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BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a tool for removing a chisel, in particular from a chisel holder, having a base element which receives an actuating member, wherein the actuating member has an expeller mandrel, and the actuating member is adjustable. 
     2. Discussion of Related Art 
     Similar tools are employed, for example, in connection with road milling machinery, recyclers, surface miners, and the like. They are used for removing chisels, in particular shank chisels, such as round shank chisels. In this case, the chisels are clampingly held in chisel receivers. Customarily, the chisel receivers are designed as through-bores. The chisel holders themselves are fastened to the surface of a milling roller tube, in particular welded to it, or are interchangeably fixed in base supports, which also are welded to the surface of a milling roller tube. Tools are known for making the removal of the chisels easier, such as are described in German Patent Reference DE 296 23 508 U1. 
     This tool has two lever arms, which are connected with each other by a joint. Here, one of the arms constitutes the expeller mandrel, and the other lever constitutes a handle element. The expeller mandrel can be inserted with its free end into the chisel receiver so that its end contacts the chisel shank of the chisel to be expelled. 
     The tool can be placed with the second lever against a support shoulder on the milling roller tube. Then, the chisel can be pushed out of the chisel receiver by a lever displacement. Finally, the expeller mandrel is threaded out of the chisel receiver. In the restricted assembly space, the manipulation of the double lever is difficult and is time-consuming. Further, the tool requires a support shoulder on the milling roller, which is not always available. 
     Removal tools are also known, which can be placed with draw-off claws against the chisel head of the chisel. In this case, a circumferential groove is required in the chisel head, into which the draw-off claws enter. It is not possible to perform a removal of the chisels, if the chisel heads are worn to such a large extent that the groove is no longer sufficiently available. Also, chisels with broken-off chisel heads cannot be removed. Such tools are known from German Patent References DE 43 23 699 C2, DE 32 23 761 A1, and DE 84 03 441 U1 and U.S. Pat. No. 6,526,641 B1. 
     A further tool is described in German Patent Reference DE 30 26 930 A 1. This tool has a support arm, which can be fixed in place against the chisel holder. A pivot lever, which has a handle, is coupled with the support arm. The chisel holder has a linearly displaceable plunger. For removing the chisel, a pivot arm facing away from the handle is placed against the plunger. As a result of displacing the handle, the plunger can be displaced and the chisel can be pushed out of the chisel receiver by it. The plunger, which is structurally connected with the chisel holder, constitutes an additional part and assembly cost. Further, it requires an increase in the structural space in the chisel holder, which is not always acceptable in connection with modern precision milling machines. 
     Also, this type of construction requires the fixation of the chisel in a blind hole-like chisel receiver which can become soiled during operation, which leads to a loss of the system. 
     SUMMARY OF THE INVENTION 
     It is one object of this invention to provide a tool of the type mentioned above but in which chisels can be simply and rapidly exchanged. 
     This object is attained in that the actuating member is coupled indirectly or directly to a fluid-charged cylinder-piston system, or to an electric motor-driven unit. For example, the cylinder can be a fluid cylinder, in particular a hydraulic cylinder, which can be charged via an oil circuit. With this it is possible to build up a large pressure on the piston and to transmit correspondingly large forces to the actuating member. Thus it is possible to dependably remove chisels without a large force expenditure. The electric motor driven unit can, for example, be a spindle-nut unit, which can be driven by an electric motor. 
     In accordance with one embodiment of this invention, the actuating member is seated on the base element, pivotable around a stationary pivot bearing. The base element can be associated with the chisel holder, and a reproducible expelling process can be realized via the stationary pivot bearing. 
     If, with the displacement movement of the actuating member, the expeller mandrel moves on a curved course, it is possible to realize a varying progression of the moment. For example, with an appropriate layout of the tool it is possible to generate a high moment at the start of the displacement movement, which is then continuously reduced. Thus the condition, at the start of the displacement movement when it is necessary to initially overcome the frictional adherence between the chisel and the chisel receiver, is simply met. 
     In a preferred manner, the base element has a support section for direct support on the chisel holder, or indirectly on the chisel holder, for example on a wear disk. With the stationary assignment of the tool to the chisel holder it is possible to do without additional support elements, for example an expelling shoulder on the milling roller tube. Thus it is possible to realize a more compact arrangement of the individual chisel holders on the milling roller tube and no additional cost outlay is required, such as with the prior art. 
