Abstract:
The invention relates to an electrical connector for connecting a contact pin to an electrical conductor. It is proposed that the insulator housing of the connector provide a connecting space, in which the contact pin and the electrical conductor can be plugged in opposite direction in roughly parallel alignment and overlap by their axial lengths, the conductor being able to move crosswise to its conductor axis within a range of movement permitted by the construction and the leaf springs of the conductor clamp connection pressing the conductor in the direction of the contact pin.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an electrical connector having an insulator housing, which has plug-in openings on two oppositely-lying sides of the housing, namely, on one side for inserting an electrical contact pin and on the other side for inserting the insulation-stripped end of at least one electrical conductor. On the pin side, the connector has a pin clamp contact, so that the connector can be plugged onto the contact pin of a circuit board or onto the connecting contact pin of another mating contact; and on the conductor side, the connector has a leaf-spring clamp connection with a leaf spring for each electrical conductor to be connected, which extends in the conductor plugging-in direction and oblique to the electrical conductor and, with its leaf spring end, firmly clamps the insulation-stripped end of the plugged-in electrical conductor. 
     Electrical conductors of this type were already described in 1976 in GB 1,528,993. There, they are presented as two-pole connectors, consisting of two one-pole connectors, which are arranged in a common block housing made of an insulator, so that the two-pole block housing connectors may be understood as a “plug and socket arrangement” in relation to two parallelly-positioned contact pins. According to GB 1,528,993, socket clamp contacts are provided for plugging the connector onto the contact pins and are to be designed in such a way that, if need be, the connector can be again pulled off the contact pins. It is also provided that the leaf-spring clamp connections present on the other side of the connector can also be again opened for the electrical conductors if need be by using a tool to press back the leaf springs of the leaf-spring clamp connections, so that the electrical conductors can be pulled out again from the connector. 
     Another connector of this type is known from EP 0 735 616 A2 (see therein FIGS. 18 and 19). It is referred to as an “electrical plug connector,” which can be plugged onto the soldered contact pins of a circuit board and, in consequence of a tulip-shaped spring-back socket clamp contact, can be again pulled off the contact pins. Present on the other side of the connector, in turn, is a leaf-spring clamp connection for the electrical conductor, which is also designed as a releasable leaf-spring clamp connection (as in GB 1,528,993). 
     Both of the aforementioned connectors assume that their pin clamp contacts and their conductor clamp connections are fabricated in their entirety from one piece of spring steel sheet, the piece of spring steel sheet being shaped on the pin side to produce a socket clamp contact and forming on the conductor side an integrated leaf-spring clamp connection for the electrical conductor. Between the two sides, the piece of spring steel sheet takes on the current-conducting function, so that, in choosing the material, attention must be paid also to a useful current-conducting capacity of the spring steel sheet, which, in turn, is reflected in the material costs of the spring steel sheet. 
     In regard to the design of their construction, the two aforementioned connectors are designed in such a way that the pin clamp contact, on the one hand, and the conductor clamp connection, on the other hand, are arranged at an adequate distance apart, so that the two sides do not mutually interfere with each other. The insulator housings of these known connectors are to be accordingly large in dimension. 
     The problem of the invention is to create a connector of the type mentioned above, which can be produced cost-effectively and the size of which can be substantially reduced, so that it can also be employed in narrow spaces both as a one-pole and as a multipole connector. 
     SUMMARY OF THE INVENTION 
     This problem is solved in accordance with the invention by having the insulator housing of the connector provide a connecting space for each electrical conductor to be connected, into which the contact pin and the electrical conductor can be plugged adjacently in roughly parallel alignment, the contact pin and the electrical conductor overlapping in their axial lengths. In doing so, the contact pin is held in fixed position in the connecting space, whereas the electrical conductor can move crosswise to its conductor axis within a range of movement permitted by the construction (preferably, it can move parallel), whereby the leaf-spring end of the leaf-spring clamp connection is adjacent to that side of the electrical conductor that lies opposite the contact pin, so that the clamping force of the leaf spring presses the electrical conductor in the direction of the contact pin. 
     There are two fundamental embodiments of the connector in accordance with the invention. 
     In the first embodiment, the electrical conductor contacts the contact pin directly, so that this embodiment requires no additional current-conducting material between the electrical conductor and the contact pin for purposes of current conduction. This reduces cost and saves material. This embodiment of the connector is preferred for single-wire, solid electrical conductors, because these can be inserted into the connecting space of the connector without prior opening of the leaf-spring clamp connection. 
     The second embodiment of the new connector is preferably recommended for multiwire flexible electrical conductors, in which, in the conventional way, the leaf-spring clamp connection can be opened before the flexible conductor is inserted into the connecting space of the connector. This embodiment of the connector has the special feature that a contact wall is positioned between the electrical conductor and the contact pin in the region of their mutual axial overlap and this wall guides the electrical conductor in the direction of its conductor axis into the connecting space during the plugging-in operation and does so, namely, preferably all the way into a bottom-side conductor catch recess that is open toward the contact wall. This contact wall guide prevents the undesired splicing of individual wires of a multiwire flexible conductor. The contact wall can move in the direction of the contact pin, jointly with the electrical conductor, within a range of movement permitted by the construction crosswise to the conductor axis of the electrical conductor, so that the electrical conductor contacts the contact wall directly and the contact wall contacts the contact pin directly. 
