CLAMP

The invention relates to a clamp (10), more particularly PEN clamp, for connection of electrical conductors, and is characterized by the use of pilot screws (28) as the clamping screws and/or in the way the pilot screws (28) are axially and/or radially secured.

SUMMARY OF THE INVENTION

One purpose of the innovation presented here is to provide a terminal with inputs according to the prior art, but that can be used with particular ease and safety.

This is solved according to the invention by means of a terminal with characteristics according to claim1.

The terminal, specifically arranged for the connection of a conductor, in particular of PEN conductors, comprises an at least two-part housing with a housing base body and a housing cover, as well as a terminal body positioned in the housing base body. Optionally, the terminal is a terminal with a housing base body, a terminal body positioned in the housing base body, and a housing cover that closes the housing base body and secures the terminal body in the housing base body: For the connection of electrical conductors, namely for the introduction of the ends of the electrical conductors, the terminal body has conductor insertion holes and, across from said conductor insertion holes, terminal screw holes for terminal screws. The special feature of the terminal is that pilot screws function as the terminal screws, and that the terminal has said pilot screws that function as terminal screws.

Pilot screws are known in the art and, like conventional screws (threaded screws) have a screw head and a threaded shaft [attached] to the screw head. The special feature of pilot screws is that they have a thread-free pilot section at the end of the threaded shaft. The diameter of the pilot section is smaller than the diameter of the threaded shaft. Therefore, a pilot screw has at least two different shaft sections, namely one on the screw shaft, connecting to the screw head, with a thread, and a pilot section connecting thereto with a comparatively smaller diameter.

In the prior art, the terminal screw hole in the terminal's terminal body has an inward-facing thread. Terminal screws are selected or manufactured so that the threading (outward facing thread) of the threaded shaft matches the inward facing thread of the terminal screw holes. Thus a pilot screw can be screwed into a terminal screw hole. Each terminal screw hole is open to a conductor insertion hole. By screwing a pilot screw into a terminal screw hole, the pilot section eventually reaches the area of the conductor insertion hole and, like a comparable conventional screw; is effectively for affixing a conductor end that has been inserted there.

Because the pilot section of a pilot screw has a smaller diameter than the threaded shaft of a comparable screw without a pilot section, even conductor ends with a smaller diameter can be securely clamped with a pilot screw: Geometrically, this can be explained as follows: The conductor insertion hole is circular. The free end of the pilot section is a line, namely a line on the plane of the circle. By screwing the pilot screw into the terminal screw hole, this imaginary line eventually comes into contact with this imaginary circle (the pilot section abuts against the inner surface of the conductor insertion hole). The imaginary line is then a circle chord. A circular segment remains between the circular chord and the circle. The smaller the circular segment (the surface of the circular segment), the shorter the circular chord is. The circle chord is shorter for a pilot screw (because of the tap) than for a comparable screw without a pilot section. The smaller the circular segment is, the better conductor ends can be clamped, even when they have a smaller diameter. This facilitates/improves the use or usability of conventional terminals.

Because the pilot sections of pilot screws are thread-free, they can be inserted into a terminal screw hole, and to the area of its internal threading with just a translational movement. Pilot screws can also reach into terminal screw holes using their pilot sections without the pilot screw being already screwed into the inner facing threads there. The pilot section is therefore effective for adjusting the threaded shaft of the pilot screw into alignment with the thread of the terminal screw hole, and with this kind of aligned adjustment, the pilot screw can be screwed directly into the threads of the terminal screw hole without risks such as tilting. This also facilitates/improves the use or usability of conventional terminals.

An arrangement for securing electrical connector terminals using screws is known from EP 2 215 693 A1. However, in this document normal threaded screws are used, in particular shaft screws, and therefore not pilot screws. An earth bar device is known from DE 20 2014 105 219 U. In this case as well, the screws intended for use as terminal screws are normal threaded screws and not pilot screws.

