ARRANGEMENT FOR A SCRAPER BLADE HOLDER

Abstract: Arrangement for a holder (2) intended for a strip-shaped moving scraper blade (4), which holder consists of a slot-shaped blade-accommodating space (5) extending along the envelope surface (3A) of a Yankee cylinder, next to which are arranged strip runners (6) or other supporting devices to support the scraper blade in question, which is capable of moving along the scraper strip blade holder, together with retaining elements capable of interacting with a blade (4) of the kind in question arranged to either side of the blade-accommodating space, viewed in a direction towards and away from said Yankee cylinder (3). The blade (4) is so arranged as to be supported by resilient holding elements (10) acting in a lateral sense relative to the Yankee cylinder. It is possible in this way to achieve effective contact of the blade (4) against the Yankee cylinder (3) in question, irrespective of its form or eventual movements.

Description: Arrangement for a scraper blade holder The present invention relates to an arrangement for a holder intended for a strip-shaped moving scraper blade, which holder consists of a slot—shaped blade—accommodating space extending along the envelope surface of a Yankee cylinder, next to which are arranged strip runners or other supporting devices to support the aforementioned scraper blade, which is capable of moving along the scraper strip blade holder, together with retaining elements capable of interacting with a blade of the kind in question arranged to either side of the blade—accommodating space, viewed in a direction towards and away from said Yankee cylinder. Scrapers of the kind previously disclosed in SE, A, 174048 consist of resilient devices in the form of inflatable rubber tubes or elastic foam rubber strips, between which the blade is accommodated in such a way as to be capable of moving in a resilient fashion. The intention is that the blade shall, by inflation of at least one of the rubber tubes, be forced by its leading edge against an adjacent roller with an adjustable, evenly distributed pressure along the leading edge of the blade. In the previously disclosed design referred to here, the question does not arise at all of a resilient carrier element which carries retaining elements capable of interacting with a blade. The principal object of the present invention is, in the first instance, to make available an arrangement of the kind indicated above which permits, amongst other things, effective contact of the scraper blade against a Yankee cylinder of the kind in question. Said object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially in that the blade is so arranged as to be supported by strips carrying retaining elements for the blade, or similar carrier elements, acting laterally in a resilient fashion relative to the Yankee cylinder. The invention is described below as a preferred illustrative embodiment of a holder arrangement, in conjunction with which reference is made to the drawings, in which: Fig. 1 shows a section through a holder arrangement which accommodates a scraper blade whilst it is in contact with a rotatable Yankee cylinder; Fig. 2 shows a part of the holder arrangement viewed from the side in the direction of the Yankee cylinder; Fig. 3 illustrates the principle of a scraper blade; and Fig. 4 shows in diagrammatic form the application of a scraper blade holder to a Yankee cylinder, viewed from above. In accordance with the present invention retaining elements for a strip—shaped moving scraper blade are carried by a resilient strip or some other similar resilient carrier element, so that the blade can effectively be supported in a resilient fashion laterally relative to a Yankee cylinder, in a direction away from and towards the cylinder. Because the strip, etc., is resilient, it can effectively be permitted to spring out of the way laterally, for example in the event of any unevenness occurring on the cylinder or on a web with which the blade interacts and by which it is influenced. The retaining elements, which may be several in number, need not accordingly be resilient in a direction towards the cylinders in themselves, and it is now sufficient to cause these to be carried by a resilient strip or some similar resilient carrier element, which is important, due amongst other things to the difficult operating conditions under which such retaining elements are required to work. Arranged in such a way as to be capable of being accommodated in a frame 1 of a holder 2 is a strip—shaped scraper blade 4 in a slot—shaped blade—accommodating space 5 extending along a Yankee cylinder of the kind in question and capable of being caused to move along the envelope surface 3A of a so-called Yankee cylinder. Present in said blade—accommodating space 5 are strip runners 6 or other suitable supporting devices, which are arranged for the purpose of supporting moving scraper blades 4 of the kind in question along the scraper blade holder 2 whilst they are in contact with the Yankee cylinder 3. To either side of the blade—accommodating space 5, viewed in a direction towards 7 and away from 8 said Yankee cylinder 3, are arranged retaining elements 9 and 10, which are so arranged as to be capable of interacting with lateral surfaces 4A, 4C of a scraper blade 4 of the kind in question in order to support same laterally. Said retaining elements 9, 10 can be constituted by roller elements and/or by slide elements, and in the illustrated example the retaining elements situated nearest the cylinder 3 are constituted by slide elements 9, whereas those retaining elements which are situated furthest from the cylinder 3 are constituted by