Press roll

Abstract: A press roll (2) cooperable with a counter roll (1) to form a press with a long nip for paper or board machines is described, said press roll comprising two end walls (4, 5); a flexible jacket (3) secured to the end walls; support members (12, 13) for the end walls, said end walls comprising bearing means (35) for permitting rotation of the jacket and the end walls in relation to the support members; and a press shoe (15) forming together with the counter roll (1) a pressing zone. According to the invention each attachment means comprises a circular clamping member (32), which includes a wedge body (28), and a circular groove (24) disposed on the inside of the end wall to receive the edge portions (8, 9) of the jacket and the wedge body (28), the groove (24) and wedge body (28) being provided with cooperating wedge forming surfaces (25, 33; 26, 34). Further, the clamping member (32) includes bolts (29) for pulling the wedge body (28) into the groove (24) and retaining it therein in order to clamp the edge portions of the jacket by means of wedge action, against the end wall.

Description: The present invention relates to a press roll cooperable with a counter roll to form a press with a long nip for paper or board machines, said press roll comprising two end walls, a tubular, flexible, liquid-impervious jacket secured at its edge portions by means of an attachment means to peripheral portions of the end walls; stationary support members for supporting the end walls, said end walls comprising bearing means for permitting rotation of the jacket and the end walls in relation to the stationary support members about an axis of rotation; and a press shoe forming together with the counter roll a pressing zone having said long nip, the jacket upon rotation being moved through the pressing zone in sliding contact with the press shoe. Presses of the type described in the introduction are known for instance through US 4 563 245, US 4 584 059, US 4 625 376, US 4 707 222, DE 3 607 941 and DE 3 805 350. Within the pressing zone in such presses, the jacket is forced inward by means of the counter roll to said sliding contact with the press shoe. The part of the jacket pressed against the press shoe will then lie in an axial line located radially inside a line extending between the peripheral end wall portions forming the attachment locations for the edge portions of the jacket, the radial distance between these lines being between 20 and 40 mm. High local axial strains occur in the jacket due to this pressing, when the jacket passes through the pressing zone. These local strains consequently cease immediately after the jacket has left the pressing zone. The strain thus occurring repeatedly in the jacket causes not only fatigue in the material, but also causes considerable tensions at the attachment locations on the end walls and on the end wall bearings. The service life of the jacket becomes too short and both jacket and end wall bearings must be replaced regularly with consequential stoppages and loss of production. To secure the jacket to the end walls attachment means are used which include holes and/or recesses in the jacket itself for inserting bolts which by means of a clamping ring clamp the jacket against the end wall. Local strains occur at the holes and recesses which may cause the jacket to be damaged and the tension will be uneven around the circumference. Furthermore, the jacket may come loose at one or more points because the clamping ring and bolts provide insufficient clamping force to retain the jacket in the desired taut state. The use of holes and recesses in the edge portions of the jacket results in increased costs for manufacturing the jacket in accordance with carefully specified dimensions for each axial size of press roll. DE A1 3 338 487 describes special connection means diposed at the edges of the jacket and the peripheral end wall portions so that the edge portions of the jacket are axially movable in relation to the end walls. The connection means include engagement means formed directly at the edge portions of the jacket, or separate axially movable engagement elements which can bend or roll and which connect the edge portions of the jacket to the end walls via a fixed securing member, or flexible sealing elements which connect the edge portion of the jacket to the end walls via an axially movable securing member, or a combination of the two first mentioned embodiments. The use of engagement means formed in the edge portions of the jacket results in increased costs for manufacturing the jacket in accordance with carefully specified dimensions for every axial size of press roll. The use of axially movable engagement elements, which can bend or roll, results in the risk of the edge portions of the jacket being pulled out of its engagement position after repeated axial movements of the edge portions to and fro. Furthermore, all embodiments of connection means are relatively complicated to manufacture and fit. The object of the present invention is to provide a press roll with improved attachment means which secure the jacket to the end walls with sufficient force, said force also being distributed uniformly around the