     Preferably, those locations on the chisel holder are used for the support, which are not subject to excessive wear, so that the tool can always be placed in a reproducible manner. The wear disk in particular, which is customarily arranged between the chisel head and a support surface of the chisel holder, provides an ideal support location. 
     For example, the support section can be arranged on a fork-shaped expelling element. The tool can be placed against the chisel holder with the fork-shaped expelling element so that the support section comes to lie on the side of the chisel head of the chisel. There, the support section can engage the wear disk. 
     In accordance with one embodiment of this invention, distanced from the support section, the base element has an externally located contact face for placement against the chisel holder. It is possible with the support section and the contact face to provide a definite assignment of the tool and the chisel holder. Thus, the tool can always be associated in the same way with the chisel holder. 
     In one embodiment of this invention, the base element has a receptacle, in which the actuating member is received between two lateral walls which delimit the receptacle, and the lateral walls have seating receptacles in which the actuating member is pivotably seated. 
     This simple structural design makes possible the stable guidance of the actuating member between the two lateral walls. 
     In one embodiment of this invention, the displacement movement of the actuating member is limited by at least one stop arranged on the base element. Then the displacement movement of the actuating member can be limited. In this case, the actuating member can be controlled so that the jamming of the actuating member in its end position is not possible. 
     In case of an appropriate limitation, the actuating member is positioned by a stop in its initial position so that the easy placement against the chisel holder is possible. The limitation of the actuating movement of the actuating member in the removal position prevents the actuating member from becoming jammed in the chisel receiver. 
     In particular, the actuating member can be movable out of its initial position into the removal position, and the actuating member can be maintained in a spring-loaded manner in its initial position by a spring element. This step assures that, when the cylinder is switched to no pressure, the actuating member remains in its initial position, or respectively returns into it. For example, in case of the use of a double-acting cylinder, it is possible to do without the spring-loading. 
     In order to achieve a simple and dependable operation of the tool also in locations which are hard to access, the base element is coupled with a handle element indirectly or directly by a connecting member, and the handle element is pivoted with respect to the base element by a pivot bearing. 
     In one embodiment of this invention, the expeller mandrel is connected to a lever arm having a coupling for the pivotable connection of the piston rod, and the lever is pivotably seated at a distance from the coupling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This invention is explained in greater detail in view of exemplary embodiments represented in the drawings, wherein: 
         FIG. 1  shows a base support with a chisel holder, to which a tool is assigned, in a first operating position in a lateral view and in partial section; 
         FIG. 2  shows the representation in accordance with  FIG. 1 , in a second operating position; 
         FIG. 3  shows the representation in accordance with  FIG. 1 , in a third operating position; 
         FIG. 4  shows an adapter of the tool represented in  FIG. 1 , in a perspective representation; 
         FIG. 5  shows the base support and the chisel holder in accordance with FIG.  1  in a lateral view and partial section, in which a further embodiment of the tool is assigned to the chisel holder; 
         FIG. 6  shows the base support and the chisel holder in accordance with  FIG. 1  in a lateral view and in partial section, in which a third embodiment variation of the tool is assigned to the chisel holder; 
         FIG. 7  shows the base support and the chisel holder in accordance with  FIG. 1  in a lateral view and partial section, in which a fourth embodiment of the tool is assigned to the chisel holder; 
         FIG. 8  shows a milling roller tube with a chisel holder fastened on it in a lateral view and in partial section, in which a fifth embodiment variation of the tool is assigned to the chisel holder. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a tool  10  with a handle  12 . A battery is integrated into the handle  12 . The battery can be charged in an appropriate charging station via two electrical current contacts  11 . The battery is used for supplying electrical current to an electric motor. The electric motor is contained in a housing attachment, which is connected to the handle  12 . A cylinder  13  is contained in this housing attachment. The cylinder  13  can be embodied as a hydraulic cylinder, so that an appropriate hydraulic circuit system is integrated into the housing attachment. A piston is seated in the cylinder  13  and is displaceable between two end positions. A trigger  12 . 1  is installed on the handle  12 . The trigger  12 . 1  closes a contact of an electrical circuit and thus activates the electric motor in the housing attachment. The electric motor, together with the hydraulic system, causes the displacement of the piston in the cylinder  13 . Alternatively, it is possible to integrate lines into the handle  12 , which are conducted to fluid connectors on the handle  12 . The fluid connectors are designed as quick-release couplings. 
