DEVICE FOR HOLDING A WORKPIECE

Abstract

A device for holding a workpiece that includes a first clamping element and at least one second clamping element, wherein the first clamping element and the second clamping element each include on an end side extending in a radial plane a first engagement structure and at least one second engagement structure at different radial positions configured to engage at a first time an end side of a first workpiece having a first diameter and at a second time an end surface of a second workpiece of a second diameter different than the first diameter for holding the workpiece by moving the first clamping element and the second clamping element in the radial direction.

Claims

1. A device for holding a workpiece, comprising: a first clamping element; and at least one second clamping element, wherein the first clamping element and the second clamping element each include on an end side extending in a radial plane a first engagement structure and at least one second engagement structure at different radial positions configured to engage at a first time an end side of a first workpiece having a first diameter and at a second time an end surface of a second workpiece of a second diameter different than the first diameter to hold the first workpiece or the second workpiece by moving the first clamping element towards the second clamping element in the radial direction.

2. The device according to claim 1, wherein the first engagement structure comprises a first raised circular ring segment and the second engagement structure comprises a second raised circular ring segment and a groove between the first circular ring segment and the second circular ring segment.

3. The device according to claim 1, wherein a radially inwardly directed engagement contact surface of the first circular ring segment and/or of the second circular ring segment is inclined relative to a normal of the radial plane by an inner inclination angle () so that the first circular ring segment and/or the second circular ring segment projects radially inward.

4. The device according to claim 3, wherein a radially outwardly directed surface of the first circular ring segment and/or of the second circular ring segment is inclined relative to the normal of the radial plane by the inner inclination angle (), so that the radially inwardly directed engagement contact surface is substantially parallel to the radially outwardly directed surface of the respective circular ring segment.

5. The device according to claim 3, further including: an adapter attached to an end side of the workpiece, wherein the adapter includes at least one projection configured to be engaged by the first or the second engagement structure.

6. The device according to claim 5, wherein the radially inwardly directed engagement contact surface forms a sharp edge with the axially directed end side of the circular ring segment, and wherein the sharp edge is configured to engage an adapter groove base of the adapter attached to the workpiece.

7. The device according to claim 1, including a plurality of additional engagement structures equally radially spaced and configured to be brought into engagement with a plurality of projections of the adapter of workpieces of different sizes.

8. The device according to claim 2, wherein a depth of the groove is between 0.8 and 1.2, times a radial extension of the groove and is between 3 mm and 5 mm, and/or wherein a radial extension of the circular ring segment is between 0.8 and 1.2, times a radial extension of the groove, and the radial extension of the circular ring segment is between 3 mm and 5 mm.

9. The device according to claim 1, wherein the first clamping element is produced from aluminum, wherein the first engagement structure and the second engagement structure are formed by turning and/or milling, and/or wherein the first circular ring segment has radius of curvature of between 10 mm and 20 mm, and the second circular ring segment has a radius of curvature of between 100 mm and 300 mm.

10. The device according to claim 2, wherein a radially inwardly directed engagement contact surface of the first circular ring segment and/or of the second circular ring segment is inclined relative to a normal of the radial plane by an inner inclination angle () so that the first circular ring segment and/or the second circular ring segment projects radially inward, wherein a radially outwardly directed surface of the first circular ring segment and/or of the second circular ring segment is inclined relative to the normal of the radial plane by the inner inclination angle (), so that the radially inwardly directed engagement contact surface is substantially parallel to the radially outwardly directed surface of the respective circular ring segment, further including an adapter attached to an end side of the workpiece, wherein the adapter includes at least one projection configured to be engaged by the first or the second engagement structure, wherein the radially inwardly directed engagement contact surface forms a sharp edge with the axially directed end side of the circular ring segment, and wherein the sharp edge is configured to engage an adapter groove base of the adapter attached to the workpiece, wherein a depth of the groove is between 0.8 and 1.2, times a radial extension of the groove and is between 3 mm and 5 mm, wherein a radial extension of the circular ring segment is between 0.8 and 1.2, times a radial extension of the groove, and the radial extension of the circular ring segment is between 3 mm and 5 mm, and wherein the first circular ring segment has radius of curvature of between 10 mm and 20 mm, and the second circular ring segment has a radius of curvature of between 100 mm and 300 mm.

11. The device according to claim 1, wherein the first engagement structure comprises a first axially facing groove or a first axially facing projection having a first radius of curvature and the second engagement structure comprises a second axially facing groove or second axially facing projection having a second radius of curvature greater than the first radius of curvature.