circumference of each edge portion of the end wall, and said securing being intact and effected without holes or the like having to be made in the flexible jacket. The jacket can consequently be manufactured and mounted in a considerably simpler manner than known jackets. This object is achived by the invention which is substantially characterized in that each attachment means for securing an edge portion of the jacket to the end wall comprises a circular clamping member, which includes a wedge body, and a circular groove disposed on the inside of the end wall to receive the edge portions of the flexible jacket and the wedge body, the groove and wedge body being provided with cooperating wedge-forming surfaces; and that the clamping member includes means for forcing the wedge body into the groove and retaining it therein in order to clamp the edge portions of the jacket by means of wedge action, against the end wall. Further preferred embodiments of the invention are defined in dependent claims 2 to 23. The invention will be described in more detail in the following with reference to the accompanying drawings. Figure 1 is a partially schematic view, primarily in vertical section, of a press roll and adjacent component of a wet press, the press roll having attachment means according to a first embodiment of the invention to secure a jacket to the press roll end walls. Figure 2 is an enlarged fragmentary sectional view of one of the attachment means according to Figure 1, in which the groove of the attachment means is formed in the adjacent end wall of the press roll. Figure 3 is an enlarged fragmentary sectional view of an attachment means according to a second embodiment wherein the groove is surrounded by an outer ring of the end wall. Figure 4 is an enlarged fragmentary sectional view of an attachment means according to Figure 3 associated with the other end wall and of the press roll and having an aid for mounting the jacket to the end wall. Figure 5 is an enlarged fragmentary sectional view of an attachment means according to a third embodiment. Figure 6 is an end view of a section of the end wall with the attachment means according to Figure 5. Figure 7 is a view similar to Figure 5 of an attachment means according to a fourth embodiment. Figure 8 is a sectional view taken substantially along the line VIII-VIII in Figure 7. Referring to Figure 1, this shows schematically parts of a wet press disposed in the wet section of a paper machine or a board machine in order to press water out of and consolidate a formed wet fibrous web 65. The wet press comprises a rotatable counter roll 1 and a press roll 2, which has a tubular reinforced jacket 3 impervious to liquid, and two opposite circular end walls 4, 5, the edge portions 8 and 9 of the jacket being connected in an air and liquid tight manner to the peripheral portions 6 and 7, respectively, of the end walls 4, 5 as will be described below. The jacket is flexible and dimensionally stable. The press roll is mounted in two stand parts 10, 11 by means of support members in the form of two stationary support pins 12, 13 with circular cross section, said support pins extending in air-tight and liquid-tight manner through central openings in the end walls 4, 5. The end walls 4, 5, jacket 3 and support pins 12, 13 thus define an air-tight and liquid-tight chamber 14 which can be placed under sufficient pressure, e.g. 0.1 bar overpressure, to displace the end walls 4, 5 apart from each other in order to keep the jacket 3 sufficiently stretched. The end walls 4, 5 are consequently axially displaceable in relation to the support pins 12, 13. Alternatively, spring means (not shown) may be disposed in the press roll, pressing against the end walls or one of them in order to stretch the jacket in axial direction. Pneumatic or hydraulic cylinders may also be utilized for this purpose, or any suitable combination of the three arrangements mentioned. The press roll 2 also comprises a press shoe 15, disposed opposite the counter roll 1 which, together with this, forms a pressing zone having a long nip within a predetermined sector of the counter roll 1, where the jacket 3 is thus pressed down against the press shoe and wraps the predetermined sector of the counter roll 1. The press shoe 15 is supported by an inner stand 16, suitably in the form of a beam secured to axially inner portions of the support pins 12, 13. Support means of suitable form, such as axial laths or strips (not shown) may be disposed on the inside of the jacket to provide support for the jacket when it is being mounted. Such support means may be attached to the inner stand 16 via suitable bracings (not shown). The fibrous web to be dewatered is enclosed between two felts 66, 67, each disposed to run in a loop over a plurality of rolls (not shown) and through said pressing zone. During operation, the continuous wet fibrous web 65 runs through the pressing zone together with the felts 66, 67, which absorb the liquid pressed out of the fibrous web. If desired, the felt 67 adjacent the counter roll 1 may be omitted so that a single-felt press is obtained. Any suitable press shoe may be used. The shoe 15 shown consists of a sliding part 17 and a frame