EP0490066B1 - Pliers for crimping wire end ferrules - Google Patents

Description

The invention relates to a crimping tool for crimping wire end sleeves with two jaws mounted in a pivot bearing, which are pivotable about the pivot bearing in particular via a drive having two hand levers, with a spring jaw being provided on each jaw, the drive on one end of the jaws attacks and with the other ends of the jaws a press jaw is connected, which has a single, universally intended to cover a cross-sectional area pressing point. To equip ready-to-connect conductor ends of electrical cables, it is known to push a wire end sleeve onto the stripped wire end, which encompasses the wires of the wire, and to press this wire end sleeve so that it has a firm, immovable fit. The electrical conductor is then connected via a screw connection at the connection point, which presses on the pressed ferrule. The wire end sleeves have an annular cross section in the unpressed state. After crimping, a trapezoidal cross-sectional shape should be created according to DIN, in order to achieve a particularly intimate connection of the wire end ferrule with the conductor.

A crimping tool of the type described at the outset, which can be used universally for a cross-sectional area between 0.5 and 4.0 mm², is constructed according to the scissor principle, ie one jaw forms a part with a handle and the two parts can be pivoted with one another via an axle pin connected. The two press jaws are articulated on the jaws and guided against each other and form a pressing point, the axis of which lies in the main plane of extension of the crimping pliers, with which the end face or head end can be pressed. The flexibility of bridging the path differences is achieved here in that the jaws have an open-edged recess in the center of the flexible pivot bearing in the direction of the handles, in the area of which the journal is arranged. The jaws thus form quasi spring jaws or alternative springs. The frontal arrangement of the pressing point is also advantageously provided here. The disadvantage is that the one-piece design of the handles and the jaws allows only a simple lever transmission of the drive, so that the crimping pliers require relatively high actuation forces. There is also a risk of material fatigue due to the described resilient or resilient design of the jaws and their load. The spring forces provided by the jaws also depend to a large extent on compliance with tight tolerances in the cross-sections of the jaws. A change in material thickness or even a deviation in the prescribed hardness changes the spring properties of the pliers, so that no reproducible results can be expected with appropriate tolerances. If a wire end sleeve with a larger cross-section than the maximum cross-section provided is inserted and pressed between the press jaws, there is a risk that the overall resilient jaws will be plastically deformed so that the crimping tool can no longer be used properly.

Another crimping pliers designed as universal pliers has two pressing jaws which have a single pressing point, that is to say a single nest, for deforming conductors of different strengths. This universal pliers can be used to crimp conductors that have a cross-section between 0.5 and 4.0 mm². When a conductor with a small cross section, for example 0.5 mm², is pressed, the press jaws close largely or completely at the point in time at which the drive has traveled its maximum distance, that is to say, for example, the hand levers are maximally compressed are. When pressing larger cross-sections, for example 4.0 mm², the press point remains relatively open, ie the press jaws must end their path earlier, including the conductor material, while conversely the drive covers an identical path in all cases. In order to compensate for these path differences, a flexible swivel bearing is also provided on the jaws of the crimping pliers. One jaw is firmly connected to the handle, that is, it is formed in one piece with it. A toggle lever drive, which can be actuated via the other handle, acts as the drive on the other jaw. The two jaws are pivoted about an axle, for example in the manner of rocker arms. The jaw driven by the toggle lever drive is only pivotably supported with a cylindrical bore on the axle journal, while the other jaw engages around the axle journal with an elongated hole which is arranged parallel to the direction of movement of the press jaws during pressing in the jaw. On this jaw, which forms a part with the handle, a horseshoe-shaped alternative spring is pivotally suspended in a pivot pin, the other end of which engages the pivot pin of the two jaws. When pressing cross sections of different thicknesses, the alternative spring allows one jaw to dodge relative to the other jaw, and thus one press jaw to dodge relative to the other press jaw, although the identical path is covered on the jaws by the drive. The compressible cross-sectional area is limited to cross-sections between 0.5 and 4.0 mm². The advantage of this crimping pliers is the arrangement of the pressing jaws, which allow the conductor end and the wire end sleeve to be inserted at the pressing point transversely to the main extension plane of the crimping pliers, so that a taper of the pressed wire end sleeve is avoided. The relative arrangement of the press point is disadvantageous insofar as, for example, difficulties can arise in narrow control cabinets. The horseshoe-shaped alternative spring, arranged in a double arrangement and in association with the one jaw is considerably stressed when pressing thicker cross sections, so that there is a risk that material fatigue occurs here. The press jaws are arranged on the jaws, but cannot be pivoted relative to them, so that the press jaws take over the scissor movement of the jaws even during the closing process. This scissor movement leads to the formation of a flap on one side, ie the pressed cross-section has no symmetrical shape.

