Hydraulically actuatable crimping device, method for carrying out a crimping operation, method for producing an electroconductive compression joint, electroconductively crimped compression sleeve, method for clamping a workpiece and hydraulic device

Abstract

A handheld hydraulically actuatable crimping device includes a hydraulic piston that can be displaced in a cylinder against the force of a spring. The piston is connected to a crimping part by a piston rod in order to carry out a crimping operation. The piston includes first and second partial pistons with first and second partial application faces which can be acted upon with hydraulic medium that has the same hydraulic pressure. Both partial pistons are respectively connected to a first and a second crimping part. The second crimping part can at a greater traveling distance only be acted upon with the second partial piston. The second crimping part can be acted upon with both partial pistons over a first partial traveling distance that is defined by the displacement of the first partial piston from its initial position up to the point, at which it reaches a stop. The first crimping part is axially covered in its entirety by the second crimping part.

Claims

1. A handheld hydraulically actuatable crimping device comprising: a hydraulic cylinder defining a longitudinal cylinder axis; a pull-back spring mounted within the hydraulic cylinder; a hydraulic medium within the hydraulic cylinder; a hydraulic piston displaceable within the hydraulic cylinder between a starting position and an end position and coaxial to the longitudinal cylinder axis against the force of the pull-back spring, the hydraulic piston including a first partial piston having a first partial application face configured to generate a compressive force due to the action of the hydraulic medium under hydraulic pressure acting upon the first partial application face, a first crimping part connected to the first partial piston, a second partial piston having a second partial application face configured to generate a compressive force due to the action of the hydraulic medium under hydraulic pressure acting upon the second partial application face, the first and second partial application faces being acted upon with the hydraulic medium with the same hydraulic pressure from the starting position to the end position, and a second crimping part connected to the second partial piston; and a stop provided in the hydraulic cylinder, wherein the second crimping part can be acted upon with both partial pistons over a first traveling distance that is defined by a displacement of the first and second partial pistons from the starting position to a point where the first partial piston contacts the stop, and wherein the second crimping part can further travel at a second traveling distance after completion of the first traveling distance when the second crimping part is further acted upon by the second partial piston without further moving the first partial piston.

2. The crimping device according to claim 1, wherein the first and second partial pistons telescope relative to each other.

3. The crimping device according to claim 1, wherein the first partial piston forms a second hydraulic cylinder for the second partial piston.

4. The crimping device according to claim 1, wherein the first partial application face defines a first size, and the second partial application face defines a second size, wherein the first size is smaller than the second size.

5. The crimping device according to claim 1, wherein the pull-back spring comprises a first pull-back spring and a second pull-back spring, wherein the first partial piston is acted upon by the first pull-back spring and the second partial piston is acted upon by the second pull-back spring.

6. The crimping device according to claim 1, wherein the first and second crimping parts comprise a crimping die.

7. The crimping device according to claim 1, wherein the first crimping part defines an outermost radial extent and the second crimping part defines an outermost radial extent which is radially outwardly of the outermost radial extent of the first crimping part.

8. A method configured to produce an electroconductive compression joint comprising: providing a compression sleeve, the compression sleeve having a constant inside diameter over its length; providing a crimping device, the crimping device comprising a hydraulic cylinder defining a longitudinal cylinder axis, a hydraulic medium within the hydraulic cylinder, a first partial piston having a first partial application face configured to generate a compressive force due to the action of the hydraulic medium under hydraulic pressure acting upon the first partial application face, the first partial application face defining a first size, a first crimping part connected to the first partial piston, a second partial piston having a second partial application face configured to generate a compressive force due to the action of the hydraulic medium under hydraulic pressure acting upon the second partial application face, the second partial application face defining a second size, and a second crimping part connected to the second partial piston, the first size being smaller than the second size, the hydraulic cylinder having a stop; providing a first cable and a second cable, each cable having a diameter, wherein the first cable has a smaller diameter than the diameter of the second cable; crimping an end region of the first cable with a first compressive force to a first location of the compression sleeve using the crimping device by moving the second crimping part over a first traveling distance that is defined by a displacement of the first and second partial pistons from an initial position to a point where the first partial piston contacts the stop, wherein the first and second partial pistons are acted upon by the hydraulic medium having the same hydraulic pressure; crimping an end region of the second cable to a second location of the compression sleeve using the crimping device by moving the second crimping part over the first traveling distance and further by moving the second crimping part over a second traveling distance by only moving the second partial piston without moving the first partial piston, the second location being adjacent to the first location over the length of the compression sleeve; wherein the first compressive force is lower than the second compressive force; and wherein the first and second cables are crimped to the sleeve at locations that lie adjacent to one another over the length of the compression sleeve.

