EP2905848B1 - Jointing clamp - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a pressing tongs, which is used for pressing a workpiece. For example, by means of the crimping tool, a deformation of the circumference of a workpiece or contact element, in particular a pressing in of several notches on the circumference and / or the pressing of ferrules, contact sockets or cable lugs on an electrical conductor u. ä.

STATE OF THE ART

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. Radially internal Gesenkflächen the ram form the circumferentially largely closed die, the cross-sectional area is reduced with the rotation of the pivot ring and the concomitant rotation of the ram, whereby the pressing 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 a movable hand lever is articulated on 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 blocking element a Zwangsgesperre is 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 force applied to the lever operating forces without an opening movement of the pliers head can be done. Rather, an opening movement is only possible when the pressure lever has completely completed the predetermined Gesamtpresshub.

EP 0 732 779 B1 describes the problem that basically in a pressing tongs with a Zwangsgedperre on the Zwangsgesperre an end position is predetermined, which correlates with a predetermined final size of the die. 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 crimping pliers, then crimping must always take place up to the mentioned end size of the die. Regardless of the size of the workpiece, the total pressing stroke is thus always the same, while the acting pressing forces are dependent 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 beats EP 0 732 779 B1 not rigidly support the ball stud of the pressure lever. Rather, according to EP 0 732 779 B1 the fixed hand lever in the connection area formed elastically 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 towards 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. For a larger workpiece can thus according 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 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 in EP 0 732 779 B1 also referred to as "force-displacement compensation".

Further prior art with respect to a pliers head with an actuation of more than two press dies on the rotation of a pivot ring reveal the patents DE 101 40 270 B4 and DE 10 2005 003 615 B3 , Here, the plunger are not rotatably held on the base body, but are guided radially displaceable relative to this, and wherein here a different drive kinematics for the operation of the pliers head is used.

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.

Further pressing tongs are out DE 197 09 639 A1 and DE 198 58 719 A1 known.

The publication WO 95/23048 relates to a crimping pliers, in which a forceps jaw is pivotable about a pivot joint against a forceps jaw carried by the fixed hand lever. The movable jaw is driven by a toggle lever operated by a movable hand lever. The pressure lever used in this case is interposed with a meandering course between the fixed hand lever and the movable hand lever and has an elasticity such that with applied to the hand forces actuating forces deformation of the pressure lever is possible.

The publication US 7 997 116 B2 discloses a pressing tongs in which four dies are actuated via a pivot ring. The swivel ring is in turn operated via a toggle mechanism formed with a fixed hand lever and a movable hand lever and a pressure lever. In this case, the pressure lever can be latched via a latching recesses having Langnut in different relative positions to a locking pin which is carried by the movable hand lever. Depending on the position of the locking bolt thus an effective length of the pressure lever can be influenced. The pressure lever should be elastically deformable in the compression of the hand lever. In this way, the pressure lever is to act as a spring that balances the forces between the hand levers and the dies to compensate for different dimensions of a workpiece.

OBJECT OF THE INVENTION

The invention has for its object to provide a pressing tongs with alternative or extended possibilities for the design of the pressing force-Presshub characteristic and / or with a provision of a force-displacement compensation for a pressing of workpieces with different dimensions.

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 tongs invention has a pliers head. The pliers head is formed with a base body and an actuating body. To produce a pressing movement of press dies, the actuating body is movable relative to the main body. A solid hand lever is firmly connected to the body. A movable hand lever is articulated (directly or indirectly) on the actuating body. The movable hand lever is connected via a knee joint pivotally connected to a pressure lever, which in turn is pivotally articulated to the fixed hand lever.

• der Handhebel mit zwei Handhebelteilen, welche V-förmig miteinander verbunden werden müssen und jeweils elastisch ausgebildet werden müssen und mit einer Einschnürung ausgestattet sein müssen, ausgebildet sein muss, wie dies gemäß EP 0 732 779 B1 der Fall ist,
• eine Führung des Schwenklagers für den Druckhebel in einem Langloch unter Beaufschlagung einer Spiralfeder erfolgen muss, wie dies gemäß EP 0 158 611 B1 der Fall ist, oder
• der feste Handhebel mit einer gezielten Schwächung und Verzweigung durch Einbringung eines Schlitzes ausgestattet sein muss, wie dies gemäß DE 31 09 289 der Fall ist.

