EP3553899B1 - Crimping tool - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to crimping pliers. The pressing or crimping pliers can be used to manually actuate hand levers to press or crimp a workpiece.

• Kabelschuhe nach DIN 4623,
• Aluminiumverbinder nach DIN 46329
• Aluminium-Presskabelschuhe nach DIN 48201
• Quetschkabelschuhe nach DIN 46234,
• Stiftkabelschuhe nach DIN 46230 oder
• Verbinder, Stecker oder Kabelschuhe für eine Verbindung mit einem Kabel oder Leiter, wie diese in dem Produktkatalog der WEZAG GmbH Werkzeugfabrik "Werkzeuge für die professionelle Anwendung" mit der Veröffentlichungs-Nr. 10/11 beschrieben sind,

Here, crimping pliers are used in particular to establish a permanent mechanical connection and electrical contact. This is preferably done by crimping a plug with a cable or an electrical conductor of any type. Depending on the die profile used, different crimping processes can be carried out with the crimping pliers. For example, it can be a closed crimp, in which the conductor is inserted into a closed crimping zone of a plug or into a closed sleeve and is crimped by plastic deformation of the crimping zone or the sleeve. It is also possible, however, to produce an open crimp in which the plug has an open crimp zone into which the conductor can be inserted from above. To name just a few examples that do not limit the invention, the crimping tool relevant here

• Cable lugs according to DIN 4623,
• Aluminum connector according to DIN 46329
• Aluminum compression cable lugs according to DIN 48201
• Crimp cable lugs according to DIN 46234,
• Pin cable lugs according to DIN 46230 or
• Connectors, plugs or cable lugs for a connection with a cable or conductor, like those in the product catalog of WEZAG GmbH Werkzeugfabrik "Tools for professional use" with the publication no. 10/11 are described,

be crimped. The crimp produced for a closed crimp can be, for example, a hexagonal or hexagonal crimp, a square crimp, a B crimp, a trapezoid crimp, a modified trapezoid crimp, an oval crimp, a mandrel crimp or a two-mandrel crimp. An open crimp can be designed, for example, as a V crimp or B crimp, as a roll crimp or as a double roll crimp.

• zur Ausgestaltung einer gattungsgemäßen Crimpzange,
• zu möglichen Einsatzbereichen der gattungsgemäßen Crimpzange und/oder
• zu unterschiedlichen möglichen Typen von Crimpverbindungen, welche mittels der gattungsgemäßen Crimpzange hergestellt werden können,
  wird auf das Werk
• " Crimptechnik, Herstellung prozesssicherer Verbindungen von elektrischen Leitern und Steckern" der WEZAG GmbH Werkzeugfabrik, Die Bibliothek der Technik 342, Verlag Moderne Industrie, ISBN 978-3-68236-027-7

verwiesen.In addition to establishing the electrical connection between the cable or conductor and plug, a mechanical connection can be established by means of a so-called insulation crimp. A closed insulation crimp or an open insulation crimp (in particular V crimp or B crimp, O crimp or OV crimp) can be used here. For more information

• to design a generic crimping tool,
• on possible areas of application of the generic crimping tool and / or
• to different possible types of crimp connections that can be made using the generic crimping pliers,
  is on the work
• " Crimping technology, production of reliable connections of electrical conductors and plugs "of WEZAG GmbH tool factory, Die Bibliothek der Technik 342, Verlag Moderne Industrie, ISBN 978-3-68236-027-7

referenced.

In contrast, a generic crimping tool is preferably used for the mechanical fluid-tight connection in fluid technology, for example to connect pipes to one another or to fluidic connectors. In this case, plastic deformation of the pipes to be connected or a so-called fitting ensuring the mechanical connection and the fluid-tight seal takes place by means of the pressing tongs. Exemplary embodiments of a generic pressing tongs can be found in the publications DE 197 09 639 A1 , DE 198 34 859 C2 , DE 199 24 086 C2 , DE 199 24 087 C2 , DE 199 63 097 C1 , DE 103 46 241 B3 , DE 10 2007 001 235 B4 , DE 10 2008 005 472 B3 , EP 3 208 044 A1 , EP 2 995 424 A1 can be removed.

U.S. 5,280,716 A discloses crimping pliers in which a fixed pliers part forms a fixed hand lever and a fixed pliers jaw. In the area of the pliers head, a movable pliers jaw is mounted on the fixed pliers part via a pivot bearing. Aside from the swivel bearing, a movable hand lever is articulated on the movable pliers jaw. The movable hand lever is additionally supported on the fixed hand lever via a pressure lever. A first spring is articulated with a spring base between the pivot bearing and the articulation of the pressure lever on the movable hand lever, while the other spring foot point is articulated on the fixed hand lever. The first spring acts on the movable hand lever in the opening direction. A second spring, which is designed as a torsion leg spring, acts on the pressure lever in the opening direction. As a result of the action of the two springs, the crimping pliers assume an open position without the hand of the user acting on the hand lever, while an at least partial closure of the hand lever requires the user to apply closing forces to the hand lever. The bolt, via which the pressure lever is articulated to the movable hand lever, is guided in an elongated hole, with which it can assume a first position and a second position. From the open position to a partially closed position, the bolt assumes the first position, in which the drive connection designed as a toggle lever drive has a relatively large transmission ratio, with which small forces are generated in the area of the pincer jaws, but large closing angles of the pincer jaws can be brought about. When the partially closed position is reached, for which the dies held on the pliers jaws are just resting on the outer surface of the workpiece, the bolt is automatically transferred to the second position due to the alignment of the elongated hole, which means that the drive connection is switched to a smaller translation, with which then larger forces can be brought about on the pliers jaws. Intermediate locking positions can be secured using a compulsory lock.

In the case of an otherwise basically corresponding design of a crimping tool, the procedure is in accordance with U.S. 4,048,877 A the movable hand lever is not supported by a pressure lever on the fixed hand lever. Rather, the movable hand lever carries a role which rolls over the crimp stroke on a cam profile of the fixed hand lever, the gear ratio of the drive mechanism being changed depending on the contouring of the cam profile with the rolling movement. For these crimping pliers, a first spring acting directly between the hand levers ensures that the roller always rests on the cam profile. A second spring acts on the two jaws in the opening direction. Has that Cam profile over at least one valley, with the entry of the roller mounted on the movable hand lever into the valley, a stable intermediate position can be ensured in which the crimping pliers do not open further by the second spring, since the roller counteracts a rise area delimiting the valley the action of the first spring would have to overcome. These crimping pliers also have a compulsory lock.

Another crimping tool is off WO 93/19897 A1 known.

OBJECT OF THE INVENTION

The invention is based on the object of proposing manually operated crimping or crimping pliers which are improved in terms of force ratios, ease of use and safety.

