EP3012923A1 - Jointing clamp - Google Patents

Abstract

The invention relates to a pressing tongs (1). The pressing tongs have a spring element, which is arranged in the power flow between hand levers (3, 5) and dies (12). The spring element (7) forms a force-displacement compensating element (8), which enables workpieces with different cross-sectional areas to be pressed together with the pressing tongs (1). According to the invention, the spring element (7), which forms the force-displacement compensation element (8), is formed in the region of the pliers head (4) of the pressing pliers (1). Preferably, the spring element (7) is a circular arc spring or spiral spring (44), which extends in the circumferential direction about the Gesenkachse (13).

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a pressing tongs for pressing a workpiece. This may be any pressing tongs, for example a pressing tongs for pressing pipe or pipe connections or a pressing tongs (which is also referred to as crimping tool) for pressing electrical line connections or plugs, sleeves or jacks with any electrical conductors. In this case, the crimping pliers may in principle have any of the various known constructive embodiments and drive mechanisms, wherein crimping with two or more dies or spikes (hereinafter collectively referred to as "dies") may take place during the pressing process. It is possible that the crimping tool is operated by external force, for example by means of an electric drive. Preferably, however, it is a hand-operated pressing tongs.

STATE OF THE ART

During the pressing of a workpiece, the increasing plastic deformation of the workpiece between the dies causes a pressing force which increases during the pressing process. In known pressing tongs the translation of manually applied to hand lever of the pressing tongs hand forces to the dies by means of a drive mechanism is such that the required maximum pressing forces can be generated by manual operation of the hand lever. In principle, in the case of known pressing tongs, first of all the force flow took place via as rigid as possible components of the pressing tongs.

The aim is that a pressing tongs can be used not only for pressing workpieces with a single geometry, a material rigidity and / or cross-sectional area (in the following simplified "" cross-sectional area), but also multifunctional for different workpieces with different cross-sectional areas Design of the components of the pressing tongs the pressing tongs designed for the compression of a workpiece with a predetermined cross-sectional area, the use of the pressing tongs for a workpiece with a smaller cross-sectional area with the result that in this application the required maximum pressing forces are not achieved while using the pressing tongs for Workpieces with a larger cross-sectional area after a partial stroke of the hand lever, the maximum pressing forces are generated so that the complete closure of the hand lever would lead to excessive pressing forces or the complete closure of the hand lever by manual operating forces is not possible. Remedy could only be provided in the past by equipping the pressing tongs with replaceable heads or interchangeable dies for the different cross-sectional areas of the workpieces.

According to the non-prepublished European patent application EP 13 176 918.4 It is proposed to provide a pressing tool with a drive mechanism which has a mechanical pressing force limiting device. The mechanical pressing force limiting device limits the pressing force brought about by the pressing tool, irrespective of the size of a pressing stroke, to a predetermined set pressing force. With such a pressing force limiting device, basically, the driving mechanism of the pressing tool can be designed so that when pressing a workpiece having a small cross sectional area, the required pressing force is brought about. If workpieces with larger cross-sectional areas are then used in such a pressing tool, excessive pressing forces or excessive actuating forces are avoided by triggering the mechanical pressing force limiting device. However, the mechanical pressing force limiting device drastically increases the design effort.

• Die Druckschrift EP 0 732 779 B1 offenbart eine Presszange zum Verpressen einer Aderendhülse mit einem abisolierten elektrischen Leiter. Die Presszange verfügt über einen Zangenkopf. Der Zangenkopf ist gebildet mit einem Grundkörper. Der Grundkörper ist fest mit einem festen Handhebel verbunden. Gegenüber dem Grundkörper ist ein Schwenkring um eine Gesenkachse verdrehbar. Der Schwenkring besitzt im Bereich seiner Innenfläche radiale Ausnehmungen, womit eine Art Keilwellenprofil gebildet ist. Sechs Pressstempel sind gleichmäßig um die Gesenkachse verteilt angeordnet. Die Pressstempel sind jeweils an von dem Grundkörper gehaltenen Schwenkbolzen verdrehbar gelagert. In dem dem Gesenk abgewandten Endbereich finden die Pressstempel jeweils Aufnahme in einer der keilwellenartigen Ausnehmungen des Schwenkrings. Die Verdrehung des Schwenkrings hat eine gemeinsame Verschwenkung der Pressstempel zur Folge. Radial innenliegende Gesenkflächen der Pressstempel bilden eine in Umfangsrichtung weitestgehend geschlossene Gesenkkontur aus, deren Querschnittsfläche sich mit der Verdrehung des Schwenkrings und der damit einhergehenden Verdrehung der Pressstempel verringert, womit das Verpressen der Aderendhülse erfolgt. Die Betätigung des Zangenkopfs in Form der Herbeiführung einer relativen Verdrehung des Schwenkrings gegenüber dem Grundkörper erfolgt über einen an dem Schwenkring angelenkten Antriebs- oder Schwenkbolzen. Der Antriebs- oder Schwenkbolzen ist Bestandteil eines Schwenklagers, mittels welchem ein Endbereich eines beweglichen Handhebels an dem Schwenkring angelenkt ist. Über ein weiteres Schwenklager ist, geringfügig beabstandet von dem zuvor genannten Schwenklager, an dem beweglichen Handhebel ein Druckhebel angelenkt, wobei dieses Schwenklager ein Kniegelenk ausbildet. Der Druckhebel ist in dem dem Kniegelenk abgewandten Endbereich an dem festen Handhebel angelenkt. Hierzu bildet der Druckhebel eine Lagerkugel aus, die Aufnahme findet in einer von dem festen Handhebel ausgebildeten Lagerschale. Eine in Öffnungsrichtung der Presszange wirkende Rückstellfeder ist mit einem Federfußpunkt unmittelbar an dem Schwenkring angelenkt, während der andere Federfußpunkt der Rückstellfeder an dem festen Handhebel angelenkt ist. Der Druckhebel besitzt abseits des Verbindungsbereichs zwischen dem Kniegelenk und der Lagerkugel einen mit einer Verzahnung ausgestatteten Teilumfang, welcher in Wechselwirkung tritt mit einem Sperrelement. Das Sperrelement ist verdrehbar an dem beweglichen Handhebel gelagert und über eine zwischen Sperrelement und beweglichem Handhebel wirkende Feder in eine Gleichgewichtslage beaufschlagt. Mit der Verzahnung des Druckhebels und dem Sperrelement ist ein Zwangsgesperre gebildet, mittels dessen gewährleistet werden soll, dass eine einmal erreichte Pressstufe der Presszange auch bei Verringerung der auf die Handhebel aufgebrachten Betätigungskräfte gesichert ist, ohne dass eine Öffnungsbewegung des Zangenkopfs erfolgen kann. Vielmehr ist eine Öffnungsbewegung erst dann möglich, wenn der Druckhebel vollständig den vorgegebenen Arbeitshub durchlaufen hat. Die Druckschrift EP 0 732 779 B1 beschreibt die Problematik, dass grundsätzlich bei einer Presszange mit einem Zwangsgesperre über das Zwangsgesperre eine Endstellung vorgegeben ist, welche mit einer vorbestimmten Endgröße der Gesenkkontur korreliert. Werden mit der Presszange Werkstücke unterschiedlicher Größen (beispielsweise wegen Toleranzen bei der Herstellung des Werkstücks oder des Einsatzes unterschiedlicher Typen von Werkstücken) verpresst, so muss ein Verpressen immer bis zu der genannten Endgröße der Gesenkkontur erfolgen. Unabhängig von der Größe des Werkstücks ist der Arbeitshub somit immer derselbe, während die wirkenden Presskräfte von der Größe des Werkstücks abhängig sind. Dies beeinträchtigt u. U. die Gleichmäßigkeit und Qualität des Pressergebnisses. Möglich ist auch, dass es zu Beschädigungen bis hin zu einem Bruch von Komponenten der Presszange durch eine Überlastung derselben kommen kann. Vor diesem Hintergrund schlägt die Druckschrift EP 0 732 779 B1 vor, den Kugelzapfen des Druckhebels nicht starr abzustützen. Vielmehr ist gemäß der Druckschrift EP 0 732 779 B1 der feste Handhebel im Verbindungsbereich zwischen dem Grundkörper und der Lagerschale elastisch ausgebildet. Je nach Größe der wirkenden Presskraft kann somit die Lagerschale einfedern. Die Einfederung der Lagerschale ermöglicht die Bewegung der Handhebel aufeinander zu, ohne dass es zu einer Verdrehung des Schwenkrings gegenüber dem Grundkörper und damit einer weiteren Verringerung der Querschnittsfläche der Gesenkkontur kommt. Für ein größeres Werkstück kann somit gemäß der Druckschrift EP 0 732 779 B1 die Endstellung des Zwangsgesperres erreicht werden, indem zunächst in einem Presshub die Pressstempel in einem Ausmaß aufeinander zu bewegt werden, welcher kleiner ist als das Ausmaß der Bewegung der Pressstempel aufeinander zu für ein kleineres Werkstück. Eine weitere Bewegung der Handhebel aufeinander zu führt dann zu keiner weiteren Bewegung der Pressstempel aufeinander zu, sondern zu einer elastische Verformung des festen Handhebels. Möglich ist auch eine Überlagerung der Bewegung der Pressstempel und der Verformung des festen Handhebels. Um eine hinreichende Elastizität der Abstützung der Lagerschale zu gewährleisten, ist der feste Handhebel mit zwei Handhebelteilen ausgebildet, welche in einem Endbereich V-förmig miteinander verbunden sind. In einem anderen Endbereich bildet ein Handhebelteil die Lagerschale aus, während der Endbereich des anderen Handhebelteils fest mit dem Grundkörper des Zangenkopfes verbunden ist oder diesen ausbildet. Beide Handhebelteile sind elastisch ausgebildet. Hierzu ist das die Lagerschale ausbildende Handhebelteil in Richtung der Lagerschale verjüngt ausgebildet, während das andere Handhebelteil eine Einschnürung in einem Ausmaß besitzt, dass dieser bei den wirkenden Handkräften elastisch verformbar ist. Der starre Verbindungsbereich der beiden V-förmigen Handhebelteile muss derart gestaltet sein, dass in diesem Verbindungsbereich die Betätigung der Presszange durch die Hand des Benutzers möglich ist. Gemäß der Druckschrift EP 0 732 779 B1 erfolgt die Verbindung der beiden Handhebelteile über eine formschlüssige Verbindung über Querbolzen und längsgeprägte Noppen. Die mittels der elastischen Abstützung des Druckhebels im Bereich der Lagerschale herbeigeführte Wirkung wird in der Druckschrift EP 0 732 779 B1 auch als "Kraft-Weg-Ausgleich" bezeichnet.

