Abstract:
The present invention relates to crimping pliers for crimping a work piece. The crimping pliers comprise two hand levers. The hand levers are linked with tools or dies for applying a crimping movement upon the work piece. The dies are housed in a head of the crimping pliers. A locator has a pivoting degree of freedom with respect to the head around a pivoting axis which has an orientation parallel to a main extensional plane of said head and transverse to the degree of freedom of the dies during the crimping process. The locator comprises an activating element with an extension being designed and arranged such that said extension is located in the access area of a finger of a hand of a user of said pliers gripping or contacting the hand levers.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to co-pending German Patent Application No. DE 10 2008 017 366.5 entitled “Presszange mit einem Positionierer”, filed Apr. 4, 2008. 
       FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to crimping pliers comprising a locator or positioner for positioning the work piece. The crimping pliers are used for manually pressing or crimping a work piece. 
       BACKGROUND OF THE INVENTION 
       [0003]    Crimping pliers are used for pressing or crimping a work piece in a tool or die located in a head of the crimping pliers. Such crimping pliers might be used for crimping a connector or electrical contact with an end of an electric wire, wherein an insulation might be removed from the end of the electrical wire before crimping the connector or contact upon the end. The crimping pliers might also be used as working pliers for causing a plastic deformation of the work piece, for cutting or separating parts of the work piece or for punching or stamping the work piece. 
         [0004]    Furthermore, it is known to equip crimping pliers with a locator. The locator is used for positioning the work piece relative to the head of the pliers and relative to the tool or dies. The locator guarantees the exact position of the work piece at the start of the crimping process. For one known embodiment, the locator guarantees the correct position of a connector or fitting relative to the wire end freed from the insulation. Furthermore, the locator might interact with the work piece during the crimping process. A locator might also be useful for using the crimping pliers for small work pieces. This is due to the fact that the manual positioning of a small work piece through an opening of the head of the pliers into the tool or die might be difficult or unsuitable for reaching a desired position with a desired small tolerance. When using the crimping pliers for connecting a connector, contact or fitting with a wire end, it has to be guaranteed at the start of the crimping process that both the connector and the wire end have a predetermined relative position to the tool or dies. 
         [0005]    The prior art discloses a lot of different embodiments of crimping pliers, transfer mechanisms, kinematics with different degrees of freedom for the components of the crimping pliers moved throughout the crimping process as well as embodiments for locators. All of these known embodiments might be improved by the present invention: 
         [0006]    Crimping pliers known from German Patent Application No. DE 27 18 165 A1 have a C-shaped head which is open in lateral direction. Another embodiment of DE 27 18 165 A1 shows dies or tools being moved similar to scissors. For both aforementioned embodiments, the head of the pliers extends in a plane. The pliers have a locator which is pivotable around a pivoting axis between a position for assembly and a working position. The locator comprises a nest for accommodating a work piece. The pivoting axis has an orientation perpendicular to the plane of the head. It is possible to pivot the locator into the position for assembly, introduce the work piece into the nest and pivot the locator with the work piece pinned into or housed by the nest through an open side of the head into a working position. In the working position, the work piece has a defined relative position to the tools or dies. Subsequently, the crimping process plastically deforming the work piece is continued by driving the crimping pliers, here by manually pivoting the hand levers. 
         [0007]    Another crimping pliers is distributed by the applicant of the present patent application with the label CS20KS, see  FIG. 1 . The crimping pliers comprise a C-shaped head being open in one lateral direction. The head comprises a locator having a linear degree of freedom along a shaft fixed at the head, wherein the shaft follows the horizontal leg of the C. Furthermore, the shaft has an orientation parallel to the plane of the head of the pliers. The locator is driven by a lever pivotably linked with the head of the pliers. The pivoting movement of the lever is transferred by a connection between a pin guided in an elongated hole into a linear movement along the shaft. 
