Abstract
The invention relates to crimping pliers (1). The crimping pliers comprise a spring element (7) which is located in the force flow between hand levers (3, 5) and dies (12). The spring element (7) builds a force-displacement-compensation element (8) which provides the option to be able to crimp workpieces with different cross-sectional areas with the crimping pliers (1). According to the invention, the spring element (7) which builds the force-displacement-compensation element (8) is built in the region of the pliers head (4) of the crimping pliers (1). Preferably, the spring element (7) is a spring in the shape of an arc of a circle or a spiral spring (44) which extends in circumferential direction around the die axis (13).
Claims
1. Crimping pliers for crimping a workpiece comprising: a) two drive elements, comprising a fixed hand lever and a movable hand lever, b) a pliers head comprising a first actuation element and a second actuation element which are connected by a drive mechanism and a spring element to the drive elements, c) at least two dies for crimping the workpiece, d) two spring bases, wherein d) the first actuation element comprises guidances, wherein each said guidance guides the associated die, the second actuation element comprises actuation surfaces for the at least two dies and a relative movement between the first and second actuation element results in a movement of the at least two dies relative to the guidances which is caused by the contact of the acuation surfaces with the at least two dies such that the at least two dies are actuated for crimping the workpiece between the at least two dies, e) the spring element comprises a force-displacement-compensation element and f) the spring element is arranged in the pliers head and directly linked with one of the spring bases to the movable hand lever and with the other of the spring bases to the second actuation element.
2. Crimping pliers of claim 1, wherein the spring element comprises a bending beam.
3. Crimping pliers of claim 2, wherein the spring element comprises a plate design.
4. Crimping pliers of claim 1, wherein the spring element extends in a circumferential direction around a die axis.
5. Crimping pliers of claim 4, wherein the spring element comprises a spring having the shape of an arc of a circle or a spiral spring.
6. Crimping pliers of claim 2, wherein the bending beam has a bending stiffness varying along its longitudinal axis.
7. Crimping pliers of claim 6, wherein the geometric moment of inertia of the bending beam increases from the one of the spring bases which is linked to the moveable hand lever to a cross-section of the bending beam located opposite the spring base in a circumferential direction.
8. Crimping pliers of claim 7, wherein the geometric moment of inertia of the bending beam is symmetrical to a symmetry axis which runs approximately through the one of the spring bases which is linked to the moveable hand lever and through the cross-section of the bending beam located opposite the spring base in a circumferential direction.
9. Crimping pliers of claim 1, wherein a) the actuation elements are pivoted relative to each other around the die axis, b) the at least two dies are mounted for a pivoting movement relative to the guidances and c) the relative pivoting movement of the actuation elements results in a pivoting movement of the at least two dies relative to the guidances by the contact of the actuation surfaces with the at least two dies.
10. Crimping pliers of claim 1, wherein the drive mechanism comprises a toggle lever mechanism.
11. Crimping pliers of claim 10, wherein the toggle lever mechanism comprises a roller and a guiding part, wherein over the working stroke, the roller rolls along the guiding part.
12. Crimping pliers of claim 11, wherein a) the guiding part is mounted to the drive element at which one of the actuation elements is mounted and b) the roller is mounted for being rotated to the other drive element at which the spring element is linked which is connected to the other actuation element.
13. Crimping pliers of claim 11, further comprising a second spring element which provides a contact force of the roller at the guiding part.
14. Crimping pliers of claim 13, wherein one spring base of the second spring element biases the spring element.
15. Crimping pliers of claim 1, further comprising a forced locking unit.
16. Crimping pliers of claim 15, wherein the forced locking unit comprises a toothed latching lever a) which is rotatably mounted about a pivot axis of the roller and b) of which an end region opposing the toothing for latching is connected by an elongated hole to the drive element at which the mounting part is mounted.
17. Crimping pliers of claim 1, wherein by use of a) the force-displacement-compensation due to the force-displacement-compensation element and/or b) the movement of the roller along the curved track of the guiding part with a change of the dimensional and angular properties of the toggle lever mechanism, it is possible to crimp workpieces of different cross-sectional areas, wherein for two different workpieces crimped with the crimping pliers, the cross-sectional areas differ by at least a factor of 30.
