Patent Publication Number: US-6215380-B1

Title: Electromagnetic relay

Description:
BACKGROUND INFORMATION 
     An electromagnetic relay is described in German Patent No. 34 23 270. The relay includes a magnet system and a base group. Each of these modular units can be manufactured separately, so that functional testing and measurement tests can be carried out separately for each modular unit. Modular units which have been thus prepared are joined together in an assembly process, contact being created between electrical components and connector elements assigned to a base plate of the base group. 
     The base plate has recesses that leave space on either side of a given connector element in the area around a contact, this being designed as a weld point, so that a welding tool can be introduced. 
     If the contact between a connector element and a component is created in this way, the relay is more difficult to manufacture, as additional material is required for welding, stray particles and spatter have to be collected, and the tolerance for the position of the weld is very narrow. 
     To ensure that the welding machine can gain access to the location to be contacted, the base plate has recesses which leave space on either side of the connector element in the area around the weld point, so that a welding tool can be introduced. This is a disadvantage, as the relay has a large unit size. 
     SUMMARY OF THE INVENTION 
     The electromagnetic relay according to the present invention has the advantage that the aforementioned shortcomings can be avoided to a satisfactory degree. 
     To accomplish this, the base plate of the base group has a recess, which is largely filled when a component having a component wire is inserted and which is used to fix the component having the component wire in position. 
     A connector element, designed as a flat pin, has a hole that is created directly in the connector element, no additional material being required. When the flat pin is inserted into the base plate, this hole grasps the component wire that is fixed in position there, contact being created with the formation of an electrical contact. 
     An electrical contact created in this way is inexpensive to manufacture. It can be created without using additional material, and allows a small, compact relay to be manufactured, as no additional space is required on the base plate for the tool that creates the contact. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the electrical relay in a first side view as a partial section. 
     FIG. 2 shows the electrical relay in a second side view that has been rotated by 90° relative to the first, also as a partial section. 
    
    
     DETAILED DESCRIPTION 
     An electromagnetic relay  11  according to FIGS. 1 and 2 has a trough-shaped plastic housing  12  into which a magnet system  13  and a base group  14  can be inserted. 
     Magnet system  13  essentially includes an L-shaped angled magnet  16  and a magnet core  17 , which bears a winding carrier  18 , which is made of insulating material and has an energizing winding  19 . One of the arms of angled magnet  16  is riveted to the rear end of magnet core  17 . At the free end of the other arm, a bearing for a clapper-type armature  22  is formed by a leaf spring  21 . At the free end of leaf spring  21 , a switching contact  23  is provided which creates the contact with a make contact  24  located opposite when clapper-type armature  22  is pulled. In addition, magnet system  13  has two flat pins  27 , each of which is designed as a connector element  26 , which are pressed into winding carrier  18 . 
     Base group  14  essentially includes a base plate  28  which is made of insulating material and in which connector elements  26  are seated or can be mounted. In addition, base group  14  has a component  29  having a component wire  31 , which are fixed in position in a recess  32  of the base plate. Component  29  can, for example, be embodied as a resistor or a free-wheeling diode and may be connected to or connectable to a connector element  26  via a further component wire (not shown). 
     Each of the flat pins  27  is part of the separately manufactured modular unit of magnet system  13 . Each one has a contact section  33  which, when a relay  11  has been fully assembled, protrudes from housing  12  to create a contact with an assigned mating contact (not shown). 
     The other part of flat pin  27  forms a connection section  34 , which can be mounted in base plate  28  of the separately manufactured modular unit of base group  14 . Connection section  34  has a hole  36  having a sharpened edge  37  on tongue that protrudes laterally with respect to the longitudinal extension of connection section  34 . 
     Magnet system  13  is assembled in one assembly step by being pushed onto base plate  28 , which has been prepared with component  29 , component wire  31  and make contact  24 , recess  32  in base plate  28  being, in the area around component wire  31 , in the form of a groove  38 , into which connection section  34  of flat pin  27  having hole  36  can be pressed. Herein, component wire  31  is grasped by connection section  34  and, via sharpened edge  37 , creates electrical contact  39  with flat pin  27 , this being an insulation displacement connection. 
     By using an appropriate design for base plate  28  in the area around contact  39 , e.g., a resilient spring tongue, it can be ensured that the bias voltage remains largely constant at contact  39  for the entire life of the relay. In addition, this means the manufacturing tolerances at contact  39  can be relatively approximate, which is favorable in manufacturing terms. 
     In the case of this embodiment of contact  39 , a fused joint such as a soldered or welded joint is not required. As contact  39  is easy to create by joining together magnet systems  13  and base group  14 , relay  11  can be manufactured inexpensively with low manufacturing complexity, and unit sizes do not need to be large.