EP3415277B1 - Blasting machine for preparing surfaces and protection device for such a blasting machine - Google Patents

Description

Technical area

The invention relates to a blasting device according to the preamble of independent claim 1 for the processing of surfaces, such as the blasting of writings in natural stones by means of a blasting head and a protective device for such a blasting device according to the preamble of independent claim 10. Such a blasting device and such Protective devices are from the document EP 0 350 965 A2 known.

State of the art

Dust-free blasting devices have a brush sleeve to seal the surface of the object to be processed, usually a natural stone, so that the blasting head must always be guided horizontally if the required to withdraw the blasting media and the dust with subsequent separation of the dust from the blasting media Sealing should be maintained.

From the DE 39 39 005 A1 a particle blasting device is known which works dust-free and in which a blasting head with a nozzle is held on a workpiece and the sandblast emerging from the nozzle is operated manually. The jet head rests on the object and is sealed off from the workpiece by means of sealing brushes. The disadvantage here is that it is not possible to see the area to be processed on the surface. Another disadvantage is that machining is only possible in one machining direction perpendicular to the surface, since otherwise the tightness is lost.

The blasting head is connected to a dust-free sandblasting device by means of an abrasive hose for feeding the abrasive and with a return hose for the abrasive and the dust. In order for the work to be dust-free and for the blasting media and dust to be sucked back properly, the negative pressure must assume a certain value.

For the production of plastic decorations, for the creation of which a nozzle of the blasting device must be held at the appropriate angle to the surface, blasting cabins are known, as they are in EP 1 724 063 B1 are described.

The WO 2005/095057 A1 describes a blasting device with a blasting head which is arranged rotatably within the housing and executes a predetermined rotational movement.

The EP 0 350 965 A2 describes a blasting device with a flexible, movably arranged blasting nozzle (modeling nozzle) and a viewing window.

The U.S. 5,601,479 A describes a blasting device with a blasting nozzle arranged movably on the housing in the form of a blasting gun. A viewing window does not seem to be provided.

The U.S. 4,095,378 A also describes a blasting device with a rotatable blasting head.

The FR 2 802 838 A describes a manageable radiation protection device with a viewing window, an engagement and a passage for a blasting medium hose.

The U.S. 4,375,740 A also describes a handleable blasting device with a viewing window and with a blasting gun that can be handled from the outside.

The GB 2 021 450 A also describes a manageable blasting device with an externally manageable blasting agent gun.

The U.S. 3,149,445 A describes a blasting device with a blasting agent nozzle arranged movably within the blasting device, as well as a viewing window and access openings.

The DE 86 22 315 U1 describes a blasting device with a viewing window with access openings and a flexibly designed hose receptacle within the upper housing wall and a part of the sandblasting hose with nozzle located inside the housing.

DE 10 2008 013 697 A1 describes a blasting device with a viewing window and access openings.

Presentation of the invention

The blasting device according to the invention with blasting medium return according to independent claim 1 has a nozzle holder with a tip with a modeling nozzle from which the blasting medium emerges in a pressure jet onto an object to be processed. The nozzle holder is movably arranged in a protective device towards the object to be processed and has an at least partially open jet hood, the jet hood having a lower edge for placing on the object to be processed. Above the lower edge there is an air inlet and a discharge nozzle connected to a suction chamber, the suction chamber being arranged opposite the air inlet. The nozzle holder is movably arranged above the lower edge. The jet hood has a viewing window and access openings with sealing rosettes that allow access, or with sealing gloves, to guide the nozzle holder with the modeling nozzle at the tip by hand. The blasting hood also has a hose guide for a blasting agent hose emanating from outside the blasting hood, the blasting agent hose being guided into the interior of the blasting hood via the guide.

The use of a jet hood allows the creation of ornaments and plastic decorations without the need for a large cabin. Such cabins are very expensive and require a corresponding amount of space. Provided with such a blasting hood, the blasting device can, on the one hand, enable sufficient return of blasting medium and abrasion and, with good placeability, provide a sufficient seal.

The nozzle holder on the sandblasting hose can be moved freely upwards, downwards and to each side within the hood.

The viewing window enables the user to optically follow the nozzle holder with the modeling nozzle during processing. The viewing window can be spaced from the lower edge.

Access openings with sealing rosettes or sealing gloves have the advantage that the escape of blasting media during manual handling is reduced or prevented.