         [0008]    Furthermore, crimping pliers distributed by the applicant of the present patent application under the label CS25KS (see  FIG. 2 ) comprise a C-shaped head. Here, a locator is pivotably linked with the head having a pivoting axis with an orientation perpendicular to the plane of the head. A pivoting movement of the locator is caused by manually rotating a knurled disc for transferring the locator from a position for assembly to a working position. As shown in  FIG. 2 , a pivoting movement of the locator requires a manipulation of the crimping pliers with both hands of the user, wherein one hand of the user grips the crimping pliers at the hand levers, whereas the other hand of the user causes the pivoting movement of the locator. 
         [0009]    German Patent No. DE 198 32 884 C1 corresponding to U.S. Pat. No. 6,155,095 discloses crimping pliers having a head built with metal plates. Here, the head is  0 -shaped without an opening in one lateral direction. Caused by an activation of hand levers a movable part or die is moved along a longitudinal axis of the crimping pliers relative to a fixed part of the tool or die. The document discloses a locator being pivoted around a pivoting axis which has an orientation parallel to the plane of the head of the pliers and transverse to the direction of movement of the parts of the tool or dies of the crimping pliers. In a working position, the locator has an orientation parallel to the plane of the head. The locator is pivoted around the pivoting axis from a working position into a position for assembly. The activation of a pivoting movement of the locator requires both hands of a user of the crimping pliers. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention relates to a locator having a pivoting degree of freedom with respect to the head of the pliers around a pivoting axis. The pivoting axis has an orientation parallel to the plane, wherein the head of the pliers mainly extends. Furthermore, the pivoting axis has an extension transverse to the relative degree of freedom of parts of the tool or the dies of the crimping pliers. Accordingly, it is possible to pivot the locator “away” from the plane of the head of the crimping pliers. 
         [0011]    The inventive design might be used for C-shaped heads as described above. However, the aforementioned degree of freedom of the locator is also useful for heads of crimping pliers having other shapes than C-shapes. This is due to the fact that it is not necessary to move the locator through the opening of the C as known from DE 27 18 165 A1 and the crimping pliers of the applicant distributed under the labels CS20KS and CS25KS. 
         [0012]    For the inventive crimping pliers, the locator is linked with an activating element that directly or indirectly causes the pivoting movement of the locator relative to the head by manual manipulation by the user. The activating element has a design and orientation such that it is possible to manipulate the activating element by the hand of a user that at the same time grips or contacts the hand levers. Accordingly, the inventive crimping pliers might be manipulated by one single hand of the user. This is in particular of advantage in cases of another hand of the user being needed for holding the or another work piece and introducing the or another work piece into the crimping pliers. 
         [0013]    Also the crimping pliers of the applicant distributed under the label CS20KS could be manipulated by one single hand with the thumb of the user causing the movement of the locator. However, the path of the thumb for causing a movement of the locator for this known prior art increases with a closing movement of the hand levers. Instead, according to the invention, the pivoting axis has another orientation leading to a different degree of freedom of the locator. The inventive orientation leads to the result that the path of a finger of the user for activating the activating element is less dependent or independent on the relative position of the hand levers. Furthermore, it might be possible to activate the activating element by an index finger which is not possible for the crimping pliers CS20KS. 
         [0014]    Furthermore, the crimping pliers CS20KS require a complex activating mechanism with a pivotable lever and a transmission system for converting the pivoting movement into a linear movement. 
         [0015]    According to another embodiment of the invention, the activating element is built with an arm or extension of the locator, wherein such arm or extension might have a simple design. The dimensions of the arm, in particular the length of the arm, and the contour of the arm might be adapted for providing good haptics and a good accessibility of the activating element. 
         [0016]    According to one example, the arm might be built by a metal sheet, wherein such metal sheet might be curved, cranked, twisted for providing a desired geometry and activating surfaces for a finger of the hand of the user. 