9. A method configured to clamp a workpiece comprising: providing a hydraulic crimping device comprising a hydraulic cylinder, hydraulic medium within the hydraulic cylinder, a first clamping part in the hydraulic cylinder, a second clamping part in the hydraulic cylinder, a first partial piston in the hydraulic cylinder and connected to the first clamping part, a second partial piston in the hydraulic cylinder and connected to the second clamping part, a first pull-back spring in the hydraulic cylinder and configured to act on the first partial piston, a second pull-back spring in the hydraulic cylinder and configured to act on the second partial piston, the first and second partial pistons configured to be displaced relative to one another in a telescoping fashion in the hydraulic cylinder against the force of the pull-back springs to move the first and second clamping parts; simultaneously moving the first and second partial pistons and the first and second clamping parts by acting on the partial pistons with hydraulic medium wherein the second clamping part is moved telescopically ahead of the first clamping part to a clamping position to clamp the workpiece, and wherein only the second clamping part contacts the workpiece in the clamping position; and stopping the partial pistons in the clamping position; wherein the second clamping part and the second partial piston elastically yield or elastically follow the workpiece during a movement of the workpiece due to the connection of the second clamping part to the first and second partial pistons and as a result of a pressure compensation which takes place via the hydraulic medium because the first partial piston springs back under action of its pull-back spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in greater detail below with reference to the attached drawings that, however, merely show an exemplary embodiment.

(2) In these drawings:

(3) FIG. 1 shows a perspective view of a crimping device;

(4) FIG. 2 shows a view relating to a narrow side;

(5) FIG. 3 shows a view relating to a broad side;

(6) FIG. 4 shows a cross section through the crimping device in the upper region with a large workpiece inserted therein;

(7) FIG. 5 shows an illustration according to FIG. 4 during a displacement of the partial piston until initial contact with the workpiece takes place;

(8) FIG. 6 shows the crimping device according to FIG. 4 when the maximum compressive force is reached;

(9) FIG. 7 shows an illustration according to FIG. 4, however, with a small workpiece;

(10) FIG. 8 shows the crimping tool with inserted workpiece according to FIG. 7 after a displacement of the partial pistons until initial contact with the workpiece takes place;

(11) FIG. 9 shows an illustration of the crimping tool with workpiece according to FIG. 7 when the maximum compressive force is reached;

(12) FIG. 10 shows an illustration of the hydraulic device in a clamping position referred to a workpiece;

(13) FIG. 11 shows a cross section through a compression sleeve and inserted electrical conductors with larger and smaller diameters;

(14) FIG. 12 shows the compression sleeve according to FIG. 11 after a crimping operation; and

(15) FIG. 13 shows a top view of the crimped compression sleeve according to FIG. 12.

DETAILED DESCRIPTION

(16) A crimping device 1 in the form of a hand tool is illustrated in the figures and described below. The crimping device 1 has a handle region 2 with a length that is approximately adapted to the width of a hand. A control switch 3 is assigned to the handle region.

(17) The crimping device 1 shown consists of an electrohydraulically actuatable crimping device 1 with an accumulator 4. The accumulator 4 is arranged opposite to a working end 5 of the crimping device. The crimping device 1 shown in FIG. 1 has an altogether elongate shape similar to a rod.

(18) It could alternatively also consist of a cable-bound crimping head. The control device could also be arranged distal referred to the crimping head.

(19) According to FIG. 1, as well as FIGS. 2 and 3, the crimping device 1 also features a crimping part 6 that is realized in the form of a crimping die in the exemplary embodiment shown.

(20) The crimping device 1 furthermore features a counterstop element 7, against which a workpiece to be crimped can be placed as illustrated, e.g., in FIG. 3.

(21) The counterstop element 7 in the exemplary embodiment shown forms a section of a first pivoting part 9 that can be interlocked with a second pivoting part 10, wherein both pivoting parts are respectively arranged on a device head 13 by means of pivot joints 11, 12 such that the closedbut laterally opendevice configuration illustrated in FIG. 3 is realized in the device head 13.

