Machine Tool For Dental Purposes And System Comprising Machine Tool And Workpiece

Abstract

The invention relates to a machine tool, in particular a milling machine for dental purposes, with a workpiece magazine for receiving workpieces, optionally with the aid of a housing. The workpiece magazine (22) is also moveably mounted with respect to the machine tool (10) and has a fitting position (30) for fitting a new workpiece (18) in the magazine (22). The machine tool also has a housing (40), in particular a partial housing, for each workpiece (18), the housing at least partially receiving the workpiece (18), and/or has a lifting platform (32), which is arranged adjacent to the fitting position (30) and on which the housing (40) together with the workpiece (18) can be received and displaced. The invention also relates to a system comprising a machine tool and a workpiece.

Claims

1. A machine tool comprising a workpiece magazine for receiving workpieces, optionally with the aid of a housing, wherein the workpiece magazine (22) is movably mounted with respect to the machine tool (10) and has a loading position (30) for loading a new workpiece (18) into the magazine (22), wherein the housing (40) is provided for each workpiece (18), which housing at least partially accommodates the workpiece (18), and/or wherein a lifting platform (32), is arranged adjacent to the loading position (30) and on or at which the housing (40) may be accommodated and moved together with the workpiece (18).

2. A machine tool comprising a tool magazine for receiving tools, optionally with the aid of a housing, wherein the tool magazine (22) is movably mounted with respect to the machine tool (10) and has a loading position (30) for loading a new tool (20) into the magazine (22), wherein the housing (94) is provided for each tool (20), which at least partially accommodates the tool (20), and/or wherein a lifting platform (32) which is arranged adjacent to the loading position (30) and on or at which the housing (94) may be accommodated and moved together with the tool (20).

3. The machine tool according to claim 1, wherein the lifting platform (32) is substantially vertically movable and is movable transversely to the direction of movement of the magazine (22), which is configured as a linear magazine, a circular or semicircular round magazine.

4. The machine tool according to claim 1, wherein the lifting platform (32) comprises a grip handle (62) for the manual movement of the lifting platform (32) substantially vertically, or a drive for the mechanical movement substantially vertically and/or wherein the lifting platform (32) comprises a vertical sliding guide (66) extending parallel to an axis of rotation of the workpiece magazine (22),

5. The machine tool according to claim 1, wherein, the workpiece (18) is a dental workpiece which is a blank and is taken out as a dental restoration from the machine tool (10) via the same loading position (30) in the magazine (22) and via the lifting platform (32) and/or wherein a tool (20) is provided as a dental tool comprising a milling tool, a grinding tool, or a rotary grinding tool which is loaded to a tool spindle (14) via the magazine (22) and via a robot arm (16) and is taken out from the machine tool (10) for tool changing via the loading position (30) in the magazine (22) and via the lifting platform (32) of the machine tool (10).

6. The machine tool according to claim 1, wherein the workpiece magazine (22) is simultaneously designed as a tool magazine which, at predetermined rotational positions, accommodates workpieces (18) with associated housings (40) and, at other rotational positions, tools (20), via receiving housings (94).

7. The machine tool according to claim 1, wherein at each rotational position of the magazine (22) at least one holding element (44, 46) is formed for a latchable accommodation of a housing (40, 94).

8. The machine tool according to claim 7, wherein each housing (40, 94), on a side of the housing (40, 94) facing the receiving position of the magazine (22), has at least one latching tongue (84, 86) for engaging in a retaining element (44, 46) connected to the magazine (22), the side of the housing being the upper side of the housing (40, 94).

9. The machine tool according to claim 1, wherein each workpiece (18) and/or one or more tools (20) has a groove or recess (80) having a the dimension which is adapted to projections of the housing (40) and into which groove or recess (80) projections of the housing (40) can be inserted.

10. The machine tool according to claim 9, wherein, for mounting the workpiece (18) and/or the tool (20) in the housing (40) at a lower end of the housing, latching tongues (84, 86) are formed on the projections, which latching tongues at least partially encompass a holder (82) of the workpiece (18) and/or the tool (20), in the groove thereof.

11. The machine tool according to claim 1, wherein a part of the workpiece (18) and/or a part of a tool (20), protrude from the housing (40), and wherein the grooves are formed on a collar (82, 86) of the workpiece and/or tool.

12. The machine tool according to claim 11, wherein, in a transfer position of the workpiece magazine (22), the collar (82, 86) projects from the housing (40) such that it can be grasped by a robot arm (16) of the machine tool (10).

13. The machine tool according to claim 1, wherein the workpiece (18) and/or a tool (20) is slidably mounted in the housing (40), and can be taken out manually or via a robot arm (16) by lateral displacement.

