The present invention relates to a tubular spray oscillator which is intended in particular for washing the wires of paper machines with cleansing liquid, and which includes fastener means by means of which the oscillator can be attached to one side of one end of a tubular spray, and wherein drive means are provided for rotating the oscillator in alternate direc¬ tions, and wherein a movement converter is provided for translating rotary movement to reciprocatory, linear movement.

A wire is a screening cloth which may be made of plastic material, steel or some other convenient material and which is in the form of an endless belt used in paper machines. The wire runs over a number of rollers in its longitudinal direction and is driven at a speed appropriate to the paper manufacturing process in question. A suitable quantity of paper pulp is delivered continuously to the upper run of the machine wire and the ultimate paper web runs in the extension of the upper run of the wire and through the press section of the machine. In order for the wire to function in the best possible manner, it is necessary to clean the wire by washing the lower part or rear of the wire, suitably from beneath, so as to remove any paper pulp residues that may have stuck to the wire.

The wire is normally flushed clean by applying water at high pressure through a plurality of spray nozzles located beneath the bottom run of the wire, these nozzles being disposed sequentially in line so as to cover the full width of the wire. To ensure that the wire is cleaned as effectively as possible, each rinsing nozzle is normally arranged to move reciprocatingly in the transverse direction of the wire during a wire-cleaning operation.

One problem with this arrangement, however, is that the nozzles of the tubular sprays tend to become blocked when the

cleaning liquid, normally water, is contaminated with solid particles. Furthermore, the nozzles become worn and need to be replaced at regular intervals. It is therefore necessary to dismantle the tubular spray regularly for inspection and like purposes. Dismantling of the spray tube is made diffi¬ cult, however, by virtue of the unfavourable positions of the oscillators of known wire-cleansing equipment when seen from a dismantling aspect. The oscillator is sometimes positioned in the extension of the longitudinal axis of the tubular spray, for instance. Removal of the oscillators is therefore complicated and time-consuming. It has also been found problematic to provide a drive means which can be easily fitted in the space available around a paper machine, this space often being relatively confined, without it being necessary to prepare a suitable space or to move some other piece of equipment. This problem is particularly manifest when wishing to provide an existing tubular spray with a new oscillator, which also requires the provision of a separate base for the tubular spray drive unit adjacent the paper machine.

It has also been necessary to arrange two or more tubular sprays adjacent one another in order to clean satisfactorily those parts of the path travelled by the wire that have a tendency to collect and retain particularly large quantities of paper pulp.

Accordingly, the object of the present invention is to provide a simplified and inexpensive means for driving the tubular spray which, as a result of its structural design, can be fitted readily to an existing tubular spray, and which greatly simplifies the task of dismantling a tubular spray for repeated inspection and examination. A further object of the invention is to provide an oscillator whose construction will allow the position of the oscillator to be readily adjusted by rotating the oscillator around the tubular spray, and which will also allow the position of the oscillator to be adjusted

by moving the oscillator along the outer tube of the tubular spray. Still another object of the invention is to provide an oscillator which will greatly facilitate replacement of the water delivery hose while the oscillator is in operation. Yet another object is to provide an oscillator which can be allowed to drive two or more mutually adjacent tubular sprays in addition to driving a jet delivery inner tube of a tubular spray.

These objects are achieved with an arrangement having the characteristic features set forth in the following Claims.

The invention will now be described in more detail with reference to an exemplifying embodiment thereof and also with reference to the accompanying drawing, in which

Fig. 1 is a partially cut-away side view of a washing arrange¬ ment which includes an oscillator in accordance with the invention; Fig. 2 is a sectional side view in larger scale of the inventive oscillator; and

Fig. 3 is a front view of the power transmission device of the inventive oscillator.

Fig. 1 illustrates an inventive oscillator 1 which is mounted beneath a machine wire 26 and which includes attachment devices 2 by means of which the oscillator can be mounted parallel with the longitudinal axis and in a selective position at one end of a stationary outer tube 10 of a tubular spray 3. The arrangement also includes a drive means 4 and a movement converter 5 which functions to impart linear recipro¬ catory, axial movement to a jet delivering inner tube 6 of the tubular spray 3, an electrical connecting device 7, and a power transmission means 8 in the form of a dogging means which functions to transfer the axial movement from the movement converter 5 to the inner tube 6.

The inner tube 6 is provided with a plurality of washing or

rinsing nozzles 9, and the outer tube 10, which surrounds the inner tube, is provided with an upwardly facing and longitudi¬ nally extending groove (not shown in the Figure) so that the jets of washing liquid exiting from the nozzles 9 are able to pass freely through the groove and therewith the outer tube 10. Mounted on the outer surface of the inner tube 6 are a number of bearing means 11 (of which only one is shown in the Figure) which permit the inner tube to be moved axially in the outer tube 10. The outer tube 10 is also provided with attachment devices 12 which are intended for fixed attachment to the base (not shown) of a paper machine. The outer tube 10 is mounted on the base of the paper machine at a suitable distance from the object to be washed, for instance a machine wire. The outer tube is fitted so that the groove will face towards the object to be cleaned, i.e. so that the jets of washing liquid exiting from the nozzles 9 will impinge on the object concerned, i.e. the wire.