The invention proposes that deviating from the prior art explained at the outset, the resilience of the drive kinematics of the pressing tongs is not ensured by the fact that a point of articulation of the pressure lever is elastically yielding on the fixed hand lever (cf. EP 0 732 779 B1 . EP 0 158 611 B1 and DE 31 09 289 C2 ), but rather the pressure lever itself is yielding. As a result of this embodiment, a simplification can be brought about compared with the embodiments known from the prior art, since it is not absolutely necessary that

• the hand lever with two hand lever parts, which must be connected to each other in a V-shape and each have to be elastic and with a constriction must be equipped, as is required EP 0 732 779 B1 the case is,
• a guide of the pivot bearing for the pressure lever must be made in a slot under the action of a coil spring, as in accordance with EP 0 158 611 B1 the case is, or
• the fixed lever must be equipped with a targeted weakening and branching by introducing a slot, as described in DE 31 09 289 the case is.

• der Länge des Druckhebels,
• des Materials des Druckhebels und dessen Steifigkeit,
• des Querschnitts des Druckhebels und dessen Querschnittsverlauf und/oder
• der Geometrie des Druckhebels

Rather, the design of the fixed hand lever is not subject to any special requirements with regard to the dimensioning of the rigidity thereof. The compliance and a force-displacement compensation according to the invention (at least) by the choice

• the length of the pressure lever,
• the material of the pressure lever and its rigidity,
• the cross section of the pressure lever and its cross-sectional shape and / or
• the geometry of the pressure lever

be given constructive. It is conceivable here that pressure levers can be used with different compliances for different pressing tongs, while other parts of the pressing tongs, in particular the fixed hand lever must not be changed. In this way, pressing tongs for different applications can be provided solely by replacing the pressure lever in the invention.

Basically, any structure of the pliers head and the actuation kinematics can be used for the crimping pliers. It is also quite possible that in the pliers head only two ram, in this case, under certain circumstances, two die halves, are present, which are held on the base body and the actuator body or integrally formed by these. For a particular application of the measures according to the invention, the crimping pliers have at least three press punches, which are mounted in such a way relative to the base body of the pliers head, that they are movable radially inwards. This movement may be a pivoting about a pivot bearing fixed to the main body (see. EP 0 732 779 B1 ) or a radial displacement (cf. DE 10 2005 003 615 B3 . DE 10 2011 052 967 B4 and DE 101 40 270 B4 ). The actuating body is formed in this case as compared to the main body rotatable pivot ring. The swivel ring has grooves or cam surfaces on, over which the pressing rams are movable radially inwardly together with a rotation of the pivot ring.

The mechanical stress of the pressure lever can be arbitrary, provided that it leads to a flexibility of the same. It is conceivable, for example, that the pressure lever is designed to be elastic in its longitudinal direction, so that upon actuation of the pressure lever, the pressure lever changes its length as a result of the acting normal tension. For a particular embodiment of the invention, the pressure lever is formed with a crank. The cranked design of the pressure lever has the consequence that acting on the articulation points of the pressure lever on the two hand levers longitudinal force, which acts in the direction of the longitudinal axis, which connects the aforementioned articulation points, not only leads to a pure stress of the pressure lever with a normal voltage. Rather, the cranked design of the pressure lever has the consequence that the pressure lever is subjected to bending, wherein the stress on bending is dependent on the extent of the crank of the pressure lever. By selecting the cross section of the pressure lever, the modulus of elasticity of the same, the course and the cranking and the area moment of inertia of the pressure lever can constructively targeted the flexibility of the pressure lever can be specified. It is also possible that by the structural specification of a buckling behavior, which results from the superposition of a stress on bending and a stress with a longitudinal force due to the crank, a specification of the compliance, u. U. up to the specification of a nonlinear compliance behavior occurs. It is also entirely possible that the resilience of the pressure lever according to the invention results from a superimposition of different mechanical stress types.

In principle, it is possible that no automatic reset of the pressing tongs takes place from an reached closed position, so that this provision must be brought about manually. If an automatic reset in the opening direction is desired, this can be done via a return spring, which acts on the hand lever directly or indirectly in the opening direction. In principle, the return spring can be arranged between any components and at any desired locations of the actuating kinematics. For a particular embodiment of the invention, a spring base of the return spring in the region of the knee joint is supported on the movable hand lever, preferably on the knee joint itself. On the other hand, the other spring base of the return spring is supported on the fixed hand lever.

It is possible that the pressing tongs is formed without a Zwangsgesperre, so that the operation of the pressing tongs increased demands on the care of the use and the user stops by observing the induced pressing stroke and / or reaching an estimated manual force the pressing process. For an advantageous embodiment, however, the pressing tongs invention is equipped with a Zwangsgesperre, whereby the careful implementation of the pressing process is guaranteed up to a defined end position. In this case, preferably according to the invention, the end position depends both on the induced relative movement of the actuating body relative to the base body, ie the total pressing stroke of the ram, as well as the elastic travel of the flexible pressure lever, wherein a constructively predetermined dependence can exist between the two influencing variables.