The dependent claims relate to advantageous embodiments of the terminals in question. The dependent relationships used in the claims show the further development of the subject matter from the claim in question through the characteristics of the respective dependent claim. These are not to be understood as a waiver of achievement of an independent, objective protection of the characteristic or combination of characteristics of a dependent claim. Furthermore, with regard to the interpretation of the claims and the description, it must be assumed when a characteristic is specified in more detail in a dependent claim that such a limitation is not present in the respective preceding claims or in a more general embodiment of the apparatus in question. Any reference in the description to aspects of dependent claims is therefore to be read expressly as a description of optional characteristics, even when no special reference is made.

It is advantageously stipulated that with such a terminal, in particular a terminal that has guide shafts in the housing cover that are aligned with the conductor insertion holes, each guide shaft has a means for reducing the effective diameter, at least in sections (diameter reducer; diameter reducer means). These are effective for axially securing (especially for axially securing and radially securing) a pilot screw in the guide shaft and thereby for axially securing the pilot screw in relation to the terminal body and the respective terminal screw hole. Due to this axial securing, the pilot section of a pilot screw, which is guided into the area of a terminal screw hole, remains in this area, and the adjustment of the terminal screw caused by the pilot section is ensured to be in alignment with the terminal screw hole and its inner-facing thread.

Two pairs of ribs and/or flat surfaces opposite of each other along a circumferential line of the guide shaft are possible as diameter reducers.

When producing a terminal of the type proposed here, the terminal body can be fully assembled with pilot screws and placed in the housing base body in its assembled state (an initially fully equipped terminal body). The housing base body is then closed using the housing cover and the housing cover secures the terminal body to the housing base body. The heads of the pilot screws are then located in the guide shafts formed in the housing cover. The assembly of the terminal body with pilot screws takes place by screwing their threaded shafts into the terminal screw holes at least a little bit, or even only a little bit (for example just one thread turn). The user of a terminal produced in this manner finds all conductor insertion hole open in a terminal body assembled with pilot screws. Conductor ends to be connected can be inserted directly and clamped by tightening the pilot screws. It is not necessary to unscrew the pilot screws beforehand in order to free up the conductor insertion holes. As an alternative to such a terminal body pre-assembled with pilot screws, the terminal body can also come without pilot screws positioned in the housing base body (subsequent assembly of the terminal body). The housing base body will also then be closed using the housing cover and the housing cover secures the terminal body to the housing base body. Afterwards, the pilot screws are introduced through the guide shafts formed in the housing cover, and screwed into the terminal screw holes in the terminal body at least a little bit, or even only a little bit. In this case as well, the user finds a terminal produced in this way with all conductor insertion holes open.

Both manufacturing variants provide the producer of such a terminal the advantage that the movement of all threads can be checked before delivery of each terminal (in particular they can be checked automatically using appropriate screwing tools) and the producer can ensure the proper operation of the terminal and each clamping site included in the terminal. With such a test step, when using a terminal body already assembled with pilot screws before positioning it in the housing base body, the pilot screws are fully screwed once into the terminal screw holes, and then unscrewed again, so far that there is only the little bit of contact mentioned above between the two threads, for example, where there is only contact of one thread along the circumference. The threads are tested by screwing in and unscrewing, and the test is only considered successful if the screwing in and then unscrewing are done smoothly. With a terminal body first placed in the housing base body with no pilot screws, and the housing base body closed by means of the housing cover, the pilot screws are inserted through the guide shafts and screwed completely into the threaded holes and then unscrewed again so far that there is only the little bit of contact mentioned above between the two threads, for example, where there is only contact of one thread along the circumference. In this case as well, the threads are tested by being screwed in and then unscrewed, and the test is only considered successful if the screwing in and then unscrewing are done smoothly.

The claims submitted with the application are a proposed wording notwithstanding the achievement of further protection. Since the characteristics of the dependent claims in particular can form separate and independent inventions in view of the prior art as of the priority date, the applicant reserves the right to make these characteristics or combinations of characteristics previously only disclosed in the description and/or drawings the subject of independent claims or division declarations. These can also include independent inventions that have a design that is independent of the subject matter of the claims referred to in each case.

An embodiment of the invention is explained below in more detail, with reference to the drawings. Corresponding items and elements are provided with the same reference numbers in all figures.