(22) The cross-sectional illustration according to FIG. 4 furthermore shows that the crimping device 1 features an electric motor 14 that is not illustrated in greater detail and preferably acts upon a pump 16 via a gear 15. A hydraulic medium, which preferably consists of hydraulic oil in this case, can be pumped into a cylinder chamber formed in a first hydraulic cylinder 17 by means of the pump 16. The hydraulic medium is accommodated in a hydraulic medium tank 19 that preferably surrounds the pump 16, as well as a backflow valve 18, in the exemplary embodiment shown.

(23) With respect to more detailed information on potential designs of the gear, the pump and the backflow valve, we refer to WO-A1 02/95264 (U.S. Pat. No. 7,086,979 B2), WO-A1 99/04165 (U.S. Pat. No. 6,202,663 B1) and WO-A1 99/19947 (U.S. Pat. No. 6,276,186 B1, U.S. Pat. No. 6,401,515 B2).

(24) The first hydraulic piston 20 is accommodated in the first hydraulic cylinder 17. The first hydraulic cylinder 17 has a longitudinal cylinder axis A. The first hydraulic piston 20 can be displaced axially to the longitudinal cylinder axis A.

(25) The first hydraulic piston 20 can also be returned into its initial position illustrated in FIG. 4 by means of a first pull-back spring 21 when the hydraulic pressure drops or the hydraulic medium is discharged.

(26) The first hydraulic piston 20 also has a first application face that results from the difference between the outside diameter a and the inside diameter b of the first hydraulic piston 20.

(27) The first hydraulic piston 20 is realized in the form of a partial piston and guides a second hydraulic piston 22 in its interior, namely centrally in its interior in the exemplary embodiment shown. The second hydraulic piston 22 has its own partial application face that is defined by the diameter b. Accordingly, the partial application faces preferably are respectively realized circularly and annularly in the exemplary embodiment. After a crimping operation has been completed, a second pull-back spring 23 makes it possible to return the second hydraulic piston 22, which is also referred to as second partial piston, into its initial position in the same fashion as already described in principle above with reference to the first hydraulic piston 20.

(28) The first hydraulic piston 20 is connected to a first crimping part 24. In the exemplary embodiment, the first crimping part 24 is realized such that it respectively extends out of a through-opening 25 in a cylinder bottom part 26 and also protrudes therefrom in the non-actuated state. The second partial piston 22 likewise continues in the form of a piston rod, the other end of which is even in the unused state free-standing in the circumferentially closed crimping space Ras preferred in the exemplary embodiment shownin the form of a second crimping part 27; see, e.g., FIG. 3.

(29) In the exemplary embodiment, the first crimping part 24 is axially covered in its entirety by the second crimping part 27. In an alternative embodiment indicated with broken lines 24 in FIG. 4 (but not illustrated for other figures), the first crimping part 24 may also protrude over the second crimping part 27 transverse to the cylinder axis A and, for example, fit together with the second crimping part 27 in a nested fashion as shown in the initial state according to FIG. 4.

(30) The two partial pistons 20 and 22 are guided inside of one another in a telescoping fashion. In this respect, it is proposed, in particular, that the second partial piston 22 with respect to its second piston rod protrudes over the first partial piston 20 with respect to its first piston rod in the initial position illustrated, e.g., in FIG. 4.

(31) The first partial piston 20 accordingly forms a second hydraulic cylinder for the second partial piston 22. The second partial piston 22 can be displaced relative to the first partial piston 20 by the distance c whereas the first partial piston 20 can be displaced relative to the first hydraulic cylinder 17, which is fixed with respect to the housing, by the distance d. Accordingly, the total maximum displacement of the second partial piston 22 corresponds to the sum of the distances c and d.

(32) The distance d is defined in that a stopping part 28 extends from the cylinder bottom part 26 into the first hydraulic cylinder 17, i.e. opposite to the direction, in which partial piston is displaced when a crimping operation is carried out. This stopping part may be realized in a sleeve-like fashion as in the preferred exemplary embodiment.

(33) Accordingly, the distance d also can be varied in a relatively simple fashion by inserting a stopping part 28 with a different length.

(34) Both partial pistons 20, 22 can jointly act upon the second crimping part 27 over a first partial traveling distance that corresponds to the distance d. When processing workpieces 8 that allow the crimping part 27 to travel a greater distance than the first partial traveling distanceuntil a maximum compressive force is reachedthe second crimping part 27 can then only be acted upon with the second partial piston 22.

(35) Accordingly, the second partial piston 22 also can be displaced farther forward than the first partial piston 20, wherein the relative displacement according to the distance c is in the preferred exemplary embodiment shown smaller than the distance d for the maximum displacement of the first partial piston 20 referred to the second hydraulic cylinder that guides the second partial piston 22 and is formed by the first partial piston 20.

