FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a device for material remov processing of a material layer according to the preamble of appended claim 1. Although the layer may consist of anot material concrete layers are preferably intended here. processing is intended to primarily have the purpose to rem weakened material from the layer. It may be the question removing weakened concrete from concrete layers of walls, bridg and all kinds of other building constructions, whereupon t concrete removed may be replaced by a new one. The high pressu fluid is preferably constituted by water.

Such devices are known per se. As examples of the prior a reference may be made to the Swedish patent publications 451 7 and 461 535. The prior art has the disadvantage that the contr of the movements of the jet tube is defective, so that a more less uneven processing result is obtained on the concrete laye It should here be underlined that it is essential that defecti material is really removed but on the other hand unnecessa material volumes should for economical reasons not be remove since this raise the cost for the subsequent application of n material. The movements of the jet tube are according to t prior art controlled especially in the region of the end pos tions of the carriage but also for the rest so that the regul rity mentioned above concerning the processing occurs.

SUMMARY OF THE INVENTION

The object of the present invention is to show constructive measures for developing a device according to the preamble of claim 1 so that an improved evenness is obtained as far as the material removing processing is concerned over the entire layer surface to be processed.

This object is obtained by the characteristics defined in the characterising part of claim 1.

By means of the solution defined in claim 1 an even processing effect is obtained in the region of the two end positions of the carriage owing to the fact that the jet tube is arranged to be brought into pivoting movement for returning substantially simultaneously as the carriage stops in its end position, wherein the carriage is arranged to be put into movement again, namely in the direction towards its second end position substantially simultaneously as the jet tube terminates its pivoting. The pivoting of the jet tube and the movement of the carriage are carried out with such velocities that the nozzle of the jet tube will move along the longitudinal direction of the guide during substantially the entire turning operation.

The development defined in claim 4 ensure the even processing effect on the material layer by an oscillating movement of the jet tube in such a way that the nozzle will move to and fro in a direction substantially transversal with respect to the guide while a carriage moves therealong.

Further preferred developments of the inventional idea are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a specif description of an embodiment of the invention cited as an exam le.

In the drawings:

Fig 1 is a schematic perspective view of the device according the invention,

Fig 2 and 3 are schematic perspective views illustrating t carriage carrying the jet tube of the device, wherein the mov ment pattern of the jet tube is also illustrated,

Fig 4 and 5 are schematic views of the jet tube, which is illu strated in its two extreme positions and seen perpendicularly t the guide,

Fig 6 is a schematic view of the jet tube seen substantiall parallely to the guide, wherein an oscillating mechanism for th jet tube is indicated, and Fig 7 is a circuit diagram.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The device according to the invention comprises a carrier 1 which here has the character of a vehicle movable on the under layer, for instance a layer of concrete, which is to be process sed. The vehicle is here indicated as being of the track typ with two driving tracks 2. The vehicle is as indicated by th arrows 3 and 4 movable in opposite directions.

On the vehicle 1 there are arranged a longitudinal guide 5 and carriage 6 movable to and fro along this guide and carrying a je tube 7 for directing a high pressure fluid jet towards th underlayer. The guide 5 is intended to in function extend whil making an angle with the directions of movement 3, 4 of th

vehicle and preferably substantially transversally thereto. The guide 5, which may have the character of a girder, is in the example substantially rectilinear. Furthermore, the guide 5 forms a part of a stand 8, which is mounted on the vehicle. The jet tube 7 communicates through a conduit 9 with a source for supply¬ ing a high pressure liquid, in particular water, to the jet tube. This high pressure source is suitably arranged on a separate carriage or the like, although it may also be arranged on the vehicle 1.

