresponding to the length of the springs 4 of different lengths and the means for connecting cables to the connector body 1, a gap 30 is formed with the first ends 3.1 of the U-shaped contact strips 3 and the springs 4, which gap receives the contact strip of the male connector.

The invention further relates to the use of an electrical connector according to the invention for installing the chargers or engine-block heaters of electric vehicles.

It is obvious to the person skilled in the art that the invention is not limited solely to the examples described above, but that it may be varied within the scope of the claims presented below. Thus, for example, some phases of the method can be in a different sequence than what is presented above and, in addition, some phases of the method can be absent and some phases of the method not presented can be included. Furthermore, some phases of the method can include more or fewer functions than what is presented above.