Abstract:
In order to make a process available for the production of a position sensor comprising a housing, in the housing interior of which an electrical circuit arranged on a carrier is seated, which can be carried out with less time expended and inexpensively it is suggested that the carrier be connected to an electrical connection element to form a carrier-connection element combination, the carrier-connection element combination be introduced into the housing closed at a measuring end from the rear end located opposite the measuring end, the space around the carrier-connection element combination in the interior of the housing be filled with a molding compound up to a specific level and a cap be connected to the rear end of the housing, connections of the connection element being guided through this cap.

Description:
[0001]     This application is a continuation of commonly assigned, copending U.S. patent application Ser No. 09/812,112 filed on Mar. 15, 2001, which claims the benefit of German patent application no. 100 13 218.9 filed on Mar. 17, 2000, each of which is incorporated herein by reference in their entirety and for all purposes. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to a process for the production of a position sensor with a housing, in the housing interior of which an electrical circuit arranged on a carrier is seated.  
         [0004]     Furthermore, the invention relates to a position sensor comprising a housing for accommodating an electrical circuit arranged on a carrier in a housing interior and an electrical connection element.  
         [0005]     Position sensors of this type, such as, for example, inductive proximity switches, are also used in “difficult” environmental conditions, such as, for example, in a machine tool where they can be subjected to coolant, lubricant, machining chippings and the like. When such fluids or materials pass into the housing and reach the circuit, the operability of a position sensor may be impaired by this or it may even fail completely.  
         [0006]     2. Discussion of the Prior Art  
         [0007]     It is therefore known, for example, from WO 82/01630 or DE 195 04 608 A1 to provide the circuit with a sheathing consisting of a molding compound, such as a casting resin, in order to seal the circuit hermetically. As a result, the production of a position sensor is, however, complicated and expensive.  
       SUMMARY OF THE INVENTION  
       [0008]     The object underlying the invention is therefore to make a process available for the production of a position sensor specified at the outset which allows a production which is less complicated and thus quick and inexpensive.  
         [0009]     This object is accomplished in accordance with the invention, in the process specified at the outset, in that the following process steps are provided: 
        The carrier is connected to an electrical connection element to form a carrier-connection element combination;     the carrier-connection element combination is introduced into the housing closed at a measuring end from a rear end located opposite the measuring end;     the space around the carrier-connection element combination in the interior of the housing is filled with a molding compound up to a specific level; and     a cap is connected to the rear end of the housing, the connections of the connection element being guided through this cap.        
 
         [0014]     The inventive process offers a series of different advantages: Not only is the carrier and with it the circuit fixed in the interior of the housing as a result of the molding compound but also a connection element for closing the interior of the housing at the measuring end and also the cap in relation to the housing. No further steps need therefore be taken to fix the connection of the carrier with, for example, the closure element at the measuring end; the molding compound serves not only for the complete encasing of the circuit but also for fixing the components of the position sensor on the housing.  
         [0015]     As a result of the fact that the carrier-connection element combination is introduced into the housing from the rear end thereof and subsequently molding compound is cast into it, a relatively large opening space is available for the introduction of the carrier as well as for pouring in the molding compound and so the carrier can be introduced quickly and without any problem and the filling procedure may be carried out quickly and concertedly since molding compound need not be pressed in, in particular, via narrow channels. As a result, a homogeneous distribution of the molding compound may be achieved whilst continuing to avoid air pockets. As a result, a high dielectric strength of the position sensor produced according to the invention is ensured and so this has a high safety class.  
         [0016]     The carrier-connection element combination may be fixed in the housing due to the subsequent placement of the cap, namely, in particular, transversely to a longitudinal direction of the housing, wherein this fixing is brought about automatically with the connection to the cap. Since the connection element is already connected to the carrier element, the switch is finished once the cap has been placed in position and the molding compound hardened. In particular, the connection element does not have to be connected to the carrier in addition once the cap is already in place.  
         [0017]     Since the carrier is connected to the connection element in a mechanically stable manner, the cap may be used accordingly for a centering and fixing of the carrier via the carrier-connection element combination. As a result, a homogeneous distribution of the molding compound is again ensured and thus a high dielectric strength.  
         [0018]     The metal housing itself may be designed in a cost-saving manner since, in particular, no tapering to form a receiving means or for the fixing of a connection element need be provided since this task is attributed to the cap.  