A hose guide makes it easier to move or catch up with the abrasive hose to align the nozzle holder with the workpiece. The hose is sufficiently flexible to allow safe handling. The hose can also have a bellows opposite the guide be sealed and at the same time be longitudinally movable.

The air inlet can advantageously be at least one opening in the housing wall of the jet hood and the opening can be covered by means of a shielding plate arranged at a distance from the air inlet relative to the interior of the hood, the shielding plate being set back in height relative to the lower edge, so that When the jet hood is placed on the object to be processed, a gap is created between the shielding plate and the object.

In this way, a uniform air flow can be provided over the entire base area of the jet hood.

The lower edge advantageously has a low-friction coating facing the object. This makes it possible to move the jet hood along the surface with less effort. For example, PTFE comes into consideration as a material, with a layer thickness of less than 1 mm being sufficient.

The lower edge can advantageously have a seal made of an elastically deformable material. A suitable material for this is, for example, a pore rubber such as foam rubber.

Advantageously, a brush strip with bristles can be arranged around the lower edge, which can in particular assume at least two operating states, namely on the one hand a sealing position protruding laterally and downward over the lower edge and a neutral position in which the bristles of the brush strip are above the lower edge . This can damage the bristles can be avoided during transport or storage of the jet hood.

Advantageously, the jet hood can taper away from the lower edge upwards, that is to say towards the user, and can in particular be conical in shape. This improves the handling of the jet hood.

In the case of a hose guide, the guide can preferably surround the hose with the formation of a narrow gap, in particular less than 1 mm, and thereby have a length which corresponds at least to the hose diameter.

To further improve the feeding of the blasting hose, a guide means for the blasting hose, in particular a guide roller, can be arranged on the blasting hood at a distance from the hose guide. In this way, the blasting agent hose aligns itself in a low-friction and kink-free manner for guidance in the blasting hood and length compensation is possible if the user wants to align the nozzle differently.

Advantageously, the inside of the hood can be provided with a wear-reduced elastic coating. Since the abrasive used inside the blasting hood has an abrasive effect, the service life can be extended. The viewing window and the cover plate for the interior lighting can also have a wear-reducing coating, which, however, must be transparent.

Another object of the invention is a protective device for a blasting device according to claim 10 for processing an object by means of a blasting agent, which has a blasting hood with a lower edge for placing on the object to be processed, the blasting hood has a lower edge to be placed on the object to be processed and an air inlet arranged above the lower edge as well as a discharge nozzle also arranged above the lower edge with a corresponding suction chamber, which is arranged opposite the air inlet and has at least one viewing window and furthermore having one in one Hose guide arranged on the side wall of the hood for a blasting agent hose that extends from outside the blasting hood and is guided into the interior of the blasting hood.

Such a jet hood can be used as a protective device in a jet device.

The guide can advantageously surround the hose with the formation of a narrow gap, in particular <1 mm, and preferably have a length which corresponds at least to the hose diameter. This ensures good feed and adequate sealing.

Advantageously, the hose can be sealed off from the guide by means of a bellows and at the same time can be displaced in a longitudinally movable manner.

The suction chamber can advantageously have a flow plate which is set back in height relative to the lower edge and has a gap to the object. This provides a suction cross-section that is uniform over the width of the suction chamber.

Advantageously, the flow cross-section of the suction chamber can increase towards the extraction nozzle, so that sufficient space is available for the sucked-in air over the entire length of the suction chamber.

The jet hood according to the invention can be conical and either angular or round. A viewing window The tip of the jet hood allows a view of the modeling nozzle, the viewing window being easily exchangeable so that it can be exchanged in the event that the view is clouded due to wear and tear.

The blasting device is operated either via a foot or hand switch, which interacts with the blasting device and switches the provision of the blasting agent on and off on the one hand and the blasting medium recovery on the other.

Brief description of the drawings

Fig. 1

Eine Strahlhaube einer Strahlvorrichtung in perspektivischer Ansicht;

Fig. 2

eine Draufsicht auf die Strahlhaube aus Fig. 1;

Fig. 3

einen Schnitt durch die Strahlhaube aus Fig. 1 2 entlang der Linie CC;

Fig. 3A

eine Absaugkammer im Detail;

Fig. 3B

eine Einströmkammer im Detail;

Fig. 3C

eine erste Ausführung einer Dichtung mit einem elastischen Dichtungsmaterial;

Fig. 4

eine Strahlhaube mit einer Führung, die einen Faltenbalg und eine Bürstendichtung aufweist;

Fig. 4A

eine Bürstendichtung im Detail;

Fig. 4B

eine Innenbeleuchtung im Detail.

