ITMI950464A1 - DEVICE FOR FIXING A BLOWING PLUG OF A BLOWER FOR HOLLOW BODIES - Google Patents

Abstract

The invention relates to a device for fixing a blowing pin (5) of a blow molding machine for hollow bodies. The support (14) of the blowing pin, housing the blowing pin (5), is coupled with a case insert (20), which is supported in a setting plane (E), which can be moved only in all directions in one direction. case (22) can be fixed by means of a clamping device, which is represented by a clamping fork (26) and can be solicited by a drive and clamping system. The support of the insert (20) of the case with respect to the support plate (8), respectively with respect to the case (22), takes place with interposition of bearings with little friction, whereas towards the support plate (8) sliding disks (30 , 30a) are arranged floating, while a support takes place towards the bottom of the case (22)

Description

Description of the finding

The invention relates to a device for "fixing a blowing pin of a blow molding machine for hollow bodies, with a case, which can be fixed to a support plate of the blowing machine for hollow bodies and serves to support a support of the blowing pin, on the which the blowing pin is attached, wherein the blowing pin with its tip for the blowing operation protrudes into a hole of a tool which has a chamber adapted to the shape of the hollow body to be produced.

In blow molding machines for the alignment of the blowing pin with respect to the tool it is necessary to free the fixing, which usually takes place by means of internal hex screws and fixing elements in T-slots of the support plate of the blow molding machine for hollow bodies.

By carefully introducing the blowing pin into the tool, respectively lifting the tool into engagement with the blowing pin, an approximate alignment is carried out manually and subsequently, with careful tightening, the alignment is corrected again and again, until the reaching the desired working position. In this regard, it is important that a change in position can take place as a result of the fastening screws used for tightening. Furthermore, the support conditions are such that precise alignment is not possible or this is only possible with considerable operational effort. This is also accentuated when it comes to a machine with several tools arranged next to each other and blow pins. The setting effort is multiplied accordingly.

The invention has the task of realizing a device for fixing a blowing pin of a blow molding machine for hollow bodies, with which the alignment work for the blowing pin during its replacement or during the replacement of the tool is simplified and gets more precise alignment.

According to the invention, this problem is solved by the fact that the blow pin support is coupled to a case insert and is guided in a setting means, by means of which it is possible to set the height position of the blow pin support. than the case insert. In this case, the setting means preferably comprises a setting nut which can be displaced on a thread of the setting appendix of the case insert. The fundamental position can therefore be defined by means of tightening means acting on the setting nut screw. The support of the blow pin by means of a guide shaft in a hole of the housing insert is guided displacably in the direction of the axis of the blow pin, this can be done by interposing guide bushings.

An advantageous bearing of the blow pin is obtained when the box insert rests directly against the support plate and is clampable against it. However, a support in the crate is also possible.

The possibility of setting is thus favorably influenced, when it occurs with the interposition of a sliding disc or two sliding discs mutually sliding and arranged between the supporting surface of the box or the support plate and the insert of the cashier. Preferably, the sliding discs are arranged floating in a recess of the box insert. This favors the friction conditions, so that no stick-slip effect can occur in the event of a lateral shift. Friction conditions can also be favorably influenced when the sliding discs are made of a hardened steel and their sliding surfaces are ground. Furthermore, the sliding disks can be used to set the clearance relative to the displacement of the box insert in a setting plane between the bearing surface of the support plate and the box. For this purpose, sliding discs of different thicknesses can be chosen.

In order to also advantageously implement the friction conditions between the housing insert and the housing as much as possible, a low-friction bearing is arranged between these for adjustment. The bearing is preferably represented as a ball bearing, the balls of which, rolling on flat setting surfaces of the housing on one side and the housing insert on the other side, are guided in a cage. With the combination of the floating arranged sliding discs and the ball bearing practically no displacement resistance is achieved when setting the freed case insert during self-centering relative to the tool bore. This improves the setting accuracy. A hydrostatic bearing or bearing on an air cushion is also considered as a low-friction bearing.