         [0019]     Due to the molding compound being poured in from the rear end, a high safety class for the position sensor can also be achieved since a defined air path for preventing any breakdowns can be made available in a controlled manner, namely via the control of the amount of molding compound poured in and thus the level of the molding compound. By arranging a shrinkage tube to the air path, the dielectric strength may also be ensured with respect to the space free from molding compound.  
         [0020]     In this respect, the carrier-connection element combination is advantageously arranged in the housing at an angle to a longitudinal direction when molding compound is poured in. As a result, a large opening angle is available for the filling with the molding compound and so this can be poured in more quickly and more concertedly. The carrier-connection element combination is then leaned, in particular, against an inner wall of the housing when molding compound is poured in. Once the specified filling level is reached, the carrier-connection element combination is aligned again and the cap can then be placed in position. In this way, a quick filling with the filling compound effecting a hermetic sealing of the circuit can be achieved.  
         [0021]     The cited object is also accomplished in accordance with the invention, in the process specified at the outset, in that the steps: 
        the carrier is connected to an electrical connection element to form a carrier-connection element combination;     a molding compound is poured into the housing interior of the housing closed at a measuring end up to a specific level;     the carrier-connection element combination is pushed into the housing interior with the molding compound; and     a cap is connected to the rear end of the housing, the connections of the connection element being guided through this cap, are carried out one after the other.        
 
         [0026]     This inventive process differs from the process described above essentially due to the fact that the molding compound is first poured into an “empty” housing interior and only afterwards is the carrier-connection element combination pushed in. This has the advantage that the molding compound can easily be poured in since no components are in the way of the filling procedure.  
         [0027]     As for the rest, this process has the advantages already specified above.  
         [0028]     The connection element is favorably connected rigidly to the carrier and, in particular, in a mechanically secure manner. As a result, the carrier-connection element combination may be aligned via the connection element. This is advantageous because access is easiest to the connection element since this provides the connection to the surroundings. The cap is pushed onto the connection element, in particular, with an opening. The connection element is then seated in this opening at least partially and the carrier-connection element combination is, altogether, aligned and centered via the cap which is, on the other hand, connected to the housing.  
         [0029]     It is favorable when a plurality of contact pins of the connection element are connected to the carrier in order to thus provide for a secure connection between connection element and carrier. In this respect, it is particularly advantageous when the connection element is soldered to the carrier. As a result, a rigid and mechanically secure connection is ensured between carrier and connection element for forming the carrier-connection element combination.  
         [0030]     To simplify the production of the position switch it is advantageous when a cup-shaped insert is provided at the measuring end for closing the housing and this insert is pushed into the housing in the direction of the rear end from the measuring end. A closure element at the measuring end should not normally be manufactured from a metal since, otherwise, the results of measurement themselves could be influenced. The closure element cannot, therefore, be formed in one piece with the housing but rather it must be connected to the housing afterwards. Due to the design as a cup-shaped insert, the molding compound itself may then be used to provide for a good connection to the housing (in the housing interior) after insertion of the insert. Moreover, such a cup-shaped insert may be pushed into the housing in a simple manner. An additional, electrical insulation between housing and circuit is also brought about due to such an insert and thus the dielectric strength is increased considerably.  
         [0031]     In this respect it is favorable when the insert is held on the housing in a force-locking manner after its insertion. No further measures need then be taken during the insertion of the carrier-connection element combination and/or the pouring of the molding compound into the housing interior in order to clamp the insert with the housing so that this closure element is not detached from the housing due to any possible force acting during the insertion/filling; on the contrary, the corresponding design of the insert sees to it that this is not detached from the housing during the production of the position switch.  
         [0032]     In addition, it is favorable when the carrier-connection element combination is placed onto a closure element forming the closed measuring end when molding compound is poured in. It is guaranteed as a result that a corresponding sensor and, in particular, a coil is located at the front measuring end.  
         [0033]     In order to facilitate filling, the housing is favorably oriented in its longitudinal direction essentially parallel to the direction of gravity during the introduction of the carrier-connection element combination and/or the filling with the molding compound. As a result, it can also be ensured that essentially the entire free space in the housing interior is filled with molding compound.  
         [0034]     It is favorable when the amount of molding compound poured into the housing is controlled. As a result, it is possible for filling compound to be introduced into the housing interior up to a specific level in order to, for example, prevent too much molding compound being poured in or not enough molding compound being poured in.  
