BLASTING CONTAINER

Abstract

A blasting container for blasting workpieces with blasting medium has a wall that is provided with outlet openings for blasting medium. Covers are located at the outer side of the wall above the openings.

Claims

1. A blasting container for blasting workpieces with a blasting medium, said blasting container comprising at least one wall having an inner side and an outer side, wherein the wall is provided with a first and at least one further opening for a discharge of blasting medium, wherein a cover is located at the outer side of the wall above the first and above the further opening, with a passage for blasting medium being formed between the cover and the opening covered by said cover.

2. The blasting container according to claim 1, wherein the cover completely covers the opening.

3. The blasting container according to claim 2, wherein the area of the cover is larger than that of the opening.

4. The blasting container according to claim 1, wherein the cover is planar in the region of the opening.

5. The blasting container according to claim 1, wherein the geometry of the outer contour of the opening and the cover is the same.

6. The blasting container according to claim 1, wherein the cover has margins that are curved in the direction of the wall.

7. The blasting container according to claim 1, wherein the wall has opening margins that are curved in the direction of the cover.

8. The blasting container according to claim 1, wherein the cover is provided with elevations at its side facing the opening.

9. The blasting container according to claim 1, wherein the cover is fastened to the wall.

10. The blasting container according to claim 1, wherein it is double-walled, with the wall having the openings being an inner wall that is surrounded by an outer wall that is provided with the covers.

11. The blasting container according to claim 10, wherein the outer wall is also provided with openings for a discharge of blasting medium, said openings being arranged offset from the openings of the inner wall.

12. The blasting container according to claim 1, wherein the wall is formed in the region of a recess by an insert that is inserted into the recess, with the insert having the openings and at least one cover being fastened to an outer side of the insert.

13. A method for blasting workpieces with blasting medium in a blasting container, said blasting container comprising at least one wall having an inner side and an outer side, wherein the wall is provided with a first and at least one further opening for a discharge of blasting medium, wherein a cover is located at the outer side of the wall above the first and above the further opening, with a passage for blasting medium being formed between the cover and the opening covered by said cover, wherein the maximum clear width of the openings is W.sub.max, and the maximum dimension of the workpieces is L.sub.max, wherein L.sub.max is greater than W.sub.max.

14. The method according to claim 13, wherein the maximum dimension of the blasting medium is S.sub.max, and the minimum clear width of the passage is in the range from 3 S.sub.max to 5 S.sub.max.

15. The method according to claim 13, wherein the maximum dimension of the workpieces L.sub.max is greater than or equal to the product of the maximum clear width D.sub.max of the passage and the maximum clear width of the opening W.sub.max, divided by the minimum dimension L.sub.min of the workpieces.

16. The method according to claim 13, wherein the workpieces are at least sectionally configured as rod-shaped, pin-shaped, blade-shaped and/or tapering to a point.

17. A blasting system comprising a blasting container and a blasting device for applying blasting medium to workpieces located in the blasting container, said blasting container comprising at least one wall having an inner side and an outer side, wherein the wall is provided with a first and at least one further opening for a discharge of blasting medium, and wherein a cover is located at the outer side of the wall above the first and above the further opening, with a passage for blasting medium being formed between the cover and the opening covered by said cover.

Description

[0029] The present invention will be described in the following purely by way of example with reference to advantageous embodiments and to the drawing. There are shown:

[0030] FIG. 1 a part section through the wall of a blasting container;

[0031] FIGS. 2a) to h) highly schematized sections through a wall, similar to the representation in FIG. 1;

[0032] FIG. 3 a workpiece extending partly through an opening of the wall;

[0033] FIG. 4 a perspective view of a blasting container;

[0034] FIG. 5 a partly sectioned view of an insert for the blasting container of FIG. 4; and

[0035] FIG. 6 to FIG. 8 representations of components of the insert.

