Abstract:
The linear path slide ( 100 ) with a slide ( 10 ) which is arranged with a sliding guide ( 12 ) slidingly movable and resistant to torsion in a housing ( 11 ) and with a hydraulic driving gear which causes the translation movement of the slide ( 10 ) and which has a piston ( 24 ) arranged slidingly movable in a cylinder by constituting a hydraulic working space ( 13 ), is configured in such a way that the cylinder and the working space ( 13 ) are placed in the slide ( 10 ), the piston ( 24 ) being fixed with respect to the housing ( 11 ).

Description:
[0001]    The present invention relates to a linear path slide with a slide which is arranged with a sliding guide slidingly movable in a housing and with a hydraulic driving gear which causes the movement of the slide and which has a piston arranged slidingly movable in a cylinder by constituting a hydraulic working space.  
         BACKGROUND OF THE INVENTION  
         [0002]    Linear path slides of the above mentioned type are used as actuators in different devices for the processing and machining of metallic materials and plastic or plastic composite materials. The functions of these structural components typically include the pressing, forming, stamping, bending, beading, punching, jointing, jointing pressing as well as the carrying out of feeding functions with special requirements. Particular requirements are made to the properties of linear path slides among which especially a high energy density, a very high guiding exactitude as well as a very high stiffness against transverse loads and torsion are to be found. Furthermore, they should be constructed as compact as possible and allow, as standardized basic structural components, a flexible universal range of application. Moreover, properties such as maintenance-freedom during the whole lifetime, a robust construction for the use in polluted environment, the possibility of any fitting position, absolute tightness (for example by overhead mounting) and not least a low-cost production are desirable.  
           [0003]    Different configurations of linear path slides are known. Because of the required high energy density, they are preferably hydraulic devices. However, basically the design as a pneumatically driven device is also possible.  
           [0004]    Especially combinations of customary linear cylinders are known as compact built-in modules which are formed with stiff linear guiding units by “saddle-mounting” or by constituting a constructional longitudinal combination.  
           [0005]    From DE-GM 71 04 168, we know a hydraulically or pneumatically acting slide for translating or swivelling blades, flaps or containers for which the hydraulic working spaces are configured in the stemple of the device. In order to protect the piston rod of the device used in severe conditions against dirt, faling rocks and the like, it is surrounded by a protecting sheath. The slide is guided only by the piston rod and thus does not show any torsion stiffness. Therefore, it is appropriate only for receiving linear forces.  
           [0006]    Moreover, hydraulic block cylinders are known, the housings of which have additional bore holes for guiding rods which are placed parallel to the actual hydraulic cylinder. The piston rod head and one to usually four guiding rods at the most are screwed to each other in a top plate resistant to bending. This arrangement guarantees flexural strength and torsional strength.  
           [0007]    Furthermore, from DE 295 17 615 U1, we know a linear path slide with a slide, which is placed slidingly movable in a housing with guide rollers and resistant to torsion, and with a hydraulic driving gear which causes the displacing of the slide and which shows a piston placed slidingly movable in a cylinder by constituting a hydraulic working space. Due to the only point support of the slide valve on the rollers, the torsional strength and the capacity of absorbing transverse loads are however limited.  
           [0008]    Moreover, the linear path slide shows a relatively big axial overall length.  
           [0009]    Another configuration of a linear path slide (Manufacturer Heidel GmbH und Co, KG, Viersen, Germany) is known for the particularly high requirements in the field of cutting tools. This embodiment is characterized by a prismatical slide with an usually right-angled cross-section. The slide core is guided with a cast housing absolutely free from backlash and maintenance-free (for lifetime) due to a special heavy-load slideway technique. The slide shows a pocket into which a special hydraulic cylinder is inserted laterally to the movement axis. This hydraulic cylinder shows a piston with two continuous piston rods or with a piston rod and a driving slot which act onto the front sides of the pocket in the slide and thus transfer the forces of pressure onto the slide for a forward and a back motion. The hydraulic special cylinder is provided on one longitudinal side with a mounting flange by means of which it is screwed on the slide housing. For this purpose, the slide housing has an opening on its upper longitudinal side. The hydraulic oil connections are also on this mounting flange. There is a lateral connection as well as a connection orientated upwards with a corresponding guiding of the pipes in order to be adapted to different confined mounting conditions. The described linear path slide is characterized by its heavy-load capacity and the precise slideway of the prismatical slide. However, its useability is limited in some cases by its size and weight. Moreover, a repair of the linear path slide is relatively complicated.  