         [0035]     It is favorable when, during the connection of the cap with the housing, the carrier-connection element combination is aligned in longitudinal direction of the housing. As a result, it is possible to avoid the carrier-connection element combination being moved to too great an extent in the molding compound not yet hardened which, in certain circumstances, can lead to air pockets and a quick coupling of the cap to the housing is brought about. For this purpose, the carrier-connection element combination is, in particular, aligned essentially collinear to the longitudinal axis of the housing during the connection of the cap with the housing.  
         [0036]     A good connection of the cap with the housing may be achieved when the cap is pushed into the housing. As a result, it is also possible, with a hardened molding compound, for this to fix the cap against the housing since the molding compound can also pass between a space of the housing interior and the cap and is located between the carrier and the cap. When the cap is pushed into the molding compound which is not yet hardened, molding compound is displaced accordingly via buoyancy forces and care is taken that this fills all the spaces to a very large extent. As a result of the inserted cap, which insulates the housing from the circuit, the dielectric strength is also increased.  
         [0037]     The cap is favorably pushed into the housing as far as a stop defined on the cap. As a result, when a corresponding amount of molding compound is poured in it is also ensured that the entire circuit is essentially encased by hardened molding compound and the molding compound is present in the housing interior as far as a defined end.  
         [0038]     It is particularly advantageous when the cap is pushed into the housing prior to hardening of the molding compound. As a result, the molding compound can be used, after hardening thereof, to fix the cap on the housing and thus also to seal the housing interior in relation to the surroundings in the direction of the cap.  
         [0039]     In a variation of one embodiment it is provided for the cap to be positioned on the carrier-connection element combination prior to insertion of the carrier-connection element combination. The cap and the carrier-connection element combination are then pushed as a whole into the housing interior which has been filled accordingly with molding compound beforehand. The carrier may be positioned and fixed in the housing interior in the molding compound, in particular, with the step of connecting the cap with the housing. The carrier-connection element combination is then favorably pushed into the housing with the cap positioned, wherein this housing is filled with molding compound.  
         [0040]     It is particularly advantageous when the cap is provided with a fixing means and the connection element with a fixing means adapted thereto. This may, for example, be a tongue on the cap and a notch in the connection element which is adapted to this tongue. As a result, a good connection is provided between the cap and the connection element and thus between the cap and the carrier-connection element combination.  
         [0041]     Care must then be taken that during the connection of the cap with the housing the cap and the carrier-connection element combination are oriented relative to one another such that the respective fixing means can engage in one another, i.e., for example, the tongue can engage in the notch in order to provide for a relative fixing and, in particular, also non-rotational fixing between cap and carrier-connection element in this way.  
         [0042]     The object specified at the outset is accomplished in accordance with the invention, in a generic position sensor, in that the carrier and the connection element are rigidly connected to one another to form a carrier-connection element combination and a molding compound is arranged in a space between the carrier-connection element combination and an inner wall of the housing.  
         [0043]     Such an inventive position sensor may be produced in a simple manner since the molding compound may be poured into the housing via a large opening space and the carrier-connection element combination may be aligned as a whole on account of the mechanically secure connection between carrier and connection element and, in particular, only a cap still has to be pushed on to close the position sensor at the rear end and the connection element does not have to be subsequently connected electrically to the carrier.  
         [0044]     In this respect, the connection element is favorably a plug insert, with which a plug can be connected.  
         [0045]     It is particularly advantageous when the connection element is soldered to the carrier since a rigid, mechanically secure connection can be produced as a result.  
         [0046]     The housing is advantageously manufactured from metal. The housing has a high inherent stability as a result and protects the circuit from mechanical damage due to impacts and the like. In addition, the housing has a high stability with respect to environmental influences such as chemical substances, action on it due to heat, fluid and the like.  
         [0047]     It is particularly advantageous when the housing is closed at a measuring end with a cup-shaped insert. As a result, the inventive position sensor may be produced in a simple manner. The cup-shaped insert extends, in particular, over more than one third of the length of the housing and so it is held securely in this housing and, in particular, can also be fixed well on the housing by means of molding compound.  
         [0048]     The insert is advantageously manufactured from a plastic material. As a result, a measurement result is also not influenced, i.e. the insert cannot act as an inductive negative feedback with respect to a coil.  