Other known configurations of pressing tongs are based on the idea that the unwanted increase of the manual operating force and the maximum pressing force on the dies can be reduced or avoided if the drive mechanism is not provided with rigid components, but rather a targeted elasticity is provided in the drive mechanism. When pressing a workpiece with too large a cross-sectional area any elasticity in the drive mechanism does not (only) to a plastic deformation of the workpiece, but rather gives the drive mechanism due to the elastic component, so ideally without further plastic deformation of the workpiece, the hand lever alone under elastic deformation of the drive mechanism can be closed. Embodiments based on this principle are known from the following publications:

• The publication EP 0 732 779 B1 discloses a crimping tool for crimping a ferrule with a stripped electrical conductor. The pressing tongs have a pliers head. The pliers head is formed with a base body. The body is firmly connected to a fixed hand lever. Compared to the main body, a pivot ring about a Gesenkachse is rotatable. The swivel ring has in the region of its inner surface radial recesses, whereby a kind of splined shaft profile is formed. Six punches are evenly distributed around the die axis. The press punches are each rotatably mounted on pivot pins held by the base body. In the end region facing away from the die, the press punches each receive in one of the wedge-shaft-like recesses of the swivel ring. The rotation of the pivot ring has a common pivoting of the ram result. Radial internal Gesenkflächen the ram form a circumferentially largely closed Gesenkkontur whose cross-sectional area is reduced with the rotation of the pivot ring and the concomitant rotation of the ram, whereby the compression of the ferrule takes place. The operation of the pliers head in the form of bringing about a relative rotation of the pivot ring relative to the base body via a hinged to the pivot ring drive or pivot pin. The drive or pivot pin is part of a pivot bearing, by means of which an end portion of a movable hand lever is articulated to the pivot ring. About a further pivot bearing is, slightly spaced from the aforementioned pivot bearing, hinged to the movable hand lever, a pressure lever, said pivot bearing forms a knee joint. The pressure lever is articulated in the end facing away from the knee joint on the fixed hand lever. For this purpose, the pressure lever forms a bearing ball, the recording takes place in a bearing shell formed by the fixed hand lever. An acting in the opening direction of the pressing pliers return spring is hinged with a Federfußpunkt directly to the pivot ring, while the other spring base of the return spring is hinged to the fixed hand lever. The pressure lever has, apart from the connecting region between the knee joint and the bearing ball, a partial circumference equipped with toothing, which interacts with a blocking element. The blocking element is rotatably mounted on the movable hand lever and acted upon by a spring acting between locking element and movable lever spring in an equilibrium position. With the teeth of the pressure lever and the locking element is a Zwangsgesperre formed by means of which it is to be ensured that a pressing stage of the pressing tongs once achieved is secured even when reducing the applied to the hand lever actuating forces without an opening movement of the pliers head can take place. Rather, an opening movement is only possible when the pressure lever has completed the predetermined stroke. The publication EP 0 732 779 B1 describes the problem that in principle in a pressing tongs with a Zwangsgedperre on the Zwangsgesperre an end position is predetermined, which correlates with a predetermined final size of the Gesenkkontur. If workpieces of different sizes (for example because of tolerances in the production of the workpiece or the use of different types of workpieces) are pressed with the pressing tongs, then pressing must always be carried out up to the stated final size of the die contour. Regardless of the size of the workpiece, the working stroke is thus always the same, while the acting pressing forces depend on the size of the workpiece. This affects u. U. the uniformity and quality of Pressergebnisses. It is also possible that it can damage up to a fraction of components of the pressing tongs by overloading the same. Against this background, the document proposes EP 0 732 779 B1 not rigidly support the ball stud of the pressure lever. Rather, according to the document EP 0 732 779 B1 the fixed hand lever is elastically formed in the connecting region between the base body and the bearing shell. Depending on the size of the acting pressing force can thus compress the bearing shell. The deflection of the bearing shell allows the movement of the hand lever toward each other, without causing a rotation of the pivot ring relative to the base body and thus a further reduction in the cross-sectional area of the die contour. For a larger workpiece can thus according to the document EP 0 732 779 B1 the end position of the Zwangsgesperres be achieved by first in a pressing stroke, the press dies are moved towards each other to an extent which is smaller than the extent of movement of the press dies towards each other for a smaller workpiece. Further movement of the hand lever toward each other then leads to no further movement of the ram toward each other, but to an elastic deformation of the fixed hand lever. It is also possible a superposition of the movement of the punch and the deformation of the fixed hand lever. In order to ensure a sufficient elasticity of the support of the bearing shell, the fixed hand lever is formed with two hand lever parts, which are connected to each other in an end region V-shaped. In another end region forms a hand lever part of the bearing shell, while the end portion of the other hand lever part is fixedly connected to the main body of the pliers head or this forms. Both hand lever parts are elastic. For this purpose, the bearing shell forming hand lever part is tapered in the direction of the bearing shell, while the other hand lever part has a constriction to an extent that this is elastically deformable in the acting hand forces. The rigid connection region of the two V-shaped hand lever parts must be designed such that in this connection region the operation of the pressing tongs by the user's hand is possible. According to the document EP 0 732 779 B1 the connection of the two hand lever parts via a positive connection via transverse bolts and longitudinal embossed knobs. The effect brought about by means of the elastic support of the pressure lever in the region of the bearing shell is described in the publication EP 0 732 779 B1 also referred to as "force-displacement compensation".

Also according to EP 0 158 611 B1 It is proposed to elastically support the articulation point of the pressure lever to the fixed hand lever. This is done here via the arrangement of a bearing of the pressure lever bearing pin in a slot of the fixed hand lever, wherein the bearing pin can move under the action of a coil spring along the slot.