The embodiment is not to be understood as a limitation of the invention. Rather, within the scope of this disclosure, additions and modifications are also possible, in particular those that can, for example, be found by a person skilled in the art through combination or variation of individual characteristics in connection with those described in the general or specific descriptions, as well as characteristics or process steps included in the claims and/or the drawings, with a view of solving the problem, and leading to a new object through combinable characteristics.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

The presentations inFIGS.1,2and3show various views of an embodiment of terminal10proposed here, intended in particular for use as a PEN-terminal. Terminal10comprises a housing of at least two parts, with a housing base body12and a housing cover14. Housing base body12can be closed by means of housing cover14, and when terminal10is in a condition such that it is ready to use, housing base body is closed by means of housing cover14.

The illustration inFIG.1shows terminal10in an isometric view, where in the chosen perspective two side surfaces and the top side of terminal10can be seen. The illustration inFIG.2shows terminal10in a side view, looking at one of the large side surfaces of terminal10. The illustration inFIG.3shows terminal10from above.

The illustration inFIG.4shows a cross-section through terminal10along the line IV-IV shown inFIG.3.

Housing base body12holds terminal body20. Housing cover14secures terminal body20in housing base body12when placed in in [sic.-TR] housing base body12. As an example, a brass bar, or a component made from an electrically conductive metal, functions as terminal body20.

Terminal body20has, in a fundamentally known manner, a plurality of continuous (penetrating terminal body20transversely to its longitudinal axis), non-contacting, and non-overlapping conductor insertion holes22. In the example shown, terminal10has seven such conductor insertion holes22for terminal body20. The number of conductor insertion holes22is only provided as an example, and instead more or fewer conductor insertion holes22are also possible and conceivable, and as such, terminals10with more or fewer conductor insertion holes22are also considered to be included in the description presented here.

To maintain an overview of the attached Figures, only one of the conductor insertion holes22is shown at a time. Terminal10includes a plurality of characteristics, so for example, conductor insertion openings24, terminal screw holes26, etc., corresponding to the number of conductor insertion holes22. To maintain an overview of the attached Figures, here as well these are only shown once in the Figures.

Housing base body12has a number of conductor insertion holes22corresponding to the number of conductor insertion openings24, which align terminal body20, positioned in housing base body12, with the conductor insertion holes22. Housing base body12has these conductor insertion openings24in both its large side surfaces (the illustrations inFIGS.1and2show the same large side surfaces and only one large side surface each).

Terminal body12has (likewise in a fundamentally known manner) a number of conductor insertion holes22corresponding to the number of terminal screw holes26. The terminal screw holes26penetrate terminal body20(while not touching each other or overlapping each other) only one each to the conductor insertion holes22. The axial direction of the terminal screw holes26is perpendicular to the axis of the conductor insertion holes22, and likewise perpendicular to the longitudinal axis of terminal body20. The terminal screw holes26extend into the material of terminal body20into the area of the underlying (in an axial direction) conductor insertion hole22. The central longitudinal axis of each terminal screw hole26meets the respective conductor insertion hole22in the area of the apex of said conductor insertion hole22: terminal screw hole26aligns with conductor insertion hold22(and correspondingly then also aligns with a guide shaft32, respectively with a conductor insertion hole22). Each terminal screw hole26has an inward-facing thread.

A terminal screw is provided in a fundamentally known manner for screwing into a terminal screw hole, using its inward-facing thread. Pilot screws28function as the terminal screws in the terminal presented here (FIGS.3,4,7and8); terminal10proposed here has pilot screws28as terminal screws. Pilot screws28can also be seen in the illustration inFIG.3as part of the top view of terminal10shown there.

A pilot screw28comprises (like any threaded screw) a screw head (the head) with an actuating contour, and a screw shaft (the shaft) connecting thereto, with an outward-facing thread. The special feature of a pilot screw28is that concentrically on the shaft with the outward-facing thread there is an additional cylindrical section connected, with a diameter that is smaller in comparison to the shaft. This additional cylindrical section is the pilot section30(FIG.4) of pilot screw28.