[0036] FIG. 1 shows in a highly schematic and purely exemplary manner a section through a wall 10 of a blasting container that serves to blast workpieces with a blasting medium. The blasting container can in particular be configured as a blasting drum composed of metal that is open at one side, wherein the wall 10 can have a circular or polygonal contour. The wall 10 has an inner side 12 directed into the interior of the blasting container and an outer side 14 pointing in the opposite direction. Furthermore, the wall 10 has a plurality of openings 16 that are provided for an exit of blasting medium from the interior of the container. Only a first opening is shown in FIG. 1. However, it is understood that the wall 10 has a plurality of such openings 16.

[0037] As FIG. 1 further illustrates, a cover 18 is arranged at the outer side 14 of the wall 10 above the opening 16, but is spaced apart from the wall 10 so that a passage 20 for blasting medium is formed between the cover 18 and the opening 16 covered by said cover 18. In this respect, the cover 18 completely covers the opening 16 and the area of the cover 18 is furthermore larger than the area of the opening 16. In the embodiment example shown, the cover 18 is planar in the region of the opening and also beyond.

[0038] The geometry of the outer contour of the opening 16 and the cover 18 can in principle be arbitrary, wherein both outer contours can also be the same, for example, circular, oval, triangular, polygonal or irregular.

[0039] In the embodiment example shown in FIG. 1, the cover 18 is fastened to the outer side 14 of the wall 10 via spacers 22. The fastening can generally take place using screws, rivets, a single-piece connection or also a bonded connection.

[0040] According to a further embodiment, not shown, the cover 18 can also be part of an outer wall that has further openings for a discharge of blasting medium between the covers and offset from the openings 16 of the wall 10.

[0041] FIG. 2 shows different design options of the cover 18 and the marginal regions of the opening 16 in a highly schematic and simplified manner.

[0042] In the embodiment shown in FIG. 2a), the margin of the cover 18 is bent over downwardly in the direction of the outer side 14 of the wall 10. This is likewise the case in the embodiment according to FIG. 2b), wherein, in this embodiment, the margin of the opening 16 is additionally bent over in the direction of the cover 18 to form a kind of labyrinth seal through which blasting medium can indeed exit to a sufficient degree, but no workpieces can move outwardly.

[0043] In the embodiment according to FIG. 2c), the margin of the opening 16 is likewise bent over towards the outer side. However, in this embodiment example, the cover 18 is configured as a planar element.

[0044] In the embodiment according to FIG. 2d), similar to the variant according to FIG. 2b), the margin of the opening 16 is bent over in the direction of the cover 18 and the margin of the cover 18 is bent over in the direction of the wall 10. However, the margins in this embodiment are obliquely angled, whereas the margins in the embodiment according to FIG. 2b) are uniformly curved.

[0045] FIG. 2e) shows a variant in which the cover 18 is provided with elevations in the form of ribs or pins 24, which are located above the opening 16, at its side facing the opening 16.

[0046] In the embodiment variant shown in FIG. 2f), the wall 10 is planar in the region of the opening 16. However, a convex dome 26 is provided at the cover 18 in the region of the opening 16.

[0047] In the embodiment according to FIG. 2g), the wall 10 is again planar in the region of the opening 16. However, the cover 18 has the shape of a corrugated metal sheet.

[0048] Finally, in the embodiment according to FIG. 2h), a plurality of pins 28 are attached to the cover 18 and are located above the opening 16. Otherwise, the cover 18 and the wall 10 are planar.

[0049] FIG. 3 purely schematically shows a workpiece 30 that extends partly through the opening 16 in the wall 10 and that contacts the cover 18 with its one end (the left one in FIG. 3). In FIG. 3, the maximum clear width of the opening 16 is designated as W.sub.max. In the embodiment example shown, the maximum dimension L.sub.max of the workpiece 30 extends in the longitudinal direction and the minimum dimension L.sub.min of the workpiece 30 extends perpendicular thereto and also in the drawing plane. It is therefore a rod-shaped or pin-shaped workpiece, for example, scissors, parts of scissors, surgical instruments or the like.