According to a further proposal of the invention extends through the return spring, a rod which can serve to guide the return spring and, for example, avoids that this kinks. The rod can be designed to be multifunctional in the context of the invention by this is equipped with a toothing, with which then the Zwangsgesperre may be formed. This may result in a particularly compact design and / or a reduction of the required components.

It is quite possible that extends for all possible operating position of the lever, the pressure lever between the two hand levers. A particularly compact design and an extension of the possibilities for the crank of the pressure lever and the design of the kinematics of the toggle lever mechanism results for a further proposal of the invention, according to which the movable hand lever has an open towards the fixed hand lever recess. In the open recess of the pressure lever with closure of the hand lever can occur (completely or only partially). To mention only a non-limiting example, the hand lever may be formed in the region of the pressure lever with two plates held at a distance, between which then the recess is formed, in which the pressure lever with closure of the hand lever occurs. It is also possible that the fixed lever in the region of the pressure lever forms a U-shaped cross-section, in which case the recess is formed between the two parallel legs of the U, in which the pressure lever can enter.

According to the invention, the offset of the pressure lever from the knee joint in the direction of the fixed hand lever increases, without a turning point and with a continuous increase. The central axis forms in the region of the pivot bearing, with which the pressure lever is articulated on the fixed hand lever, an angle α of at least 90 ° with the longitudinal axis of the fixed hand lever.

It is also possible that the curved center axis of the pressure lever with respect to a longitudinal axis of the pressure lever (which connects the knee joint with the pivot bearing, with which the hand lever is articulated to the fixed hand lever) a maximum distance of at least 1.5 cm, preferably at least 2 cm or at least 2.5 cm. This increases with increasing maximum distance the stress of the pressure lever with a bending moment, since the lever arm of the forces acting on the articulation points of the pressure lever forces increases with increasing the distance.

In a further embodiment of the invention, an angle between a connecting axis of the longitudinal axes of the die and the pivot bearing, in which the movable hand lever is articulated to the pivot ring, and a connecting axis of the center of the free end of the fixed hand lever and the die is greater than 50 °, in particular greater than 55 °, 60 ° or 65 °. It is entirely possible that the die formed by the press dies is located approximately centrally between the extensions of the two hand levers in the region of the pliers head. For a particular proposal of the invention, the die formed by the press dies but off-center, namely arranged in extension of the fixed hand lever. This allows the distance of the articulation point of the movable hand lever on the actuating body, in particular the pivot ring, can be increased by the die, whereby the forces transmitted via this articulation point have an enlarged lever arm, so that ultimately an increase in the pressing forces can be brought about and / / or a very compact pliers head can be created.

In a further embodiment of the invention, the distance of the pivot bearing, with which the movable hand lever is articulated on the pivot ring, from the longitudinal axis of the die 30 mm. The distance of the pivot bearing, with which the movable hand lever is articulated to the pivot ring, of the knee joint is 14.5 mm. The distance of the knee joint from the pivot bearing, with which the pressure lever articulated to the fixed hand lever is 80 mm. However, it is also possible that at least one of the distances deviates from the specified distance dimensions by a maximum of 20%, in particular not more than 10% or 5% (the deviations of the individual distances may be the same or different).

For a further proposal of the invention, the two hand levers at a distance of 30 mm from their free ends for open hand lever have a distance of 118 mm. The two hand levers have a distance of 41 mm at a distance of 30 mm from their free ends for closed hand levers. It is quite possible, however, that at least one of the distances deviates from the specified distance dimensions by a maximum of 20%, in particular not more than 10% or 5%. For this embodiment results for the different hand spans of users with different hand sizes good operability.

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". So if, for example, a return spring is mentioned, this is to be understood that exactly one return spring, two return springs or more return springs available are. 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

zeigt eine Prinzipskizze einer erfindungsgemäßen Presszange in geöffnetem Zustand.

Fig. 2

zeigt die Presszange gemäß Fig. 1 in geschlossenem Zustand.

Fig. 3

zeigt eine Draufsicht einer konstruktiven Ausgestaltung einer Presszange in geöffnetem Zustand.

Fig. 4

zeigt die Presszange gemäß Fig. 3 in geschlossenem Zustand.

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

Fig. 1

shows a schematic diagram of a pressing tongs according to the invention in the open state.

Fig. 2

shows the crimping pliers according to Fig. 1 in closed condition.

Fig. 3

shows a plan view of a structural design of a pressing tongs in the open state.

Fig. 4

shows the crimping pliers according to Fig. 3 in closed condition.