SOLUTION

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

DESCRIPTION OF THE INVENTION

1. a) Einerseits kann es wünschenswert sein, dass in der Press- oder Crimpzange zwischen den Zangenbacken eine Feder wirkt. Die Feder beaufschlagt die Zangenbacken in Schließrichtung. In diesem Fall erfolgt eine Öffnung eines Zangenmauls, welches von Gesenken der Press- oder Crimpzange ausgebildet ist, durch Öffnung der Zangenbacken über die antriebsverbundenen Handhebel gegen die Wirkung der Feder. Ist dann ein Werkstück in das Zangenmaul eingelegt, beaufschlagt die Feder beim Loslassen eines Handhebels die Zangenbacken aufeinander zu. Somit ist auch ohne manuelle Applikation einer Kraft auf die Handhebel infolge der Feder das Werkstück zwischen den Gesenken verspannt. Auf diese Weise kann das Werkstück in dem Zangenmaul hinsichtlich seiner Lage und gegenüber einem unbeabsichtigten Herausfallen gesichert sein.
2. b) Andererseits hat sich gezeigt, dass es vorteilhaft sein kann, wenn sich die Press- oder Crimpzange nach dem Durchlaufen des Arbeitshubs von selber öffnet. Somit wird in bekannten Press- oder Crimpzangen auch eine Feder eingesetzt, welche die Zangenbacken in Öffnungsrichtung beaufschlagen.

The invention is based on the knowledge that the design of crimping or crimping pliers can lead to a conflict of objectives:

1. a) On the one hand, it can be desirable for a spring to act in the pressing or crimping pliers between the pliers jaws. The spring acts on the jaws in the closing direction. In this case, the jaws of the pliers, which are formed by the dies of the pressing or crimping pliers, are opened by opening the pliers jaws via the hand lever connected to the drive against the action of the spring. If a workpiece is then placed in the jaws of the pliers, the spring acts on the jaws of the pliers when a hand lever is released. Thus, even without manual application of a force to the hand lever, the workpiece is between the dies due to the spring tense. In this way, the workpiece can be secured in the pliers jaw with respect to its position and against accidental falling out.
2. b) On the other hand, it has been shown that it can be advantageous if the crimping or crimping pliers open by themselves after having completed the working stroke. Thus, a spring is also used in known pressing or crimping pliers, which act on the pliers jaws in the opening direction.

For crimping or crimping pliers known from the prior art, the conflict of objectives cannot be resolved. Thus - depending on the assessment of the importance of the aforementioned, conflicting objectives - the manufacturer of the crimping or crimping pliers had to decide between a spring acting in the opening direction or a spring acting in the closing direction.

According to the invention, pressing or crimping pliers are proposed which have two pliers jaws (supporting or forming dies). The pliers jaws are drive-connected via a suitable drive mechanism with two hand levers. Here, a working stroke of the tong jaws from an open position of the tong jaws into a closed position of the tong jaws can be brought about by relative movement of the hand lever. The working stroke can have an "idle stroke" in which the dies are first placed against the workpiece, as well as a press or crimp stroke in which the workpiece is pressed or crimped between the dies. At least one spring device is used in the pressing or crimping pliers according to the invention.

The at least one spring device is designed in a special way within the scope of the invention and is integrated into the force flow: the at least one spring device initially ensures an equilibrium position. In the equilibrium position, the spring device does not exert any force on the jaws. In the event that a single spring device is used, this spring device is not tensioned in the equilibrium position (or is only tensioned to such a small extent that friction or any other resistance in the crimping pliers cannot be overcome). In the event that several spring devices are used, none of them can be tensioned or the action of the tensioned spring devices cancels one another. The said equilibrium position the pincer jaw is arranged between the open position and the closed position of the pincer jaws (for example between 20% to 80% or 30% to 60% of the working stroke).

The equilibrium position divides the working stroke into a first partial working stroke, which is arranged between the open position and the equilibrium position of the gripper jaws, and a second partial working stroke, which is arranged between the equilibrium position and the closed position. In the first partial working stroke, the at least one spring device exerts a closing force on the gripper jaws. In contrast, the spring device exerts an opening force on the jaws in the second partial working stroke.

• Zu Beginn eines Press- oder Crimpvorgangs befindet sich die Press- oder Crimpzange in der Gleichgewichtsstellung. Die Gleichgewichtsstellung ist stabil, da die Federeinrichtung bei kleinen Auslenkungen in Öffnungsrichtung eine Schließkraft und bei kleinen Auslenkungen in Schließrichtung eine Öffnungskraft herbeiführt. Auf diese Weise kann automatisch eine Rückführung in die Gleichgewichtsstellung erfolgen.
• Soll ein Werkstück in ein (von Gesenken der Press- oder Crimpzange ausgebildetes) Zangenmaul eingelegt werden, kann der Benutzer durch Aufbringung einer Öffnungskraft auf die Handhebel eine Öffnung der Zangenbacken in Richtung der Öffnungsstellung herbeiführen.
• Ist das Werkstück in das Zangenmaul eingelegt und sind die Abmessungen des Werkstücks gegenüber der Größe des Zangenmauls derart, dass ohne ein Verpressen oder Vercrimpen des Werkstücks eine Schließung der Zangenbacken mit den Gesenken zurück bis in die Gleichgewichtsstellung nicht möglich ist, werden die Zangenbacken mit den Gesenken durch die Federeinrichtung mit der Schließkraft gegen das Werkstück gepresst. Dadurch wird eine Sicherung der Position und/oder Lage des Werkstücks in dem Zangenmaul (und auch ein Herausfallen des Werkstücks aus dem Zangenmaul) gewährleistet, auch wenn der Benutzer keine Schließkraft auf die Handhebel aufbringt.
• Wird dann der Press- oder Crimphub ausgeführt, indem der Benutzer durch Aufbringung einer Schließkraft auf die Handhebel die Schließstellung der Zangenbacken herbeiführt, kann nach Beendigung des Press- oder Crimphubs die Federeinrichtung in dem zweiten Teilarbeitshub eine Öffnungskraft auf die Zangenbacken ausüben. Hierdurch "springt" das Zangenmaul nach Beseitigung der auf die Handhebel applizierten Schließkräfte durch den Benutzer automatisch auf.

This embodiment according to the invention enables in particular the following advantageous use of the crimping or crimping pliers:

• At the beginning of a pressing or crimping process, the pressing or crimping pliers are in the equilibrium position. The equilibrium position is stable because the spring device brings about a closing force with small deflections in the opening direction and an opening force with small deflections in the closing direction. In this way, a return to the equilibrium position can take place automatically.
• If a workpiece is to be inserted into a pliers jaw (formed by dies of the crimping or crimping pliers), the user can bring about an opening of the pliers jaws in the direction of the opening position by applying an opening force to the hand lever.
• If the workpiece is inserted into the jaws and the dimensions of the workpiece compared to the size of the jaws are such that it is not possible to close the jaws with the dies back to the equilibrium position without pressing or crimping the workpiece, the jaws with the dies pressed against the workpiece by the spring device with the closing force. This ensures that the position and / or location of the workpiece in the pliers jaws (and also that the workpiece falls out of the pliers jaws) is ensured, even if the user does not apply any closing force to the hand lever.
• If the press or crimp stroke is then carried out in that the user brings about the closed position of the pliers jaws by applying a closing force to the hand lever, the spring device in the second can, after completion of the press or crimp stroke Partial working stroke exert an opening force on the gripper jaws. As a result, the pliers jaws "open" automatically after the user has eliminated the closing forces applied to the hand lever.

