ROUND KNIFE, CUTTING ASSEMBLY AND METHOD FOR CUTTING TIRE COMPONENTS
20210245383 · 2021-08-12
Inventors
Cpc classification
B26D7/2614
PERFORMING OPERATIONS; TRANSPORTING
B26D1/205
PERFORMING OPERATIONS; TRANSPORTING
B26D3/003
PERFORMING OPERATIONS; TRANSPORTING
B26D1/245
PERFORMING OPERATIONS; TRANSPORTING
B29D30/46
PERFORMING OPERATIONS; TRANSPORTING
B26D2001/0046
PERFORMING OPERATIONS; TRANSPORTING
International classification
B26D3/00
PERFORMING OPERATIONS; TRANSPORTING
B26D1/00
PERFORMING OPERATIONS; TRANSPORTING
B26D1/24
PERFORMING OPERATIONS; TRANSPORTING
B26D7/26
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Disclosed are a round knife, a cutting assembly, and a method for cutting tire components wherein the round knife includes a carrier that is rotatable about a rotation axis (X) and a plurality of first edge segments which are arranged to be mounted side-by-side in a circumferential direction (G) about the rotation axis (X) to the carrier to form a circular cutting edge (E) extending concentrically about the rotation axis (X), wherein the segment body is arranged to be spaced apart from the carrier in the radial direction (R) at the center between the first lateral side and the second lateral side.
Claims
1. A round knife for cutting tire components, wherein the round knife comprises a carrier that is rotatable about a rotation axis and a plurality of first edge segments which are arranged to be mounted side-by-side in a circumferential direction about the rotation axis to said carrier to form a circular cutting edge extending concentrically about the rotation axis, wherein each first edge segment comprises a segment body that, when mounted to the carrier, comprises an outer side facing away from the rotation axis and an inner side facing towards the rotation axis, wherein the segment body further comprises a first lateral side and a second lateral side extending between the outer side and the inner side on opposite sides of the segment body in the circumferential direction, wherein the outer side is convex to form a part of the circular cutting edge, wherein the inner side is arranged to abut the carrier in a radial direction perpendicular to the rotation axis at or near the first lateral side and the second lateral side, while the segment body is arranged to be spaced apart from the carrier in the same radial direction at the center between the first lateral side and the second lateral side.
2. The round knife according to claim 1, wherein the plurality of first edge segments are within a tolerance of less than thirty micrometers from each other in the circumferential direction at the circular cutting edge.
3. The round knife according to claim 2, wherein the plurality of first edge segments are arranged to be spaced apart from each other in the circumferential direction at the circular cutting edge within said tolerance.
4. The round knife according to claim 1, wherein the plurality of first edge segments are arranged to abut each other in the circumferential direction at the circular cutting edge.
5. The round knife according to claim 4, wherein the circular cutting edge is continuous.
6. The round knife according to claim 4, wherein the abutment between the plurality of first edge segments in the circumferential direction is tensionless.
7. The round knife according to claim 1, wherein the plurality of first edge segments are spaced apart from each other in the circumferential direction at the inner side over at least one hundred micrometers.
8. The round knife according to claim 1, wherein the segment body further comprises a first lateral side and a second lateral side extending between the outer side and the inner side on opposite sides of the segment body in the circumferential direction, wherein the first lateral side of one of the first edge segments faces the second lateral side of a directly adjacent first edge segment and diverges away from said second lateral side from the outer side towards the inner side.
9. The round knife according to claim 8, wherein the first lateral side and the second lateral side comprise a first lateral contact surface and a second lateral contact surface, respectively, extending parallel to a radial direction perpendicular to the rotation axis over at least two millimeters from the circular cutting edge towards the rotation axis.
10. The round knife according to claim 1, wherein the inner side is at least partially concave.
11. The round knife according to claim 1, wherein the inner side is arranged to contact the carrier at a first support position and a second support position at or near the first lateral side and the second lateral side, respectively, wherein the inner side comprises a first inner contact surface and a second inner contact surface at the location of the first support position and the second support position, respectively, wherein the inner contact surfaces are planar and extend in a direction perpendicular to the radial direction at the respective support positions.