     A connector having the above features can be produced extremely cost-effectively. For the new connector, only a small piece of spring steel sheet has to be used—namely, exclusively for the formation of the leaf-spring clamp connection. The needed materials required for this can be substantially reduced, especially when the leaf spring of the leaf-spring clamp connection is propped against the insulator housing of the connector. In this regard, it is proposed that the leaf-spring clamp connection has a U-shaped, bent, two-arm leaf spring, which has a leaf-spring clamp arm and a leaf-spring retaining arm, the leaf-spring retaining arm being held in position in the insulator housing of the connector by engaging with the insulator housing. 
     In regard to the required reduction in the size of construction of the connector, the teaching of the invention includes the fact that the axial lengths of the contact pin and of the electrical conductor to be plugged into the connector overlap. This overlap may be maximal in that the electrical conductor is inserted into the connecting space all the way to a bottom-side closing wall, so that the end of the electrical conductor can be guided near to the foot end of the electrical contact pin or of another connecting pin. This maximum overlap enables the height of construction of the connector to not be substantially greater than the plugging-in depth of the electrical conductor. 
     The new connectors may have one or two connecting spaces for electrical conductors per pole, only one contact pin being sufficient for one connector with two connecting spaces, when this pin is positioned in the middle between the connecting spaces and serves both connecting spaces as a contact pin. 
     The connectors in accordance with the invention can, in principle, be plugged onto any contact pin and/or connecting pin used in practice. It is preferred that the head end of the respective contact pin be fixed in precise position by way of an insulator overhang. This positional precision of the respectively used contact pin improves the contact seating of the electrical conductor at the contact pin. 
     The same purpose of positional precision of the contact pin is attained, wherein the foot end of the contact pin is held in fixed position against the insulator housing of the connector by means of a lateral support. 
     The contact pins, held in precise and fixed position in the insulator housing of the connector may, as desired by the post-processing industry, be plugged into the respective connecting spaces of the connector by the factory manufacturing the new connectors, so that, then, the post-processing industry can insert and solder the connectors with the foot-side projecting contact pins directly into, for example, the solder openings of a circuit board. 
     It is advantageous to use contact pins that are constructed, below their head end, with a convexity, the apex of which extends crosswise to the lengthwise axis of the contact pin. In connection with a contact line of an electrical conductor running in the direction of the lengthwise axis of the contact pin, there then results, at the point of intersection of the lines mentioned, a point-like physical contact having a higher specific surface pressure, which improves the current transfer at this point of contact. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Embodiment examples of the invention will be described below on the basis of drawings. Shown are: 
       FIGS.  1 + 2  a first embodiment example of a connector in accordance with the invention, 
         FIGS. 3-5  three further examples of embodiments, 
         FIGS. 6-8  two embodiment examples having a catch to prevent the contact pin from being pulled out of the connector housing, 
         FIGS. 9-15  two application examples of a connector in accordance with the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a cross section through a connector in accordance with the invention, which, namely, is in the state of being plugged onto a contact pin  3 , which is soldered in the circuit board  4 . The contact pin  3  has the convexity  5  and is positioned precisely in the connecting space  7  of the insulator housing  8  by means of the insulator overhang  6 . 
     The electrical conductor  9  is plugged from the top side into the connector. Arranged adjacently in the connecting space  7  of the connector are the contact pin  3  and the electrical conductor  9 , their axial lengths mutually overlapping. By means of the convexity  5 , the contact pin contacts the electrical conductor  9  directly, so that a direct current transfer takes place between the contact pin and the electrical conductor. 
     The electrical conductor  9  can move (as the housing depiction in  FIG. 1  shows) toward the left against the contact pin  3  by means of the spring force (clamping force) of the leaf spring  11 . The movement takes place within the range of movement  10  permitted by the construction. This ensures that the electrical conductor always lies in secure contact against the respectively used contact pin. 
     The leaf spring mounted to the connector is fabricated in a U shape from one piece of spring steel sheet and has a leaf spring clamping arm  11  and a leaf-spring retaining arm  12 . It is held in fixed position in the insulator housing with its head arch  13  and its retaining arm  12 . 
     Provided in the insulator housing of the connector, in the conventional way, is an inspection opening  14 . It is also possible to furnish the insulator housing with a press latch made of an insulator, which can be operated manually, if need be, in order to press the leaf-spring clamping arm  11  off the electrical conductor  9 , so that the clamping of the electrical conductor is released and the electrical conductor can be pulled out of the connector. The same result is also usually accomplished by using an actuating opening in the insulator housing, through which a tool (e.g., a screwdriver bit) can be inserted to reach the leaf-spring clamping arm  11 , as is also depicted, for example, in  FIG. 3 . 