The spring device preferably generates a non-linear characteristic of the spring force. The non-linear characteristic of the spring force exhibits a kink and / or a jump, particularly in the equilibrium position or between the two partial working strokes.

The spring device can have one or more springs. Here, the at least one spring can be made from any material (for example metal, plastic, an elastomer material) and also from a composite material. It can be a compression spring, tension spring, an angle spring, a torsion spring or a spring of any other type. If several springs are used, they can be arranged in mechanical series connection or parallel connection and / or integrated into the force flow at different points. It is also possible that one spring acts in the opening direction and another spring acts in the closing direction. The spring device preferably generates a non-linear characteristic which, in particular, has a kink and / or a jump in the equilibrium position or between the two partial working strokes.

For one embodiment of the invention, the spring device has a closing spring and an opening spring. In this case, the closing spring generates the closing force in the first partial working stroke, while the opening spring generates the opening force in the second partial working stroke. It is possible here that the opening spring is decoupled from the drive connection in the first partial working stroke, while the closing spring can be decoupled from the drive connection in the second partial working stroke.

For another variant of the invention, the spring device (preferably exclusively) has a spring. This spring is then used multifunctionally in that it generates the closing force in the first partial working stroke as well as generating the opening force in the second partial working stroke.

Within the scope of the invention, it is entirely possible for a spring of the spring device to be coupled to the movement of the tong jaws over the entire working stroke. In this case changed the loading of the spring over the entire working stroke. For a particular proposal of the invention, the pressing or crimping pliers have at least one stop. The stop specifies an extreme deflection of a spring base point of the spring device, which is preferably a minimal deflection. Furthermore, a driver is available for this embodiment of the pressing or crimping pliers. In the partial working stroke, the driver takes the spring base point of the spring device with it and moves it away from the stop, which then changes the action on the spring. The spring base of the spring device preferably remains at the stop in the other partial working stroke. Thus, the application of the spring does not change for the other partial working stroke.

If the spring is a compression spring, the stop specifies a minimal application of pressure to the compression spring. In the partial working stroke in which the driver takes the spring base of the compression spring with it and moves it away from the stop, the compressive force in the compression spring increases. The increasing compressive force of the compression spring can then be used to generate the closing force or the opening force. The same applies to the use of a tension spring - here the stop provides a minimum tensile force in the tension spring, while the deflection and the tensile force increase as the driver continues to act on the tension spring.

For a particular proposal of the invention, there are two stops and associated drivers. A single spring can be caught on the two stops in the equilibrium position. In this case, a spring base point of the spring is carried along by a driver during the first partial working stroke. In the other partial working stroke, the other spring base point is taken along by the other driver. If, on the other hand, two springs are used, each spring can be supported on an associated stop in the equilibrium position. In this case, during a partial working stroke, a driver moves the spring base point of a spring away from the assigned stop, while the other spring base point remains at the assigned stop. In the other partial working stroke, the other driver then moves the spring base of the other spring away from the associated stop, while in this case the spring base of the first-mentioned spring continues to be supported on the stop.

The at least one stop and the at least one driver can be arranged on any components of the crimping or crimping pliers, as long as one during the working stroke Relative movement of the components on which the stop and the driver are arranged takes place. For example, it is possible for the driver to be supported on a hand lever, while the assigned stop is attached to a (preferably moved) pliers jaw. For an embodiment of the crimping or crimping pliers according to the invention, however, the stop is attached to a pliers head or carried by this, while the driver is attached to or carried by a pliers jaw moved over the working stroke with respect to the pliers head. If there are two stops and drivers, this can also apply to both stops and drivers.

In principle, the at least one spring of the spring device can be designed as desired. For a special embodiment of the spring device, a single spring is used, which is designed as a U-shaped spiral spring or leaf spring. Such a spiral spring or leaf spring represents a structurally simple spring with a long service life, in which the cross sections of the spiral spring or leaf spring and possibly the cross-sectional profile, the course of the longitudinal axis of the spiral spring or leaf spring, the material used and the effective length of the spiral spring or leaf spring the stiffness and any non-linearity of the stiffness behavior can be specified constructively. Because the spiral spring or leaf spring is U-shaped, the different spring arms of the U can be used to configure the rigidity.

A particularly good integration of the U-shaped spiral spring or leaf spring into the pressing or crimping pliers can result for an embodiment of the invention if the spring arms of the U-shaped spiral spring or leaf spring extend in the direction of a longitudinal axis of the pliers head or in the direction of the closed hand lever .

For a further suggestion, the crimping or crimping tool is equipped with an automatic lock. Such a compulsory lock secures a partial closed position of the jaws against an opening that has been reached. As a result, a partial closed position is maintained even if the manual forces acting on the hand lever are temporarily eliminated. Such a compulsory lock enables the jaws to be opened only when the working stroke has been completed. With these measures, the process reliability can be increased. As a result of the embodiment according to the invention, the spring device automatically moves the gripper jaws back into the equilibrium position when the working stroke is fully completed (that is, when the automatic locking mechanism is unlocked). Preferably is in the frame According to the invention, the automatic locking mechanism is designed in such a way that it is only effective in the second partial working stroke (or only in an end partial section of the same), so that this does not hinder the desired effect of the spring device in the first partial working stroke.

It is entirely possible within the scope of the invention that the open position (in which the workpiece can be inserted into the jaws of the pliers) is only maintained in view of the action of the spring device if the user applies opening forces to the hand lever or the pliers jaws, which the force of the action of the pliers jaws counteract by the spring device. For a further suggestion of the invention, the need to manually hold the crimping or crimping pliers in the open position can be avoided: a latching device or a locking device is available for this suggestion. The latching device or locking device secures the open position so that the open position can be automatically maintained despite the closing force of the spring device acting in the open position.

In this context, a locking device is understood to mean, in particular, a device that effects a locking that leads to a locking force that is greater than the closing force generated by the spring device. By applying manual closing forces (for example by means of the hand lever or by closing forces applied directly to the pliers jaws) the detent can be overpressed so that the open position is left. If the latching is overridden in this way, the latching force is at least partially eliminated. As a result of this omission, the closing force generated by the spring device predominates. A return to the equilibrium position (or a placement of the dies on the workpiece as a result of the spring device) is thus possible.

In contrast, a locking device is understood to mean in particular a device in which an open position is locked in such a way that it cannot be left simply by applying closing forces (for example via the hand lever or by closing forces applied directly to the pliers jaws). Rather, manual actuation of a locking element is required, which then releases the locking so that the spring device can then bring the pliers jaws back into the equilibrium position or bring the dies to the workpiece.

