ADJUSTMENT GEAR ASSEMBLY

Abstract: The adjustment gear assembly is intended to be mounted in connection with the headbox of a paper machine, the headbox of a paper machine being provided with a plurality of adjustment gears (11) mounted at fixed intervals side by side for adjusting the size of a slice (7). Said adjustment gears (11) are connected with a profile bar (13) adapted to be movable relative to a headbox body (1, 2) by means of said adjustment gears (11). In addition, at least two of the adjustment gears (11) is fitted in a housing (10) or the like which is removably fastened to the headbox body (1, 2).

Description: Adjustment gear assembly The present invention relates to an adjustment gear assembly intended to be mounted in connection with the headbox of a paper machine, the headbox of a paper machine being provided with a plurality of adjustment gears mounted at fixed intervals side by side for adjusting the slice profile, said adjustment gears being connected with a profile bar adapted to be movable relative to the headbox body. This type of adjustment gear assembly is known e.g. from US Patent 3 413 192. In this solution, however, each adjustment gear is individually connected between a profile bar and a horizontal main beam. The cited solution is disadvantageous especially in terms of installation, basic adjustments and repair work. An object of this invention is to introduce an adjustment .gear assembly for providing a reliable adjustment gear assembly to be mounted in connection with the headbox of a paper machine. The adjustment gear assembly is primarily characterized in that at least two of the adjustment gears are fitted in a single housing or the like which is removably fastened to the headbox body. At least in some applications it is possible to fit all adjustment gears in connection with the headbox in at least a single housing. Furthermore, the adjustment gear assembly may include two or more housings which are all provided with at least two adjustment gears. A major advantage gained by the present solution is that an assembly, contained in a housing or a like and comprising at least two adjustment gears, can be preset at a manufacturing plant to form a unit which is ready to be mounted in connection with a headbox without exacting installation work. A housing or the like can be readily replaced even during a short down time of a paper machine. Some preferred embodiments of an adjustment gear assembly of the invention will now be described in more detail with reference made to the accompanying drawings. In the drawings fig. is a schematic perspective view of the headbox of a paper machine, fig. 2 is a sectional view of the detail A in fig. 1, figs. 3-5 illustrate from different directions the structure of an adjustment gear assembly of the invention in an embodiment comprising two parallel adjustment gears and figs. 6-8 also illustrate from different directions the housing structure of an adjustment gear assembly in an embodiment comprising eight parallel adjustment gears. Referring to fig. 1, a headbox, provided with an adjustment gear assembly of the invention, comprises a stationary body portion 1 and a body portion 2 movable relative to said stationary body portion 1. In order to displace the movable body portion, a coarse adjustment mechanism 3 is fitted between body portions 1 and 2. The headbox further includes a set of pipes 4 for supplying stock into a slice 7. The headbox is further provided with a roll 5 around which runs an endless wire 6, which is shown with dash-and-dot lines and upon which is distributed the stock issuing from slice 7. The movable body portion 2 comprises a substantially horizontal main beam 8 with its brackets for securing said body portion 2 to coarse adjustment mechanism 3. Furthermore, in the embodiment shown in fig. 1, the movable body portion 2 is provided with three parallel housings 10 of the invention, each fitted with four adjustment gears 11. Each housing 10 is secured e.g. with a bolt attachment 15 to the horizontal main beam 8. The adjustment gears 11 are linked e.g. through the intermediary of pull rods 12 to a profile bar 13 used for the fine adjustment of slice 7. Fig. 2 particularly illustrates a joint between the bottom 10a of housing 10 and the main beam 8 as well as a joint between the stem 14 of adjustment gear 11 and the pull rod 12. The main beam 8 is provided with a flat 8a which has a hole 8b therein for connecting a stem 14 extending from the bottom 10a of housing 10 with said pull rod 12. Figs. 3-5 illustrate the first embodiment of a housing 10 for an adjustment gear assembly of the invention. This embodiment comprises two parallel adjustment gears 11a, lib fitted inside a housing 10. The housing 10 includes a bottom 10a which is further provided with housing 10 fastening means, such as fastening holes 15a for a bolt attachment. The bottom is further provided with a penetration hole 16 for the stem 14 of a particular adjustment gear 11a, lib. The bottom 10a is also provided with a space 17 for accommodating means 18 for preventing the rotation of stem 14. Such constructions used for preventing the rotation of a stem are known as such and, thus, will not be described further in this context. The housing 10 further includes side walls 10b which surround the actual worm gears in vertical direction. The housing includes also a lid 10c provided with a penetration hole 19 for the stem 21 of a dial gauge 20 or the like. The dial gauges 20 of adjustment gears as well as the electronics 20a of measuring sensors are installed inside a protective hood 22, the bottom of said protective hood 22 being provided by the lid 10c of housing 10. The forward section of the housing is provided with control means (figs. 4 and 5), such as hand wheels 23, for adjustment gears 11a, lib and the rear section of the housing is correspondingly provided with drive motors 24 for adjustment gears, which motors can be either stepping or synchronous motors. Also these motors and the electronics, possibly associated therewith, are provided with their own protective hood 25, one wall of said hood being formed by the rear section 10b' of the side walls 10b of housing 10. The protective hoods 22 and 25 are provided with outlets 26, 27 for electric wiring. Particularly figs. 3 and 4 illustrate one special feature of an assembly of the invention. Namely, one essential feature for contributing to the accuracy of slice adjustment is the distance between adjustment gears. The smaller the distance between adjustment gears in the direction perpendicular to the longitudinal direction of stems 14, the more accurate adjustment can be effected. In order to achieve this object the spiral shafts 28, 29, whose opposite ends are provided with hand wheel 23 on the one hand and with the shaft of motor 24 on the other, are mounted between adjustment gears 11a and lib. Thus, the helixes or spirals of spiral shafts 28 and 29 as well as those of spiral wheels 30 and 31 are oppositely directed. Hence, the rotation of these spiral shafts in the same direction produces the movement of stems 14a, 14b in the same direction. The spiral shafts 28, 29 and thus the hand wheels 23 and motors 24 are mounted substantially on top of each other. The spiral wheels 30 and 31 are formed in sleeve-shaped elements 32, 33 provided on the inside with two ball nuts (ball nuts 34 in adjustment gear 11a and respectively 35 in adjustment gear lib) which effect on ball screws 36 connected with stems 14a, 14b. The sleeve-shaped elements 32, 33 are journalled with bearings 37 to the upper surface of the bottom 10a of housing 10 on the one hand and to the lower surface of the housing lid 10c on the other. The housing lid 10c may include a separate axle-box cover 38. Figs. 6-8 illustrate an embodiment of an adjustment gear assembly of the invention, wherein a housing includes eight adjustment gears 11. In this embodiment, especially the pair of adjustment gears furthest to the right in fig. 6 is arranged in a manner that their spiral shafts 28 and 29 are fitted between said adjustment gears. Especially in fig. 6, it can be seen how two adjacent housings 10 can be mounted side by side, whereby the adjustment gear furthest on the right in the left-hand side housing and the adjustment gear furthest on the left in the right-hand side housing can be mounted in the direction perpendicular to the longitudinal direction of the stems in a manner that said gap matches the corresponding distance between the adjacent adjustment gears included in a housing. Referring further to fig. 1, it can be observed from the positions, of control wheels 23 that each housing 10, which includes four adjustment gears, comprises two pairs of adjustment gears provided with oppositely directed threads or spirals as described in connection with fig. 2.