The drive means 4 includes a reversible electric motor which is mounted on one side of a mounting plate 23 (see Fig. 2) and connected to gearing in the form of a gear transmission 13 which includes a gear wheel 14 fixedly mounted on one end 24 of a shaft which extends through the mounting plate 23 from the movement converter 5 mounted on the other side of the mounting plate 23. The aforesaid shaft end 24 forms the input shaft of the end of a screw drive in the form of a ball-screw 15 and associated nut 16. The ball-screw 15 is accommodated in a hollow shaft 25 to which the nut 16 is connected. The shaft 25 is journalled in a bushing 17 for axial movement in relation to a surrounding housing 21. When the ball-screw 15 is caused to rotate by the drive means 4, the nut 16, and thus also the shaft 25, will move axially in the longitudinal direction of the ball screw 15. The shaft 25 can be caused to move reciprocatingly, by causing the drive means 4 to rotate the ball screw 15 alternately in different directions. The length of linear movement is determined by the distance between two adjustable limit sensors 18, 19 mounted in the

gearing and adapted to influence the direction of rotation of the drive means.

An electric switch means 7 for the motor is provided above the movement converter 5 and includes an inspection flap which faces away from the paper machine so as to enable the coupling means to be easily reached for maintenance purposes.

One end of the aforesaid attachment device 2 includes a ring- shaped clamp attachment 20 which embraces the outer tube 10 of the tubular spray and enables the tube to be fixed with the aid of suitable fastener means, for instance screws. The other end 26 of the attachment device 2 is detachably connected to the mounting plate 23 by means of fasteners, such as screws, and includes a circular opening through which the housing 21 of the movement converter 5 extends, therewith enabling the oscillator drive means 4 and/or movement converter 5 to be replaced without needing to make subsequent adjustment to the lengths of stroke of the inner tube 6 of the tubular spray 3. By placing the screws uniformly in a circle outside the circular opening, it is possible to make a peripheral posi¬ tional adjustment by repositioning the drive means 4 stepwise around the centre axis of the movement converter 5. Conse¬ quently, by moving the attachment device 2 it is possible to adjust the position of the drive means 4 stepwise around the centre axis of the movement converter 5 and also to rotate the oscillator drive means 4 and the movement converter 5 continu¬ ously or smoothly around the centre axis of the tubular spray 3. This enables the inventive oscillator to be adapted readily to the space available around the paper machine, this space often being confined.

When the oscillator 1 is attached to the tubular spray 3, the longitudinal axis of the ball screw 15 will be positioned generally parallel with the longitudinal axis of the inner tube 6.

The inner tube 6 extends through a guide 30 which is mounted at one end of the tubular spray 3 and which serves as a slide bearing for a coupling means 22 to which a water hose 23 is also connected. The force transmission means 8 extends perpendicularly from the free end of the shaft 25 of the movement converter 5 to the end of the inner tube 6 to which the coupling means 22 is attached, so as to transmit the linear reciprocatory movement of the shaft 25 to a similar linear reciprocatory movement of the inner tube 6. The force transmission means 8 is pivotally connected to the shaft 25 and is both pivotally connected and longitudinally movably connected to the coupling device 22 in order to take-up those movements which occur as the inner tube 6 moves backwards and forwards in the tubular spray 3, and therewith movements within the angular deflection range of the inner tube 6. The force transmission means 8 has an upper end-part 31 in which a hole is provided and which is connected to the free end of the shaft 25. The force transmission means also includes a lower end-part 32 which is provided with an elongated hole having an opening 36 for receiving the coupling device 22. The coupling device 22 includes a nipple tube 33 which is connect¬ ed to the hose 23 and also to a known type of quick-coupling 34 connected to the inner tube 6. The nipple tube 33 also includes two permanent collars 35, e.g. welded collars, between which the power transmission means is attached to the nipple tube 33, by threading the opening 36 over the tube 33 and hooking the transmission means firmly thereto.

As a result of this construction, the force transmission means 8 will consistently take-up radial variations in the distance between the movement converter 5 of the oscillator and the inner tube 6 as a result of those movements that occur as the inner tube 6 moves in the tubular spray 3 and therewith the angular deflection range of the tube, the only forces that are applied to the ball screw 15 being the axially acting forces. The useful life of the ball-screw would be greatly shortened if the ball-screw 15 were to be subjected to forces other than

purely axially acting forces, such as bending forces, for instance.

One valuable attribute in this regard is that an oscillator 1 which is mounted on a tubular spray 3 for driving the inner tube 6 of said spray can also be used to drive additional washing jet delivery tubes of mutually adjacent tubular sprays 3, by providing the reciprocatingly movable shaft 25 of the oscillator with one or more additional force transmission means 8 for transmitting axial reciprocatory movement thereto, or to mutually connect the coupling devices 22 of two adjacent tubular sprays 3, of which only one is driven.

The possibility of adjusting the rotational speed of the drive means 4 enables, if desired, the linear speed of movement of the movement converter to be adapted to the speed at which the wire travels at that particular time, and therewith optimize the wire-cleaning process. It will be apparent to one skilled in this art that the aforedescribed drive means 4 and movement converter 5 can be replaced with a piston-cylinder device in order to achieve the axial reciprocatory movement and that the speed of such an arrangement can be adjusted with the aid of means known to the skilled person.

The illustrated and described embodiments do not limit the scope of the invention, since modifications and changes can be made within the scope of the following Claims.