Another known universal crimping tool has a jaw driven by a toggle lever drive. The other jaw is divided towards the handle, here a plastic block is arranged in a cuboid housing, which can be pressed together via an end plate on the handle, so that the required path differences on the press jaws can be achieved in this way. The two jaws are swivel-mounted on a common journal without elongated holes. The pivotability of the split jaw is limited between stops, so that there are limits to the compression of the plastic block. The press jaws are articulated here on the jaws and guided against one another, whereby they intermesh like a comb and form an approximately square-shaped pressing point, the axis of which lies in the main plane of extension or direction of the pliers. This arrangement favors the use of the crimping tool in confined spaces, for example in a control cabinet. It is also advantageous that a larger cross-sectional area of conductors between 0.5 and 6.0 mm² can already be served with these pliers. However, it is disadvantageous that the press cross section does not correspond to the desired trapezoidal cross section, but is approximately square. Due to the design of the press jaws, only two opposite points or surface areas are pressed in each plane transverse to the axis of the conductor, while the two remaining surface areas, offset by approximately 90 °, sag freely at the pressing point and can, in this respect, deform against the acting pressing pressure. The shape created by the feeding is therefore not optimal and not in accordance with DIN. Furthermore, there is the disadvantage that the pressed wire end sleeves have a slightly conical shape, especially when comparatively short wire end sleeves are used which cannot be inserted symmetrically to the articulation points of the press jaws into the pressing point. This conicity also tapers in the exact direction in which the wire end sleeve can be pulled out at its connection point, so that there is a risk that the screw connection will come loose when the screw connection is loosened or the conductor moves.

From US-A-2 743 634 a crimping tool for pressing wire end sleeves is known, in which two press jaws forming the pressing point are mounted on a common joint on one of the drive levers. One press jaw is supported on the drive lever itself, while in the power transmission path between the other press jaw and the other hand lever a jaw is switched on, which is slotted between its articulated articulation points in order to make it resilient. If an increased pressing force is required to achieve the compression of the wire end sleeve, the articulation points of the jaw and the pivot bearing of the hand levers approach a toggle-like dead center position, it then becoming possible for the walls of the slot of the jaw to be pressed against one another with the formation of a stop and thus the Transfer of a significantly increased pressing force is possible. It is also shown that, instead of the jaw, one press jaw and / or the other press jaw is slotted and thus designed to be flexible, in order to be able to provide the desired high pressing force using a toggle lever drive if this is required. This makes it possible to provide differently high pressing forces, as may be required when crimping ferrules. This crimping pliers is not concerned with the creation of a universal pliers with which an expanded cross-sectional area of wire end ferrules can be bridged.

From DE-B-21 49 167 a crimping tool is finally known in which it is possible to selectively press different cross sections. However, a separate press point is provided on the press jaws for each cross-section, so that it is not a universal crimping tool. With this known crimping tool there is a risk that the pressing points are mixed up, so that the pressing takes place at the wrong pressing point. In addition to the care, the application also requires additional handling handles.

The invention is based on the problem of developing a universal crimping pliers of the type described at the outset in which the spring jaw or the spring jaws are protected against overloading and nevertheless a comparatively large cross-sectional area of conductors with wire end sleeves can be properly pressed.