         SUMMARY OF THE INVENTION  
         [0010]    The aim of the invention is to obtain, for a linear path slide of the above mentioned type, a compacter construction with a reduced volume and a reduced weight. Simultaneously, the linear path slide should be easier to repair and should be flexibler in its useability. Not least the manufacturing costs should also be reduced.  
           [0011]    This aim is achieved by the characteristics indicated in claim 1.  
           [0012]    Accordingly, the linear path slide contains in a known way a slide which is arranged slidingly movable in a housing with a sliding guide as well as a hydraulic driving gear which causes the displacing of the slide and which has a piston arranged slidingly movable in a cylinder by constituting a hydraulic working space. Accordingly, this linear path slide is characterized in that the cylinder and the working space are configured in the slide and the piston is fixed with respect to the housing.  
           [0013]    Here, by “cylinder”, we do not necessarily understand a cylinder in the mathematical sense, i.e. with a circular cross-section, but any working space limited by parallel walls in which a piston, the cross-section of which corresponds to the cross-section of the working space, can move parallel to the walls. Besides a mathematical cylindrical shape, the “cylinder” can also show in particular a cross-section in form of a regular polygon in the sense of the claims.  
           [0014]    In the linear path slide according to the invention, the functions of the slide and of the hydraulic driving gear are combined in a structural component. This is possible since the hydraulic driving gear is integrated into the slide itself. Many advantages result from this measure. So, the giving up of two separated structural components (slide, hydraulic driving gear) allows a compacter thinner construction by saving construction volume. Components are additionally saved (for example housing with cylinder bore hole and mounting flange) and thus a high saving of costs and weight is achieved. The falling away of junctures in which for example the mechanical pressure force introduction takes place from the hydraulic driving gear to the slide, causes a further reduction of the production costs and avoids potential sources of errors.  
           [0015]    Furthermore, for the linear path slide according to the invention, the arrangement of the slide and of the hydraulic driving gear can ensue with a high symmetry, the cylinder and the piston being placed on the center axle/axle of movement of the slide. Thus, there results a central and symmetrical force introduction which avoids the occuring of tilting moments. This causes a lower parasitic stress and increases the reliability and the longevity of the structural component. For linear path slides with a traditional construction, a corresponding symmetrical configuration would have resulted in considerably bigger structural shapes with an inacceptable specific power capacity.  
           [0016]    Advantageous configurations of the invention are characterized in the subclaims.  
           [0017]    The slide is constructed according to claim 2 preferably as a prismatic slide. Thus, a high precision and a high stiffness are obtained in an experienced way.  
           [0018]    Furthermore, it is preferred according to claim 3 that the sliding guide, which is placed between the slide and the housing, is produced by a casting process. Such a casting process results on the one hand in a very high quality sliding guide and is simultaneously very advantageous as to the costs.  
           [0019]    In an advantageous further development of the invention mentioned in claim 4, the piston separates the cylinder into two separate working spaces, a volume increasing of the working spaces resulting in an opposite movement of the slide. In this way, it is possible through the inflow of hydraulic media and a pressure feeding into the corresponding working space to cause an active forward movement of the slide as well as an active back movement thereof. Since the piston divides the existing cylinder space into two parts, an optimal using of this space is simultaneously obtained.  
           [0020]    For a possible realization of this alternative of the invention, the piston is placed at the end of a piston rod which has a smaller diameter than the piston and which is guided outwards on one side of the cylinder (i.e. of the slide). Here, the duct of the piston rod is tightly sealed all around so that no hydraulic media can flow out. In this arrangement, the piston separates the cylinder space into two working spaces which can be designated as lying on this side and on the other side of the piston rod. An introduction of pressure into the respective working spaces affects different sides of the piston and thus results in corresponding opposite forces onto the slide.  