18. Crimping pliers of claim 1, wherein the pliers head further comprises a positioning device for at least one workpiece.
19. Crimping pliers of claim 1, wherein the spring element is guided by a guidance.
20. Crimping pliers of claim 2, wherein the spring element extends in a circumferential direction around a die axis.
21. Crimping pliers of claim 3, wherein the spring element extends in a circumferential direction around a die axis.
22. Crimping pliers of claim 3, wherein the bending beam has a bending stiffness varying along its longitudinal axis.
23. Crimping pliers of claim 22, wherein the geometric moment of inertia of the bending beam increases from the spring base at which the bias by the drive mechanism is applied to a cross-section of the bending beam located opposite the spring base in a circumferential direction.
24. Crimping pliers of claim 23, wherein the geometric moment of inertia of the bending beam is symmetrical to a symmetry axis which runs approximately through the spring base at which the bias by the drive mechanism is provided and through the cross-section of the bending beam located opposite the spring base in a circumferential direction.
25. Crimping pliers of claim 12, further comprising a second spring element which provides a contact force of the roller at the guiding part.
26. Crimping pliers of claim 25, wherein one spring base of the second spring element biases the spring element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) 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.
(2) FIGS. 1 to 11 show a first embodiment of the crimping pliers in an open position (FIG. 1), a closed position (FIG. 2), with components of the crimping pliers in an exploded view (FIGS. 3 and 4), with a guiding part with curved tracks in a three-dimensional single part drawing (FIG. 5), with a toggle lever angle of the crimping pliers in the open position (FIG. 6) and in the closed position (FIG. 7) and with the actuating force curves for different workpieces (FIG. 8) and with the dimensions of the spring element (FIGS. 9 and 10) and with the resulting curves for the tension in the spring element (FIG. 11).
(3) FIGS. 12 to 13 show a different embodiment of the crimping pliers wherein FIG. 12 shows the toggle lever angle of the toggle lever mechanism in an open position and FIG. 13 shows the toggle lever angle of the toggle lever mechanism in the closed position.
(4) FIGS. 14 to 21 show other embodiments of the crimping pliers.
(5) FIGS. 22 and 23 show another embodiment of the crimping pliers with an additional guidance of the spring element.
DETAILED DESCRIPTION
(6) FIG. 1 shows crimping pliers 1 in an illustration wherein one of two cover plates 2a, 2b with which a fixed hand lever 3 and a pliers head 4, in particular in a kind of housing of the pliers head 4, is built, is disassembled.
(7) The crimping pliers 1 are built with a fixed hand lever 3 and a movable hand lever 5. A pivoting of the hand levers 3, 5 towards each other (cp. the transition from FIG. 1 to FIG. 2) via a drive mechanism 6 and a spring element 7, which builds a force-displacement-compensation element 8 generates a relative movement of actuation elements 9, 10. Here, the actuation element 9 is integrally built by the part of the cover plate 2 which extends in the region of the pliers head 4 so that a fixed actuation element 9 is built. Instead, the actuation element 10 is a movable actuation element 10 in the form of a pivot ring 11 which can be pivoted relative to the fixed actuation element 9 about a workpiece axis or die axis 13 defined by dies 12. Here the die axis 13 has an orientation perpendicular to the plane of illustration according to FIG. 1. The dies 12 are pivotable about axes which have an orientation parallel to the die axis 13 and which are supported by bearing bolts 14 which are held at the actuation element 9 or the cover plate 2. The bearing bolts 14 accordingly build guidances 15 for the dies 12. At the radial inner side in the region of grooves the pivot ring 11 forms actuation surfaces 16 at which counter-actuation surfaces 17 of the dies 12 contact so that a pivoting of the pivot ring 11 about the pivot axis 13 results in a pivoting movement of the dies 12 around the bearing bolts 14. The pivoting movement of the dies 12 again has the consequence that a die contour 18 changes its size. Here, the die contour is defined by the dies 12 and closed in circumferential direction around the die axis 13 under the build-up of a minimal gap between the adjacent dies 12. For the shown embodiment the die contour 18 is hexagonal in a first approximation independent from the size of the same.
