Connecting arrangement with a crimp connector and a wire fixed in place to the crimp connector

The connection refers to a connecting arrangement with a crimp connector (2) and a wire (3) fixed in place to the crimp connector. The crimp connector encompasses two clamping plates (4, 5) executed as one piece that, in a mounted state, clamp the wire (3) between them and while doing, so fix the wire (3) firmly in place with a force acting in longitudinal axial load direction (B). At least in the mounted state, the inner surfaces of the clamping plates face one another and are at least partially executed as level clamping surfaces (4a, 5a). In the mounted state, the clamping surfaces (4a, 5a) of the clamping plates (4, 5) make contact with one another, whereby an area of the wire section (3′) is pressed partially inside the one clamping plate and partially inside the other clamping plate (4, 5). At least one clamping plate (4, 5) has at least one back gripping surface (8) colliding with its clamping surface (4a, 5a) facing against the load direction (B) and extending transversally to the load direction (B), whereby the clamping surface (4a, 5a) of the other clamping plate (4, 5) extends beyond the back gripping surface (8) against the load direction (B).

TECHNICAL FIELD

The invention refers to a connecting arrangement that encompasses a crimp connector and a wire fixed in place or to be fixed in place to the crimp connector. A wire here is understood to be either a single filament or a single thread or, for example, a bundle of filaments developed like a strand. The crimp connector encompasses two clamping plates with a longitudinal wire section (e.g. a wire end) clamped between them.

BACKGROUND

In case of tensile-stressed wires such as spontaneously shortening wires from a shape memory alloy when a current is applied, care must be taken to ensure that the wire is not only electrically, but also firmly and mechanically connected to the crimp connector. For this purpose, often a form-fitting joint effective in the direction of the tensile load is aimed for in addition to the force-fitting joint accomplished by the clamping effect of the clamping plates. This can be accomplished by having a projection protruding from the interior of a clamping plate of one of the clamping plates of the crimp connector that contains the wire between them, and a recess opposite it in the interior of the other clamping plate. When the clamping plates are pressed together, the wire is pressed from the projection into the recess and is subject to considerable deformation. Therefore, this type of crimp connection cannot be used in delicate wires that would not resist the above-mentioned deformation.

Such a conductor connecting structure is known from DE 10 2013 217 000 A1, in which a conductor is enclosed between two plate-shaped holding parts. The first holding part has projections on one side facing the conductor, while the second holding part has through-holes that correspond to the position of the projections. If the conductor is clamped between the two holding parts, it is deformed by the projections in such a way that it is pushed into the through-holes and pressed firmly inside them.

DE 10 2004 036 829 A3 describes an electric bonding of a wire with two opposite plates, whereby a plate encompasses one bonding area and a recess corresponding to the bonding area and the wire is clamped between the bonding area and the recess.

JP 2013-207865 discloses a connecting clamp in which a wire is clamped and fixed in place between two clamping elements with tooth systems. Compression connectors, in which a conductor is clamped and fixed in place between two clamping plates are also described, for example, in published patents U.S. Pat. No. 6,855,409 B1, U.S. Pat. No. 4,034,152 A, U.S. Pat. No. 3,852,702 A and U.S. Pat. No. 3,523,173 A.

SUMMARY

Therefore, the task of the invention is to provide one crimp connector and one connecting arrangement encompassing a wire to ensure a secure mechanical and electrical connection that does not damage or destroy the wire.

This task is solved by a connecting arrangement according to the disclosure. According to it, the crimp connector encompasses two clamping plates formed as one piece that in mounted state clamp a longitudinal wire section, such as a wire end, in place between them, fixing it firmly in place against the load direction acting on the wire in longitudinal axial fashion. The inner surfaces facing one another—at least in the mounted state of the clamping plates—are at least developed partially as level clamping surfaces. The wire is made of a material that is harder than the material of the clamping plates. When they are mounted, the clamping plates make contact to one another with their clamping surfaces, whereby the size of the longitudinal wire section presses partially into one clamping surface and partially into the other one by displacing the clamping plate material. In this way, the longitudinal wire section is fixed in place to the crimp connector with a force-fitting joint effective in load direction.

Because the wire is embedded in the clamping plate material, wire and clamping plates make a large-surface contact and thus create a force-fitting joint having large tensile strength. Owing to the virtually complete enclosure of the entire wire size by the clamping plate material, the firmness of the force-fitting joint between clamping plates and wire is less sensitive towards tolerances such as the wire thickness or uneven surfaces of the clamping surfaces.

In addition to the wire's force-fitting fixation, a form-fitting joint in load direction is also provided and consists of the following: At least one clamping plate has at least one gripping surface that abuts the clamping surface and faces against the load direction that extends transversally to the load direction. The clamping surface of the other clamping plate extends in opposite direction of the load direction beyond the back gripping surface. A wire section extending away from the front surface of a clamping plate against the load direction is pressed by the clamping surface of the other clamping plate into a back gripping space extending beyond the back gripping surface in opposite direction of the load direction. Here, it is advantageous that to manufacture the form-fitting joint between crimp connector and wire, it only has to be deformed slightly in a direction extending transversally to its longitudinal extension. The distance around which the wire is deflected in the above-mentioned direction is roughly only one-half of the wire diameter because the wire held in clamped fashion is pressed half way into the clamping surface of one of the clamping plates and half way into the clamping surface of the other clamping surface. Contrary to conventional wire connectors with projections and recesses, there is therefore pronounced kink or no shaft-edged bending of the wire is necessary in the transition between a wire section running straight and one that is off-center that could impair its firmness or even lead to a break of the wire in its bent section.