A particularly advantageous configuration is obtained by means of a clamping device comprising a clamping fork and an actuation system, with which it is possible to stress the clamping fork. In this case the clamping fork with one end, in an orientable manner around a rotation axis crossing perpendicularly the axis of the blow pin, at a certain distance, is supported on the "case. The drive acts on the other end of the clamping fork. The case insert has two parallel slots that the clamping fork crosses with its two wings. The wings of the fork stress the support surface of the slots in the tightened state. To improve the support conditions for clamping between the fork wings and the support surfaces of the slots of the box insert, the fixing surfaces protrude with respect to the support surfaces which can be curved or arched. The support through the rotation axis is preferably carried out on the free ends of the wings The actuation device correspondingly stresses the bridge connecting the two wings of the fork where a stable unit is obtained, through which high clamping forces can be transmitted.

According to a first embodiment possibility, the actuation system can comprise a clamping screw, which with a conical surface acts on an inclined surface of the clamping fork or on a conical surface of a pin coupled with the clamping fork, whereas the screw and the pin are arranged orthogonally to each other. In this way it is possible to extract the fixing screw laterally from the case, so that its actuation for the setting operation is also advantageous, as there is good accessibility in case of limited space conditions, especially when several blowing pins are provided arranged next to each other.

However, it is also possible to provide the actuation system in the form of a fixing screw, which passes through a threaded hole in the housing and directly urges the other end of the clamping fork. In this case the fixing screw is inserted into a hole extending parallel to the axis of the blow pin. In the first embodiment, the hole in which the fixing screw is inserted extends in a plane perpendicular to the axis of the blow pin, i.e. parallel to the setting plane. It is also possible that the fixing screw (s) will directly stress the case insert and fix it against the backing plate.

Preferred embodiments of the invention are schematically represented in the drawing.

In particular:

Figure 1 shows a side view of an arrangement of a support plate on a support of the hollow body blower, with the fastener for the blow pin connected thereto,

figure 2 shows a front view on an arrangement with several blowing pins side by side, where only the support plate with the fastening device and parts of the guide for this are shown, figure 3 shows a side view with respect to figure 2 with a fastener shown in section, where the section plane contains the axis of the blow pin,

Figure 4 shows the blow pin with its tip spaced from the tool on an enlarged scale,

Figure 5 shows the blow pin in the retracted state with respect to the tool,

Figure 6 shows an enlargement of a detail referring to the support of the case insert in the case as well as the clamping device, Figures 7 and 8 show a half section and a view of the case insert as a single part, to scale of enlarged measure,

Figures 9 and 10 show two different views of the clamping fork, of which Figure 10 contains a sectional representation, on an enlarged scale, Figure 11 shows a representation corresponding to Figure 6, however with a modified clamping device with respect to to this, Figure 12 shows an enlarged representation of the case insert holder in the case, in a modified form, and

Figure 13 shows a further embodiment for the clamping support of the case insert.

Figure 1 shows a side view of a part of a blow molding machine for hollow bodies with the support 1, starting from which guide longitudinal members 2, arranged parallel to each other, extend downwards. These are coupled at their lower ends by means of a crosspiece 3. The crosspiece is designed as a plate. It carries a scraper 4 through which the blowing pin 5 extends. The blowing pin 5 has a vertical axis 6. By means of a fastening device 7 it is fixed to the guided support plate 8 which can be moved in the vertical direction on the guide beam 2. The fastening device 7 by means of screws, which engage in clamping elements, is coupled with the support plate 8. The clamping elements are movable in T-shaped slots 9, so that the fastening device 7 with the pin blower 5 can be moved, in the plane of the drawing of Figure 1, or out of this, on the support plate 8.

The fastening device 7 serves to align and fix the blow pin 5 with respect to the scraper 4, respectively with respect to the tool 11. The support plate 8 by means of a setting unit 10 is movable in the vertical direction, ie in the direction of the axis 6. The blow pin 5 in this case with its tip 13 through the scraper 4 is moved in the direction of the tool 11 in its insertion hole 12 or out of it. For the blowing operation, the tip 13 of the blowing pin is introduced into the hole 12 of the tool 11. Air is blown with the blowing pin 5 by means of fittings, to blow the extruded flexible tube, housed in the tool 11, so that to form a hollow body, as this with deformation rests on the wall of the tool chamber 11. Once the blowing operation is completed, the tool 11 is opened and the blowing pin 5 is moved upwards in the direction of its axis 6. The scraper 4 serves to scrape shaped parts that may still be attached to the blow pin 5. Figures 4 and 5 show in detail the two positions that the blowing pin 5 can assume with respect to the tool 11. Figure 4 shows the position of the blowing pin 5 at a distance from the tool 11. It is recognizable that the The tool 11 has a hole 12 which has a conical opening 34 upwards and opens into the chamber 32 downwards. The blowing pin 5 has a tip 13 of reduced diameter. The tip -13 of the blow pin- is made of a harder material than the shank of the blow pin 5 itself. It forms an interchangeable part adapted to the respective tool 11. It has a diametrical discontinuity. The edge thus formed serves as a cutting and sealing edge 33. This cutting and sealing edge 33 cooperates with the conical hole 34. In Figure 5, the blow pin 5 with its tip 13 is shown introduced into the tool the. It is recognizable that the cutting and sealing edge 33 rests in the conical hole 34. It can also be seen from this that the centering of the blow pin 5 with the cutting and sealing edge 33 with respect to the conical hole 34 is particularly important. An eccentricity would lead to an inflection of the blow pin 5 and therefore to the loss of functionality of the cutting and sealing edge 33.