part 18, the sliding part 17 having a slide surface along which the jacket 3 moves in sliding contact. The shoe 15 located opposite the counter roll 1 extends transversely across the jacket 3, parallel with the axis of rotation 19 of the counter roll 1 and it is the same length or slightly shorter than the length of the counter roll 1. This in turn is shorter than the press roll 2 so that inclined, indented sections 20, 21 are formed in the jacket 3, located axially outside of the counter roll, within the area for the pressing zone. In the preferred embodiment shown the press shoe 15 is connected to the stand 16 via a jack unit 22 having several jacks 23 by means of which the pressure of the press shoe 15 on the jacket 3 and the fibrous web can be controlled. A channel system (not shown) is also disposed in the press shoe 15 for the supply of lubricant to the sliding surface of the sliding part 17, thus producing and maintaining a friction-reducing film between the jacket 3 and press shoe 15. The press shoe 15 can be provided with hydrostatic pressure pockets (not shown) filled with pressure liquid acting on the inner side of the jacket 3 to compress the fibrous web in a controlled manner. The end walls 4, 5 comprises circular bearing means 35 for rotating the jacket 3 and a section 68 of each end wall located radially outside the bearing means 35 about an axis of rotation 36 which need not necessarily coincide with the central axis of the support pins 12, 13. In the embodiment shown in Figure 1 the bearing means 35 consists of rolling bearings, such as ball or roller bearings. Alternatively sliding bearings with flat or spherical sliding surfaces may be used. Further, each end wall 4, 5 comprises cylindrical sliding bearings 37 arranged to allow axial displacement of the end wall 4, 5 in relation to the support pins 12, 13. Alternatively, only one of the end walls is provided with such a sliding bearing 37 to effect axial displacement of the end wall 4 or 5. The end walls 4, 5 may include surrounding means 38, concentric with the axis of rotation 36 of the jacket and arranged to allow free axial movement of the peripheral end wall portions 6, 7 in the direction to each other and the press shoe 15 or nip region by the action of axial strains which occur in the jacket 3 upon its passage through the pressing zone. Of course, the invention is also applicable to press rolls not provided with such means 38. The edge portions 8, 9 of the jacket 3 are rigidly connected to the peripheral portions 6, 7 of the end walls to give a sufficiently strong and tight joint. The peripheral end wall portions 6, 7 are form stable and consist of a suitable metal material. The same reference numerals are utilized in the following to indicate parts and elements which are similar or substantially similar in the different embodiments. According to the invention each attachment means comprises a circular groove 24 disposed on the inside of each peripheral end wall portion 6, 7 and having two opposite side walls 25, 26 forming a small angle to each other so that the width of the groove 24, i.e. its radial extension decreases in the direction towards the bottom 27 of the groove. Said angle is typically about 5°. One of the end walls, viz. end wall 26 receives the jacket 3 and preferably extends axially (i.e., generally parallel to axis 36). Furthermore, the attachment means includes a circular clamping member 32 having a wedge body 28 the shape of which corresponds to the shape of the groove 24 so that the wedge body and the groove have cooperating wedge-forming surfaces 25, 33 and 26, 34, respectively, for clamping the edge portions 8, 9 of the jacket by wedge action. The opposite wedge forming surfaces 33, 34 of the wedge body 28 thus define a small angle with each other corresponding to said angle defined by the side walls 25, 26 of the groove 24. The clamping member 32 is provided with a plurality of axial tapped holes 30 aligned with axial holes 31 in the end wall for inserting bolts 29 therein from the outer side of the end wall and for engagement with the hole 30 of the clamping mamber. By means of the bolts 29 the wedge body 28 is forced into the groove 24 so that the edge portion 8, 9 of the jacket is clamped by increasing wedge force between the wedge body 28 and the side wall 26 of the groove. It is understood that the wedge body 28 and the groove 24 are dimensioned with respect to each other so that the wedge body does not contact the bottom 27 of the groove. In the embodiment of the attachment means illustrated in Figures 1 and 2 the groove 24 is formed by a recess in the end wall 5, 6 at a slight distance from the outer surface of the end wall. From a practical point of view, the wedge body 28 has to be disposed on the outer side of the jacket, the radially inner side wall 26 of the groove 24 thus is axially aligned in order to receive the edge portion 8, 9 of the jacket. The wedge body 28 is divided into a plurality of circular identical arc-shaped segments, e.g. 3 to 6 segments, which are provided with said axial holes 30 for the bolts 29. In the embodiments of the attachment means illustrated in Figures 3 to 8 the groove 24 is defined between the outer circumferential