According to the invention, this is achieved in that at least one of the jaws has two areas acting on the press jaws, of which one area is largely rigid and the other area is a spring jaw is designed to be resilient, that at least one of the press jaws is guided on one of the areas of the jaw in the direction of movement of the press jaws, that between the press jaw and the resilient area of the jaw a first stop and counter-stop, and between the press jaw and the rigid area of the jaw second stop and counter-stop are provided, and that the distance between the two stops to the distance between the two counter-stops is dimensioned such that when crimping in a substantially cross-sectional area, the first stop and counter-stop are in active contact and only in the area of a maximum cross-section the second Stop and counterstop in the knitting system. It is sufficient that at least one of the jaws has two areas acting on the press jaws, but a symmetrical design is generally preferred, so that both jaws should each have a largely rigid area and a resiliently designed area. Through the appropriate cross-sectional dimensioning and arrangement, these two areas can be designed according to the respective functional purpose. It is important that both areas - albeit at different times - reach the knitting plant on the press jaws. Essentially, covered cross-sectional area, starting from the minimum conductor cross-section to the area of large cross-sections, the pressing force required to deform the wire end sleeve and the conductor is transmitted solely from the resilient regions of the jaws to the press jaws. The first stop on the press jaw and the first counter stop on the resilient area of the jaw are in contact with one another, that is to say in operative connection, at least in the press positions over the covered conductor cross-sectional area, so that the press forces are transmitted here. A spring movement takes place between the resilient area and the rigid area of the jaw. In the area of a maximum cross-section of a conductor to be pressed, which also has a certain, although small area can cover, the second stop on the press jaw and the second counter-stop on the rigid area of the jaw come into contact with one another and in operative connection, so that additional pressing force is then transmitted to the press jaws via the rigid areas of the jaw. This additional force is added to the maximum force that can be transmitted by the resilient areas of the jaws, or in other words, the pressing force required of the resilient area is limited to a maximum value, so that the resilient areas of the jaws are protected from overloading and plastic deformation which occurs as a result are protected. While in the generic state of the art the jaw is designed and acts as a spring jaw overall, two areas are created for the application subject to the jaw, namely a largely rigid area on the one hand and a largely resiliently designed other area which are functionally cleanly separated from each other. A compensating spring is, as it were, molded onto a rigid jaw.

With the new crimping pliers, a total cross-sectional area of conductors between 0.25 and 6.0 mm² can be crimped. This area is comparatively larger than with known crimping pliers in the prior art. The basic design of the new crimping pliers in connection with a double lever drive is particularly useful, so that a double ratio is provided in the drive, which on the one hand favors a short overall length of the pliers and nevertheless creates the possibility of applying considerable pressing forces for pressing large conductor cross sections. The short design also simplifies the handling of the crimping pliers, so that they can be used even in tight spaces, e.g. B. in control cabinets u. Like., Can be used. The new crimping pliers easily allows the advantageous end arrangement of the pressing point, so that the conductor with the attached ferrules on the end or can be inserted into the head of the crimping tool, i.e. in the main direction of extension of the crimping tool. In a double lever drive, the handles and the jaws are different parts, i.e. not in one piece, so that there is advantageously the possibility of using a comparatively higher quality material for the jaws in order to meet the requirements for the load capacity in the two areas of the jaws. The compressibility of an additional maximum cross section or a small cross-sectional area increases the overall compressible cross-sectional area beyond the range of elasticity. Nevertheless, the resilient areas of the jaws remain protected against overload even with such pressings. Since the jaws are formed in one piece with their rigid area and their resilient area, the new crimping pliers also have a small number of individual parts, which has a positive effect on the manufacturing and assembly costs.

The area of the jaw serving as a spring jaw can be applied with its first counter-stop to the first stop of the press jaw with the application of a prestressing force. This means that at least in the pressed position for the smallest conductor cross-section, but also in the open position of the crimping pliers, the first counter-stop and the first stop are already in contact with one another, with the pair of stops of the resilient region of the jaw already being under a prestressing force and this Preload force is intercepted on the rigid area of the jaw. Only in the pressing position for the smallest conductor cross-section does the pressing force no longer shift, or at least partially no longer, onto the rigid area of the jaw, but rather onto the wire end sleeve. The application of the pretensioning force is essential for ensuring that, even with small conductor cross sections, sufficiently high pressing forces are made available, as are required for proper pressing. Of the The closed position of the crimping pliers with small cross-sectional areas is therefore associated with a higher pressing force than with pliers in which the resilient areas act on the pressing jaws without pretensioning.

The jaw with its two regions can expediently be formed in one piece, the two regions being formed by a slot which is open at the edge and extends essentially parallel to the main direction of extension of the crimping pliers. Due to the slot design and arrangement, the two areas of the jaw can each be optimally designed according to their different requirements. The two areas also have a corresponding lever length so that they are able to transmit the desired forces.

It is particularly advantageous if the slot, beginning at the head-side end of the jaw, extends in the region of the press jaw to beyond the pivot bearing of the two jaws. In contrast to the prior art, the swivel bearing is not designed to be flexible, but instead has an axle journal on which the two jaws with their rigid regions are only pivotably suspended and supported. Since the slot can be made longer than the distance of the pivot pin that realizes the pivot bearing from the suspension point of the press jaws, the rigid region of the jaw advantageously has a small lever arm and the resilient region of the jaw advantageously has a larger lever arm, so that despite the compact construction, the crimping pliers accordingly large travel is accommodated. This large spring travel is required to cover the comparatively large cross-sectional area of conductors.