(8) The spring element 7 is built by an integral protrusion of the pivot ring 11 which extends in circumferential direction around the pivot axis 13 with the shape of an arc of a circle or here a spiral form. For the shown embodiment the circumferential angle is approximately 360. The spring base 19 building the connecting region with the pivot ring 11 as well as the outer spring base 20 of the spring element 7 are approximately located in a 4 o'clock position with respect to the die axis 13 for the illustration according to FIG. 1 wherein the fixed hand lever 3 has a horizontal orientation. The spring base 20 is pivotably liked, here by a bearing bolt 21 at the movable hand lever 5. A roller 23 is supported for being rotated at the movable hand lever 5, here by a bearing bolt 22. The roller 23 contacts a curved track 24 of a guiding part 25. In the present case, by the curved track 24 the guiding part 25 only guides the roller 23 on one side. However, for another embodiment it is also possible that the roller 23 is accommodated between two curved tracks which might be the case with some play or without any play. The guiding part 25 is rigidly fixed to the fixed hand lever 3, here by bearing bolts 26, 27. By the bearing bolt 22 also a toothed latching lever 28 is supported for being pivoted. The toothed latching lever 28 is built with lever parts 29, 30. In the outer end region the lever part 29 forms a toothing 31 for latching. The lever part 30 comprises an elongated hole 32 having an orientation radially to the bearing bolt 22. The bearing bolt 27 extends through the elongated hole 32.
(9) The drive mechanism 6 is formed by a toggle lever mechanism 33. The toggle lever mechanism 33 comprises a toggle lever 34 which corresponds to the connection between the contact point of the roller 23 with the curved track 24 and a second toggle lever 35 which corresponds to the connection between the bearing axes defined by the bearing bolts 21, 22. A toggle lever angle 36 is built between the toggle levers 34, 35.
(10) During the working stroke of the crimping pliers 1 from the open position according to FIG. 1 to the closed position according to FIG. 2, the movement of the hand levers 3, 5 in a first part of the stroke with neglectable crimping forces and with a support of the roller 23 at the curved track 24 of the guiding part 25 leads to the result that the bearing bolt 21 and therewith also the spring base 20 of the spring element 7 move in circumferential direction 37 around the die axis 13. Due to the neglectable crimping forces, there is no elastic deformation of the spring element 7. Accordingly, there is a corresponding pivoting movement of the pivot ring 19 which again coincides with a pivoting movement of the dies 12 and a reduction of the cross-sectional area of the die contour 18. Due to the fact that the contact point of the roller 13 with the curved track 24 of the guiding part 25 is not fixed, the roller 23 is able to roll along the curved track 24 during this part of the stroke. Dependent on the rolling movement of the roller 23 and on the geometry of the curved track 24, a changed toggle lever angle 36 results. This complex kinematic is superimposed by an increased elastic deformation of the spring element 7 with an increase of the crimping forces in the region of the die during closing movement. This shall be illustrated on the basis of a theoretical limit case for which it is assumed that the workpiece after a first part of the stroke (which might e.g. be formed by an empty stroke) and after a second part of the stroke (by which the workpiece is crimped with a plastic deformation of the same) the workpiece is ideally rigid in the last third part of the stroke. When reaching the ideally rigid state of the workpiece, the position of the dies 12 and the pivot ring 11 and accordingly also of the spring base 19 is also fixed. However, a further closing movement of the hand levers 3, 5 is possible in the third part of the stroke because with the further actuation of the hand levers 3, 5 the spring element 7 is elastically deformed. On the one hand side, the spring base 20 is deformed in circumferential direction 37. It is also possible that the spring base 20 is deformed in radial direction 38 of the die axis 13. Accordingly, despite of the rigid workpiece and fixed dies 12, fixed pivot ring 11 and fixed spring base 19, a rolling movement of the roller 23 along the curved track 24 takes place with the transfer of the hand levers 3, 5 into the closed state. For realistic stiffnesses of the workpiece there is a superposition of a plastic deformation of the workpiece (which becomes smaller with increasing crimping force) with an elastic deformation of the spring element 7, wherein the percentage of the elastic deformation of the spring element 7 relative to the plastic deformation of the workpiece becomes larger and larger with increasing crimping force. Accordingly, in practice in some cases there is a superposition of the second part of the stroke and the third part of the stroke.