DESCRIPTION OF THE FIGURES

In the Fig. 1 and 2 a pressing tongs 1 according to the invention is shown schematically, here hidden invisible edges are shown in dashed lines. It is possible that the pressing tongs 1 is manufactured in plate construction.

The pressing tongs 1 has a pliers head 2. The pressing tongs are operated by manual operation of hand levers 3, 4, wherein between the hand lever 3, 4 and the pliers head 2 an actuating kinematics 5 is interposed, which is designed as a toggle lever drive 6.

For the illustrated embodiment, the pliers head 2 is formed with a base body 7 and an actuating body 8, which are each formed plate-shaped. For the illustrated embodiment, the actuator body 8 is formed as a pivot ring 34. The main body 7 is rigidly connected to the hand lever 3, which is why the hand lever 3 is also referred to as a "fixed hand lever". For the illustrated embodiment, the main body 7 and the hand lever 3 are integrally formed in the form of a plate, in particular as a stamped part. Opposite the main body 7 of the actuator body 8 in the plane about a Gesenkachse 9, which is oriented vertically to the plane, rotatable. The actuating body 8 has a continuous recess 10, which has a circular contour with radially outwardly extending, uniformly distributed over the circumference of grooves 11, whereby a kind of splined shaft profile is formed. For the illustrated embodiment, the actuator body 8 has six such grooves 11. Also distributed uniformly over the circumference of the Gesenkachse 9 here six pivot pins 12, whose longitudinal axes are vertical to the plane Fig. 1 are oriented and which are supported by the base body 7. Opposite the pivot pin 12 are pivotally mounted here six press dies 13 in the plane. The pressing dies 13 form a die surface 14 with a radially inwardly bevelled end face. The Gesenkflächen 14 of the ram 13 together form a substantially circumferentially around the Gesenkachse 9 closed die 15, whose cross section in the present case corresponds to a hexagon with the same side lengths. The cross-sectional area of the die 15 decreases with the pivoting of the ram 13 in a clockwise direction. In the opposite end of the die surface 14, the ram 13 are each receiving in an associated groove 11. The grooves 11 form a kind of driver for the ram 13, so that the rotation of the actuator body 8 by the contact of said end portions of the ram 13 with the grooves 11 has the common pivoting of the ram 13 with the same pivot angles result. Ultimately, therefore, with the rotation of the actuating body 8 relative to the base body 7, a reduction of the cross-sectional area of the die 15 and thus a pressing of a workpiece arranged in the die 15 take place.

• gemäß dem eingangs angeführten Stands der Technik,
• mit Betätigungsnocken anstelle der Nuten 11,
• einem Verschiebe-Freiheitsgrad der Pressstempel 13 anstelle einer schwenkbaren Führung o. a.,

The embodiment of the forceps head 2 described above and shown in the figures is chosen only as an example, wherein in the context of the present invention, other embodiments of the pliers head 2, for example

• according to the cited prior art,
• with actuating cams instead of the grooves 11,
• a shift degree of freedom of the punch 13 instead of a pivotal guide or the like,

Can be used. It is also entirely possible that the pliers head 2 is designed for fundamentally different pressing operations, for example with a different number of press dies, whereby only two press dies or die halves can be present and also one die half of the main body 7 and one die half of the operating body 8 may be formed, which are not rotated in this case relative to each other, but are mutually displaceable in the direction of a pressing stroke.

The generation of the relative movement of the actuating body 8 relative to the base body 7 via the toggle lever drive 6. For this purpose, the hand lever 4 is hinged in the pliers head 2 facing end portion with a pivot bearing 16 on the actuator body 8. The hand lever 4 is for this reason also referred to as a "movable hand lever". Slightly spaced from the pivot bearing 16, a pressure lever 18 is hinged to the hand lever 4 in a pivot bearing 17. The other end region of the pressure lever 18 is articulated in a pivot bearing 19 on the hand lever 3. The pivot bearing 17 in this case forms a knee joint 25 for a knee lever 20, which is formed by the hand lever 4 in the region between the pivot bearings 16, 17, as well as a toggle lever 21 which is formed by the pressure lever 18. The two toggle levers 20, 21 form in the open position according to Fig. 1 an obtuse angle, for example with an angle in the range of 130 °, 140 ° or 150 ° ± 10%, and approach with closing the hand lever 3, 4 of the extended position, see. Fig. 2 ,

Optionally, the pressing tongs 1 can be acted upon in the opening direction by means of a return spring 22, whereby an automatic opening of an opening movement is made possible at the end of the total stroke of the pressing tongs 1. For the illustrated embodiment, the return spring 22 acts between the hand levers 3, 4. Here, a spring base 23 is supported on the knee joint 25, while the other Federfußpunkt 24 of the return spring 22 is supported on the hand lever 3, preferably immediately adjacent the pliers head 2 or Actuator 8. Preferably, the return spring 22 is oriented approximately vertically to a longitudinal axis 37 of the hand lever 3.

