CLAMP
20240356245 · 2024-10-24
Inventors
Cpc classification
H01R9/26
ELECTRICITY
H01R43/20
ELECTRICITY
International classification
Abstract
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.
Claims
1. Terminal (10) for the connection of electrical conductors, comprising: a housing base body (12), a terminal body (12) positioned in said housing base body (12), and a housing cover (14) connectable to said housing base body (12); with said terminal body (20) comprising conductor insertion holes (22) and terminal screw holes (26), for terminal screws, transverse to said conductor insertion holes (22), characterized in that, pilot screws (28) function as terminal screws.
2. Terminal (10) according to claim 1, with guide shafts (32) in housing cover (14) aligning with said conductor insertion holes (22), with each guide shaft (32) possessing diameter reducers (4), with two pairs of ribs (42) and/or flat surfaces (44) opposite of each other along a circumferential line of the guide shaft (32) function as diameter reducers (40).
3. Terminal (10) according to claim 2, with terminal (10) possessing guide shafts (32) in housing cover (14) along a straight line, and correspondingly two guide shafts (32) are adjacent to each other in pairs, and where flat surfaces 44 functioning as diameter reducers 40 are located in an area of the smallest distance between two pairs of adjacent guide shafts (32).
4. Terminal (10) according to claim 3, where flat surfaces (44) are parallel to each other for all guide shafts (32).
5. Terminal (10) according to claim 3, with guide shafts (32) each ending in an insertion opening (34) on a surface of housing cover (14), and where imaginary minimal enveloping circles touch each other or overlap partially around an insertion opening (34).
6. Use of a terminal (10) according to claim 2, where firstly a pilot section (30) for each pilot screw (28) and secondly diameter reducers (40) for each guide shaft (32) are effective for radially securing a pilot screw (28) in both ways.
7. Use according to claim 6, where pilot screws (28) are firstly secured axially and secondly secured radially on both ends, without threads from the pilot screw (28) engaging with the threads of terminal screw holes (26).
8. Method for manufacturing a terminal (10) according to claim 1, wherein a fully assembled terminal body (20) is positioned in housing base body (12), said housing base body (12) then being closed by means of the housing cover (14), and said housing cover (14) being secured to said terminal body (20) in said housing base body (12), wherein, in a fully assembled terminal body (20), threaded shafts of said pilot screws (28), functioning as terminal screws, are partially screwed into terminal screw holes (26) of said terminal body (20), and wherein, after said housing base body (12) has been closed with housing cover (14), the heads of pilot screws (28) are located in said guide shafts (32) formed in said housing cover (14).
9. Method for manufacturing a terminal (10) according to claim 1, wherein a terminal body (20), without the pilot screws (28), functioning as terminal screws, is positioned in housing base body (12), said housing base body (12) then being closed by means of the housing cover (14), and said housing cover (14) being secured to said terminal body (20) in said housing base body (12), wherein said pilot screws (28) are then inserted through the guide shafts (32) formed in said housing cover (14), and at least partially screwed into the terminal screw holes (26) in said terminal body (20).
10. Method according to claim 8, wherein for the testing of operability of the threads of all terminal screw holes (26), the pilot screws (28) are fully screwed into said terminal screw holes (26) once and then unscrewed again, so that there remains only a little bit of contact.
11. Terminal (10) for the connection of electrical conductors, comprising: a housing base body (12), a terminal body (12) positioned in said housing base body (12), and a housing cover (14) connectable to said housing base body (12); with said terminal body (20) comprising conductor insertion holes (22) and terminal screw holes (26), for terminal screws, transverse to said conductor insertion holes (22), characterized in that, pilot screws (28) function as terminal screws, wherein said terminal (10) is manufactured according to the method of claim 8.