Terminal cover12has (likewise in a fundamentally known manner) a number of conductor insertion holes22(and terminal screw holes26) corresponding to the number of cylindrical-jacket-shaped guide shafts32for each pilot screw28. These guide shafts32align with terminal screw holes26, as well as with conductor insertion holes22, and end on the top surface of housing cover14at each of the insertion openings34(seeFIG.1: the reference line runs to the edge of insertion opening34). A central longitudinal axis of a guide shaft32meets perpendicularly with a central longitudinal axis of the conductor insertion hole22(meeting or substantially meeting and perpendicularly or at least substantially perpendicularly: both due to unavoidable manufacturing tolerances). Because of the position of these central longitudinal axes in relation to one another, it is justified, at least in an extended sense, to speak of guide shafts32that are concentric with conductor insertion holes22. Insertion opening34allows the insertion of a tool, such as a screwdriver, for the known actuation of a single pilot screw28

Depending on the type of manufacturing for terminal10(an initially fully assembled terminal body20or a subsequent assembly of terminal body20), the insertion openings34also allow the subsequent assemble of terminal body20, therefore, one without pilot screws already in the terminal body20, positioned in housing base body12, and another with the pilot screws28inserted into housing base body12already closed with housing cover12. Finally, insertion openings34and the connected guide shafts32also allow for possible replacement of damaged pilot screws28or the like.

A diameter of guide shaft32is based on a diameter of the head of pilot screw28. With terminal body20placed in housing base body12and housing cover14attached to housing base body12, the pilot screws28can be inserted through guide shafts32into terminal10and brought into contact with terminal body20. Pilot screws28can also be attached to terminal body20(thus, partially screwed into the inner thread of the terminal screw holes26therein) before terminal body20is placed in housing base body12, so that terminal body20, fully assembled, is then placed in housing base body12, and said housing base body12is then closed with housing cover14, and where guide shafts32come over the heads of the pilot screws28and incorporate them.

The pilot sections30of pilot screws28bring about the desired alignment of pilot screws28, aligning them with the terminal screw holes26. The diameter of the pilot section30is smaller than the diameter of the terminal screw holes26(smaller than the diameter of an imaginary cylinder inscribed in the terminal screw hole26, the lateral surface of which just touches the tips of the threads). However, the diameter of pilot section30is also only slightly smaller than this diameter of terminal screw hole26, so that for example, it is at least larger than half the size of this diameter of terminal screw hole26. For example, an M5 screw for pilot section30has a diameter of 2.5 mm, while the core diameter of an M5 thread hole has a diameter of 4.2 mm.

Due to its diameter, pilot section30can be inserted into the area of a terminal screw hole26with a purely translational movement, until the connecting shaft of pilot screw28comes into contact by its threads with the inner threads of terminal screw hole26. As long as the threads on the shaft of pilot screw28are not screwed into the inward-facing threads of terminal screw hole26, pilot section30can be removed from the area of terminal screw hole26with a purely translational movement, and pilot screw28can still be moved in an axial direction. Said purely translational movement is a translational movement along the longitudinal axis of pilot screw28, along the central longitudinal axis of the respective guide shaft32, or long the central longitudinal axis of terminal screw hole26.

If pilot section30of a pilot screw28is in the area of a terminal screw hole26and the thread on the shaft of pilot screw28has still not been screwed into the inner threads of terminal screw hole26, the end of pilot screw28, located in the area of terminal screw hole26, can still be moved in terminal screw hole26, in particular it can be moved radially to the longitudinal axis of pilot screw28. However, this mobility is limited by the diameter of terminal screw hole26. Mobility is only available until pilot section30abuts the inner surface of terminal screw hole26.

Due to this limitation of mobility, a pilot screw secured at the same time in the axial direction and aligned with terminal screw hole26, cannot leave the area of said terminal screw hole26. Pilot screw28can therefore be screwed into terminal screw hole26, in particular into its inner threads, at any time. This is independent of the orientation of terminal10, when actuating pilot screw28. Due to pilot section30being located in the area of terminal screw hole26, the positioning of pilot screw28, which is necessary and sufficient for direct contact of both threads (the threads on the pilot screw28; the threads in terminal screw hole26), remains in alignment with terminal screw hole26, even when, for example, pilot screws28are oriented horizontally, due to a corresponding installation of terminal10(where the longitudinal axes of pilot screws28are horizontal or at least substantially horizontal).