The jaws in plate construction can advantageously consist of a total of four plates, the rigid areas inside and the resilient areas are arranged outside; the resilient areas can be bent up and down out of the plane of the rigid areas. This design is matched in a special way to the contour of the press jaws and makes it possible to arrange the rigid areas of the jaw in a space-saving manner as it were in the outline of the press jaws and the resilient areas of the jaws outside of this outline. This also creates an attractive appearance of the head of the crimping tool. By bending the resilient areas out of the main extension plane of the pliers and the plate construction from a total of four plates, a construction that is also symmetrical to the main extension plane is nevertheless created.

For the realization and arrangement of the rigid and the resilient areas of the jaws and the guidance of the press jaws on parts of the jaws, various possibilities arise for the expert. Thus, the press jaws can be guided either on the rigid or on the resilient areas of the jaws, this guide generally only relating to a sliding guide in the direction of movement of the press jaws. It is possible to arrange the rigid regions of the jaws facing one another comparatively on the inside and the resilient regions of the jaws comparatively on the outside. This is advantageous in that the axle pin for the unrelenting pivot bearing can easily be arranged in the rigid area of the jaws. A single axle is sufficient here. In principle, however, it is also possible to arrange the resilient areas of the jaws on the inside and the rigid areas of the jaws comparatively on the outside. In this case, it is advisable to implement the swivel bearing using two axle journals and a connecting bridge.

An advantageous embodiment is the pressing jaws on the rigid areas of the jaws To guide the direction of movement of the press jaws with elongated holes. On the one hand, these elongated holes permit the necessary spring movement and, on the other hand, represent stops at the end of their elongated holes in order to limit the movement, to enable pretensioning and to protect the resilient areas against overload.

The drive of the jaws is expediently designed as a double lever drive, on the one hand to enable a small construction and on the other hand nevertheless to provide the high pressing forces required in the enlarged cross-sectional area in the area of large cross-sectional conductors.

The two press jaws can be suspended and guided against one another in the rigid regions of the jaws by bolts extending transversely to the main plane of extension of the crimping pliers, the press point being arranged in the main plane of extension for the end insertion of the ferrules. The press jaws are thus not only guided over the bolts, but also have surfaces with which they are supported directly against one another, so that despite the bolts and the elongated holes used, they do not have any significant pivoting movement, but rather a translational movement in their direction of movement during the pressing process To run. By guiding each other in the area of the press jaws, a conical design of the pressed ferrule is largely avoided.

On the other hand, the press jaws can also be suspended from the resilient areas of the jaws. This enables a particularly narrow construction. The jaws and the pressing jaws can be arranged in a housing which is open on the head side.

The pressing jaws can have such a contour in the contact area of the resilient areas of the jaws that the pretensioning force is only applied or increased during the closing of the crimping pliers. It is important that the pretensioning force is available at the desired height at the end of the closing process, specifically for relatively thin conductors, that is to say in the lower cross-sectional area. In the open position of the pliers, however, the pretensioning force should advantageously not yet be present or in any case be relatively small, in order to enable easy assembly of the pliers. A second reason is to be seen in the fact that the resilient areas of the jaw move slightly with respect to the outer contour of the pressing jaws against which they rest during the closing and opening of the crimping pliers, that is to say the stops or contact points move. Here, a friction force has to be overcome, which is greater the greater the pre-tensioning force. When opening the pliers a z. B. around the common axis of the handle effective return spring so that this described frictional force is overcome and thus the pliers is automatically transferred after a crimping in the open position. In order not to have to dimension this return spring too much, it makes sense to design the movement geometry in such a way that the biasing force in the open position of the pliers, i.e. when the return spring has also expanded and provides a relatively small return force, is relatively small is or is completely canceled. In contrast, a high biasing force in the closed position or in positions that are adjacent to the closed position does not interfere, because in such positions the return spring is also compressed comparatively far and provides an increased restoring force. The return spring must be dimensioned so that it provides a larger opening torque in all positions than that of the frictional force caused and overcome by the respective preloading force between the resilient area 8 and the contour of the press jaws 20 and 21 corresponds.

