Screwless clamping device for electrical conductors

Abstract

Screwless clamping device for electrical conductors, in particular lightning protection or earthing conductors with the same or different cross-sectional area, consisting of at least two opposing spring legs (1; 2, 5; 6) made of electrically conductive material, which form a spring leg pair (3; 4) and which have a shape for receiving and contacting a section of the respective electrical conductor (30), and with a connecting section (7; 8) between the spring legs (5; 6; 1; 2), wherein a first clamping part with at least two spring legs (1; 2) and a second clamping part with at least two spring legs (5; 6) is provided, wherein the respective connecting sections (7; 8) are arranged connectably between the spring legs (1; 2, 5; 6), lying back to back, characterized by the fact that the first and second terminal part consists of at least two spaced-apart, opposing pairs of spring legs (3; 4), wherein the respective connecting section (7; 8) additionally extends over a space between the pairs of spring legs (3; 4), and in the case of electrical conductors (30) with an oval or circular cross-section, the spring legs (1; 2, 5; 6) each have a shape approximating a V, thereby creating contact zones with high surface pressure at contact points or contact surfaces.

Description

[0001] The invention relates to a screwless clamping device for electrical conductors, in particular lightning protection or earthing conductors with the same or different cross-sectional area, consisting of at least two opposing spring legs made of electrically conductive material, which form a pair of spring legs and which have a shape for receiving and contacting a section of the respective electrical conductor, as well as with a connecting section between the spring legs according to the preamble of claim 1.

[0002] A screwless holder for electrical conductors is already known from DE 299 06 078 U1. The screwless holder is intended for use in particular for conductors with a circular cross-section, in particular lightning rods. It comprises a support element against which the inserted conductor rests, and spring-loaded claws extending from the support element. Their free ends are directed toward the support element and form a support for the inserted conductor.

[0003] In order to achieve an axially immovable or axially displaceable arrangement of the conductor in the holder, four claws are arranged crosswise to one another, defining two intersecting insertion or pressing areas for a conductor between them, wherein one of the insertion or pressing areas is matched to a conductor diameter such that the inserted conductor is held axially immovably by the claws. The other insertion or pressing area, on the other hand, is matched to the diameter of the conductor such that the inserted conductor can be held axially displaceably. Preferably, each claw has a flat web protruding approximately orthogonally from the support part and a flat holding web angled in a V-shape towards the support part. It is also preferred that two claws are arranged on opposite edges of the support part, wherein an insertion gap to the conductor is formed between the adjacent claws.The insertion gap between the claws, particularly between the flat webs or claws protruding from the support part, is slightly larger than the diameter of the conductor to be inserted. Each claw has an edge at the end facing the inserted conductor, with one corner of the edge being spaced from the conductor support surface of the support part by a distance that is smaller than the conductor diameter. The other corner of the edge is spaced from the conductor support surface of the support part by a distance that is selected to be equal to or greater than the conductor diameter.

[0004] In one embodiment, the support part including the claws is formed as a single piece from a stamped and bent sheet metal part. It is also possible to create a protective cap that can be attached to the holder and the inserted conductor, covering the claws. This protective cap is pot-shaped and can be snapped onto the support part or other claws. The protective cap can also be designed as a marking carrier.

[0005] While the previously known solution allows for the holding and contacting of a conductor with a round cross-section, there is a risk that the contact areas between the claws and the conductor may not meet the requirements for exposure to lightning impulse currents. This disadvantage is particularly evident when the electrical conductor is concrete reinforcing steel, which, due to its typical surface structure, does not have a smooth, electrically optimized surface.

[0006] In the snap-in holder for a conductor wire according to DE 198 17 061 C1, housing parts form a receptacle for inserting a conductor wire. Furthermore, spring legs are provided which form claws pointing towards the receptacle. A lower housing area is provided with an electrically conductive connection means, e.g. a screw. To improve the current-carrying capacity from the conductor wire to the connection means, an electrically conductive contact piece is designed to be elastically flexible in the direction of the lower housing area. The additional contact piece, which conforms to the conductor wire and is connected to the additional connecting means, improves the ability of the snap-in holder to conduct even larger currents from the conductor wire to the connection means. However, the design of a housing part with an inserted additional, elastically flexible contact piece is technologically complex and leads to higher costs.The holder for the conductor wire, which forms a quasi-closed trough, can become dirty when such snap holders are used for the purpose of contacting reinforcements, resulting in a significantly impaired electrical contact and associated malfunctions.