14. The machine tool according to claim 1, wherein the magazine (22) is arranged at a top of the machine tool (10) and opposite a milling spindle (14), and/or wherein the housings (40, 94) comprises latching tongues (84, 86) and are suspended on holding elements (44, 46) of the magazine (22).

15. The machine tool according to claim 1, wherein, when the lifting platform (32) is raised into the loading position (30), the housing (40, 94) placed on the lifting platform (32) remains suspended on the respective holding element (44, 46) of the magazine (22) when the at least one latching tongue (84, 86) thereof latches in place, even if the lifting platform (32) is lowered.

16. The machine tool according to claim 1, wherein a holder (82) of the workpiece (18) and/or a working tip of a tool (20) is suspended from the housing (40, 94) and is accommodated in a recess (80) of the lifting platform (32) when the housing (40) including the workpiece (18) is placed on the lifting platform (32).

17. The machine tool according to claim 1, wherein the housing (40, 94) encompasses the workpiece (18) and/or a tool (20) so far that it can be taken out from the lifting platform (32) only together with the housing (40).

18. The machine tool according to claim 1, wherein two mutually opposite side walls of the housing (40) are provided, which flatly extend and on which the housing (40) may be grasped, and wherein the housing (40) encompasses the workpiece (18) such that the workpiece (18) is protected with respect to a ceramic portion thereof.

19. A system comprising a machine tool and a workpiece comprising a workpiece magazine for receiving workpieces optionally with the aid of a housing, wherein the workpiece magazine (22) is movably mounted with respect to the machine tool (10) and has a loading position (30) for loading a new workpiece (18) into the magazine (22), wherein a housing (40) is provided for each workpiece (18), which housing at least partially accommodates the workpiece (18), and/or wherein a lifting platform (32) is arranged adjacent to the loading position (30) and on or at which the housing (40) may be accommodated and moved together with the workpiece (18).

20. The system according to claim 19, wherein the workpiece (18) comprises a dental material which can be milled or ground or machined.

21. The machine tool according to claim 1, wherein the machine tool is a milling machine for dental purposes, and wherein the housing (40) comprises a partial housing for each workpiece (18).

22. The machine tool according to claim 2, wherein the machine tool is a milling machine for dental purposes, and wherein the housing (40) comprises a partial housing for each tool (20).

Description

[0082] Further advantages, details and features will arise from the following illustration of the invention using several examplary embodiments, while reference is made to the drawings, wherein:

[0083] FIG. 1 is a sectional schematic lateral view of a machine tool according to the invention, with partial representation of the workpiece magazine;

[0084] FIG. 2 is a perspective lateral view of a portion of the workpiece magazine;

[0085] FIG. 3 is a view of a lifting platform according to the invention with workpiece and workpiece housing being inserted;

[0086] FIG. 4 is a view of another embodiment of the lifting platform with workpiece and workpiece housing being inserted;

[0087] FIG. 5 is a view of the lifting platform according to FIG. 4 from the rear;

[0088] FIG. 6a is a perspective view of a workpiece housing;

[0089] FIG. 6b is the workpiece housing of FIG. 6a, but from a different perspective;

[0090] FIG. 6c is the workpiece housing of FIG. 6b with workpiece being inserted;

[0091] FIG. 6d is detail views of FIG. 6c;

[0092] FIG. 7a is a perspective view of a tool housing;

[0093] FIG. 7b is a detailed view of FIG. 7a with tool being inserted;

[0094] FIG. 8 is a schematic cross-sectional view of another embodiment of a lifting platform according to the invention;

[0095] FIG. 9 is a perspective view of another embodiment of a housing for a workpiece according to the invention; and

[0096] FIG. 10 is a perspective view of another embodiment of a housing for a tool according to the invention.

[0097] FIG. 1 shows an embodiment of a machine tool 10 according to invention. In the example shown, the machine tool is designed as a milling machine for dental purposes. It is to be understood that the invention may also be used with any other cutting machine tool, especially compact machine tools, such as grinding machines or turning-grinding machines for the dental industry.

[0098] The machine tool 10 comprises a milling chamber 12 in which a tool spindle 14 is operated driven by a spindle motor. A robot arm 16 is capable of feeding a workpiece 18 to the spindle 14 in a suitable manner, wherein the robot arm 16 is mounted in a 5-axis manner and the tool spindle 14 is fixed.

[0099] The tool spindle 14 accommodates a tool 20, holding it in its clamping jaws in a manner known per se.

[0100] The tool spindle 14 is mounted at the bottom of the milling chamber 12. Opposite the spindle 14, i.e. on the ceiling of the milling chamber 12, a workpiece magazine 22 is mounted. The workpiece magazine 22 extends above the milling chamber 12 and is separated therefrom by the ceiling wall which is not shown. A workpiece may be taken out from or inserted into the magazine 22 at a transfer position 26 of the workpiece magazine 22 through a door 24.