For the illustrated embodiment extends through the interior of the return spring 22, which is designed here as a spiral spring, a rod 26 which is also articulated in the knee joint 25. The rod 26 has on its underside a toothing 27. With the toothing 27 of the rod 26 a Zwangsgesperre 28 is formed. The Zwangsgesperre 28 has a relative to the hand lever 3 pivotally mounted and acted upon by a spring 29 pawl 30. With closure of the hand lever slides the pawl 30 ratchet-like along the teeth 27 of the rod. If the applied to the hand lever 3, 4 hand forces temporarily reduced, the pawl 30 secures by engaging the teeth 27 of the rod 26 reached a position of the rod 26 in the Zwangsgesperre 28, whereby the position of the hand lever 3, 4 is secured and the reached closed position of the die 15 is maintained. Thus, a once achieved pressing stage can be secured. Only with a predetermined end position of the rod 26 in the Zwangsgesperre 28, the blocking effect of Zwangsgesperres 28 by suitable design of the teeth 27 and the pawl 30 is dissolved, whereby at the end of the pressing operation, an opening movement is possible. However, it will be apparent to those skilled in the art that the basic principle of the invention is not necessarily bound to the use of a positive locking mechanism, a return spring and / or the use of the rod 26.

Assuming that the hand lever 3, 4 and the pressure lever 18 (for the pressure lever 18 deviates from the assumption of the inventive design) are rigid, the closing movement of the lever 3, 4 leads to the transfer of the toggle lever drive 6 in the direction of the extended position, what As a result, the hand lever 4, via the pivot bearing 16, applies a force to the actuating body 8, which has at least one component in the circumferential direction to the die axis 9 and thus acts to close the die 15. For the said assumption of rigid components, the closed position of the pressing tongs then correlates with a fixed, predetermined end cross section of the die 15, which can lead to the problems explained at the outset. As a remedy, the invention proposes that the pressure lever 18 is designed to be yielding. This is understood as any compliance, which has the consequence that upon application of conventional hand forces on the hand lever 3, 4, a deformation of the pressure lever 18 takes place such that changed due to the deformation of the distance of the knee joint 25 of the pivot bearing 19 to a significant extent. To name just a few non-limiting examples, the distance of the knee joint 25 from the pivot bearing 19 may vary by at least 0.5 mm, at least 1 mm, or at least 1.5 mm. The inventive equipment of the pressure lever 18 with a compliance depending on

• Für ein hinreichend kleines und/oder weiches Werkstück kann die Schließung des Gesenks 15 in vollem Umfang erfolgen, ohne dass es zu signifikanten Verformungen des Druckhebels 18 kommt. Demgemäß wird die ratschenartige Verschiebung der Verzahnung 27 der Stange 26 gegenüber der Sperrklinke 30 verursacht durch die Schließbewegung des Gesenks 25.
• In einer anderen Extremüberlegung soll angenommen werden, dass in der Öffnungsstellung gemäß Fig. 1 das Gesenk 15 voll mit einem ideal starren Werkstück ausgefüllt ist. In diesem Fall kann unabhängig von der Höhe der mittels des Kniehebeltriebs 6 erzeugten und auf den Betätigungskörper 8 übertragenen Kraft kann keine relative Verdrehung des Betätigungskörpers 8 gegenüber dem Grundkörper 7 und damit keine Schließung des Gesenks 15 erfolgen. Vielmehr führt die sukzessive Erhöhung der auf die Handhebel 3, 4 applizierten Presskräfte ausschließlich zu einer elastischen Verformung des Druckhebels 18. Mit einer Verringerung des Abstands des Kniegelenks 25 von dem Schwenklager 19 nähert sich ebenfalls der Kniehebeltrieb 6 der Strecklage an und die Handhebel 3, 4 können sich aufeinander zu bewegen. Dies führt ebenfalls zu der ratschenartigen Relativbewegung der Verzahnung 27 der Stange 26 gegenüber der Sperrklinke 30. Für hinreichend große auf die Handhebel 3, 4 aufgebrachte Betätigungskräfte kann der volle Presshub durchlaufen werden und die durch das Zwangsgesperre 28 vorgegebene Endstellung erreicht werden, ohne dass eine Veränderung des Querschnitts des Gesenks 15 erfolgt. Mit Erreichen dieser Endstellung kann dann wieder eine Öffnungsbewegung erfolgen.
• Für einen realistischen Fall unter Nutzung der Erfindung wird je nach Größe des in dem Gesenk 15 angeordneten Werkstücks und dessen Widerstand gegenüber einer Deformation sowohl eine relative Verdrehung des Betätigungskörpers 8 gegenüber dem Grundkörper als auch die Verformung des Druckhebels 18 erfolgen. Für diesen Fall ergibt sich die relative Verschiebung der Verzahnung 27 der Stange 26 gegenüber der Sperrklinke 30 somit sowohl in Abhängigkeit der relativen Verdrehung des Betätigungskörpers 8 gegenüber dem Grundkörper 7 als auch in Abhängigkeit der Verformung des Druckhebels 18. Das Verhältnis der unterschiedlichen Beiträge zu dieser relativen Verschiebung hängt ab von der Größe des Werkstücks und dessen Steifigkeit: Je größer das Werkstück und je steifer das Werkstück ist desto höher ist der Anteil der Verformung des Druckhebels 18 an der relativen Verschiebung der Verzahnung 27 der Stange 26 gegenüber der Sperrklinke 30.