It is entirely possible for a separately designed latching or locking spring to be used in the latching device or locking device. For an embodiment of the pressing or crimping pliers according to the invention, the spring or a spring of the spring device is multifunctional in that this spring generates the opening force and / or the closing force on the one hand. In addition, this spring also generates a locking force of the locking device or a locking force of the locking device.

There are many possibilities for the structural design of such a multifunctional spring. For a proposal of the invention, a spring arm of the U-shaped leaf spring or spiral spring carries a latching spring arm of the latching device. In this case, the detent spring arm resiliently forms a detent element or carries it. The latching element interacts with a latching counter-latching element, with a relative movement of the counter-latching element relative to the latching element taking place over the working stroke and in particular in the area surrounding the open position.

Another embodiment of the pressing or crimping pliers according to the invention has a special construction of the pressing or crimping pliers and a special drive kinetics: For this embodiment, a fixed pliers part (which can be made in one or more pieces) forms a fixed pliers jaw and a fixed hand lever out. A movable pliers part (which can also be designed in one or more pieces) then forms a movable pliers jaw. The movable tong part is pivotably articulated to the fixed tong part via a pivot bearing. A movable hand lever is pivotably articulated to the fixed pliers part via a pivot bearing. The movable hand lever is then connected to the movable pliers part via a drive connection (in particular a pressure lever drive or a toggle lever drive).

For a proposal of the invention, the movable hand lever forms the counter-locking element in this case.

For a structural design of the crimping or crimping pliers, the pivot bearing, via which the movable pliers part is pivotably articulated to the fixed pliers part, is arranged in the half of the longitudinal extension of the fixed pliers part facing away from the pliers head (the pivot bearing in this case, for example Can be located at a distance from the front end region of the long head which is more than 55%, more than 60%, more than 65%, more than 70% or even more than 75% of the length of the fixed pliers part). By moving the pivot bearing away from the pliers head, the pivot radius of the dies can also be increased. For a given stroke of the dies, the swivel angle of the dies can be reduced over the working stroke in this way. Too much pivoting of the dies relative to one another has proven to be negative for the pressing or crimping result.

Advantageous further developments of the invention emerge from the patent claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the description are only exemplary and can come into effect alternatively or cumulatively without the advantages necessarily having to be achieved by embodiments according to the invention. The invention is specified by independent claim 1, preferred embodiments are defined by the dependent claims.

The number of features mentioned in the claims and the description are to be understood in such a way that precisely this number or a greater number than the stated number is present without the need for the explicit use of the adverb "at least". So if, for example, a spring is mentioned, it is to be understood that there is exactly one spring, two springs or more springs. These characteristics can be supplemented by other characteristics or be the only characteristics that make up the product in question.

The reference signs contained in the claims do not represent a restriction of the scope of the subject matter protected by the claims. They only serve the purpose of making the claims easier to understand.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

zeigt eine Crimpzange in einer räumlichen Explosionsdarstellung.

Fig. 2

zeigt die Crimpzange gemäß Fig. 1 in einer räumlichen Darstellung.

Fig. 3

zeigt in einer Seitenansicht Bauelemente der Crimpzange gemäß Fig. 1 und 2 zur Verdeutlichung der Antriebskinetik.

Fig. 4, 6, 8, 10

zeigen die Crimpzange gemäß Fig. 1-3 in Seitenansichten in unterschiedlichen Betriebsstellungen.

Fig. 5, 7, 9, 11

zeigen Details V, VII, IX, XI der Crimpzangen gemäß Fig. 4, 6, 8, 10.

Fig. 12

zeigt eine alternative Ausführungsform einer Crimpzange in einer Seitenansicht.

Fig. 13

zeigt ein Detail XIII der Crimpzange gemäß Fig. 12.

Fig. 14

zeigt unterschiedliche Federcharakteristiken einer Federeinrichtung einer Press- oder Crimpzange.

In the following, the invention is further explained and described with reference to preferred exemplary embodiments shown in the figures.

Fig. 1

shows a crimping tool in a three-dimensional exploded view.

Fig. 2

shows the crimping tool according to Fig. 1 in a spatial representation.

Fig. 3

shows in a side view components of the crimping tool according to FIG Fig. 1 and 2 to clarify the drive kinetics.

Figures 4, 6, 8, 10

show the crimping tool according to Fig. 1-3 in side views in different operating positions.

Figures 5, 7, 9, 11

show details V, VII, IX, XI of the crimping pliers according to FIG Fig. 4 , 6 , 8th , 10 .

Fig. 12

shows an alternative embodiment of a crimping tool in a side view.

Fig. 13

shows a detail XIII of the crimping tool according to FIG Fig. 12 .

Fig. 14

shows different spring characteristics of a spring device of a crimping tool.

FIGURE DESCRIPTION

Figs. 1 to 11 show a crimping tool 1 in panel construction. The crimping pliers 1 has a fixed pliers part 2 and a movable pliers part 3. The fixed pliers part 2 has two fixed ones

Pliers part plates 4a, 4b. The movable tong part 3 has two movable tong part plates 5a, 5b. The fixed pliers part 2 has a fixed pliers jaw 6, a connection area 7 and a fixed hand lever 8. For the exemplary embodiment shown, the fixed pliers part plate 4a forms the fixed pliers jaw 6, the connection area 7 and the fixed hand lever 8. In contrast, the fixed pliers part plate 4b only forms the fixed pliers jaw 6 and the connecting area 7. The movable tong part 3 has a movable tong jaw 9. The movable tong jaw 9 is held on a pivot bracket 10. Here, the movable tong part plates 5a, 5b are designed in two parts with tong jaw plates 11a, 11b and pivoting support plates 12a, 12b.

The movable tong part 3 is mounted on the fixed tong part 2 via a pivot bearing 13 so as to be pivotable about a pivot axis 14. In the illustrated embodiment, this is done by a pivot pin 15. The pivot pin 15 extends through through bores 16a, 16b, 16c, 16d of the movable pliers part plates 5a, 5b and fixed pliers part plates 4a, 4b, which allow pivoting. The two movable pliers part plates 5a, 5b are received between the fixed pliers part plates 4a, 4b. The tong jaw plates 11a, 11b are attached to the pivoting support plates 12a, 12b and held thereon such that the tong jaw plates 11a, 11b extend in the parallel planes given by the fixed tong part plates 4a, 4b and move in these planes during the pivoting.

Approximately in the center of the pivot support plate 12, an end region of a pressure lever 18 (which is formed here with two pressure lever plates 19a, 19b) is articulated to the movable pliers part 3 via a pivot bearing 17. For the illustrated embodiment, the pivot bearing 17 is formed with a pivot pin 20. The pivot bolt 20 is received in through bores 21a, 21b, 21c, 21d of the pressure lever plate 19b, the pivot support plate 12b, the pivot support plate 12a and the pressure lever plate 19a. In this way, a pivot axis 22 of the pivot bearing 17 is predetermined. For the illustrated embodiment, the two pressure lever plates 19 are not arranged between the fixed pliers part plates 4a, 4b, but outside the same. For this reason, the pivot pin 20 extends through elongated holes 23a, 23b of the fixed pliers part plates 4a, 4b. The elongated holes 23a, 23b are shaped and arranged in such a way that the fixed tong part plates 4a, 4b do not hinder the movement of the pivot pin 20 with the pivoting of the movable tong part 3.