surface of the end wall and a separate outer ring 70 which surrounds the end wall 4, 5. The outer ring 70 has substantially an L-shaped cross-section with an axially extending shank 71 and a radially inwardly extending shank 72. In the embodiment according to Figures 3 and 4 the shank 72 has an axially protruding projection 73 which is arranged to be received in a circular recess 74, corresponding to the projection 73, on the outer side of the end wall 4, 5 in order to fix the position of the outer ring 70 radially to the end wall. The outer ring 70 is screwed to the end wall by means of a plurality of axial bolts 75 extending through axial holes 39 in the shank 72 and screwed into tapped axial holes 76 in the end wall 4, 5. The groove 24 is thus defined by the axial shank 71 and the end wall 4, 5. Most of the inner side wall 26 in radial direction of the groove 24 converging towards its bottom 27 is axial with respect to the axis of rotation 36 of the jacket 3, while a small part of the side wall 26 is bevelled to form a conical guide surface 77 disposed to facilitate insertion of the edge portions 8, 9 of the jacket 3 into the groove 24 when the jacket is being mounted. To facilitate assembly of the outer ring 70 it is suitably divided into a plurality of circular identical arc-segments, e.g. six segments. To facilitate assembly of a jacket 3 on the end walls 4, 5 an aid may be used of the type and in the manner illustrated in Figure 4. The aid consists of a plurality of guide pins 78 which temporarily replace a specific number, e.g. every two bolt, of the bolts 75 normally retaining the outer ring 70 to the end wall 4, 5. The holes selected for the guide pins 78 are drilled through so that a conically tapering guide portion 79 of each guide pin 78 will be located on the inside of the end wall 4, 5. The conical guide surface 77 of the groove 24 cooperates with the conical guide portions 79 of the guide pins 78 so that the edge portion 8, 9 of the jacket can be guided over from the conical guide portions 79 to the guide surface 77 and then into the groove 24 to its bottom 27 or the vicinity thereof. The segments forming the wedge body 28 are then mounted by the bolts 29 so that the jacket is firmly wedged as described above. In the embodiments of the attachment means illustrated in Figures 5 to 8 the radial shank 72 is received in a corresponding recess 80 on the outer circumferential surface of the end wall. The outer ring 70 is screwed to the end wall by means of a plurality of radial bolts 81 extending through radial holes 90 in the shank 72 and screwed into tapped radial holes 82 in the end wall. The groove 24 is defined also in this case by the axial shank 71 and the end wall 4, 5. While the clamping members 32 of the embodiments described above are located on the outer side of the jacket 3 the clamping members 32 according to Figures 5 to 8 are located on the inner side of the jacket 3. In this case the radially outer side wall 26 of the groove 24 is formed axially in order to receive the edge portions of the jacket, and the radially inner side wall 25 is bevelled. In addition to the wedge body 28 previously described the clamping members 32 according to Figures 5 to 8 also include a tension body 83 located axially inside of the wedge body 28 and including a radially outer portion 91 and a radially inner portion 92. The inner portion 92 extends radially inwards from the wedge body 28, and in axial direction it is located at a distance from the end wall in order to admit the wedge body 28 to be pushed into the groove 24. The wedge body 28 is adapted to the shape of the groove 24 in the same way as previously described. In the embodiment according to Figures 5 and 6 the wedge body 28 and tension body 83, seen in a cross section, are formed as an integral piece, whereas in the embodiment according to Figures 7 and 8 said bodies 28, 83 are formed as separate pieces. The surface of the tension body 83 facing the jacket is formed with a conical guide surface 88 intended to facilitate insertion of the edge portion of the jacket 3 into the groove 24 when the jacket is being mounted. The radially inner portion 92 of tension body 83 has axial tapped holes 30 which are aligned with axial through-holes 31 in the end wall for insertion of bolts 29 from the outer side of the end wall and for engagement with the holes 30 of the tension body 83. By means of the bolts 29 the radially inner portion 92 of tension body 83 is pulled in the direction to the end wall 4, 5 so that the radially outer portion 91 of tension body 83 pushes the wedge portion 28 into the groove 24. In order to ensure a uniform distribution of the wedge forces circumferentially the clamping members 32 according to Figures 5 to 8 are provided with a plurality of slots, e.g. 12 slots, extending radially and axially. In the embodiment according to Figures 5 and 6 the wedge body 28 is provided with through-slots 84, and the radially outer portion 91 of the tension body 83 is provided with through-slots 89, which are aligned with the slots 84, whereas in the embodiment according to Figures 7 and 8 only the wedge body 28 is provided with through-slots 84. It is suitable in the first case to dispose a