12. Method according to claim 9, wherein for the testing of operability of the threads of all terminal screw holes (26), the pilot screws (28) are fully screwed into said terminal screw holes (26) once and then unscrewed again, so that there remains only a little bit of contact.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In the figures:
[0018]
[0019]
[0020]
[0021]
[0022]
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
[0023] The presentations in
[0024] The illustration in
[0025] The illustration in
[0026] Housing base body 12 holds terminal body 20. Housing cover 14 secures terminal body 20 in housing base body 12 when placed in in [sic.-TR] housing base body 12. As an example, a brass bar, or a component made from an electrically conductive metal, functions as terminal body 20.
[0027] Terminal body 20 has, in a fundamentally known manner, a plurality of continuous (penetrating terminal body 20 transversely to its longitudinal axis), non-contacting, and non-overlapping conductor insertion holes 22. In the example shown, terminal 10 has seven such conductor insertion holes 22 for terminal body 20. The number of conductor insertion holes 22 is only provided as an example, and instead more or fewer conductor insertion holes 22 are also possible and conceivable, and as such, terminals 10 with more or fewer conductor insertion holes 22 are also considered to be included in the description presented here.
[0028] To maintain an overview of the attached Figures, only one of the conductor insertion holes 22 is shown at a time. Terminal 10 includes a plurality of characteristics, so for example, conductor insertion openings 24, terminal screw holes 26, etc., corresponding to the number of conductor insertion holes 22. To maintain an overview of the attached Figures, here as well these are only shown once in the Figures.
[0029] Housing base body 12 has a number of conductor insertion holes 22 corresponding to the number of conductor insertion openings 24, which align terminal body 20, positioned in housing base body 12, with the conductor insertion holes 22. Housing base body 12 has these conductor insertion openings 24 in both its large side surfaces (the illustrations in
[0030] Terminal body 12 has (likewise in a fundamentally known manner) a number of conductor insertion holes 22 corresponding to the number of terminal screw holes 26. The terminal screw holes 26 penetrate terminal body 20 (while not touching each other or overlapping each other) only one each to the conductor insertion holes 22. The axial direction of the terminal screw holes 26 is perpendicular to the axis of the conductor insertion holes 22, and likewise perpendicular to the longitudinal axis of terminal body 20. The terminal screw holes 26 extend into the material of terminal body 20 into the area of the underlying (in an axial direction) conductor insertion hole 22. The central longitudinal axis of each terminal screw hole 26 meets the respective conductor insertion hole 22 in the area of the apex of said conductor insertion hole 22: terminal screw hole 26 aligns with conductor insertion hold 22 (and correspondingly then also aligns with a guide shaft 32, respectively with a conductor insertion hole 22). Each terminal screw hole 26 has an inward-facing thread.
[0031] A terminal screw is provided in a fundamentally known manner for screwing into a terminal screw hole, using its inward-facing thread. Pilot screws 28 function as the terminal screws in the terminal presented here (
[0032] A pilot screw 28 comprises (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 screw 28 is 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 section 30 (
[0033] Terminal cover 12 has (likewise in a fundamentally known manner) a number of conductor insertion holes 22 (and terminal screw holes 26) corresponding to the number of cylindrical-jacket-shaped guide shafts 32 for each pilot screw 28. These guide shafts 32 align with terminal screw holes 26, as well as with conductor insertion holes 22, and end on the top surface of housing cover 14 at each of the insertion openings 34 (see
[0034] Depending on the type of manufacturing for terminal 10 (an initially fully assembled terminal body 20 or a subsequent assembly of terminal body 20), the insertion openings 34 also allow the subsequent assemble of terminal body 20, therefore, one without pilot screws already in the terminal body 20, positioned in housing base body 12, and another with the pilot screws 28 inserted into housing base body 12 already closed with housing cover 12. Finally, insertion openings 34 and the connected guide shafts 32 also allow for possible replacement of damaged pilot screws 28 or the like.
