Abstract:
An electromagnetic switching relay having a base member and a magnetized coil. The base member having first guide elements. The magnetized coil having a terminal and second guide elements positioned substantially between the first guide elements that engage the first guide elements. A partition layer that allows displacement of the magnetizing coil relative to the base member before the second guide elements engage the first guide elements and fixes the second guide elements to the first guide elements when the base member and the magnetized coil are pushed toward each other.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to an electromagnetic switching relay. More particularly, the invention relates to an electromagnetic switching relay having guide elements that accurately align a magnetising coil with a base member to ensure proper spacing for an armature to interact with a switch contact. 
     DESCRIPTION OF THE PRIOR ART 
     Conventional electromagnetic switching relays have a base member on which a magnetising coil, a magnet core, a yoke and an armature are arranged. The armature interacts with a switch contact that is adjustable between a contact position in which the switch contact connects a first and a second terminal, and a release position in which the switch contact disconnects the first and the second terminal as a function of a current flowing through the magnetising coil. Electromagnetic switching relays of this type are known in the most varied of embodiments and are used, for example, in motor vehicle engineering. The known switching relays differ, in particular, with regard to the manner in which the mechanical relay parameters thereof are adjustable. 
     The described relays may comprise a magnetic bistable as well as a monostable magnetic circuit. Two switching positions with open and closed contacts are held by spring magnet or permanent magnet forces resulting from the insertion of a permanent magnet into the magnetic circuit. If the contacts are closed, the magnetic retention forces are generated by a permanent magnet in the bistable type or by the current-carrying coil in the monostable relay. The bistable magnetic circuit is weakened or strengthened by means of magnetic coils with opposite magnetic orientation, in order to obtain alternating switching positions. This is achieved by means of two coils with opposite windings or by electrical polar reversal. 
     One example of an electromagnetic relay having adjustable mechanical relay parameters is disclosed in DE 199 20 742 A1. DE 199 20 742 A1 teaches an electromagnetic relay having a base member, a magnet system and an armature spring. The magnet system has an armature on which two lever portions are formed constituting the support points for the armature spring. A further support point for the armature spring is located on a fixed relay portion. By bending the fixed relay portion the armature and, therefore, the contact spacing can be adjusted. 
     Because of unavoidable manufacturing tolerances, the spacing between the switch contact and the terminals does not correspond exactly to a desired value, but rather is subject to manufacturing-based variations. As a result, individual and generally manual adjustment of the contact spacing is required wherein, for example, either the magnet core is indented or a contact spring connected to the armature is bent. These known methods are time consuming and complex, and there is a risk that the adjusted contact spacing and overtravel will not remain constant, for example, owing to an elastic recovery from the plastic region of the contact spring. 
     It is therefore desirable to provide an electromagnetic switching relay that is simple in design and allows reliable and constant adjustment of contact spacing and overtravel for accurate arrangement of a magnetising coil with respect to the fixed contacts. 
     SUMMARY OF THE INVENTION 
     The invention relates to an electromagnetic switching relay having a base member and a magnetised coil. The base member having first guide elements. The magnetised coil having a terminal and second guide elements positioned substantially between the first guide elements that allow displacement of the magnetising coil relative to the base member and engage the first guide elements to fix the magnetising coil relative to the base member. 
     The invention further relates to a method for accurately arranging a magnetising coil in an electromagnetic switching relay. The magnetising coil is positioned relative to a base member by displacing the magnetising coil along first guide elements on either side of the base member and the magnetising coil. The magnetising coil is fixed relative to the base member by exerting a vertical pressure force on a partition layer by the magnetising coil or the base member. 
     An advantageous embodiment comprises a partition layer that is in one piece with a base member plate. 
     In a preferred embodiment the partition layer is incorporated at opposite longitudinal sides of a shaft. Preferably, the partition layer is a surrounding rim in a shaft of the base member plate. 
     In another preferred embodiment the guide elements have the shape of locking runners, whereby one locking runner comprises at least one longitudinal strut and one transversal strut. 
     Furthermore, it is advantageous to provide several transversal struts which are incorporated in opposite position at two longitudinal sides of the longitudinal strut. 
