The invention relates to a contact element for connecting an electrical conductor.
For joining connecting wires to a printed circuit board, for example, at the conductors the connecting wires are soldered or connected to the printed circuit board by means of printed circuit board clips. Printed circuit board clips based on a screw, spring, or insulation displacement clip are known. The contact elements for the spring clips are generally composed of a correspondingly bent metallic band such as a cage tension spring, for example.
Printed circuit board clips having screw clamping are often cumbersome to operate. The contact elements for the spring clips are sometimes difficult to manufacture due to the variations in the bending process, which require a comparatively large quantity of metallic material.
The object of the invention, therefore, is to provide a contact element which is easily and economically manufactured and which allows an electrical conductor to be easily connected.
The object of the invention is achieved by a contact element having the features of claim 1. The object of the invention is further achieved by a method for connecting an electrical conductor, having the features of claim 11.
Advantageous embodiments and refinements of the invention are stated in the subclaims.
The contact element according to the invention for connecting an electrical conductor has a flat electrically conductive base element in which at least one passage is provided, the smallest diameter of which is smaller than the diameter of the electrical conductor, and at least one contact lug, the free end of which adjoins the passage, is designed such that when an electrical conductor is inserted, the contact lug at its free end rests against the electrical conductor. A passage refers to the region through which the electrical conductor may be inserted by use of the contact element. The passage is essentially delimited by the free ends of the contact lugs, regardless of whether the contact lugs lie in the plane of the base element or are bent outward from the plane of the base element. On the one hand the contact element is very easily manufactured, since it can essentially be fabricated from a flat, for example rectangular, electrically conductive piece of material in which the passage and the at least one contact lug are punched into the base element by means of a punching process. On the other hand, a very simple possibility is afforded for connecting an electrical conductor, since the electrical conductor need only be inserted into the opening, whereby the contact lug, if it still lies in the plane of the base element after the manufacturing process, is bent outward from the plane of the base element, or, if it is already bent outward from the plane of the base element by a certain angle, the contact lug is bent further upward until its free end rests against the electrical conductor, thereby ensuring electrical contact of the electrical conductor. For this reason the contact lugs are preferably designed as leaf spring-like elements. In addition, the electrical conductor can be removed from the contact element only with great difficulty, thereby allowing the electrical conductor to be secured. Furthermore, the contact element according to the invention has the advantage that it may be mounted on the printed circuit board using customary pick-and-place devices, and may be soldered in the reflow process.
It is preferred that two to eight contact lugs at their free ends adjoin the passage, thereby ensuring a good electrically conductive contact between the electrical conductor and the contact element via multiple contact points.
In one advantageous refinement of the invention, multiple, preferably at least three, passages are provided in the base element, so that multiple, preferably at least three, electrical conductors may be connected in a base element, thus allowing an electrically conductive connection between multiple electrical conductors. The contact element is therefore particularly suited as a shorting clip.
The contact element is preferably designed as a punched element, thus allowing particularly simple manufacture of the contact element.
The contact element may be mounted on a printed circuit board in a particularly simple manner, for example using the SMD technique, by placing the flat contact element on a corresponding contact surface of the printed circuit board and fastening it at that location by soldering, for example. Alternatively, the contact element additionally has at least one connecting pin, preferably perpendicular to the plane of the base element, by means of which the contact element may be fastened to a printed circuit board in the perforation technique. In both alternatives the contact element may be mounted directly on the printed circuit board, thus allowing a compact contact.
In one advantageous refinement of the invention, the contact element is situated in an insulating housing, and input openings are provided in the housing in such a way that the electrical conductor may be pushed through the input openings of the housing and into the passages in the base element. The insulating housing has the advantage that release openings may also preferably be provided therein so that a release tool may be pushed through same against at least one contact lug for the base element in order to deflect the at least one contact lug and release it from the inserted electrical conductor to enable removal of the electrical conductor from the contact element without damage. The release tool may be a screwdriver, for example, by means of which the contact lug is merely pushed away from the electrical conductor. However, it is preferred that in at least one release opening a release tool is provided which has an end to be applied to the contact lug, and an actuation end which may be displaced in the release opening, the end to be applied against the contact lug being situated in the housing and the actuation end being situated outside the housing. The release tool is thus permanently installed in the release opening, so that it is not necessary to find an appropriate tool when the electrical conductor is to be released from the contact element.