A movable hand lever 24 (which here has two movable hand lever plates 25a, 25b) is mounted on the fixed pliers part 2 such that it can pivot via a pivot bearing 26 with a pivot axis 27. For this purpose the fixed pliers part plate 4b, the hand lever plate 25b, the hand lever plate 25a and the fixed pliers part plate 4a have through bores 28a, 28b, 28c, 28d. A pivot bolt 29 extends through the through bores 28a, 28b, 28c, 28d. The pivot bolt 29 enables a relative pivoting movement of the movable hand lever 24 with respect to the fixed pliers part 2.

The pressure lever 18 is pivotably connected to the hand lever 24 via a pivot bearing 30. For this purpose, the pressure lever plates 19a, 19b have through bores 31a, 31d. The hand lever plates 25a, 25b have through bores 31b, 31c adjacent to the through bores 28b, 28c. A pivot pin 32, which enables a pivoting movement, extends through the through bores 31b, 31c. Since for this purpose the pivot pin 32 has to pass through the fixed tong part plates 4a, 4b, the fixed tong part plates 4a, 4b have elongated holes 33a, 33b. The elongated holes 33a, 33b ensure that the degree of freedom of movement of the pivot pin 32 is not hindered.

The aforementioned pairs of components or plates extend symmetrically on both sides of a central pliers plate plane. A spring 34, which is part of a spring device 35, is arranged in this central pliers plate plane. For the exemplary embodiment shown, the spring 34 is designed as a U-shaped leaf spring or spiral spring 36.

A compulsory lock 37 is used in the crimping tool 1. The automatic locking mechanism 37 has a locking pawl 38. The pawl is carried by a pawl shaft 39 here. The pawl shaft 39 is rotatably mounted on the pressure lever plates 19a, 19b. The pawl shaft 39 extends, without restricting the degree of freedom of movement, through through recesses 40a, 40b of the fixed pliers part plates 4a, 4b. In the area of interaction with the pawl 38, the hand lever 24 forms a locking toothing 41 in the area of its peripheral surface. During the closing movement of the hand lever 24, the pawl 38 slides like a ratchet as a result of being acted upon by a spring 42 along the locking toothing 41 reverse direction is excluded. If, however, the closed position of the crimping pliers 1 has been reached, the pawl 38 has passed the locking teeth 41. Thus, the pawl 38 as a result of the tensile force generated by the spring 42 "fold over". After folding over, the pawl 38 can then slide along the locking toothing 41 during an opening movement.

In Fig. 2 it can be seen that the tong jaws 6, 9 each carry a die 43, 44 in an exchangeable manner. For this purpose, a connection of the tong jaws 6, 9 with the dies 43, 44 is preferably used, as is the case in the patent DE 198 02 287 C1 is described.

The drive kinetics can be based on the representation according to Fig. 3 explain: As a result of the mounting of the movable gripper part 3 with the pivot bracket 10 and the gripper jaw plate 11 via the pivot bearing 13 on the fixed gripper part 2, a relative movement of the gripper jaws 6, 9 can take place. This relative movement of the jaws 6, 9 is brought about by the pivoting of the hand lever 24 relative to the fixed pliers part 2 about the pivot bearing 26. The hand lever 24 forms a first toggle lever 45 between the pivot bearings 26, 30. A second toggle lever 46 is located between the pivot bearings 17, 30 formed by the pressure lever 18. The pivot bearing 30 forms the knee joint of a toggle lever drive 47 formed with the toggle levers 45, 46. The toggle lever drive 47 converts the pivoting movement of the hand lever 24 into a pivoting movement of the movable pliers part 3 relative to the fixed pliers part 2.

The spring device 45 is explained in more detail below:
According to Fig. 4 the crimping pliers 1 is in an equilibrium position 48. In the equilibrium position 48, an opening angle of the hand lever is, for example, in the range from 40 ° to 50 °, in particular 45 ° to 48 °. The fixed pliers part 2 carries two stops 49, 50. Here, the stops 49, 50 are designed as bolts carried in through bores of the fixed pliers part plates 4a, 4b. In the equilibrium position 48, the U-shaped leaf spring or spiral spring 36 with the spring arms 51, 52 (formed by the approximately parallel side legs of the U) rests on the outside against an associated stop 49, 50. Here, the leaf spring or spiral spring 36 and the spring arms 51, 52 cannot be pretensioned in the equilibrium position 48. However, it is also possible that the leaf spring or spiral spring 36 is pretensioned so that it is tensioned between the stops 49, 50.

On the opposite sides of the leaf spring or spiral spring 36 (and preferably in the free end area of the spring arms 51, 52) the movable pliers part 3 carries drivers 54, 55 In the illustrated embodiment, the drivers 54, 55 are designed as driver pins which are held in bores in the movable pliers sub-plates 5a, 5b. In this case, the driver pin forming the driver 54 is multifunctional, since it is also used to fasten the jaw plate 11 to the pivot bracket 10. In the in the Fig. 4 and 5 In the equilibrium position 48 shown, the drivers 54, 55 are just resting against the leaf spring or spiral spring 36 without generating a significant contact pressure here.

Fig. 6 and 7th show the crimping pliers 1 in a closed position 53 in which an angle of the hand levers 8, 24 is, for example, in the range from 0 ° to 10 ° (preferably in the range from 0 ° to 5 °).

The pivoting of the movable pliers part 3 from the equilibrium position 48 according to FIG Fig. 4 and 5 in the closed position 53 according to Fig. 6 and 7th (and the associated relative movement of the drivers 54, 55 with respect to the fixed pliers part 2) has the consequence that the driver 55 moves away from the spring arm 51. The driver 55 is increasingly pressed against the spring arm 52 during this movement. The leaf spring or spiral spring 36 is thus additionally acted upon. The restoring force of the leaf spring or spiral spring 36 caused by this acts as an opening force in the opening direction. During the loading of the leaf spring or spiral spring 36 caused by the driver 54, the leaf spring or spiral spring 36 is released from the stop 50. The leaf spring or spiral spring 36 moves increasingly away from the stop 50 until the closed position 53 is reached Fig. 6 , 7th when the automatic locking mechanism 37 reaches the opening movement of the hand levers 8, 24, the crimping pliers 1 can automatically "spring open" with the elimination of the manual forces. The crimping pliers 1 automatically return from the closed position 53 to the equilibrium position 48 as a result of the action of the spring device 35.