DE 31 09 289 C2 also proposes resiliently supporting a pressure lever, here for a pressing tongs with scissor-type pressing jaws. In this case, the elastic support of the pressure lever is ensured by the lever in the region of the articulation point for the pressure lever has a taper in the form of a slot which leads to a branch of the fixed hand lever with a reduction in the material cross section of the fixed hand lever in the branch. This reduction of the material cross-section leads to an elastic deformation of the fixed hand lever in the acting pressing forces.

The non-prepublished European patent application EP 14 154 206.8 relates to a pressing tongs in which the drive mechanism is formed with a toggle mechanism. Here, the elasticity of the drive mechanism is not provided in the region of the bearing of the pressure lever, but rather in the pressure lever itself. For this purpose, the pressure lever is curved or cranked and flexible formed.

OBJECT OF THE INVENTION

The invention has for its object to provide an alternative and / or improved embodiment of a pressing tongs, which for pressing workpieces with different Cross-sectional surfaces can be used. In particular, the invention has for its object to equip the crimping pliers with an alternative or improved force-displacement compensation element.

SOLUTION

The object of the invention is achieved with the features of the independent claim. Further preferred embodiments according to the invention can be found in the dependent claims.

DESCRIPTION OF THE INVENTION

The pressing tool according to the invention has two drive elements, in which it may be in the formation of pressing tongs as a manually operated pressing tongs to handle or hereby coupled components. The pressing tongs invention also has a pliers head. In the region of the pliers head actuating elements are arranged, which actuate the dies, between which the workpiece is pressed. These actuators can be fixed (but quite replaceable) coupled with the dies or directly interact with them (see, the documents EP 0 732 779 B1 . DE 10 140 270 B4 and DE 10 2005 003 615 B3 in which an actuating element is designed as a pivot ring, bear against the contact surfaces against contact surfaces of the dies, wherein a pivoting of the pivot ring, the movement of the dies has the consequence).

According to the invention, a spring element is provided in the pressing tongs. The spring element is arranged in the power flow between the drive elements and the dies and forms a force-displacement compensation element. In the context of the invention, a force-displacement compensating element is understood in particular to be a spring element which can be applied to the drive forces that can be applied to the drive elements (ie the maximum force of a power-operated drive or the maximum manual force) during a blocking of the closing movement of the dies (in particular with a Workpiece with too large a cross-section or as rigid a test specimen) allows a closing movement of the drive elements of at least 10% (for example, at least 20%, 30%, 50% or even 70% or 100%) of the entire working stroke of the drive elements. By means of the use of such a force-displacement compensating element The range of application of the pressing tongs can be extended for pressing workpieces with different cross-sectional areas.

The embodiments known from the prior art arrange the spring element, which forms the force-displacement compensating element, in the region of hand levers or the toggle mechanism: According to the publication EP 0 732 779 B1 Both a hand lever and a support arm for a toggle lever is designed to be elastic. The pamphlets EP 0 158 611 B1 and DE 31 092 89 C2 suggest the elastic configuration of a pivot point of the pressure lever, while the not vorveröffentliche patent application EP 1 415 4 206.8 proposes the elastic design of the pressure lever.

According to the invention, it has been recognized for the first time that there is an alternative or cumulative location for the arrangement of the force-displacement compensating element and / or an alternative or cumulative component for the formation of the force-displacement compensating element forming spring element the spring element, which forms the force-displacement compensating element, is formed in the region of the pliers head. Here, the force-displacement compensating element may for example be integrated into a kind of housing of the pliers head, where this is only partially or not visible from the outside. In the event that the pliers head is formed in a kind of plate construction, the spring element which forms the force-displacement compensating element may be at least partially disposed between cover plates of the pliers head.

For an embodiment of the pressing tongs according to the invention, a drive mechanism of any configuration is provided, which is interposed between the drive elements and the actuating elements. To name just one example, this drive mechanism can be designed as a toggle mechanism. For this proposal, the spring element which interposed the force-displacement compensating element in the power flow between the drive mechanism and the actuators. In other words, the spring element is arranged in the power flow after the drive mechanism, in which case the spring element is not part of the toggle mechanism for the design of the drive mechanism as a toggle mechanism.

The integrated into the pliers head and the force-displacement compensating element forming spring element can be arbitrarily coupled to the other components of the pressing pliers, for example be integrally connected with another component or be attached in several pieces to this, be hinged to this in the region of a Federfußpunktes or be performed in the region of a Federfußpunktes or in any area of the spring element. For an embodiment of the pressing tongs according to the invention, a spring base of the spring element is attached to one of the actuating elements, this also being understood to mean a one-piece design of the spring element with this actuating element. For example, the spring base of the spring element may be fastened to an actuating element designed as a pivot ring.

There are many possibilities for the design of the spring element. Thus, the spring element may be formed for example as a tension or compression spring. For a particular embodiment of the invention, the spring element is designed as a bending beam. Here, the bending beam may have any geometry, for example, be formed straight or curved. By the choice of the course of the neutral fiber of the bending beam, the choice of material of the spring element and the bending stiffness, in particular the area moment of inertia of the bending beam, it is possible to influence the elasticity of the spring element and the deformation behavior of the spring element.

In a particular embodiment of this idea, the spring element formed as a bending beam is designed in plate construction. This allows a particularly simple production of the spring element, wherein depending on the design of the individual plates of the spring element targeted and with high accuracy, the elastic behavior of the spring element can be specified. It is even possible that pressing tongs are provided with different characteristics of KraftWeg-Ausgleichselements by a different number of otherwise identical plates is used for the different spring elements. Under some circumstances, a plate construction may also be advantageous if the spring element is formed integrally with another component of the pressing tongs, in particular an actuating element or the swivel ring, so that both the spring element and the other component can be manufactured by means of the same plate and the production method used therefor ,

Another embodiment of the invention is dedicated to the integration of the spring element in the pliers head. For this embodiment, it is proposed that the spring element (at least partially) extends in the circumferential direction about a Gesenkachse. This can happen extend the spring element with a circumferential direction of, for example, more than 90 °, more than 180 ° or even more than 270 ° about the Gesenkachse. It is possible that the spring element extends with a plurality of rectilinear, mutually inclined portions in the circumferential direction. But is also possible any curved course of the spring element in the circumferential direction.

In a preferred embodiment, the spring element is designed as circular arc spring or coil spring. For such a circular-arc spring or coil spring results in a particularly favorable characteristic of the spring element, under certain circumstances, large spring travel are possible. It is also possible that on such a spring element an elasticity is brought about, which acts both in the circumferential direction about the Gesenkachse and in the radial direction to the Gesenkachse, which may be advantageous for the integration of the spring element in the power flow between the drive elements, the drive mechanism and the actuators or dies.

In the embodiment of the spring element as a bending beam, the course of the flexural rigidity over the longitudinal axis of the bending beam can be arbitrary. In a preferred embodiment of the invention, the bending beam has a bending stiffness varying in the direction of its (straight or curved longitudinal axis).

For a particular embodiment of the crimping tool, the area moment of inertia of the bending beam increases from the spring base point, which is acted on by the drive mechanism, to a circumferential cross-section of the bending beam opposite that spring base, which increase can be continuous or in steps.

In a further embodiment of the pressing tongs according to the invention, the area moment of inertia of the bending beam is symmetrical to an axis of symmetry. The axis of symmetry runs approximately or exactly through the spring base on which the action by the drive mechanism takes place, and the cross section of the bending beam, which is opposite to this spring base in the circumferential direction. In this case, the die axis is preferably located on the said axis of symmetry. Such a configuration has proved to be particularly favorable for the design of the stresses in the bending beam and / or a symmetrical force generation on the coupled to the bending beam actuator.

As explained above, the dies can be fastened directly to an actuating element. For another embodiment of the invention, an actuator on guides for dies. The other actuator has actuating surfaces for the dies. In this case, relative movement of the actuators results in movement of the dies relative to the guides caused by the contact of the actuation surfaces with the dies. Preferably, in this context, both a sliding movement of the dies relative to the guides of the one actuating element as well as a sliding and / or rolling movement of the dies relative to the actuating surfaces of the other actuating element.

