DEVICE FOR PRODUCING THREE-DIMENSIONAL MODELS WITH SPECIAL BUILDING PLATFORMS AND DRIVE SYSTEMS

Abstract

The invention relates to a device for producing three-dimensional models in a continuous process, comprising a build surface which has a first end in the direction of movement and a second end in the direction of movement, at least one dosing device and at least one solidification unit, characterized in that the build surface is designed to transport heavy components, and the components are transportable over the build surface essentially without distortion, and also comprising a method therefor.

Claims

1. A device for producing three-dimensional models, comprising: i. a build platform for receiving layers of a particulate material, wherein the build platform is a portion of a conveyor; ii. a drive unit for driving the conveyor in a conveyance direction; iii. a dosing unit over the build platform for providing the layers of the particulate material; and iv. a solidification unit over the build platform for selectively solidifying the particulate material; wherein the build platform has a first end proximate a region where the particulate material is received and a second end in the conveyance direction; wherein a distortion of the three-dimensional model during a conveyance on the conveyor is reduced by one or any combination of the following: a. the conveyor is supported by a rigid supporting surface; or b. the conveyor is a link conveyor including links having a hinge with a stop, wherein the stop causes the conveyor to be rigid and sagging is prevented between the first and second ends; or c. the conveyor includes a conveyor belt supported by spaced apart cylinders or rollers.

2. The device of claim 1, wherein the device includes the conveyor is supported by a rigid supporting surface

3. The device of claim 2, wherein the rigid support surface includes one or more sliding elements, wherein the sliding element is elongated in the conveyance direction.

4. The device of claim 3, wherein the sliding element has a plastic surface and the conveyor slides over the plastic surface.

5. The device of claim 2, wherein the conveyor is driven by a plurality of spaced apart drive rollers.

6. The device of claim 5, wherein the device includes pressing rollers that press the conveyor onto the drive rollers.

7. The device of claim 1, wherein the conveyor is a link conveyor including links having a hinge with a stop, wherein the stop causes the conveyor to be rigid and sagging is prevented between the first and second ends.

8. The device of claim 7, wherein the link conveyor includes links having a gripper element and the drive includes a linear feed with a gripper for gripping the gripper element and moving the link conveyor in the conveyance direction.

9. The device of claim 8, wherein each link includes a gripper element.

10. The device of claim 7, wherein the link conveyor includes links having a gripper element and the drive includes a worm wheel, wherein a rotation of the worm wheel moves the link conveyor in the conveyance direction.

11. The device of claim 10, wherein each link includes a gripper element.

12. The device of claim 1, wherein the conveyor includes a conveyor belt supported by spaced apart cylinders or rollers.

13. The device of claim 12, wherein the conveyor belt is driven at the same speed at spaced apart drive locations.

14. The device of claim 13, wherein the drive unit includes a driving belt.

15. The device of claim 14, wherein the driving belt is a toothed belt.

16. The device of claim 13, wherein the conveyor belt is supported by the cylinders and each of the cylinders is driven at the same speed.

17. The device of claim 13, wherein the conveyor is supported by a middle support including an air cushion.

18. The device of claim 13, wherein the conveyor is supported by a middle support including friction bearings.

19. The device of claim 13, wherein the conveyor is supported by a middle support including rollers or ball casters.

20. The device of claim 13, wherein the conveyor belt includes lateral edges, wherein the lateral edges are both positioned between spaced apart pairs of driving cylinders and cylinder bearings, wherein each driving cylinder-cylinder bearing pair independently drives the conveyor belt.

21. The device of claim 13, wherein a single motor drives each driving cylinder.

22. A method of constructing one or more three-dimensional models using the device of claim 1, comprising the steps of: i. applying layers of a particulate material on the build platform using the dosing unit; ii. selectively solidifying the particulate material using the solidification unit; and repeating the steps until the three-dimensional model is produced; wherein the build platform is a portion of a conveyor and the three-dimensional model is conveyed on the conveyor; wherein a distortion of the three-dimensional model during a conveyance on the conveyor is reduced by one or any combination of the following: a. the conveyor is supported by a rigid supporting surface; or b. the conveyor is a link conveyor including links having a hinge with a stop, wherein the stop causes the conveyor to be rigid and sagging is prevented between the first and second ends; or c. the conveyor includes a conveyor belt supported by spaced apart cylinders or rollers.