         [0049]     A sealing element is favorably formed on the insert for sealing between the insert and the inner wall of the housing. On the one hand, this seal prevents fluids such as coolant and machining waste such as metal chippings from being able to pass into the housing interior from outside and liquid molding compound from being able to exit from the housing interior out of the front end (measuring end) during the production of the inventive position sensor.  
         [0050]     It is particularly advantageous when the insert is designed to be pushed into the housing so that it can be connected to the housing in a simple manner and, in addition, can be fixed on the housing additionally via molding compound.  
         [0051]     In order to facilitate the production of the inventive position sensor, the insert is favorably designed such that it can be positioned on the housing in a force-locking manner. No additional, for example, clamping means need than be provided during the production in order to prevent the insert from detaching from the housing.  
         [0052]     It is particularly advantageous when the housing is designed to be essentially rotationally symmetrical. The housing may then be produced in a simple manner.  
         [0053]     The production is simplified further to a great extent when the housing interior has essentially the same cross section over the length of the housing. Tubular elements can then, in particular, be cut off to a corresponding length and no expensive special production is required for the inventive position sensor.  
         [0054]     It is particularly advantageous when a cap is seated at a rear end of the position sensor facing away from the measuring end. This cap serves to close the rear end of the housing interior in relation to the surroundings. Connections of the connection element can also be guided through the cap in order to be able to supply the circuit of the position sensor with voltage with them and to be able to tap a measurement signal.  
         [0055]     In this respect, it is favorable when the cap is of a plastic material. It is advantageous, in particular, when the cap is at least partially transparent. A light emitting diode can then be arranged, for example, on the carrier and this indicates, for example, the operational state of the position sensor. This light emitting diode can be read out via a transparent cap.  
         [0056]     The production of the inventive position sensor may be simplified by the fact that the cap is pushed into the housing. The push-in length of a cap into the housing is, in particular, at least double the size of the inner diameter of the housing and is, for example, at least one third of the length of the housing so that the cap is held well in the housing. As a result, the cap, which is made of a plastic material, also effects a good insulation in relation to the housing and a high dielectric strength can be achieved.  
         [0057]     The cap advantageously has a stop, due to which the insertion path into the housing is limited. As a result, a secure hold of the cap on the housing is provided and, on the other hand, it is also possible to avoid filling compound from rising above a specific level when the cap is pushed in.  
         [0058]     It is particularly advantageous when the cap has an opening for the connection element. Connections such as contact pins of the connection element may be guided outwards through this opening. At the same time, the connection element may be aligned by this opening and, in particular, aligned in a centered manner and, again, the carrier-connection element combination may be aligned in order to ensure in this way, in particular, a quick and secure assembly. In particular, a strong shaking of the carrier-connection element combination in the molding compound poured in prior to its hardening, which would entail the risk of air pockets, may be avoided.  
         [0059]     It is advantageous when the opening is designed such that the carrier-connection element combination can be fixed in the housing transversely to the longitudinal direction thereof by means of this opening.  
         [0060]     It is particularly advantageous when the opening for the connection element has a smaller diameter than the housing. In this way, larger carriers can be pushed into the housing without the opening, which is required for a plug width, determining the diameter of the housing interior. As a result, the diameter of the connection element may be essentially decoupled from a width of the carrier-connection element combination which comes to rest in the housing interior.  
         [0061]     The connection element is favorably provided with a fixing means and the cap with a fixing means adapted thereto and the fixing means can engage in one another. As a result, the carrier-connection element combination and the cap may be oriented relative to one another and, in particular, oriented non-rotationally relative to one another. As a result, the assembly of the device can be made easier.  
         [0062]     In an advantageous variation of one embodiment, the cap is provided with an external thread. A clamping nut of a plug may be fixed on such an external thread and the plug may therefore be connected to the position sensor.  
         [0063]     The cap is favorably provided with a holder element for the force-locking fixing in the housing. This holder element may serve at the same time to prevent the molding compound from flowing out of the housing between an inner wall of the housing and a cap wall when the cap is pressed into it.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0064]     The following description serves to explain the invention in greater detail in conjunction with the drawings. These show:  
         [0065]      FIG. 1 a  longitudinal section through one embodiment of an inventive position sensor in a schematic illustration and  
         [0066]      FIG. 2 a  detailed view of the area A according to  FIG. 1 .  