12. The round knife according to claim 1, wherein the outer side extends along a circular arc with a first radius, wherein the inner side is arranged to contact the carrier at a first support position and a second support position at or near the first lateral side and the second lateral side, respectively, wherein the first support position and the second support position lie on a circular arc with a third radius concentric to the circular arc of the outer side, wherein at least a part of the inner side between the first support position and the second support position extends along a circular arc with a fourth radius that is smaller than the third radius.
13. The round knife according to claim 1, wherein the carrier is provided with a first circumferential support surface extending in the circumferential direction at a third radius with respect to the rotation axis for supporting the plurality of first edge segments in the radial direction perpendicular to said rotation axis, wherein the inner side has a fourth radius that is smaller than the third radius.
14. The round knife according to claim 1, wherein the carrier comprises a circular carrier body.
15. The round knife according to claim 14, wherein the circular carrier body is a disc or a ring.
16. The round knife according to claim 1, wherein the carrier comprises a first mounting surface for mounting the plurality of first edge segments to the carrier in an axial direction parallel to the rotation axis.
17. The round knife according to claim 16, wherein the first mounting surface extends in a radial plane perpendicular to the rotation axis.
18. The round knife according to claim 16, wherein the carrier further comprises a first circumferential support surface extending in the circumferential direction for supporting the plurality of first edge segments in a radial direction perpendicular to said rotation axis, wherein the carrier is provided with an undercut that connects the first mounting surface with the first circumferential support surface and that is arranged to lie back from the plurality of first edge segments.
19. The round knife according to claim 16, wherein the carrier comprises a mid-plane perpendicular to the rotation axis, wherein the first mounting surface is located at one side of the mid-plane, wherein the carrier further comprises a second mounting surface on the opposite side of the mid-plane with respect to the first mounting surface, wherein the round knife further comprises a plurality of second edge segments which are arranged to be mounted side-by-side in the circumferential direction to the second mounting surface, wherein the round knife is invertible to alternately form the circular cutting edge with the plurality of first edge segments or the plurality of second edge segments.
20. The round knife according to claim 19, wherein each second edge segment forms a third circumferential edge and a fourth circumferential edge opposite to the third circumferential edge in the axial direction, wherein each second edge segment is invertible to alternately align the third circumferential edge or the fourth circumferential edge with the circular cutting edge.
21. An edge segment for use in a round knife, wherein the edge segment comprises a segment body that comprises an outer side and an inner side, wherein the segment body further comprises a first lateral side and a second lateral side extending between the outer side and the inner side on opposite sides of the segment body in the circumferential direction, wherein the outer side is convex to form a part of the circular cutting edge and extends along a circular arc with a first radius, wherein the inner side is arranged to contact the carrier at a first support position and a second support position at or near the first lateral side and the second lateral side, respectively, wherein the first support position and the second support position lie on a circular arc with a third radius concentric to the circular arc of the outer side, wherein the at least a part of the inner side between the first support position and the second support position extends along a circular arc with a fourth radius that is smaller than the third radius.
22. A method for cutting tire components with the use of a round knife, wherein the method comprises the step of: cutting a tire component using the round knife according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The invention will be elucidated on the basis of an exemplary embodiment shown in the attached schematic drawings, in which:
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DETAILED DESCRIPTION OF THE INVENTION
[0058]
[0059] The round knife 1 according to the present invention differs from the round knife of the prior art in that it is a segmented knife. As shown in
[0060] The round knife 1 according to the present invention preferably has a diameter of at least four hundred millimeters and more preferably at least five hundred millimeters. This relatively large diameter may reduce the forward pressure force exerted on the tire components 9 during cutting, to prevent deformations. The segmented round knife 1 has the advantage that the carrier 2 can be made of a material that can be machined accurately at low costs, while, the edge segments 4 can be made from a harder, more costly material.
[0061] As best seen in
[0062] In this exemplary embodiment, the first mounting surface 23 extends in a radial plane P perpendicular to the rotation axis X. Hence, all of the edge segments 4 can be mounted to the carrier 2 in a common plane, being the radial plane P.
[0063] The carrier 2 comprises a circumferential support surface 24 extending in the circumferential direction G for supporting the plurality of edge segments 4 in a radial direction R perpendicular to the rotation axis X. Preferably, the circumferential support surface 24 is cylindrical or substantially cylindrical about the rotation axis X. The carrier 2 further comprises a main surface 25 that is arranged lie flush with the edge segments 4. In other words, the distance between the mounting surface 23 and the main surface 25 of the carrier 2 in the axial direction H is preferably equal or substantially equal to the thickness of the edge segments 4 in the same axial direction H.