If, however, the crimping tool 1 is transferred from the equilibrium position 48 according to FIG Fig. 4 and 5 in a partially open position 56 according to Fig. 8 and 9 or in a (maximum) open position 57 according to Fig. 10 and 11 (whereby, for example, in the partially open position 56 the opening angle of the hand levers 8, 24 can be in the range from 60 ° to 70 °, preferably 65 ° to 68 °, and the opening angle of the hand levers 8, 24 in the open position 57 in the range from 80 ° to 100 °, preferably 85 ° to 95 °), the relative movement of the movable tong part 3 with respect to the fixed tong part 2 causes the driver 54 to move away from the spring arm 52, while the spring arm 52 is still supported on the stop 50. At the same time, the driver 55 increases with the opening movement Force exerted on the spring arm 51. The increasing force results in an increasing deformation of the leaf spring or spiral spring 36 and the movement of the spring arm 51 away from the stop 49. The increasing loading of the leaf spring or spiral spring 36 has the consequence that the leaf spring or spiral spring 36 exerts a closing force on the tong parts 2, 3 and thus the tong jaws 6, 9. The closing force is aimed at restoring the equilibrium position 48.

For the exemplary embodiment shown, the crimping pliers 1 has a locking device 58 as an optional equipment variant. The open position 57 can be locked via the locking device 58 in such a way that the open position 57 is maintained despite the closing force of the spring device 35. Only a manual overpressure of the latched open position 57 (which results in a reduction of the latching force or complete elimination of the latching force of the latching device 58) enables the spring device 35 to automatically restore the equilibrium position 48 by means of the closing force provided by the leaf spring or spiral spring 36. In the locking device 58, a locking element 60 (which in particular forms a projection [or a recess]) is pressed against a counter-locking element 61 (which in particular forms a recess [or a projection]) via a locking spring 59, wherein (at least in the surrounding area of the Open position 57) a movement of the hand levers 8, 24 or the pliers jaws 6, 9 relative to one another leads to a relative movement of the latching element 60 and the counter-latching element 61.

For the illustrated embodiment, the detent spring 59 of the detent device 58 is formed by a detent spring arm 62 of the leaf spring or spiral spring 36 (here a longitudinal section that extends transversely from the spring arm 52 in the direction of the hand lever 24). In the free end region of the detent spring arm 62 that comes into operative connection with the hand lever 24, the detent spring arm 62 carries a pin 63 which forms the detent element 60. In this case, the counter-latching element 61 is formed by a recess 64 of a latching contour 65 of the hand lever 24. As it approaches the open position 57, the pin 63 slides with elastic pressure through the detent spring arm 62 along the detent contour 65. When the open position 57 is reached, the pin 63 engages in the recess 64 as a result of the elastic application of the detent spring arm 62. The contact pressure of the latching element 60 on the counter-latching element 61 (i.e. the bias of the latching spring arm 62) and the geometry of the latching contour 65 (in particular the depth of the recess 64 and the inclination of the latching contour 65 in the region of the recess 64) is chosen so that the closing force of the spring device 35 cannot overcome the locking of the locking device 58. Rather, for this purpose, the user must move the hand lever 24 in the closing direction in such a way that the latching element 60 can be released from the counter-latching element 61 (that is to say the pin 63 can emerge from the recess 64).

It is possible that the leaf spring or spiral spring 36 is pivotably mounted on the movable pliers part 3 via a pivot pin 66.

Fig. 12 and 13 show an example of a further embodiment of the spring device 35 encompassed by the invention. In this case, a coupling arm 67 of the hand lever 24 extends into the region of the movable pliers part 3. The free end region of the coupling arm 67 in this case is shown in FIG Fig. 12 and 13 The equilibrium position 48 shown is caught between two compression springs 68, 69. The compression spring 68 forms an opening spring 70, and the compression spring 69 forms a closing spring 71.

1. a) Möglich ist, dass die Druckfedern in der in Fig. 12 und 13 dargestellten Gleichgewichtsstellung 48 nicht vorgespannt sind. In diesem Fall führt eine Öffnung der Handhebel 8, 24 dazu, dass sich der Kopplungsarm 67 von der Öffnungsfeder 70 wegbewegt. Gleichzeitig wird von dem Kopplungsarm 67 die Schließfeder 71 komprimiert, so dass diese die angestrebte Schließkraft erzeugen kann. Umgekehrt führt eine Schließung der Handhebel 8, 24 aus der Gleichgewichtsstellung 48 dazu, dass sich der Kopplungsarm 67 von der Schließfeder 71 wegbewegt. Die Öffnungsfeder 70 wird zunehmend beaufschlagt, womit die angestrebte Öffnungskraft erzeugt werden kann.
2. b) Möglich ist auch, dass in der Gleichgewichtsstellung 48 die Druckfedern 68, 69 keine Kraft auf den Kopplungsarm 67 ausüben, aber die Druckfedern 68, 69 (mit gleicher Vorspannkraft oder unterschiedlichen Vorspannkräften) vorgespannt sind. Ein derartiges Ausführungsbeispiel ist in Fig. 12 und 13 dargestellt. In diesem Fall ist die Expansion der Druckfedern 68, 69 und die Erzeugung einer Anpresskraft derselben an den Kopplungsarm 67 in der Gleichgewichtsstellung 48 unterbunden dadurch, dass die Bewegung der Druckfeder 68, 69 verbunden ist mit der Bewegung einer Federstange. Die Federstange trägt einen Ringabsatz 72, 73. In der Gleichgewichtsstellung 48 liegen die Ringabsätze 72, 73 an Anschlägen 49, 50 (die hier von den Führungen der Druckfedern 68, 69 oder der Federstangen ausgebildet sind) an. Eine Verschwenkung der Handhebel 8, 24 aus der Gleichgewichtsstellung 48 erfordert die Überwindung der Vorspannung der jeweiligen in Bewegungsrichtung angeordneten Druckfeder 68, 69. Einer derartigen Bewegung kann die nicht in Bewegungsrichtung angeordnete Druckfeder 68, 69 nicht folgen, da diese durch die Anlage des Ringabsatzes 72, 73 an dem Anschlag 49, 50 an einer Entspannung gehindert ist. Somit gewährleisten die Anschläge 49, 50 eine extremale Auslenkung der Druckfedern 68, 69. Für dieses Ausführungsbeispiel bildet der Kopplungsarm 67 die Mitnehmer 54, 55.