Figur 1

eine Draufsicht auf eine erste Ausführungsform der Universal-Crimpzange in geöffnetem Zustand,

Figur 2

eine Draufsicht auf die Crimpzange gemäß Figur 1 in geschlossenem Zustand,

Figur 3

eine Seitenansicht der Crimpzange gemäß den Figuren 1 und 2,

Figur 4

eine Einzeldarstellung einer Backe mit der zugehörigen Preßbacke,

Figur 5

eine Draufsicht auf die Preßbacken,

Figur 6

eine Stirnansicht der Preßbacken,

Figur 7

die Crimpzange gemäß den Figuren 1 bis 5 in der Preßstellung mit einer Aderendhülse mittleren Querschnittsbereichs,

Figur 8

die Crimpzange gemäß den Figuren 1 bis 5 in der Preßstellung mit einer Aderendhülse maximalen Querschnittsbereichs,

Figur 9

eine Prinzipsskizze mit einer am federnden Teil der Backe aufgehängten Preßbacke und

Figur 10

eine Prinzipsskizze einer Ausführungsform, bei der der starre Bereich der Backe außen angeordnet ist.

Embodiments of the invention are shown in the drawings and are described below. Show it:

Figure 1

2 shows a plan view of a first embodiment of the universal crimping tool in the open state,

Figure 2

2 shows a top view of the crimping pliers according to FIG. 1 in the closed state,

Figure 3

2 shows a side view of the crimping tool according to FIGS. 1 and 2,

Figure 4

an individual representation of a jaw with the associated press jaw,

Figure 5

a plan view of the press jaws,

Figure 6

an end view of the press jaws,

Figure 7

the crimping pliers according to Figures 1 to 5 in the pressing position with a ferrule middle cross-sectional area,

Figure 8

the crimping pliers according to Figures 1 to 5 in the pressing position with a wire end sleeve maximum cross-sectional area,

Figure 9

a schematic diagram with a press jaw suspended from the resilient part of the jaw and

Figure 10

a schematic diagram of an embodiment in which the rigid region of the jaw is arranged on the outside.

The essential components of the crimping pliers are two jaws 1 and 2, which are designed and arranged essentially symmetrically, on the one hand to a main extension plane 3, which forms the plane of the drawing in FIG. 1. On the other hand, there is also a largely symmetrical design with respect to a vertical center plane 4, which extends perpendicular to the main extension plane 3. The two jaws 1, 2 are designed in the manner of rocker arms and are pivotably mounted on an axle pin 5, but cannot be avoided. Since the jaws 1 and 2 must encompass each other in this area, the design deviating from the symmetrical design is also limited to this area. In principle, however, the jaws 1 and 2 are symmetrical, it being understood that an asymmetrical design would also be possible.

Each individual jaw 1 or 2 (cf. also FIG. 3) is divided by a slot 6 which is open at the edge into a region 7 which is largely or as rigid as possible and a resilient region 8 which can also be referred to as a spring jaw. If one considers a jaw known in the prior art as a largely rigid component, a spring jaw is, as it were, molded onto such a rigid jaw.

At the rear ends of the jaws 1 and 2, a drive 9 engages for the required pivoting movement of the jaws 1 and 2. For this purpose, a handle 11 is pivotally articulated on the jaw 1 via an axle pin 10. In a symmetrical arrangement, a handle 13 engages the jaw 2 via an axle pin 12. The two handles 11 and 13 are formed as metal moldings and each surrounded by a plastic coating 14, 15. The two handles 11 and 13 are pivoted to one another about a common pivot pin 16, in such a way that when the handles 11 and 13 are pressed together, the axle pins 10 and 12 move apart or move apart so that the jaws 1 and 2 are ultimately pivoted towards each other at their other ends. As can be seen, a double lever drive is formed.

At the front ends of the jaws 1 and 2, a pressing point 17 is formed, into which the stripped end of a conductor 18 (FIG. 4) with an attached ferrule 19 from the end face into the pressing point 17 in the direction parallel to the direction of the section line between the main extension plane 3 and the vertical center plane 4 can be inserted. The press point 17 is formed by two press jaws 20 and 21, the press jaw 20 being suspended with a bolt 22 which is arranged on the rigid region 7 of the jaw 1 (see also FIG. 3). Likewise, the press jaw 21 is suspended and guided via a bolt 23 at the front end of the rigid region 7 of the jaw 2. The press jaws 20 and 21 are also brought together so that they perform a largely translational movement despite a largely rotary movement of the bolts 22 and 23.