The release tool preferably has a wedge-shaped design at the end to be applied against the contact lug to enable particularly simple engagement between the electrical conductor and the contact lug resting against the electrical conductor, or between multiple contact lugs resting against the electrical conductor, and to enable the contact lug(s) to be pushed away from the electrical conductor to allow removal of the electrical conductor from the contact element without resistance.
The contact element according to the invention is preferably used for connecting an electrical conductor. The electrical conductor is designed in particular as a connecting wire, and is preferably connected to a printed circuit board.
In the method according to the invention for connecting an electrical conductor, first an electrically conductive contact element is mounted on a substrate element, for example a printed circuit board or an insulating housing, the contact element having a passage whose smallest diameter is smaller than the diameter of the conductor, whereby at its free end at least one contact lug adjoins the passage. The conductor is then guided through the passage, whereby the at least one contact lug, if it still lies in the plane of the base element during the manufacturing process, is bent outward from the plane of the base element, or, if the contact lug is already bent outward from the plane, it is bent further upward until its free end rests against the electrical conductor. The electrical conductor is then held in a clamped manner by the at least one contact lug, thereby establishing the electrical contact via the contact lug for the contact element.
The invention is explained in detail with reference to the figures, which show the following:
a shows a perspective view of a first exemplary embodiment of a contact element;
b shows a perspective view of a second exemplary embodiment of a contact element;
c shows a perspective view of a third exemplary embodiment of a contact element;
d shows a perspective view of a fourth exemplary embodiment of a contact element;
e shows a perspective view of a fifth exemplary embodiment of a contact element;
f shows a perspective view of a sixth exemplary embodiment of a contact element;
a shows a schematic illustration of the step of mounting a seventh exemplary embodiment of a contact element on a printed circuit board;
b shows a schematic illustration of the step of inserting an electrical conductor into the contact element mounted on the printed circuit board, according to
c shows a schematic illustration of the electrical conductor connected to the printed circuit board via the contact element, according to
a shows a perspective view of a component to be connected to a printed circuit board;
b shows a component according to 3a in the state of connection to the printed circuit board;
a shows a partial cutaway perspective view of the contact element according to
b shows a perspective view of the housing together with the contact element according to
a shows a perspective view of a modified embodiment of the housing according to
b shows a partial cutaway perspective view of the housing together with the contact element according to
a shows a perspective view of a first exemplary embodiment of a connecting clip together with a contact element according to
b shows a partial cutaway perspective view of the connecting clip according to
a shows a partial cutaway perspective view of a second exemplary embodiment of a connecting clip together with a contact element according to
b shows a perspective view of the connecting clip according to
c shows another partial cutaway perspective view of the connecting clip according to
a through 1f show perspective views of six different exemplary embodiments of a contact element 10.
The contact element 10 according to a first exemplary embodiment illustrated in
b shows a second exemplary embodiment of the contact element 10, in which the base element 12 of this contact element 10 has no side walls, and instead is composed only of a flat, essentially rectangular, metal sheet. In the base element 12 a passage 14b is provided which is adjoined by three essentially triangular contact lugs at the free ends 18b thereof. The free end 18b of each of the contact lugs 16b is formed by one of the tips of the triangle which forms the contact lug 16b, whereas the contact lugs 16b are connected to the base element 12 at their sides oppositely situated from the tip. The contact lugs 16b and the passage 14a may in turn be punched from the base element 12 in a simple punching process. The tip which forms the free end 18b of the contact lugs 16b is blunt, the passage 14b being essentially formed by the blunt tips and imaginary connecting lines between each pair of adjoining free ends 18b. The smallest diameter 15b of the passage 14b thus formed is smaller than the diameter of the electrical conductor which is to be connected in the contact element 10, so that when an electrical conductor is pushed into the passage 14b, assurance is provided that the free ends 18b of the contact lugs 16b for the contact element 10 lie against the electrical conductor. To this end, the contact lugs 16b have a spring-like design in the manner of a leaf spring to ensure contact with the electrical conductor by elastic force.
