EP0291707B1 - Sandblast cabinet - Google Patents

Abstract

An apparatus for sandblasting a workpiece includes a sandblasting cabinet having an inner sandblasting chamber, a dust extraction system including an air intake disposed in an upper forward portion relative to the cabinet, an upwardly angled sieve disposed in a rearward position inside the cabinet, and a blasting material recovery system including a suspended floor within the sandblasting chamber and a recovery channel disposed beneath the upwardly angled sieve and behind the suspended floor.

Description

The invention relates to a sandblasting cabin, preferably for use for blasting inscriptions and plastic decorations on workpieces, in particular made of stone, glass and wood, with a sound-absorbing cabin construction which has a soundproof roll curtain in which a machine-controlled, driven, movable, height-adjustable jet pipe soundproofed and dust-free sealed, can be moved vertically and horizontally in an XY guide over a workpiece surface to be machined.

Such a sandblasting cabin is already known from British Patent 891, 446.

The known automatic blasting systems for the stone industry have the properties that they run a rectangular field, which is delimited by several limit switches, and thereby carry out the blasting process.

These systems are repeated as often as required and must then be switched off by hand when a sufficient depth of the desired inscription or decoration has been achieved in the workpiece.

The use of time relays or negative-working counters, in which the system switches itself off automatically after a corresponding number of field reversals and when the previously set depth is reached, is also known.

These systems all have the disadvantage that they can only process a rectangular field and, regardless of the size of the space between the individual lines and ornaments to be blasted, process the entire surface of the workpiece.

This mode of operation means that compressed air and abrasive consumption are high, as the blasting time is multiplied unnecessarily.

Furthermore, no sandblasting systems are known in which the sound insulation, taking into account the air flow in the cabin, is sufficient and satisfies the legal requirements.
Mainly in manual operation, the prescribed values cannot be met by the known systems due to their design features.

These systems also do not allow the jet pipe to be moved without an opening or a gap being formed in the rubber seals from which sound and blasting agent emerge. There are also no sandblasting cabins on the market that have a double-manufactured profile frame construction that is lined with sound-absorbing agents.

The blasting agent return, if any, does not correspond to the known systems economic needs. All types of the previous type are subject to high wear, since very large frictional forces occur between the components. The dedusting systems used have also proven to be disadvantageous.
So far, not only has it been possible to remove usable blasting material, but the operator's view has also been considerably impaired by particles swirling around. This consequently affects the quality of work.

The present invention is therefore based on the object of providing a sandblasting cabin which ensures a blasting of material under optimum sound conditions in manual or automatic operation, the control of which permits multi-field processing without dead times, the compressed air requirement, the blasting agent consumption and the blasting time being kept as low as possible, and in which the dedusting is carried out in such a way that the working view is not impaired. Furthermore, the blasting agent return is carried out without wear and tear on components. In addition to a separate control panel, a system with a sandblasting cabin according to the invention also has a separately standing sandblasting fan and separate dedusting system.

This object is achieved according to the invention in a sandblasting cabin of the type mentioned at the outset by that the sandblasting cabin has a control device for automatically controlling the jet pipe for specifying a plurality of rectangular fields of adjustable size to be processed with the jet pipe (multi-field system) and that the sandblasting cabin has a diagonal air change with a gradient sifter and a foundation-free vibrating conveyor floor with pendulum slides and conveyor trough serving for the recovery of the blasting material, whereby The foundation-free vibrating conveyor floor consists of a conveyor frame with pendulum slides arranged one behind the other, which is arranged to work in the sandblasting cabin without wear and can be moved backwards and forwards by means of a cable pull, whereby the pendulum slides can be folded congruently with the conveyor frame movement into a working and rest position via the cable pull.

The measures listed in the dependent claims allow advantageous developments of the sandblasting cabin specified in independent claim 1.

Figur 1

eine Seitenansicht der Sandstrahlkabine;

Figur 2

einen Querschnitt durch die Sandstrahlkabine;

Figur 3

eine Ansicht der Sandstrahlkabine von vorn;

Figur 4

die Strahlschlitzabdichtung;

Figur 5

die Strahlschlitzabdichtung bei Handbetrieb;

Figur 6

einen Querschnitt der doppelt gefertigten Profilrahmenkonstruktion;

Figur 6a

eine perspektivische Darstellung der doppelt gefertigten Profilrahmenkonstruktion;

Figur 7

die Steuerfelder einer Steuereinrichtung der Sandstrahlvorrichtung, an deren vorgesehene Reiter oder Nocken die Grenzen mehrerer rechteckiger, mit einem Blaskopf überstrichener Felder auf dem Werkstück markieren;

Figur 8

die Steuerfelder zusammen mit einem fertigen Werkstück.