Around the bolt 22, which is arranged in the rigid region 7 of the jaw 1, the press jaw 20 has an elongated hole 24. Correspondingly, the press jaw 21 has an elongated hole 25. The resilient regions 8 of the jaws 1 and 2, which are arranged on the outside in comparison to the rigid regions 7, bear against the press jaws 20 and 21 from the outside, with a first stop 26 on the press jaw 20 or 21 on a first counterstop 27 in the active system or at least comes in the active position in the pressing position of the crimping tool. The first stops 26 are provided on the press jaws 20 and 21. The first counter stops are provided on the resilient areas 8 of the jaws 1 and 2. Second stops 28 are also provided on the pressing jaws 20 and 21 and are formed by the inner ends of the elongated holes 24 and 25. This includes second counter-stops 29, which to the rigid areas 7 of the jaws 1 and 2 are provided and are formed here by the bolts 22 and 23. It can be seen from FIG. 1 that the first pair of stops 26, 27 are in contact, while in the second pair of stops the stops 28 are removed from the respective counter-stops 29. The distance corresponds to the intended possibility of movement of the bolts 22 or 23 in the elongated holes 24 or. 25. The resilient areas 8 of the jaws 1 and 2 are applied to the press jaws 20 and 21 with the application of a preload, this preload force being transmitted via the stop pair 26 and 27 to the bolts 22 and 23 and to the regions of the elongated holes 24 and 25 supports that represent the other end of the elongated holes 24 and 25 compared to the stops 28. From this it can already be seen that the pressing jaws 20 and 21 on the bolts 22 and 23 are guided towards and away from one another only in the direction of movement of the pressing jaws 20 and 21 by means of the elongated holes 24 and 25.

Figure 2 shows the crimping tool in the closed state, but without a conductor inserted into the pressing point 17. It can be seen in comparison to FIG. 1 that by pivoting the two handles 11 and 13 towards one another, the two axle journals 10 and 12 have moved apart, so that the jaws 1 and 2 have carried out a corresponding pivoting movement about the common axle journal 5. The press jaws 20 and 21 are moved towards each other until they are the smallest distance apart. The closing force is transmitted via the stop pairs 26, 27. The resilient areas 8 of the jaws 1 and 2 are still in contact with the press jaws 20 and 21. Apart from a slight rotary movement, the bolts 22 and 23 still rest on the same side of the elongated holes 24 and 25, as in the open position according to FIG. 1. During this movement, the pressing jaws 20 and 21 were guided on the bolts 22 and 23 so that they support each other by their own support have a translatory movement towards each other, as shown in Figure 2 in the end position.

In the drawings, in particular FIGS. 1 and 2, a known positive lock is shown in the area between the handles 11 and 12, which ensures that the crimping tool can only be opened again after the closed position has been properly reached. This defines an identical closed position for all cross-sectional areas, at least between the handles 11 and 13, so that with different cross-sections to be pressed and the resulting different paths between the resilient areas 8 in connection with the respective end position of the pressing jaws 20 and 21 pressing and deformation forces of different magnitudes, as are required for the different cross sections, are provided.

Figure 3 shows the special shape of the resilient areas 8 relative to the rigid areas 7. The two press jaws 20 and 21 each have a recess 30, 31 (FIG. 6) on their outside, in which the rigid regions 7 of the jaws 1 and 2 come to rest. The resilient areas 8 are now bent out of the main extension plane 3 so that they rest on the press jaws 20, 21, specifically on the stops 26 formed there.

Figure 4 again illustrates the special individual design of the jaws using the example of the jaw 1 and the suspension of the associated press jaw 20. It can also be seen here that the first stop 26 on the press jaw 20 and the first counter-stop 27 on the resilient area 8 of the press jaw 1 in Knitting system, while the second stop 28 on the press jaw 20 is still at a corresponding distance from the second counter-stop 29 on the rigid region 7 of the press jaw 1. The head 18 on its front The end is stripped is shown with an attached, unpressed ferrule 19 in its front or head insertion direction relative to the press jaw 20.