[0007] Various studies and practical applications of known snap-on terminals have shown that connecting strip or round materials in reinforcements is problematic due to the limited space available. While existing terminals with screw contacts can form quite strong and well-conducting contacts, the use of one or more screws and their operation requires additional assembly effort. Installation is further complicated by the need to simultaneously handle the grounding conductor, terminals, and assembly tools. Conventional snap-on terminals, on the other hand, are either too complex to manufacture or unable to safely conduct the surge currents that occur under load.

[0008] DE 102 30 072 A1 concerns a clamp for fastening cables with current-conducting supports.

[0009] DE 19 27 764 A relates to a fastening clamp for use in the attachment of electrical cables.

[0010] DE 200 14 028 U1 concerns a holder for a lightning conductor wire.

[0011] DE 20 2012 102 394 U1 relates to a fastening element for fastening an electrical conductor and / or a cable to a profiled support.

[0012] DE 34 36 119 A1 relates to a device for contacting printed circuit boards and sheet metal parts.

[0013] Based on the above, it is therefore an object of the invention to provide a further developed screwless clamping device for electrical conductors, in particular lightning protection or earthing conductors with the same or different cross-sectional area, wherein the clamping device consists of few parts and can preferably be manufactured as a cost-effective stamped and bent part. In the simplest case, the clamping device should be made of just two parts, which can, for example, securely contact a round conductor on the one hand and a flat conductor on the other, and electrically connect these conductors. Furthermore, it is an object of the invention to design the clamping device in such a way that a wide variety of applications can be covered by a diverse combination of clamping devices, all of which rely on the spring clamping principle, without the need to keep a large number of parts in stock.

[0014] The object of the invention is achieved by a screwless clamping device according to the combination of features of claim 1, wherein the subclaims comprise at least expedient embodiments and further developments.

[0015] It is therefore assumed that this is a screwless clamping device for electrical conductors. This can, in particular, be lightning protection or earthing conductors with the same or different cross-sectional areas, e.g., a circular cross-sectional area or a rectangular cross-sectional area, i.e., a flat conductor.

[0016] The screwless clamping device can also be used as a direct connecting part in the area of ​​lightning protection and earthing or shielding, as it serves to contact, for example, reinforcement mats with each other, whereby an additional connecting wire or an additional connecting band can be dispensed with.

[0017] The screwless clamping device consists of at least two opposing spring legs made of an electrically conductive material, with the opposing spring legs forming a pair of spring legs. Furthermore, the spring legs are shaped to receive and contact a section of the respective electrical conductor. Furthermore, a connecting section is provided between the spring legs.

[0018] According to the invention, a first clamp part with at least two spring legs and a second clamp part with at least two spring legs are provided, wherein the respective connecting sections between the spring legs are preferably arranged so as to be connectable back to back.

[0019] The connection of the spring legs or pairs of spring legs back-to-back can be force-fit, form-fit and / or material-fit.

[0020] In the present invention, the first and / or second clamp part consists of at least two spaced-apart, opposite pairs of spring legs, with the respective connecting portion extending additionally across a space between the pairs of spring legs. This means that two spaced-apart pairs of spring legs are present on a common longitudinal axis, with the connecting portion extending across the longitudinal axis.

[0021] In the present invention, the shape of the spring legs is circular arc-like or in the shape of an approximate V.

[0022] At the end of the spring legs opposite the respective connecting section, these have an angled or bent portion, which on the one hand increases stability and on the other hand improves the snapping onto a conductor.

[0023] A stabilizing bar is formed between the spaced-apart pairs of spring legs in the area of ​​the respective free end of the spring leg. This stabilizing bar connects the adjacent spring legs located on one side. This ensures sufficient rigidity of the clamping device and the necessary surface pressure relative to the inserted electrical conductor.