12. A method for holding, for rotary machining, a first workpiece at a first time and a second workpiece at a second time, the second workpiece having a diameter at least twice as large as a diameter of the first workpiece, the method including: attaching a first adapter having an axial facing groove or an axial facing projection on the end surface of the first workpiece; providing a first clamping element and a second clamping element each having a first axially facing groove or a first axially facing projection having a first radius of curvature and a second axially facing groove or second axially facing projection having a second radius of curvature greater than the first radius of curvature; placing the axially facing groove or the axially facing projection of the first adapter into the first axially facing groove or the first axially facing projection of the first clamping element and into the first axially facing groove or first axially facing projection of the second clamping element; moving the first clamping element toward the second clamping element to clamp the first adapter; releasing the first workpiece by separating the first clamping element and the second clamping element; attaching a second adapter having an axially facing groove or an axially facing projection on the end surface of the second workpiece; placing the axially facing groove or the axial facing projection of the second adapter into the second axially facing groove or the second axially facing projection of the first clamping element and into the second axially facing groove or second axially facing projection of the second clamping element; and moving the first clamping element toward the second clamping element to clamp the second adapter.

13. The method according to claim 12, wherein the second diameter is at least ten times larger than the first diameter.

14. A device for holding a workpiece, comprising: a first clamping element having a first axially facing groove or a first axially facing projection having a first radius of curvature and a second axially facing groove or second axially facing projection having a second radius of curvature greater than the first radius of curvature; a second clamping element having a first axially facing groove or a first axially facing projection having the first radius of curvature and a second axially facing groove or second axially facing projection having the second radius of curvature; wherein the first axially facing groove or the first axially facing projection of the first clamping element and the first axially facing groove or the first axially facing projection of the second clamping element are configured to receive an axial projection or an axial groove on a first workpiece and to clamp the axial projection or the axial groove when the first clamping element and the second clamping element move radially, and wherein the second axially facing groove or the second axially facing projection of the first clamping element and the second axially facing groove or the second axially facing projection of the second clamping element are configured to receive an axial projection or an axial groove of a second workpiece having a larger diameter than a diameter of the first workpiece and to clamp the axial projection or the axial groove of the second workpiece when the first clamping element and the second clamping element move radially.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1A schematically shows an end side view of a clamping element according to an embodiment of the present disclosure.

[0019] FIG. 1B schematically illustrates a side view along the line B-B in FIG. 1A of the clamping element according to an embodiment of the present disclosure.

[0020] FIG. 1C illustrates a detailed view of FIG. 1B.

[0021] FIG. 1D illustrates a plan view of the clamping element illustrated in FIG. 1A.

[0022] FIG. 1E illustrates a further side view of the clamping element illustrated in FIG. 1A.

[0023] FIG. 1F illustrates a rear view of the clamping element illustrated in FIG. 1A.

[0024] FIG. 2 illustrates a schematic perspective view of the clamping element illustrated in FIG. 1A, wherein the end side is shown.

[0025] FIG. 3 illustrates a clamping element set comprised of three clamping elements, as is illustrated in FIG. 1A, in a side view.

[0026] FIG. 4 illustrates a device for holding a workpiece according to an embodiment of the present disclosure, which carries out a method step of a method for holding various work pieces according to embodiments of the disclosure.

DETAILED DESCRIPTION

[0027] FIG. 1A illustrates a clamping element 1 of a device for holding a workpiece according to an embodiment of the present disclosure, along an axial direction 3, corresponding to an end view, wherein the axial direction 3 is perpendicular to a radial direction 5. Thus in FIG. 1A the end side of the clamping element 1 is illustrated. On the end side extending in the radial plane the clamping element 1 includes at least one engagement structure 7 and at least one second engagement structure 9 at different radial positions r1, r2, r3, . . . rn. With these engagement structures an end side of a workpiece, or an adapter attached to the end side of the workpiece, can be brought into engagement when the clamping element 1 together with two other clamping elements (see, for example, FIG. 3) are moved radially inward toward one another.

[0028] The clamping element 1 further includes two through-holes 11, which can be used for attaching the clamping element 1, for example, to a guide rail. In the example of FIG. 1A the radius of the clamping element 1 is 100 mm. However, the radius can also be larger, for example, 200 mm or 150 mm or 300 mm. Depending on the sizes of workpieces which are to be held using the clamping element 1, the radius can be correspondingly adapted.

[0029] FIG. 1B is a side view of the clamping element 1 of FIG. 1A along the line B-B. Here it can be seen that the engagement structures 7 and 9 each forms circular ring segments, which are raised, so that they project in a tooth-shaped manner. As can be seen in the detail view 13 in FIG. 1C, a groove 15 is formed between the circular ring segments 7, 9, at which material has been removed. The groove 15 is inclined by an inner inclination angle with respect to a normal 17 of the end side 19 of the clamping element 1. In particular a radially inwardly directed engagement contact surface 21 of the circular ring segment 9 is inclined by the inner inclination angle relative to the normal 17 of the radial plane 21. Likewise a radially outwardly directed surface 23 is inclined by the inner inclination angle relative to the normal 17 of the radial plane 22. Thus the radially inwardly directed engagement contact surface 21 of a circular ring segment 7, 9 is essentially parallel to the radially outwardly directed surface 23 of an adjacent circular ring segment 7, 9.