For the illustration inFIG.4, the pilot screws28are oriented vertically (the longitudinal axes of the pilot screws28are vertical) and pilot screws28are located with their externally threaded shaft above terminal screw holes26. This position over terminal screw holes26is a position in alignment with said terminal screw holes26. However, such a position of the pilot screws28over terminal screw holes26is not always the case. With an installment of terminal10(e.g. in a switch cabinet or the like) in another orientation and with a corresponding different orientation of the pilot screws28, said screws will be located next to or even under the terminal screw holes26. Since pilot section30is at the end of pilot screw28, even with this kind of installation condition, where pilot section30is located in the area of terminal screw hole26, this ensures an alignment where pilot screw28is sufficiently aligned with terminal screw hole26. A sufficient alignment is an alignment were the threads of pilot screw28can be screwed directly into the inward-facing thread of terminal screw hole26.

In other words, the adjustment of pilot screws28made in terminal10as proposed here can be expressed as follows: The central longitudinal axes of each terminal screw hole26, and the respective guide shafts32, are at least in parallel, and normally coincide or at least substantially coincide. For a pilot screw28, whose pilot section30is inserted into a terminal screw hole26, this will ensure that even the longitudinal axis of this pilot screw28will be in parallel or at least substantially parallel with the central longitudinal axis of terminal screw hole26, so that pilot screw28can be directly screwed into the threads of terminal screw hole26.

Pilot screw28must also be secured in the axial direction, so that pilot section30of pilot screw28remains in the area of the respective terminal screw hole26when pilot screw28is aligned with said terminal screw hole26. This is achieved in the terminal10proposed herein by means of an appropriate design of the guide shafts32. For this purpose, guide shafts32have a means for the axial securing of pilot screw28, or are designed as a means for the axial securing of pilot screw28.

In the embodiment shown, guide shafts32have a means for diameter reduction (diameter reducer40, diameter reducing means40) as a means for axially securing a pilot screw28. For example, two ribs42, opposite each other along the circumferential line of a guide shaft32, function as a diameter reducer40(FIGS.4,5,6and7) and/or two flat surfaces44(FIGS.1,5,6and7) opposite each another along the circumferential line of guide shafts32in the surface of said guide shafts32. Ribs42and/or flat surfaces44extend in an axial direction from a respective guide shaft32. Imaginary lines between the ribs42on the one hand and the flat surfaces44on the other hand (the line between the flat surfaces44is perpendicular to said flat surfaces44) are perpendicular to each other, or substantially perpendicular.

The illustration inFIG.5shows a schematically simplified diagram of the basic geometric conditions inside a guide shaft32with diameter reducers40. InFIG.5, two ribs42opposite each other and two flat surfaces44opposite each other are shown as a diameter reducer40. These are regularly distributed along the circumferential line of guide shaft32. Guide shaft32is not round, at least due to flat surfaces44. Nevertheless, a diameter d1 (normal diameter) of guide shaft32is mentioned here and below: This results from the radius r1of the lateral surface sections, which remain adjacent to the flat areas, with a constant radius (d1=2×r1).

The, or each, rib42protrude(s) in the shape of a nose from the inner surface of guide shaft32: it points radially from the inner surface of guide shaft32towards the center of guide shaft32. The, or each, flat surface44is/are in an area in which guide shaft32is not limited by a lateral surface section with constant radius r1, but by a flat surface. The surface of a guide shaft32with exactly such a flat surface44results in the area of this flat surface44as the area of a circle with radius r1/diameter d2 (normal radius r1/normal diameter d2) of guide shaft32minus the area of a circle segment, where the circle segment results from this circle and a circle chord corresponding to the position of flat surface44.

An imaginary circle46inscribed in a guide shaft32, transversely to the longitudinal axis of guide shaft32, the circle line of which touches ribs42and flat surfaces44, has a smaller diameter d2 than guide shaft32without these diameter reducers40(diameter d1). Ribs42and flat surfaces44therefore reduce the effective diameter of guide shaft32. This justifies their designation as diameter reducers40. This designation includes the two options described here for reducing the effective diameter (rib(s)42and/or flat surface(s)44) and, apart from the specific embodiment shown in the drawings, all these options can be considered in any number and arrangement.