As it will be described more in detail below by means of Fig 7, the device comprises driving means 10 for driving the vehicle 1 in the directions 3, 4, a driving means 11 for driving the carriage 6 along the guide 5 and a driving means 12 for pivoting the jet tube 7 about an axis 13 extending substantially trans¬ versely to the guide 5 between extreme positions appearing from Fig 4 and 5. A nozzle 14 of the jet tube is in these extreme positions directed while making an oblique angle with the longi¬ tudinal direction of the guide 5. The jet tube may be arranged to be directed obliquely either in or opposed to the direction of movement of the carriage 6 taking place for the moment. The choice of the inclination direction of the jet tube depends upon the processing result aimed at and the character of the material. The mode of operation in which the nozzle of the jet tube during the movement of the carriage 6 along the guide 5 is always directed in the direction of movement of the carriage indepen¬ dently of in which direction along the guide the carriage is presently moving will be discussed in the continuation of the description below.

It is suitable that the jet tube 7 is arranged to carry out an oscillating movement in the direction of movement 3, 4 of the carrier 1 about an axis 15. This oscillating movement is in other words intended to take place in planes being substantially parallel to the pivot axis 13 of the jet tube 7.

A control unit 16 (Fig 7), for instance a suitable computer,

arranged to control the driving means is arranged to, when t carriage 6 has reached an end position along the guide 5, contr the driving means 12 to pivot the jet tube 7 so that the nozzl thereof during the movement of the carriage in its two direction of movement will be directed in the direction of movement there of. The end positions of the carriage 6 are defined by detectin means 17, which are connected to the control unit 16. As indica ted in Fig 1, an one-armed member 18 is secured on the carriage and intended to cooperate with the detecting means 17.

An attachment 19 for the jet tube 7 is oscillatingly arrange about the axis 15 on a holder 20, which in its turn is turnabl arranged on the carriage 6 about the axis 13. This means that th jet tube 7 will pivot about the axis 13 upon turning the holde 20 thereabout.

Driving means for making the jet tube 7 to pivot about the axi 15 comprise (Fig 2 and 6) a motor 21 and an eccentric 22 drive by means of the motor. This is intended to rotate about an. axi 23 and has an extension 24 being eccentrical with respect to thi axis and acting upon the attachment 19. A lever 25 having a sli 26 engaged by the extension 24 is more in detail rigidly attache to the attachment 19. Thus, the jet tube 7 will upon rotation o the eccentric 22 be put into an oscillating movement indicated b the circular arc a in planes making an angle, preferably substantially right angle, with the longitudinal direction of th guide 5. It is preferred that the oscillating angle a is les than 30° but on the other hand at least 5 ^β and preferably a least 10°. The jet tube 7 extends in the middle of this oscilla ting movement, as seen in the longitudinal direction of the guid 5, substantially in the direct on normal to the layer 27 to b processed.

The motor 21 is arranged on the holder 20 and the eccentric 22 i also mounted on the holder 20 in a bearing. It is preferred tha the axis of rotation 23 of the eccentric 22 is adjustably arran ged on the holder 20, so that the distance of the axis 23 to th

oscillating axis 15 may be varied. The oscillating angle a could by that also be varied.

It is preferred that the driving means 12 for pivoting the holder 20 by the axis 13 with respect to the carriage 6 is constructed as a power means varying its length acting between a point on the carriage 6 and a point on the holder 20 being eccentrical with respect to the axis 13. This power means is suitably a double- acting fluid piston cylinder mechanism (Fig 7).

Although other embodiments are well possible, the driving means 11 for the movement of the carriage 6 along the guide 5 may have the character of a motor, for instance a hydraulic motor, which is arranged on the carriage 6 and drives at least a wheel or gear, which is rotary arranged on the carriage and in a driving engagement with the guide 5.

The control unit 16 (Fig 7) is arranged or adjustable to control the cylinder 12 substantially simultaneously as the carriage 6 is stopped in the first end position defined by one of the detecting means 17 initiate pivoting of the jet tube about the axis 13 with an angular velocity which leads to a velocity of the nozzle 14 along the guide 5 being substantially equal to the velocity of the carriage 6 along the guide, said control unit being arranged or adjustable to control the driving motor 11 of the carriage 6 to initiate the movement of the carriage towards the second end position substantially simultaneously as the pivoting of the jet tube 7 by means of the cylinder 12 is terminated. The jet tube 7 will in other words with its nozzle 14 be in a substantially continuous movement with the same speed along the guide 5 during the entire turning sequence in the end positions of the carriage.