[0064] As shown in
[0065] In this exemplary embodiment, as shown in
[0066] Preferably, the circular cutting edge E formed by the edge segments 4 is as round as possible, if not a substantially perfect circle. Positioning of the edge segments 4 relative to each other is therefore an important aspect of the invention. Any misalignment between the edge segments 4 may cause a stepped or serrated, saw-tooth like cutting edge which is undesirable. The details of the edge segments 4 described below are directed at obtaining a circular cutting edge E that is as round as possible.
[0067]
[0068] The edge segment 4 is arranged to be within a tolerance T of less than thirty micrometers from the adjacent edge segments 4 in the circumferential direction G at or near the circular cutting edge E, as schematically shown in
[0069] The tolerance range is chosen such that the circular cutting edge E can be substantially continuous, at least to the human eye. Moreover, with tolerances T this small, the risk of the cords 91 getting stuck between the edge segments 4 is virtually non-existent. Hence, the segmented round knife 2 according to the present invention can effectively cut in the same way and with the same quality as a conventional round knife with an integral circular cutting edge, as shown in
[0070] As shown in
[0071] As best seen in
[0072] As further shown in
[0073] As shown in
[0074] The combination of the two point support of the edge segments 4 on the circumferential support surface 24 and the clamping of the rear surface 57 on the mounting surface 23 results in a very stable, three point support for the edge segments 4.
[0075] In this exemplary embodiment, as shown in
[0076] As shown in
[0077] The edge segments 4 are preferably made of or comprise hard metal, e.g. with a hardness of two thousand HV (Vickers Pyramid Number). Optionally, the first edge segments 4 may be coated with a hardness improving coating, like Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD), to considerably increase the hardness of the edge segments 4, e.g. to three or four thousand HV.
[0078]
[0079] The alternative round knife 101 is reversible or invertible to alternately form the circular cutting edge E with the plurality of first edge segments 141 or the plurality of second edge segments 142. In particular, the alternative round knife 101 can be inverted such that in one position, the first edge segments 141 cooperate with the rectilinear counter-knife 3 of
[0080] More in particular, it can be seen in
[0081]
[0082] In particular, as best seen in
[0083] The inner contact surfaces 281, 282 are planar or substantially planar. Preferably, the planar inner contact surfaces 281, 282 extend in a direction normal or perpendicular to the radial direction R at the respective contact positions C, D. Hence, the contact force exerted by the alternative edge segment 241 on the carrier 2 at or near the contact positions C, D can be directed in said radial direction R. This may prevent damage to the corners of the alternative inner side 252 with the respective alternative lateral sides 253, 254.
[0084] The remaining part of the alternative inner side 252, i.e. the part not being formed by the inner contact surfaces 281, 282, can be of the same concave shape as described earlier in relation to the previous embodiments. In particular, the remaining part of the alternative inner side 252 may extend along a circular arc with a fourth radius R4 that is smaller than the third radius R3.
[0085] As best seen in
[0086] By providing the lateral contact surfaces 283, 284, it can be prevented that the mutually facing alternative lateral sides 253, 254 of directly adjacent alternative edge segments 241 already start to diverge, and thus leave a gap between the respective alternative edge segments 241, within the area in which the further alternative round knife 201 and the rectilinear counter-knife 3 of
[0087] A method for cutting tire components 9 with the use of the round knife 1, 101, 201 according to any of the previously discussed embodiments will be briefly discussed hereafter with reference to
[0088] The method comprises the steps of mounting the plurality of (first) edge segments 4, 141, 241 to the carrier 2, 102, cutting the tire components 9 and replacing one or more of the (first) edge segments 4, 141, 241 while leaving at least one or more of the other (first) edge segments 4, 141, 241 in place. Hence, the round knife 1, 101 does not have to be replaced as a whole when only a limited number of (first) edge segments 4, 141, 241 are worn and/or damaged. The (first) edge segments 4, 141, 241 may be mounted to the carrier (2, 102) with the use of the aforementioned fasteners 7, e.g. bolts, optionally in combination with glue. The glue may be heated to release the fasteners 7 and to facilitate removal of the (first) edge segments 4, 141, 241.