A third exemplary embodiment of the contact element 10 is shown in
The distance between the free ends 18c of oppositely situated contact lugs 16c defines the smallest diameter 15c of the passage 14c, and in turn is smaller than the diameter of an electrical conductor to be inserted.
According to a fourth exemplary embodiment in
e illustrates an additional, fifth exemplary embodiment of the contact element 10, whereby in the essentially rectangular base element 12 of the contact element 10 four passages 14e are provided which are adjoined by the free ends 18e of each pair of essentially rectangular, preferably square, preferably leaf spring-like contact lugs 16e. After being formed by a punching process in which an essentially H-shaped punched opening is necessary, the contact lugs 16e are bent outward from the plane of the base element 12. In this manner a distinct insertion device is provided, since the electrical conductor can then be inserted only from the side into which the contact lugs 16e do not project. The passage 14e in each case is delimited essentially by the free ends 18e and each pair of imaginary connecting lines between the corners of the oppositely situated free ends 18e. The distance between the free ends 18e of each pair of contact lugs 16e adjoining one of the passages 14e defines the smallest diameter 15e. This diameter is smaller than the diameter of an electrical conductor to be connected. Thus, when an electrical conductor is inserted, the free ends 18e of the essentially rectangular contact lugs 16e lie against the electrical conductor. The contact element 10 according to the exemplary embodiment in
A sixth exemplary embodiment of the contact element 10 is illustrated in
a through 2c schematically illustrate the various steps for connecting an electrical conductor to a printed circuit board.
b illustrates an electrical conductor 30 to be connected, having an electrically conductive core 34 which is encased with insulation 32. The diameter of the electrically conductive core 34 is considerably larger than the smallest diameter 15g of the passage 14g, but approximately corresponds to the diameter of the passage [sic; opening] 22. The electrical conductor 30 must be pushed into the opening 22 from the side of the printed circuit board 20a, which is opposite from the side on which the contact element 10 is situated, since only in this way is it ensured that the contact lugs 16g can be bent outward from the plane of the base element 12.
c illustrates the electrical conductor 30 connected in the contact element 10. The electrically conductive core 34 of the conductor 30 has been pushed through the opening 22 in the contact surface 23 of the printed circuit board 20a, thereby bending the contact lugs 16g outward from the plane of the base element 12 of the contact element 10. The free ends 18g of the contact lugs 16g slide for a distance along the electrically conductive core 34, and are pressed against the core 34 by elastic force and form the electrically conductive contact between the core 34 of the conductor 30 and the contact element 10, thus forming the contact surface 23 and the printed conductor 21 for the printed circuit board 20a. Electrical conductors may thus be connected to printed circuit boards in a particularly simple manner, since the electrical conductors need only be pushed into the contact element 10, and additional soldering is unnecessary.
By use of the contact elements 10 it is possible to connect not only individual electrical conductors, which may be formed from wire, for example, but also to connect entire components 40, as shown in
a and 4b show the contact element 10 in the embodiment illustrated in
a and 5b show a housing 50′ which is a modified embodiment of the housing 50 shown in
a and 6b illustrate in a perspective view and in a partial cutaway view, respectively, a housing 60 in which a contact element 10 according to the exemplary embodiment illustrated in
Instead of a separate release tool 66 as illustrated in
Number | Date | Country | Kind |
---|---|---|---|
10 2006 028 814.9 | Jun 2006 | DE | national |