WO1984003661A1

WO1984003661A1 - Extrusion press

Info

Publication number: WO1984003661A1
Application number: PCT/AT1984/000002
Authority: WO
Inventors: Raimund Falkner
Original assignee: Pfeifer Oskar; Raimund Falkner
Priority date: 1983-03-17
Filing date: 1984-02-10
Publication date: 1984-09-27
Also published as: AU2493684A; EP0141821B1; EP0141821A1; DE3466190D1; ATE29690T1

Abstract

In a screw extrusion press intended to form briquettes from fuel wastes of different compositions, having a press cylinder (3) and a mouth-piece (4) connected thereto, the tapered compression segment (9) of the press screw (7) is provided outside the press cylinder (3) exclusively in the mouth-piece (4) which is provided with mantle segments (11, 12) separated by longitudinal slots (13). In the tapered compression segment (9) is inserted into one of the longitudinal slots (3) a longitudinal guiding element (15) provided for the extrusion in the course of formation and engaged in the press screw (7). Preferably, two mantle segments (11, 12) are provided, of which one (12) is axially and movably guided towards the press cylinder (3). The partial cross-sectional bearings are provided between the mouth piece (4) and the press cylinder (3) beyond the compression segment (9) in the feed section (8) of the press screw (7), wherein is further conveyed the bulk material used to form the briquettes. The moving mantle segment (12) may be widened at the outlet end (41), the displacement and the widening reacting with counter-action effects to two spring-loaded regulation devices (5, 6) which are preferably independent from each other.

Description

Extrusion press

The invention relates to an extrusion press with a press cylinder with a mouthpiece, the side wall of which is divided by longitudinal slots into mutually expandable shell segments, which can be axially displaced under a spring load counteracting the pressing direction and whose cross-section can be widened.

Such an extrusion press, which is described in more detail as a piston press, can be found, for example, in GB-A-904 619. It is used in particular for briquetting coal dust or the like. and has a press cylinder, the portion forming the mouthpiece, which tapers towards the outlet end, is split into at least two tongues, each of which is spread by means of a non-parallel pair of links articulated on the press frame and on the tongue upon axial displacement of the entire press cylinder . The primary compression area of the Preßzyl nöers ein2 is a closed sleeve that moves axially against a coaxial return spring with increasing pressure. Another piston extrusion press can also be found in GB-A-656 796, in which the axially displaceable press cylinder is composed of four quarter shells, each quarter shell having a wedge-shaped outer surface which can be moved along wedge-shaped counter-surface spring-loaded, so that an axially parallel expansion occurs of the entire press cylinder is possible. Such a principle of the expandable outlet cross-section of the mouthpiece can presumably be used in piston extrusion presses without any particular malfunctions, since when compressing the material, essentially only axial compression pressures are applied. will kick. With screw presses, which are only marginally mentioned in GB-A-904 619 as a possible variant, the phenomenon occurs in the compression zone that the screw no longer conveys the pressed material, but simply rotates it, since between the material and the screw tube wall there is only a frictional engagement that breaks after a certain compression. In order to remedy this disadvantage, a number of proposed solutions have already become known (DE-A-27 36 810,

GB-A-1034/1909, GB-A-12 27 548, DE-C-814 098), according to which, in particular in the compression section in an axial plane of the press screw, at least one longitudinal guide element engaging and moving with it, in particular one toothed disc, is stored in the press cylinder.

For the compression of the material, the introduction of a back pressure is necessary, which takes place in the piston extrusion press mentioned at the beginning by the tapering of the mouthpiece, which has to be spread apart. In principle, two different types of counterpressure injection are possible with screw presses. On the one hand, a separate counterpressure device can be formed at the outlet end of the mouthpiece, which deviates axially when a certain pressing pressure is exceeded (for example according to DE-A-27 36 810), or the press screw is equipped with a compression section in which the screw is conical runs, or the incline of the screw flights is reduced. The latter more or less precludes toothed guide elements engaging in the screw flights in the compression section. In all cases, the axial displacement of the mouthpiece presents difficulties, since * neither the changeability of the outlet cross-section nor the longitudinal guidance of the material can be dispensed with in the compression section. When trying to combine a longitudinally displaceable and thereby expanding mouthpiece on the press cylinder of a screw press with toothed longitudinal guide elements, recurring malfunctions occurred by the screw press becoming blocked, which made it difficult to disassemble and clean.