     They can be connected to counter-coupling elements of hoses. The hoses can extend, for example, from a hydraulic system of a road milling machine or a surface miner. The lines integrated into the handle  12  are conducted to the cylinder  13 . Also, a piston is housed, linearly displaceable, in the handle  12 . The displacement movement of the piston can be regulated by a valve, which is controllable by a trigger  12 . 1  on the handle  12 . The adapter  20  represented in  FIG. 4  can be connected to the cylinder  13 . This adapter  20  will be explained in greater detail by referring to  FIGS. 1 and 4 . It has a base element  20 . 1 . With two lateral walls  20 . 4 , the base element  20 . 1  delimits a receptacle  20 . 2 . An actuating member  60  in the form of a lever is pivotably seated in this receptacle  20 . 2 . The actuating member  60  has a lever arm  64 , to which an expeller mandrel  65  is connected in one piece. The expeller mandrel  65  is formed in the shape of a bow. The free end of the expeller mandrel  65  can be convexly crowned. On its end facing away from the expeller mandrel  65 , the lever arm  64  has a bore, which constitutes or forms a seating receptacle  63 . 
     The seating receptacle  63  is aligned with corresponding bores in the lateral walls  20 . 4 . A seating bolt  20 . 6  is pushed through the aligned bores and the seating receptacle  63 , and can be secured by locking rings, as shown in  FIG. 4 . The seating bolt  20 . 6  constitutes or forms a rotary shaft which, in accordance with  FIG. 1 , extends vertically with respect to the drawing plane. The lever arm  64  has a coupling  62  in the area between the seating receptacle  63  and the connecting point of the expeller mandrel  65  on the lever arm  64 . A piston rod  14  can be connected by its seating receptacle  15  with the coupling  62 . On its end facing away from the seating receptacle  15 , the piston rod  14  has a collar  16 , as shown in  FIG. 4 . A connecting element  20 . 10  is formed in one piece on the base element  20 . 1 .  FIG. 1  shows that the connecting element  20 . 10  has a cup-shaped receptacle, which is in a spatial connection with the receptacle  20 . 2  via a through-bore. A spring element  20 . 11  is inserted into the cup-shaped receptacle. The spring element  20 . 11  can be designed as a helical spring. The piston rod  14  is conducted through the helical spring, so that the free end of the piston rod  14  comes into contact with the actuating member  60 . 
     In the process, the piston rod  14  comes to lie with its seating receptacle  15  against the coupling  62 . In the area of or near the coupling  62 , the lever arm  64  has two bores aligned with each other, which can be aligned with the seating receptacle  15  in the piston rod. 
     Thus, the collar  16  of the piston rod  14  is placed against the spring end protruding from the cup-shaped receptacle. It is then possible to compress the spring element  20 . 11  by pressure on the collar  16  until the seating receptacle  15  is aligned with the bores in the coupling  62 . A hinged bolt can be pushed through the aligned bores and the seating receptacle  15 . As  FIG. 4  shows, circular passages  20 . 5  are provided in the lateral walls  20 . 4 . 
     With its bores, the lever arm  64  can be aligned with the bores in the coupling  62 . It is then possible to expel the hinged bolt through the passages  20 . 5  into the bores of the lever arm  64  and through the seating receptacle  15 . Simple coupling, or respectively uncoupling, of the piston rod  14  can thus be performed. In the coupled state, the piston rod  14  is maintained under spring pre-tension in the position shown in  FIG. 1 . Thus, the actuating member  60  is also fixed in this position. 
     The adapter  20  can be connected with the housing attachment by the connecting element  20 . 10 . In this case a rotary seating is formed between the connecting element  20 . 10  and the housing attachment, so that the housing attachment can be rotated with respect to the base element  20 . 1 . In the mounted state, the piston rod  14  rests with its collar  16  against the piston, which is guided in the cylinder  13 . Here, the piston is arranged in the cylinder  13  in its end position, which defines the expelling position. 
     As shown in  FIG. 1 , stops  20 . 8  and  20 . 9  are provided in the area of or near the receptacle  20 . 1  of the base element  20 . 1 . 