[0035] A diameter of guide shaft 32 is based on a diameter of the head of pilot screw 28. With terminal body 20 placed in housing base body 12 and housing cover 14 attached to housing base body 12, the pilot screws 28 can be inserted through guide shafts 32 into terminal 10 and brought into contact with terminal body 20. Pilot screws 28 can also be attached to terminal body 20 (thus, partially screwed into the inner thread of the terminal screw holes 26 therein) before terminal body 20 is placed in housing base body 12, so that terminal body 20, fully assembled, is then placed in housing base body 12, and said housing base body 12 is then closed with housing cover 14, and where guide shafts 32 come over the heads of the pilot screws 28 and incorporate them.
[0036] The pilot sections 30 of pilot screws 28 bring about the desired alignment of pilot screws 28, aligning them with the terminal screw holes 26. The diameter of the pilot section 30 is smaller than the diameter of the terminal screw holes 26 (smaller than the diameter of an imaginary cylinder inscribed in the terminal screw hole 26, the lateral surface of which just touches the tips of the threads). However, the diameter of pilot section 30 is also only slightly smaller than this diameter of terminal screw hole 26, so that for example, it is at least larger than half the size of this diameter of terminal screw hole 26. For example, an M5 screw for pilot section 30 has a diameter of 2.5 mm, while the core diameter of an M5 thread hole has a diameter of 4.2 mm.
[0037] Due to its diameter, pilot section 30 can be inserted into the area of a terminal screw hole 26 with a purely translational movement, until the connecting shaft of pilot screw 28 comes into contact by its threads with the inner threads of terminal screw hole 26. As long as the threads on the shaft of pilot screw 28 are not screwed into the inward-facing threads of terminal screw hole 26, pilot section 30 can be removed from the area of terminal screw hole 26 with a purely translational movement, and pilot screw 28 can still be moved in an axial direction. Said purely translational movement is a translational movement along the longitudinal axis of pilot screw 28, along the central longitudinal axis of the respective guide shaft 32, or long the central longitudinal axis of terminal screw hole 26.
[0038] If pilot section 30 of a pilot screw 28 is in the area of a terminal screw hole 26 and the thread on the shaft of pilot screw 28 has still not been screwed into the inner threads of terminal screw hole 26, the end of pilot screw 28, located in the area of terminal screw hole 26, can still be moved in terminal screw hole 26, in particular it can be moved radially to the longitudinal axis of pilot screw 28. However, this mobility is limited by the diameter of terminal screw hole 26. Mobility is only available until pilot section 30 abuts the inner surface of terminal screw hole 26.
[0039] Due to this limitation of mobility, a pilot screw secured at the same time in the axial direction and aligned with terminal screw hole 26, cannot leave the area of said terminal screw hole 26. Pilot screw 28 can therefore be screwed into terminal screw hole 26, in particular into its inner threads, at any time. This is independent of the orientation of terminal 10, when actuating pilot screw 28. Due to pilot section 30 being located in the area of terminal screw hole 26, the positioning of pilot screw 28, which is necessary and sufficient for direct contact of both threads (the threads on the pilot screw 28; the threads in terminal screw hole 26), remains in alignment with terminal screw hole 26, even when, for example, pilot screws 28 are oriented horizontally, due to a corresponding installation of terminal 10 (where the longitudinal axes of pilot screws 28 are horizontal or at least substantially horizontal).
[0040] For the illustration in
[0041] In other words, the adjustment of pilot screws 28 made in terminal 10 as proposed here can be expressed as follows: The central longitudinal axes of each terminal screw hole 26, and the respective guide shafts 32, are at least in parallel, and normally coincide or at least substantially coincide. For a pilot screw 28, whose pilot section 30 is inserted into a terminal screw hole 26, this will ensure that even the longitudinal axis of this pilot screw 28 will be in parallel or at least substantially parallel with the central longitudinal axis of terminal screw hole 26, so that pilot screw 28 can be directly screwed into the threads of terminal screw hole 26.