The device comprises means 28 and 29 for adjusting the velocity of the carriage 6 and the pivoting velocity of the jet tube 7, respectively. In the embodiment driven by means of compressed fluid, in particular hydraulic fluid, shown in Fig 7, this adjusting means 28, 29 are thought to be constituted by flow

regulating valves in fluid conduits belonging to the motor 11 a the cylinder 12, respectively. The compressed fluid syste according to Fig 7 comprises in a way known per se a pump 30 which through compressed fluid conduits 31 delivers compresse fluid not only to the driving means 11 and 12 but also to th driving means 10 and 21. There are also valves 32 and 33 in th compressed fluid supplying conduits to the driving means 10 an 21, respectively, which by flow regulation enable adjustment o the operating speeds of the driving means 10, 21 constructed a compressed fluid motors. Return conduits for compressed flui from the driving means 10, 11, 12 and 21 may in conventiona manner emerge into a compressed fluid tank 34, from which th pump 30 is supplied with fluid.

There are control means 35-38 for each of the driving means 10

11, 12 and 21 with the task to start, stop and (concerning al driving means except for 21 for the oscillating movement) revers the direction of the function of the driving means. This contro means 35-38 are in the compressed fluid case illustrated flui valves, which by schematically indicated connections to th control unit 16 are subjected to control by the latter-. The spee regulating valves 32, 33 and 28 for the driving means 10, 21 an

11, respectively, may suitably be arranged in the supply conduit to the latters. With respect to the driving means designed as cylinder 12 for the pivoting of the jet tube 7 about the axis 1 it is however suitable to arrange, in each of the conduit extending between a control valve 38 and the two working chamber of the cylinder 12, the earlier mentioned valve 29 regulatin flow and thereby regulating the speed of length variation of th cylinder 12 and a non-return valve opening to the respectiv working chamber of the cylinder 12 parallely to each other, whic means that the flow regulation and thereby the speed regulatio will take place in the one of the conduits between the contro valve 38 and the cylinder 12 for the moment functioning as return conduit.

The control unit 16 comprises a suitably adjustable time delayin

means for delaying the initiation of the movement of the carri¬ age, when the carriage has reached a first end position, towards the second end position with a period of time corresponding to the time required for the pivoting of the jet tube by means of the driving means 12 from its one extreme position to the other.

It appears from above that the control unit 16 is intended to contain a control program, in which the operator may choose the time delay of the time delaying means to be equal to the time required for the pivoting of the jet tube and also equal to the time during which the carriage 6 not moves on reaching an end position.

The control unit 16 is arranged to control the driving means 10 through the control means/valves 35 to move a distance set when the carriage 6 reaches one of its end positions. The velocity of this movement is determined by the control means/valve 32. The control unit 16 contains a clock adjustable by the operator for defining the movement distance aimed at, so that this clock determines the period of time during which the driving means 10 are in function and thereby the distance. Since the driving means 10 have a control means 35 each, the operator may if required adjust the direction of the vehicle 1 by instantaneously only set one of the driving means 10 into function.

It appears from Fig 4 and 5 that the jet tube 7, as seen paral¬ lely to the pivot axis 13 thereof, is able to pivot angles b in opposite directions from a central position, in which a jet tube is directed as a normal to the surface to be processed. The angle b is preferably maximally 30°, which means that the pivoting movement of the jet tube totally comprises maximally 60 ^* .

