WO1997018923A1

WO1997018923A1 - Device for dust-free abrasive blasting, painting and high-pressure washing of surfaces

Info

Publication number: WO1997018923A1
Application number: PCT/FI1996/000599
Authority: WO
Inventors: Hannu Antero Koskinen
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-11-22
Filing date: 1996-11-07
Publication date: 1997-05-29
Anticipated expiration: 1998-05-22
Also published as: FI2239U1; FIU950488U0

Abstract

The invention relates to an improved blast apparatus, in which the blast nozzle (16) during transport in the direction of the main cylinder (10) is brought to execute a torsional movement in the plane of the nozzle, cutting across the working direction of the main cylinder, whereby the jet of blast medium will perform a sweeping motion laterally. Additionally, the jet of blast medium can be brought to hit the surface in an oblique angle so that the jet is constantly directed slightly against the working direction of the main cylinder. Furthermore, the blast nozzle can be enclosed in a protective cover (20), the opening (21) of which can be pressed against the object under work. Hereby it is possible to carry out other types of surface treatment, for example, washing and painting, in the immediate vicinity of the blast automaton. If whished, the blast apparatus can be provided with nozzles for washing and painting.

Description

Device for dust-free abrasive blasting, painting and high-pressure washing of surfaces

The present invention relates to an apparatus for dust-free blasting, high-pressure washing and painting of surfaces, especially hulls, oil storage tanks, facades of houses, bridges and other constructions .

5 An existing type of blast automatons for the blasting of facades and the like comprises a horisontally directed, pneumatically operated cylinder, which transports laterally a blast nozzle located outside the cylinder. The blast nozzle, which is stationary with respect to the carrier 0 plate on which it is anchored, is directed perpendicularly to the working direction of the cylinder.

The disadvantage of this apparatus is that the jet from the nozzle hits a very limited area of the object under work. Each time the cylinder moves from one end position to the 5 other end position, the apparatus treats an area consisting of a very narrow strip. Since the blast medium hits the work area almost perpendicularly, the removing of rust, old paint or the like is less effective than if the nozzle would be directed in an oblique angle to the work area.

0 Another disadvantage of a blast automaton of the above described type is that the apparatus creates large amounts of dust originating from the blast medium and material which has been removed from the area being treated. Because of the dust it is impossible to perform any other work 5 phases, such as painting, in the vicinity of the place where the blasting is being carried out.

The object of the present invention is to provide an improved blast apparatus, in which the blast nozzle during transport in the direction of the main cylinder is brought to to revolve in the plane of the nozzle, which cuts across the working direction of the main cylinder, whereby the jet of blast medium will perform a sweeping movement laterally. Furthermore the jet of blast medium can be brought to hit the surface in an oblique angle so that the jet is constantly slightly directed against the working direction of the main cylinder. Additionally the blast nozzle can be enclosed in a protective cover the opening of which may be pressed against the object under work. By means of this it is possible to perform other surface treatment, for example, washing and painting, in the immediate vicinity of the blast automaton. Thereby the blast apparatus may, if wished, be provided with nozzles for washing and painting.

The characteristics of the invention will be evident from claim 1.

The invention will be described in detail with reference to the enclosed drawings, in which

Figure 1 shows the working principle of a main cylinder according to the prior art, Figure 2 shows a blast apparatus according to the invention comprising a protective cover and components connected to it,

Figure 3 shows a side view of the apparatus of Figure 2,

Figure 4 is a schematic side view of a section through the main cylinder according to Figure 3, and

Figure 5 is a schematic horisontal view of a blast apparatus provided with means for other surface treatment.

Figure 1 shows the principle for a pneumatically operated cylinder 10 without a piston rod, which is known per se, and which is being used as a main cylinder in the present invention. In the vertically directed cylinder 10 the piston 11 runs upwards and downwards, respectively, under the impact of pressurized air. A loop consisting of a wire or a band 12 is attached to the piston 11, said wire or band runs through a hole in the upper end of the cylinder 10 (not shown in the Figure), is directed downwards over an upper roller bearing 13 and back again upwards over a lower roller bearing 14 and back into the cylinder 10 through a hole in the bottom of the cylinder (not shown in the Figure). An anchorage block 15 for a nozzle (nozzle abutment) is attached to that part of the wire or band loop which will be positioned on the outside of the cylinder in every position of the piston.

Figure 2 shows a blast apparatus according to the invention, in which the blast nozzle 16 has been enclosed in a protective cover 20. The actual main cylinder 10 and the anchorage components of the blast nozzle 16 are positioned externally of the protective cover. The opening 21 of the protective cover, which is encircled by the edge 22, is directed towards the viewer. When the apparatus is being used the opening 21 of the cover is pressed against the object under work. The dust is suctioned away through the suction pocket 24 and the suction hose, which is connected to the outlet 23 in the bottom portion of the cover. The protective cover preferably comprises an inner cover 25 and an outer cover 26, whereby the space between the two covers 25 and 26 is advantageously about 50 mm. The edge 22, which is being pressed against the object under work is preferably provided with a rubber seal having suction slits 27 for dust. The blast nozzle 16 is by means of a torsional engine 19 coupled to the nozzle table 18, which in its turn is connected via a torsional cylinder 17 to the nozzle abutment 15 (Figure 4) attached to the band of the main cylinder 10.