There are different possibilities for the effect of the compression springs 68, 69:

1. a) It is possible that the compression springs in the in Fig. 12 and 13 shown equilibrium position 48 are not biased. In this case, an opening of the hand levers 8, 24 results in the coupling arm 67 moving away from the opening spring 70. At the same time, the closing spring 71 is compressed by the coupling arm 67 so that it can generate the desired closing force. Conversely, if the hand levers 8, 24 are closed from the equilibrium position 48, the coupling arm 67 moves away from the closing spring 71. The opening spring 70 is increasingly acted upon, with which the desired opening force can be generated.
2. b) It is also possible that in the equilibrium position 48 the compression springs 68, 69 exert no force on the coupling arm 67, but the compression springs 68, 69 are biased (with the same biasing force or different biasing forces). Such an embodiment is shown in Fig. 12 and 13 shown. In this case, the expansion of the compression springs 68, 69 and the generation of a pressing force of the same on the coupling arm 67 in the equilibrium position 48 is prevented by the fact that the movement of the compression spring 68, 69 is connected to the movement of a spring rod. The spring rod carries an annular shoulder 72, 73. The annular shoulders 72, 73 are in the equilibrium position 48 to stops 49, 50 (which are formed here by the guides of the compression springs 68, 69 or the spring rods). Pivoting the hand levers 8, 24 out of the equilibrium position 48 requires overcoming the pretensioning of the respective compression springs 68, 69 arranged in the direction of movement , 73 is prevented from relaxation on the stop 49, 50. The stops 49, 50 thus ensure an extreme deflection of the compression springs 68, 69. For this exemplary embodiment, the coupling arm 67 forms the drivers 54, 55.

As an optional variant for the embodiment according to Fig. 12 and 13 the latching device 58 has a latching element 60 (here a pin 63) carried by the fixed pliers part 2. The latching element 60 interacts with a latching contour 65 which is supported by an elastic latching spring arm 62 of the hand lever 24 and which forms the counter-latching element 61, here a recess 64.

Fig. 14 shows different characteristics 74, 75, 76 for the spring force 77 of the spring device 35 as a function of the opening angle 78 of the hand levers 8, 24. These characteristics 74, 75, 76 represent basic, schematic spring force curves that can be used for any configuration of the spring device 35 and the Pressing or crimping pliers 1 can be brought about. In the characteristics 74, 75, 76 the origin of the abscissa corresponds to the closed position 53. The equilibrium position 48 is also identified here. The specified maximum values of the characteristics 74, 75, 76 correlate with the opening position 57. In the ordinate, positive values indicate an opening force. Negative values on the ordinate represent a closing force of the spring device 35.

For the characteristic 74 shown with a solid line, the result is a smooth course of the spring force of the spring device 35 without a jump, a curve-shaped course also being possible depending on the spring characteristics of the spring used. Such a characteristic 74 can already be brought about with a single spring whose non-tensioned equilibrium position corresponds to the equilibrium position 48 and which then generates the opening force or the closing force when moving out of the equilibrium position 48 depending on the direction of movement.

For the embodiment according to Figs. 1 to 11 In principle, a characteristic according to the characteristic 74 can be brought about if the leaf spring or spiral spring 36 is not pretensioned in the equilibrium position 38. It should be noted, however, that, under certain circumstances, due to the different lever ratios of the drivers 54, 55, the characteristic 74 in the area of the equilibrium position 48 can also have a kink. This can also be used constructively in a targeted manner if different gradients of the characteristic 74 are desired in the partial working strokes. For the embodiment according to Fig. 12 and 13 A characteristic 74 is used when, in the equilibrium position 48, the opening spring 70 and the closing spring 71 are not pretensioned and the opening spring 70 and the closing spring 71 have the same spring stiffness.

The characteristic 75 shown in broken lines has a jump in the equilibrium position. This can be desirable if a particularly stable equilibrium position 48 is to be ensured with relatively large restoring forces in the same and / or in the two partial working strokes, the characteristic 75 should have a relatively low gradient at a high level of force. Such a characteristic 75 can for the embodiment according to FIG Figs. 1 to 11 be brought about by the leaf spring or spiral spring 36 being pretensioned between the stops 49, 50 in the equilibrium position 48. The extent of the bias specifies the level of the jump in the characteristic 75. In contrast, the slope of the characteristic 75 in the two partial working areas is predetermined by the flexural rigidity of the leaf spring or spiral spring 36. For the exemplary embodiment according to FIG Fig. 12 and 13 A characteristic 75 can be brought about in that the opening spring 70 and the closing spring 71 are pretensioned in the equilibrium position 48 without these (as a result of the interaction between the annular shoulders 72, 73 and the stops 49, 50) exerting a force on the drivers 54, 55 produce.

Finally shows Fig. 14 Dot-dashed a characteristic 76 in which the exact equilibrium position 48 is not stable. Rather, the spring device does not generate any spring force in an area around the equilibrium position 48, so that this area is multistable. Only when this surrounding area is left does the illustrated characteristic 76 have a jump with an opening force or closing force that then increases further. Such a characteristic 76 can be brought about by, for the exemplary embodiment according to FIG Figs. 1 to 11 in the equilibrium position, the two drivers 54, 55 do not already bear against the leaf spring or spiral spring 36, as shown, but these are still spaced apart are arranged by this. The spacing of the drivers 54, 55 from the leaf spring or spiral spring 36 thus defines the area around the equilibrium position 48 for which no opening force and no closing force is generated. For the characteristic resulting therefrom, leaving the surrounding area (deviating from the characteristic 76 shown) then leads to jumps of the same height with a subsequent, same gradient of the characteristic in the partial working strokes 79, 80.

For that in the Fig. 12 and 13 In the embodiment shown, a characteristic like the characteristic 76 shown can be brought about by the drivers 54, 55 being arranged in the equilibrium position 48 at a distance from the two compression springs 68, 69 resting on the stops 49, 50. By selecting different pretensioning of the compression springs 68, 69, it is possible that (in accordance with the characteristic 76 shown) the jumps have different heights when the area around the equilibrium position 48 is left. It is then also entirely possible for compression springs 68, 69 to be used with different stiffnesses, so that the characteristic 76 has different gradients in the two partial working strokes.

It is possible that any other springs, such as tension springs, come into effect between any components of the crimping pliers 1 that are moved relatively during the working stroke without departing from the scope of the invention. Outside the equilibrium position 48 (or the explained environmental area in which the spring device 35 generates no force), a first partial working stroke 79 characterizes the operating positions of the crimping pliers 1 between the open position 57 and the equilibrium position 48, while a second partial working stroke 80 characterizes operating positions of the crimping pliers 1 between the equilibrium position 48 and the closed position 53 indicates. The entire stroke between the open position 57 and the closed position 53 is identified as the working stroke 81.

Functionally, a distinction can be made between the axial section with the hand levers 8, 24 and a pliers head 82 on the crimping pliers 1. In the area of the pliers head 82, the pliers jaws 6, 9 with the dies 43, 44, the drive mechanism with the toggle lever drive 47, the spring device 35 and the compulsory lock 37 are arranged.

In the present description, the invention has been explained primarily in connection with a crimping tool 1. A corresponding design is also possible for pressing tongs, with the features and designs according to the invention can be integrated, for example, into pressing tongs according to the prior art mentioned at the beginning.

Here, the design of a crimping pliers 1 in plate construction was explained, with components partially consisting of a pair of parallel plates. In fact, the same basic principle of crimping pliers 1 can be implemented if there are not pairs of plates, but only a single such component.

In the context of the present description, with regard to the function and / or design, corresponding or similar components are identified with the same reference numerals, but with a supplementary distinguishing letter a, b, .... This is then sometimes referred to without the use of the additional letter.

