FI72361B - STOEDARRANGEMANG FOER SPETSLISTEN I INLOPPSLAODAN AV EN PAPPERSMASKIN - Google Patents

Description

72361 1 Paper machine headbox tip strip support

Special measures applicable to certain types of paper 5

The invention relates to a support for a headboard of a paper machine headbox, the tip strip being supported against the outer surface of the front wall of the headbox beam, the support using a support part or a set of support parts fastened to said outer surface the support force is provided at least in part, preferably completely, by said screws or the like.

As is known, the lip opening of the headbox, from which the pulp suspension-15 jet discharges onto the forming wire or forming molding, is fine-tuned to a tip strip to which several parallel adjusting spindles are connected.

With these adjusting spindles, the tip strip is bent so that the thickness profile of the lip jet is suitable, usually as even as possible. In order to be able to adjust the lip-spindle, the tip strip must be supported to move on its abutment-20 surface, usually on the front wall of the headbox top lip beam.

Said top rail support is known to use two different arrangements, the first arrangement applying a plurality of spring-loaded supports which are evenly spaced along the length of the top bar. Em. in the known arrangement, it is possible to use a low and longitudinally rigid tip strip so that the tip strip is inexpensive to manufacture and is made to operate in the desired area between the adjusting spindles. However, the manufacturing tolerances of the supports and the load springs cause unevenness in the frictional forces corresponding to the adjustment movement of the strip and at the same time in the adjustment movements of the different spindles, so that equal adjustment movements of the different spindles are reflected in different lip changes. This drawback makes it difficult to adjust the lip opening and makes automating this adjustment quite difficult.

35 In said second known arrangement, a series of support members are used, which are loaded by a pressurized load hose. For this solution, reference is made to DE-OS 2 942 966 (cf. FI-Pat. No. 803316, 72361 2 1 to J.M. Voith GmbH). With this known method, the frictional force resisting the adjustment is made uniform when viewed in the longitudinal direction of the tip strip. A disadvantage of this arrangement, however, has proved to be an expensive and uneven rigidity of the tip strip, the adjustability of which in the area between the spindles 5 has proved to be somewhat inaccurate. Said disadvantages are mainly due to the fact that said load hose exerts a force directly on the tip strip, which is why the tip strip must have a sufficient height in order to obtain a sufficient load surface area for the load hoses. The use of load hoses is also associated with functional uncertainty 10 and structural complexity.

The object of the present invention is to avoid or at least substantially reduce the disadvantages which have arisen above.

It is a further object of the invention to provide a tip strip support arrangement in which a low and substantially longitudinally rigid tip strip can be used so that the strip is inexpensive to manufacture and operates as intended.

It is a further object of the invention to provide a tip strip support which achieves a uniform distribution of the frictional force (support force) in the longitudinal direction of the tip strip and thereby a more precise tip strip adjustability.

It is also an object of the invention to provide an even simpler and cheaper support arrangement.

The object of the invention is to provide such a support arrangement in which such a flat support is obtained between the tip strip and its support surface so that 30 fibers cannot escape from the mass suspension comparison of the headbox between the inner wall of the tip strip and its support surface.

In order to achieve the above and later objects, the invention is essentially characterized in that said support members use one or more successive disc springs fixed to said projections or the like of said front wall by means of said screws or the like and to be loaded

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3 72361 Ί against the outside of the top strip and that a suitable support force is obtained by tightening said fastening screws with a suitable force and tensioning said plate spring.

An important further advantage of the invention is that the support forces can be applied as low as possible and close to the lower edge of the lip beam, so that the minimum possible support forces are achieved so that the frictional forces resisting the adjustment of the tip strip remain small.

The invention will now be described in detail with reference to an embodiment of the invention shown in the figures of the accompanying drawing, to the details of which the invention is not narrowly limited.

Figure 1 shows in schematic vertical section a first embodiment of a support arrangement 15 according to the invention.

Figure 2 shows a second embodiment of the support arrangement according to the invention in a manner similar to Figure 1.

Figure 3 is a front view of the support arrangement of Figure 1 or 2.

Figure 4 shows, in a manner similar to Figure 3, another alternative support arrangement according to Figure 1 or 2.

25

The lip portion of the headbox of the paper machine shown in Figures 1-4 comprises a lower lip beam 10 and an upper lip beam 12. Between the lower lip beam 10 and the lower lip wall 12a 12 Attached to the outer surface of the front wall 12b of the upper lip beam 12 according to the invention is a tip strip 15 which is bent by adjusting spindles 13 to control the height and profile of the headbox lip opening.

72361 ί 1 The tip strip 15 has evenly spaced cantilever portions 15b, from which the grooves 15a delimit below, the cantilever portions 15b of the tip strip 15 communicate with the grooves 13a of the lower parts of the adjusting spindles 13. The grooves 13a of the adjusting spindles 13 in the protruding portions 15b of the tip strip 15 are fastened to each other by screws 17. Since the tip strip 15 presses the pressure 5 of the pulp suspension flow F away from the support 5 surface, the tip strip 15 must be supported along its entire length. This support of the top list 15 is arranged to take place by the new arrangement described below.

According to Fig. 1, the support arrangement of the invention is implemented by a planar plate spring 16, which is fastened at its upper part by screws 19 to protruding parts IA fixed to the front wall 12b, which have a sloping front side 1a. Said front side 14a is at a suitably small angle α of a few degrees, e.g. about 5 °, with respect to the main plane of the disc spring 16. According to Figures 1 and 3, under the bases 19a of the fastening screws 19 there is a solid washer 20, which in Figure 4 has been replaced by parts 20, 202. with an assembled washer, the parts of which are tightly terminated at 20 '. As shown in Fig. 3, the disc spring 16 may be a uniform disc spring extending the entire length of the tip strip 15 or a series of disc springs-20 consisting of parts 16, 162-16 M (M pieces), the parts of which are tightly terminated at 16 '. According to Figure 2, the planar disc spring has been replaced by a gentle V-shaped disc spring 16 with a longitudinal fold 16s in the middle and a rounding portion 16R at the tip.