Figure 3 shows a side view of the blast apparatus. The actual main cylinder 10 and the fastening and control means for the blast nozzle connected to it (not shown in the Figure) are positioned on the opposite side of the protective cover 20 with respect to the opening 21 of the cover. Figure 4 shows in greater detail the arrangement according to the invention. The nozzle table 18 is by means of a torsional cylinder 17 attached to the nozzle abutment 15. In this embodiment two successive blast nozzles 16 and 16', which extend into the protective cover through a slit enabling the nozzles (16, 16') to move with respect to the wall of the protective cover, are attached by means of a respective torsional engine 19 and 19' to the nozzle table 18. The torsion occurs in the direction shown by arrows along the vertical axes 30 and 31', respectively, of the torsional engine. As a result of this the nozzles 16 and 16' will perform a sweeping motion in the horisontal plane. In practice a turning of about 30° in each direction should be appropriate. As a result of said sweeping motion the blast medium will come into contact with a wide area of the work area during each travel downwards and upwards . During operation the nozzle table 18 is located in a plane slightly deviating from the horisontal plane. The torsional cylinder 17 accomplishes a turning around its horisontal axis 32 in the direction shown by arrows. As a result of this the nozzle table 18 and thus the nozzles 16 and 16', may be directed upwards or downwards, whereby the jet of blast medium can be brought to hit the work area in an oblique angle. Furthermore it is desirable that the jet of medium is directed slightly against the working direction of the main cylinder, i.e. the jet of medium and said working direction should form an angle smaller than 90°, preferably about 75°. This is achieved by means of turning the nozzle table with the adherent nozzle 15° in a downwards direction with respect to the horisontal plane when the nozzle abutment together with the components connected to it starts its course downwards . Correspondingly the nozzle table should be turned 15° in an upward direction when the nozzle abutment starts its course upward. Thus the torsional cylinder 17 achieves a total turning of 30° each time the nozzle abutment passes by its upper and lower end position. When the blast nozzle has been enclosed in a protective cover, it is possible to perform other types of surface treatment, for example, washing and painting in the immediate vicinity of the blast automaton. According to an advantageous embodiment schematically shown in Figure 5, the blast automaton is furthermore provided with one or more nozzles for high-pressure washing and painting. The high-pressure washing nozzles 40 and the painting nozzles 42 are by means of auxiliary arms 41 and 43, respectively, mounted to the nozzle table 18 outside the protective cover 20. The high-pressure washing nozzles 40 are located upstream of the protective cover in the driving direction of the apparatus (shown by an arrow), at a suitable distance, for example, 1 to 1.5 metres, preferably 1.2 metres. The painting nozzles 42 are located on the opposite side of the protective cover, and advantageously at the same distance, i.e. preferably 1.2 metres.

In many cases the simultaneous performance of all the work phases, i.e. washing, blasting and painting, will not cause any problems. On the contrary, it may well involve several advantages in the form of gain in time in, for example, shipyards and vessels in port.

Owing to the use of a protective cover the environment is protected from the dust originating from the blast medium waste and particles which have come off the prepared surface.

The apparatus according to the invention may advantageously be automatized and driven by automatic lifts. By means of special suspension means the apparatus can be mounted to the working car or hydraulic arm of the lift. By this the operating height will not be limited.

Since pressurized air is needed for the surface treatment in itself, all the torsional cylinders, torsional engines and others, are suitably pneumatically operated. The automaton can be controlled by means of logic components of the type no-not valves.

In the above example the main cylinder is vertically directed. In some embodiments it may, however, be suitable to direct the main cylinder in another position.

It is obvious for a person skilled in the art that the various embodiments of the invention may vary within the scope of the claim.

Claims

1. An apparatus for dust-free blasting, high-pressure washing and painting of surfaces, especially hulls, oil storage tanks, facades of houses, bridges and other constructions, comprising one or more blast nozzles (16) connected to a nozzle abutment (15) in a pneumatically operated main cylinder (10) without a piston rod, characterized in that the apparatus further comprises - a nozzle table (18), which by means of a torsional cylinder (17) is mounted to the nozzle abutment (15) of the main cylinder (10), whereby said torsional cylinder, when the nozzle abutment is in the end position of the main cylinder, is arranged to turn the nozzle table around an axis (32) directed almost perpendicularly to the longitudinal direction of the main cylinder (10), - a torsional engine (19), which connects the blast nozzle (16) to the nozzle table (18), whereby the torsional engine (19) is arranged to turn the blast nozzle (16) in a plane cutting across the longitudinal direction of the main cylinder (10), and - a protective cover (20) enclosing the blast nozzle (16), whereby the protective cover is provided with a slit so that it is possible for the blast nozzle to move in relation to the protective cover and an opening (21) intended to be pressed against the object under work.

2. An apparatus according to claim 1, characterized in that it further comprises nozzles (40, 42) for high-pressure washing and painting, whereby said nozzles have been connected to the nozzle table (18) by means of auxiliary arms (41, 43 respectively).