           [0021]    For fulfilling their function, the hydraulic working spaces must be provided with a feeding pipe for hydraulic media (for example oil). According to claim 5, this feeding pipe is preferably placed in the piston and in the piston rod connected with the piston. Such an arrangement utilizes the fact that, on the one hand, the piston of the linear path slide according to the invention is fixed and, on the other hand, that it constitutes a part of the delimiting walls of the working space. Thus, the feeding pipe of the hydraulic media can be guided without problem from an outer connection through the piston rod and the piston to the place of use (and back). This is naturally also the case when, as in an above described embodiment of the invention, two working spaces are configured within the slide.  
           [0022]    In the last mentioned case in which two different working spaces are fed with feeding pipes through the piston, these feeding pipes are preferably placed, according to claim 6, parallel or concentrically in the piston. Since the parallel arrangement allows a simpler fabrication due to deep bore holes with less structural components, the concentrical arrangement is especially chosen when the linear path slide should be configured very compact.  
           [0023]    In a further development of the invention according to claim 7, the slide has a rear and/or a front limit stop sensor. This sensor allows to ascertain and to supervise if the slide is at one of the limit stops. This information is generally important for the higher processing step so that the precise detection of this state can advantageously be used for controlling the whole process.  
           [0024]    According to claim 8, the piston is detachably connected with the housing, whereby especially a screw-type and/or bayonet-type fixing is possible as a connection. A maintenance and repair of the linear path slide is possible by loosening the piston from the housing. Here, only one component has to be loosened in order to simultaneously obtain the access to the hydraulic space and to the slide. The maintenance of the linear path slide is thus considerably simplified which becomes apparent in the lower operating costs and in a longer lifetime.  
           [0025]    In a further development of the invention according to claim 9, it is provided that the hydraulic cylinder is no longer directly formed by the inner wall of the stemple but by a separate cylinder case. This case is placed in a corresponding opening in the stemple. Such an arrangement has the advantage that the hydraulic unit is entirely placed in the cylinder bush and can also thus be entirely disassembled from the rear side of the linear slide without the slide itself having to be removed. Tools mounted on the slide such as, for example, precisely aligned cutters or the like have not to be removed. Thus, the risk of a deterioration of the inner wall or of the sliding guide by the tools is excluded. Moreover, the hydraulic oil is encapsulated by the cylinder bush and thus cannot soil the mounting place. Finally, the widening of the stemple is also avoided, since the hydraulic pressure does not act directly onto the stemple but onto the cylinder bush. This is extremely advantageous considering the anyway narrow tolerances of the slide gap. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    Embodiments of the invention will be described below with reference to the attached drawings.  
         [0027]    [0027]FIG. 1 shows a top view of the linear path slide during a working stroke.  
         [0028]    [0028]FIG. 2 shows a detail of the top view of the linear path slide.  
         [0029]    [0029]FIG. 3 shows a back view of a linear path slide with a bottom flange.  
         [0030]    [0030]FIG. 4 shows a back view of a linear path slide with through fastening screws.  
         [0031]    [0031]FIG. 5 shows a back view of a linear path slide with a plug/turn cylinder rod locking.  
         [0032]    [0032]FIG. 6 shows an alternative configuration of a linear slide with a cylinder bush which is placed in a blind hole of the stemple. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]    In FIG. 1, a top view of a linear path slide  100  according to the invention is represented, the housing  11 , the slide  10 , the piston and the piston rod being represented partially opened in the upper half of the picture in order to make the inner structure recognizable. The linear path slide  100  has a compact and substantially cuboid structural shape. It consists of a housing  11  which has at, its lower end, a bottom flange with bore holes  17  for fastening screws and dowel pins for fixing the linear path slide to a machine (see also FIG. 3). Furthermore, a groove  18  is placed on the lower side of the housing  11  for receiving a feather key on the mounting surface.  
         [0034]    The slide  10  is placed slidingly movable in the housing  11  in direction of the longitudinal axis of the housing (horizontal level in FIG. 1). The slide is preferably constructed with a square core. The slide  10  has a mounting surface  16  accessible from outside in which one or several threaded holes  15  are sunk-in for the mounting screws. In this way, different elements can be connected with the slide  10  depending on the purpose of application. The slide  10  is placed slidingly movable in direction of its longitudinal axis and can be moved out of the housing  11  by the length of its working stroke. Usual stroke paths lie between 30 and 100 mm, for special designs also up to 500 mm. The forces, which the slide  10  has to exert in axial direction (longitudinal forces) are in the range of 10 kN (1 to) to 100 kN (10 to), in particular cases also up to 250 kN (25 to). Due to an eccentric stress of the slide during the working process, the transverse loads onto the slide even can be a multiple of the nominal force of pressure. However, no warping or torsion of the slide may occur here. These requirements are very high especially for cutting tools for which a stiffness must be guaranteed in the extended (working) position with said existing transverse loads for which the lateral excursion is less than 0,02 mm.  
