This invention relates to a device for flushing especially endless wires of paper making machines with a cleaning fluid, said device comprising a drive means operative for transmitting rotary motion of a reversible direction, a motion converter arranged to change the rotary motion into a recipro¬ cating, linear one and at least one flushing means ejecting a jet of fluid and having an inlet for cleaning fluid. A wire is a wire cloth of a plastic material, steel or the like in the form of an endless belt used in paper making machines. The wire travels in its longitudinal direction over a number of rolls and is propelled at a rate suitable for the current paper manufacture. A suf- ficient amount of pulp is continuously supplied to the upper part of the wire and the paper web to be formed is travelling in the extension of the upper part of the wire further through the press section of the paper making machine. For the best possible way of function of the wire it must be cleaned by flushing its lower portion preferably from below so that deposits in the form of remaining rests of e.g. pulp are removed from it.

Flushing is usually carried out in that water of a high pressure is supplied to a plurality of flushing nozzles located beneath the lower part of the wire, said nozzles being arranged in a successive row so that they cover the entire width of the wire. In order that clea¬ ning should be as efficient as possible the flushing device is usually so embodied that each flushing nozzle performs a reciprocating linear movement during flushing calculated transversely of the wire. An eccentric mechanism for conversion of the rotary motion of a drive motor into a reciprocating linear motion of the flushing nozzles is then normally used due to which the linear

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motion rate of the flushing nozzles will vary for a motion cycle. The uneven motion rate necessitates flus¬ hing of the wire for long periods of time and with a relatively high pressure of the cleaning fluid before a satisfactory cleaning of the wire is obtained. More¬ over, it has been found to be problematic to accomplish an easy running bearing permitting a reciprocating li¬ near motion of the flushing means. This is primarily due to the fact that the flushing means mostly has a rela- tively great length and that it operates in an extre¬ mely dirty environment.

It is the object of this invention to provide a flushing means for wires and the like not having said shortcomings, and this object is achieved by the device of the invention being provided with the characteri¬ stic features defined in the claims.

Among the many advantages of the flushing device according to the invention the following can be men¬ tioned. 1) The flushing device is so designed that both its drive means and motion converter can be placed at an arbitrary distance from the paper making machine, and in this way they can be simply protected from an aggres¬ sive environment. 2) Both the drive means, motion converter and sup¬ ply pipe for cleaning liquid can be placed on the non- service side of the paper making machine.

3) The interior pipe of the flushing means of the flushing device supporting the flushing nozzles is moun- ted very smooth-running in an outer pipe provided with a slot, which does not require any extra internal wor¬ king due to the special embodiment of the bearing.

4) The bearing of the flushing means operates satis¬ factorily even when the flushing means is strongly soi- led.

5) The inner pipe with the flushing nozzles can be simply dismounted from the flushing decive for cleaning

and service even when the paper making machine is in operation.

6) The motion converter is so designed that the li¬ near motion of the flushing nozzles will be very even and fine which means that each mesh of the wire can be flushed so efficiently that the need of using high pres¬ sures of the cleaning fluid is reduced, at the same time as the operating time of the flushing device can be minimized. 7) Almost all so-called "dead travel" due to play has been eliminated as the flushing device only shows a few number of movable parts.

8) The powerconsu ption of the flushing device is very low. 9) Low manufacturing costs. 10) Reliable function. Illustrative examples of the invention will be described more in detail below with reference to the enclosed drawings, in which Fig.1 is a lateral view, partly in section, showing a flushing device according to the invention exclusive of the very drive means, Fig.2 is a lateral view and, on a larger scale, a longitudinal section of the motion converter of the flushing device, Fig.3 is a lateral view of the flushing means of the flushing device, partly in section, and Fig. 4 is a section along the line IV-IV in Fig. 3.

A flushing device according to the invention com¬ prises three connected units in the form of a drive means (not shown) , a motion converter 1 and a flushing means 2.