(36) In the exemplary embodiment, the partial application faces defined by the dimensions a and b preferably are realized in such a way that the first partial application face assigned to the first partial piston 20 is larger than the second partial application face of the second partial piston 22.

(37) The restoring forces of the pull-back springs, which usually and in the preferred exemplary embodiment increase about linearly with the progression of the respective first or second partial traveling distance d or c, are preferably realized such that the restoring force of the second pull back spring 23 is greater than the restoring force of the first pull-back spring 21.

(38) Workpieces 8 of different sizes such as the cable lugs in the exemplary embodiment, which respectively have different sizes or different diameters in the crimping section, can be arranged in crimping device 1, particularly in the crimping space R in the exemplary embodiment shown. A cable lug 29 features a receptacle space 30, wherein an end of a cable 31that is stripped of its insulation in the exemplary embodimentis inserted into said receptacle space. The cable 31 is rigidly and electroconductively connected to the cable lug 29 by exerting a crimping action upon the receptacle space 30 of the cable lug 29 from outside.

(39) FIGS. 4-6 show a crimping operation carried out on a cable lug that is comparatively largereferred to the outside diameter of the receptacle space 30. In the exemplary embodiment shown, a hydraulic medium, in this case hydraulic oil, is pumped into the first hydraulic cylinder 17 and, if applicable, at the same time also into the second hydraulic cylinder by means of the electric motor 14, the connected gear 15 and the pump 16 when the crimping device 1 is actuated. As the displacement of the respective first and second partial pistons 20 and 22 progresses, the pressure in the hydraulic medium chamber or cylinder chamber continuously increases due to the counterpressure generated by the pull-back springs.

(40) A significant pressure increase occurs when the second crimping part 27 initially contacts the cable lug 29 as illustrated in FIG. 5. Since the first partial piston 20 25 has at this point not yet come in contact with the stopping part 28, both partial pistons 20, 22 continue to move in the direction of the cable lug 29 to be crimped.

(41) The displacement of the partial pistons 20, 22 continues until a maximum compressive force is reached; see FIG. 6. In the exemplary embodiment, the maximum compressive force is defined in that the automatic backflow valve is actuated; for details in this respect, see also aforementioned publication WO-A1 99/19947 (U.S. Pat. No. 6,276,186 B1, U.S. Pat. No. 6,401,515 B2).

(42) In deviation from this, it would also be possible, for example, to carry out a pressure measurement with respect to the pressure of the hydraulic medium in the cylinder chamber or a pressure measurement in the piston skirt of the first or second partial piston. In this case, a return movement of the hydraulic piston could be initiated as a function of the measured pressure, e.g., by opening a backflow valve, particularly in a motorized fashion.

(43) If the backflow valve 18 was automatically actuated, i.e. displaced into the open position, based solely on the pressure of the hydraulic medium reached as it is the case in the exemplary embodiment shown, the hydraulic medium flows back, the pressure in the cylinder chamber drops and the pistons are moved back into their initial position according to FIG. 4 by the pull-back springs.

(44) When processing a comparatively small cable lug 32 as it is the case in FIGS. 7-9, the first partial piston 20 already comes in contact with the stopping part 28 before the second crimping part 27 has reached its final crimping position (FIG. 9). As soon as the first partial piston 20 contacts the stopping part 28 during the course of such a crimping operation, the compressive force is only defined by the partial application face of the second hydraulic piston 22. In any case, the second crimping part 27 furthermore is telescopically displaced forward relative to the first crimping part 24 once the first partial piston 20 contacts the stopping part 28. However, such a telescoping movement also could already take place previously during the course of a crimping operation. This obviously also depends on the force of the pull-back springs 21, 23.

(45) When crimping a large workpiece, in this case a large cable lug of the type illustrated in FIGS. 4-6, the crimping part is in accordance with the method displaced over a shorter traveling distance before it reaches the final crimping position than when crimping a small workpiece 8 of the type illustrated in FIGS. 7-9. A compressive force, which can be exerted by the respective crimping part 24 or 27, is accordingly controlled as a function of the position of the respective crimping part 24 or 27 along the traveling distance, particularly the position of the stopping part 28 in the exemplary embodiment shown, such that a maximum compressive force is only exerted by the crimping part 24 and/or 27 in a final crimping position within a first partial traveling distance. In the exemplary embodiment, the first partial traveling distance is defined by the traveling distance of the first hydraulic piston 20 from an initial position, for example, according to FIG. 7 to the point, at which it reaches the stop 28 as shown in FIG. 9. If the final crimping position lies within a second partial traveling distance that follows the first partial traveling distance, however, only a partial compressive force that is lower than the maximum compressive force is exerted, wherein this partial compressive force is in the exemplary embodiment defined by the partial application face of the second hydraulic piston 22 that corresponds to the dimension and is the only effective partial application face remaining at this point. At the same hydraulic pressure, the smaller application face also generates a lower force.