[0024] The spacing of the spring legs of the leg pairs and the shape for accommodating the respective conductor are adapted to the cross-section of the conductor to be used. Back-to-back terminal components with the same spacing of the spring legs or with different spacing can be combined. With such a back-to-back assembly, for example, a conductor with a smaller cross-section can be securely electrically connected and contacted with a conductor with a larger cross-section using the clamping device.

[0025] Due to the selectable position of the terminal parts when arranged back-to-back, both conductors running parallel to one another and conductors running at an angle to one another can be contacted.

[0026] In electrical conductors with an oval or circular cross-section, particularly those conductors that correspond to conventional reinforcing steel with a structured surface, the spring legs each have a shape that approximates to a V, whereby contact zones with high surface pressure are created at the contact points or contact surfaces, so that the desired lightning impulse current carrying capacity is achieved under all circumstances. According to a comparative example of the invention, the first and / or second terminal part consists of at least two spaced-apart spring legs lying in one plane, with a spring tongue extending into the spacing space. The spring tongue and the spring legs merge into a common connecting section, which is designed as an angled portion, whereby a back-to-back connection of terminal parts can be realized via the angled portion.

[0027] In this comparative example, in a preferred implementation, the spring tongue extends over a first length section in the plane of the bend, over a second length section in the direction of the free end of the spring legs and over a third length section in the direction of the plane of the spring legs.

[0028] According to the comparison example, a flat conductor can then be inserted and held in a clamped manner between the spring tongue and the spring leg.

[0029] In a further development of the comparative example of the invention, the third length section merges into an insertion bevel for the flat conductor.

[0030] In one embodiment of the comparative example of the invention, the free ends of the spring legs can have a bend in order to partially encompass a received conductor and to fix it against being pushed out.

[0031] In a preferred embodiment, the width of the spring legs is selected to be equal to or greater than the width of the spring tongue.

[0032] The invention further provides for a combination of terminal parts according to the first embodiment of the invention with terminal parts according to the comparative example of the invention. This allows conductors with a round or oval cross-section to be electrically connected and contacted with flat conductors.

[0033] In a further development of the invention, the first and / or second terminal part according to the first embodiment of the invention can be completed with a lid-like cover after being snapped onto the respective electrical conductor.

[0034] The cover is designed in such a way that it encompasses the free ends of the pairs of spring legs.

[0035] In a further development, the cover has two opposite legs which dip into the space between the pairs of spring legs and encompass the inserted conductor with one leg section.

[0036] The invention furthermore consists in the use of a screwless clamping device with the features according to an embodiment and a comparative example of the invention for contacting strip and / or round reinforcement materials in the field of lightning protection or earthing, wherein the strip or round reinforcement materials are cast in Seton or similar materials.

[0037] The invention will be explained in more detail below using exemplary embodiments and with the aid of figures.

[0038] Here we show: Fig. 1a and Fig. 1b various perspective views of a clamp part with two pairs of spring legs lying on a longitudinal axis, wherein each pair of spring legs consists of two spring legs and wherein a stabilizing web is provided between the spaced-apart pairs of spring legs in the region of the respective free end of the respective spring leg; Fig. 2a and Fig. 2b various perspective views of the comparative example of the clamping device with a clamping part, which consists of two spaced spring legs lying in one plane, wherein a spring tongue dips into the space and the spring tongue and the spring legs merge into a common connecting section, which is designed as an angled portion, so that a back-to-back assembly or connection of several such clamping parts or with one clamping part according to the Fig. 1a and Fig. 1b can be done; Fig. 3a and Fig. 3b Illustrations of a back-to-back assembly of two clamp parts according to the Fig. 2a and Fig. 2b without ( Fig. 3a) and with ( Fig. 3b) flat conductors; Fig. 4a and Fig. 4b shows a back-to-back assembly of a terminal part with pairs of spring legs and a terminal part with spaced spring legs and spring tongue, rotated by 90° relative to each other, for receiving both a flat conductor and a round conductor according to Fig. 4b; Fig. 4c and Fig. 4d a representation similar to that of Fig. 4a, but with parallel arrangement of the terminal parts to accommodate parallel round conductors and flat conductors ( Fig. 4d); Fig. 5a and Fig. 5b Illustrations of the combination and back-to-back assembly of two terminal parts each with pairs of spring legs and different shapes for accommodating round conductors of different cross-sections, as shown in Fig. 5b; Fig. 6a and Fig. 6b a representation of a back-to-back design of terminal parts with formations in the spring leg pairs for receiving parallel round conductors with the same cross-section, as in the Fig. 6b is shown, and Fig. 7 a perspective view of a terminal part with pairs of spring legs and accommodated round conductor as well as a lid-like cover to ensure the locking of the round conductor in the terminal part.