Design of the arranged in the die 15 workpiece (in particular, depending on the cross-section and / or rigidity of the workpiece) the following effects on a pressing process:

• For a sufficiently small and / or soft workpiece, the closing of the die 15 can be carried out in its entirety without significant deformation of the pressure lever 18 occurs. Accordingly, the ratchet-like displacement of the teeth 27 of the rod 26 with respect to the pawl 30 caused by the closing movement of the die 25th
• In another extreme consideration, it should be assumed that in the open position according to Fig. 1 the die 15 is fully filled with an ideally rigid workpiece. In this case, regardless of the height of the generated by means of the toggle lever 6 and transmitted to the actuator body 8 force, no relative rotation of the actuator body 8 relative to the base body 7 and thus no closure of the die 15 can take place. Rather, the successive increase in applied to the hand lever 3, 4 pressing forces exclusively leads to elastic deformation of the pressure lever 18. With a reduction of the distance of the knee joint 25 of the pivot bearing 19 also approaches the toggle lever drive 6 of the extended position and the hand lever 3, 4th can move towards each other. This also leads to the ratchet-like relative movement of the teeth 27 of the rod 26 relative to the pawl 30. For sufficiently large applied to the hand lever 3, 4 actuating forces of the full pressing stroke can be traversed and 28 predetermined by the Zwangsgesperre end position can be achieved without a change the cross section of the die 15 takes place. When this end position is reached, an opening movement can take place again.
• For a realistic case using the invention, depending on the size of the arranged in the die 15 workpiece and its resistance to deformation both a relative rotation of the actuator body 8 relative to the base body and the deformation of the pressure lever 18 take place. For this case, the relative displacement of the toothing 27 of the rod 26 relative to the pawl 30 thus results both as a function of the relative rotation of the actuating body 8 relative to the base body 7 and in dependence of the deformation of the pressure lever 18. The ratio of the different contributions to this relative Displacement depends on the size of the workpiece and its rigidity: The larger the workpiece and the stiffer the workpiece is the higher the proportion of deformation of the pressure lever 18 on the relative displacement of the teeth 27 of the rod 26 against the pawl 30th

For the illustrated embodiment, the pressure lever is formed in both end regions with a thickening, in the region which bearing eyes are formed for the purpose of forming the knee joint 25 and the pivot bearing 19. With a longitudinal axis 31, a connecting line between the knee joint 25 and the pivot bearing 19 is referred to. On the other hand, a center axis 32 designates a shaft which follows the contour of the pressure lever 18 and is curved here. For example, the central axis 32 denotes the axis designated in mechanics as a "neutral phase" of the bending lever loaded pressure lever 18 or a geometric cross-sectional central axis.

The pressure lever 18 has a crank 33. Starting from the toggle 25, the pressure lever 18 is initially formed almost straight or with a small curvature. The curvature increases in the direction of the pivot bearing 19 in increasing extent continuously. For the illustrated embodiment, the pressure lever 18 is roughly formed with the shape of a "hockey stick", wherein the knee joint 25 is disposed in the region of the "handle" and the pivot bearing 19 in the end of the "club surface". In view of the offset 33, a force acting along the longitudinal axis 31, which is applied by the hand levers 3, 4 to the pressure lever 18, leads to a stress on the pressure lever 18 on bending. Apart from the aforementioned thickening of the cross section of the pressure lever of the knee joint 25 in the direction of the pivot bearing 19 increases continuously.