         [0035]    For meeting these heavy-load precision requirements, not least there is a special sliding guide  12  which is placed in the gap between the slide  10  and the housing  11 . This sliding guide is preferably produced by a casting process.  
         [0036]    The particularity according to the invention of the linear path slide represented in FIG. 1 consists in that the hydraulic driving gear is integrated into the slide  10 . A blind hole is on the rear side of the slide  10 , i.e. on the surface opposite the mounting surface  16 . The slide  10  constitutes with the blind hole the cylinder of a hydraulic driving gear, a piston  24  with a piston rod  31  being placed in the blind hole and delimiting the hydraulic working space  13  together with the blind hole.  
         [0037]    Feeding pipes  14  for the hydraulic oil as well as a limit stop sensor  19  are placed on the rear side of the linear path slide  100 . These elements will be explained in more detail with reference to FIG. 2.  
         [0038]    [0038]FIG. 2 shows an enlarged view of the structure of the hydraulic driving gear integrated into the slide  10 . In the representation, the housing  11  has been uncovered and a section has been made in the upper part of the figure along the center axle. Substantially the portion of the slide  10  with the blind hole is represented. The piston  24  is movably placed (along the horizontal longitudinal axis in FIG. 2) in the blind hole. The piston  24  has a continuous groove  25  on its outer periphery, groove in which there are a piston packing and guiding bands. Thus, a tight hydraulic working space  13  is constituted between the piston  24  and the slide  10 .  
         [0039]    The piston  24  is placed fixed at the end of a piston rod  31 . The piston rod  31  is itself fixed connected with the housing  11  and projects at the rear end over the rear wall of the housing  11 , the so-called piston rod lock  32 . Two oil connecting flanges  14  are placed on this protruding end of the piston rod  31  and are locked with a tension loaded tensioning nut  22 . Moreover, the piston rod  31  has a central bore hole  27  along its longitudinal axis. This bore hole  27  is closed at the rear end (on the right in FIG. 2) by the tensioning nut  22 . Furthermore, two radial bore holes  21  are placed on the rear end of the piston rod  31  which projects from the housing  11 , bore holes which come to rest under the oil connecting flanges  14  and serve for the passing of hydraulic oil into the central bore hole  27 .  
         [0040]    At the other end of the piston rod  31  to which the piston  24  is fixed (on the left in FIG. 2), the central bore hole  27  with the smaller cross-section is continued through the piston and thus constitutes the oil outlet  23  into the working space  13 . Furthermore, a pipe  28  is placed as a central oil duct parallel to the center axle of the piston rod  31 . This pipe leads at its front end sealed into the oil outlet  23  in the piston  24  and is sealed at its rear end (on the right in FIG. 2) with a sealing  33  relatively to the wall of the central bore hole  27 . Thus, a feeding pipe for hydraulic oil which is tight all around is created which begins at the one rear oil connecting flange  14  and through the rear oil feeding bore hole  21  and the inside of the pipe  28  to the working space  13 . A pressure is generated in the hydraulic working space  13  by the passing of hydraulic oil along this path. The device reacts to this pressure with a translating of the slide  10  in the extension direction (on the left in FIG. 2, compare arrow in FIG. 1).  
         [0041]    Thus, an extension of the slide  10  can be hydraulically effected with the above described device. On the other hand, a running back of the slide  10  should take place either passively or should be caused by a depression in the working space  13 . On the other hand, for improving the force development and the controllability of the running back of the slide  10 , a second hydraulic working space  29  is provided for in this embodiment. This second working space  29  is constituted between the rear side of the piston  24 , the outside of the piston rod  31 , the inner wall of the blind hole in the slide  10  and the front side of a piston rod sealing nut  30  (provided with sealing scraper and guiding bands). This working space  29  has thus the shape of an annular gap around the piston rod  31 .  