     The transversal struts preferably comprise a slanted plane which is inclined in an upward direction towards the longitudinal strut. The slanted plane allows for low-force locking between the transversal struts and the partition layer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top perspective view of an electromagnetic switching relay according to the invention shown without a housing; 
     FIG. 2 is a bottom perspective view of the switching relay of FIG. 1; 
     FIG. 3 is a schematic view along line III—III of FIG. 1; 
     FIG. 4 a  is a schematic diagram showing guide elements of a magnetising coil and a base member during positioning; 
     FIG. 4 b  is a schematic diagram showing the guide elements of the magnetising coil and the base member in a fixed position, 
     FIG. 5 is a further embodiment of the switching relay with a base member plate, 
     FIG. 6 is another switching relay without a base member plate with locking runners, 
     FIG. 7 shows in detail the transversal strut, and 
     FIG. 8 is a base member plate with shafts and partition layers at the side walls of the shafts. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2 show an electromagnetic switching relay  1 . The electromagnetic switching relay  1  comprises a base member  2  having terminals  3   a ,  11 ,  12 , a magnetising coil  3 , a yoke  6 , an armature  7  and a magnet core  4 . As shown in FIG. 3, the magnet core  4  is positioned between the magnetising coil  3  and adjacent to a permanent magnet  5 . The yoke  6  is substantially adjacent to the permanent magnet  5  and extends parallel to the magnet core  4 . The yoke  6  rests upon a portion of the magnetising coil  3  and has yoke mandrels  6   a  extending therefrom. The armature  7  is positioned adjacent to the yoke mandrels  6   a  and at a leading end of the magnetising coil  3  opposite from the permanent magnet  5 . 
     As shown in FIGS. 1 and 2, the armature  7  has bearing recesses  7   a , an armature tongue  7   b  and a contact spring  9 . The bearing recesses  7   a  are provided at an upper lateral edge region of the armature  7  for receipt of the yoke mandrels  6   a . The yoke mandrels  6   a  are arranged such that the armature  7  is mounted on the leading end of the magnetising coil  3  and is supported on the yoke mandrels  6   a.    
     As shown in FIGS. 1 and 2, the contact spring  9  is designed as a cruciform leaf spring having an integrally formed first leg  9   a  and second leg  9   b . The first leg  9   a  has a first free end connected to the armature tongue  7   b  and a second free end having a contact bridge  10 . The contact spring  9  presses the contact bridge  10  to contact faces of terminals  11 ,  12  as a function of the position of the armature  7 . The second leg  9   b  has elastic spring arms that extend from the first leg  9   a  that have free ends rigidly connected to the armature  7  by riveted joints  8 . 
     As shown in FIGS. 4 a  and  4   b , the base member  2  and the magnetising coil  3  have guide elements  13 ,  14 , respectively. The guide elements  13  of the base member  2  are designed as shafts  13   a  formed in the longitudinal direction of the base member  2 . The guide elements  14  of the magnetising coil  3  are formed as runners  14   a  on the lower side of the magnetising coil  3  facing the base member  2 . The runners  14   a  engage the shafts  13   a.    
     As shown in FIG. 4 a, a  partition layer or a type of film skin  15  is provided between the guide elements  13 ,  14 ,  13   a ,  14   a . The partition layer  15  is provided on either side of the guide elements  13 ,  14 ,  13   a ,  14   a  and is formed in such a way that the partition layer  15  irreversibly deforms or partially tears as soon as a vertical pressure force is exerted on the partition layer  15  via the base member  2  and/or the magnetising coil  3 . In addition to fixing of the magnetising coil  3  by deforming or tearing the partition layer  15 , it is possible to further fix the guide elements  13 ,  14  by a further fixing means, for example, casting the shafts  13   a  with a hardening material. 