[0101] The workpiece magazine 22 is approximately quarter-circular and pivotably mounted, such that any workpiece may be brought into the transfer position 26. In addition, it also accommodates tools 20 between the workpieces 18.

[0102] A loading position 30 is also provided, and is provided not directly above the milling chamber 16, but is laterally offset. The loading position 30 allows workpieces and tools to be fed to magazine 22 in the blank state and allows finished workpieces to be taken out therefrom.

[0103] A lifting platform 32 is provided below the loading position 30. This is for taking out the tool or workpiece in the lower position of the lifting platform 32.

[0104] The lifting platform 32 is movably mounted in a vestibule 34. This is separated from the milling chamber 12 by a partition wall 36.

[0105] A detail of the machine tool 10 is shown in FIG. 2. It is the transfer position 26 of the workpiece magazine 22. As can be seen, for example, a workpiece is held in a housing 40, i.e. a workpiece housing, and mounted on a lever 42. For this purpose, the lever 42 has holding elements 44 and 46, which are described in detail below. The lever 42 is pivotably mounted on an axle 48. It is pulled into an upper position 52 by a tension spring 50.

[0106] Several levers 42 are shown behind the lever 42, as shown herein, and are shown in the upper position.

[0107] zo The lever 42 in the transfer position 26 is swiveled downwards by an actuating element 54 acting against the effect of the spring 50.

[0108] Preferably, the lever is swiveled so far that the lever 42 extends essentially horizontally.

[0109] In this position, the housing 40 can easily be taken out with the workpiece 18 held therein.

[0110] In the upper position, in which the levers 42 extend obliquely upwards at an angle of about 45 and in which the actuating element 54 is not active, the workpiece magazine 22 can be rotated freely. Contrary to this, the rotating position of the workpiece magazine 22 is fixed when a lever 42and thus the associated housing 40 including the workpiece 18is to be lowered in the transfer position 26. For this purpose, the actuating element 54 is activated and the workpiece with the housing 40 is lowered so that the robot arm 16 can grasp it more easily.

[0111] A corresponding embodiment including an actuating element 54 is also provided for the loading position 60 schematically shown in FIG. 3; an actuating element is also arranged herein, even if this may not be seen from FIG. 3.

[0112] The loading position 60 is located above the vestibule 34. The lifting platform 32 is arranged at this position, namely in a vertically movable manner. In the state shown in

[0113] FIG. 3, the lifting platform 32 carries a housing 40, which is loaded with a workpiece 18. For details concerning the embodiment of the housing 40, reference is to be made to FIGS. 6a to 6d.

[0114] The lifting platform 32 has a grip handle 62 which extends, like a bow, essentially horizontally and transversely at the front, i.e. at the front of the vestibule 34. Manual operation moves the lifting platform 32 from the lower position shown in FIG. 3 to an upper position. In the upper position the lifting platform 32 is close to the loading position 60 of the workpiece magazine 22. The housing 40, on its upper side, has a web 64 zo extending from the rear to the front, on which latching tongues are formed, as shown in

[0115] FIG. 6a. These locking tongues are suitable for latching into the holding elements 44 of the workpiece magazine 22, and holding the housing 40 together with the workpiece 18 as soon as the lifting platform 32 is brought into the upper position via the gripping handle 62.

[0116] To move the workpiece 18 into the milling chamber 12, the associated lever 42 is now lifted in the loading position by the effect of the spring 50 by releasing the actuating element 54. The respective workpiece in the housing 40 is then swiveled by the workpiece magazine 22 into the transfer position 26, where it is lowered again so that the robot arm 16 can grasp a downward protruding holder of the workpiece and take out the workpiece from the housing 40.

[0117] After finishing, the workpiece is transported in the reverse direction, with the lever 42 of the workpiece magazine 22 being lowered and raised accordingly.

[0118] The lifting platform 32 can also be lowered in the meantime in order to allow another workpiece accommodated in a housing to be fed into the workpiece magazine 22.

[0119] In FIG. 4 the vestibule 34 is shown in a perspective different from that of FIG. 3. Herein, the housing 40 is not equipped with a workpiece. The lifting platform 32 is vertically guided on a sliding guide 66.

[0120] A rear view of the vestibule 34 is shown in FIG. 5. The sliding guide 66 has a slot 68 which extends vertically on the rear wall of the vestibule 34. This is crossed by a web which is attached to the rear of the lifting platform 32. A counter plate 70 is attached to the web and is slightly wider than the slot 68. The play of the counter plate 70 against the rear wall of the vestibule 34 is such that the lifting platform 32 is self-retaining so that it is maintained at the height as adjusted by the user.