[0050] The maximum clear width D.sub.max of the passage 20 is likewise shown in FIG. 3. The maximum dimension L.sub.max of the workpiece 30 is greater than the maximum clear width W.sub.max of the opening 16.

[0051] Furthermore, it can be advantageous if the maximum clear width of the passage 20 is approximately 3 to 5 times as large as the maximum dimension S.sub.max (not shown in the Figure) of the blasting medium. It is hereby ensured that the blasting medium can flow through the passage 20 with a sufficient flow rate.

[0052] FIG. 3 further illustrates that there is a critical length for the workpiece 30 (shown as a dashed line in FIG. 3) at which the workpiece 30 could fall completely into the gap between the wall 10 and the cover 18 and could thus exit from the blasting container. However, it has been found that this does not occur if the maximum dimension L.sub.max of the workpieces 30 is greater than or equal to the product of the maximum clear width D.sub.max of the passage 20 and the maximum clear width W.sub.max of the opening 16, divided by the minimum dimension L.sub.min of the workpiece 30. It can be advantageous here if the maximum dimension L.sub.max of the workpieces is selected to be somewhat larger, for example 10-15% larger, in order to reliably prevent a jamming of the workpieces in the position shown in FIG. 3.

[0053] A blasting container of the kind described above can be used in a blasting system that is provided with a blasting device for applying blasting medium to workpieces located in the blasting container. For this purpose, a rotation drive can be provided for the blasting container in order to rotate it during the blasting. The blasting container can be provided with an inlet opening and an outlet opening that can be optionally closable.

[0054] FIG. 4 shows a perspective view of an embodiment example of such a blasting container 50 whose circumferential wall 10 in turn has an inner side 12 and an outer side 14. In the embodiment example shown, the circumferential wall is not purely circular cylindrical, but is composed of different planar segments that extend in the circumferential direction and also in the radial direction. In the embodiment example shown, the segments of the circumferential wall that are oriented in the circumferential direction are provided with rectangular recesses into each of which an insert 52 is inserted that forms the wall in the region of the recesses.

[0055] The insert 52 with its individual components is shown in more detail in FIGS. 6 to 8. As is in particular illustrated in FIG. 7, the insert 52 has a plate 54, for example a rectangular plate, that is provided with a plurality of rectangular openings 16 arranged parallel next to one another. In the region of the recess, the front side or inner side of the plates 54 thus forms the wall 10. Rear webs 56 are fastened to the rear side of the plate 54 at both sides of each opening 16, wherein, between a respective two adjacent webs, a rectangular cover 18 is fastened whose two outer ends are obliquely angled (cf. in this respect also FIG. 5). This arrangement approximately corresponds to that of FIG. 2a). In this respect, the arrangement is such that a respective passage 20 (cf. in this respect FIG. 5) for blasting medium is formed between each cover 18 and the opening 16 covered by it in the region of the angled ends of the cover 18.

[0056] For an assembly of the insert 52, the plate 54 prepared in this way is fastened to an L-shaped support 58. A spacer 60 provided with flow openings can furthermore be arranged between the support 58 and the plate 54.

[0057] The shorter leg of the support 58 can be occupied by a cover plate 62. Said cover plate 62 can also be designed as a sieve plate, wherein corresponding recesses, into which the shorter leg of the insert 52 is inserted in a flush manner, are provided in the base of the container 50.

[0058] FIG. 5 shows a partly sectioned side view of the insert of FIG. 4 and FIG. 8. As can be seen, the cover 18, which is trapezoidal in cross-section, is fastened to the web 56 at both sides, wherein the passages 20 are formed between the plate 54 and the cover 18 in the region of the opening 16.

[0059] The container wall 12 can, in particular in the region of its radially extending segments, contain passage openings 51 for blasting fluids (e.g. gases, usually air or liquids, usually water) that either enter the drum from two-substance nozzles (gas/blasting medium or water/blasting medium) or are taken along as air from the environment, e.g. by blasting medium exiting at a high speed from blasting wheels. These blasting fluids accumulate on the surfaces and have to be discharged from the drum in order not to adversely influence the blasting process.