rollers 10. The retaining elements 10 are carried by a strip 11 or some similar resilient carrier element which is resilient in a lateral sense relative to the Yankee cylinder 3, so that the blade 4 can be supported in a resilient fashion in a direction away from 8 and towards 7 the cylinder 3 when the blade 4, as shown in Figs. 1 and 3, is in contact with the envelope surface 3A of the cylinder during the removal from the cylinder 3 by scraping of, for example, a paper web 12 running around the cylinder 3 during creping of the web 12 in conjunction with the simultaneous deflection of the web 12 from the cylinder 3 in the direction of the arrow 13. The resilient strip, etc., 11, which preferably extends for the entire length of the cylinder, can be adjustable in a lateral sense relative to the Yankee cylinder 3, for example by the strip 11 being capable at its upper end 11A of being attached to a strip connection part 15 by means of, for example, a matching slot 14 in which said end 11A is held motionless. Said strip connection part 15 is capable of being locked in a desired adjusted position in relation to the holder frame 1, for example by means of set screws 16 and nuts 17 or other suitable securing devices arranged in a row. The strip connection part 15 may, as mentioned above, comprise an upper part 15A, which is capable of gripping around the upper part 11A of the resilient strip, etc., 11, for example by means of the slot 14, and which rests on a supporting part S, for example two strips situated at a certain distance from one another, between which the heads 16A of the screws are accommodated. The set screws 16 are so arranged as to be accommodated by holes 18 which extend through a lower part 15B projecting downwards at an angle from said upper part 15A of the strip connection part. In a locked position effected by means of set screws 16 and nuts 17, the strip connection part 15 is locked so that it is prevented from moving in a direction 8 away from the Yankee cylinder 3, but is preferably permitted to move in a direction 7 towards same. The resilient strip 11 is also so arranged as to be accommodated by its lower part 11B in a slot 19 extending along the blade—accommodating space 5, which slot, like the slot 14, can exhibit slot walls which converge towards the bottom of the slot. The retaining rollers, etc., 10, which are carried by said strip, etc., 11, so that their support axis 10A extends essentially parallel with the blade 4, are so arranged as to make contact during rolling with their respective rolling surfaces 10B against the lateral surface 4A of the blade 4 which faces in a direction 8 away from the Yankee cylinder 3. At the bottom the scraper blade 4 is so arranged as to be supported by a bottom supporting strip 22 adjustable in the vertical sense 20, 21, which supporting strip accommodates said rotatably mounted strip runners 6 internally at the bottom 23A of a slot 23, on the envelope surfaces 6A of which runners the lower part 4B of the scraper blade is so arranged as to be supported as the blade is fed along the envelope surface of the Yankee cylinder 3 in at least one of the directions 24 and 25 along said cylinder 3. Said bottom supporting strip 22 is so arranged as to be controlled by rollers 26 or other control devices, preferably arranged in pairs, which run along a number of slots 27 set at an angle, which slots extend at an angle relative to the scraper blade 4 and its intended feed direction 24, 25, as shown in Fig. 2, for example. Spaces 28, 29, formed between the scraper blade 4 and said holder 1 in the blade—accommodating space 5, are so arranged as to be capable of being sealed effectively by means of a number of so-called dust—sealing devices 30, 31 extending for the extent of the blade along the holder 2, which devices preferably consist of resilient material or are attached to the holder 2 in some other way so as to produce an effective seal. The function of the scraper blade holder arrangement described above should have been appreciated from the foregoing and from the details illustrated in the drawings, although briefly it may be stated that, when the scraper blade 4 is driven by driving means (not shown in the drawing) in either direction of driving 24, 25, accommodated in the space 5 in said holder 2, it is supported by the retaining elements 9, 10 situated to either side of the blade 4. The possibility is afforded in this way for the elements 10 to spring in a direction away from 8 and towards 7 the blade 4, so that they are in effective contact with the surface 4A of the blade facing towards said elements 10, irrespective of any irregularities in the cylinder 3 or the web 12 by which the blade 4 may be influenced. The correct position for the elements 10 has been adjusted beforehand by means of the set screws 16. The opposite side 4C of the blade 4 is in contact, on the other hand, with the retaining element 9, whereas the lower part 4B of the blade is supported by the strip runners 6. The correct height adjustment of the blade 4 is set by causing the bottom supporting strip 22 to move along the slot 27 to the correct level, and then to be locked in the desired set height position by means of an appropriate locking device. The fact that the strip, etc., 11, is resilient means that it can be allowed to spring out laterally, and it is appropriate to cause the elements 10 to be carried close to the centre of the strip in order to achieve maximum resilience of the elements 10. The invention is not restricted to the illustrative example described above and illustrated in the drawings, but may be modified within the scope of the Patent Claims without departing from the idea of invention.