(11) Dependent on the cross-sectional area of the workpiece to be crimped, the position of the different parts of the stroke over the working stroke of the crimping pliers 1 changes: For a large workpiece an empty stroke building the first part of the stroke (e.g. between 0% and 15% of the working stroke) is very short. A plastic deformation of the workpiece takes place in a second part of the stroke, e.g. already at the beginning of the working stroke (e.g. between 15% and 60% of the working stroke), whereas a larger third part of the stroke (e.g. between 60% and 100% of the working stroke) follows in which primarily the spring element 7 is deformed. For a smaller workpiece an empty stroke building the first part of the stroke (e.g. between 0% and 30% of the working stroke) is longer. A plastic deformation of the workpiece follows in a second part of the stroke in a later part of the working stroke (e.g. between 30% and 80% of the working stroke), whereas a smaller third part of the stroke (e.g. between 80% and 100% of the working stroke) or even no third part of the stroke follows wherein primarily the spring element 7 is deformed.
(12) At the same time with the pivoting movement of the hand levers 3, 5 towards each other, the toothed latching lever 28 is pivoted. During the pivoting movement of the toothed latching lever 28 a latching nose 39 of a latching pawl 40 which is also mounted for a pivoting movement at the hand lever 5 under the bias of a spring 93 slides ratchet-like along the toothing 31 for latching. If the hand forces applied to the hand levers 3, 5 are temporarily reduced or completely removed, the engagement of the latching nose 39 into the toothing 31 for latching blocks the opening movement of the hand levers 3, 5 and therewith also an opening movement of the dies 12. Only if the hand levers 3, 5 have completely reached the closed state, the latching nose 39 has completely passed the toothing 31 for latching so that the latching pawl 40 is able to turn over and to slide in a ratchet-like fashion during an opening movement of the hand levers 3, 5 back into its starting position (which by use of the toothing 31 for latching is only possible when having completely passed the toothing 31 for latching). A forced locking unit 48 is built with the toothed latching lever 28 and the latching pawl 40 biased by the spring 39.
(13) For the general design of crimping pliers 1 with a pivot ring 11 and the provision of a common pivoting movement of here six dies 12 by a relative rotation of the actuation elements 9, 10, reference is made to the prior art, in particular EP 0 732 779 B1 and DE 10 140 270 B4 and DE 10 2005 003 615 B3. In the present case, the hand levers 3, 5 build drive elements 41, 42 upon which the manual actuation forces are applied. It will be understood that it is also possible that the drive elements 41, 42 are biased by forces of an actuator as an electrical drive.
(14) Here, the spring element 7 is built by a type of bending beam 43. In the region of the spring base 20 force components in circumferential direction 37 and/or in radial direction 38 are introduced into the bending beam 43. These force components result in the bias of the bending beam 43 around a bending axis which has an orientation perpendicular to the plane of illustration according to FIG. 1. Here, generally also the use of a bias of the bending beam 43 by a pressing force resulting in a buckling is possible. However, preferably the bending beam 43 is biased by a pulling force in circumferential direction 37. For the shown embodiment the bending beam 43 is built by a spiral spring or a spring 44 having the shape of an arc of a circle extending in the plane of illustration according to FIG. 1. Here, the spiral spring or spring with the shape of an arc of a circle extends in circumferential direction 37 around the die axis 13.
(15) The bending beam 43 comprises a neutral fiber or longitudinal axis 45 which here has the shape of an arc of a circle or a spiral shape. The bending stiffness changes along the neutral fiber or longitudinal axis 45, in particular due to a change of the geometric moment of inertia. For the shown embodiment the design of the size of the cross-section of the bending beam 43 which determines the geometric moment of inertia is symmetrical to a symmetry axis which runs through the die axis 13 and the spring base 20. In the same way the heights and the cross-sectional area of the spring element 7 is maximal in a cross-section 47 which is located in the middle in circumferential direction between the spring bases 19, 20.
(16) In the explodes view of FIG. 3 it can be seen that the crimping pliers are built with two cover plates 2a, 2b. The two cover plates 2a, 2b build the fixed hand lever 3. On the other hand, the cover plates 2a, 2b build a kind of housing of the pliers head 4. Between the cover plates 2a, 2b the movable parts, namely the spring element 7, the pivot ring 11 and the dies 12 are accommodated. On the other hand, the bearing bolts 14 for the dies 12 are accommodated in bores 49 of the cover plates 2a, 2b.