Claims: Claims : 1. An adjustment gear assembly intended to be mounted in connection with the headbox of a paper machine, the headbox of a paper machine being provided with a plurality of adjustment gears (10) mounted at fixed intervals side by side for adjusting the profile of a slice (7) , said adjustment gears (10) being connected with a profile bar (13) adapted to be movable relative to a headbox body (1, 2), c h a r a c t e r i z e d in that at least two of the adjustment gears (11) are fitted in a single housing (10) or the like which is removably secured to said headbox body (1, 2). 2. An adjustment gear assembly as set forth in claim 1, c h a r a c t e r i z e d in that all adjustment gears (11) connected with a headbox are fitted in a single housing (10) or the like. 3. An adjustment gear assembly as set forth in claim 1, c h a r a c t e r i z e d in that the adjustment gear assembly comprises a plurality of housings (10) or the like, which all include at least two adjustment gears (11). 4. An adjustment gear assembly as set forth in claims 1-3, c h a r a c t e r i z e d in that the attachment of housings (10) or the like is effected to a horizontal main beam (8) of the headbox body. 5. An adjustment gear assembly as set forth in claim 1, c h a r a c t e r i z e d in that the housing (10) or the like comprises: - a bottom (10a) which further includes fastening means (15a) for housing (10) or the like and holes (16) for the lead-in of the stem (14) of each adjustment gear (11), side walls (10b) which in vertical direction define the interior of housing (10) and - a lid (10c) for housing (10) or the like provided with a lead-in hole (19) or the like for the stem (21) or the like of a dial gauge (20) or the like. 6. An adjustment gear assembly as set forth at least in claims 1 and 5, c h a r a c t e r i z e d in that the bottom (10a) of housing (10) and the inner surfaces of lid (10c) are provided with bearing journals (37) for each adjustment gear. 7. An adjustment gear assembly as set forth at least in claims 1 and 5, c h a r a c t e r i z e d in that the bottom (10a) of housing (10) is provided with means (18) for preventing the rotation of stem (14). 8. An adjustment gear assembly as set forth at least in claims 1 and 5, c h a r a c t e r i z e d in that said housing (10) is covered with a protective hood (22) intended for the protection of a dial gauge (20) or the like and preferably the electronics (20a) of a measuring sensor, the bottom of said hood being formed by the lid (10c) of housing (10) and/or the rear section of housing (10) is provided with a protective hood (25), which is common to drive motors (24) of the adjustment gears and which joins with the rear section (10b " ) of the side walls (10b) of housing (10). 9. An adjustment gear assembly as set forth in claim 1, c h a r a c t e r i z e d in that said housing (10) or the like includes at least one pair of adjustment gears (11a, lib) designed in a manner that their spiral shafts (29, 28) or the like are positioned between said adjustment gears (11a, lib) and that said pair of adjustment gears (11a, lib) is so designed that spiral shafts (28, 29) or the like as well as their associated spiral wheels (30, 31) are opposite to each other in terms of threading direction. 10. An adjustment gear assembly as set forth in claim 9, c h a r a c t e r i z e d in that said spiral shafts (28, 29) or the like along with their drive motors (24) and hand wheels (23) are mounted essentially on top of each other.

Inventors: NIEMENMAA SEPPO, SUNI JUHA, NIEMENMAA, SEPPO, SUNI, JUHA
Applicants: KATSA OY
Application year: 1990
Main classification: D21F1
IPC codes: D21F1