An exemplary embodiment of the invention is shown in the drawing. It shows:

Fig. 1

A jet hood of a jet device in a perspective view;

Fig. 2

a top view of the jet hood Fig. 1 ;

Fig. 3

a section through the jet hood Fig. 1 2 along the line CC;

Figure 3A

a suction chamber in detail;

Figure 3B

an inflow chamber in detail;

Figure 3C

a first embodiment of a seal with an elastic sealing material;

Fig. 4

a jet hood with a guide having a bellows and a brush seal;

Figure 4A

a brush seal in detail;

Figure 4B

interior lighting in detail.

Embodiments

In Fig. 1 a blasting hood 1 of a blasting device for blasting ornaments and plastic decorations, which is at least partially open towards an object to be processed, is shown. The jet hood 1 is conically tapered and has an angular base area on a lower edge 2 directed towards the object to be processed. The base can also be round. The jet hood is designed to be placed on flat objects, but can also be modified for curved surfaces with a corresponding design of the lower edge.

The jet hood 1 has side walls 3a-3d extending from the lower edge 2 in a direction away from the object, of which a left side wall 3b as seen by a user and a rear side wall 3c, also referred to as the rear wall, are shown. The front side wall 3a facing the user and the right side wall 3d can be seen in this illustration via an exchangeable viewing window 4 on the upper edge 5 of the jet hood 1, which gives the user a view from above of a viewpoint arranged in the jet hood in FIG Fig. 2 modeling nozzle 6 shown allows.

Above the lower edge 2, on the rear side 3c, a trigger nozzle 7 is arranged, which is provided with an in Fig. 3 shown, arranged in the interior of the jet hood 1, the suction chamber 8 cooperates with a flow plate 8 'and with an inlet gap 9 spaced from the surface of the object to be processed. Also above the lower edge 2 is opposite to the suction chamber in the side wall 3d as in FIG Fig. 2 At least one air inlet 10 is shown, here in the form of several inlet openings provided parallel to the lower edge 2 at the same height. The cross-section of the inlet openings is dimensioned such that the air inlet 10 overall enables a sufficient flow of air into the interior of the jet hood 1 and the resulting air flow reaches a sufficient flow speed to remove particles of the blasting material and the processed object over the entire base area of the jet hood To carry away the suction chamber 8. The minimum speed is assumed here to be 18 m / s, as otherwise blasting media will fail.

A return hose (not shown) for returning the blasting agent and the dust to a blasting device (not shown) with dust separation is connected to the suction nozzle 7. The negative pressure generated in the blasting device and transferred to the suction chamber via the return hose and the suction nozzle ensures the cross-flow and return of the blasting agent in the blasting hood.

As in section CC Fig. 2 in Fig. 3 As shown, the jet hood on the side wall 3d having the air inlet has an inflow chamber delimited by a shielding plate 11, into which the air coming from the inlet openings 10 flows and which has a flow gap 12 with the surface of the object to be processed when the jet hood hits the object is placed in order to provide an air flow L that is as uniform as possible over the entire base area of the jet hood 1 in the area of the surface to be processed. The air flow L illustrated by the arrows then flows out of this gap 12 to the suction chamber 8 located on the opposite side, which has the flow plate 8 'with the gap 9, and then from the suction chamber 8 into the exhaust nozzle 7, to which a dedusting system is connected which provides a retraction of the abrasive, as it is known from dust-free blasting devices with withdrawal of the blasting agent and separation of the dust.

In the Figures 3A, 3B the jet hood is shown in an enlarged section, from which the position of the shielding plate 11 and the suction chamber 8 as well as the respective associated gaps 12 and 9 result.

As in Figs. 1 to 3 and in Figure 3C Shown in detail, a seal 13 made of an elastically deformable material such as rubber or another elastomer is provided on the lower edge 2 of the jet hood 1, which is used when the jet hood 1 is placed on the object to be processed to seal the interior from the environment.

In addition to the seal 13, a brush strip, which will be described later, can also be used.

To improve the sliding properties, the seal 13 is provided on the lower edge 2 of the jet hood 1 with a coating 13.1 made of PTFE, which itself is also elastic and follows the deformation of the seal.