         [0017]    According to another embodiment of the invention, the arm has a multifunctional design. For this embodiment, the arm is firstly used for applying a force or moment for pivoting the locator. Furthermore, the arm serves as a support for a spring element, wherein the spring element might serve for biasing the locator versus a position, in particular the working position. 
         [0018]    For another embodiment of the invention, the hand levers are moved in a plane during the crimping process, wherein the aforementioned plane might be the plane of the head or parallel to the plane of the head. In the working position of the locator, the arm has an angle smaller than 90° with respect to the aforementioned plane. For transferring the locator from the working position into another position, in particular the position for assembly, the arm is pivoted versus the plane of the head of the pliers or the plane, wherein the hand levers are moved. Such pivoting movement might be caused by the index finger or the middle finger of a hand that contacts or grips the crimping pliers. 
         [0019]    For another embodiment of the invention, the locator is secured in the working position by a resting unit, locking unit or latching mechanism. 
         [0020]    In this context, a resting unit describes a unit building a stable equilibrium for the working position. Accordingly, the resting unit keeps or restores the locator in the working position for small forces acting upon the locator or the arm. Instead, for larger forces acting upon the arm or the locator, the locator might be moved away from the working position. Examples of suitable resting units are spring biased resting elements that engage a resting groove in the working position. The dimensioning of the force level secured by the resting unit might be done by the choice of the diameter of the resting sphere, the geometry of the contour of the resting groove and/or the stiffness of a spring supporting the resting sphere. However, it is also possible to use a resting pin instead of the resting sphere. Furthermore, it might be useful to use a permanent magnet as a part of the resting unit, wherein the force of the permanent magnet determines the resting force in the working position. 
         [0021]    Instead, in the present context, a locking unit is a unit that secures the working position so that it is not possible to move the locator out of the working position solely by applying forces in the direction of the pivoting degree of freedom. A locking unit secures the working position (with or without play) by positive locking, e.g. by use of a locking bolt or a pawl. It is possible to release the locking unit with the hand holding the crimping pliers or with the other hand of the user. 
         [0022]    The present invention also covers embodiments wherein the locator is secured in another position than the working position, e.g. the position for assembly, by means of a resting unit or a locking unit. 
         [0023]    The pivoting angle of the locator relative to the head of the crimping pliers might be limited by the joint of the locator at the head or a stop element. Furthermore, it is possible that the pivoting angle might be limited by the arm or extension so that the arm has another function additional to the function of transferring activation forces and/or supporting the spring element. 
         [0024]    For one embodiment, the arm or extension is designed and arranged such that the pivoting angle is limited by the arm or extension abutting another component of the crimping pliers. 
         [0025]    According to another embodiment of the crimping pliers, the activating element, in particular the arm or extension, is designed and arranged such that it is possible to activate the activating element when gripping the hand levers with the right hand of the user with a finger of the right hand of the user. Furthermore, for the same crimping pliers it is possible to grip the hand levers with the left hand of a user and activate the activating element with a finger of the left hand. Crimping pliers according to this embodiment might be used by a left-hander or right-hander or by the same user in different work areas. Another embodiment of the invention suggests providing a modular locator for the crimping pliers. The locator and/or the arm or extension might build a variant that is optionally combined with other components of the crimping pliers. Accordingly, it is possible to manufacture, distribute and use crimping pliers related to a first group of crimping pliers having no locators, arms or extensions. Crimping pliers related to a second group are equipped with the additional module with the locator, arm and/or extension, so that the crimping pliers related to the second group might be used with an increased comfort. However, it is also possible that existing crimping pliers having no locator are adapted or subsequently equipped with a locator or an activating element. 
         [0026]    The locator with the pivoting axis having the mentioned orientation might be used for crimping pliers having a C-shaped open head or a ring-shaped closed head as described. The inventive features might additionally be used irrespective on
       the type of drive of the crimping pliers used,   the type of activating mechanics and kinematics and   the type of movement of the parts of the tool or dies relative to each other.       