The aid scheme described above works as follows. The screws 19 tension the lower end 16a of the disc spring 16 against the outer side of the tip strip 15 at or just above the front edge 12d of the lower wall 12a of the upper lip beam 12 so as to form a support surface A extending over the entire length of the tip strip 15. The support force in the support surface A is made uniform by tightening the screws 19, for example with a torque wrench 30 or the like, so that there is a suitable small gap V between the outer surface 14a of the cantilever parts 14 and the inner surface of the disc springs 16. Tightening can also be performed by tightening the screws 19 so that said clearance V expires (a = 0 °) and then unscrewing the screws 19 a certain constant amount.

The disc springs 16 support the tip strip 15 like single-arm lever arms with the line of the fulcrum T at the surface 14a and the upper edge of the disc spring 16.

35

As shown in Figures 1 and 2, the cross-sections of the disc spring 16 may vary and a rounding 16R may be used at its lower end 16a, which together with the fold 16s can hold the support surface A at a constant position with respect to the tip strip 15 despite variations in support force.

5

The invention also realizes the important advantage that the support surface A and the support force transmitted through it can be applied as close as possible to the tip of the tip strip 15 in the figures, which means that the support surface A is located just above the lower edge 12d of the wall 12a. This means the possibility of using even smaller support forces, which in turn results in even lower frictional forces resisting the adjustment of the profile of the tip strip 15. The lower the frictional forces that can be adjusted, the more precise the adjustment, taking into account the clearances and deformations of the different parts. In previously known solutions, it has generally been necessary to use substantially higher support forces due to their unfavorable point of action.

When the adjusting spindles 13 are moved in the direction of the arrows B by handwheels known per se at their upper end (not shown), this transfer force 20 is transmitted via the parts 13a, 15b to that point of the tip strip 15 so that the tip strip 15 bends at this point. 16 via support surface A.

According to the invention, there is provided a support arrangement 15 which is advantageous in terms of function and simple in structure and advantageously implemented.

Within the scope of the inventive idea, the various details 30 of the invention may vary, differing only from those exemplified above. The plate springs 16 have holes, grooves or the like for fastening screws 19 or other corresponding fastening parts, e.g. for various quick fasteners known per se.

The following claims set forth within the scope of the inventive idea, the various details of the invention may vary and differ from those set forth above by way of example only.

10 15 20 25 30

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Claims (11)

72361 7 A support for a paper machine headbox tip strip (15), the tip strip (15) being supported against the outer surface of the front wall (12b) of the headbox beam (12), wherein the support uses a support member (16) or support members (16, 162 to 16). ) a set fixed to said outer surface (12b) by screws (19) or the like and wherein the support members (16) have a support surface (A) corresponding to the outside of the tip strip (15) and in which support the tip strip support force is provided at least in part, preferably completely , said screws (19) or the like, characterized in that said support members use one or more successive plate springs (16) fixed by said screws or the like to the projections (14) or the like of said front wall (12b) and the part opposite the mounting of the disc spring (16) or the series of disc springs (16 ^, 162-.16 ^) is adapted to be tensioned against the outer side of the tip strip (15) and that a suitable support force is provided tightening the excitation screws (19) with a suitable force and tensioning said disc spring (16). 1 Claims Support according to claim 1, characterized in that said disc spring (16) or springs are fastened with screws (19) to projections (14) fixed to the front side (12b) of the front wall beam (12) and having a sloping outer side (14a), in connection with which the disc spring (16) or springs are fixed in such a way that in the support position there is a space between said outer side (14a) and the inner side of the disc spring (16), preferably a wedge space (V). 25 Support according to Claim 1 or 2, characterized in that the disc spring (16) or springs are elongate pieces whose longitudinal direction is parallel to the longitudinal direction of the tip strip (15) to be supported. 30 Support according to one of Claims 1 to 3, characterized in that the disc spring (16) is a single unitary spring-like spring which extends over substantially the entire length of the tip strip (15) (Fig. 4). 35 Support according to one of Claims 1 to 3, characterized in that the disc spring (16) consists of a plurality of successive, preferably elongate, disc spring parts (16 .16. 16) which are tightly (16 ') at their ends. I M 8 72361 Support according to one of Claims 1 to 5, characterized in that the main leaf is planar in shape (Fig. 1). Support according to one of Claims 1 to 5, characterized in that the disc spring (16) has a fold (16s) along its length, preferably in its central region. Support according to one of Claims 1 to 7, characterized in that the support point (A) of the disc spring (16) has a rounding (16R), the convex surface 10 of which is tensioned against the outer surface of the tip strip (15). Support according to any one of claims 1 to 8, characterized in that the support point of said disc spring (16) or set of disc springs is arranged in the vicinity of the edge (12d) between the lower wall (12a) and the front wall (12b) of the headbox top lip beam (12), preferably above said edge. Support according to one of Claims 1 to 9, characterized in that a base plate (20) with holes for the screws (19) and which plate (19) is arranged under the bases (19a) of the fastening screws (19) of the disc spring (16) or spring set. 20) is at the outer surface (14a) of the projections (IA) and that said plate is a unitary body extending over the entire length of the disc spring or spring set or a support part consisting of parts (20 ^, 20 ^ · .-). 25 Support according to one of Claims 1 to 10, characterized in that two or more overlapping and tightly opposing plate springs are used for the support. 30 35 9 72361