(17) Furthermore, in FIG. 3 it can be seen that the spring element 7 and the pivot ring 11 are formed by a plate design, here with four plates. The single plates for the pivot ring 11 and the spring element 7 are built as integral parts.
(18) Differing from the embodiment shown in FIGS. 1 and 2, according to FIG. 3 the spring element optionally comprises a protrusion 50 at its outer side. A spring base 51 or a plug or stem coupled with any such spring base of another spring 52 is supported at the protrusion 52. The other spring base 53 of the other spring 52 is supported at the cover plates 2a, 2b or at the movable hand lever 5. By the other spring 52 it is possible to influence the force conditions at the crimping pliers 1 additionally to the spring element 7. Accordingly, the other spring 52 can be used for manipulating the dependency of the produced crimping force from the pivot angles of the hand levers and from the actuating force applied to the hand levers. It is also possible that by the other spring 52 the contact force of the roller 23 with the curved track 24 of the guiding part 25 is increased or provided.
(19) FIG. 4 shows the assembled basic components of the crimping pliers 1 according to FIG. 3 before being assembled with handles 54, 55 associated with the two hand levers 3, 5.
(20) According to FIGS. 3 and 4, it is possible that the crimping pliers 1 comprises a positioning device 56. For the shown embodiment the positioning device 56 comprises three alternative accommodations 57a, 57b, 57c for workpieces with differing cross-sectional areas. The positioning device 56 can be brought into different operating positions in which a respective one of the accommodations 57a (57b, 57c) is arranged with an orientation coaxial to the die axis. 13. For the shown embodiment the positioning device 65 is built with a positioning strut or a positioning disc 58 which is supported for being pivoted at the cover plates 2, here by a bearing bolt 50. The positioning strut or positioning disc 58 directly and slidingly contacts the outer side of the cover plate 2b.
(21) As shown in FIG. 5, the guiding part 25 has a fork-like shape with the formation of a slit 60 between two legs 61a, 61b. Under the provision of a relative pivoting movement the toothed latching lever 28 extends through the slit 60 of the guiding part 25 (cp. also FIG. 3). In the outer end region the legs 61a, 61b each have a bore 62a, 62b through which the bearing bolts 27 extend in the assembled state. For weight reasons the legs 61a, 61b might comprise recesses 63.
(22) In FIG. 5 it can be seen that for the shown embodiment the two legs 61a, 61b form two parallel curved tracks 24a, 24b at which the two roller 23a, 23b on both sides of the toothed latching lever 28 roll along. Furthermore, it can be seen that for the shown embodiment the curved tracks 24a, 24b comprise two concave partial regions 64, 65 between which a convex partial region 66 is located. Here, the curved track 24 has a larger inclination in the concave partial region 65 which is run through at the beginning of the working stroke than in the other partial regions of the curved track 24.
(23) By a choice of a suitable shape of the curved track 24 it can be provided that the toggle lever angle 36 of the toggle lever mechanism 33 is comparatively large during the whole working stroke. According to FIG. 6, at the beginning of the working stroke the toggle lever angle 36 is approximately 135, whereas the toggle lever angle 36 is in the range between 160 to 180 at the end of the working stroke according to FIG. 7. Preferably, the toggle lever angle 36 is during the whole working stroke always between 130 and the stretched angle of 180 which is due to a suitable shape of the curved track 24, a choice of the characteristic and geometry of the spring element as well as the dimensioning of the drive mechanism 6.
(24) FIG. 8 shows the hand forces 67 being required as a function of the actuation displacement 68 of the movable hand lever 5. Here, the curves 69 to 81 show the curves for the hand force for differing cross-sectional areas of the workpieces, namely 0.08 mm.sup.2 (69), 0.14 mm.sup.2 (70), 0.25 mm.sup.2 (71), 0.35 mm.sup.2 (72), 0.5 mm.sup.2 (73), 0.75 mm.sup.2 (74), 1.0 mm.sup.2 (75), 1.5 mm.sup.2 (76) 2.5 mm.sup.2 (77), 4 mm.sup.2 (78), 6 mm.sup.2 (79), 10 mm.sup.2 (80) and 16 mm (81). Here it can be seen that for smaller workpieces at first the starting first part of the stroke is run through with neglectable crimping forces, whereas the actual hand forces are only applied at the end of the working stroke. With increasing size of the workpiece the rising of the curves 69 to 81 is shifted towards smaller actuating displacements. In FIG. 8 it can be seen that a crimping of all of the mentioned workpieces is possible with one and the same crimping pliers 1 by controllable hand forces which are preferably smaller than 300 N.