It is also possible that the actuating elements are pivoted relative to each other about the Gesenkachse, in which case, for example, an actuating element is designed as a pivot ring. In this case, the dies can be mounted pivotably relative to the guides, in particular by means of bearing bolts, which are held on the pliers head and store the dies with pliers head fixed bearing axis. The relative pivoting of the actuators has a pivoting of the dies relative to the guides result. This pivoting of the dies is caused by the contact of the actuating surfaces of the one actuating element with the dies.

While basically any configuration of the drive mechanism is possible, this is preferably designed as a toggle mechanism.

In this case, the end regions of the knee levers facing away from a knee joint of the knee lever mechanism can be mounted on a fixed storage location, for example on a drive element such as a hand lever and / or an actuating element such as a swivel ring. In this case, the effective lengths of the toggle lever and the course of the toggle lever over the working stroke of the toggle mechanism are structurally predetermined.

The invention proposes in a further embodiment, that the toggle mechanism is formed with a roller and a guide part. About the working roller rolls off the roller on the guide part, which may be caused by the closure of the die with the pressing of the workpiece and on the other hand by an elastic deformation of the force-displacement compensating element in the invention, this rolling movement between roller and guide part Shape of the spring element. About the design of the roll diameter, the shape of the curved path of the guide member and the choice of the component and the location at which the roller and the guide member are arranged, a further influence on the characteristics of the drive mechanism can take place.

While in principle guide member and roller can be arranged on any component or on any drive element, the invention also proposes an embodiment in which the guide member is fixed to the drive element, to which an actuating element is attached. By way of example, the drive element to which the guide part is fastened is a hand lever rigidly connected to an actuating element. By contrast, for this embodiment, the roller on the other drive element (in particular on a pivotally hinged to an actuating element hand lever) rotatably mounted. This configuration has the consequence that by means of the rolling of the roller on the guide part, a knee angle of the toggle mechanism can be changed. By a suitable choice of the curved path of the guide part, a knee angle can be predetermined in each case specifically via the working stroke, which meets the requirements. For example, it can be attempted that, regardless of the workpiece to be pressed, the knee angle always remains within an angular range, for example from 130 ° to 180 °, in particular 145 ° to 180 °, due to the rolling movement of the roller relative to the curved path of the guide part.

It is possible that the force ratios of the pressing tongs for the pressing of the workpiece are influenced exclusively by a single spring element, which then forms the force-displacement compensation element. In a further embodiment of the invention it is proposed that a further spring element is provided, which provides a contact force of the roller to the curved path of the guide member, which also includes that a contact force of the roller to the curved path through the further spring element in addition to other the contact pressure supplementary funds.

It is possible here that a spring base of the further spring element acts directly on the spring element, which forms the force-displacement compensating element.

The invention proposes for a further embodiment, that the pressing tongs is formed with a Zwangsgesperre. Under such Zwangsgesperre a locking mechanism is understood, which on the one hand during the passage of the working stroke of the Crimping pliers once reached secures against an opening movement and on the other hand, the opening movement of the crimping pliers allows only when the working stroke of the crimping pliers is completely traversed. With the use of a Zwangsgesperres process reliability can be increased by, on the one hand during the power stroke encompassing the pressing tongs with a temporary relief of the hand lever is possible with securing this Teilpressstufe by Zwangsgesperre. On the other hand, it can be avoided that the pressing tongs are opened again and the workpiece is removed from the pressing tongs before the working stroke has been completed, and thus before a proper pressing of the workpiece has taken place.

In a further embodiment, the invention proposes that the Zwangsgesperre is formed with a Sperrverzahnungshebel. The ratchet lever is rotatably supported about the axis of rotation of the roller. Off the axis of rotation of the pawl lever this forms two lever parts. An outer end region of a lever part forms the locking teeth of the Zwangsgesperres. The outer end portion of the other lever member is connected via a slot with the drive element to which the guide member is attached. About this slot, which may have any contour, despite the coupling of the axis of rotation of the pawl lever on the roller and the guide member with the drive element allows an articulation of the slot equipped end portion of the pawl lever on this drive element.

In principle, the pressing tongs can also be used exclusively for a type, a geometry and / or a cross-sectional area of the workpiece. In a preferred embodiment of the invention are with the pressing tongs using the force-displacement compensation as a result of the force-displacement compensating element and / or using the movement of the roller along the curved path with a change in the size and angular relationships of the toggle mechanism workpieces with different Pressed to be pressed cross-sectional areas. Here, the cross-sectional areas of the different workpieces which can be pressed with the same pressing tongs (without replacement of a replaceable head or replacement of dies), at least by a factor of 30 (in particular at least by a factor of 45, 50, 75, 100, 115 or even 200) from each other differ. By way of example only, workpieces having a cross-sectional area of 0.08 mm ² , 0.14 mm ² , 0.25 mm ² , 0.35 mm ² , 0.5 mm ² , 0.75 mm can be produced with the same crimping pliers ² , 1.0 mm ² , 1.5 mm ² , 2.5 mm ² , 4 mm ² , 6 mm ² , 10 mm ² and 16 mm ^{2 are} pressed.

In the open position of the pressing tongs form the dies a receptacle for the workpiece, which must be at least as large as the largest with the pressing tongs to be pressed workpiece. The smaller the workpiece that is inserted into the receptacle formed by the dies in the open position, then in fact, the greater the clearance and the worse is the guidance and fixation of the workpiece in the pliers head in the open position. In order to ensure a recording and exact alignment of the smaller workpiece in the pressing tongs before the start of the actual pressing operation, a partial closing movement would have to be brought about and fixation of the drive elements carried out in such a way that the receptacle formed by the dies is reduced to such an extent that the smaller workpiece fits precisely is included. The invention proposes alternatively or cumulatively that a positioning device can be arranged on the pliers head, by means of which a workpiece with a predetermined cross-sectional area in a receptacle (preferably also workpieces of different cross-sectional area in several receptacles) in a predetermined position and orientation on the Pliers head can be kept. In this case, the positioning device is preferably equipped only with suitable receptacles for a subset of the workpieces and cross-sectional areas to be pressed by the pressing tongs.

For a particular proposal of the invention it is proposed that the spring element is guided over a guide. This guide is preferably designed as an additional guide to other couplings of the spring element with the adjacent components of the pressing pliers, ie in particular in addition to the drive connection of the spring element with the actuating element and in addition to the coupling of the spring element in the region of the other Federfußpunktes with the drive element or lever. In this case, the additional guidance can be effected in the region of a spring base point or at any location of the spring element between the spring base points. The guide may be permanent or only temporary during part of the power stroke. By means of the guide, a guidance of the spring element in the circumferential direction about the Gesenkachse and / or radially to the Gesenkachse. It is also possible that in the guide, the spring element is acted upon by a bias against a projection or paragraph or in an end position. Only with overcoming the bias for passing through a portion of the power stroke of the pressing tongs can be done a solution of the spring element and thus a movement along the guide. For this embodiment, the spring element can be equipped with a targeted "nonlinearity", since with the solution of the spring element of the Projection or paragraph change the boundary conditions for the elastic deformation of the spring element. Here, the guide can be done for example by a housing or a cover plate of the pliers head. It is also entirely possible, however, for the guide of the spring element to be effected by a component of the pressing tongs moving in the course of the working stroke. About a particular embodiment of the invention, the leadership of a region of the spring element relative to another region of the spring element is effected.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are merely exemplary and can take effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Without thereby altering the subject matter of the appended claims, as regards the disclosure of the original application documents and the patent, further features can be found in the drawings, in particular the illustrated geometries and the relative dimensions of several components and their relative arrangement and operative connection. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

The features mentioned in the patent claims and the description are to be understood in terms of their number that exactly this number or a greater number than the said number is present, without requiring an explicit use of the adverb "at least". For example, when talking about an element, it should be understood that there is exactly one element, two elements or more elements. These features may be supplemented by other features or be the only characteristics that make up the product in question.