In order to be able to carry out a precise setting of the blowing pin 5 with respect to the tool 11, the fixing device 7 according to the invention is provided, a first embodiment of which is shown in Figures 2, 3 and 6 with reference to Figure 1, to scale measurement once again enlarged.

In this case the support plate 8 is drawn only with a dash and dot line.

It can be seen from figure 2 that several blowing pins 5 are arranged next to each other. This is therefore a blow molding machine for hollow bodies with several tools arranged next to each other or with a forming tool with several chambers of molding arranged side by side and served at the same time.

The blowing pin 5, which can be moved along an axis 6 with its upper end, having a larger diameter, and therefore remote from the scraper 4, is housed centered on a support 14 of the blowing pin. For this purpose, its outer diameter is centered in a recess in the holder 14 of the blow pin. The blow pin support 14 has a guide shaft 15 extending along the axis 6 upwards towards the support plate 8, but ending in front of it. A fastening plate 16 is connected to the support 14 of the blowing pin towards the support plate 8, having a chamber in which a pack of springs 17 is arranged, urging a setting nut screw 18. The guide shaft 15 passes through this is the fixing plate 16 and the setting nut screw 18 and penetrates a hole in the insert 20 of the case. The setting nut 18 is provided with an internal thread and with this it is screwed onto a corresponding external thread of the setting appendix 21 of the insert 20 of the case. In this way it is possible to set the height position of the tip 13 of the blow pin. The position can be secured by means of a clamping ring 19 clamping the setting nut screw 18 on a setting appendix 21 of the insert 20 of the case. Nevertheless, the blowing pin 5 in the direction of its axis 6 can perform modest movements, which due to the effect of the grinding wheel 17 are defined with the support 14 of the blowing pin axially against it, with respect to the setting nut screw 18 and therefore with respect to the insert 20 of the case. By means of the spring 17, the blowing pin 5 with its tip 13 and in particular with its cutting and sealing edge 33 is pushed to rest with respect to the conical hole 34 of the tool 11. The insert 20 of the box is supported movably in all directions in a housing 22 in the plane of displacement E, on which the axis 6 of the blow pin 5 is perpendicular, so that an adjustment of the blow pin 5 relative to the tool 11 can take place. required setting position, the position is locked by means of a clamping device. Furthermore, from Figure 3 it is recognizable that screws 23 are provided for fixing the fastening device 7 and the relative casing 22 to the support plate 8. The casing 22 with its supporting surface 24 rests against the supporting surface 25 of the support plate. support 8. The clamping device comprises a clamping bracket 26, the two fork wings 36, 37 of which are supported in an orientation support of the casing represented by the rotation axis 27. On the other end of the clamping fork 26 acts a clamping actuation system 28 detectable in detail from Figure 6. The guide shaft 15 is guided, exactly and with ease of movement, in guide bushings 29 of the setting nut screw 18 and of the setting appendix 21.

The support of the insert 20 of the box with respect to the supporting surface 25 takes place by means of sliding discs 30, 30a. The support between the insert 20 of the casing and the casing 22 takes place by means of a bearing 31, which is a bearing with little friction and can be shaped as a ball bearing or also as another bearing that is easily movable and with little friction, for example as pneumatic support or hydrostatic support. The ease of movement defines the setting accuracy and the other centering of the blow pin 5 relative to the tool 11. The clamping device, which by means of the clamping drive system 28 can be brought into or out of the active, fixed position only this position which is essentially set automatically. It is recognizable that Cfuando several blowing pins 5 are provided in mutual arrangement side by side, with the self-centering the setting work is substantially facilitated, while in conventional embodiments it takes place exclusively by fixing the support 14 of the blowing pin on the support plate 8 by moving it into the relative T-shaped slots.