[0089] When the (first) edge segments 4, 141, 241 are provided with the first circumferential edge 61, 161 and the second circumferential edge 62, 162, the method may further comprise the step of inverting one or more (first) edge segments 4, 141, 241 to alternate align the first circumferential edge 61, 161 or the second circumferential edge 62, 162 with the circular cutting edge E.
[0090] When using the alternative round knife 102, the method may further comprise the step of inverting the round knife 101 as a whole to alternately form the circular cutting edge E with the plurality of first edge segments 141 or the plurality of second edge segments 142.
[0091] Finally, when each second edge segment 142 is provided with the third circumferential edge 163 and the fourth circumferential edge 164, the method may further comprise the step of inverting one or more of the second edge segments 142 to alternately align the third circumferential edge 163 or the fourth circumferential edge 164 with the circular cutting edge E.
[0092]
[0093] As shown in
[0094] The round counter-knife 30 may comprise a continues circular cutting knife with a substantially continues circular cutting edge E′. Alternatively, the round counter-knife 30 may also comprise a carrier that is rotatable about a rotation axis X′, which carrier is provided with a plurality of edge segments 34 (indicated by dotted lines in
[0095] Schematically indicated in
[0096] The round counter-knife 30 with the plurality of edge segments 34 allows to provide substantially the same advantages to the counter-knife 30 as provided to the round knife 1 according to the present invention.
[0097]
[0098] As shown in
[0099] However in this fourth exemplary embodiment, the counter-knife 3 also comprises a carrier that is provided with a plurality of edge segments 35 which are arranged to be mounted side-by-side along a cutting edge E″ of the counter knife 3′. The edge segments 35 comprise a substantially rectilinear upper cutting face. The edge segments 35 are arranged side by side to form a rectilinear cutting edge E″, which cutting edge E″ extends in the traversing direction Y.
[0100] The counter-knife 3′ with the plurality of edge segments 35 allows to provide substantially the same advantages to the counter-knife 3′ as provided to the round knife 1 according to the present invention.
[0101] It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.
LIST OF REFERENCE NUMERALS
[0102] 1 round knife [0103] 2 carrier [0104] 20 carrier body [0105] 21 circumference [0106] 22 undercut [0107] 23 mounting surface [0108] 24 circumferential support surface [0109] 25 main surface [0110] 26 undercutting surface [0111] 27 mounting hole [0112] 28 mounting hole [0113] 3 rectilinear counter-knife [0114] 3′ rectilinear counter-knife [0115] 30 round counter-knife [0116] 34 edge segment [0117] 4 edge segment [0118] 50 segment body [0119] 51 outer side [0120] 52 inner side [0121] 53 first lateral side [0122] 54 second lateral side [0123] 55 fastener hole [0124] 56 fastener hole [0125] 57 rear surface [0126] 58 front surface [0127] 61 first circumferential edge [0128] 62 second circumferential edge [0129] 7 fastener [0130] 9 tire component [0131] 90 cord fabric [0132] 91 cords [0133] 101 alternative round knife [0134] 123 first mounting surface [0135] 129 second mounting surface [0136] 141 first edge segment [0137] 142 second edge segment [0138] 161 first circumferential edge [0139] 162 second circumferential edge [0140] 163 third circumferential edge [0141] 164 fourth circumferential edge [0142] 171 fastener [0143] 172 fastener [0144] 201 further alternative round knife [0145] 241 alternative edge segment [0146] 252 alternative inner side [0147] 253 alternative first lateral side [0148] 254 alternative second lateral side [0149] 281 first inner contact surface [0150] 282 second inner contact surface [0151] 283 first lateral contact surface [0152] 284 second lateral contact surface [0153] A edge position [0154] B edge position [0155] C support position [0156] D support position [0157] E circular cutting edge [0158] E′ circular cutting edge [0159] G circumferential direction [0160] H axial direction [0161] M mid-plane [0162] P radial plane [0163] R radial direction [0164] R1 first radius [0165] R2 second radius [0166] R3 third radius [0167] R4 fourth radius [0168] S circle sector [0169] T tolerance [0170] X rotation axis [0171] X′ rotation axis [0172] Y traversing direction [0173] Y′ traversing direction [0174] Z overlap distance