     The stops  20 . 8  and  20 . 9  are used for limiting the displacement movement of the actuating member  60 . Thus, the actuating member  60  has corresponding end faces, which can be brought into contact with the stops  20 . 8  and  20 . 9 . In  FIG. 1 , the actuating member  60  rests against the stop  20 . 8 . In  FIG. 3 , the actuating member  60  rests against the stop  20 . 9 . 
     As shown in  FIG. 4 , an expelling element  20 . 13  is formed in one piece with the base element  20 . 1 . The expelling element  20 . 13  is in a fork shape and has a support section  20 . 14 . 
     The tool  10  is used for removing a chisel  50 , which is received in a chisel holder  40 . The chisel holder  40  is exchangeably maintained in a base support  30 . 
     Thus, the base support  30  has a plug-in receptacle, which receives a plug-in shoulder of the chisel holder  40 . The chisel holder  40  can be fixed in place on the base support  30  by an attachment screw  32 . The base support  30  has a concave support face  31  which can be placed on the surface of a milling roller tube and welded in place on it. The chisel holder  40  has a neck  41 , into which a chisel receiver  43  is cut in the form of a bore. The back of the chisel receptacle  43  is accessible through a cutout  42 . In the present case, the chisel  50  is embodied as a round shank chisel and has a chisel head, on which a chisel shaft  51  is formed in one piece. A clamping sleeve is drawn on the chisel shaft  51 . The clamping sleeve is maintained on the chisel shaft  51  so that it cannot be axially displaced, but is freely rotatable in the circumferential direction. As  FIG. 1  shows, the chisel  50  is inserted with its chisel shaft  51  into the chisel receptacle  43  of the chisel holder  40  so that it is clampingly maintained therein by the clamping sleeve. In the inserted state, the chisel  50  is supported through its chisel head on a wear-protection disk  54 , which is drawn on the chisel shaft  51 . The wear-protection disk  54  is arranged between the chisel head and the clamping sleeve. With its side facing away from the chisel head, the wear-protection disk  54  rests against a support face of the chisel holder. 
     When operationally used, the chisel  50  can rotate with its chisel head on the wear-protection disk  54 . In the process, the chisel shaft  51  also rotates in the clamping sleeve. In the customary manner, the chisel head of the chisel  50  has a chisel tip  52  of a hard alloy, for example. 
     Once the chisel reaches a worn-out state, it must be removed. Here, the tool  10  described in the drawing figures is used. The tool  10  is then placed on the chisel holder  40 , while the expelling element  20 . 13  rests with its support section  20 . 14  on the front of the wear-protection disk  54 . The expelling element  20 . 13  can also be indirectly or directly supported on a suitable, arbitrary location of the chisel holder  40 . 
     In the process, a positive connection in the mounting direction of the chisel should be produced between the expelling element  20 . 13  and the chisel holder  40 . Also, the base element  20 . 1  has a contact face  20 . 7 , by which the base element  20 . 1  is supported on the surface of the chisel holder  40 . It is possible to cause a defined coordination of the tool  10  and the chisel holder  40  by the contact face  20 . 7  and the support section  20 . 14 . While placing the tool  10  against the chisel holder  40 , the expeller mandrel  65  also moves through the cutout  42 . In the process, the free end of the expeller mandrel  65  is arranged opposite the free end of the chisel shaft  51 . The free end of the chisel shaft  51  forms a support face  53 . Once the tool  10  is brought into the position shown in  FIG. 1 , the trigger  12 . 1  on the handle  12  can be operated. 
     With the actuation of the trigger  12 . 1 , the electric motor in the housing attachment is activated and supplies hydraulic fluid to the cylinder  13 , so that the piston is displaced in the cylinder  13 . Because the piston rests indirectly or directly against the collar  16  of the piston rod, the piston rod is also displaced into the positions shown in  FIG. 2 . The spring element  20 . 11  is also compressed during this displacement movement. 