In Figures 5 and 6, the two press jaws 20 and 12 are shown separately, namely in an extended state, so that their shape can be seen. The press jaw 20 has the slot 24 for the passage of the bolt 22. On both sides in the area of the large areas, recesses 32 and 33 are provided, which are assigned to projections 34 and 35 on the press jaw 21. Guide surfaces 36 are formed between the recess 32 and the projection 34, while the projection 34 is equipped with corresponding counter surfaces 37. The same applies to the recess 33 and the projection 35. This ensures that the press jaws 20 and 21 always pivot about the bolts 22 and 23 so that the press jaws themselves perform a translatory movement. Tilting or tilting, which could lead to a taper of the pressed ferrule 19, is thus avoided. An axially continuous, die-shaped channel 38 is provided in the interior of the press jaw 20 and a male-shaped punch 39 is provided in the area of the press jaw 21, which are matched to one another in their arrangement and design and form the trapezoidal cross section between them when the ferrules 19 are pressed. The plunger 39 has cams 40 on its end face, which are molded into the material of the ferrule 19 along a trapezoidal side. It can be seen that channel 38 and punch 39 form the pressing point 17, in which the material of the ferrule 19 is enclosed at almost 360 ° and is pressed.

FIGS. 7 and 8 show the crimping pliers in the closed position, each with an inserted conductor with an end sleeve that is being pressed. FIG. 7 shows the relative position of the parts when a conductor with a cross section of approximately 2 mm 2 is pressed. This represents an average size approximately in the lower third of the cross-sectional area. FIG. 8, on the other hand, shows the pressed position of a conductor with a maximum cross-sectional area, that is to say in the order of magnitude of 6.0 mm 2.

It can be seen from FIG. 7 that the pressing jaws 20 and 21 have enclosed the wire end sleeve 19 and the enclosed conductor with their channel 38 and punch 39 and have been placed thereon in a deforming manner. By compressing the two handles 11 and 13, the required pressing force has been applied, which is greater than the pretensioning force of the resilient areas 8. These resilient areas 8 have therefore spring open further compared to the position according to FIG. 2, so that the slots 6 are comparatively have become wider. No force is transmitted to the press jaws 20 or 21 via the rigid regions 7. Due to the comparatively springing open of the resilient areas 8, the rigid areas 7 have pivoted somewhat inwards, so that the bolts 22 and 23 have covered a small distance in the elongated holes 24 and 25, but are free from both ends of the elongated holes.

FIG. 8 shows that when a conductor with a maximum large cross section is pressed, the resilient regions 8 have reached their maximum deflection. The slots 6 are maximally wide here and the rigid areas 7 are in such a position relative to the pressing jaws 20 and 21 that the bolts 22 and 23 with their counter stops 29 have now been placed on the second stops 28 at the end of the elongated holes 24 and 25 . In this way, an additional force required for pressing the maximum cross section is transmitted to the pressing jaws 20 and 21 via the rigid regions 7. Of course, the part of the pressing force which is transmitted via the resilient regions 8 also acts in this state. However, this partial force of the resilient areas 8 is limited because the resilience of the resilient areas 8 is limited. The jaws 1, 2 are thus protected from overloading with regard to their resilient regions 8.

FIG. 9 shows a further possible embodiment of the crimping pliers, specifically on a representation similar to that in FIG. 4. Only the jaw 1 is shown. The jaw 2 is designed accordingly. Here, too, the jaw 1 is divided by the slot 6 into the rigid area 7 and the resilient area 8. In contrast to the exemplary embodiment described above, however, the associated press jaw 20 is suspended from the resilient region 8 of the jaw 1, specifically with the aid of the bolt 22, about which the press jaw 20 can pivot, but cannot move longitudinally. The first stop 26 and the first counter-stop 27 are thus formed here in the region of the bolt 22. The second stop 28 is provided by a pin 41, which can also be designed as a projection on the press jaw 20. The associated counter-stop 29 is formed by the rigid region 7 of the jaw 1. It can be seen that when pressing essentially the cross-sectional area apart from the maximum area, the pressing forces are transmitted to the pressing jaws 20 and 21 solely via the resilient areas 8, the stop 28 approaching the stop 29 more or less closely. The distance between the stops 28 and 29 is only used up when a maximum conductor cross section is pressed. The resilient area 8 experiences its maximum suspension and an additional pressing force is transmitted via the rigid area 7.