[0042] Pilot screw 28 must also be secured in the axial direction, so that pilot section 30 of pilot screw 28 remains in the area of the respective terminal screw hole 26 when pilot screw 28 is aligned with said terminal screw hole 26. This is achieved in the terminal 10 proposed herein by means of an appropriate design of the guide shafts 32. For this purpose, guide shafts 32 have a means for the axial securing of pilot screw 28, or are designed as a means for the axial securing of pilot screw 28.
[0043] In the embodiment shown, guide shafts 32 have a means for diameter reduction (diameter reducer 40, diameter reducing means 40) as a means for axially securing a pilot screw 28. For example, two ribs 42, opposite each other along the circumferential line of a guide shaft 32, function as a diameter reducer 40 (
[0044] The illustration in
[0045] The, or each, rib 42 protrude(s) in the shape of a nose from the inner surface of guide shaft 32: it points radially from the inner surface of guide shaft 32 towards the center of guide shaft 32. The, or each, flat surface 44 is/are in an area in which guide shaft 32 is not limited by a lateral surface section with constant radius r1, but by a flat surface. The surface of a guide shaft 32 with exactly such a flat surface 44 results in the area of this flat surface 44 as the area of a circle with radius r1/diameter d2 (normal radius r1/normal diameter d2) of guide shaft 32 minus the area of a circle segment, where the circle segment results from this circle and a circle chord corresponding to the position of flat surface 44.
[0046] An imaginary circle 46 inscribed in a guide shaft 32, transversely to the longitudinal axis of guide shaft 32, the circle line of which touches ribs 42 and flat surfaces 44, has a smaller diameter d2 than guide shaft 32 without these diameter reducers 40 (diameter d1). Ribs 42 and flat surfaces 44 therefore reduce the effective diameter of guide shaft 32. This justifies their designation as diameter reducers 40. This designation includes the two options described here for reducing the effective diameter (rib(s) 42 and/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.
[0047] For manufacturing reasons, the, or each, flat surface 44 can be longer in the axial direction of the respective guide shaft 32 than the, or each, rib 42 in the same guide shaft 32. Diameter reducers 40 each work together for axial securing. The area of a guide shaft 32 in which it always has (along its axial extension) all diameter reducing means, i.e. all diameter reducers 40 (so, for example, all ribs 42 and all flat surfaces 44), is referred to as the securing section. In the embodiment, the securing section is a cylindrical portion of each guide shaft 32, which extends from one end of each rib 42 included in guide shaft 32 to the other end thereof in the axial direction of said guide shaft 32. Flat surfaces 44 also extend in this area, therefore in the area of the securing section. However, they may extend (in the axial direction of guide shaft 32) beyond the securing section on one or both sides.
[0048] To further explain the axial securing of a pilot screw 28 provided in the terminal 10 proposed 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 shaft 32 (each guide shaft 32), then the diameter d2 of a circle 46 inscribed in guide shaft 32 in the area of the diameter reducer 40 as described above (diameter d2 in the securing section), and finally the diameter d3 of an exactly cylindrical screw head of a pilot screw 28. For these and the associated radii r1 (d1=2r1), r2 (d2=2r2), r3 (d3=2r3), the following applies: d2<d1, d2<d3; d1>d2; d1>d3; d2<d3 (r2<r1, r2<r3; r1>r2; r1>d3; r2<r3).
[0049] A pilot screw can therefore be freely moved axially in guide shaft 32 outside of the securing section, because diameter d3 of the screw head is at least smaller than the diameter d1 of guide shaft 32 in 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.