Description

DESCRIPTION OF THE FIGURES

[0108] FIG. 1 shows a preferred structure according to the invention, including a closed conveyor belt (e.g., link conveyor) (7) and an open sealing belt (6). The conveyor belt is able to bear the great weight of the particulate material cake while the cover belt is being unrolled and should only prevent the conveyor belt from coming into contact with the particulate material cake. The conveyor belt is unrolled from a roller and rolled up again behind the conveyor belt. The cover belt may be fed by means of frictional engagement on the conveyor belt or by winding up.

[0109] FIG. 2 shows a preferred link conveyor according to the invention, including hinges which permit mobility only in one direction. The link conveyor is moved by a roller track in this case. Only one, multiple or all rollers may be driven.

[0110] FIG. 3a shows a preferred transport unit according to the invention, comprising conveyor belt (7) (preferably a link conveyor as in FIG. 2), which is driven laterally by driving rollers (14) and is supported on small rollers (15) in the middle.

[0111] FIG. 3b shows a similar structure, in which conveyor belt (7) rests on continuous driving rollers (17) over its complete width. To achieve a better frictional engagement between the driving rollers (14) or driving cylinders (17) and the conveyor belt (7), pressing rollers (13) press the conveyor belt onto the driving rollers (14) or driving cylinders (17).

[0112] FIGS. 4a and 4b show a preferred structure according to the invention, in which the driving rollers (14) are driven by a shared driving belt (18). Conveyor belt (7) may then rest on the driving belt and be additionally supported. In FIG. 4a, the middle of conveyor belt (7) is supported on sliding elements (19) made of, e.g., plastic. In FIG. 4b, the middle of the conveyor belt is carried by air cushions (20).

[0113] FIGS. 5a through 5c show a structure according to the invention, comprising a link conveyor (7), which has a gripping element (22) on each link. A gripper, which repeatedly grips and positions a gripping element, passes beneath the link conveyor. The sequence is gripping and positioning (FIG. 5a), opening the gripper (FIG. 5b), returning and regripping a link (FIG. 5c).

[0114] FIG. 6 also shows a structure according to the invention, including a link conveyor (7), which has a gripping element (22) on each link, according to the invention. In this case, gripping elements (22) are positioned by a rotating worm drive (24).

[0115] FIG. 7 shows an oblique view of a preferred feed system according to the invention, including raised grates according to the invention.

[0116] FIGS. 8a through 8c show the sequence of the feed system from FIG. 7, from the front and from the side in each case, according to the invention.

[0117] FIG. 8a shows the starting position when both lifting grate (26) and thrusting grate (27) carry the conveyor belt. In FIG. 8a, lifting grate (26) has been extended and thrusting grate (27) subsequently lowered.

[0118] In FIG. 8b, lifting grate (26) has been lowered so that only thrusting grate (27) carries conveyor belt (7). Thrusting grate (27) then moves conveyor belt (7) into its next position.

[0119] In the lowered state, thrusting grate (27) returns to its starting position, as illustrated in FIG. 8a.

[0120] FIG. 9 shows a preferred structure according to the present invention with self-propelled building platforms (31). They are moved into building device (32).