 
         [0030]    Instead, according to the invention the proposed positioner is suitable for any type of crimping pliers. It is also possible to transfer one and the same locator from first crimping pliers to second crimping pliers dependent on the needs of the user. 
         [0031]    Furthermore, caused by the chosen orientation of the pivoting axis, it is also possible to design the locator independent on the number and positions of the nests or dies at the head of the crimping pliers. 
         [0032]    Furthermore, it is possible to increase the number of the nests or dies that might be used in connection with a locator. The number of nests or dies might correlate with the number of nests for the work piece at the locator. 
         [0033]    Another possible advantage of the inventive locator is that the locator comprises an increased accessibility in the position for assembly so that the preparation and the use of the crimping pliers is eased. The invention could also be used for crimping pliers wherein the movable part of the tool or die is guided on a linear path or a curved or circular path in the head of the crimping pliers. 
         [0034]    Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and the detailed description. It is intended that all such additional features and advantages be included herein within the scope of the present invention, as defined by the claims. ### 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0035]    The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. In the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0036]      FIG. 1  shows a head of crimping pliers distributed by the applicant of the present patent application in Germany under the label CS20KS. 
           [0037]      FIG. 2  shows a head of other crimping pliers distributed by the applicant of the present patent application in Germany under the label CS25KS. 
           [0038]      FIG. 3  shows crimping pliers known from DE 198 32 884 C1 having a ring-shaped closed head. 
           [0039]      FIG. 4  shows a cross-section along section IV-IV in  FIG. 3  through the head, wherein the sectional view shows a locator. 
           [0040]      FIG. 5  is a sectional view of a pivoting plate of the locator along section V-V in  FIG. 3 . 
           [0041]      FIG. 6  is a sectional view of a fixing plate of the locator. 
           [0042]      FIG. 7  is a view similar to  FIG. 4  showing the pivoting plate in an open state for providing a position for assembly. 
           [0043]      FIG. 8  is a view similar to  FIGS. 4 and 7  showing the pivoting plate pivoted in a working position. 
           [0044]      FIG. 9  is a three-dimensional view of crimping pliers according to the invention showing a pivotable locator having an arm in a working position. 
           [0045]      FIG. 10  is a view of the crimping pliers of  FIG. 9  with a scale enlarged with respect to  FIG. 9 . 
           [0046]      FIG. 11  is a three-dimensional view of the crimping pliers according to  FIGS. 9 and 10  in a position for assembly. 
           [0047]      FIG. 12  is a view according to  FIG. 11  with an enlarged scale. 
           [0048]      FIG. 13  is a three-dimensional view of an arm or extension appropriate for crimping pliers according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0049]    Referring now in greater detail to the drawings,  FIG. 3  shows crimping pliers  1  having a ring-shaped closed head  2  built with plates, i.e. two cover plates  3  and  4  with identical shapes. The cover plates  3  and  4  are arranged symmetrically to the plane  5  ( FIG. 4 ) of the head of the pliers. Plane  5  is defined by the two main directions of the extension of the head  2 . In  FIG. 3  the plate  5  corresponds to the drawing plane. 
         [0050]    Two parts  6 ,  7  building a tool are located in the head  2 . Part  6  is fixed at head  2 , whereas part  7  is linked with the head  2  providing a degree of freedom for relative movement with respect to head  2 . For the shown embodiment, the movable part  7  is guided along a linear path by means of the frame-like closed cover plates  3 ,  4 . The parts  6 ,  7  might build a pair of dies used for plastically deforming a work piece  8  throughout a crimping process. Such deformation might be used for providing a crimping connection. Before starting the crimping process the work piece  8  has to be brought into a well defined relative position to the parts  6 ,  7 . This is done by a locator  9  or positioner pivotably linked with the head  2  by a pivoting link  10  providing a pivoting movement around the pivoting axis  11 . The pivoting link  10  is designed and arranged such that the pivoting axis  11  is located in a plane  12  having an orientation parallel to the plane  5  of the head of the pliers ( FIG. 4 ). Usually plane  12  has some distance from the plane  5 . However, it is also possible that planes  5 ,  12  are one and the same plane. 