     
    
     DETAILED DESCRIPTION  
       [0067]     One embodiment of an inventive position sensor, which is designated in  FIG. 1  as a whole as  10 , comprises a housing manufactured, in particular, from a metallic material. This housing  12  has a cylindrical housing interior  16  which is formed by an inner wall  14  of the housing and thus has essentially the same cross section transversely to a longitudinal axis  18  of the housing  12  over the entire length of the housing interior  16 . In a variation of one embodiment, the housing  12  is provided with an external thread  20  so that the inventive position sensor  10  can be fixed in a form-locking manner at its place of use, such as, for example, a machine tool.  
         [0068]     A carrier or support  22  is arranged in the housing interior  16  and an electrical circuit  24  is arranged on this carrier.  
         [0069]     The electrical circuit  24  comprises, in particular, a coil  26  which is provided with a pot core  28 . The position sensor  10  is then an inductive proximity sensor, wherein an inductive negative feedback occurs due to a metallic object approaching the coil  26  and the corresponding changes in the electrical parameters can be registered.  
         [0070]     The carrier  22  can, for example, be a printed circuit board, a ceramic substrate or also a flexible film, onto which the circuit components are embossed.  
         [0071]     The coil  26  is positioned in the housing interior  16  in the vicinity of a front end  30  of the housing  12  so that this front end  30  forms a measuring end of the position sensor  10 .  
         [0072]     The front end of the housing interior  16  is closed by a cup-shaped insert  32  so that a closure element for closing the housing interior  16  in relation to the surroundings is formed by this insert  32 .  
         [0073]     The insert  32  is manufactured, in particular, from a plastic material so that the cover plate  34  does not influence the inductive coupling of an object of measurement to the coil  26 .  
         [0074]     The insert  32  comprises a disk-shaped cover plate  34  which abuts on the front end  30  of the housing  12  at an end face  36  of this housing  12 . The diameter of the cover plate  34  is, in particular, somewhat smaller than the external diameter of the housing  12 .  
         [0075]     A cylindrical wall  38  is formed at right angles to the cover plate  34  and in one piece with it, wherein an external diameter of this wall  38  is slightly smaller than an internal diameter of the housing interior  16  so that the insert  32  can be pushed into the housing interior  16  from the front end  30 . In this respect, it is provided, in particular, for the height of the wall  38  above the cover plate  34  to be at least one third of the length of the housing  12  and, in particular, to be approximately half the length of the housing so that the wall  38  projects into the housing interior  16  over a larger area.  
         [0076]     As shown in greater detail in  FIG. 2 , the wall  38  is provided in the vicinity of the cover plate  34  with a circular sealing element  40  which is formed on it in one piece and is located between the insert and the housing inner wall  14  when the insert  32  is pushed in. In the embodiment shown, the sealing element is formed by two oppositely located sealing lips  42  and  44  which are triangular in cross section, namely in the shape of an essentially right-angled triangle. The right angle is formed, in the case of the sealing lip  42 , between the wall  38  and a side facing the cover plate and, in the case of the sealing lip  44 , between the wall  38  and the side facing away from the cover plate  34 . The sides of the sealing lips  42  and  44  arranged at an incline in relation to the wall  38  abut on one another between the corresponding, right-angled sides.  
         [0077]     As a result of the sealing element  40 , a liquid molding compound is, on the one hand, prevented from entering the surroundings from the housing interior  16  and a fluid from the surroundings is prevented from entering the housing interior  16 . In addition, the sealing element  40  contributes to the insert  32  being held on the housing  12  in a force-locking manner after its insertion into the housing interior  16 , whereby the production of the inventive position sensor  10  is made easier.  
         [0078]     At an end of the carrier  22  facing away from the end, at which the coil  26  is arranged, the carrier is rigidly connected to a connection element  46 , which is, in particular, a plug insert, such that the connection is mechanically secure and is flexible essentially in no direction. The connection element  46  comprises a contact carrier  48 , into which contact pins  50  are cast. Four contact pins are, for example, provided.  
         [0079]     Such a contact pin has an essentially straight part  52  which is oriented away from a rear end  54  of the housing  12  facing away from the front end  30  and is aligned, in particular, essentially parallel to the longitudinal axis  18 . Such a straight part  52  of a contact pin  50  is chamfered at an end section  56  in order to facilitate the introduction of a plug.  
         [0080]     A contact pin  50  is guided and, in particular, bent due to the contact carrier  48  such that it can be rigidly connected at a connection part  58  to the carrier  22 . The connection part  58  is soldered to the carrier  22  for this purpose.  