REFERENCE LIST

1

Crimping tool

2

fixed pliers part

3

movable pliers part

4th

fixed pliers part plate

5

movable pliers part plate

6th

fixed pliers jaw

7th

Connection area

8th

fixed hand lever

9

movable jaws

10

Swivel bracket

11

Jaw plate

12

Swivel support plate

13

Pivot bearing

14th

Swivel axis

15th

Pivot pin

16

Through hole

17th

Pivot bearing

18th

Pressure lever

19th

Pressure lever plate

20th

Pivot pin

21st

Through hole

22nd

Swivel axis

23

Long hole

24

movable hand lever

25th

movable hand lever plate

26th

Pivot bearing

27

Swivel axis

28

Through hole

29

Pivot pin

30th

Pivot bearing

31

Through hole

32

Pivot pin

33

Long hole

34

feather

35

Spring device

36

Leaf spring or spiral spring

37

Compulsory lock

38

Pawl

39

Ratchet shaft

40

Through recess

41

Locking teeth

42

feather

43

Die

44

Die

45

Knee lever

46

Knee lever

47

Toggle lever drive

48

Equilibrium position

49

attack

50

attack

51

Spring arm

52

Spring arm

53

Closed position

54

Carrier

55

Carrier

56

Partially open position

57

Open position

58

Locking device

59

Detent spring

60

Locking element

61

Counter-locking element

62

Detent arm

63

pen

64

deepening

65

Locking contour

66

Pivot pin

67

Coupling arm

68

Compression spring

69

Compression spring

70

Opening spring

71

Closing spring

72

Ring heel

73

Ring heel

74

Characteristic

75

Characteristic

76

Characteristic

77

Spring force

78

Opening angle

79

first partial working stroke

80

second partial working stroke

81

Working stroke

82

Pliers head

Claims (15)

1. Pressing or crimping pliers (1) comprising two pliers jaws (6, 9) which are connected by a driving connection to the two hand levers (8, 24) in a way such that it is possible to induce a working stroke (81) from an open position (57) of the pliers jaws (6, 9) into a closed position (53) of the pliers jaws (6, 9) by means of a manually induced relative movement of the hand levers (8, 24), characterised in that

   a) an equilibrium position (48) divides the working stroke into a first working stroke part (79) which is arranged between the open position (57) and the equilibrium position (48) of the pliers jaws and a second working stroke part (80) which is arranged between the equilibrium position (48) and the closed position (53),

   b) a spring device (35) is provided which interacts with the pliers jaws (6 ,9) in a way such that

   ba) the spring device (35) does not apply a force upon the pliers jaws (6, 9) in the equilibrium position (48) arranged between the open position (57) and the closed position (53) of the pliers jaws (6, 9) and

   bb) the spring device (35) applies a closing force upon the pliers jaws (6, 9) in the first working stroke part (79) being arranged between the open position (57) and the equilibrium position (48), whereas instead the spring device (35) applies an opening force upon the pliers jaws (6, 9) in the second working stroke part (80) being arranged between the equilibrium position (48) and the closed position (53).
2. Pressing or crimping pliers (1) of claim 1, characterised in that the spring device (35) comprises:

   a) a closing spring (71) which creates the closing force in the first working stroke part (79) and

   b) an opening spring (70) which creates the opening force in the second working stroke part (80).
3. Pressing or crimping pliers (1) of claim 1, characterised in that the spring device (35) comprises a spring (34) which both

   a) creates the closing force in the first working stroke part (79) as well as

   b) creates the opening force in the second working stroke part (80).
4. Pressing or crimping pliers (1) of one of the preceding claims, characterised in that

   a) at least one stop (50; 49) is provided which defines an extremal displacement of a spring base of the spring device (35) and

   b) at least one follower (54; 55) is provided,

   c) in a working stroke part (79, 80) a follower (54; 55) moves the spring base of the spring device (35) away from the stop (50; 49).
5. Pressing or crimping pliers (1) of claim 4, characterised in that

   a) the stop (49; 50) is fixed to a pliers head (82) or supported by the pliers head (82);

   b) the follower (55; 54) is fixed to a pliers jaw (9) which is moved relative to the pliers head (82) over the working stroke (81) or is formed by the pliers jaw (9).
6. Pressing or crimping pliers (1) of one of claims 3 to 5, characterised in that the spring (34) is embodied as an U-shaped bending spring or leaf spring (36).
7. Pressing or crimping pliers (1) of claim 6, characterised in that spring arms (51, 52) of the U-shaped bending spring or leaf spring (36) extend in the direction of a longitudinal axis of the pliers head (82) or in the direction of the closed hand levers (8, 24).
8. Pressing or crimping pliers (1) of one of the preceding claims, characterised in that a forced locking unit (37) is provided which secures a partially closed position of the pliers jaws (6, 9) once reached against an opening and only allows an opening of the pliers jaws (6, 9) only when the working stroke (81) has completely been run through, where when having completely run through the working stroke (81) the spring device (35) moves the pliers jaws (6, 9) into the equilibrium position (48).
9. Pressing or crimping pliers (1) of one of the preceding claims, characterised in that the open position (57) can be secured by a latching device (58) or locking device.
10. Pressing or crimping pliers (1) of claim 9, characterised in that the or a spring (34) is multifunctional because the spring (34)

    a) creates the opening force and/or the closing force and

    b) creates a latching force of the latching device (58) or a locking force of the locking device.
11. Pressing or crimping pliers (1) of claim 10, characterised in that

    a) a spring arm (52) of the or a U-shaped bending spring or leaf spring (36) supports a latching spring arm (62) of the latching device (58) and

    b) the latching spring arm (62) elastically forms or supports a latching element (60) which interacts with a latching effect with a counter-latching element (61) which is moved in the working stroke (81) relatively to the latching element (60).
12. Pressing or crimping pliers (1) of one of the preceding claims, characterised in that

    a) a fixed pliers part (2) comprises a fixed pliers jaw (6) and a fixed hand lever (8),

    b) a moveable pliers part (3) comprises a moveable pliers jaw (9) and is linked for being pivoted by a pivot bearing (13) to the fixed pliers part (2),

    c) a moveable hand lever (24) is linked for being pivoted by a pivot bearing (26) to the fixed pliers part (2) and

    d) the moveable hand lever (24) is connected via a driving connection to the moveable pliers part (3).
13. Pressing or crimping pliers (1) of claim 12, characterised in that the driving connection comprises a toggle lever drive (47).
14. Pressing or crimping pliers (1) of claim 12 or 13 when referring back to claim 11, characterised in that the moveable hand lever (24) comprises the counter-latching element (61).
15. Pressing or crimping pliers (1) of one of claims 12 to 14, characterised in that the pivot bearing (13) by which the moveable pliers part (3) is linked for being pivoted to the fixed pliers part (2) is arranged in the half of the longitudinal extension of the fixed pliers part (2) which is arranged remote from the pliers head (82).

Images