The reference numerals contained in the claims do not limit the scope of the objects protected by the claims. They are for the sole purpose of making the claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 bis 11

zeigen eine erste Ausführungsform der Presszange mit einer Öffnungsstellung (Fig. 1), einer Schließstellung (Fig. 2), Bestandteilen der Presszange in Explosionsdarstellung (Fig. 3 und 4), einem Führungsteil mit Kurvenbahnen in räumlicher Einzelteilzeichnung (Fig. 5), dem Kniewinkel der Presszange in Öffnungsstellung (Fig. 6) und Schließstellung (Fig. 7) sowie den Betätigungskraftverläufen für unterschiedliche Werkstücke (Fig. 8) und den Abmessungen des Federelements (Fig. 9 und 10) sowie den sich ergebenen Spannungsverläufen in dem Federelement (Fig. 11).

Fig. 12 bis 13

zeigen eine weitere Ausführungsform der Presszange, wobei Fig. 12 den Kniewinkel des Kniehebelmechanismus in der Öffnungsstellung und Fig. 13 den Kniewinkel des Kniehebelmechanismus in der Schließstellung zeigt.

Fig. 14 bis 22

zeigen weitere Ausführungsformen der Presszange.

Fig. 23 und 24

zeigen eine weitere Ausführungsform der Presszange mit zusätzlicher Führung des Federelements.

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

Fig. 1 to 11

show a first embodiment of the pressing tongs with an open position ( Fig. 1 ), a closed position ( Fig. 2 ), Components of the crimping pliers in exploded view ( Fig. 3 and 4 ), a guide part with curved paths in a spatial part drawing ( Fig. 5 ), the knee angle of the pressing tongs in the open position ( Fig. 6 ) and closed position ( Fig. 7 ) and the Betätigungskraftverläufen for different workpieces ( Fig. 8 ) and the dimensions of the spring element ( Fig. 9 and 10 ) as well as the resulting voltage curves in the spring element ( Fig. 11 ).

Fig. 12 to 13

show a further embodiment of the pressing tongs, wherein Fig. 12 the knee angle of the toggle mechanism in the open position and Fig. 13 shows the knee angle of the toggle mechanism in the closed position.

FIGS. 14 to 22

show further embodiments of the pressing tongs.

FIGS. 23 and 24

show a further embodiment of the pressing tongs with additional guidance of the spring element.

DESCRIPTION OF THE FIGURES

Fig. 1 shows a crimping pliers 1 in a representation in which one of two cover plates 2a, 2b, with which a solid hand lever 3 and a pliers head 4, in particular a kind of "housing" of the pliers head 4, is disassembled.

The pressing tongs 1 is formed with a fixed hand lever 3 and a movable hand lever 5. A pivoting of the hand lever 3, 5 towards each other (see transition from Fig. 1 to Fig. 2 ) via a drive mechanism 6 and a spring element 7, which forms a force-displacement compensating element 8, a relative movement of actuators 9, 10. Here, the actuator 9 is integral with the part of the cover plate 2, which extends in the region of the pliers head 4 formed so that it is a fixed actuator 9 here. By contrast, the actuating element 10 is designed as a movable actuating element 10 in the form of a pivot ring 11, which relative to the fixed actuating element 9 to the vertical to the plane according to Fig. 1 oriented, given by dies 12 workpiece and die axis 13 is pivotable. The dies 12 are pivotable about axes, which are oriented parallel to the Gesenkachse 13, mounted opposite bearing pins 14, which are held on the actuating element 9 and the cover plate 2. The pivot pin 11 thus forms guides 15 for the dies 12. The pivot ring 11 forms radially inwardly in the region of grooves actuating surfaces 16 on which abutment surfaces 17 of the dies 12 abut such that a pivoting of the pivot ring 11 about the Gesenkachse 13 pivoting the dies 12 has around the bearing pin 14 result. This pivoting of the dies 12 in turn has the consequence that a die contour 18 formed by the dies 12, which is closed in the circumferential direction about the die axis 13 with the formation of minimal gaps between the adjacent dies 12, changes in size. For the illustrated embodiment, the die contour 18 is formed hexagonal regardless of the size thereof in the first approximation.

The spring element 7 is formed by an integral projection of the swivel ring 11, which extends in a circular arc or here in a spiral around the swage axis 13 in the circumferential direction. For the illustrated embodiment, the circumferential angle is approximately 360 °, wherein the formed in the connection region with the pivot ring 11 Federfußpunkt 19 and the outer Federfußpunkt 20 of the spring element 7 approximately in a 4:00 clock position with respect to the Gesenkachse 13 as shown in FIG Fig. 1 are arranged with horizontally oriented fixed lever 3. The Federfußpunkt 20 is pivotable, here via a bearing pin 21, hinged to the movable hand lever 5. On the movable hand lever 5, here via a bearing pin 22, a roller 23 is rotatably mounted. The roller 23 abuts on a cam track 24 of a guide member 25. In the present case, the guide member 25 performs the roller 23 only on one side about the cam track 24, while for a different embodiment Also, a recording of the roller 23 between two curved paths can be done, which can be the case with a game or without play. The guide member 25 is rigid, here via bearing pins 26, 27, fixed to the fixed hand lever 3. Opposite the bearing pin 22 is also pivotally mounted a Sperrverzahnungsheben 28, which is formed with lifting parts 29, 30. In the outer end region, the lever part 29 forms a locking toothing 31. The lever member 30 has a radially oriented to the bearing pin 22 slot 32 through which the bearing pin 27 passes.

The drive mechanism 6 is designed as a toggle mechanism 33. This has a toggle lever 34, which corresponds to the connection between the contact point of the roller 23 with the guide track 24, and a second toggle 35, which corresponds to the connection between the bearing pins 21, 22 predetermined bearing axes. Between the toggle levers 34, 35 a knee angle 36 is formed.

For the working stroke of the pressing tongs 1 from the open position according to Fig. 1 according to the closed position Fig. 2 leads for disappearing pressing forces in a first partial stroke, the movement of the hand lever 3, 5 in support of the roller 23 on the curved path 24 of the guide member 25 to the fact that the bearing pin 21 and thus also the Federfußpunkt 20 of the spring element 7 in the circumferential direction 37 about the Gesenkachse 13th move. As a result of the vanishing pressing forces no elastic deformation of the spring element 7, so that a corresponding pivoting of the pivot ring 19 takes place, which in turn the pivoting of the dies 12 is connected and a reduction of the cross-sectional area of the die contour 18 is accompanied. However, since the point of contact of the roller 23 with the cam track 24 of the guide member 25 is not fixed, the roller 23 can roll on the cam track 24 during this partial stroke, which depending on the rolling motion of the roller 23 and the geometry of the cam track 24 also changed a knee angle 36 sets. This already complex kinematics is superimposed on an increasing elastic deformation of the spring element 7 with increase of the pressing forces in the region of the die with increasing closing movement. This is to be clarified on the basis of a theoretical limiting case, for which it is assumed that the workpiece after a first partial stroke, which is designed for example as idle stroke, and a second partial stroke, by means of which a pressing of the workpiece with plastic deformation thereof, during the last third Teilhubs is ideal rigid. Upon reaching this ideal rigid state of the workpiece, the position of the dies 12 and the pivot ring 11 and thus also of the spring base point 19 also fixed. Nevertheless, in the third partial stroke, a further closing movement of the hand lever 3, 5 take place, since with further loading of the hand lever 3, 5, the spring element 7 can be elastically deformed. On the one hand, a deformation of the spring base point 20 in the circumferential direction 37 can take place. It is also possible that the spring base point 20 is deformed in the radial direction 38 to the Gesenkachse 13. Thus, despite a rigid workpiece and fixed dies 12, fixed pivot ring 11 and fixed spring base 19 a rolling movement of the roller 23 along the guideway 24 done with transfer of the hand lever 3, 5 in the closed position. For realistic stiffnesses of the workpiece results in a superposition of a plastic deformation of the workpiece, but which becomes smaller and smaller with increasing pressing force, with an elastic deformation of the spring element 7, the proportion to the plastic deformation of the workpiece with increasing pressing force is always greater. This results in practice u. U. a superposition of the second partial stroke with the third partial stroke.