Figure 10 shows an embodiment with a simple lever drive. In addition, the rigid region 7 and the resilient region 8 of the jaw 1 have changed their relative position, ie the resilient region 8 is located comparatively on the inside, so that the first stop 26 is formed by a projection 42 on the press jaw 20. This is assigned to the first counter-stop 27 on the resilient area 8. The Press jaw 20 is suspended from the bolt 22, which in turn is seated in the rigid region 7 of the jaw 1. The press jaw 20 has the elongated hole 24, so that here the second stop 28 on the press jaw 20 is formed by the outer end of the elongated hole 24, while on the other hand the bolt 22 forms the corresponding counter stop 29. Here too, the resilient area 8 can be set with a prestressing force. However, it can be seen that the width of the slot 6 is reduced here when the growing conductor cross sections are pressed. Here, too, the maximum suspension of the resilient area 8 is limited by the second stop 28 and the second counter-stop 29.

Claims (11)

1. Pliers for crimping wire end ferrules (19) with two jaws (1, 2) held in a pivot bearing, said jaws being swivellable about the pivot bearing by means of a drive (9) comprising two hand levers and each of said jaws (1, 2) being provided with a flexible jaw, whereby the drive acts upon the one end of said jaws (1, 2) and a cheek plate (20, 21) each is connected to each of the other ends of said jaws (1, 2), said cheek plate comprising a single pressing position (17) for universally covering a cross-sectional area, wherein at least one of the jaws (1, 2) comprises two areas (7, 8) acting upon the cheek plates (20, 21), of which the one area (7) is arranged substantially rigid and the other area (8) is yieldingly and resiliently arranged as a flexible jaw, and at least the one of the cheek plates (20, 21) is guided in one of the areas of the jaw (1, 2) in the direction of movement of the cheek plates, and between the cheek plate (20, 21) and the resilient area (8) of the jaw (1, 2) a first stop (26) and a counterstop (27) are provided and between the cheek plate and the rigid area (8) of the jaw (1, 2) a second stop (28) and a counterstop (29) are provided, and the distance between the two stops (26, 28) is dimensioned with respect to the distance between the two counterstops (27, 29) in such a way that during the crimping at first the first stop (26) and the counterstop (27) come to sit close with full effect in the substantial cross-sectional zone and that the second stop (28) and the counterstop (29) come to sit close to one another with full effect only in the area of a maximum cross section.
2. Pliers in accordance with claim 1, wherein the area (8) of the jaw (1, 2) serving as spring jaw sits close to the first stop (26) on the cheek plate (20, 21) with its first counterstop (27) under the exertion of an initial tension.
3. Pliers in accordance with claim 1 or 2, wherein the jaw (1, 2) with its two areas (7, 8) is arranged in one piece and the two areas are formed by a slot (6), said slot comprising an open edge on the lateral side and extending substantially parallel to the pliers' main direction of extension.
4. Pliers in accordance with claim 3, wherein the extension of said slot (6) begins at the head end of the jaw (1, 2) in the area of the cheek plate (20, 21) and extends beyond the pivot bearing (5) of the two jaws (1, 2).
5. Pliers in accordance with one or several of the claims 1 to 4, wherein the jaws (1, 2) have a plate design consisting of a total of four plates, and the rigid areas (7) are arranged in the interior and the resilient areas (8) are arranged on the outside, and the resilient areas (8) are bent upwardly and downwardly from the rigid areas (7).
6. Pliers in accordance with one or several of the claims 1 to 5, wherein the cheek plates (20, 21) are guided in the rigid areas (7) of the jaws (1, 2) by means of oblong holes (24, 25) in the direction of movement of the cheek plates (20, 21).
7. Pliers in accordance with claim 1, wherein the drive (9) of the jaws (1, 2) is arranged as double lever drive.
8. Pliers in accordance with one or several of the claims 1 to 7, wherein the two cheek plates (20, 21) are suspended and guided against each other in the rigid areas (7) of the jaws (1, 2) through bolts (22, 23) extending transversally to the main extension plane (3) and that the pressing position (17) is arranged in such a way as to allow the frontal insertion of the wire end ferrules in the main extension plane (3).
9. Pliers in accordance with one or several claims 1 to 5, wherein the cheek plates (20, 21) are suspended in the resilient areas (8) of the jaws (1, 2).
10. Pliers in accordance with one or several of the claims 1 to 9, wherein the jaws (1, 2) and the cheek plates (20, 21) are arranged in a casing which is open on the head side.
11. Pliers in accordance with claim 2, wherein the cheek plates (20, 21) have such a profile in the contact zone of the resilient areas (8) of the jaws (1, 2) that the initial tension is only exerted or increased during the closure of the pliers.

Images