[0050] In particular, diameter reducers 40 are an integral part of housing cover 14 and are in any case made of the same material as housing cover 14. Housing cover 14 is a plastic part. Correspondingly, guide shaft 32 in housing cover 14 (each guide shaft 32) is made out of plastic. The plastic is elastically deformable within the scope of its material properties. Therefore, diameter reducers 40, and/or the section of guide shaft 32 adjoining each diameter reducer 40, are elastically deformable. Because of this elastic deformation, a screw head located in the securing section in guide shaft 32 is clamped (clamped through force-fitting) by diameter reducers 40, or at least some of diameter reducers 40. The screw; namely the pilot screw: 28 in the terminal 10 in question, is thereby axially secured in guide shaft 32.
[0051] The location of the securing section along each guide shaft 32 (the securing section extends in the axial direction of guide shaft 32 in each said guide shaft 32) is chosen so that the clamping of the screw head is effective whenever pilot section 30, at the opposite end of the pilot screw 28 from the screw head, is in the area of the respective terminal screw hole 26. Because of the clamping of the screw head, the pilot screw 28 is then secured in the axial direction and the pilot section 30 in terminal screw hole 26 secure said pilot screw 28 in the radial direction. Pilot screw 28 is then positioned in line over terminal screw hole 26 in the manner described above, and is also secured here at least against falling out unintentionally or against unwanted tilting.
[0052] The means for the axial securing of pilot screw 28, especially the diameter reducers 40, for one, and the pilot sections 30, for another, are together both effective for guiding each pilot screw: The means for axial fixation not only secures pilot screw 28 in the axial direction, but also secures the end of pilot screw 28 with the head in the radial direction as well (radially to the longitudinal axis of pilot screw 28). In the case of a pilot screw 28 secured in the axial direction through the axial securing means, its pilot section 30 is located in the area of terminal screw hole 26, without the threads of pilot screw 28 necessarily being engaged with the threads of terminal screw hole 26. This causes a radial securing (radially to the longitudinal axis of pilot screw 28) of the other end of pilot screw 28, in particular the end with pilot section 30. By radially securing it in both ways, this optimally ensures a matching alignment of the pilot screw 28 with terminal screw hole 26, and with its inward-facing threads, as mentioned above already.
[0053] The embodiment shown with four diameter reducers 40, 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 reducers 40, the screw head may not be sufficiently clamped in the securing section.
[0054] In particular, the desired axial securing of the screw; in this case pilot screw 28, would then no longer be possible. With four diameter reducers 40, each located in a quadrant of guide shaft 32, this clamping is ensured, even with screw heads that are not exactly round.
[0055] The illustrations in
[0056] The flat surfaces 44, as diameter reducers 40, in addition to participating in the axial securing of pilot screw 28 and radially securing pilot screw 28 on one side (the head side), have another advantage, which is explained in reference to the illustration in
[0057] As can be seen (
[0058] A particularly small distance is provided when the guide shafts 32 in housing cover 14 are designed with such distances that the imaginary minimal enveloping circles 48 touch each other or partially overlap around an insertion opening 34 of said guide shafts 32. The illustration in
[0059] In the embodiment of terminal 10 shown, flat surfaces 44 of all guide shafts 32 are parallel to one another. This makes possible a small or minimal distance between all guide shafts 32. This also makes it possible for terminal 10 to be small in size along the straight line along which guide shafts 32 are arranged and formed in housing cover 14. Finally, this also makes possible a correspondingly shorter terminal body 20, and a shorter terminal body 20 leads to a savings in materials.
[0060] 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.
[0061] 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 screws 28 as terminal screws and/or in the way in which the pilot screws 28 are secured axially and/or radially.
LIST OF REFERENCE SYMBOLS
[0062] 10 Terminal [0063] 12 Housing base body [0064] 14 Housing cover [0065] 20 Terminal body [0066] 22 Conductor insertion hole [0067] 24 Conductor insertion opening [0068] 26 Terminal screw hole [0069] 28 Pilot screw [0070] 30 Pilot section [0071] 32 Guide shaft [0072] 34 Insertion opening [0073] 40 Diameter reducer [0074] 42 Rib [0075] 44 Flat surface [0076] 46 Circle [0077] 48 Enveloping circle