Method for cyclically screening a working chamber opening and a screening device for carrying out the method

Abstract

A method and apparatus for cyclically shielding a work chamber opening (25) when loading and unloading workpieces using a conveyor device (10) that passes through the work chamber opening. A first shielding element (21) is placed at a workpiece loading station (11.1), and a second shielding element (22) is placed behind a second workpiece placement location (11.2), as viewed in the conveying direction. When the first workpiece is loaded into the work chamber (20), the first shielding element (21) is placed at or in the work chamber opening (25) by advancing the conveyor device (10). The first shielding element (21) is then removed from the work chamber opening (25) and placed behind the second shielding element (22). These steps are repeated with subsequent workpiece placement locations (11.2, 11.3, . . . ) of the conveyor device (10) and with respective cross-over changes of the shielding elements (21, 22).

Claims

1. A method for cyclically shielding an inlet opening in a work chamber when loading workpieces into said chamber using a conveyor device having a succession of workpiece placement locations that cyclically move through a workpiece loading station located outside of said chamber adjacent said opening and thereafter pass through the work chamber, said method comprising the following steps: (a) placing a first workpiece on a workpiece placement location of the conveyor device at the workpiece loading station; (b) placing a first shielding element on the conveyor device in front of the first workpiece placed thereon, as viewed in the conveying direction; (c) placing a second shielding element on the conveyor device behind the first workpiece placed thereon, as viewed in the conveying direction; (d) loading the first workpiece that was placed on the conveyor into the work chamber and placing the second shielding element at the work chamber opening by advancing the conveyor device; (e) placing a second workpiece on a workpiece placement location of the conveyor device at the workpiece loading station; (f) removing the first shielding element from the conveyor device and placing the same on the conveyor device behind the second workpiece that was placed thereon, as viewed in the conveying direction, by using a transporting device; and (g) repeating steps (d) (e) and (f) with successive workpiece placements on the conveyor device at the workpiece loading station and with respective cross-over changes of the shielding elements.

2. A method as in claim 1, wherein the shielding elements are positioned between the workpiece placement locations and the workpieces placed there.

3. A method as in claim 1, wherein container-shaped shielding elements are used that are positioned on the workpiece placement locations and are put over the workpieces placed there.

4. A method as in claim 1, wherein the shielding elements are set onto the conveyor device.

5. A method as in claim 1, wherein the shielding elements are inserted into the upper side of the conveyor device.

6. A method as in claim 1, wherein a continuous conveyor device is used that leads into a first work chamber through a first work chamber opening and leads out of it at a second work chamber opening.

7. A method as in claim 6, wherein a rotating satellite table is used as the conveyor device, where the workpiece placement locations are arranged in a circular, ring-shaped area.

8. A method for cyclically shielding an outlet opening in a work chamber when unloading workpieces from said chamber using a conveyor device having a succession of workpiece placement locations that cyclically pass through the chamber and thereafter move past a workpiece unloading station located outside of said adjacent said opening, said method comprising the following steps: (a) placing a first shielding element on the conveyor device at the work chamber opening; (b) one moving a workpiece that is positioned on a first workpiece placement location of the conveyor device through the work chamber opening, and advancing the first shielding element, by advancing the conveyor device; (c) placing a second shielding element on the conveyor device at the work chamber opening behind the first shielding element, as viewed in the conveying direction, and behind the first workpiece placement location using a transporting device; (d) removing the workpiece from the conveyor device at the workpiece unloading station; and repeating steps (b), (c) and (d) with regard to the additional, successive workpiece placement locations and with cross-over changes of the shielding elements.

9. A method as in claim 8, wherein the shielding elements are positioned between the workpiece placement locations and the workpieces placed there.

10. A method as in claim 8, wherein container-shaped shielding elements are used that are positioned on the workpiece placement locations and are put over the workpieces placed there.

11. A method as in claim 8, wherein the shielding elements are set onto the conveyor device.

12. A method as in claim 8, wherein the shielding elements are inserted into the upper side of the conveyor device.

13. A method as in claim 8, wherein a continuous conveyor device is used that leads into a first work chamber through a first work chamber opening and leads out of it at a second work chamber opening.

14. A method as in claim 13, wherein a rotating satellite table is used as the conveyor device, where the workpiece placement locations are arranged in a circular, ring-shaped area.

15. A work chamber for blasting treatment of workpieces comprising: at least one blasting agent source disposed in the interior of the work chamber for blasting workpieces with abrasive or surface-compacting particles; an inlet gate having an inlet opening and a first and a second shielding device, each shielding device having at least one deflector surface; an outlet gate having an on open in and a first and a second shielding device, each shielding device having at least one deflector surface; a convey device extending through the inlet and outlet gates of the work chamber and having multiple workpiece placement locations, where at least one receptacle is provided for each of the shielding elements; and a transporting device arranged in each of said inlet gate and in said outlet gate, each transporting device having a lifting device for raising and lowering a gripping device configured to receive the shielding elements and a transfer device for moving the lifting device along the conveyor device; wherein each transporting device is operative to place the shielding devices in the respective inlet and outlet opening, such that the direct trajectory of the particles from the blasting agent source is intercepted by the deflector surfaces.