[0039] In the illustration of the first embodiment of the invention according to the Fig. 1a and Fig. 1b shows a first clamp part with two spring legs 1; 2, wherein the spring legs 1; 2 form a first pair of spring legs 3.

[0040] A second pair of spring legs 4 extends from the spring legs 5; 6, which are spaced apart from the spring legs 1; 2. Between the spring legs 1; 2 and the spring legs 5; 6, connecting sections 7 and 8 are provided. Two spring legs 8, as shown in the Fig. 1a and Fig. 1b terminal parts can be used as shown in the Fig. 6a, are connected back-to-back, using the connecting sections 7; 8 in this regard.

[0041] The connecting sections 7; 8 extend in a central area, as shown in the illustration according to the Fig. 1a and Fig. 1b, also via the distance between the pairs of spring legs 3; 4, so that a stable terminal part design is obtained.

[0042] The shape of the spring legs 5; 6 and 1; 2 is as shown in the Fig. 1a and Fig. 1b, adapted to a round conductor and has the shape of a V, which is particularly noticeable in the frontal perspective view according to Fig. 1b is recognizable.

[0043] At the ends opposite the connecting section 7; 8, the spring legs are each provided with an angled portion in the form of a bend or offset 10.

[0044] A stabilizing web 11 is formed between the spaced-apart pairs of spring legs 3; 4 in the region of the respective free end of the respective spring leg 1; 2 or 5; 6.

[0045] The stabilizing webs 11 connect the adjacent spring legs 1; 5 and 2; 6 located on one side.

[0046] The spacing of the spring legs 1; 2 or 5; 6 of the leg pairs 3; 4 and the shape for accommodating the respective conductor is adapted to the cross-section of the respective conductor. Back-to-back terminal components with the same spacing of the spring legs, but also with different spacing, can be combined, as shown in the Fig. 5a, Fig. 5b or 6a and Fig. 6b. The back-to-back connection can be made by means of a material fit, a form fit, or a force fit, whereby the position of the clamp parts, as shown in the Fig. 4a to 4d, can be chosen arbitrarily relative to each other.

[0047] In the comparison example of a terminal part, as shown in the Fig. 2a and Fig. 2b in various views, this consists of at least two spaced-apart spring legs 20; 21 lying in one plane, wherein a spring tongue 22 extends into the space between the spring legs 20; 21, wherein the spring tongue 22 and the spring legs 20; 21 merge into a common connecting section 23, which is designed as an angled portion. Via this angled portion, a back-to-back connection of clamp parts can be achieved, either according to the comparative example according to the Fig. 2a and Fig. 2b with each other or a combination of one terminal part each, e.g. according to the Fig. 1a with such a terminal part according to the Fig. 2b. These corresponding combination options are described in the Fig. 3a and Fig. 3b and Fig. 4a to 4d illustrated.

[0048] The spring tongue 22 of the terminal part according to the Fig. 2a and Fig. 2b extends over a first longitudinal section 24 in the plane of the bend 23, over a second longitudinal section 25 in the direction of the free end of the spring legs 20; 21 and over a third longitudinal section 26 in the direction of the plane of the spring legs 20; 21.

[0049] A flat conductor can be inserted and held clamped between the spring tongue 22 and the spring legs 20; 21, as is the case with the Fig. 3b, Fig. 4b and Fig. 4d shows an example.

[0050] The third length section 26 is shown in the illustrations according to the Fig. 2a and Fig. 2b into an insertion bevel 27 for the flat conductor.

[0051] The free ends of the spring legs 20; 21 also have a bend or angled portion 28 to partially encompass and fix a conductor. This is evident from the illustrations, particularly according to the Fig. 3b, Fig. 4b and Fig. 4d recognizable.