Claims: P a t e n t C l a i m s 1. Arrangement for a holder (2) intended for a strip—shaped moving scraper blade ( 4), which holder consists of a slot—shaped blade—accommodating space (5) extending along the envelope surface (3A) of a Yankee sylinder, next to which are arranged strip runners (6) or other supporting devices to support the scraper blade (4) in question, which is capable of moving along the scraper strip blade holder (2), together with retaining elements (9, 10) capable of interacting with a blade (4) of the kind in question arranged to either side of the blade— —accommodating space (5), viewed in a direction towards (7) and away from (8) said Yankee cylinder (3), c h a r a c t er i zed in that the blade (4) is so arranged as to be supported by strips (11) carrying retaining elements (10) for the blade (4), or similar carrier elements, acting laterally (7, 8) in a resilient fashion relative to the Yankee cylinder ( 3). 2. Arrangement according to Patent Claim 1, c h a r— — a c t e r z e d in that rollers and/or slide elements acting as retaining elements (10) are carried by strips, etc., (11) on their side facing the blade (4). 3. Arrangement according to any of the preceding Patent Claims, c h a r a c t e ri zed in that the resilient strip, etc., (11) is adjustable in a lateral sense relative to said Yankee cylinder (3). 4. Arrangement according to Patent Claim 3, c h a r— a c t e r z ed in that the resilient strip, etc., ( 11) is capable of being attached at its upper end (11A) to a strip connection part (15), which is capable of being locked in a desired adjusted position by means of set screws (16) or other connecting devices. 5. Arrangement according to Patent Claim 5, cha r¬ a c t e r i z e d in that the connection part (15) comprises a part (15A) which is capable of gripping around the resilient strip, etc., (11), which part (15A) rests against a supporting part (S) and is so arranged by means of said set screw, etc., (16) as to be locked so as to be prevented from moving in a direction away from (8) the Yankee cylinder, but preferably so as to be permitted to move towards same. •6. Arrangement according to any of the preceding Patent Claims, c h a r a c t e r i zed in that the resilient strip, etc., (11) is so arranged as to be accommodated by its lower part (11B) in a slot (19) extending along the blade—accommodating space (5). 7. Arrangement according to any of the preceding Patent Claims, c h a r a c t e r i z e d in that retaining rollers (10) are carried by the resilient strip, etc., (11) in such a way as to make contact with their rolling surfaces (10B) against the lateral surface (4A) facing away from the Yankee cylinder (3). * 8. Arrangement according to any of the preceding Patent Claims, c h a ra c t e r i ze d in that the scraper blade (4) is so arranged as to be supported by a bottom supporting strip (22) adjustable in a vertical sense and provided with strip . runners, etc., (6). 9. Arrangement according to Patent Claim 8, c h a i— a c t e r i z e d in that the bottom supporting strip (22) is so arranged as to be guided by rollers (26) or other guide devices running along angled slots (27) relative to the scraper blade (4). 10. Arrangement according to any of the preceding Patent Claims, c h a r a c t e r i zed in that dust sealing devices (30, 31) are so arranged as to act between the scraper blade (4) and the holder (2).

Inventors: HEDBERG BOERJE, HEDBERG, BOERJE
Applicants: MEKANPROJEKT MARKNADS AB
Application year: 1988
Main classification: D21G3
IPC codes: D21G3