• Für ein großes Werkstück ist ein Leerhub als erster Teilhub (bspw. zwischen 0% und 15% des Arbeitshubs) sehr kurz ausgebildet und es erfolgt eine plastische Verformung des Werkstücks in einem zweiten Teilhub bspw. bereits am Anfang des Arbeitshubs (bspw. zwischen 15% und 60% des Arbeitshubs), während sich ein großer dritter Teilhub (bspw. zwischen 60% und 100% des Arbeitshubs) anschließt, in welchem vorrangig die Verformung des Federelements 7 erfolgt.
• Für ein kleineres Werkstück ist ein Leerhub als erster Teilhub (bspw. zwischen 0% und 30% des Arbeitshubs) länger ausgebildet und es erfolgt eine plastische Verformung des Werkstücks in einem zweiten Teilhub in einem späteren Bereich des Arbeitshubs (bspw. zwischen 30% und 80% des Arbeitshubs), während sich ein kleiner dritter Teilhub (bspw. zwischen 80% und 100% des Arbeitshubs) oder sogar kein dritter Teilhub anschließt, in welchem vorrangig die Verformung des Federelements 7 erfolgt.

Depending on the cross-sectional area of the workpiece to be pressed, the position of the different partial strokes changes over the working stroke of the pressing tongs 1:

• For a large workpiece, an idle stroke as a first partial stroke (eg. Between 0% and 15% of the working stroke) is very short and there is a plastic deformation of the workpiece in a second partial stroke, for example. Already at the beginning of the working stroke (eg. Between 15% and 60% of the working stroke), while a large third partial stroke (for example between 60% and 100% of the working stroke) follows, in which the deformation of the spring element 7 takes place with priority.
• For a smaller workpiece an idle stroke as a first partial stroke (eg. Between 0% and 30% of the working stroke) is formed longer and there is a plastic deformation of the workpiece in a second partial stroke in a later range of the power stroke (eg. Between 30% and 80 % of the working stroke), while a small third partial stroke (for example between 80% and 100% of the working stroke) or even no third partial stroke follows, in which the deformation of the spring element 7 takes place with priority.

With the pivoting of the hand lever 3, 5 toward each other, a pivoting of the locking toothed lever 28 is accompanied, during which a locking lug 39 of a pawl 40, which is under the action of a spring 93 also pivotable on the hand lever. 5 is stored, ratchet-like along the locking teeth 31 slides. If the hand forces applied to the hand levers 3, 5 are temporarily reduced or eliminated, the engagement of the locking nose 39 in the locking toothing 31 blocks the opening movement of the hand levers 3, 5 and thus also the opening movement of the dies 12. Only when the hand levers 3, 5 completely close Have reached closed position, the locking lug 39, the pawl 31 has completed, so that the pawl 40 can fold down and ratchet-like slide during a then possible opening movement of the hand lever 3, 5 on the ratchet 31 back to their original position. With the Sperrverzahnungshebel 28 and acted upon by the spring 93 pawl 40 Zwangsgesperre 48 is formed.

With regard to the basic design of a pressing tongs 1 with a pivot ring 11 and the possibility of joint pivoting of six dies 12 here by relative rotation of the actuators 9, 10 is based on the relevant prior art, in particular EP 0 732 779 B1 and DE 10 140 270 B4 and DE 10 2005 003 615 B3 directed. In the present case, the hand lever 3, 5 drive elements 41, 42, on which the manual actuating forces are exerted. It is understood that the drive elements 41, 42 can also be acted upon by forces of an actuator such as an electric drive.

The spring element 7 is formed here as a kind of bending beam 43. In the region of the spring base point 20, force components in the circumferential direction 37 and / or in the radial direction 38 are introduced into this bending beam 43, which stresses the bending beam 43 about a bending axis which is vertical to the plane of the drawing Fig. 1 is oriented. It is also possible in principle to use a stress of the bending beam 43 with a compressive force on buckling. Preferably, however, the bending beam 43 is subjected to a tensile force in the circumferential direction 37. For the illustrated embodiment, the bending beam 43 is in accordance with a in the drawing plane Fig. 1 extending spiral spring or circular arc spring 44 is formed. Here, the spiral or circular arc spring extends in the circumferential direction 37 about the Gesenkachse 13.

The bending beam 43 in this case has a circular arc-shaped or spiral-shaped neutral fiber or longitudinal axis 45, along which the bending stiffness changes, in particular by a change in the area moment of inertia. For the illustrated embodiment, the design of the height of the cross section of the bending beam 43, which is the area moment of inertia determined, symmetrical to an axis of symmetry, which passes through the Gesenkachse 13 and the Federfußpunkt 20. Accordingly, the height and the cross-sectional area of the spring element 7 is maximally in a cross-section 47, which is arranged centrally between the spring base points 19, 20 in the circumferential direction.

In the exploded view according to Fig. 3 it can be seen that the pressing tongs with two cover plates 2a, 2b is formed. The two cover plates 2a, 2b on the one hand form the fixed hand lever 3. On the other hand, the cover plates 2a, 2b form a kind of housing of the pliers head 4, between which the moving parts, namely the spring element 7, the pivot ring 11 and the dies 12 are accommodated. On the other hand, the bearing pins 14 of the dies 12 are received in bores 49 of the cover plates 2a, 2b.

It can be seen further in Fig. 3 in that the spring element 7 and the swivel ring 11 are formed in plate construction, here with four plates, wherein the individual plates for the swivel ring 11 and the spring element 7 are formed in one piece.

Notwithstanding the in Fig. 1 and 2 illustrated embodiment has according to Fig. 3 optionally, the spring element on its outer side a projection 50 in which a spring base 51 or a coupled with such a Federfußpunkt tappet another spring 52 is supported, the other Federfußpunkt 53 is supported on the cover plates 2a, 2b or the movable hand lever 5. By way of the further spring 52, the force relationships on the pressing tongs 1 can be influenced in addition to the spring element 7. Thus, the additional spring 52 can serve to influence the dependence of the generated pressing force on the pivoting angle of the hand lever and the actuating force applied to the hand lever. It is also possible that the contact pressure of the roller 23 on the guide track 24 of the guide member 25 is increased or ensured by the further spring 52.

Fig. 4 shows the assembled basic components of the pressing tongs 1 according to Fig. 3 before its assembly with the two hand levers 3, 5 associated with handles 54, 55th

According to Fig. 3 and 4 the pressing tongs 1 can have a positioning device 56. The positioning device 56 has three alternative receptacles 57a, 57b, 57c for workpieces with different cross-sectional areas for the illustrated embodiment. The positioning device 56 can be brought into different operating positions, in which in each case a receptacle 57 a (57 b, 57 c) is arranged coaxially to the die axis 13. For the illustrated embodiment, the positioning device 56 is formed with a Positionierstrebe or positioning washer 58 which is pivotally mounted on the cover plates 2, here by means of a bearing pin 59. The Positionierstrebe or positioning washer 58 lies directly sliding on the outside of the cover plate 2b.

As in Fig. 5 is shown, the guide member 25 may be fork-shaped with the formation of a slot 60 between two legs 61a, 61b. Through the slot 60 of the guide member 25 extends to allow a relative pivotal movement of the locking teeth 28 (see also Fig. 3 ). In the outer end region, the legs 61a, 61b each have a bore 62a, 62b, through which the bearing pin 27 extends in the installed state. For reasons of weight, the legs 61 a, 61 b have recesses 63.

In Fig. 5 It can be seen that for the illustrated embodiment, two parallel cam tracks 24a, 24b are formed by the two legs 61a, 61b, at which then two rollers 23a, 23b roll on both sides of the locking gear lever 28. Furthermore, it can be seen that the cam tracks 24a, 24b for the illustrated embodiment have two concave portions 64, 65, between which a convex portion 66 is disposed. Here, the curved path 24 in the concave portion 65, which is traversed at the beginning of the power stroke, more inclined than other portions of the curved path 24th

• geeignete Formgebung der Kurvenbahn 24,
• Wahl der Kennlinie und Geometrie des Federelements sowie
• Auslegung des Antriebsmechanismus 6

der Kniewinkel 36 während des gesamten Arbeitshubs immer zwischen 130° und dem Streckwinkel von 180°.By suitable shaping of the cam track 24 it can be achieved that the knee angle 36 of the toggle mechanism 33 is relatively large during the entire working stroke. According to Fig. 6 the knee angle 36 is already at the beginning of the working stroke about 135 °, while this according to Fig. 7 at the end of the working stroke in the range of 160 to 185 °. Preferably lies through

• suitable shaping of the curved path 24,
• Choice of the characteristic and geometry of the spring element as well
• Design of the drive mechanism 6

the knee angle 36 always during the entire working stroke between 130 ° and the draft angle of 180 °.