[0121] It is to be understood that instead of the guide shown herein, any other guides are also possible, for example with an adjustable brake for adjusting the displacement force.

[0122] FIG. 6a shows a perspective view of a housing 40. The housing has closed lateral walls 72 and 74. The unit consisting of the workpiece and the housing may then be grasped easily therewith. The web 64 is equipped with two spring tongue arrangements 76, which are to encompass the holding elements 44 and 46 of the workpiece magazine.

[0123] A perspective view of the housing 40 is shown in FIG. 6b from another angle. The housing 40 has an open rear wall and a recess 80 at the bottom, which is designed to allow a holder 82 (FIG. 6c) of a workpiece 18 to pass therethrough. The recess 80 is limited by slightly resilient latching tongues 84 and 86, which project slightly inwards at the ends so that they can securely hold the holder 82.

[0124] As shown in FIG. 6c, the workpiece 18 is surrounded by the housing 40 on at least two sides when inserted. Loading is done horizontally, via the open rear wall of the housing. The holder 82 of the workpiece 18 protrudes downwards from the housing. FIG. 6d shows that the holder 82 has a groove 88 into which the latching tongues 84 and 86 may engage. With respect to the lateral walls 72 and 74, the latching tongues 84 and 86 form projections 90 facing inwards.

[0125] The holder 82 has an essentially square cross-section. However, it is provided with two inclined surfaces 92 to be unequivocally supported on the robot arm 16, which surfaces 92 extend at an angle of about 45 to the adjacent surfaces.

[0126] A housing 94 for tools is shown in FIG. 7a. This housing also has a web 64 with spring tongue arrangements 76 at the top center. Two latching switch arrangements 84 and 86 are located below, each of which serves to hold one tool 20. This is illustrated in FIG. 7b.

[0127] Tool 20 has a collar 97 between its shank 95 and its working tip 99. An upper groove 96 is formed on the collar, into which groove the latching tongue arrangement 86 engages. In addition, a lower groove 98 is provided, which can be grasped by a gripper 100 of the robot arm 16 (see FIG. 1), in order to move the tool 20 out of the position in the latching zo tongue 86 by lateral movement.

[0128] For the provision in the tool spindle 14, the robot arm 16 is turned by 180 so that the shank of tool 20 can be inserted into the chuck.

[0129] A modified embodiment of the lifting platform 32 is shown in FIG. 8. It can be seen that the holder 82 of the workpiece 18 passes through a recess 102 of the lifting platform 32 when the housing 40 including the workpiece 18 is placed thereon.

[0130] In this embodiment, a pivoting element 104 is essentially L-shaped and mounted on an axis 106 on the lifting platform 32 for the rest. This swivel element 104 ends at the bottom outside in the grip handle 62 and at the top in a grasp claw 108, which is dimensioned such that when lowering the grip handle 62 engages across the housing 40 and when lowering it also pulls the housing 40 downwards.

[0131] This allows the latching connection between spring tongue assemblies 76 and the holding elements 44 and 46 of the magazine 22 to be released to move the lifting platform 32 together with workpiece 18 from the upper position to the lower position.

[0132] Another embodiment of a workpiece housing 40 according to the invention is shown in FIG. 9. In this embodiment, holding elements to be mounted in grooves on a holder 82 of a workpiece 20 are provided as illustrated in FIG. 6b below, which holding elements end in latching tongues 84 and 86.

[0133] The difference to the embodiment of the workpiece housing 40 of FIGS. 6a to 6d is the type of suspension in the magazine 22.

[0134] A web 64 is provided, which extends across the entire upper side of the housing. The web 64 has a locking tongue 74 in the center thereof, which is for mounting to a corresponding holding element of the magazine 22.

[0135] zo At the back and front, the web 64 has two grooves 110, 112. The grooves 110 and 112 are each for engaging transverse pins at the respective position of the magazine 22. In this respect, the magazine 22 is provided with positions for the workpiece housings 40, but also with positions for the tool housings 94.

[0136] The arrangement of the grooves 110, 112 is different in these two housings, in that there is a coding.

[0137] The housings 40 and 94 are made of sheet metal and comprising stiffeners 114, increasing the precision of the guidance. Sheet metal has the advantage of having adjustable stiffness and elasticity depending on the design. It is to be understood that any other materials may also be used instead for providing a housing according to the invention; an example for this is glass-fiber reinforced plastic or realization of the housing using injection molding or die casting.

[0138] FIG. 10 shows a workpiece housing 94. According to FIG. 7a and FIG. 7b, the workpiece housing 94 has latching tongues 84 and 86 for holding a total of 2 workpieces at their collars. The mounting positions for the two tools not shown herein have height stops on their upper side, wherein one of which height stops 120 is shown in FIG. 10.