16. A work chamber as in claim 15, wherein the shielding elements have at least one pin at their bottom side that can be inserted into a receptacle in the upper side of the conveyor device.

17. A work chamber as in claim 15, wherein the shielding elements each have at their upper side at least one catch element, on which at least one coupling element is arranged.

18. A work chamber as in claim 17, wherein the catch element is designed in the shape of a bar and extends through a stationary sliding guide.

19. A work chamber as in claim 18, wherein the sliding guide has an H-shaped design with two cross-slots oriented perpendicular to the conveying direction into which the shielding elements can be moved and with a longitudinal slot that leads into the cross-slots and in which the catch element can travel.

20. A work chamber as in claim 17, wherein the coupling element has a prismatic design at its upper side and wherein the gripping device has a catch element that is compatible thereto.

21. A work chamber as in claim 17, wherein the coupling element is rounded at its bottom side and wherein the gripping device has concave claws.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a shielding device according to a preferred embodiment of the present invention.

(2) FIG. 2 is a first perspective view of parts of a shielding device of FIG. 1.

(3) FIG. 3 is a second perspective view of parts of a shielding device of FIG. 1.

(4) FIG. 4 is a perspective view of a shielding element shown in FIG. 3.

(5) FIGS. 5a-5d are schematic diagrams, viewed on the top, of the shielding device according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The preferred embodiments of the present invention will now be described with reference to FIGS. 1-5d of the drawings. Identical elements in the various figures are designated with the same reference numerals.

(7) FIG. 1 shows a shielding device 100 in the left area of a work chamber 20. It comprises an additional gate 23 that is placed in front of the actual work chamber opening, which is not visible here. The latter comprises a gate opening 24 that allows unrestricted access to the workpieces placed on the conveyor device 10.

(8) Behind the wall 20, visible in FIG. 1, in the upper right area of the figure is the actual working chamber, while the area at the lower edge of the image is freely accessible. There, several workpiece placement locations 11.1 are freely accessible at a conveyor device, such that workpieces can be prepared there.

(9) Another shielding device is designed in mirror image and is placed in the right area in the position of the work chamber shown in FIG. 1.

(10) A conveyor device 10 is designed as a rotating satellite table, as is essentially known, and has a plurality of workpiece placement locations 11.1, 11.2, . . . , 11.m (cf. FIG. 2) in an outer area that has the shape of a circular ring. The top side has a planar design and moves directly along the lower edge of the working chamber's 20 wall. Blasting agent that enters through the openings in the conveyor device 10 is caught in the lower area and removed from the working chamber.

(11) The actual shielding device 100 essentially comprises two plate-shaped shielding elements 21, 22 and a transporting device for the transfer thereof.

(12) The transporting device is subdivided into a lifting device 30 and a transfer device.

(13) At their top side, the shielding elements 21, 22 each have at least one bar-shaped catch element 21.2, 22.2, where at least one coupling element 21.1, 22.1 is located. At their bottom side, they each have at least one pin 21.3, 22.3 that can be inserted into a receiving recess in the conveyor device 10.

(14) The lifting device 30 comprises a linear drive or a pneumatic cylinder that is suspended at a portal 31. If can be used to raise or lower a gripping device 32. The gripping device 32 opens and closes a claw-like gripper 33 with which the coupling element 21.1, 22.1 can be gripped at the end of the catch element 21.2, 22.2.

(15) The transfer device comprises an arc-shaped guide rail 35 and a drive 34 with motor and gears. A slide carriage on which the entire lifting device 30 is mounted is supported by the guide rail 35. In this manner, the lifting device 30 can be moved parallel to the circular arc shaped direction of movement of the shielding elements 21, 22 that are placed on the conveyor device 10.

(16) FIG. 2 shows parts of the shielding device 100 in a radial viewing direction from the inside of the working chamber, wherein significant parts of the casing are not shown. Visible from the work chamber are only parts of the additional gate 23 with the gate opening 24 on the left and a work chamber wall 20 with a work chamber opening 25.

(17) The conveyor device 10 rotates under these shieldings. At its top side, it is divided into several segments that form the individual workpiece placement locations 11.1, 11.2, . . . , 11.m. The mounting devices for the workpieces vary depending on the type of workpiece and are not shown here.

(18) In FIG. 2, a first shielding element 21 is inserted between the workpiece placement locations 11.1, 11.2. Its bar-shaped catch element extends upward though a stationary sliding guide 36. A second shielding element 22 has been gripped using gripper 33 and has been raised by the lifting device 30. The transfer device has moved the lifting device 30 on the guide rail 35 to the left, counter to the conveying direction, which is indicated by the arrows. There, the lifting device 30 is now ready to lower the second shielding element 22 through the sliding guide 36 down to the rotating table.