In Fig. 8 the applied hand forces 67 are shown as a function of the actuation path 68 of the movable hand lever 5. Here, the curves 69 to 81 show the hand force curves for different cross sections of the workpieces, namely 0.08 mm ² (69), 0.14 mm ² (70), 0.25 mm ² (71), 0.35 mm ² (72 ), 0.5 mm ² (73), 0.75 mm ² (74), 1.0 mm ² (75), 1.5 mm ² (76) 2.5 mm ² (77), 4 mm ² ( 78), 6 mm ² (79), 10 mm ² (80) and 16 mm (81). It can be seen here that, for smaller workpieces, the initial first partial stroke is first passed through with vanishing pressing forces, whereas the actual manual forces do not have to be applied until the end of the working stroke. As the size of the workpiece increases, the slope of the curves 69-81 is further displaced toward smaller actuation paths. It can be seen in Fig. 8 in that pressing of all of said workpieces with the same pressing tongs 1 is possible under controllable manual forces, which are preferably smaller than 300 N.

In Fig. 9 is shown for the spring element 7 an exemplary choice of dimensions. It can be seen here that the spring element extends in a spiral shape around the die axis 13 with a circumferential angle of approximately 360 °. The effective height 82 of the spring element 7 for influencing the area moment of inertia is symmetrical to the axis of symmetry 46 and increases from both Federfußpunkten 19, 20 to the same extent to the middle of the spring element 7 in the circumferential direction between the two Federfußpunkten 19, 20. While in Fig. 9 only discrete values of the height 82 of the spring element 7 are indicated, shows Fig. 10 the dependence of the height 82 from the circumferential angle 83, starting from the point centrally between the two spring base points 19, 20th

Figure 11 shows the stress distribution in the spring element 7, wherein the same gray levels are used for equal voltages here. By means of the symmetrical design of the spring element 7 and the choice of heights 82 according to Fig. 10 can be achieved that the maximum stresses in the spring element 7 along the circumference or the longitudinal axis 45 are constant.

For the embodiment according to Fig. 12 and 13 the toggle mechanism 33 is not formed with a roller 23 and a cam track 24 of a guide member 25. Rather, here (in the embodiment of the toggle lever 35 according to the previously described embodiment) of the knee lever 34 is formed by a pressure lever 83 which forms the knee joint 84 in the region of the bearing pin 22 and in an end region via a bearing pin 27 on the Cover plate 2 is hinged. In the other end region of the pressure lever 83 directly forms the locking teeth 31 of the Zwangsgesperres 48. As a result of the use of the pressure lever 83 instead of the principle of roller 23 / cam track 24 is in the open position according to Fig. 12 the knee angle 36 about 90 °, which starting from the open position not immediately large pressing forces can be generated while in the closed position according to Fig. 13 a knee angle 36 of about 160, 165 or 170 ° is reached, for which thus high pressing forces can be generated at the end of the power stroke. Between the open position and the closed position, the knee angle 36 increases continuously with the passage of the power stroke (while for the use of the principle roller 23 / curved path 24 in accordance with Fig. 1 to 11 depending on the selected contour of the curved path 24 is quite possible that the knee angle 24 is smaller during the passage of the power stroke in at least a portion or remains constant). This makes it clear that the use of the principle of roller 23 / cam track 24 with a suitable design of the cam track 24 is advantageous if, depending on the size of the workpiece to be pressed, the actual pressing should take place at the beginning of the working stroke or at the end of the working stroke. Nevertheless, the design according to the invention can also be used for use with pressing tongs without the principle of roller 23 / curved track 24.

Fig. 14 shows a further embodiment of a pressing tongs 1, wherein according to the embodiment, in Fig. 12 and 13 is shown, a pressure lever 83 without roller / cam track is used. However, here extends the spring element 7, which is also formed as a spiral or circular arc spring 44, between the spring base points 19, 20 not with a circumferential angle of about 360 ° about the Gesenkachse 13, but only with a circumferential angle of about 240 °, without thereby leaving the basic principle according to the invention.

Fig. 15 shows a further embodiment in which a circular arc spring 44 extends between the spring base points 19, 20 only over a circumferential angle of approximately 90 °. Furthermore, the circular arc spring 44 is not oriented here exclusively in the circumferential direction about the Gesenkachse 13, which under certain circumstances results in a modified type of stress of the circular arc spring 44. Put simply, in this case, the circular arc spring 44 can be understood as a curved resilient "strut", which acts tangentially on the pivot ring 11.

For the in Fig. 16 illustrated embodiment, the spring element 7 and the spiral or circular arc spring 44 extends over a circumferential angle of about 180 °. Also here instead of the principle of roller 23 / curved track 24, an embodiment with pressure lever 83 insert. However, here the pressure lever 83 is not rigid, but deliberately yielding, so that this embodiment integrates the measures according to the non-prepublished European patent application EP 14 154 206.8 into the pressing tongs. Also in this case, the pressure lever 83 forms the locking teeth 31 in one end region. Between the knee joint 84 and the articulation of the pressure lever 83 on the cover plates 2, the pressure lever is formed in a rough approximation V-shaped or curved or arcuate formed with a bow angle in the range of 150 to 180 °.

Fig. 17 shows a further embodiment of the pressing tongs 1 according to the invention with a pressure lever 83 which is formed here without locking teeth 31 and has a greater extent in direct articulation of the pressure lever 83 to the two hand lever 3, 5th

The embodiment according to Fig. 18 basically corresponds to the embodiment according to Fig. 12 , However, here is another transfer of the movement of the actuating element 10 or pivot ring 11 on the dies 12: In this case, only two opposing dies 12a, 12b are present. The dies 12a, 12b are also guided here by guides 15, wherein the guide is not carried out for a pivoting movement of the dies 12a, 12b, but for a translational movement of the dies 12a, 12b towards and away from each other. A cause of the movement of the dies 12a, 12b along the predetermined by the guides 15 degrees of freedom is also effected here by a contact of actuating surfaces 16 of the pivot ring 11 with counter-actuating surfaces 17 of the dies 12a, 12b. While in Fig. 18 the pressing tongs 1 is shown in an open position, shows Fig. 19 the closed position of the pressing tongs. 1

For the in Fig. 20 illustrated embodiment is between the hand lever 3, 5 and the actuators 9, 10 no drive mechanism 6, in particular no toggle mechanism 33, interposed. Rather, the hand lever 3 is rigidly connected directly to the actuating element 9, while the actuating lever 5 is directly and rigidly connected to the Federfußpunkt 20 of the spring element 7. The other spring base point 19 is directly and rigidly connected to the actuating element 10, here the pivot ring 11. Further shows Fig. 20 in principle, the use of the measures according to the invention for a pressing tongs 1, in which the dies do not form a substantially closed in the circumferential direction die contour 18. Rather, here is the introduction of notches in the workpiece via dies 12, which are formed here in the manner of thorns 85. Again, the mandrels 85 are guided by guides 15, in which case the guides 15, the mandrels 85 also translationally in the radial direction. In this case, the pivot ring 11 forms guide grooves 86, which are inclined with respect to the circumferential direction. In these guide grooves 86 of the mandrel 85 engages with a pin. As a result of this coupling, the pivoting of the pivot ring 11 leads to a movement of the mandrels 85 radially inwardly, which is associated with the pressing of the workpiece.

Fig. 21 shows an embodiment of a pressing tongs 1 without the use of a toggle mechanism 33. Rather, here is the movable hand lever 5 pivotally mounted directly on the cover plate 2 and thus the fixed hand lever 3. The Federfußpunkt 20 of the spring element 7 is articulated directly to an over the pivot point of the hand lever 5 on the hand lever 3 protruding end portion of the hand lever 5, which takes place here via a bearing pin 87 of the spring element 7, which is received in a slot 88 of the hand lever 5.

Fig. 22 shows a further embodiment of the pressing tongs 1, which basically in the Fig. 1 to 11 illustrated embodiment corresponds. However, here the contour of the guideway 24 is selected such that it has exclusively concave portion 64, 65, which are connected to each other via a rectilinear portion 89.