         [0042]    The piston rod sealing nut  30  is fixedly connected with the slide  10  and placed at its rear end at the entrance of the blind hole. It thus closes the blind hole up to a central opening through which the piston rod  31  is guided. The sealing nut  30  is not placed even with the end of the slide but on the contrary the slide has a projection  20  over the sealing nut. Thus, the projection  20  constitutes a limit stop for the completely withdrawn slide. The sealing nut  30  sits slidingly movable around the piston rod  31  and is sealed with packings against the piston rod. From the front one of the two oil connecting flanges  14 , the front one of the two radial bore holes  21  leads into an annular gap which is constituted between the outer wall of the pipe  28  and the inner wall of the blind hole bore hole  27 . This annular gap leads at its front end over a radial bore hole  26  through the piston rod  31  into the working space  29 . Thus, hydraulic oil can be fed to the working space  29  on this way. An introduction of hydraulic oil causes then an increase of pressure in the working space  29  which is translated as a return force onto the slide  10  over the sealing nut  30 . The slide  10  can thus be actively run-in.  
         [0043]    The housing  11  is closed on its rear side by the piston rod lock  32 . The piston rod lock is fixedly screwed with the housing  11 . Furthermore, it has a central breaking-through through which the piston rod  31  is guided. The piston rod lock  32  thus separates the inner side of the linear path slide from the outside. Moreover, two bore holes preferably offset by 90° are made in the piston rod lock  32 , the sensor  19  for the limit stop of the slide  10  being placed in one of the bore holes and the second bore hole serving to the aeration of the rear slide free space. The use of bore holes for the end position sensor or as aeration opening can alternatively ensue depending on the constructional conditions due to the surroundings. The projecting end of the sensor  19  and the cable connection or the plug connection are for the selected arrangement at a protected place and are thus protected from damages. If the bore hole remains free as an aeration opening, it can be closed with a sieve stopper. Additionally, it can also be provided with an adsorbing element in order to collect even a small quantity of leaking oil. In this way, a complete contamination freedom (for product parts) by hydraulic leaking oil can be guaranteed.  
         [0044]    Besides the rear end position sensor  19 , a switch rod with an adjustable switch cam can be additionally mounted on the slide  10  for the recognition of the front end position, this switch rod being guided to the rear side by a further bore hole in the piston rod lock  32  and the switch cam of which being scanned by a further initiator.  
         [0045]    Both oil connections  14  are designed as free rotatable flanges and can thus be swivelled for the mounting in any direction. Both flanges are preferably of the same construction. They can be provided with additional throttle screws for the control of the rate of flow.  
         [0046]    The pressure oil feeding to the working spaces  13  and  29  preferably takes place in the represented manner through a central continuous bore hole  27  in the piston rod  31  in which a central pipe  28  with sealing is additionally introduced in order to feed the main working space  13  in the piston bottom. For appropriate bigger piston rod diameters, two separate deep hole bore holes can however be provided instead of the concentrical oil feeding. Furthermore, by selecting appropriate piston rod diameters, a special quick motion behaviour for the return stroke can be constructionally provided for.  
         [0047]    The slide housing  11  has no (lateral) breaking-through or openings so that its stiffness is increased and the production costs are reduced. The additional stiffness reserves can also be used for reducing the weight of the device. Furthermore, the missing of breaking-through openings facilitates the placing-in by casting of the sliding bearing layer  12  and the processing thereof. The simple structure of the housing allows its manufacturing as a continuous casting profile or as a continuous extruded profile. The same tools for the unmachined parts can be used for different stroke lengths. The making available of special lengths is also possible by simply shortening the housing and the slide of the next bigger version.  
         [0048]    Rear views of alternatives of the linear path slide are represented in FIGS.  3  to  5 .  
         [0049]    [0049]FIG. 3 shows a version for which the housing  11  has a bottom flange which is provided with bore holes  17  for fastening screws and dowel pins. Alternatively or additionally to the represented bottom flange placed on the longitudinal side of the housing  11 , the housing can also be provided with a front flange which is preferably placed on the outlet side of the slide,  
         [0050]    [0050]FIG. 4 shows an alternative housing  11  without bottom flange which has continuous bore holes  34  for through fastening screws in the side walls.  