seal 85 between the outer ring 70 and the end wall, whereas in the second case a similar seal(s) 85 may be disposed at the same position and/or between the tension body 83 of the clamping member and a part of the end wall. Said part may consist of a support ring 86 protruding from the inner side of the end wall. When the clamping member 32 is to be loosened in connection with dismantling of the jacket it may be suitable to use a plurality of press screws 87 which are screwed into axial tapped holes in the radial shank 72 of the outer ring, said press screws being aligned with the groove 24 as illustrated in Figures 5 and 6. The press screws 87 are screwed into engagement with the wedge body 28 and urge the wedge body until the wedge engagement is released. Before the press screws 87 are screwed in the axial bolts 29 are first loosened and then the radial bolts 81 so that the clamping member 32 will be free to move when the press screws 87 are screwed in. The outer ring 70 of the embodiments shown in Figures 5 to 8 may consist of a plurality of identical circular arc-segment. The clamping member 32 according to Figure 5 may be formed as a circumferentially unitary ring or may be divided into identical segments with or without said slots. The wedge body 28 according to Figure 7 may consist of a circumferentially unitary ring or a ring divided into identical segments with or without said slots, whereas the tension body 83 consists of a circumferentially unitary ring or a ring divided into identical segments. An advantage to locate the clamping members 32 radially inside the jacket as shown in Figures 5 to 8 is that it is not necessary to remove them when the jacket is to be replaced. A further advantage is that the clamping members 32 have a cylindrical outer surface 26 so that they can be attached to the end walls and easily be machined to necessary roundness and desired outer diameter. Another advantage is that the cross-section of the outer ring 70 is decreased markedly resulting in a markedly decreased weight of each segment so that the handling of the segments is facilitated when the jacket is to be replaced, in particular in connection with rolls having large diameter. Before the bolts 29 are fully tightened it is advisable to place the chamber 14 under a low over-pressure by blowing in air. The jacket 3 will then endeavour to assume a uniform shape circumferentially and should any unevenness exist differences will appear in the axial strains at the edge portions 8, 9 of the jacket. Since axial movement of the edge portions is now permitted those circumferentially sections of the edge portions where the strains are greatest will be pulled out until uniformity has been achieved. Thereafter the bolts 29 are finally tightened to achieve the desired strong wedge joint.

Claims: A press roll (2) cooperable with a counter roll (1) to form a press with a long nip for paper or board machines, said press roll comprising two end walls (4, 5), a tubular, flexible, liquid-impervious jacket (3) secured at its edge portions (8, 9) by means of an attachment means to peripheral portions (6, 7) of the end walls (4, 5); stationary support members (12, 13) for supporting the end walls, said end walls comprising bearing means (35) for permitting rotation of the jacket (3) and the end walls (4, 5) in relation to the stationary support members (12, 13) about an axis of rotation (36); and a press shoe (15) forming together with the counter roll (1) a pressing zone having said long nip, the jacket (3) upon rotation being moved through the pressing zone in sliding contact with the press shoe (15), characterized in that each attachment means for securing an edge portion (8, 9) of the jacket to the end wall (4, 5) comprises a circular clamping member (32), which includes a wedge body (28), and a circular groove (24) disposed on the inside of the end wall (4, 5) to receive the edge portion (8, 9) of the flexible jacket (3) and the wedge body (28), the groove (24) and wedge body (28) being provided with cooperating wedge-forming surfaces (25, 33; 26, 34); and that the clamping member (32) includes means (29) for forcing the wedge body (28) into the groove (24) and retaining it therein in order to clamp the edge portion (8, 9) of the jacket (3) by means of wedge action, against the end wall (4, 5). A press roll as claimed in claim 1, characterized in that the groove (24) converges inwardly towards its bottom (27); and that the side wall (26) of the groove (24) against which the jacket is intended to contact is substantially parallel with the axis of rotation (36) of the jacket. A press roll as claimed in claim 1 or 2, characterized in that the groove (24) is defined by an outer circumferential surface of the end wall (4, 5) and an outer ring (70) which is secured to the end wall by means of a plurality of bolts (75; 81). A press roll as claimed in any of claims 1-3, characterized in that the clamping member (32) is located at the inner side of the jacket (3). A press roll as claimed in any of claims 1-3, characterized in that the clamping member (32) is located at the outer side of the jacket (3). A press roll as claimed in claim 4 or 5 in combination with claim 3, characterized