         [0051]    The locator  9  comprises a fixing plate  13 . The fixing plate  13  is fixed by a screw at one part of head  2 . Such part is connected both with the movable part  7  and with a drive  15 . The drive  15  might be built with two hand levers  16 ,  17 , wherein the hand levers are pivotably linked with each other at the head  2 . The hand levers drive the movable part  7  linearly versus the fixed part  6 . 
         [0052]    The locator  9  also comprises a pivoting plate  18 . The pivoting plate  18  is linked for a pivoting movement with the fixing plate  13  via a pivoting link  10 . Accordingly, it is possible to pivot the pivoting plate  18  around the pivoting axis  11  (see  FIGS. 7 and 8 ). 
         [0053]    The pivoting plate  18  ( FIG. 5 ) comprises at the side facing away from the plane  5  a protruding bolt  19  used for facilitating a gripping of the pivoting plate  18  when pivoting the pivoting plate  18  around the pivoting axis  11 . On the other side facing the plane  5 , the pivoting plate  18  comprises a nest  20 .  FIG. 3  shows three nests  20  located one besides the other at the locator  9  or the pivoting plate  18 . The nests  20  correlate with three dies built at the parts  6 ,  7 , whereas the different nests and dies are used for work pieces  8  having different diameters. Each nest  20  is built by a recess of the rear side  21  of the pivoting plate  18 . However, it is also possible that the nest  20  of the locator  9  or the pivoting plate  18  is built by a protrusion, in particular a protruding pin for pinning up a sleeve-like or tube-like work piece  8 . 
         [0054]      FIG. 5  is a sectional view of the pivoting plate  18  of the locator  9 . The pivoting plate  18  might be manufactured by molding or die-forming and might be built from plastic or metal. The pivoting plate  18  in the lower region comprises a plurality of protrusions  22  having recesses  23  with an open cross-section for releasably pinning the pivoting plate  18  upon a bolt  24  linked with the fixing plate  13  ( FIG. 6 ). In the assembled state the bolt  24  and the recess  23  with the open cross-section have a coaxial pivoting axis  11 . A permanent magnet  25  is located in the lower part of the rear side  21  of the pivoting plate  18 . The permanent magnet  25  is used for releasably securing a working position (see  FIGS. 4 and 8 ). It is of advantage to release the secured working position of the pivoting plate  18  in case of the work piece  8  being dilated throughout the crimping process. Accordingly, it is possible that the pivoting plate  18  is slightly pivoted with a dilation of the work piece  8  throughout the crimping process, wherein the pivoting plate  18  does not apply large axial forces upon the work piece  8 . The permanent magnet  25  providing a coupling force between the pivoting plate  18  and the fixing plate  13  might also be located at the fixing plate  13 . Also the fixing plate  13  might be manufactured by molding or pressing from plastic or metal. A bore  26  might be provided engaging a pin  27  made of steel in the assembled state ( FIG. 4 ), wherein the pin  27  cooperates with the permanent magnet  25 . The pin  27  is additionally used for fixing the fixing plate  13  together with the screw  14  against a pivoting movement at the head  2 . Instead of the use of a permanent magnet  25  (or additionally to such a permanent magnet  25 ) the pivoting plate  18  might be provided with one or a plurality of protrusions  28  at its rear side  21  that in the working position engage in, lock with or latching with bores of the fixing plates  18  (not shown in the figures). Such additional locking, latching or resting might be used for avoiding a play of the pivoting link  10  in the working position which might build up and increase when again and again using the locator  9 . Furthermore, the locking, latching or resting serves for stabilizing the working position of the locator  9  or the pivoting plate  18  for introduced work piece  8 . 