     The attachment of the magnetising coil  3  to the base member  2  will now be described in greater detail with reference to FIGS. 4 a  and  4   b . As shown in FIG. 4 a , the runners  14   a  of the magnetising coil  3  are placed adjacent to the shafts  13  of the base member  2  such that the magnetising coil  3  can be displaced horizontally relative to the base member  2 . Once the magnetising coil  3  is arranged in the correct position relative to the base member  2 , the magnetising coil  3  is fixed in position by applying a vertical pressure force on the partition layer  15  by the base member  2  and/or the magnetising coil  3  to cause the runners  14   a  to penetrate the partition layer  15 . As shown in FIG. 4 b , the partition layer  15  formed between the guide elements  13 ,  14 ,  13   a ,  14   a  irreversibly deforms or partially tears as soon as the vertical pressure force is exerted on the partition layer  15  to fix the magnetising coil  3  in position and limit horizontal displacement. 
     The operation of the electromagnetic switching relay  1  will now be described in greater detail with reference to FIGS. 1 through 3. As the armature  7  rests on the yoke mandrels  6   a , the armature  7  tilts about an axis formed by the upper side of the yoke  6 . As shown most clearly in FIG. 3, in a rest position, the armature  7  is pulled by the permanent magnet  5  in the direction of the magnetising coil  3  such that the contact spring  9  is also in a rest position. In the rest position the contact bridge  10  rests on the contact faces of the terminals  11 ,  12  to produce an electrical connection between the terminals  11 ,  12 . The electromagnetic switching relay shown in FIG. 3 is a bistable relay. Depending on the embodiment, the relay may also be constructed as a monostable switching relay without a permanent magnet  5 . 
     When the magnetising coil  3  is supplied with a current, through the terminals  3   a, a  magnetic field is produced compensating the holding force of the permanent magnet  5  of the armature  7 . The armature  7  is, therefore, no longer pulled by a magnetic field toward the magnet core  4  and the bearing faces of the terminals  11 ,  12 . Consequently, the contact of the armature  7  on the magnet core  4  is broken by the contact spring  9  as the contact bridge  10  of the armature  7  pivots away from the magnet core  4 . As a result, the electrical connection between the contact bridge  10  and the terminals  11 ,  12  is interrupted. 
     Advantageously, the arrangement of the guide elements  13 ,  13   a ,  14 ,  14   a  and of the partition layer  15  between the guide elements  13 ,  13   a ,  14 ,  14   a  allows accurate positioning and durable fixing of the magnetising coil  3  relative to the base member  2 . Accurately positioning the magnetising coil  3  relative to the base member  2  ensures that the contact spacing between the contact bridge  10  and the contact faces of the terminals  11 ,  12  is large enough that the magnet core  4  magnetised by the permanent magnets  5  can attract the armature  7  and detract the armature  7  as a function of the current flowing through the magnetising coil  3 . 
     This arrangement of the magnetising coil  3  is also important in electromagnetic switching relays  1  without the permanent magnet  5  wherein the contact bridge  10  is at a distance from the terminals  11 ,  12  in the state without current, and a magnetic field is only produced when current flows through the magnetising coil  3  to cause the armature  7  and, therefore, the contact bridge  10  to be pulled toward the magnetic core  4  and the contact faces of the terminals  11 ,  12 . 
     In a simple embodiment it is sufficient to provide guide elements  13  that interact with the partition layer  15 . In this embodiment, it is not necessary to provide shafts as guide element. 
     FIG. 5 shows a bottom view of another embodiment of the invention with a further switching relay  20  with a base member plate  23 . Near its electrical terminals, the base member plate  23  incorporates first shafts  24  arranged at opposite longitudinal edges. The cross-section of the first shafts  24  is essentially rectangular and they are arranged alongside the longitudinal side of the base member plate  23 . From the upper side of the base member plate  23  first locking runners  23  are inserted into the first shafts  24 . First locking runners  21  comprise a longitudinal strut  27  and several transversal struts  26 . The longitudinal strut  27  is arranged alongside the first shaft  24 . The transversal struts  26  are arranged at right angles to the longitudinal direction of the longitudinal strut  27 . Preferably, two transversal struts  26  are provided on opposite sides at the longitudinal strut  27 . The first shafts  24  comprise a partition layer  15  at each longitudinal side. This partition layer has the shape of a longitudinal strip. In this manner, two facing partition layers  15  in the shape of longitudinal strips are arranged at the longitudinal sides of the first shafts  24 . The partition layers  15  are preferably in one piece with the base member plate  23 . Preferred materials are synthetics which provide the thickness required for the rigidity of the base member plate  23 , but can also be produced as a thin layer to allow for the desirable characteristics of the partition layer  15 . An essential function of the partition layer  15  is the locking of the first locking runners  21 , which is achieved by pressing down the first locking runners  21 . In this process, the transversal struts  26  create a deadlock of the first locking runner  21  with the partition layer  15 . Alternatively, they may also cut open the partition layer  15  in the area of the transversal struts  26 , thereby resulting in a form-closed interlocking between the transversal struts  26  and the cutup partition layer  15 . 