(19) The sliding guide 36 has an H-shaped design with two cross-slots oriented perpendicular to the conveying direction and the shielding elements 21, 22 can be moved in and out through it, and it has a longitudinal slot that leads into the cross-slots and through which the catch element 21.2, 22.2 can be moved in the conveying direction.

(20) FIG. 3 shows a perspective view of the essential parts of the shielding device 100 in the same position as in FIGS. 1 and 2 from the outside bottom.

(21) Clearly visible are the pins 21.3, which extend from the bottom side of the shielding element 21 towards, where they are inserted in recesses in the conveyor device 10. Through this formfitting connection, the shielding elements are arranged at the conveyor device 10 and can be taken to the next position with the respective cyclical movement of the conveyor device 10.

(22) As can be recognized in particular in FIG. 4, the catch element 21.2 ends at the top side in a coupling element 21.1 that has a prismatic design at the top and thus has an edge that points upwards. A receiving element 34 at the gripping device is designed compatible thereto. The coupling element 21.1 is rounded at the bottom side and the gripping device has arc-shaped claws that at the right and left reach past the catch element under the coupling element 21.1.

(23) The result of the described design is that the entire shielding element is centered relative to the gripping element when the claws 33 are closed. Initially, the rounded claws 33 slide over the rounded bottom side of the coupling element 21.1 and at the same time draw the upper prismatic area into the receiving element 34 such that a form-fitting fixing is achieved in multiple directions.

(24) A shielding element 21 that may be askew relative to the horizontal direction of the conveyor device's 10 movement due to the large clearance between the pin 21.3 and the recesses in the conveyor device 10, where the pins 21.3 are inserted, is thus returned to a defined position when gripped.

(25) The sequence of movement in the method according to the invention is explained in greater detail based on the following FIGS. 5a to 5d.

(26) Each one shows shielding devices 100 at a closed work chamber 20. Here the conveyor device's 10 direction of rotation is clockwise such that loading occurs at a work chamber opening 25 in the left image area and unloading at a work chamber opening 27 in the right image area. The lower image area is outside the work chamber 20. There, some workpiece placement locations 11.1 . . . 11.5 are freely accessible for loading and unloading of workpieces 201 . . . 204.

(27) FIG. 5a shows a situation in which already two workpieces 203, 204 are located inside the work chamber 20. Two workpieces 201, 202 are placed on the conveyor device 10 outside of the work chamber 20 at workpiece placement locations 11.1, 11.2. In the previous production step, the work chamber opening 25 was closed by a first shielding element 21, which has now been raised, as indicated by the dashed presentation of the line that symbolizes the shielding element 21. A second shielding element 22 is placed behind it, in the clockwise conveying direction.

(28) As soon as the conveyor device 10 is rotated by another angle step in clockwise direction, the second shielding element 22 arrives according to FIG. 5b at or in the work chamber opening 25.

(29) The first workpiece placement location 11.1 with the first workpiece 201 is now located in the gate between the work chamber opening 25 and the opening 27 in the enter cover of the gate.

(30) Between the first workpiece placement location 11.1 and the second workpiece placement location 11.2, the other shielding element 21 is already inserted into the conveyor device 10. However, it could also still remain in a raised position above.

(31) Still in the situation according to FIG. 5b, the workpiece 204 has arrived at the unloading side in the gate between openings 27 and 26. The workpiece 203 is still located inside the work chamber 20.

(32) The work chamber opening 27 for unloading is closed by a shielding element 22. The other shielding element 21 is located outside the work chamber 20 and can already be raised.

(33) FIG. 5c shows the next step of the sequence. The conveyor device 10 is still unchanged, such that the position of the workpieces 201 . . . 204 is also still unchanged. The shielding element 22 located at the work chamber 25 is raised and transitioned to the position after the next one according to the direction of the arrows drawn in the inner circle counter to the rotating direction of the conveyor device 10. The conveyor device 10 is then rotated by one angle step as indicated by the arrow at the outer side.

(34) The position shown in FIG. 5d is then reached. The workpiece 201 is now located inside the work chamber 20 at the loading side. The work chamber opening 25 is covered by the shielding element 21. The other shielding element 22 is located behind the second workpiece 202 in standby.

(35) At the unloading side, the workpiece 204 has now fully exited the work chamber 20 and also the gate behind the work chamber opening 27. At the same time, the shielding element 22 has been transported with the conveyor device. For the cross-over change, the other shielding element 21 has been placed from the position according to FIG. 2c to the work chamber opening 27.

(36) The cycle of changing the shielding elements 21, 22 at the loading and unloading side according to FIG. 5b to 5d is repeated with the other work pieces that are positioned at the subsequent workpiece placement locations 11.3.

(37) There has thus been shown and described a novel method for cyclically screening a working chamber opening, and a screening device for carrying out the method, which fulfill all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.