         [0055]    It is possible to pivot the pivoting plate  18  from a position for plugging on or for assembly ( FIG. 7 ) into a working position ( FIG. 8 ) with a pivoting angle  29  around the pivoting axis  11  of the pivoting link  10 . The pivoting angle  29  should be equal to or larger than 75°. In particular the present invention suggests a pivoting angle  29  of more than 90°, e.g. approximately 120° as shown in  FIG. 5 . The pivoting angle  29  is limited by a stop element  30  which is built by cover plate  3 . At the end of the pivoting movement (so in the position for assembly shown in  FIG. 7 ) an outer region or edge of the pivoting plate  18  abuts the stop element  30 . The stop element  30  at the same time builds a counter element for the pivoting plate  18  for fixing the pivoting plate  18  in the position for assembly ( FIG. 7 ). In such position, the work piece  8  might be introduced at the exact position and orientation into a chosen nest  20 . 
         [0056]    The plugging on or introduction of the work piece  8  into the chosen nest  20  is done by hand, wherein the work piece  8  might be held between and guided by the thumb and the index finger.  FIG. 7  shows a connector building the work piece  8 . Such connector is used for building a crimping connection with an electrical wire. Usually an insulation of the electrical wire has been removed before starting the crimping process. Furthermore, it is possible to provide two separate crimping connections throughout one single crimping process, namely a crimping connection with the insulation of the electrical wire and another crimping connection of the connector with the metal core of the electrical wire. 
         [0057]      FIG. 8  shows the positions of the relevant components at the start of a crimping process. The pivoting plate  18  of the locator has been pivoted with a pivoting angle  29  from the position for assembly according to  FIG. 7  into the working position according to  FIG. 8 . The work piece  8 , here a connector, has been positioned in the exact position relative to the movable part  7 . The longitudinal axis of the work piece  8  and the axis of the movable part  7  are aligned with each other. As can be seen from  FIGS. 7 and 8 , the longitudinal axis of the work piece  8  is positioned from one side of the head  2  in an orientation perpendicular to the plane  5  in the working position. From the other side of the head  2  an electrical wire  31  with the insulation removed from the metal core  32  is introduced into the head  2  until the front surface of the insulation  33  abuts a stop element  34 . The stop element  34  might be built by a thin plate being movable in the head  2  against the force of a spring. The stop element  34  serves for finding the predetermined position of the electrical wire in the head  2 . However, the stop element  34  is without any interrelation with the positioning of work piece  8  in the head  2  in the working state. The position of the stop element  34  correlates with the position of the work piece  8  in the working position. As can be seen from  FIG. 8 , the axes of the work piece  8  or the nest  20  and the electrical wire  31  are parallel but have a distance from each other in an open state of the hand levers  16 ,  17 . Throughout the crimping process, the movable part  7  with the locator  9  and the pivoting plate  18  is moved along a straight path in upper direction versus the fixed part  6 . Accordingly, the side elements or cramps of the connector or work piece  8  are passed around the metal core  32  as well as around the insulation  33 . Throughout the crimping process both of the aforementioned connections are closed. At the end of the crimping process, the electrical wire  31  is connected with the work piece  8 . The wire  31  with the work piece  8  remains in the final relative position to the movable part  7  when opening the crimping pliers so that the unit built with the wire  31  and the work piece  8  might be removed from the crimping pliers in opposite direction to the direction used before for introducing the electrical wire  31 . After returning the pivoting plate  18  of the locator  9  back into the position for plugging on or assembly according to  FIG. 7  the next work piece  8  might be introduced and the crimping process might be repeated. The described embodiment according to  FIGS. 3 to 8  (as well as other embodiments that might be combined with the features according to the invention) is disclosed in DE 198 32 884 C1. 
         [0058]      FIGS. 9 to 12  show an embodiment of inventive crimping pliers, wherein components corresponding to the embodiment of  FIGS. 3 to 7  are labeled with the same reference numerals but additional letters a. 