(25) FIG. 9 shows an example for the choice of the dimensions of the spring element 7. It can be seen that the spring element spirally extends around the die axis 13 with an angle in circumferential direction of approximately 360. The effective height 82 of the spring element 7 for influencing the geometric moment of inertia is symmetrical to the symmetry axis 46 or increases from both spring bases 19, 29 in the same extent to the middle of the spring element 7 in circumferential direction between the two spring bases 19, 20. Whereas in FIG. 9 only discrete values of the heights 82 of the spring element 7 are given, FIG. 10 shows the dependency of the heights 82 from the circumferential angle 83 starting from the location in the middle between the two spring bases 19, 20.
(26) FIG. 11 shows the distribution of the tension in the spring element 7, wherein here for the same tension the same grey scale has been used. By means of the symmetric design of the spring element 7 and the choice of the heights 82 according to FIG. 10, it can be provided that the maximum of the tension in the spring element 7 remains constant along the circumference or along the longitudinal axis 45.
(27) For the embodiment shown in FIGS. 12 and 13 the toggle lever mechanism 33 is not built with a roller 23 and a curved track 24 of a guiding part 25. Instead, here (with a design of the toggle lever 35 corresponding to the embodiment explained above) the toggle lever 34 is built with a pressure lever 83. In the region of the bearing bolt 22 the pressure lever 83 builds the toggle lever joint 84. In one end region the pressure lever 83 is linked by a bearing bolt 27 to the cover plate 2. In the other end region the pressure lever 83 directly builds the toothing 31 for latching of the forced locking unit 48. Due to the use of the pressure lever 83 instead of the principle roller 23/curved track 24 in the open position according to FIG. 12 the toggle lever angle 36 is approximately 90. Starting from the open position it is not possible to immediately produce large crimping forces whereas in the closed state according to FIG. 13 a toggle lever angle of approximately 160, 165 or 170 is reached. For such a toggle lever angle 36 at the end of the working stroke it is possible to produce large crimping forces. Between the open state and the closed state the toggle lever angle 36 increases continuously when running through the working stroke (whereas for the use of the principle roller 23/curved track 24 according to FIGS. 1 to 11 dependent from the chosen contour of the curved track 24 it might also be possible that the toggle lever angle 24 at least in a partial region decreases or remains constant when running through the working stroke). This illustrates that the use of the principle roller 23/curved track 24 with a suitable design of the curved track 24 might be advantageous if it is of interest that dependent on the size of the workpiece to be crimped the real crimping should take place at the beginning of the working stroke or at the end of the working stroke. Nevertheless, the inventive design is also usable for crimping pliers without the principle roller 23/curved track 24.
(28) FIG. 14 shows another embodiment of crimping pliers 1, wherein according to the embodiment shown in FIGS. 12 and 13 a pressure lever 83 without the principle roller/curved track is used. However, here the spring element 7 (which might also be built by a spiral spring or a spring 44 in the shape of an arc of a circle) extends between the spring bases 19, 20 along the circumference around the die axis 13 not with an angle of approximately 360 but only with a circumferential angle of approximately 240 without the inventive base principle being left.
(29) FIG. 15 shows another embodiment, wherein a spring 44 having the shape of an arc of a circle extends between the spring bases 19, 20 only along a circumferential angle of approximately 90. Furthermore, the spring 44 having the shape of an arc of a circle here does not only have an orientation in circumferential direction around the die axis 13 so that in some cases a different bias of the spring 44 results. Said in simple words, in this case the spring 44 having the shape of an arc of a circle might be understood as a curved elastic strut which tangentially biases the pivot ring 11.