         [0081]     A supply current may be supplied to the circuit  24  via the electrical connection element and, in particular, via contact pins  50  and a sensor signal tapped for further processing.  
         [0082]     As a result of the soldering of the electrical connection element  46  via the contact pins  50  to the carrier  22 , a carrier-contact element combination  60  is formed which can be positioned as a unit during the production of the inventive position sensor  10 .  
         [0083]     A cap  62  is pushed into the housing interior  16  at the rear end  54  to close the housing  12  in relation to the surroundings. The cap  62  comprises for this purpose a first section  64  which is of an essentially cylindrical design and provided with a cylindrical opening  66 , in which the contact carrier  48  and the straight parts  52  of the contact pins  50  are arranged. The diameter of the opening  66  corresponds essentially to the diameter of the contact carrier  48 . A receiving space  70  for a plug for the connection to the contact pins  50  is formed in the opening  66  from the end face  68  of the contact carrier  48  facing away from the rear end  54  towards the surroundings. Furthermore, the first section  64  is provided with an external thread  72  so that a plug can be fixed on the cap  62 , for example, by means of a clamping nut.  
         [0084]     The cap  62  further comprises a second section  74  which is formed by a cylindrical wall  76  and is pushed into the housing interior  16 . The wall  76  is provided with a circular, projecting annular collar  78  formed on it in one piece; this annular collar  78  is arranged such that it is positioned somewhat beneath the rear end  54  of the housing  12  when the second section  74  is pushed in. The cap  62  may be held on the housing  12  in a force-locking manner as a result of the annular collar  78 . At the same time, care is taken that, when the external diameter of the wall  76  is somewhat smaller than the internal diameter of the housing interior  16 , the cap may be pushed into the housing interior  16  in a simple manner.  
         [0085]     The second section  74  is adapted to the housing diameter and the first section  64  to a plug diameter. Normally, a plug diameter is smaller than a housing diameter and therefore the first section  64  has a smaller diameter than the second section  74 .  
         [0086]     A third section  80  of the cap  62  provides the transition between the first section  64  and the second section  74 . For this purpose, this third section is designed in the shape of a truncated cone not only in relation to an external surface but also an internal surface. At the transition  82  between the third section  80  into the second section  74  a nose  84  in the shape of a circular ring is formed and the cap  62  can be abutted on an end face  86  at the rear end  54  by means of this nose when the cap  62  is pushed into the housing interior  16  with the second section  74 .  
         [0087]     A free space in the housing interior  16 , which is formed around the carrier  22  with the circuit arranged thereon, around the wall  38  of the insert  32  and the wall  76  of the cap  62 , is filled with a molding compound  88  solid after hardening, such as, in particular, a casting resin. As a result, the electrical circuit  24  is protected since no fluids can penetrate to the electronic components. On the other hand, as a result of the molding compound the insert  32  is held on the housing  12  and also the cap  62  is held on the housing  12 . This can be aided by the fact that the walls  38  and  76  are provided, in particular, facing the carrier  22  with recesses or the like for improving the coupling of the molding compound  88  (not shown in the drawings).  
         [0088]     During the production of the inventive position sensor  10 , the molding compound is poured in up to a specific level. During the insertion of the carrier-connection element combination  60  and/or during insertion of the cap  62  the molding compound which is still fluid rises up to a level defined by the amount of the liquid molding compound poured in. The filling amount is selected such that the molding compound  88  essentially covers the carrier  22  completely but leaves a space  90  free between the carrier  22  and the contact carrier  48 , in which the connection parts  58  of the contact pins  50  are arranged. As a result, a breakdown at the connection parts  58  of the contact pins can be avoided which could result if a molding compound sheathing were not completely continuous.  
         [0089]     One end  92  of the molding compound sheathing is then located essentially in the area of the third section  80  of the cap  62  or in the initial area of the opening  66  in the first section  64  of the cap  62 . Towards the cap  62 , the end  92  of the molding compound sheathing has a meniscus-like elevation  94 .  
         [0090]     During the insertion of a cap  62 , due to which the liquid molding compound is displaced in the direction of the rear end  54 , the provision of such a space  90  also serves to prevent the molding compound from hindering any abutment of the nose  84  on the end face  86  because too great an amount of liquid molding compound has erroneously been poured in. The space  90  thereby reduces the precision requirements in relation to the control of the molding compounds to be poured in.  