         [0059]    For the inventive embodiment, the locator  9   a  comprises an extension or arm  35  which is shown as a single component in  FIG. 13 . For the shown embodiment, the arm  35  is built by a formed metal sheet having a constant thickness and building a bar or flap  37  extending from the connecting region  36 . The bar or flap  37  is plain or flat with a U-shaped outer contour. The bar or flap  37  builds with the plane  5  an angle  41  smaller than 90°, wherein the angle  41  might be between 60° and 85°, in particular 70° to 80°, e.g. approximately 75°. The connecting region  36  is built by a band or bar having a constant width and being angled forming an U-shape with a base leg  38  and two parallel side legs  39 ,  40 . The base leg  38  comprises an approximately half-circular recess  42  as well as two recesses  43 ,  44 . The recesses  43 ,  44  might be opened or closed (see  FIG. 12 ) in their cross-sections. The side legs  39 ,  40  have extensions in downward direction being built by rod-like protrusions  45 ,  46 . The protrusions  45 ,  46  are angled towards each other by an angle of  900  in the end regions  47 ,  48  located opposite to the side legs  39 ,  40 . In the assembled state, the end regions  47 ,  48  are aligned with the pivoting axis  11   a - 11   a.    
         [0060]    The arm  35  is brought into contact with the locator  9   a,  wherein the bolt  19  is introduced into the recess  42  coming into contact with the outer side of the locator at the rear side of the base leg  38 . The side legs  39 ,  40  of the arm  35  laterally encompass the locator  9 a. As can be seen from  FIG. 10 , the arm  35  is fixed at the locator  9   a  by screwing two screws  49 ,  50  through the recesses  43 ,  44  into screwed bores of the locator  9   a.  The end regions  47 ,  48  serve for holding a spring element  51 , here a coiled spring or leg spring. The spring element  51  comprises two legs. These two legs are pivoted versus each other for producing a torsional moment of the spring element  51 . A first leg  52  extends parallel to the protrusion  46  in upper direction and extends into a bore  53  in the side leg  40  for securing the arm  35  in the angled end region. The other leg of the spring element  51  is supported by the crimping pliers la (not shown), e.g. at the cover plate  3   a,  the fixing plate  13   a  or the head  2   a.  The spring element  51  is pre-stressed such that the spring element  51  biases the locator  9   a  with arm  35  versus the working position shown in  FIG. 10  and secures the locator  9   a  and arm  35  in the working position. Additionally, the working position might be secured by means of the permanent magnet  25 . 
         [0061]    As shown in  FIG. 10 , the bar or flap builds an angle between approximately 60° to 80°, e.g. 70° to 80°, in particular approximately 75° with the plane  5   a,  wherein the bar or flap  37  is slightly inclined versus the hand levers  16   a,    17   a.  A user when gripping or contacting the hand levers  16   a,    17   a  with a hand is able to apply an activation force upon the bar or flap  37  with a finger, in particular the index finger or middle finger. The finger applies such force from the outer side in inner direction versus the head  2 . Accordingly, the bar or flap  37  might be used with a one-hand operation as an activating element  54  by the user. By one-hand operation the user is able to apply a force and a moment upon the locator  9   a  for pivoting the locator  9   a  from the working position according to  FIG. 9  into a position for plugging on or for assembly according to  FIG. 11 . When reducing or removing the activating force applied by the user, the spring element  51  closes the locator  9   a  by pivoting the locator  9   a  back into the working position. The pivoting movement might be limited for determining the position for plugging on or for assembly (differing from the embodiment shown in  FIGS. 3 to 7 ) by a contact of the bar or flap  37  with another element of the crimping pliers  1   a,  e.g. a part of the drive unit  17  or the pivoting bolt of the drive unit  17 . The end regions  47 ,  48  build supports  55 ,  56  for the spring element  51 . 
         [0062]    Many variations and modifications may be made to the preferred embodiments of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of the present invention, as defined by the following claims.