The out _. the brick screw press known from US-A-756 906 with a fixed press cylinder and axially displaceable mouthpiece, the press screw tapering conically, does not provide a solution to this problem precisely. There the mouthpiece touches the end of the press cylinder, both of which end in an annular cutting edge. When the mouthpiece is returned to the press cylinder, the cutting edges should cut off the material that is freely released on the side. This may be the case with supple raw clay, which has excellent pressing properties, and a manageable one only after drying and firing

Product provides a simple, acceptable solution, however ____e is in no way suitable for pressing waste in particular.

Now that the execution of a solution that functions essentially trouble-free even in long-term operation and that was able to find the resumption of briquetting despite the graft remaining in the mouthpiece after a long standstill, the reasons for the permanent malfunctions seem to be looked back to lie in the unavoidable change in diameter between the compression section of the press cylinder and the mouthpiece, which must either be slidably arranged on or in this. Is the mouthpiece on the end of the outside When the press cylinder is pushed on, there is a sudden expansion of the cross section after the material compression, so that there is no support of the resulting strand in this area, which can break out due to the axial counter pressure, which is particularly the case when compressing combustible materials Waste, which has different compositions and moisture content, always results.

If the mouthpiece is pushed into the press cylinder, a cross-sectional tapering results, the overcoming of which requires high back pressures, but therefore also high press pressures, and a construction which is unnecessarily massive, with high drive power.

It is therefore an object of the invention, an extruder of the type mentioned form as a screw extruder, which is insbesondere- suitable for briquetting of combustible waste, in which expandable from the displaceability shell ^segments' of the mouthpiece no problems in terms of strength strength ness of the briquettes and the Susceptibility to failure.

According to the invention, this is now achieved in that in the case of a design as a screw press, the press screw of which is provided with a feed section and a compression section, the compression section protrudes from the mouth end of the press cylinder and that the shell segments of the mouthpiece extend to the other side of the compression section, a longitudinal guide element engaging in the press screw being arranged in at least one of the longitudinal slots in the compression section. The solution according to the invention relocates the cross-section jump which is inevitable in the case of an arrangement of the two approximately cylindrical parts which can be pushed into one another, into the feed section of the press screw, in which there is still no pressing pressure. The compression section therefore lies completely in the mouthpiece, the cross-section of which has no sudden change, so that the resulting strand is subjected to essentially the same or uniformly changing feed conditions until it emerges from the mouthpiece.

Both conceivable execution options lead to the desired success, i.e. the mouthpiece can be pushed onto the outside of the press cylinder. However, the mouthpiece can also be inserted into the press cylinder. In both cases, the compression section of the press screw lies exclusively in the mouthpiece. Even when inserting. There are no problems with the mouthpiece in the press cylinder, since when the spring-loaded jacket segments are returned after their expansion or extension, the ends arranged in the press cylinder only have to displace loose material. The shell segments are in particular formed by half-shells.

A preferred embodiment, which provides a particularly simple construction of the screw press, provides that the mouthpiece is formed from two shell segments, one of which is rigidly connected to the press frame and the other is axially displaceable and radially expandable on the press frame . This means that there is now only the need to provide a guide and holding part for a single sheath segment, it having been shown that the choice of which of the two sheath segments is to be provided in a displaceable and spreadable manner is made by Direction of rotation of the press screw is affected. For example, when the press screw rotates clockwise, which in this case must have left-handed screw flights, the longitudinal guide element is pressurized on its left side. It is therefore expedient to arrange the jacket segment lying on the pressurized side of the longitudinal guide element in a spreadable manner. This can at the same time also provide support for the compression section of the press screw, which otherwise cannot be stored and which rests on the shell segment rigidly connected to the press frame.

According to GB-A-904 619 mentioned in the introduction, a non-parallel pair of links is provided for each displaceable and expandable casing segment, which is articulated on four hinge bolts on the casing segment and the press frame. The axial displacement of the jacket segment causes it to spread. Since it has now been shown that the extent of the spread would have to be smaller or larger under certain conditions in order to achieve an approximately uniform strength of the strand and to rule out blockages, particularly after downtimes, a preferred embodiment provides that the handlebar closer to the outlet opening in an abutment of the press frame is mounted, the distance to the second, fixed abutment can be changed. By this Aus¬ formation, is arranged in, for example, the variable abutment at one on the press frame swivel-mounted lever, whose pivot axis senk¬ right to the axis of the mouthpiece is aligned _etc. are dependent upon the building up in the mouthpiece pressure a mere axial displacement, a mere spread and a combination of displacement that automatically sets itself in any ratio and spread possible. A particularly simple embodiment avoids hinge pins on the links in that each link is pivotally mounted in the grooves of the axially shifting jacket segment and one of the abutments belonging to the press frame. The links are formed, for example, by flat elements with rounded narrow sides which engage in the grooves.