In Fig. 1 it is also shown that the jet hood 1 has a guide 14 for a sandblasting hose 15 on the side wall 3c below the upper edge 5, which is guided via this guide 14 from outside the jet hood 1 into the interior of the jet hood 1. A guide means 16 in the form of a guide roller for the sandblasting hose 15 is arranged on the blasting hood 1 at a distance from the guide 14 in order to facilitate the feeding of the sandblasting hose 15. Depending on the distance and where the nozzle is inside the hood, the hose has to be longer or shorter inside the hood and if it is bent, for example to hold the nozzle at an angle to the user, it must be particularly long.

If the nozzle is held perpendicular to the stone surface, then the jet exits perpendicular to the surface and removes material from the surface below the jet. In this case, the sandblasting hose 15, which is introduced essentially centrally into the blasting hood 1, is fairly straight and usually short, unless the blasting in the blasting hood is at a significant distance from the guide 14.

If the nozzle is tilted away from the operator, specifically against the insertion side, then the sandblasting hose 15 has to make a larger loop because, due to its rigidity, it approaches the nozzle holder with a slight radius and is not angled. In this case, more hose length is required inside the jet hood 1, and undercuts such as rose petals or rose buds, which taper downwards again, can then also be introduced at this angle. The angle of the guide 14 itself is only important to the extent that the nozzle can be held at the appropriate angle and that there is space for this and that the hose length can be fed in and out again in a variable manner.

The jet hood 1 also has an engagement opening 17 arranged on each of the side walls 3b, 3d, which is at least partially sealed with a sealing rosette 18 or closed with sealing gloves (not shown) so that the user can use the modeling nozzle 6 ( Fig. 2 ) can lead manually.

As in Figs. 1 and 2 an interior lighting 19 is shown in the rear wall 3c below the guide 14, which improves the view of the object to be processed and thus facilitates the guidance of the modeling nozzle for the user. The illuminant of the interior lighting 19 can be replaced from the outside.

As in Fig. 3 As shown, the light is fed into the hood via a recess 20 in the rear wall 3b, which is closed by a transparent cover 21. This cover 21, like the viewing window 4, can be exchangeable in order to be exchanged in the event of wear.

At the end of the sandblasting hose 15 located in the interior, also referred to as the tip, a modeling nozzle 6 is attached, with which the sandblast emerging from the nozzle under pressure can be manually guided so that, due to the flexibility of the sandblasting hose 15, the blasting agent jet is inclined at an angle compared to a surface to be processed is possible. In this way, ornaments with inclined surfaces and, if necessary, undercuts can be produced in the surface to be processed.

At the in Fig. 4 The beam hood shown is additionally sealed at the lower edge 2 by means of a brush seal 31. The interior lighting 19 is arranged on the side wall 3c.

As in detail in Figure 4A shown, the brush seal 31 on each of the side walls 3a-d ( Fig. 1 ) the jet hood has a brush strip 32 with bristles 33 of a length of approx. 30-60 mm, the brush strip 32 being arranged via a hinge 34 at a distance from the lower edge 2 that is smaller than the bristle length, so that the bristles 33 protrude laterally over the lower edge 2. The hood is still sitting on its lower edge 2 on the workpiece, but since ornamental cutouts have already been made in the workpiece, the hood can no longer seal satisfactorily and the blasting agent, which is accelerated to 150 m / s, would bounce out. In order to prevent this, the bristles 33, 33 'are so soft that they rest on the stone and compress where it is high, shown as bristles 33', but also penetrate into the recess of the workpiece, shown as bristles 33, in order then, together with the negative pressure that prevails in the hood via the back suction of the blasting device, to ensure a sufficient seal.

The brush strip 32 can be pivoted around the joint 34 away from the lower edge 2 into a neutral position towards the side wall 3a, so that it can only be used as required.

As in Figure 4B Also shown in detail, the light is fed into the hood via a recess 20 in the rear wall 3b, which is closed by a transparent cover 21. This cover 21, like the viewing window 4, can be exchangeable in order to be exchanged in the event of wear. The interior lighting 19 can be opened from the outside via a detachable connection 22. A heat sink 23 ( Fig. 4 ) provided, but this can be omitted if there is no great heat development.

Furthermore, in Fig. 4 a seal between the guide 14 and the hose 15 is shown by means of a bellows 41 which is tightly attached to the guide 14 on the one hand and to the hose 15 on the other. Due to the deformability of the With bellows in the longitudinal direction, the hose 15 can be drawn into the interior space over a certain length and pushed out of the interior space when the operator guides the nozzle 6 over the surface to be processed.