With reference to the accompanying drawings, which show a particularly preferred embodiment of the invention, this will now be explained in more detail.
Show:

Figure 1

a side view of the sandblasting cabin;

Figure 2

a cross section through the sandblasting cabin;

Figure 3

a view of the sandblasting cabin from the front;

Figure 4

the beam slot seal;

Figure 5

the beam slot seal in manual mode;

Figure 6

a cross section of the double manufactured profile frame construction;

Figure 6a

a perspective view of the double manufactured profile frame construction;

Figure 7

mark the control fields of a control device of the sandblasting device, on the provided tabs or cams of which the boundaries of a plurality of rectangular fields on the workpiece which are overlaid with a blow head;

Figure 8

the control panels together with a finished workpiece.

FIG. 1 shows a side view of the sandblasting cabin 1. The automatic system 29 with the jet pipe 3 are guided through the standing columns 30, moved up and down. This can be done manually or automatically. The viewing window 24 enables the operating personnel to look into the blasting area.

An air inlet duct 20 is arranged above the blasting cubicle 1, the system of which will be discussed in more detail later.
A special feature of the invention consists in the separate control cabinet 31. The workpiece is moved into the blasting cabinet 1 via the roller conveyor 27. The door 32 is equipped with a door lock and safety circuit.

FIG. 2 shows a cross section through the blasting cubicle 1, into which the workpiece 26 is inserted via the roller conveyor 27. The air inlet is provided with baffles 25 which prevent the blasting material from escaping. The dedusting is carried out via the gradient sifter 4.
The air is discharged in the direction of the arrow. That means that the air is sucked down through the gradient sifter from the baffles 25. With this suction, the dust is also drawn down so that the operator's view is no longer impaired.
A special feature of the invention is that the gradient sifter 4 is located above the conveyor trough 7. The gradient sifter 4 lowers the air speed, the blasting medium which is still usable falling down into the conveyor trough 7.

Another feature of the invention lies in the structural design of the blasting medium return conveyance by means of a vibrating conveyor floor 5. The conveying frame 15, which is provided with a series of pendulum slides 6, is suspended on ropes 18 and is only guided laterally, so that it works without wear. The movement of the vibrating conveyor floor 5 according to h and v is carried out by a permanently working cylinder via cable 16. Also with a cable in this oscillation, when moving to v all pendulum slide 6 are placed in an inclined position (dashed line) so that they are in a kind of rest position.

Only after movement of the vibrating conveyor floor 5 after h, the pendulum slide 6 are put back into the working position, so that the blasting medium is always transported with a small stroke about 30 cm against the conveyor trough. This transport is carried out in the form of a relay, i.e. each pendulum slide feeds the blasting material by about 30 cm to the conveyor trough

The blasting material is drawn off in the pneumatic conveying trough 7 and conveyed into the adjacent silo 22 above the sandblasting blower 21 (FIG. 3), the conveying being carried out with normal dedusting and no separate device being required.

The cable deflections 17 are also located outside the actual cabin, so that again there is no wear. The floor area of the cabin is designed with grating 28.

FIG. 3 shows the front view of the blasting cabin 1, in which the roller blind 2 can be seen.
It can be seen that the automatic seal 8 is incorporated in the roller blind 2 and the jet pipe 3 projects into the cabin 1 without an insertion gap.

If work is now to be carried out by hand, it is possible to divide the automatic seal 8 in the middle, in the region of the jet pipe 3, and roll up the seal parts to the left or to the right, so that the brush seal 19 described in FIG. 5 can be used .
A viewing window 24 is incorporated into the roller blind 2 and halogen floodlights 33 are attached at a special angle for illuminating the beam object. A special feature of the invention is the separate separator 23 with silo 22, sandblasting fan 21 and control cabinet 31.

Figure 4 shows a cross section through the roller blind 2, in which the arrangement of the automatic seal 8 and the two-part rubber seal 10 can be seen. It becomes clear in this illustration that the inlet of the jet pipe guide 9 into the cabin does not open any gap and is therefore designed to be sound-insulating.

FIG. 5 shows a further cross section in which the automatic seal is rolled up and the brush seal 19 is inserted. In this exemplary embodiment, too, there is sufficient sealing to the blasting space.