[0121] FIGS. 10a through 10c show additional preferred embodiments according to the invention. In this case, the feedstock is not produced linearly but rotatorily. The process begins at a first position or end and ends at a second position or end. FIG. 10b is a view of FIG. 10a from above. FIG. 10c is a side view of FIG. 10b of the cone printer according to the invention, on sectional plane A-A. (33) designates the outwardly oriented movement of coater (1) and solidification unit (2), which is indicated using directional arrows, the method being carried out on building platform (34), and a particulate material feedstock (3) being generated and components [produced], e.g., component (5), following solidification. For this purpose, round building platform (34) is rotated, while coater (1) and the print axis move away from the rotation axis. Coater (1) is rotated 90 with respect to the other preferred devices of the invention described above and may be operated continuously. Solidification unit (2) may also work continuously, whereby a plurality of components may be produced in this manner on one building platform (34) in one operation (batch). A build cone (21) may be used to start the system. The alpha angle may be changed, depending on the particulate material, and thus be optimally adapted to the particular particulate material used. This device type requires the data for the molds for the components to be produced to be skewed not only linearly but also on the basis of polar coordinates. The dimensions of the cone printer and the building platform as well as the device as a whole may be selected in such a way that both very small and very large and heavy components may be produced without distortion.

[0122] FIG. 11 shows a preferred building device (32) according to the invention, to the end of which an unpacking area, including a roller track (35), is connected. The finished components are deposited directly onto the roller track. Loose particulate material may run off between the rollers and thus support unpacking. The roller track may be driven or it may run passively.

[0123] FIG. 12 shows a preferred building device according to the invention with a rotating building platform (34). Coater (1) and solidification unit (2) move only translatorily, while building platform (34) continues to rotate layer by layer and thus continuously builds up material feedstock (3). In another preferred embodiment, the device in FIG. 12 may be configured in such a way that it is combined with an unpacking station or an unpacking operation in an arbitrary position. Finished components (5) are shifted to a position (36) inside or outside or below or above building platform (34) and freed of the remaining loose particulate material simultaneously or in another work step. The process begins at a first position or end, e.g., at the point of the first particulate material application, and ends at a second position or end, e.g., upon completion of the component or preferably at the point of unpacking. The loose particulate material may be resupplied cyclically to the further continuous process. The particulate material supply is thus limited to the quantities which are removed from circulation in the form of components and any non-reusable quantities.

[0124] FIGS. 13a through 13f show a drive for belts or link aprons with lifting grates (26) and thrusting grates (27) according to the principle of the step conveyor. Thrusting grate (27) moves on lever arms which swivel back and forth. Lifting grate (26) is raised on the return swiveling motion.

[0125] FIGS. 14a through 14d show a drive for belts or link aprons with lifting grates (26) and thrusting grates (27) according to the principle of the step conveyor. Thrusting grate (27) moves on rotating lever arms.

[0126] FIGS. 15a through 15d show a drive for belts or link aprons with lifting grates (26) and thrusting grates (27) according to the principle of the step conveyor. A vertical lifting of lifting grate (26) alternates with an inclined lifting of thrusting grate (27).

LIST OF REFERENCE NUMERALS

[0127] 1 Coater [0128] 2 Solidification unit [0129] 3 Powder cake/particulate material feedstock [0130] 4 Tunnel wall [0131] 5 Component (being built) [0132] 6 Roller for cover belt [0133] 7 Conveyor belt (e.g., link conveyor) [0134] 8 Linear unit [0135] 9 Build space [0136] 10 Link with hinge [0137] 11 Driving cylinder [0138] 12 Cylinder bearing [0139] 13 Pressing roller [0140] 14 Driving roller [0141] 15 Bearing roller [0142] 16 Motor [0143] 17 Conveyance direction [0144] 18 Driving belt (e.g., toothed belt) [0145] 19 Sliding element [0146] 20 Air cushion [0147] 21 Gripper [0148] 22 Gripping element [0149] 23 Linear feed [0150] 24 Worm wheel [0151] 25 Frame [0152] 26 Lifting grate [0153] 27 Thrusting grate [0154] 28 Linear bearing [0155] 29 Lifting unit for lifting grate [0156] 30 Lifting unit for thrusting grate [0157] 31 Self-propelled building platform [0158] 32 Building device [0159] 33 Direction of movement of the coater and the solidification unit [0160] 34 Rotating building platform [0161] 35 Roller track [0162] 36 Unpacking area