       FIG. 2  shows, in a perspective view, a multipole connector of the type in accordance with the invention, having a block housing  15  fabricated from an insulator. The total of five one-pole connectors mounted in the block housing are identical in construction and each corresponds to the embodiment example according to  FIG. 1 . They are oriented alternately in relation to one another. This arrangement scheme saves space, but it may also be replaced by any other desired arrangement scheme. 
       FIG. 3  shows the perspective cross section of a one-pole connector in accordance with the invention, having a connecting space  16  that has special features for the connection of a multiwire flexible conductor  17 . The connecting space terminates on its left side at a contact wall  18 , which is positioned between the flexible conductor  17  and the contact pin  19  and can move in a range of movement  20  permitted by the construction crosswise to the conductor axis of the electrical conductor  17  and jointly with it in the direction of the contact pin  19  in order to ensure a good electrical contact between the contact pin, the contact wall, and the flexible conductor. The contact wall  18  guides the flexible conductor during the plugging-in operation all the way into a bottom-side conductor catch recess  21 , which is open toward the contact wall, thereby preventing individual wires from being spliced from the multiwire flexible conductor  17  during the plugging-in operation. The conductor clamping site between the leaf spring  22  and the contact wall  18  can be opened for connecting and releasing the electrical conductor by inserting a screwdriver bit via the actuating opening  23  into the connecting space and moving the leaf spring away from the electrical conductor by using the screwdriver bit. The conventional inspection opening is provided by reference  24 . 
       FIG. 4  shows a connector that is comparable to the connector according to  FIG. 1 , but in which the contact pin  25  plugged into the connecting space has a bottom support  26 , which is oriented toward the insulator housing of the connector and improves the positional precision of the contact pin in the connecting space. 
       FIG. 5  shows, in cross section, a one-pole connector in accordance with the invention, which has two connecting spaces for two electrical conductors  27  and  28  and can be plugged onto only one contact pin  29  for producing an electrical connection. The contact pin  29  is constructed mirror-symmetrically with respect to its lengthwise axis and thus serves both connecting spaces as the contact pin. It has on both sides, respectively, a support  30 , which ensures the positionally precise plugging of the connector onto the contact pin. 
     As a rule, the connectors are plugged onto the contact pin of a circuit board or onto the connecting contact pin of another mating contact (for example, to an electrical device). This can be conducted, as desired, before or after the connection of the electrical conductor to the connector. If need be—for example, in the event of a defect of a component wired to the connector—it is advantageous in terms of technical operation to pull the connector out from the contact pins and to replace the complete component group (for example, consisting of the defective component and the connector wired to the component) with a new component group. 
     In practice, there are also many cases of application for the new connectors, in which it is required that the connectors are not permitted to be pulled off of the contact pins; that is, a pull-out detent is to be present for the contact pin, so that the pin cannot be pulled out of the connecting space of the connector. This is depicted in  FIGS. 6 to 8 . 
       FIG. 6  shows a connector that is comparable to the embodiment example according to  FIG. 4 , but, in addition, has a pull-out detent for the contact pin, which, in this embodiment example, acts in the form of the barbed locking pieces  31  in the corresponding recesses of the insulator housing of the connector. 
       FIGS. 7 and 8  show two connectors, the insulator housings of which are constructed and formed in such a way that both connectors can be used jointly as an electrical plug connection. In their basic construction, the connectors  32  and  33  are comparable to the embodiment example according to  FIG. 4 , although, for the connector  32  depicted on the left, the contact pin  34  (which is common to both connectors) is fixed in place in the insulator housing  36  by use of a pull-out detent  35 , whereas, in the connector  33  depicted on the right, the insulator housing  37  can be pulled off of the contact pin  34  (which is common to both connectors) and the electrical plug connection that is shown can thereby be opened. 
       FIGS. 9 to 15  show two application examples for a connector according to the teaching of the invention in order to demonstrate that these can be used very well also for plug-in linking connectors that can be plugged onto angled contact pins, which, in turn, are soldered into a circuit board. 
       FIG. 11  shows a circuit board  38  into which, in an offset arrangement, a long angled contact pin  39  and a short angled contact pin  40  are respectively soldered, the offset arrangement ensuring that the soldering sites of the contact pin in the circuit board  38  have an adequate, that is, interference-free, distance from one another. 
     The connectors that can be plugged onto the angled contact pins are depicted in cross section in  FIG. 9  and  FIG. 10 .  FIG. 12  and  FIG. 13  show the connectors as 6-pole connectors  41  in a common insulator block housing.  FIG. 11  and  FIG. 12  show the 6-pole connector  41  prior to being plugged onto the angled contact pins of the circuit board  38 .  FIG. 13  shows the same 6-pole connector after the plugging operation. 
       FIG. 14  shows a circuit board  42  having angled contact pins (corresponding to the circuit board  38  in  FIG. 11 ), which is mounted in the housing of a lamp ballast  43  for electrical lamps in such a way that the 6-pole connector  44  in accordance with the invention can produce, without any problems and in a single plugging operation, all required conductor connections to the lamp ballast and to the lamp (see  FIG. 15 ).