[0030] In the example depicted a radial extension 25 of the groove 15 is 4.47 mm, but in other embodiments it can assume other values. A radial extension of the end surface of the circular ring segment 7, 9 is indicated by reference number 27 and can essentially correspond to or be equal to the radial extension 25 of the groove 15. A depth of the groove is indicated by reference number 29 and can be, for example, 1.0 to 1.5 times the radial extension 25 of the groove 15. In the illustrated embodiment the groove 15 has a base or floor 31, which is semicircular in the cross-section illustrated in FIG. 1C. Such a groove can be easily produced by milling.

[0031] In FIG. 1C a sharp edge 32 can also be seen, which is formed between the radially inwardly directed engagement contact surface 21 and the end surface 19 of a circular ring segment 7 or 9 or between the radially outwardly directed engagement surface 23 and the end surface 19 of a circular ring segment 7 or 9.

[0032] FIG. 1D illustrates the clamping element 1 illustrated in FIG. 1A in a plan view, from which a thickness 33 of, e.g., approximately 23 to 25 mm results. On the end side 19 the circular ring segments 7, 9 are disposed and on the back side 35 a guide groove 37 is incorporated in a central region in order to be able to move the clamping element 1 in the radial direction 5 for clamping a workpiece.

[0033] FIG. 1E is a further side view of the clamping element 1 and furthermore allows a guide rail 37 to be seen on the back side 35. FIG. 1F illustrates a rear view of the clamping element 1 illustrated in FIG. 1A in end view, wherein the attachment openings 11 and the guide rails 37 can be seen, which extend along the radial direction 5.

[0034] FIG. 2 illustrates in a schematic perspective depiction the clamping element 1, wherein the end side 19 with the circular ring segments 7, 9 is substantially recognizable. The circular ring segments 7, 9 each forms a segment of 120 and are partially interrupted due to the existing attachment through-holes 11. The circular ring segments 7, 9 are identically spaced from one another in the radial direction 5. In other embodiments the circular ring segments can be irregularly distributed, wherein, for example, certain radial regions of the clamping element remain unprofiled.

[0035] FIG. 3 illustrates a clamping-element set or clamping-jaw set 40 with three clamping elements 1, as are illustrated in FIGS. 1A to 1F and 2. In a device for holding a workpiece these three clamping elements 1 are movable toward each other and movable away from each other along the radial directions 5 in order to hold a workpiece or release the workpiece.

[0036] The three clamping elements 1 illustrated in FIG. 3 can, for example, be produced together in the arrangement and orientation as shown in order to produce the circular ring segments 7, 9 and the grooves 15. For this purpose the three clamping elements 1 would only need to be fixed with the help of the attachment through-holes in this arrangement and orientation as drawn and shown and, for example, milled in this position.

[0037] FIG. 4 shows in a schematic perspective depiction a part of a device 100 for holding a workpiece 43 according to an embodiment of the present disclosure. The depiction in FIG. 4 is a perspective sectional depiction obliquely between an axial direction 3 and a radial direction 5. The workpiece 43 is a semi-finished product, in particular a thick-walled cylindrical plastic tube, and an adapter 45 is attached to an end side of the tube, which adapter includes projections 47. The projections 47 are in engagement with circular ring segments 9 of the clamping element 1. A workpiece of smaller extension, including a suitably profiled end surface or attached to a smaller adapter, can be brought into engagement with the circular ring segments 7, after which, for example, the processing of the workpiece 43 illustrated in FIG. 4 is ended.

[0038] A device 49 can be provided, for example, for radial moving of the clamping element 1 in radial direction 5. Reference number 51 indicates a manual chuck. The clamping element 1 (also referred to as aluminum jaws) can, for example, be produced from aluminum and processed by milling and turning so as to produce the circular ring segments 7 and 9 as well as the grooves 15.

[0039] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved devices for holding a workpiece.

[0040] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0041] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0042]

TABLE-US-00001 Ref. No. Description 1 Clamping element (clamping jaws) 3 Axial direction 5 Radial direction 7 Circular ring segment or engagement structure with small radius 9 Circular ring structure or engagement structure with large radius 11 Through-holes 13 Detail view 15 Groove 19 End surface 21 Radially inwardly directed engagement contact surface 22 Radial plane 23 Radially outwardly directed surface 25 Radial extension of the groove 27 Radial extension of the circular ring segment 29 Depth of the grooves 31 Groove base 32 Sharp edge 35 Back side of the guide groove 37 Guide-rail or -groove 40 Clamping-element set or clamping-jaw set 43 Semi-finished product 45 Adapter 47 Projection 49, 51 Manual jaw chuck r1, r2 r3, . . . rn Radial positions Inner inclination angle