The device described functions in the following way: The operato determines in dependence on the actual operating conditions b means of the adjustment means 32 the velocity of the movement o the vehicle 1. The resulting transport distance may be determine by setting the time for the duration of this movement in th

control unit 16. The operator determines by means of the adjust ment means 33 the oscillating speed of the jet tube 7. Further more, the operator determines by means of the adjustment means 2 the velocity of the carriage 6. The operator determines afte that by means of the adjustment means 29 the angular velocity fo the pivoting movement of the jet tube so that the nozzle 14 wil move with substantially the same speed along the guide 5 as th velocity of the carriage 6. The operator adjusts after that th time delaying means mentioned, so that the movement of th carriage 6 along the guide 5 is not started until substantiall simultaneously as the pivoting of the jet tube 7 about the axi 13 is terminated.

The following function is obtained after these adjustments: Whe the carriage 6 moves in the direction towards one of the en positions according to the arrow 39 in Fig 2 and 4, the jet tub 7 will oscillate about the axis 15 while the jet tube not move with respect to the axis 13, so that the nozzle of the jet tub will in an inclining position be directed in the direction o movement 39 of the carriage. The nozzle 14 will thereby scan th surface of the underlayer to be processed in the way indicated i Fig 2. When the carriage 6 reaches one of its end positions it is stopped by the control unit 16, which simultaneously by means of the control means 35 cause a movement of the vehicle 1 over the distance set and by means of the control means 38 starting of the pivoting of the jet tube 7 about the axis 13 in order to turn the jet tube between the positions in Fig 2 and 3. The carriage 6 is standing still during the entire pivoting of the jet tube 7 and the control unit 16 starts the carriage 6 for movement towards the second end position (arrow 40 in Fig 3) not before substan¬ tially simultaneously as the jet tube finishes its turning. This means that every movement of the nozzle 14 in the direction of one of the arrows 39 and 40 will be composed by on one hand the pivoting movement of the jet tube 7 and on the other a displace¬ ment movement of the carriage 6. The moving path described by the nozzle 14 during the movement in the direction of the arrow 39 is schematically indicated in Fig 3 by a continuous line, while the

movement path described by the nozzle 14 on the movement in the direction of the arrow 40 is illustrated by dashed lines.

The oscillation of the jet tube 7 about the axis 15 in combi¬ nation with the oblique direction of the jet tube towards the surface to be treated about the axis 13 lead to an eminent function also in difficult tasks, such as removing concrete around the enforcement bars located in the concrete layer. It would of course be possible in troublesome conditions to adjust the control unit 16 so that the vehicle 1 is not moved to a greater extend than that the jet tube 7 scans the same surface at least twice with the jet tube in differently adjusted positions about the axis 13.

It is evident that the invention is not restricted to the embodi¬ ment described. The carrier 1 must for instance not necessarily be a vehicle but could instead have the character of a carriage movable along a stand arranged in a suitable way. Furthermore, the device is not at all restricted to processing of horizontal surfaces, but it may also be orientated for processing of verti¬ cal or inclined surfaces. The guide 5 must not necessarily be rectilinear, but it could for instance be curved in correspon dence with the curving of a surface to be processed. The guide 5 could for the rest be adjustable into acute angles with respec to the normal direction of movement of the carrier 1 if this i required by the conditions. It has been described above ho starting of the carriage 6 after a stop in an end position i delayed by means of a time delaying means until the jet tube has finished its pivoting in order to turn. As an alternativ thereto it would be possible to arrange a further detecting mean reacting when the jet tube reaches its extreme pivot position and then delivering information to the control unit 16, which i response to such information immediately starts the movement o the carriage 6. Other control principals could also be used here Finally, it should be mentioned that it will be suitable fo different tasks that the jet tube 7 is so directed that it nozzle 14 points in the direction of a normal to the surface t

be processed, as seen parallely to the axis 13. The control uni 16 is accordingly arranged to unable setting of such a positio of the jet tube. However, also such a position requires for goo processing function oscillating of the jet tube about the axi 15. Other modifications are also possible within the scope of th inventional idea.