For manufacturing reasons, the, or each, flat surface44can be longer in the axial direction of the respective guide shaft32than the, or each, rib42in the same guide shaft32. Diameter reducers40each work together for axial securing. The area of a guide shaft32in which it always has (along its axial extension) all diameter reducing means, i.e. all diameter reducers40(so, for example, all ribs42and all flat surfaces44), is referred to as the securing section. In the embodiment, the securing section is a cylindrical portion of each guide shaft32, which extends from one end of each rib42included in guide shaft32to the other end thereof in the axial direction of said guide shaft32. Flat surfaces44also extend in this area, therefore in the area of the securing section. However, they may extend (in the axial direction of guide shaft32) beyond the securing section on one or both sides.

To further explain the axial securing of a pilot screw28provided in the terminal10proposed here, an additional diameter d3 is considered, in addition to the two diameters d1 and d2 already mentioned. The diameters are: Firstly, the diameter d1 of a guide shaft32(each guide shaft32), then the diameter d2 of a circle46inscribed in guide shaft32in the area of the diameter reducer40as described above (diameter d2 in the securing section), and finally the diameter d3 of an exactly cylindrical screw head of a pilot screw28. For these and the associated radii r1(d1=2×r1), r2(d2=2×r2), r3(d3=2×r3), the following applies: d2<d1, d2<d3; d1>d2; d1>d3; d2<d3 (r2<r1, r2<r3; r1>r2; r1>d3; r2<r3).

A pilot screw can therefore be freely moved axially in guide shaft32outside of the securing section, because diameter d3 of the screw head is at least smaller than the diameter d1 of guide shaft32in this area. As soon as the screw head enters the area of the securing section, the smaller diameter d2 comes into effect here. This is smaller than the diameter d3 of the screw head.

In particular, diameter reducers40are an integral part of housing cover14and are in any case made of the same material as housing cover14. Housing cover14is a plastic part. Correspondingly, guide shaft32in housing cover14(each guide shaft32) is made out of plastic. The plastic is elastically deformable within the scope of its material properties. Therefore, diameter reducers40, and/or the section of guide shaft32adjoining each diameter reducer40, are elastically deformable. Because of this elastic deformation, a screw head located in the securing section in guide shaft32is clamped (clamped through force-fitting) by diameter reducers40, or at least some of diameter reducers40. The screw; namely the pilot screw:28in the terminal10in question, is thereby axially secured in guide shaft32.

The location of the securing section along each guide shaft32(the securing section extends in the axial direction of guide shaft32in each said guide shaft32) is chosen so that the clamping of the screw head is effective whenever pilot section30, at the opposite end of the pilot screw28from the screw head, is in the area of the respective terminal screw hole26. Because of the clamping of the screw head, the pilot screw28is then secured in the axial direction and the pilot section30in terminal screw hole26secure said pilot screw28in the radial direction. Pilot screw28is then positioned in line over terminal screw hole26in the manner described above, and is also secured here at least against falling out unintentionally or against unwanted tilting.

The means for the axial securing of pilot screw28, especially the diameter reducers40, for one, and the pilot sections30, for another, are together both effective for guiding each pilot screw: The means for axial fixation not only secures pilot screw28in the axial direction, but also secures the end of pilot screw28with the head in the radial direction as well (radially to the longitudinal axis of pilot screw28). In the case of a pilot screw28secured in the axial direction through the axial securing means, its pilot section30is located in the area of terminal screw hole26, without the threads of pilot screw28necessarily being engaged with the threads of terminal screw hole26. This causes a radial securing (radially to the longitudinal axis of pilot screw28) of the other end of pilot screw28, in particular the end with pilot section30. By radially securing it in both ways, this optimally ensures a matching alignment of the pilot screw28with terminal screw hole26, and with its inward-facing threads, as mentioned above already.