         [0051]    A type of fixing the piston rod lock  35  which is an alternative to the screwing is represented in FIG. 5. The housing  11  has a square opening on its rear side which widens to a cylinder to the inside, the diameter of the cylinder lying between the side length and the diagonal of the square. The piston rod lock  35  has a square basic shape (with rounded corners) which is adapted to the rear side of the housing  11  just because of the square opening. The piston rod lock  35  can thus be inserted through the square opening into the inside of the housing  11 . As soon as it reaches the area of the cylindrical widening, it twists about 45° so that its corners  36  lie in the art of a bayonet-type locking behind the side middles of the rear square opening in the housing  11  which project over the cylinder wall. In this position, the piston rod lock  35  cannot thus move out of the housing  11 . It is locked in this position by means of a locking screw  37  which is guided through the wall of the housing  11  to a corner of the piston rod lock  35 . This arrangement has the advantage that the device can be dismantled by loosening a single screw  37  and twisting the piston rod lock  35  about 45°.  
         [0052]    The complete movable unit can be removed “to the back” after having released the piston rod lock  35  (or  32 ). The plug/turn connection described with reference to FIG. 5 can also be designed as a multiple indenting.  
         [0053]    In FIG. 6, an alternative configuration of the linear path slide  100  is represented in a partially opened top view similar to FIG. 1. The elements with the same construction as in the preceding configurations are designated with the same reference numerals and do not need to be explained again.  
         [0054]    The decisive change in this configuration consists in that the hydraulic cylinder is no longer formed directly by the inner wall of the blind bore hole of the stemple but by a separate cylinder bush  38 . This cylinder bush is placed in the blind hole and fixed to the stemple  10  for example by a screwed connection. The cylinder bush  38  is closed at its entrance opening by a sealing nut  30  so that both hydraulic working spaces are entirely formed in the cylinder bush  38 .  
         [0055]    Such an arrangement has the advantage that the hydraulic unit is entirely positioned in the cylinder bush  38  and thus can be completely dismantled from the rear side of the linear path slide  100  without the slide itself having to be removed. Tools mounted on the slide such as, for example precisely aligned cutters or the like, must not be removed. Thus, the risk of a deterioration of the sliding guide  12  due to the removal is excluded. Moreover, the hydraulic oil is encapsulated by the cylinder bush  38  and thus cannot soil the mounting place. Finally, the widening of the stemple is also avoided, since the hydraulic pressure does not act directly onto the stemple but onto the cylinder bush. This is extremely advantageous considering the anyway narrow tolerances of the slide gap.  
         [0056]    Furthermore, in the embodiment according to FIG. 6, the alternative is realized in that the hydraulic oil is guided over two parallel conduits  39  and  40  in the piston rod  31  to the rear or to the front working space.  
         [0057]    Reference Numerals  
         [0058]    [0058] 10  Slide  
         [0059]    [0059] 11  Housing  
         [0060]    [0060] 12  Sliding guide  
         [0061]    [0061] 13  Working space  
         [0062]    [0062] 14  Oil connecting flange  
         [0063]    [0063] 15  Threaded bore hole  
         [0064]    [0064] 16  Mounting surface  
         [0065]    [0065] 17  Bore hole  
         [0066]    [0066] 18  Groove  
         [0067]    [0067] 19  End position sensor  
         [0068]    [0068] 20  Projecting part  
         [0069]    [0069] 21  Radial bore hole  
         [0070]    [0070] 22  Tensioning nut  
         [0071]    [0071] 23  Oil outlet  
         [0072]    [0072] 24  Piston  
         [0073]    [0073] 25  Groove  
         [0074]    [0074] 26  Oil outlet  
         [0075]    [0075] 27  Central bore hole  
         [0076]    [0076] 28  Pipe  
         [0077]    [0077] 29  Working space  
         [0078]    [0078] 30  Sealing nut  
         [0079]    [0079] 31  Piston rod  
         [0080]    [0080] 32  Piston rod lock  
         [0081]    [0081] 33  Sealings  
         [0082]    [0082] 34  Through bore hole  
         [0083]    [0083] 35  Piston rod lock  
         [0084]    [0084] 36  Corner  
         [0085]    [0085] 37  Fastening screw  
         [0086]    [0086] 38  Cylinder bush  
         [0087]    [0087] 39  Hydraulic channel to the working space  13   
         [0088]    [0088] 40  Hydraulic channel to the working space  29   
         [0089]    [0089] 100  Linear path slide