The spring loading of the jacket segment is preferably carried out via the handlebars. For this purpose, it is provided in one embodiment that a one-armed lever extends from each link approximately parallel to the mouthpiece in the direction of the outlet end and is articulated on a guide part which acts essentially perpendicularly to the axis of the mouthpiece by a compression spring which is supported on the press frame . If one of the two jacket segments is rigidly connected to the press frame, it can be used as a frame-like abutment for the compression spring, so that each single-arm lever can consist of two arms fixed on both sides of the handlebar, and the guide part by one Mouthpiece surrounding U-shaped bracket is formed, the central web acts on the compression spring. Another possibility for guiding each displaceable and expandable jacket segment is that two pairs of guide parts are successively provided in the axial direction between the press frame and the axially displaceable and radially expandable jacket segment, the guide surfaces of which diverge on the outlet opening side, the divergence of the guide surface closer to the outlet opening-side end of the mouthpiece.

-gTΪREX

OMPI ty ^ WIPO In this case, the guide parts arranged on the displaceable jacket segment preferably have plane guide surfaces which roll on roller bearings arranged on the press frame. In this embodiment too, the roller bearing closer to the outlet opening can be rotated at its axial distance from the second roller bearing, for example it can be arranged on a pivotable bracket in order to achieve a spreading of the shell segment that is independent of the axial displacement.

The longitudinal guide element inserted into the longitudinal slot between the jacket segments can be formed, for example, by a toothed disk or by engagement elements arranged on an endless chain. A further possibility provides for the guide element to be composed of rolling elements which are loosely lined up and run around in the axial plane of the press screw. If the rolling elements are formed by balls, so that essentially a cage-free ball bearing is used, the advantages known from the ball bearing of more favorable absorption of the forces acting obliquely to the pressing direction result. The section of the longitudinal slot traversed by the balls is widened in this case, the ball diameter corresponding to the pitch of the compression section.

The longitudinal slots between the shell segments not only serve to enable the expansion, but also fulfill a further task in the screw press according to the invention,

By taking over the further longitudinal guidance of the strand formed on the longitudinal guide element until it emerges from the mouthpiece. When compaction occurs at the end of the longitudinal guide element, the material to be compressed also into the longitudinal slots, so that a rib is also formed on the strand through each longitudinal slot. In order to achieve an approximately uniform compaction in the entire cross-sectional area, an end section which tapers into a tip preferably adjoins the compression section of the press screw, in which the pitch of the screw flights is smaller or decreases continuously. As a result, the material is also fed and compressed into the core region of the strand, into which no material can be introduced in the compression section itself. The strand emerging from the mouthpiece is divided into pieces of suitable length, or also breaks into them, due to its weight, which increases with increasing outlet length.

The invention will now be described in more detail below with reference to the figures in the accompanying drawings, without being limited thereto. Show it:

1 shows a schematic side view of a screw press according to the invention for briquetting particularly combustible waste, FIG. 2 shows a horizontal section along the line II-II of FIG. 1,

3 to 6 cross sections corresponding to lines III-III IV-IV, V-V and VI-VI of Fig. 2,

7 shows a vertical section along line VII-VII of FIG. 2, FIG. 8 shows a horizontal section according to FIG. 2 in a spread position of the mouthpiece, FIG. 9 shows a horizontal section with a partial top view according to line IX-IX of FIG 1, and FIG. 10 shows a horizontal section according to FIG. 2 through the mouthpiece of a second embodiment.