The embodiment shown with four diameter reducers40, each opposite one another in pairs, has proven to be particularly advantageous. In particular, it must be taken into account that screw heads, and therefore the heads of the pilot screws chosen for use here, are not always exactly round. This depends above all on the method of manufacture. In the case of screw heads that do not have a sufficiently precise cylindrical shape, if there are fewer than four diameter reducers40, the screw head may not be sufficiently clamped in the securing section.

In particular, the desired axial securing of the screw; in this case pilot screw28, would then no longer be possible. With four diameter reducers40, each located in a quadrant of guide shaft32, this clamping is ensured, even with screw heads that are not exactly round.

The illustrations inFIGS.6and7show a portion of housing cover14. The illustration inFIG.6shows a portion of housing cover14in a top view: The illustration inFIG.7shows an isometric view of the housing cover part. In the illustrations inFIGS.6and7, the diameter reducers40, especially the ribs42and flat surfaces44, which act as said diameter reducers40in the embodiment shown, are particularly easy to see. In the illustration inFIG.7, there is a pilot screw28, the head of which can be seen, in one of the guide shafts32shown. The head of pilot screw28is located in guide shaft32at the level of all diameter reducers40. The screw head will therefore be clamped by means of the diameter reducers40(held by means of diameter reducers40through force fitting). Pilot screw28is axially secured in this position and is also radially secured on its end with the screw head.

The flat surfaces44, as diameter reducers40, in addition to participating in the axial securing of pilot screw28and radially securing pilot screw28on one side (the head side), have another advantage, which is explained in reference to the illustration inFIG.8. The illustration inFIG.8shows terminal10from above as inFIG.3. Two of the pilot screws28are hidden in favor of an illustration of an imaginary enveloping circle48(the illustration inFIG.3shows all the pilot screws28, in particular their screw heads, which can be seen in the guide shafts32). The enveloping circle28encloses the insertion opening34of each guide shaft32(enveloping circle28corresponds to the circle with radius r1in the illustration inFIG.5).

As can be seen (FIGS.1,3and8) the guide shafts32are arranged along a straight line in housing cover14. Each two guide shafts32are neighboring each other in pairs. Flat surfaces44, which function as diameter reducers40, are each located in an area of the smallest distance between two pairs of adjacent guide shafts. This makes possible a very small distance between two pairs of adjacent guide shafts32, while at the same time maintaining a separation of said guide shafts32(the inner surface of each guide shaft32is continuous along the entire circumferential line). The distance from one flat surface44to the opposite flat surface44of the same guide shaft32is smaller than the diameter of the enveloping circle48surrounding insertion opening34of said guide shaft32. Along the straight line, along which the guide shafts32are formed and arranged in housing cover14, said guide shafts32are therefore narrower than enveloping circle48(see alsoFIG.5: r2<r1). Therefore, even if guide shafts32are separated, smaller distances are possible than with completely round guide shafts32.

A particularly small distance is provided when the guide shafts32in housing cover14are designed with such distances that the imaginary minimal enveloping circles48touch each other or partially overlap around an insertion opening34of said guide shafts32. The illustration inFIG.7shows the situation where enveloping circles48at least touch one another. Enveloping circles48are minimal if they have the smallest possible diameter with which said enveloping circle48still enclose insertion opening34.

In the embodiment of terminal10shown, flat surfaces44of all guide shafts32are parallel to one another. This makes possible a small or minimal distance between all guide shafts32. This also makes it possible for terminal10to be small in size along the straight line along which guide shafts32are arranged and formed in housing cover14. Finally, this also makes possible a correspondingly shorter terminal body20, and a shorter terminal body20leads to a savings in materials.

Although the invention has been illustrated and described in detail by the example embodiment, is not limited by the examples disclosed and other variations may be derived therefrom by persons skilled in the art without departing from the protective scope of the invention.

Individual key aspects of the description submitted here can be briefly summarized as follows: A terminal is specified, which functions in particular as a PEN terminal (for connecting PEN conductors; PEN=protective earth neutral) for connecting electrical conductors. Its special feature lies in the use of pilot screws28as terminal screws and/or in the way in which the pilot screws28are secured axially and/or radially.

LIST OF REFERENCE SYMBOLS