     With the displacement of the piston rod  14 , the actuating member  60  is pivoted around its seating receptacle  63 . During this, the actuating member  60  dips with its expeller mandrel  65  into the chisel receptacle  43  so that the free end of the expeller mandrel  65  comes into contact with the support face  53  on the chisel shaft  51 . With the displacement of the actuating member  60 , the chisel  50  is pushed out of the chisel receptacle  43 . During this, the support section  20 . 14  maintains the wear-protection disk  54  in its position. Accordingly, the clamping sleeve is pushed into the cylindrical bore of the wear-protection disk  54 . During this, the clamping sleeve is compressed radially inward, because of which the clamping effect is partially compensated. Thus a lesser expelling force is required. The actuating movement of the actuating member  60  is limited by the stop  20 . 9 . 
     In this final position, a switch also turns off the electrical current supply for the electric motor in the housing attachment. This operating position is shown in  FIG. 3 . Here, the chisel  50  is moved completely out of the chisel receptacle  43 . Because power for the electric motor is cut off, the hydraulic pressure is removed from the piston. 
     The spring element  20 . 11  can then reduce its pre-tension, so that the actuation member  60  is moved back in a counterclockwise direction into its initial position shown in  FIG. 1 . During this, the piston in the cylinder  13  is also moved back into its initial position. The tool  10  can be removed from the chisel holder  40 , so that the wear-protection disk  54  is released. The chisel  50  can be removed. 
     variations are shown in  FIGS. 5 to 8 . In the representations in accordance with  FIGS. 5 to 7 , the holder exchange system, including the base support  30 , the chisel holder  40  and the chisel  50 , corresponds to the arrangement in accordance with  FIGS. 1 to 4 .  FIG. 8  illustrates that the tools  10  in accordance with this invention are not solely restricted to employment with these basically known exchange systems. Rather, an individual case is also possible in which the chisel holder  40  is welded directly on a milling roller tube F, such as shown by the weld seam  44 . 
     Essentially, the tool embodiment in accordance with  FIG. 5  corresponds to the embodiment in accordance with  FIGS. 1 to 4 . Only the actuating member  60  is constructed differently. This actuating member  60  is designed as a plane gear in the form of a four-link system, which saves structural space. Two levers  61 ,  65 . 2  are hingedly connected via pivot bearings  65 . 1 ,  65 . 4  to an expeller mandrel  65 . In this case, the pivot axes are oriented perpendicularly with respect to the drawing plane. 
     Facing away from the expeller mandrel  65 , the lever  61  is connected to the piston rod  14  via a pivot bearing, such as the seating bolt  20 . 6 . This connecting area corresponds to the connecting area of the piston rod  14  to the actuating member  60  in accordance with  FIGS. 1 to 4 . Reference is made to the above explanations. 
     On an end facing away from the expeller mandrel  65 , the second lever is connected to the lateral walls  20 . 4  by a pivot bearing  65 . Again, the pivot axes are oriented perpendicularly with respect to the drawing plane.  FIG. 5  shows the initial position of the tool. When actuating the trigger  12 . 1 , the piston rod  14  is displaced linearly downward in the drawing plane. In the process, the levers  61  and  65 . 2 , which are connected via the expeller mandrel  65 , are synchronously pivoted in a clockwise direction. The expeller mandrel  65  simultaneously enters into the chisel receptacle  43  and pushes the chisel  50  on its support face  53  out of the chisel receptacle  43  while overcoming the clamping force of the clamping sleeve S. 
     After reaching the expelling position, the spring element  20 . 11  pushes the actuating member  60  back into the initial position shown in  FIG. 5 . 
       FIG. 6  shows a further tool embodiment, in which the adapter  20  again essentially corresponds to the adapters  20  in accordance with  FIGS. 1 to 5 . Thus, only the different characteristics are addressed, and reference is otherwise made to the above explanations. The connecting element  20 . 10  of the adapter  20  has a receptacle, into which a bent tube  66 . 2  is inserted and is held there. An element  66 . 7  of low flexural strength, in this case a link chain, such as is also used in principle in propulsion technology, is inserted into the tube  66 . 2 . With its one end, the link chain is pivotably fastened to the seating receptacle  15  of the piston rod  14 . At the other chain end, the last chain link constitutes or forms the expeller mandrel  65 .  FIG. 6  again shows the initial tool position. When actuating the trigger  12 . 1 , the piston rod  14  is displaced, such as downward. In the process, it enters into a cylindrical connecting area of the tube  66 . 2 . 