(46) FIG. 10 shows a hydraulic device, particularly a hydraulic crimping device of the above-described type, with a workpiece 8 clamped therein.

(47) The second crimping part 27, which also may merely act as a clamping part in this case, is telescopically displaced forward relative to the first crimping part or clamping part 24.

(48) The aforementioned crimping or clamping parts 24, 27 are connected to the above-described partial pistons 20, 22. Both partial pistons 20, 22 are displaced in the direction of extension by a certain distance in the common hydraulic cylinder 27, particularly such that the second partial piston 22 acting upon the second clamping part 27 leads the first partial piston 20 acting upon the first clamping part 24.

(49) The exemplary embodiment shows that in fact only the second clamping part 27 acts upon the workpiece 8. However, it would also be conceivable that the workpiece 8 is simultaneously clamped by both clamping parts 24, 27.

(50) The displacement of the aforementioned partial pistons or clamping pieces has been carried out to such an extent that at least the second clamping part 27 is in clamping contact with the workpiece 8 as shown in FIG. 10. In this state, the displacement of the partial pistons can be stopped, for example, by releasing a control button or, if applicable, automatically when a certain crimping pressure is reached. Subsequent crimping of the workpiece can then be carried out, for example, in response to an additional actuation. Alternatively, the clamped workpiece may also be released again in response to a special actuation, e.g. of a return button.

(51) FIGS. 11-13 show a compression sleeve 33 prior to a crimping operation, wherein FIG. 11 shows the compression sleeve in its initial state. The compression sleeve 33 is realized in the form of a tubular part with constant diameter.

(52) Cables 31 and 34 with larger and smaller diameters are inserted into the compression sleeve 33 from two opposite sides as shown. A significant radial clearance obviously exists between the cable 34 and the inner surface of the compression sleeve 33. Cables of this type may consist of copper or aluminum cables. It is furthermore preferred that each cable is composed of a plurality of strands.

(53) The different diameters may be based on various conventional cable cross sections. For example, the pairing (large/small) may respectively have proportions of 35 mm.sup.2 to 16 mm.sup.2, 95 mm.sup.2 to 16 mm.sup.2, 185 mm.sup.2 to 70 mm.sup.2 or 120 mm.sup.2 to 95 mm.sup.2, but other variations such as, for example, 70 mm.sup.2 to 16 mm.sup.2, 120 mm.sup.2 to 95 mm.sup.2, etc., would also be conceivable.

(54) It is essential that two die impressions 35, 36 are produced adjacent to one another over a length L of the compression sleeve 33, wherein said die impressions are approximately identical as shown in FIG. 13. This is caused by different compressive forces acting upon the cable 31 of larger cross section on the one hand and the cable 34 of smaller cross section on the other hand during the crimping operation.

(55) According to FIG. 12, a significant deformation of the compression sleeve respectively takes place in the region of the die impressions 35, 36, but the compression sleeve is not destroyed.

(56) Due to the preferred utilization of a crimping device of the above-described type, the lower or higher compressive force is also automatically adjusted as a function of the crimped conductor with larger or smaller cross section.

(57) The preceding explanations serve for elucidating all inventions that are included in this application and respectively enhance the prior art due to the following combinations of characteristics, namely:

(58) A hydraulically actuatable crimping device, which is characterized in that the hydraulic piston 20, 22 consists of a first and a second partial piston 20, 22 with a first and a second partial application face, in that the partial application faces can be acted upon with hydraulic medium that has the same hydraulic pressure, and in that both partial pistons 20, 22 are respectively connected to a first and a second crimping part.

(59) A hydraulic crimping device, which is characterized in that the partial pistons 20, 22 are guided inside of one another in a telescoping fashion.

(60) A hydraulic crimping device, which is characterized in that the first partial piston 20 forms a second hydraulic cylinder for the second partial piston 22.