in that the outer ring (70) has a substantially L-shaped cross-section and includes an axially extending shank (71) surrounding the groove (24) and a radially extending shank (72) provided with holes (39; 90) for said bolts (75; 81) for attaching the outer ring (70) onto the end wall (4, 5). A press roll as claimed in claim 6, characterized in that the holes (90) in said radial shank (72) are perpendicular to the axis (36) and are radially aligned with radial tapped holes (82) in the end wall for screwing the bolts (81) therein. A press roll as claimed in claim 6, characterized in that the holes (39) in said radial shank (72) are parallel to the axis (36) and are axially aligned with axial tapped holes (76) in the end wall for screwing the bolts (75) therein. A press roll as claimed in claim 8, characterized in that the radial shank (72) has an axially extending projection (73); and that the end wall (4, 5) has a recess (74) corresponding to the projection (73) to receive the projection (73) to fix the position of the outer ring (70) radially in relation to the end wall (4, 5). A press roll as claimed in claim 3 or any of claims 4-9 in combination with claim 3, characterized in that the outer ring (70) is formed by a plurality of identical circular arc-segments. A press roll as claimed in claim 8 or 9, characterized in that a plurality of guide pins (78) are provided to assist in inserting the jacket (3) into the groove (24), said pins (78) being inserted in through-holes (76) in the end wall (4, 5) and each having a free guiding portion (79) located on the inside of the end wall, radially inside and in the vicinity of the groove (24) so that the edge portion (8, 9) of the jacket can be guided into the groove (24) from the free guide portions (79). A press roll as claimed in claim 11, characterized in that the guiding portion (79) is conical in shape and arranged to cooperate with a conical guide surface (77) of the groove (24) to allow sliding transfer of the edge portion (8, 9) of the jacket. A press roll as claimed in any of claims 1-12, characterized in that the clamping member (32) is provided with axial tapped holes (30) disposed to be aligned with axial through-holes (31) in the end wall (4, 5) or the outer ring (70) thereof; and that said means for forcing the wedge body into the groove (24) and retaining it therein include a corresponding number of bolts (29) for screwing into the clamping member (32). A press roll as claimed in claim 13, characterized in that the holes (30) in the clamping member (32) for receiving the bolts (29) are disposed in the wedge body (28) of the clamping member. A press roll as claimed in claim 13, characterized in that the clamping member (32) includes a tension body (83) located axially inwardly of the wedge body (28) and including a radially outer portion (91) and a radially inner portion (92) extending radially inward from the wedge body (28), said radially inner portion (92) being located at an axial distance from the end wall (4, 5) to permit the wedge body (28) to be pushed into the groove (24); and that the holes (30) of the clamping member (32) for the bolts (29) are disposed in said radially inner portion (92) of tension body (83). A press roll as claimed in claim 15, characterized in that the clamping member (32) includes a guide surface (88) for guiding the jacket (3) into the groove (24) when the jacket is being mounted. A press roll as claimed in claim 15 or 16, characterized in that the wedge body (28) and the tension body (83) form an integral ring. A press roll as claimed in claim 15 or 16, characterized in that the wedge body (28) and the tension body (83) are formed as separate rings. A press roll as claimed in claim 17, characterized in that the clamping member (32) has a plurality of slots (84) extending axially and radially through the wedge body (28). A press roll as claimed in claim 15 or 18, characterized in that the clamping member (32) has a plurality of slots (84) extending axially and radially through the wedge body (28) and a plurality of slots (89) extending axially and radially through the radially outer portion (91) of the tension body (83). A press roll as claimed in claim 20, characterized in that the slots (84) in the wedge body (28) are aligned with the slots (89) in the radially outer portion (91) of the tension body (83). A press roll as claimed in any of claims 6, 15-21, characterized in that a plurality of press screws (87) are axially disposed in the radial shank (72) of the outer ring (70) and aligned with the groove (24), the screws (87) when screwed into the groove (24) and pressing against the wedge body (28) being adapted to release said wedge action. A press roll as claimed in claims 5 and 14, characterized in that the wedge body (28) is formed by a plurality of identical circular arc-segments.

Inventors: ILMARINEN ANTTI ISAKKI, KARLSSON LEIF STEFAN, KARLSSON NILS-ERIK ROLAND, SAEFMAN NILS-ERIK, ZOTTERMAN CARL, ILMARINEN, ANTTI ISAKKI, KARLSSON, LEIF STEFAN, KARLSSON, NILS-ERIK ROLAND, SAEFMAN, NILS-ERIK, ZOTTERMAN, CARL, Säfman, Nils-Erik
Applicants: VALMET PAPER MACHINERY INC, VALMET PAPER MACHINERY INC.
Application year: 1991
Main classification: D21F3
IPC codes: D21F3