     The link chain is displaced in the tube  66 . 2 , and in the process the tube  66 . 2  prevents the link chain from kinking. The expeller mandrel  65  is supported on the support face  53  of the chisel  50  and pushes it out of the chisel receptacle  43 . 
     Once the link chain reaches the area of the chisel receptacle  43 , the latter prevents it from kinking. After reaching the end position, the spring element  20 . 11  places the actuating member  60  back into its initial position shown in  FIG. 6 . 
     In the tool in accordance with  FIG. 7 , the tube  66 . 2  is preferably filled with a fluid  66 . 3  in place of the link chain. A piston  66 . 1  is connected to the piston rod  14  by a crosshead link. With its exterior contours, the piston  66 . 1  provides a seal on the interior wall of the cylindrical area of the tube  66 . 2  with the aid of a seal ring. A second piston  66 . 1  is sealingly seated at the other tube end, which is also cylindrically embodied. The piston  66 . 1  can be linearly displaced and supports the expeller mandrel  65 . The tube  66 . 2  can enter into the chisel receptacle  43  through the cutout  42 , so that the expeller mandrel  65  lies opposite the support face  53  of the chisel  65 . During displacement of the piston rod  14 , the piston  66 . 1  is pushed into the tube  66 . 6 . The fluid  66 . 3  transmits this actuating movement to the second piston  66 . 6 . In the process, the expeller mandrel  65  pushes the chisel  50  out of the chisel receptacle  43 . During relief of the piston rod  14 , the spring element  20 . 11  pushes the actuating member  60  into the initial position. The piston  66 . 1  is thus pulled upward. With the creation of a vacuum, the second piston  66 . 6  is also aspirated back into its initial position by the fluid  66 . 3 . 
     In  FIG. 8 , a tool  10  is shown, in which an electric motor  66 . 8  is integrated into the handle  12 . The output shaft  66 . 9  of the electric motor  66 . 8  has a spindle  66 . 11 . Facing away from the electric motor  66 . 8 , the output shaft  66 . 9  is rotatably fixed in place by a ball bearing  66 . 10 . Also, the actuating member  60  is received in the adapter  20  between the two lateral walls  20 . 4  and in the present case has the shape of a disk. The edge of the actuating member  60  has a tooth arrangement  66 . 12 , which meshes with the spindle  66 . 11 . 
     The actuating member  60  is held in the adapter  20 , and the seating receptacle  63  constitutes or forms the pivot axis. The actuating member  60  supports the expeller mandrel  65 , which is formed as one part of, and eccentrically with respect to, the seating receptacle  63 . 
     Again, the tool  10  can be inserted with the expeller mandrel  65  through the cutout  42  into the chisel receptacle  43 , so that the expeller mandrel  65  lies opposite the support face  53  of the chisel  50 . When actuating the trigger  12 . 1  on the handle  12 , the electric motor  66 . 8  is activated. Thus, the output shaft  66 . 9  is set into rotary motion. Via the tooth arrangement  66 . 12 , the spindle  66 . 11  turns the actuating member  60  in a clockwise direction. A sufficiently large lever arm is formed by the spacing of the tooth arrangement  66 . 12  with respect to the pivot bearing  63 . A large force reduction is made possible by employing the spindle gear. Upon a rotation of the actuating member  60 , the expeller mandrel  65  pushes the chisel  50  out of the chisel receptacle  43 . After reaching the push-out position, the electric motor  66 . 8  changes directions and changes the direction of rotation until the actuating member  60  again reaches an end position shown in  FIG. 8 . The electric motor  66 . 8  is then switched off in this position. 
     It is understood that the described tool  10  can also be employed in connection with the most diverse, suitable chisel holders  40  and holder exchange systems. 
     German Patent Reference 10 2008 025 071.6-15, filed 26 May 2008, the priority document corresponding to this invention, to which a foreign priority benefit is claimed under Title 35, United States Code, Section 119, and its entire teachings are incorporated, by reference, into this specification.

Summary:
A tool for removing a chisel, in particular from a chisel holder, having a base element which receives an actuating member, wherein the actuating member has an expeller mandrel. The actuating member is adjustable along a displacement direction. In order to be able to perform the removal simply and rapidly, the actuating member of this invention is indirectly or directly coupled to a piston of a fluid-charged cylinder, or to an electric motor unit.