     At one edge of the base member plate  23  belonging to the armature, two second shafts  25  are incorporated into the base member plate  23 . The cross-section of the second shafts  25  is also rectangular and the second shafts  25  are arranged in their longitudinal direction alongside the longitudinal sides of the base member plate  23 . The second shafts  25  also comprise partition layers  15  on their insides. The partition layers  15  have the shape of marginal strips. Contrary to the first shafts  24 , the second shafts  25  are shorter. From the upper side of the base member plate  23 , second locking runners  22  are inserted into the second shafts  25 . The second locking runners  22  are also shorter than the first locking runners  21 . The second locking runners  22  also comprise a longitudinal strut  27  and transversal struts  26  and have the same shape as the first locking runners  21 . 
     FIG. 6 shows a bottom view of a further switching relay  20  without the base member plate  23 . The further switching relay comprises a relay casing  28 , which comprises at four corners of its bottom side the two first locking runners  21  and the second two locking runners  22 . This view clearly shows the shape of the longitudinal struts  27  as well as the shape of the transversal struts  26 . The top plane of the first and the second locking runner  21 ,  22  is indicated by an end plane  29  of the longitudinal strut  27 . The transversal struts  26  exhibit a slanted section at their upper end which is directed upwards towards the end plane  29  of the longitudinal strut  27 . 
     The first and second locking runners  21  incorporate several transversal struts  26  on both longitudinal sides of the longitudinal strut  27 . In a simple embodiment, however, it is sufficient to provide, for example, one single transversal strut  26  at one longitudinal side of the longitudinal strut  27 . Contrary to the disclosure of FIG. 6, the opposite transversal strut  26  may also be arranged in lateral displacement on both sides of the longitudinal strut  27 . 
     FIG. 7 shows a corresponding enlarged view of the longitudinal strut  27  with two transversal struts  26 . The advantage of the slanted plane  30  of the transversal strut  26  is the fact that when the first and the second locking runner  21 ,  22  are pressed with the slanted plane  30  through the partition layer  15 , the partition layer  15  can either be pressed apart or cut open more easily. On the whole, the slanted plane  30  makes it easier to press the further switching relay  20  into the partition layer  15 , thereby achieving an easier fixing of the further switching relay  20  to the base member plate  23 . The first and second locking runners  21 ,  22  are preferably in one piece with the relay casing  28 . As a preferred material for the construction of the relay casing as well as for the first and second locking runner  21 ,  22 , use is made of synthetics. 
     FIG. 8 is a top view of the base member plate  23  and clearly shows the first and second shafts  24 ,  25 . For better representation, the two shafts  25  are cut open in order to allow for a clear view of partition layers  15 , which are arranged alongside the longitudinal sides of the first and second shafts  24 ,  25 . The partition layers  15  are layers which extend from the longitudinal sides of the first and the second shafts  24 ,  25  in the direction of the opposite longitudinal side. The two opposite partition layers  15  of a first or second shaft  24 ,  25  have a fixed distance to each other. 
     Depending on the embodiment, the partition layer  15  may also be provided at only one longitudinal side of a shaft  24 ,  25 . In another embodiment, the partition layer seals the entire shaft  24 ,  25  in the shape of a plane. In this embodiment, the locking runners  21 ,  22  at least partially enter the partition layer  15  when pressing down the further relay  20  while fixing it to the base member plate  23 . Depending on the embodiment, the partition layer  15  may also be cut up when the further relay  20  is pressed down.