Before providing details regarding the reciprocal coupling of the clamping fork 26 and the insert 20 of the case, the relative structure is illustrated according to figures 7 to 10. Figures 7 and 8 show the insert 20 of the case . The insert 20 of the case has the setting appendix 21, provided with an external thread, and thereafter towards the top a base 54 of enlarged diameter and having a cylindrical external diameter. In this two cables 52 and 53 are obtained which are parallel to each other. The surface of the base 54, disposed upwards towards the setting appendix 21, represents a setting surface 49 cooperating with the insert of the box. In the front surface of the base 54, opposite to the setting surface 49, there is a recess 47 for housing the two sliding discs 30, 30a in a floating manner. The internal surfaces of the two slots 52, 53, arranged towards the recess 47, serve as bearing surfaces 55, 56 for the clamping fork 26 described in relation to Figures 9 and 10.

The clamping fork 26 shown in Figures 9 and 10 has two wings 36, 37 coupled together by means of the bridge 38. Furthermore, the wings 36, 37 of the fork in correspondence with their free ends have through holes 57 for their articulated fixing to the case 22. The bridge 38 has a blind hole 39. approximately centrally relative to the axial extension of the clamping fork 26 on the two wings 36, 37 of the fork there is a projection forming a fixing surface 42.

The interaction between the housing insert 20 according to FIGS. 7 and 8 and the clamping fork 26 according to FIGS. 9 and 10 with the housing 22 and the clamping drive system 28 is now illustrated in detail according to FIG. 6. From figure 6 it is recognizable that the insert 20 of the case can be displaced in the case 22 within the radial freedom of the external diameter of the setting appendix 21 in the through opening 46 of the bottom 45 of the case. The clamping bracket 26 is supported, orientable in the casing 22, with a pin, which is engaged in the holes 57 and constitutes the rotation axis 27. The insert 20 of the casing is housed between the two wings 36, 37 of the fork, wherein the wings of the fork extend through the slots 52, 53 of the insert 20 of the case. However, there is a play between both, so that a displacement is possible both in the longitudinal direction of the fork wings 36, 37 and also transversely thereto. The projections of the two wings 36, 37 of the fork with the fixing surfaces 42 face upwards in the direction of the support plate 8 and are used for clamping against the bearing surfaces 55, 56 of the slots 52 and 53. In this way the insert 20 of the box is pressed against the supporting surface 25 of the support plate 8 by means of the sliding discs 30, 30a, floating with radial clearance in the recess 47. Furthermore, the insert 20 of the box with its surface setting 49 with the interposition of a ball bearing in the form of the bearing 31 is guided on the setting surface 48 of the bottom 45 of the case. The bearing 31 comprises a cage 51, in which spheres 50 are distributed on the contour and are housed in through openings. The cage 51 with the balls 50 is movable by rolling in all directions in the recess 35 of the box 22 between the setting surfaces 48, 49. As long as the clamping drive system 28 is not fixed, following the floating support of the sliding discs 30, 30a on one side and the balls 50 on the other side, an extremely easy smoothness of movement of the case insert 20 with respect to the case 22 is obtained in the setting plane E. This ease of movement causes an extremely precise setting and a self-centering of the blow pin 5 with respect to the tool 11. The reached setting position can be fixed by clamping the clamping drive system 28 and then pressing the fastening surface 42 against the bearing surfaces 55 and 56 of the chest insert 20. In this case, the housing insert 20 is fixed relative to the support plate 8. The clamping actuation system 28 comprises a pin 40, which is engaged in the hole 39 of the bridge 38 of the clamping fork 26 and projects axially therefrom and moreover it has a conical surface 41 at its end protruding from the hole 39. The pin 40 with its axis extends substantially parallel to the axis 6 of the blow pin 5. A threaded hole 58 is arranged perpendicular to this in the case 20. This threaded hole 58 opens into a through opening 60, in which the pin 40 with its conical surface 41 also protrudes. A clamping screw 43 is screwed into the threaded hole 58, which is made as a head screw with internal hexagon and has likewise a conical surface 44 cooperating with the conical surface 41. By activating the clamping screw 43 in the direction of screwing to its conical surface 44 it stresses the conical surface 41 of the pin 40. This ta moves the clamping fork 26 in the direction of a left-handed orientation around the axis of rotation 27, so that the fixing surfaces 42 of the relative fork wings 36, 37 stress the supporting surfaces 55, 56 of the two slots 52, 52 of the insert 20 of the box and move them upwards to rest with respect to the support plate 8 and clamp them.