The drive means comprises a reversible electric motor which is connected, optionally via a gear, to a half 4 of a coupling 3 of the motion converter 1 (see Fig 2) . The other half 5 of the coupling 3 is connected to a motion screw in the form of a ball screw 6. The ball screw 6 mounted in a bearing unit 7 supports an associated nut 8. The free end 9 of the ball screw 6

projects into a hollow shaft 10, to which the nut 8 is connected. The shaft 10 is externally axially displace- ably mounted via a ball bushing 20 relative to a surro¬ unding housing 21. When the ball screw 6 is rotated by the aid of the drive means the nut 8 and thus also the shaft 10 will move axially in the longitudinal direction of the ball screw 6. By rotating the ball screw 6 by the aid of the drive means alternately in different di¬ rections a linear reciprocating axial motion of the shaft 10 is accomplished. The stroke length of the linear motion is decided by the distance between two contact-free transducers 11, 12, which are arranged to actuate the direction of rotation of the drive means. The transducers 11, 12, are actuated by a pin 13 projecting from the shaft 10 and running in a longi¬ tudinal groove 14 in the housing 21, and in this way the shaft 10 is simultaneously prevented from rotation.

The flushing means 2 comprises an interior pipe 30 which is provided with a plurality of flushing nozzles 31. Further, the flushing means 2 comprises an outer pipe 32 surrounding the interior pipe 30. A number of bearing means 33 are arranged on the outside of the interior pipe 30, which enable an axial displacement of the interior pipe 30 in the outer pipe 32. The out- er pipe 32 is provided with a longitudinal groove 34 so that jets of cleaning fluid from the flushing nozzles 31 may pass by the outer pipe 32. Thus, the outer pipe 32 should be adapted e.g. to the founda¬ tion of a paper making machine at a suitable distance from the object to be flushed, e.g. a wire. Adaptation is carried out so that the groove 34 faces the object to be flushed, i.e. so that the jets of cleaning fluid from the flushing nozzles 31 hit the current object. f ^Λ r flushing. Inside of the outer pipe 32 diametrically opposed to the groove 34 a guide means in the form of a pipe 43 is arranged, the object of which is to orient the interior pipe 30 in respect of turning relative to

the outer pipe 32 so that the jet nozzles 31 of the in¬ terior pipe 30 will always be straight in front of the groove 34.

Each bearing means 33 is slidingly mounted relative to two rods 37, 38 passing through. The ends of the rods 37, 38 are connected to two flanges 39, 40 arranged in spaced relationship to each other, and, in their turn, connected to the interior pipe 30. The bearing means 33 is preferably manufactured from some suitable plastic material and shows openings 35, 36 adapted to the outer contours of the rods 37, 38. Moreover, the bearing means 33 has a clearance recess for the interior pipe 30 and its outer contour is made to abut parts of the inner surface of the outer pipe 32. All bearing means 33 and flanges 39, 40 have recesses 44 and 45, respectively, corresponding to the pipe 43. It should also be mentio¬ ned that it may be suitable to arrange the rods 37, 38 so that they are detachable from the flanges 39, 40, which enables a simple replacement of worn down or damaged bearing means 33.

The interior pipe 30 with the slidingly arranged bearing means 33 has a detachable end plug 50 at its end facing away from the motion converter 1 , said plug sealing this end of the interior pipe 30. At its end facing the motion converter 1 the interior pipe 30 is detachably connected via a pipe coupling 51 to a sup¬ ply pipe 52 for cleaning fluid, for example in the form of high pressure water.

On opposite sides of the supply pipe 52 two flat rods 53 are welded which are articulatedly connected at their free ends to one end of a rod 54. The rod 54 is at tts other end articulatedly connected to a link¬ age means 55 adapted to the shaft 10 of the motion con¬ verter 1. If it is desired to protect the drive means and the motion converter 1 from the aggressive environ¬ ment to which the very flushing means is mostly exposed this can simply be done by making the rod 54 enough long.

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This has the effect that almost only the parts of the flushing means 2 need be made from an expensive mate¬ rial, for example stainless steel, which stands the above-mentioned aggressive environment, whereas the other parts of the flushing device may be made from materials only standing more normal environments.

In order that the entire wire might be satisfactori¬ ly flushed the distance between adjacent flushing nozz¬ les 31 must of course not exceed the stroke length of the motion converter 1.

By providing the drive means with speed control you can, if desired, adapt the linear motion velocity of the motion converter 1 to the current velocity of the wire and, consequently, optimize the cleaning process. It should be realized that the flushing means of the invention of course is useful for many other objects besides flushing of said wires.

The invention is not restricted to what is shown and described, but changes and modifications thereof are possible within the scope of the appended claims.