(61) A hydraulic crimping device, which is characterized in that the second crimping part 27 can be acted upon with both partial pistons 20, 22 over part of the traveling distance, wherein the second partial piston 22 preferably can be displaced farther forward than the first partial piston 20 referred to the first hydraulic cylinder 17.

(62) A hydraulic crimping device, which is characterized in that the size of the partial application faces differs, wherein the first partial application face is preferably smaller than the second partial application face.

(63) A hydraulic crimping device, which is characterized in that both partial pistons 20, 22 are respectively acted upon with a first 21 and a second pull-back spring 23.

(64) A hydraulic crimping device, which is characterized in that the crimping part 24, 27 consists of a crimping die.

(65) A method for carrying out a crimping operation, which is characterized in that the compressive force, which can be exerted by the crimping part 24, 27, is predefined as a function of a position of the crimping part 24, 27 along the traveling distance, namely in such a way that a maximum compressive force is only exerted by the crimping part 24, in a final crimping position within a first partial traveling distance and a partial compressive force, which is lower than the maximum compressive force, is exerted in a final crimping position within a second partial traveling distance that follows the first partial traveling distance.

(66) A method, which is characterized in that the completion of a crimping action is defined by reaching a predetermined pressure of the hydraulic medium acting upon the hydraulic piston 20, 22, wherein the same maximum pressure is preferably exerted upon an effective application face of a piston acting upon the crimping part 24, 27 irrespective of whether a final crimping position is reached in the first or the second partial traveling distance.

(67) A method, which is characterized in that the compressive force is controlled by varying the effective application face of the piston.

(68) A method for producing an electroconductive compression joint, which is characterized in that the compression sleeve 33, which has a constant inside diameter over its length, is in two opposite regions referred to a longitudinal direction of the compression sleeve crimped to the cables with different diameters by twice acting upon the compression sleeve 33 from outside with the same die, but with a different compressive force, namely at locations that lie adjacent to one another over the length of the compression sleeve and are respectively assigned to an end region of the cable with larger diameter and an end region of the cable with smaller diameter.

(69) An electroconductively crimped compression sleeve, which is characterized in that the cables have different diameters, in that the die impressions (35, 36) are identical, and in that the die impressions (35, 36) are produced in the compression sleeve with different depths, wherein a die impression assigned to the cable with smaller diameter is produced in the compression sleeve deeper than a die impression assigned to the cable with larger diameter.

(70) A method for clamping a workpiece, which is characterized in that a first and a second clamping part are provided, and in that a first and a second partial piston are provided and can be displaced relative to one another in a telescoping fashion in a common hydraulic cylinder against the force of a respective pull-back spring, wherein the first partial piston in any case displaces the first clamping part in order to clamp the workpiece, wherein both partial pistons furthermore are displaced as far as a clamping position, which results in clamping of the workpiece, such that the second partial piston leads the first partial piston when the partial pistons are acted upon with hydraulic medium, and wherein the displacement of the partial pistons is stopped in the clamping position.

(71) A hydraulic device, which is characterized in that a first and a second clamping part are provided, and in that a first and a second partial piston are provided and can be displaced relative to one another in a telescoping fashion in a common hydraulic cylinder against the force of a respective pull-back spring, wherein the first clamping part can in any case be displaced by the first partial piston in order to clamp the workpiece, wherein both partial pistons furthermore can be displaced as far as a clamping position, which results in clamping of the workpiece, such that the second partial piston leads the first partial piston when the partial pistons are acted upon with hydraulic medium, and wherein the displacement of the partial pistons can be stopped in the clamping position.

REFERENCE LIST

(72) 1 Crimping device 2 Handle region 3 Control switch 4 Accumulator 5 Working end 6 Crimping part 7 Counterstop element 8 Workpiece 9 First pivoting part 10 Second pivoting part 11 Pivot joint 12 Pivot joint 13 Device head 14 Electric motor 15 Gear 16 Pump 17 Hydraulic cylinder 18 Backflow valve 19 Hydraulic medium tank/chamber 20 First hydraulic piston 21 First pull-back spring 22 Second hydraulic piston 23 Second pull-back spring 24 First crimping part 25 Through-opening 26 Cylinder bottom part 27 Second crimping part 28 Stopping part 29 Cable lug 30 Receptacle space 31 Cable 32 Cable lug (small) 33 Compression sleeve 34 Cable 35 Die impression 36 Die impression A Longitudinal cylinder axis R Crimping space a Diameter b Diameter c Distance d Distance