Figure 11 shows a variant with respect to the embodiment according to Figures 2, 3 and 6. In this case, a clamping screw 43a screwed into a threaded hole 58a is provided, which extends parallel to the axis 6 of the blow pin 5 and directly with its front surface or a corresponding annular surface acts as a clamping surface 59 on the bridge 39 of the clamping fork 26 which can be oriented around the rotation axis 27. The clamping screw 43a has a handle.

Figure 12 shows a further variant of the support for tightening the insert 20 of the box, made in two parts, in the box 22. In this case, the box 22 is formed by two parts 22a, 22b screwed together by means of screws 61 passing through spacer bushes 62, with which the two parts 22a, 22b of the case are kept mutually spaced apart.

The insert has openings, with which the spacer bushings 62 are embraced with play, so that a mobility in all directions of the insert 20 in the box 22 is ensured. The part 22a of the box formed as a plate has a recess 63, in which a disk 64 is housed, which is equipped with holes for the passage of air, distributed on the contour and has channels, respectively recesses, which are open towards the support surface on which the insert 20 of the box rests and through which it is conducting air into the gap, so that the housing insert 20, when the clamping device is free, in the form of the clamping screw 43b is slightly raised and can be easily moved in all directions on the air bearing. Then a tightening of the clamping screw takes place, which is inserted in the part 22a of the case and tightens the insert 20 of the case against the part 22b of the case. The part 22b of the case is fixed to the support plate 8.

In the embodiment shown in Figure 13, the insert 20 of the box can also be displaced in the box 22, with respect to the plane of the drawing laterally and out, respectively in the plane of the drawing, in all directions. Mounted in the case 22 is a sliding disk 30b, against which the insert -20 of the case rests. The insert 20 of the box by means of tension springs 65 is kept in contact with the sliding disk 30b. The clamping device comprises a clamping plate 66, which by means of clamping screws 43c, which can be screwed into threaded holes of the box 22, is tightened against the insert 20 of the box, so that this is released with respect to the sliding disk 30b of the box 22. The clamping screws 43c are loosened for displacement. However, in this case the insert 20 of the body by means of the tension springs 65 is kept in contact with the sliding disk 30b and nevertheless, following the suspension, it can be displaced in all directions along the sliding disk 30b, to a limited extent, in the case 22. once the exact setting position has been reached, the clamping screws 43c are tightened.

Legend

Support

Guide rails

Crossbar

Scraper

Blow plug

Blow pin axis Fastener

Support plate

T-slots

Setting unit

Tool

Hole

Blow pin tip Blow pin holder Guide shaft

Fixing plate

Spring / spring pack

Setting nut

Clamping ring

Case insert

Setting appendix

Case / parts of the case

Screws

Support surface

Support surface

Clamping fork

Rotation axis

Drive and clamping system Guide bushings

Sliding discs

Bearing

Room

Edge

Conical hole

Re-entry in the box

Fork wing

Jumper

Blind hole

Plug

Conical surface

Fixing surface

Tightening screw

Conical surface

Fund of the case

Through opening

Recess

Setting surface on the bottom of the case

Setting surface on the case insert

Spheres

Cage

Quarry

Base

Support surface

Hole

threaded hole

Clamping surface

Through openings

Lives

Spacer bushing

Notch

Disk

Spring

Clamping plate

Setting plan

setting plane, with respect to which the axis of the blowing pin is perpendicular, which can be limited in all directions with respect to the case, and by the fact that the case is associated with a clamping device acting on the insert of the case, so that the pin can be fixed in its respective setting position in the setting plane.

In this embodiment it is advantageous that the blow pin can automatically align itself with the movement towards the tool bore, and precisely in all directions. The clamping device can then be operated so that the box insert is fixed in its position. In this way, the position of the blowing pin relative to the tool is also defined at the same time.