FIG. 6 shows a cross section of the double-manufactured profile frame construction 12. The extremely favorable sound insulation conditions are due to the interaction between the sound absorbing material 11 and the double-walled profile frame construction 12 clad with steel sheet 52, an air space 53 being formed between the sound absorbing material 11 and the one with spacers 14 provided double impact protection material 13 achieved.

Figure 6a shows a perspective view of the profile frame construction.

The function of the controller is explained below with reference to FIGS. 7 and 8.

Referring to FIG. 7, the control fields 34, 35 make it possible to determine a plurality of rectangular fields on the workpiece 26, which are processed one after the other with the blowing nozzle 3. The number of fields corresponds to that of lanes Ix, IIx, IIIx, IVx or Iy, IIy, IIIy, IVy.
The fields can also partially overlap, with tracks IIIx and IIIy being auxiliary tracks to tracks IVx and IVy, respectively. These auxiliary tracks make it possible to obtain a beam field consisting of several overlapping geometric rectangles. The tabs 36, 37, 38, 39 are arranged on the tracks Ix, Iy that lie on the inside of the control fields 34, 35 opposite the workpiece 26.
The position of these tabs 36, 37, 38, 39 determines the limits of a rectangular field A on the workpiece 26. Tabs 40, 41 can be seen on the next outer track IIx of the control field 34, and on the next outer track IIy of the control field 35 riders 42, 43 are arranged. These four tabs 40, 41, 42, 43 define the limits of a further rectangular field B on the workpiece. Tabs 44, 45, 46, 47 located on the next outer tracks IIIx, IIIy mark the boundaries of a rectangular field C, and tabs 48, 49, 50, 51 located on the outermost tracks IVx and IVy determine a rectangular field D, the the latter fields C / D form a cross shape with changing widths.

The width of the cross bar is thus specified by tabs 48, 49 and its length by tabs 50, 51, while the length of the crossbar is set by tabs 44, 45 and its width by tabs 46, 47. It goes without saying that the position and size of all fields, and thus also the position, size and shape of the cross, can be variably specified within wide limits. The assignment of the tabs to the individual fields A, B, and C / D in accordance with a track sequence matching on both control fields 34, 35 creates very clear conditions for an operator, and the sandblasting device according to the invention can be set up quickly.

Inscriptions can be blasted on fields A, B, while the intersecting fields C / D, which form a unit and are intended for shining a cross ornament. Inscriptions or cross ornaments are each within the field boundaries that are marked with the tabs. Within these fields, work is carried out using conventional sandblasting technology, in particular by partially covering fields A, B and C / D, leaving parties to be processed free or using lettering and ornamental templates. The result of such processing is shown in FIG. 8, the associated tab positions being shown. After preparation of the workpiece, the number of reversals to be carried out per field A, B and C / D is entered on an input unit of the sandblasting device. This number can differ from field to field if you want to achieve different engraving depths. The device can then be started, whereupon it automatically processes one after the other. In the fields C / D the control is carried out in such a way that the cross is swept line by line and with column-wise feed with the blow head; So there is only a simple editing in the intersection of the fields C / D. The running number of reversals is preferably counted. When the specified final number is reached, the next field is automatically switched over and processed accordingly. After completing the last field, the blowing nozzle preferably returns to its starting position.

The invention is not limited to the number of four track pairs and fields shown in the exemplary embodiment. However, with an arrangement of three to five tracks on both control fields 34, 35 and a corresponding number of rectangular fields to be processed, the requirements of practice are generally met.

Reference symbol list

1

Sandblasting cabin

2nd

Roller blind

3rd

Jet pipe / blow nozzle

4th

Gradient classifier

5

Vibrating conveyor floor

6

Pendulum slide

7

Conveyor trough

8th

Automatic sealing

9

Nozzle pipe

10th

two-part rubber seal

11

Sound absorption material

12

double profile frame construction

13

double impact protection rubber seal

14

Spacers

15

Funding framework

16

Cable

17th

Cable redirections

18th

Suspension of the funding framework

19th

Brush seal

20th

Air intake duct

21

Sandblaster

22

silo

23

Separator

24th

Viewing window

25th

Bullying

26

workpiece

27th

Roller conveyor

28

Lattice rose

29

Automatic

30th

Columns

31

switch cabinet

32

door

33

Halogen fullter

34

Control panel

35

Control panel

36 to 51

equestrian

52

Sheet steel

53

airspace

Claims (23)