-g SE OMPI According to FIG. 1, a screw press has a press frame 1 with a press cylinder 3, a mouthpiece 4 and a filling funnel 2 serving to feed the material. As can be seen in detail from FIGS. 2 to 8, the press screw 7 is composed of a cylindrical feed section 8, which begins below the filling funnel 2 and in which the screw-type slugs have a large incline, and a subsequent, tapering compression section 9. in which the incline of the screw flights is smaller, and together from an end section 10 running into a tip, in which the slope of the screw flights is reduced again. The mouthpiece 4 adjoins the press cylinder 3, which comprises at most the feed section 8 of the press screw 7, the compression section 9 completely projecting beyond the press cylinder 3 being located within the mouthpiece 4. In the exemplary embodiment, the mouthpiece 4 is composed of two jacket segments 11, 12 formed by half-shells, which are separated over the entire length by two longitudinal slots 13, to which they terminate in cutting edges 50. At the end of the mouthpiece 4 on the press cylinder side, an end plate 36 is provided, which is connected to the press cylinder 3 and thus to the press frame 1. The shell segment 11 is rigidly connected to the end plate 36, on the other hand, the second shell segment 12, as can be seen from the double arrows in FIG outlet-side end 41 is spreadable. The movable jacket segment 12 is assigned two control devices 5, 6, of which the control device 6 closer to the outlet-side end 41 is axially adjustable in its entirety, as will be explained below.

^• ^ δsi_ In the area of the tapering sealing section 9, the mouthpiece 4 widens to the press cylinder 3 to form a funnel 37, as can be seen in particular from FIGS. 2, 3 and 7. One of the two is in the end section 38 (FIG. 3) on the press cylinder side

Longitudinal slots 13 a longitudinal guide element 15 is used, which consists of a housing and therein in a circular or oval guide track around a core 39 loose, gap-free filled rolling elements 16, in particular balls. The balls constantly engage in at least one screw flight in the compression section 9 and are circulated in their guideway by the screw rotation. The pitch in the compression section 9 preferably corresponds to the ball diameter and the pitch depth approximately to the ball radius.

If the press screw 7 is left-handed, so that it must be driven in the right-hand direction for conveying and compacting, the material to be pressed acts on the left side of the rolling elements 16 in FIG. 3. The rolling elements are thereby pressed to the right onto the jacket segment 11, which is rigidly fastened in the press frame 1. Due to its rigid fastening, the casing segment 11 also forms a support for the compression section 9 of the press screw 7, which is also fastened in the direction of the casing segment 11. In order to relieve the pressure on the mouthpiece when the compression pressure is too high, the jacket segment 12 on the left in FIG. An excessive compression pressure is reduced without intermediate elements or the like directly via the movable shell segment 12. The longitudinal slots 13 between the two jacket segments 11, 12 are in the area close to the press cylinder 9 from each other covers parallel side plates 18 which are attached to the end plate 36. The rigid ^* shell segment 11 is connected to the side plates 18, while they limit a horizontal guide slot for the movable shell segment 12.

Each of the two control devices 5 and 6 consists of an abutment 20 and 21 assigned to the movable jacket segment 12, and an abutment 22 and 23 assigned to the press frame 1, between the

Abutments 20, 22 or 21, 23 inserted links 24 or 25, as well as parts 26 to 34 associated with them, which counteract the movement of the casing segment 12. The two abutments 20 are on the movable casing segment 12 or on an outer reinforcing strip 19, 21 formed as transverse strips, in which grooves perpendicular to the pressing direction are inserted, which serve as bearing surfaces for each of the links 24, 25. The links 24, 25 are each formed by a flat element, etv / a a flat profile web, the narrow edges engaging in the grooves are rounded. The abutments 22, 23 assigned to the press cylinder have the same bearing grooves for the links 24, 25 and form a central web of U-shaped brackets 33, 27. The end portions of the links 24, 25 protrude through openings in the side parts of the brackets 33, 27; arms 26 of a single-armed lever, which extends approximately parallel to the central segment 12, are fastened in a rotationally fixed manner thereon, at the free ends of which a U-shaped guide part 28 including the mouthpiece 4 is articulated. The connecting web 32 of each guide part 28 is penetrated centrally by an adjusting screw 31 which bears against a pressure plate 29 via a pressure plate, which in turn is supported on the outside of the rigid shell segment 11 essentially radially to the screw axis 35. The axial gTTRE