DETAILED DESCRIPTION

FIG. 1shows a simplified embodiment of a connecting arrangement1. The connecting arrangement encompasses one crimp connector2and one wire3fixed in place to it. The crimp connector2has two clamping plates4,5executed as one piece, that in mounted state enclose a longitudinal wire section6between them. By doing this, they fix the wire3in place with a force acting on the wire in longitudinal axial load direction B. Thus, the wire3is firmly held in the crimp connector. The two clamping plates4,5are executed between them as one piece. The free end of one of the two clamping plates (indicated with reference sign4in the embodiments) changes into a base7for purposes of fixing to a part (not shown) and has a design that differs from the one of the clamping plate4(it can have fixation elements, for example, not shown). In mounted state according toFIG. 1and in the pre-mounted state according toFIG. 2, the inner surfaces of the clamping plates4,5are executed as level clamping surfaces4a,5a. In the embodiments shown in the illustrations, the inner surfaces4a,5aform as a whole the entire clamping surfaces4a,5a. However, it is also conceivable that only one part of the inner surfaces of the clamping plates4,5are executed as clamping surfaces4a,5a.

In mounted state, the clamping surfaces4a,5amake contact with the clamping plates4,5, thereby clamping the wire3. The wire is made of a material that is harder than the material of the clamping plates4,5. Consequently, in the mounted state (in which the clamping surfaces4a,5amake surface contact with one another), a wire section3′ area is pressed into the clamping plates4,5or the clamping surfaces4a,5athereby displacing the clamping plate material and as a result of this, gutter-shaped depressions14are formed. At the same time, the clamping plates4a,5aenclose the wire size completely, thus fixing the wire3form-fittingly in place between the clamping plates4,5with a tensile strength, i.e. with a force acting on it in longitudinal axial load direction.

In addition to the above-mentioned force-fitting joint, the wire3is held by a form-fitting joint effective in load direction B between the clamping plates4,5. To accomplish this, a back gripping surface8is provided on at least one clamping plate4a—in the embodiment shown inFIGS. 1 to 6, on the clamping plate5—bumping against the clamping surface5a, pointing against the load direction and extending transversally to the load direction B. Thus, the back gripping surface8encloses with the clamping surface5aan angle α of 60° to 120°, preferably of 90°. The clamping surface4aof the other clamping plate4extends against the load direction B beyond the back gripping surface8. As a result of this, in the mounted state, a wire section3″ extending away from the back gripping surface8of the clamping plate5in opposite direction G of the load direction B is pressed into a back gripping space9extending in opposite direction G of the back gripping surface8. In the wire section3″ clamped between the clamping plates4,5one-half of its size extends into one of the clamping plates4,5. Consequently, the wire section3″ extending beyond the back gripping surface8in opposite direction G is moved in perpendicular transversal direction Q around a distance opposite the wire section3′, which corresponds to half of the diameter D/2 of the wire (seeFIG. 4). According to this (only slight) lateral deflection of the wire section3′, the transition area15between the two wire sections3′ and3″ is only slightly bent and thus not executed with sharp edges.

As can be easily recognized whenFIG. 1is compared withFIG. 2, wire3must be inserted in such a way into the space10between the clamping plates4,5during mounting that it is positioned in the area of the back gripping surface8. Around this target position S, in which the wire3and the back gripping surface8intersect (seen in the top view on an outer surface13of the clamping plates4,5), the clamping plates4,5enclose an acute angle β in the pre-mounted state without ensuring an additional technical assembly effort. The angle β is chosen in such a way that the wire3is then located in the target position S when it abuts the clamping surfaces4a,5aof the clamping plates4,5. An adjustment to various wire thicknesses can take place by changing the angle β.

In the embodiments according toFIGS. 7 to 13, the back gripping surface8is part of the opening wall16of a slot opening17that opens up to the inner side4a,5aof the clamping plate4,5. The slot opening17extends preferably through the clamping plate4,5and thus ends also in the outer side13of the clamping plates4,5. Moreover, the slot opening17is preferably arranged completely within the clamping plates. This has the advantage that it makes not only one clamping area18extending away from the back gripping surface18in load direction B available, but also a clamping area18extending away in opposite direction G to fix the wire3in place. The depth19of the slot opening17is at least as large as the thickness20of the wire3. This ensures that a wire section3″ inserted through the slot opening17does not protrude above the outer side13of the clamping plate4,5and is therefore protectively arranged in the slot opening17.

In a preferred embodiment variant, the firmness of the connection between the wire3and the crimp connector2is increased by providing several slot openings17. Compared to a slot opening17bof the other clamping plate4,5, the slot opening17aof a clamping plate4,5is arranged in displaced way in load direction B. At the same time, the offset is measured preferably in such a way that there is a space between two successive slot openings17a,17bin load direction, i.e. that the slot openings do not overlap against one another. In this case, a clamping area18′ has been arranged between the opening slots17, in which a wire section3″ has been clamped as described above.