[0052] The width of the spring legs 20; 21 can be selected to be equal to or greater than the width of the spring tongue 22. Preferably, the respective width of the spring legs 20; 21 is greater than the width of the spring tongue 22. Thus, the spring tongue 22 can be optimized by selecting its width and, moreover, by designing the thickness of the corresponding material with regard to the desired spring properties and the bendability of the tongue, whereby the spring legs 20; 21 can be realized to be less flexible and have the largest possible contact surface in relation to the electrical conductor (see the illustrations according to the Fig. 3b, Fig. 4b and Fig. 4d).

[0053] As already indicated, the terminal parts can be configured according to the basic configuration Fig. 1a; Fig. 1b and Fig. 2a; Fig. 2b can be combined with each other, but also with each other, so that the application possibilities can be expanded according to the illustrations in the Fig. 3a to 6b.

[0054] As in the Fig. 7, a terminal part can be assembled according to the illustrations in Fig. 1a and Fig. 1b after snapping on the respective electrical conductor 30, in Fig. 7 designed as a round conductor, can be completed with a lid-like cover 31.

[0055] In this regard, the cover 31 encompasses the free ends of the spring leg pairs 3; 4, particularly in the area of ​​the bends or offsets 10.

[0056] In one embodiment, the cover 31 has two opposing legs 32 which extend into the space between the pairs of spring legs 3; 4 and at least partially encompass the inserted conductor 30 with one leg section.

Claims

[1] Screwless clamping device for electrical conductors, in particular lightning protection or earthing conductors with the same or different cross-sectional area, consisting of at least two opposite spring legs (1; 2, 5; 6) made of electrically conductive material, which form a pair of spring legs (3; 4) and which have a shape for receiving and contacting a section of the respective electrical conductor (30), as well as with a connecting section (7; 8) between the spring legs (5; 6; 1; 2), wherein a first clamping part with at least two spring legs (1; 2) and a second clamping part with at least two spring legs (5; 6) is provided, wherein the respective connecting sections (7; 8) are arranged so as to be connectable between the spring legs (1; 2, 5; 6), lying back to back, characterized by , that the first and second terminal part consists of at least two spaced-apart, respectively opposite pairs of spring legs (3; 4), wherein the respective connecting section (7; 8) extends additionally over a spacing space between the pairs of spring legs (3; 4), and in the case of electrical conductors (30) with an oval or circular cross-section, the spring legs (1; 2, 5; 6) each have a shape of an approximate V, whereby contact zones with high surface pressure are created at contact points or contact surfaces. [2] Screwless clamping device according to claim 1 characterized by that at the end opposite the respective connecting section (7; 8) the spring legs (1; 2, 5; 6) have an angular portion or offset portion (10). [3] Screwless clamping device according to claim 1, characterized bythat a stabilizing web (11) is provided between the pairs of spring legs (3; 4) in question in the region of the respective free end of the respective spring leg (1; 5, 2; 6). [4] Screwless clamping device according to claim 3, characterized by that the stabilizing web (11) connects the adjacent spring legs (1; 5, 2; 6) located on one side. [5] Screwless clamping device according to one of the preceding claims, characterized by that the distance between the spring legs (1; 2, 5; 6) of the leg pairs (3; 4) and the shape for receiving the respective electrical conductor (30) is adapted to the cross-section of the respective conductor (30), wherein back-to-back terminal parts with the same distance between the spring legs (1; 2, 5; 6), but also with different distances between them, can be combined. [6] Screwless clamping device according to one of the preceding claims, characterized bythat the back-to-back connection is made by means of a material fit, a form fit or a force fit, whereby the position of the clamp parts relative to each other can be selected. [7] Screwless clamping device according to one of claims 1 to 6, characterized by that the first and / or second terminal part can be completed with a lid-like cover (31) after being snapped onto the respective electrical conductor (30). [8] Screwless clamping device according to claim 7, characterized by that the cover (31) encompasses the free ends of the spring leg pairs (3; 4). [9] Screwless clamping device according to claim 8, characterized by that the cover (31) has two opposite legs (32) which dip into the space between the pairs of spring legs (3; 4) and encompass the inserted conductor (30) with one leg section.

Images