OMP Limitation of the guide part 28 with compression spring 29 is achieved by two limiting bodies 30 arranged on the rigid jacket segment 11. The bracket 33 of the control device 5 near the press cylinder is firmly connected with its side parts to the side plates 18, so that its abutment 22 is rigidly arranged with respect to the press frame 1. Since the control device 6 is provided near the exit end 41 of the mouthpiece 4, is to have a larger space than ^• it can be achieved with a rigid coupling with the control device 5, the two side parts of the bracket are extended 27 of the control device 6 and extending transversely via the side plates 18. On these, they are articulated on a bolt 34 beyond the rigid shell segment 11. The side parts of the bracket 27 and the

Guide part 28 extend substantially parallel. The two links 24, 25 are at rest with different inclinations to the pivot axis 35, the angle to a cross-sectional plane is, for example, 10 ° to 15 ° for the link 24, and at least 30 ° for the link 25. If the pressing pressure building up in the mouthpiece 4 through the sealing section 9 now exceeds the desired or required extent and can be adjusted with the aid of the adjusting screws 31, then an evasive movement of the movable shell segment 12 begins, which is either exclusively axial, exclusively radial , but usually will be a combination of both, but there is no specific ratio. If the jacket segment 12 is axially entrained, the inclined position of the two links 24, 25 is increased and the arms 26 connected therewith are turned outward, the compression spring 29 being compressed between the articulated guide parts 28 and the rigid jacket segment 11. If there is no or too little expansion of the outlet-side end 41 of the mouthpiece, then under the effect of the pressure Spring 29 of the control device 6 of the bracket 27 slightly towards the exit end, the inclined position of the link 27 being reduced. In the normal case, however, an expansion of the movable jacket segment 12 caused by the compression pressure will also occur with the axial displacement. If the displacement causes the extent of the spread which would be given with a rigid arrangement of the bracket 27, the bracket 27 of the control device 6 does not pivot, on the other hand a larger spread is required, the impossibility of which was responsible for the blockages which occurred in the prior art, so the bracket 27 is pivoted cylinder ^presses' side, increases 25 wherein the inclination of the link (shown exaggerated in Fig. 8).

Since the press cylinder-side ends of the jacket segments 11, 12 in the press cylinder 3 beyond the compression section 9, i.e. lie in the end part of the feed section 8, the return of the expanded, advanced jacket segment 12 is possible without difficulty, since its end face can move without resistance in the feed section 8, which is only loosely filled with the material. The shell segments 11, 12 consist in particular of a corrosion-resistant material, so that even when the screw press is at a long standstill, the plug remaining in the mouthpiece 4 does not bind to the shell segments 11, 12, and the screw press can be put into operation again without difficulty. A variant of the mouthpiece structure is shown in the embodiment according to FIG. 10. Instead of the abutment with handlebars, two guide parts 42, 43 provided with guide surfaces 44, 45 of different inclination are attached to the movable jacket segment 12 in this embodiment. In this embodiment, the press frame 1 is assigned two roller bearings 46, 47, which, when the casing segment 12 is axially displaced, on the guide

OMPI unroll surfaces 44.45. The guide surface 45 closer to the outlet end 11 is limited by flange-like projections, an adjustable compression spring 49 extending in the axial direction being supported on the projection 48 on the outlet end. The representation according to Fig. 10 should be understood to mean only schematically in the ^'essential. It would also be self-evident in this embodiment, too, to design the control device 6 closer to the outlet end 41 at a distance from the control device 5 fixed to the frame, for example to arrange it on a swivel bracket in the manner described, in which case a pair of compression springs which can be used independently of one another is also used here is provided.

Another ^'conceivable embodiment would be the formation of the variable Aus¬ V / iderlagers 23 and roller bearing 47 on an adjustable sliding or friction bearing piece in the axial direction.

In the area cut horizontally in FIG. 9 through the lower part of the filling funnel 2, and in FIG. 7, a wing 40 rotatable about its longitudinal axis is arranged at least on one side laterally above the feed section 8 of the press screw 7 and rotatable parallel to the press screw 7. The wing 40 is made, for example, of rubber or rubber-like material and serves to avoid bridging of the material to be briquetted in the lower part of the filling funnel 2. This preferably also has a comminution device (not shown), with each stirring blade 40 and being used for the press screw 7 the

Comminution device a common drive is provided.