In Fig. 2 It can be seen that for closed hand lever 3, 4, a partial section 35 of the pressure lever is arranged overlapping the hand lever 4. For example, the hand lever 4 may be formed with two parallel spaced plates, between these two plates a recess 36 is formed, in which the portion 35 of the hand lever 18 with closure of the hand lever 3, 4 can occur. Quite possible, however, is that the hand lever 36 in cross-section C-shaped or U-shaped, between the parallel legs of C or U, the recess 36 is formed, which is oriented so that with the closing movement of the section 35 in this recess 36 can occur. As in Fig. 2 to can recognize the entering into the recess 36 portion 35 may well be more than half of the pressure lever 18.

For the illustrated embodiment, the curvature of the central axis 32 is such that, at least in the Fig. 1 illustrated opening position, the angle α of the central axis in the pivot bearing 19 relative to the longitudinal axis 37 of the fixed hand lever 3 is greater than 90 °. The course of the pressure lever 18, in particular the curvature of the central axis 32 is such that a maximum distance 38 results between the central axis 32 and the longitudinal axis 31, which is for example at least 1.5 cm, preferably at least 2 cm or at least 2.5 cm ,

A connecting axis 39 of the Gesenkachse 9 and the pivot bearing 16 forms with a connection axis 43, which connects the free end of the fixed hand lever 3 and whose center with the Gesenkachse 9, an angle β. The angle β is preferably greater than 50 °, in particular greater than 55 °, 60 ° or 65 °.

Preferred geometrical conditions on a pressing tongs are in the Fig. 3 and 4 shown. Here are in the Fig. 3 and 4 hidden edges also shown. The die 15 is arranged approximately in extension of a longitudinal axis 37 of the hand lever 3. In particular, a distance 40 of the die axis 9 from the longitudinal axis 37 is a maximum of less than 8 mm, in particular less than 5 mm or 3 mm.

In the open state of the hand lever 3, 4 according to Fig. 3 have the hand lever at a distance of 30 mm from their free ends a distance 41 of 118 mm. By contrast, the corresponding distance is 42 according to Fig. 4 only 41 mm. However, it is entirely possible that one of the stated distances 41, 42 deviates from the specified dimensions by a maximum of 20%, in particular a maximum of 10% or 5%.

Furthermore, it can be seen that according to the in Fig. 3 and 4 illustrated embodiment, the metallic hand lever 3, 4 are taken in the acted upon by the user's hands areas each in a receiving body made of plastic, which are adapted in terms of contour and elasticity to the contact with the user's hands. Out Fig. 4 It can be seen that also for this embodiment, a section 35 with the closing movement of the hand lever into a recess 36 of the hand lever 4 (and the receiving body made of plastic) occurs.

In order to ensure a good translation of the hand forces in the pressing tongs 1, the angle between the connecting axis 39 and a connecting axis of the pivot bearing 16, 19 should be approximately 90 °, at least approaching the closed position of the hand lever 3, 4, said angle also ± 5 °, for example ± 3 °, can deviate from 90 °.

The pivot bearing 19 is in the lower half of the hand lever, measured from the pliers head 2, is arranged. For example, the pivot bearing 19 is at a distance of less than 7 cm, for example, less than 6 cm or a few than 5 cm, from the free end of the hand lever third

Preferably, the movement of the pivot bearing 16 during the closing movement of the hand lever (without significant deformation of the pressure lever 18) is about 5.5 mm. Here, the hand span 30 mm from the ends of the hand lever 3, 4 cover a distance of about 80 mm. From the two mentioned requirements, namely the way of the pivot bearing 16 on the one hand and the way the hand span, u. U., that preferably the distance between the pivot bearing 16, 17 is about 14.5 mm, while the distance between the pivot bearings 17, 19 is preferably 80 mm, with also deviations of ± 20%, for example ± 10% or ± 5% of These dimensions are possible.

LIST OF REFERENCE NUMBERS

1

crimping pliers

2

pliers head

3

hand lever

4

hand lever

5

activation kinematic

6

Knee lever drive

7

body

8th

operating body

9

die axis

10

recess

11

groove

12

pivot pin

13

press die

14

die face

15

die

16

pivot bearing

17

pivot bearing

18

pressure lever

19

pivot bearing

20

toggle

21

toggle

22

Return spring

23

spring base

24

spring base

25

knee

26

pole

27

gearing

28

Zwangsgesperre

29

feather

30

pawl

31

longitudinal axis

32

central axis

33

cranking

34

swivel

35

part Of

36

recess

37

longitudinal axis

38

distance

39

connecting axis

40

distance

41

distance

42

distance

43

connecting axis

Claims (13)