Fig. 23 and 24 show a further embodiment of a pressing tongs, wherein Fig. 23 the pressing tongs in the open position with mounted cover plate shows and Fig. 24 the pressing tongs also in the open position, but without mounted cover plate shows. This embodiment basically corresponds to the embodiment of the pressing tongs 1 according to FIG Fig. 1 to 11 or Fig. 22 , However, the spring element 7 is guided with an additional guide 90. For the illustrated embodiment, the guide is in the region of the spring base point 20. The guide 90 is formed by a spring pin 7 supported by the guide pin 91 which is guided in a guide groove or a slot 92 of the cover plates 2. Preferably, the slot 92 extends circumferentially around the die axis 13.

For the illustrated embodiments, the guide member 25 is fixed to the fixed hand lever 3, while the roller 23 is rotatably supported relative to the movable hand lever 5. But it is also possible that the guide member 25 is fixed to the movable hand lever 5, while the roller 23 is rotatably mounted relative to the fixed hand lever 3.

It is possible that for a hand-operated pressing tongs and a power-operated pressing tongs in the invention, the same basic structure is used, being then used in the manually operated pressing tongs as drive elements hand lever, while for the power-operated pressing tongs instead of the hand lever to an actuator deflected drive elements are used. To give just a simple non-limiting example, for an externally operated crimping tool, the fixed (hand) lever may also be shortened and supported on a fixed abutment, while on the movable (also shorter) (hand) Lever a connecting rod, a plunger o. Ä. Of the actuator is articulated. UU is a power-operated crimping pliers trained without Zwangsgesperre.

LIST OF REFERENCE NUMBERS

1

crimping pliers

2

cover plate

3

solid hand lever

4

pliers head

5

movable hand lever

6

drive mechanism

7

spring element

8th

Force-compensation element

9

fixed actuator

10

movable actuator

11

swivel

12

die

13

die axis

14

bearing bolt

15

guide

16

actuating surface

17

Counter-actuating surfaces

18

Gesenkkontur

19

spring base

20

spring base

21

bearing bolt

22

bearing bolt

23

role

24

cam track

25

guide part

26

bearing bolt

27

bearing bolt

28

Lock gear lever

29

lever part

30

lever part

31

locking teeth

32

Long hole

33

Toggle mechanism

34

toggle

35

toggle

36

knee angle

37

circumferentially

38

radial direction

39

locking tab

40

lock blade

41

driving element

42

driving element

43

bending beam

44

Spiral or circular arc spring

45

longitudinal axis

46

axis of symmetry

47

cross-section

48

Zwangsgesperre

49

drilling

50

head Start

51

Spring base point

52

another spring

53

Spring base point

54

handle

55

handle

56

positioning

57

admission

58

positioning bar

59

bearing bolt

60

slot

61

leg

62

drilling

63

recess

64

concave sub-area curved track

65

concave sub-area curved track

66

convex part of the curved path

67

manual force

68

actuating

69

Curve

70

Curve

71

Curve

72

Curve

73

Curve

74

Curve

75

Curve

76

Curve

77

Curve

78

Curve

79

Curve

80

Curve

81

Curve

82

height

83

pressure lever

84

knee

85

mandrel

86

guide

87

bearing bolt

88

Long hole

89

rectilinear section

90

guide

91

guide pin

92

Long hole

93

feather

Claims (22)

Pressing tongs (1) for pressing a workpiece with a) two drive elements (41, 42), b) a pliers head (4), c) two in the region of the pliers head (4) arranged actuating elements (9, 10) which actuate dies (12), between which the workpiece can be pressed, and d) a spring element (7), which da) is arranged in the power flow between the drive elements (41, 42) and the dies (12) and db) forms a force-displacement compensating element (8), characterized in that e) the force-displacement compensating element (8) forming the spring element (7) in the region of the pliers head (4) is arranged. Crimping pliers (1) according to claim 1, characterized in that a) a drive mechanism (6) is present, which between the drive elements (41, 42) and the actuating elements (9, 10) is interposed, and b) the spring element (7) in the power flow between the drive mechanism (6) and the actuating elements (9, 10) is interposed. Crimping pliers (1) according to claim 1 or 2, characterized in that a spring base point (19) of the spring element (7) on one of the actuating elements (10) is fixed. Crimping pliers (1) according to one of the preceding claims, characterized in that the spring element (7) is designed as a bending beam (43). Crimping pliers (1) according to claim 4, characterized in that the spring element (7) is formed in plate construction. Crimping pliers (1) according to one of the preceding claims, characterized in that the spring element (7) extends in the circumferential direction about a Gesenkachse (13). Crimping pliers (1) according to claim 6, characterized in that the spring element (7) as a circular arc spring or coil spring (44) is formed. Crimping pliers (1) according to one of claims 4 to 7, characterized in that the bending beam (43) has a bending stiffness varying in the direction of its longitudinal axis (45). Crimping tool according to claim 8, characterized in that the area moment of inertia of the bending beam (43) from the spring base point (20), which is acted upon by the drive mechanism (6), to a this spring base in the circumferential direction opposite cross-section (46) of the bending beam (43 ) increases. Crimping pliers according to claim 9, characterized in that the area moment of inertia of the bending beam (43) is symmetrical about an axis of symmetry (46) which is approximately through the spring base point (20), which is acted upon by the drive mechanism, and this spring base (20 ) in the circumferential direction opposite cross section (47) of the bending beam (43). Crimping pliers (1) according to one of the preceding claims, characterized in that a) an actuating element (9) has guides (15) for dies (12) and b) an actuating element (10) has actuating surfaces (16) for the dies (12), c) wherein a relative movement of the actuating elements (9, 10), a movement of the dies (12) relative to the guides (15) result, which is caused by the contact of the actuating surfaces (16) with the dies (12). Crimping pliers (1) according to one of the preceding claims, characterized in that a) the actuating elements (9, 10) are pivoted relative to each other about the Gesenkachse (13), b) the dies (12) are mounted pivotably relative to the guides (15) and c) the relative pivoting of the actuating elements (9, 10) has a pivoting of the dies (12) relative to the guides (15) result, which is caused by the contact of the actuating surfaces (16) with the dies (12). Crimping pliers (1) according to one of the preceding claims, characterized in that the drive mechanism (6) is formed with a toggle mechanism (33). Crimping pliers (1) according to claim 13, characterized in that the toggle mechanism (33) is formed with a roller (23) and a guide part (25), wherein the roller (23) rolls over the working stroke on the guide part (25). Crimping pliers (1) according to claim 14, characterized in that a) the guide part (25) on a drive element (41) is fixed, on which an actuating element (9) is fixed, and b) the roller (23) on the other drive element (42) on which with the other actuating element (10) connected spring element (7) is articulated, is rotatably mounted. Crimping pliers (1) according to claim 14 or 15, characterized in that a further spring element (52) is present, which provides a pressing force of the roller (23) on the guide part (25). Crimping pliers (1) according to claim 16, characterized in that a spring base point of the further spring element (52) acts on the spring element (7). Crimping pliers (1) according to one of the preceding claims, characterized in that a Zwangsgesperre (48) is present. Crimping pliers according to claim 18, characterized in that the Zwangsgesperre (48) is formed with a Sperrverzahnungshebel (28), a) which is rotatably mounted about the axis of rotation of the roller (23) and b) of which one of the locking teeth (31) opposite end portion via a slot (32) with the drive element (41) is connected to which the guide member (25) is attached. Crimping pliers (1) according to one of the preceding claims, characterized in that they are in use with the crimping pliers (1) a) the force-displacement compensation as a result of the force-displacement compensating element (8) and / or b) the movement of the roller (23) along the cam track (24) of the guide member (25) with a change in the size and angular relationships of the toggle mechanism (33) Workpieces with different cross-sectional areas to be pressed can be pressed, wherein the cross-sectional areas deviate from one another by at least a factor of 30 for two different workpieces which can be pressed by the pressing tongs. Crimping pliers (1) according to one of the preceding claims, characterized in that a positioning device (56) for at least one workpiece is arranged on the pliers head (4). Crimping pliers according to one of the preceding claims, characterized in that the spring element (7) via a guide (90) is guided.

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