         [0091]     A shrinkage band  100  is arranged around the carrier  22  at the end of the carrier  22 , in particular, lying at least partially in the space  90  in order to increase the dielectric strength and thus increase the safety class.  
         [0092]     The cap  62  is manufactured from a plastic material and, in particular, from a transparent plastic material. As a result, a light emitting diode arranged at the end of the carrier  22 , which serves, for example, to monitor the functioning of the inventive position sensor  10 , may be observed from the surroundings.  
         [0093]     The cap  62  protrudes into the housing interior  16  with a length at least twice as great as the internal diameter thereof. As a result, an insulation is provided for in addition to the insulating property of the molding compound in order to improve the safety class of the position sensor in this way.  
         [0094]     The position sensor is manufactured in accordance with the invention as follows:  
         [0095]     The carrier  22  is rigidly connected to the connection element  46  to form the carrier-connection element combination  60 . With a front end (measuring end)  30  closed by means of the insert  32 , which is pushed into the housing interior  16 , the carrier-connection element combination  60  is inserted into the housing interior  16 , namely such that the pot core  28  of the coil  26  abuts on the surface of the cover plate facing the housing interior  16 . For this purpose, the housing  12  is, in particular, located on the cover plate  34  so that the longitudinal axis  18  of the housing  12  is oriented essentially parallel to the direction of gravity.  
         [0096]     A liquid molding compound and, in particular, a casting resin is then poured into the housing interior  16 , namely up to a specific level in order to be able to form the space  90  between the end  92  of the molding compound sheathing and the contact carrier  48 . For this purpose, the amount of the liquid molding compound poured in is advantageously controlled as a function of the volume of the housing interior  16  and the size of the carrier  22 .  
         [0097]     The molding compound can also penetrate the area between the insert  32  and the housing inner wall  14  and thus fix it (in addition) on the housing  12 . The same applies for the cap  62 .  
         [0098]     In this respect, it is favorable when the carrier  22  is leaned against a housing inner wall  14  during the filling in order to thus achieve a greater filling opening for filling the housing  12 .  
         [0099]     After filling with the liquid molding compound, the carrier-connection element combination  60  is aligned in relation to the longitudinal direction  18  prior to hardening of the molding compound such that the contact carrier  48  of the connection element  46  is essentially collinear to the longitudinal axis  18 . The second section  74  is then pushed into the molding compound, which is still fluid, in the housing interior  16  to connect the cap  62  to the housing  12 , wherein an alignment takes place between the opening  66  of the cap  62  and the contact carrier  48 .  
         [0100]     To facilitate this alignment and/or to improve the coupling between the cap  62  and the contact carrier  48  it may be provided for the contact carrier  48  to be provided with a notch  96  parallel to the longitudinal direction  18  and for the cap  62  to be provided with a bar  98  in the opening  66  which is adapted to the notch  96 . This bar  98  can then engage in the notch  96  in order to thus obtain a form-locking coupling between the cap  62  and the connection element  46 .  
         [0101]     After insertion of the cap  62  as far as abutment of the nose  84  on the end face  86 , the hardening of the molding compound  88  is awaited. The inventive position sensor  10  is then completely finished.  
         [0102]     In an alternative process, the carrier-connection element combination  60  is not, in contrast to the process described above, pushed into the housing interior  16  first but rather this interior, with an insert  32  inserted, is first filled with a liquid molding compound and then the carrier-connection element combination  60  is pushed from the rear end  54  into the housing interior  16  with the molding compound located therein, which is not yet hardened, until the pot core  28  abuts against the cover plate  34 . Subsequently, the cap  62  is then placed on the inserted carrier-connection element combination  60  as long as the molding compound is not yet hardened.  
         [0103]     Alternatively to the subsequent placement of the cap  62 , this can also be placed on the carrier-connection element combination  60  first of all prior to insertion of the carrier-connection element combination  60  into the filled housing  12  and the unit consisting of carrier-connection element combination  60  and positioned cap  62  is then inserted into the housing interior  16 .  
         [0104]     As a result of the filling with molding compound from the rear end  54  such that a homogeneous distribution of the molding compound is achieved and the space  92  is formed in a controlled manner, the centering of the carrier-connection element combination  60  by means of the cap  62  and the insulating, inserted second section  74  of the cap  62 , a high dielectric strength is achieved between the housing  12  and the circuit  24  and so the inventive position sensor  10  has a high safety class.