1. Crimping pliers (1) comprising

   a) a pliers head (2) with a base body (7) and an actuation body (8), wherein the actuation body (8) is movable relative to the base body (7) for providing a crimping movement and

   b) a fixed hand lever (3) which is fixedly connected to the base body (7) and a movable hand lever (4) which is linked to the actuation body (8),

   c) wherein the movable hand lever (4) is pivotably linked by a toggle joint (25) to a pressure lever (18) wherein the pressure lever (18) is pivotably linked by a pivot joint (19) to the fixed hand lever (3) and

   d) the pressure lever (18) comprises an elastic compliance with the effect that when applying usual hand forces upon the hand levers (3, 4), the pressure lever (18) is deformed such that due to the deformation the distance of the toggle joint (25) from the pivot joint (19) changes to a significant extend,

   characterised in that

   e) the pressure lever (18) comprises a cranking or offset (33) wherein the cranking or offset (33) of the pressure lever (18) increases continuously from the toggle joint (25) towards the pivot joint (19) and

   f) the pressure lever (18) comprises a section (35) which has an orientation parallel to a longitudinal axis of the movable hand lever (4) for closed hand levers (3, 4) or which is arranged with an overlap to the movable hand lever (4) for closed hand levers (3, 4).
2. Crimping pliers (1) of claim 1, characterised in that

   a) at least three crimping plugs (13) are movable relative to the base body (7) in radial inner direction,

   b) the actuation body (8) is formed by a pivot ring (34) being pivotable relative to the base body (7), wherein the pivot ring (34) comprises grooves (11) or cam surfaces by which with a pivoting movement of the pivot ring (34) the crimping plugs (13) are commonly moved in radial inner direction.
3. Crimping pliers (1) of claim 1 or 2, characterised in that the pressure lever (18) comprises a cranking or offset (33).
4. Crimping pliers (1) of one of the preceding claims, characterised in that a return spring (22) biases the hand levers (3, 4) in opening direction.
5. Crimping pliers (1) of claim 4, characterised in that

   a) in the region of the toggle joint (25)a spring base (23) of the return spring (22) is supported by the movable hand lever (4) and

   b) the other spring base (24) of the return spring (22) is supported by the fixed hand lever (3).
6. Crimping pliers (1) of one of the preceding claims, characterised in that a forced locking unit (28) is provided.
7. Crimping pliers (1) of claim 6, characterised in that a rod (26) extends through the return spring (22), wherein the rod (26) comprises a toothing (27), said forced locking unit (28) being formed with the toothing (27).
8. Crimping pliers (1) of one of the preceding claims, characterised in that the movable hand lever (4) comprises a recess (36) which is open towards the fixed hand lever (3) wherein the pressure lever (18) partially enters into the recess (36) with a closing movement of the hand levers (3, 4).
9. Crimping pliers (1) of one of the preceding claims, characterised in that the pressure lever (18) comprises a curved middle axis (32) which

   a) in the region of the pivot joint (19) wherein the pressure lever (18) is linked to the fixed hand lever (4) forms an angle α of at least 90° with the longitudinal axis (37) of the fixed hand lever (3) and/or

   b) comprises a maximum distance (38) of at least 1.5 cm, preferably at least 2 cm or at least 2.5 cm, from a longitudinal axis (31) of the pressure lever (18) which connects the toggle joint (25) to the pivot joint (19) by which the pressure lever (18) is linked to the fixed hand lever (3).
10. Crimping pliers (1) of one of the preceding claims, characterised in that the angle β between

    a) a connecting axis (39) of the die axis (9) and the pivot joint (16) wherein the movable hand lever (4) is linked to the actuation body (8) and

    b) a connecting axis (40) of the middle of the free end of the fixed hand lever and the die axis (9)

    is larger than 50°, in particular larger than 55°, 60° or 65°.
11. Crimping pliers (1) of one of the preceding claims, characterised in that the die (15) is located in a prolongation of the fixed hand lever (3).
12. Crimping pliers (1) of one of the preceding claims, characterised in that

    a) the distance of the pivot joint (16) by which the movable hand lever (4) is linked to the pivot ring (34) from the die axis (9) is 30 mm,

    b) the distance of the pivot joint (16) by which the movable hand lever (4) is linked to the pivot ring (34) from the toggle joint (25) is 14.5 mm and

    c) the distance of the toggle joint (25) from the pivot joint (19) by which the pressure lever (18) is linked to the fixed hand lever (3) is 80 mm

    or at least one of the distances differs from the given distances by a maximum of 20 %, in particular by a maximum of 10 % or 5 %.
13. Crimping pliers (1) of one of the preceding claims, characterised in that

    a) in a distance of 30 mm from their free ends the two hand levers (3, 4) have a distance (41) of 118 mm for opened hand levers,

    b) wherein in a distance of 30 mm from their free ends the two hand levers have a distance (42) of 41 mm for closed hand levers

    or at least one of the distances differs from the given distances by a maximum of 20 %, in particular by a maximum of 10 % or 5 %.

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