O PI & _? NAT1Ö

Claims

Patent claims

1. Extrusion press with a press cylinder with a mouthpiece, the side wall through longitudinal ^¬ slots in mutually expandable shell segments. 5 is divided, which is axially displaceable under a spring load counteracting the pressing direction and whose outlet cross section can be widened, characterized in that, in the case of a design as a screw press, the press screw (7) thereof

10 a feed section (8) and a

Compression section (9) is provided, the encryption ^'sealing portion (9) from the mouthpiece end of the press cylinder (3) projects, and in that the shell segments (11,12) of the mouthpiece (4)

15 extend beyond the compression section (9), a longitudinal guide element (15) engaging in the press screw (7) being arranged in at least one of the longitudinal slots (13) in the compression section (9).

202. Extrusion press according to claim 1, characterized in that the casing segments (11, 12) in the. Extend press cylinder (3).

3. Extrusion press according to claim 1 or 2, characterized in that the shell segments (11, 12) by

25 the longitudinal slots (13) are separated over their entire length, the longitudinal slots (13) on the outside of the jacket segments (11, 12) being covered in the area close to the press cylinder.

4. Extrusion press according to claim 3, characterized in that the mouthpiece (4) consists of two shell segments (11, 12)

^• JΕ T. OMPI is formed, one of which (11) is rigidly connected to the press frame (1) and the other is guided on the press frame (1) so as to be axially displaceable and radially expandable.

5 5. extrusion press according to * one of claims 1 to 4, da¬ characterized in that the shell segments (11,12) consist of a corrosion-resistant material.

6. Extrusion press according to one of claims 1 to 5, with a pair of non-parallel links

₁₀ P ^ o axially shifting shell segment, the handlebar closer to the outlet end of the mouthpiece running at a smaller angle to the axis of the mouthpiece than the other handlebar, characterized in that the outlet opening

• * L5 closer link (25) is mounted in an abutment (23) of the press frame (1), the distance to the second abutment (22) fixed to the frame can be changed.

Extrusion press according to Claim 6, characterized in that the changeable abutment (23) is arranged on a bracket (27) which can be pivoted on the press frame (1) and whose pivot axis (34) is perpendicular to the axis (35) of the mouthpiece (4 ) is aligned.

⁵ 8. extrusion press according to claim 6 or 7, characterized ge indicates that each link (24) in grooves of the axially shifting shell segment (12) 'and one of the press frame (1) belonging to the abutment (-22,23) pivotable limited is stored.

Extrusion press according to Claim 6 or 8, characterized in that a one-armed lever extends from each link (24, 25) approximately parallel to the mouthpiece (4) in the direction of the outlet end (41), which is essentially perpendicular to the i Axis (35) of the mouthpiece (4) is articulated by a guide part (28) which acts on the press frame (1) and is supported by a compression spring (29).

10. Extrusion press according to claim 4 and 9, characterized gekenn¬ characterized in that each one-armed lever consists of two on both sides of the handlebar (24, 25) fixed arms (26), and the guide part (28) through one of the mouthpiece (4) enclosing U-shaped bracket is formed, wherein the compression spring (29) is supported on the jacket segment (11) rigidly connected to the press frame (1).

11. Extrusion press according to claim 7 and 10, characterized ge indicates that the pivotable bracket (27) of the variable V / iderager (23) and the guide part (29) forming bracket in v / esenϋlicnen run parallel.

12. Extrusion press according to one of claims 1 to 4, characterized in that between the press frame (1) and the axially displaceable and radially expandable jacket segment (12) in the axial direction successively two pairs of guide parts (42,46; 43,47 ) are provided whose guide surfaces (44, 45) diverge on the outlet opening side, the divergence of the guide surface (45) closer to the outlet opening end (41) of the mouthpiece (4) being greater.

13. Extrusion press according to claim 12, characterized in that the guide parts (42, 43) arranged on the displaceable jacket segment (12) have flat guide surfaces (44, 45) which are arranged on roller bearings (46, 46) arranged on the press frame (1). 47) unroll.

14. Extrusion press according to claim 1, characterized in that the press screw (7) has a tapering to a tip end portion (10) in which the pitch of the screw flights relative to the compression section (9) is less.

15. Extrusion press according to claim 1, characterized in that the guide element (15) is composed of loosely arranged, in the axial plane of the press screw (7) rotating roller bodies (16).

16. Extrusion press according to claim 15, characterized in that ■ the rolling elements (16) are formed by balls, the section (38) of the longitudinal slots (13) traversed by the balls being widened between the casing segments (11, 12).

O PI *