(30) For the embodiment shown in FIG. 16 the spring element for the spiral spring or spring 44 having the shape of an arc of a circle extends over a circumferential angle of approximately 180. Also here, instead of the principle roller 23/curved track 24 an embodiment with a pressure lever 83 is used. However, here the pressure lever 83 is not rigid but intentionally elastic so that this design builds an integration of the measures according to the non-published European patent application EP 14 154 206.8 into the crimping pliers. Also in this case the pressure lever 83 in one end region forms the toothing 31 for latching. Between the toggle lever joint 84 and the linking point of the pressure lever 83 at the cover plates 2 in a rough approximation the pressure lever has a V-shape or the pressure lever is curved or comprises the shape of a bow having an angle of the bow in the region of 150 to 180.
(31) FIG. 17 shows another embodiment of the inventive crimping pliers 1 with a pressure lever 83 which here does not comprise a toothing 31 for latching and comprises an increased extension with a direct linking of the pressure lever 83 to the two hand levers 3, 5.
(32) The embodiment according to FIG. 18 generally corresponds to the embodiment according to FIG. 12. However, here the movement of the actuation element 10 or pivot ring 12 is transferred to the dies 12 in a different way: In this case only two opposing dies 12a, 12b are provided. Also here the dies 12a, 12b are guided by guidances 15, wherein the guidance is not provided for a pivoting movement of the dies 12a, 12b but for a translational movement of the dies 12a, 12b towards each other and away from each other. The movement of the dies 12a, 12b along the degrees of freedom provided by the guidances 15 is also here caused by a contact of the actuation surfaces 16 of the pivot ring 11 with counter actuation surfaces 17 of the dies 12a, 12b. Whereas in FIG. 18 the crimping pliers 1 are shown in an open position, FIG. 19 shows the closed position of the crimping pliers 1.
(33) FIG. 20 shows an embodiment of a crimping pliers 1 without the use of a toggle lever mechanism 33. Instead, here the movable hand lever 5 is mounted for being pivoted directly at the cover plate 2 and so at the fixed hand lever 3. The spring base 20 of the spring element 7 is directly linked at an end region of the hand lever 5 protruding across the linking point of the hand lever 5 to the hand lever 3. This is here accomplished by a bearing bolt 87 of the spring element 7 which is accommodated in an elongated hole 88 of the hand lever 5.
(34) FIG. 21 shows another embodiment of the crimping pliers 1 which generally corresponds to the embodiment shown in FIGS. 1 to 11. However, here the contour of the curved track 24 has been chosen such that the contour only comprises concave partial regions 64, 65 which are connected with each other by a straight partial region 89.
(35) FIGS. 22 and 23 show another embodiment of crimping pliers, wherein FIG. 22 shows the crimping pliers in the open position with assembled cover plate and FIG. 23 shows the crimping pliers also in the open position but with disassembled cover plate. This embodiment generally corresponds to the embodiment of the crimping pliers 1 according to FIGS. 1 to 11 or FIG. 21. However, here the spring element 7 is guided in an additional guidance 90. For the shown embodiment, the guidance is provided in the region of the spring base 20. The guidance 90 is built by a guiding pin 91 held by the spring element 7. The guiding pin 91 is guided in a guiding groove or an elongated hole 92 of the cover plates 2. Preferably, the elongated hole 92 extends in circumferential direction around the pivot axis 13.
(36) For the shown embodiment the guiding part 25 is mounted to the fixed hand lever 3, whereas the roller 23 is mounted for being pivoted at the movable hand lever 5. However, it is also possible that the guiding part 25 is fixedly mounted to the movable hand lever 5, whereas the roller 23 is mounted for being rotated at the fixed hand lever 3.
(37) It is possible that within the frame of the invention the same base construction is used for crimping pliers actuated by hand and for crimping pliers actuated by an external force. However, in this case hand levers are used as the drive elements for the manually actuated crimping pliers, whereas for the crimping pliers actuated by an external force instead of the hand levers drive elements linked with an actuator will be used. To mention a simple non-limiting example, for crimping pliers actuated by an external force it is also possible that the fixed (hand) lever is shortened and supported at a fixed counter bearing, whereas a crank plug, a stem or plug or the like of an actuator is linked to the movable (in some cases also shortened) (hand) lever. In some cases crimping pliers being actuated by an external force do not comprise a forced locking unit.
(38) 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.