According to a first variant, it is possible that the housing insert is coupled in a single piece with the support of the blow pin. However, the blow pin holder, which can be displaced in the direction of the blow pin axis, is preferably coupled to the housing insert. To limit the contact force of the blow pin in the tool bore, the blow pin holder is supported movably against a pressure spring. To be able to set the fundamental position are provided

Claims (20)

Claims 1. Device for fixing a blow pin (5) of a hollow body blower, with a housing (22), which can be fixed on a support plate (8) of the hollow body blower and serves to support a support ( 14) of the blowing pin, on which the blowing pin (5) is fixed, where the blowing pin (5) with its tip for the blowing operation penetrates a hole (12) of a tool (11) having a chamber (32) adapted to the shape of the hollow body to be produced, characterized in that the support (14) of the blow pin is coupled with an insert (20) of the case and is guided, movable to a limited extent in all directions with respect to the casing (22), in a setting plane (£) perpendicular to the axis (6) of the blowing pin (5), and by the fact that a clamping device (26, 43, 43A) is associated with the casing (22) which acts on the insert (20) of the case, so that the blow pin (5) can be fixed in its respective position setting in the setting plane (E). 2. Device according to claim 1, characterized in that the housing insert (20) is coupled in one piece with the support (14) of the blow pin. Device according to claim 1, characterized in that the support (14) of the blow pin, which can be moved in the direction of the axis (6) of the blow pin (5), is coupled to the insert (20) of the housing . Device according to claim 3, characterized in that the support (14) of the blow pin is supported movably against a pressure spring (17). Device according to one of claims 3 or 4, characterized in that setting means (28, 21) are provided, with which it is possible to set the basic position of the support (14) of the blow pin relative to the insert (20 ) of the case. 6. Device according to claim 5, characterized in that the setting means comprise a setting nut (18) which can be moved on a thread of a setting appendix (21) of the insert (20) of the case. 7. Device according to claim 3 / characterized in that the support (14) of the blow pin by means of a guide shaft (15) is guided in a displaceable hole in the insert (20) of the housing in the direction of the shaft (6) of the blow pin (5). Device according to one of claims 1 to 7, characterized in that the housing insert (20) is supported and clampable against the housing (22) or against the support plate (8). 9. Device according to claim 8, characterized in that the bearing takes place with the interposition of a sliding disc or of two sliding discs (30, 30A) mutually sliding. Device according to claim 9, characterized in that the sliding discs (30, 30A) are arranged floating in a recess (47) of the insert (20) of the case. Device according to one of claims 9 or 10, characterized in that the sliding discs (30, 30A) are made of hardened steel and their sliding surfaces are ground. Device according to claim 1, characterized in that the housing insert (20) for displacement on the housing (22) is supported by a low-friction bearing (31). Device according to claim 12, characterized in that the bearing (31) is represented by a ball bearing, the balls (50) of which rolling primarily on setting surfaces (48, 49) of the housing (22) and secondly in the insert (20) of the case, they are guided in a cage (51). Device according to claim 1, characterized in that the clamping device comprises a clamping fork (26) and an actuation system, and that the clamping fork (26) can be swiveled with one end around a rotation axis (27), spaced and at right angles crossing the axis (6) of the blow pin (5), is supported on the casing (22), and that the actuation system acts on the other end of the clamping fork (26) , and that the insert (20) of the case has two parallel slots (52, 53} -, which the clamping fork (26) passes through with lateral play with its two wings (36, 37) and these in the tightened state stress the bearing surfaces (55, 56} of the quarries (52, 53). 15. Device according to claim 14, characterized in that the wings (36, 37) of the fork have fixing surfaces (42) projecting with respect to the supporting surface (55, 56). 16. Device according to claim 14, characterized in that the fastening surfaces (42) are made convex or arched. 17. Device according to claim 14, characterized in that the free ends of the wings (36, 37) of the fork represent one end of the clamping fork (26). 18. Device according to claim 14, characterized in that the drive system comprises a fixing screw (43), which with a conical surface (45) presses an inclined surface of the clamping fork (26) or a conical surface ( 41) of a pin (40) coupled with the clamping fork (26), wherein the fixing screw (43) and the pin (44) are arranged perpendicular to each other. 19. Device according to claim 14, characterized in that the actuation system comprises a fixing screw (43a), which passes through a threaded hole (58a) of the housing (22) and directly urges the other end of the clamping fork ( 26) or the case insert (20). Device according to claim 12, characterized in that the bearing (31) comprises a chamber for biasing a pressurized fluid, especially air, to reduce friction.