It is pointed out once again that the extraction nozzle and the suction chamber are connected to the suction of the known dust-free blasting device of the dust-free blasting device by means of a suction hose. This means that two hoses of the dust-free blasting device go to the hood, on the one hand the abrasive hose and on the other hand the suction hose.

Claims (14)

1. A blasting device with blasting medium recirculation, having a nozzle holder (6) with a tip having a modeling nozzle, from which the blast medium exits in a pressurized jet (6') onto an object to be treated, wherein the nozzle holder (6) is movably arranged in a protection device which has a blasting hood (1) which is at least partially open towards the object, wherein the blasting hood (1) has a lower edge (2) for fitting on the object to be treated and an air inlet (10) arranged above the lower edge (2) as well as a discharge connection (7) likewise arranged above the lower edge (2) having a suction chamber (8) which is arranged opposite the air inlet (10), wherein the nozzle holder (6) is movably arranged above the lower edge (2), wherein the blasting hood (1) has at least one inspection window (4), characterized in that the blasting hood (1) has engagement openings (17) having sealing rosettes (18) or sealing gloves, in order to manually guide the nozzle holder (6) having the modeling nozzle on the tip, and the blasting hood has a hose guide (14) for a blasting medium hose (15) starting from outside the blasting hood, wherein the blasting medium hose (15) is guided via the guide (14) into the interior of the blasting hood (1).
2. The blasting device according to Claim 1, characterized in that the air inlet (10) is at least one opening (10) in a side wall (3d) of the blasting hood and the opening (10) is covered with respect to the interior of the blasting hood (1) by means of a shielding plate (11) arranged at a distance from the air inlet, wherein the shielding plate (11) is set back in its height with respect to the lower edge (2) so that a gap (12) is created between the shielding plate (11) and the object when the blasting hood (1) is fitted on the object to be treated.
3. The blasting device according to Claim 1 or 2, characterized in that the lower edge (2) has a low-friction coating (x) facing the object.
4. The blasting device according to any one of Claims 1 to 3, characterized in that the lower edge (2) has a seal (13) made of an elastically deformable material.
5. The blasting device according to any one of Claims 1 to 4, characterized in that a brush strip (32) having bristles (33) is arranged around the lower edge (2), which brush strip can in particular assume at least two operating states, namely on the one hand a sealing position projecting laterally and downwards beyond the lower edge and a neutral position, in which the bristles (33) of the brush strip (32) lie above the lower edge (2).
6. The blasting device according to any one of Claims 1 to 5, characterized in that the blasting hood (1) tapers upwards away from the lower edge (2), is in particular conical.
7. The blasting device according to any one of Claims 1 to 6, characterized in that the guide (14) preferably encloses the hose (15) configuring a narrow gap (14'), in particular less than 1 mm, and has a length which corresponds at least to the hose diameter.
8. The blasting device according to any one of Claims 1 to 7, characterized in that guide means (16) for the hose (15), in particular a guide roller, are arranged on the blasting hood (1) at a distance from the hose guide (14) in order to compensate for the length of the hose (15).
9. The blasting device according to any one of Claims 1 to 8, characterized in that the blasting hood is provided with a wear-reduced elastic coating (x) on its inside.
10. A protection device for a blasting device for treating an object by means of a blasting medium, which has a blasting hood (1) which is at least partially open towards the object, wherein the blasting hood (1) has a lower edge (2) for fitting on the object to be treated and an air inlet (10) arranged above the lower edge (2) as well as a discharge connection (7) likewise arranged above the lower edge having a corresponding suction chamber (8) which is arranged opposite the air inlet (10) and has at least one inspection window (4), characterized in that a hose guide (14) arranged in a side wall (3c) of the hood is provided for a blasting medium hose (15) which is guided, starting from outside the blasting hood (1), into the interior of the blasting hood (1).
11. The protection device according to Claim 10, wherein the guide (14) encloses the hose (15), configuring a narrow gap (14'), in particular < 1 mm, and preferably has a length which corresponds at least to the hose diameter.
12. The protection device according to Claim 10, wherein the guide (14) encloses the hose (15), which is sealed with respect to the guide via bellows (41) and can be displaced in a longitudinally movable manner.
13. The protection device according to any one of Claims 10 to 12, characterized in that the suction chamber (8) has a flow plate (8') which is set back in its height with respect to the lower edge (2) and has a gap (9) from the object.
14. The protection device according to Claim 13, characterized in that the flow cross-section of the suction chamber (8) increases towards the discharge connection (7).

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