1. Sand Blasting Cabin (1), preferably to be used for the blasting of inscriptions and plastified ornaments on work pieces, especially made of stone, glass and wood,
   which has a sound-absorbing cabin construction and a sound-rebounding roller curtain (2),
   in which a mechanically governed and driven movable and hight adjustable blasting lance (3) sonorized and dustfree sealed, vertically and horizontally convoyable in an X-Y-direction is guided over the workpiece surface which is to be treated,
   thus characterized
   that there is an automatic device for the automatic guiding of the blasting lance for setting up a number of rectangular working fields of adjustable size (multiple field system) to be worked off with the blasting lance and that the sand blasting cabin (1) has a diagonal air exchangement with climbing sieve (4) as well as a foundationless swinging transportation floor (5) for the blasting material recovery with perpendicular scrapers (6) and suction channel (7), and the foundationless swinging transportation floor (5) which consists of a recovery frame (15) fitted with perpendicular scrapers (6) which are mounted one after the other, which is working without any wear and which moves forwards and backwards like a perpendicular in the sand blasting cabin (1) by means of a rope (16) whereas the perpendicular scrapers (6) are turned by means of the rope (16) in congruence with the movement of the recovery frame into a working and rest position.
2. Sand blasting cabin according to claim 1,
   thus characterized
   that the automatic device has a stiring field in the X- and Y- axle on which operating edges can determine the limits of the working fields the operating edges being infinitely variable.
3. Sand blasting cabin according to claim 1 or 2,
   thus characterized
   that the operating edges have a function like a stop dog for the X-Y-guiding of the blasting nozzle whereas they can especially act together with the final switches of the X-Y-guiding.
4. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that each stiring field has at least one track or several parallel tracks on which at least a pair of operating edges can be situated.
5. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that the number of the main tracks is according to the number of the blasting fields.
6. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that at least in one field changing widths can be obtained and here then several operating edges are needed so that especially fields of cross shape can be worked off.
7. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that at least one input unit belongs to the automatic device where the number of the fields to be treated and/or the free choosable number of reversements per field is pre-adjustable.
8. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that the automatic device is fitted with a number of counters corresponding to the maximum number of working fields whilst each counter counts the number of reversements for a certain field to which it belongs.
9. Sand blasting cabin according to one of the before mentioned claims
   thus characterized
   that the automatic device drives the blasting lance or nozzle after having reached the pre-adjusted number of reversements from one field to the next field and from the last field preferably into the start position again.
10. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that it has an air intake channel (20) which is mounted above the working and viewing space and that in the interior of the sand blasting cabin (1) over a recovery channel (7) there is a climbing sieve aspirating the air to the bottom, mounted in a way that a dust extraction with diagonal air exchangement in the sand blasting cabin (1) takes place and the blasting material which can still be used falls at least partially into the recovery channel (7).
11. Sand blasting cabin according to claim 10,
    thus characterized
    that the air intake channel (20) is fitted with "chicanes" (25).
12. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the rope (16) is activated by a pneumatic cylinder or an electric motor.
13. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the turn arounds of the rope (17) are outside of the blasting room.
14. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the transportation frame (15) is only sidewise guided and works on suspension (18) in the cabin like a perpendicular.
15. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the blasting room is covered with a blasting material penetrating material preferable with grating (28).
16. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that this cabin consists of a double manufactured profile frame construction fitted with sound absorbing material (11) and lined with double rubber material for protection against any wear (13) fitted with distance pieces (14).
17. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the roller curtain (2) is fitted with an automatic sealing (8) through which the blasting lance or nozzle (3) beared in a special adapted guiding (9) goes into the sand blasting cabin (1).
18. Sand blasting cabin according to claim 17,
    thus characterized
    that the automatic sealing (8) guided by means of a rope and a spring balance is to be opened in the middle and can be rolled up to the left and the right.
19. Sand blasting cabin according to claim 17 or 18,
    thus characterized
    that behind the roller curtain (2) at the side which is situated next to the blasting room a rubber sealing (10) is fixed, behind which there are channels where the blasting material can flow back again into the sand blasting cabin (1).
20. Sand blasting cabin according to one of the claims 17 - 18,
    thus characterized
    that a brush sealing (19) can be mounted on and off at the range where the automatic sealing (8) is rolled up.
21. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that roller curtain (2) is fitted with at least one viewing window (24).
22. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that the workpieces to be treated (26) can be put into the blasting room by means of a roller track (27) which is mounted crosswise through the sand blasting cabin (1).
23. Sand blasting cabin according to one of the before mentioned claims
    thus characterized
    that this cabin has a separate dust extraction unit and sand blasting apparatus (21) with storage hopper (22) and separator (23).

Images