CN215960158U - Planing tool with chip breaker - Google Patents

Abstract

The utility model discloses a planing tool with a chip breaker, comprising: an outer cutter head, wherein an outer cutting window is arranged on the outer cutter head and comprises an outer front edge; an inner cutter head disposed within and rotatable relative to the outer cutter head, the inner cutter head having an inner cutting window at a front end thereof, the inner cutting window including an inner front edge; the top surface of the outer front edge is intersected with the inner wall surface of the outer tool bit to form an outer pre-cutting edge, and the top surface of the outer front edge is provided with at least one first chip breaker groove so as to divide the outer pre-cutting edge into at least two sections; the top surface of the inner front edge is intersected with the outer wall surface of the inner tool bit to form an inner pre-cutting edge, at least one second chip breaker groove is formed in the top surface of the inner front edge to divide the inner pre-cutting edge into at least two sections, and the first chip breaker groove and the second chip breaker groove are staggered. The planing tool with the structure can cut the tissues on the front side of the tool into multiple sections, so that the tissue volume is reduced, and the tissues can be conveniently sucked into the internal cutting window.

Description

Planing tool with chip breaker

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a planing tool with a chip breaker.

Background

The planing tool is applied to arthroscopic surgery and ear-nose-throat surgery to realize cutting treatment on soft tissues. The existing planing tool generally comprises an outer cutter tube and an inner cutter tube arranged in the outer cutter tube, wherein the far end of the outer cutter tube is provided with an outer planing window, the side edge of the outer planing window is provided with a plurality of outer cutter teeth, each outer cutter tooth comprises an outer tooth point, an outer tooth side surface and an outer tooth bottom surface, and the outer tooth side surface and the inner wall surface of the outer cutter tube are intersected to form an outer planing edge. The distal end of interior sword pipe is provided with interior cutting window, and the side edge of interior cutting window is provided with a plurality of interior sword teeth, and interior sword tooth includes interior prong, internal tooth side and internal tooth bottom surface, and the internal tooth side intersects with the outer wall surface of interior sword pipe and forms interior cutting edge. When the inner cutter tube rotates relative to the outer cutter tube, the outer cutter teeth and the inner cutter teeth move relatively to cut off soft tissues extending into the outer cutting window, the tissues are sucked into the inner cutting window, and the scraps are sucked out through a vacuum system, so that the cutting purpose is achieved.

The front edge top surface of an external cutting window and the front edge top surface of an internal cutting window of the existing planing tool are both 0-degree rear angles (namely, the included angle between the front edge top surface of the external cutting window and a reference line vertical to the central line of the cross section of the external cutter head corresponding to the external cutting window is 0 degree, and the included angle between the front edge top surface of the internal cutting window and the reference line vertical to the central line of the cross section of the internal cutter head corresponding to the internal cutting window is 0 degree), and the blade surface is blunt-edged cutting and is not sharp, so that the cutting effect on the tissues on the front side of the tool is poor.

Disclosure of Invention

In view of the above-described prior art, the present invention is directed to providing a planing tool with a chip breaker having a high cutting efficiency for tissue on the front side of the tool.

In order to solve the above technical problem, the present invention provides a planing tool having a chip breaker, including: the outer cutter head is provided with an outer cutting window, and the outer cutting window comprises two outer edges in the circumferential direction and an outer front edge connected between the far ends of the two outer edges; the inner cutter head is arranged in the outer cutter head and can rotate relative to the outer cutter head in the circumferential direction, the front end of the inner cutter head is provided with an inner cutting window, and the inner cutting window comprises two inner side edges in the circumferential direction and an inner front edge connected between the far ends of the two inner side edges; the top surface of the outer front edge is intersected with the inner wall surface of the outer tool bit to form an outer pre-cutting edge, and the top surface of the outer front edge is provided with at least one first chip breaker groove so as to divide the outer pre-cutting edge into at least two sections; the top surface of the inner front edge and the outer wall surface of the inner cutter head are intersected to form an inner pre-cutting blade, at least one second chip breaker groove is formed in the top surface of the inner front edge to divide the inner pre-cutting blade into at least two sections, and the first chip breaker groove and the second chip breaker groove are staggered mutually.

According to the planing tool with the chip breakers, as the first chip breaker and the second chip breaker are respectively arranged on the top surface of the outer front edge and the top surface of the inner front edge, and the outer pre-cutting edge and the inner pre-cutting edge are respectively divided into at least two sections by the first chip breaker and the second chip breaker, the tissue on the front side of the planing tool can be cut into multiple sections, so that the tissue volume is reduced, and the planing tool can be conveniently sucked into the inner cutting window.

In one embodiment, the top surface of the outer leading edge is inclined to the outside with an outer rake angle α 3, the outer rake angle α 3 being the angle between the intersection w3g3 of a normal section s5-s5 through any point w3 on the outer pre-cutting edge with the top surface of the outer leading edge and a reference line w3x5 located within the normal section s5-s5 and perpendicular to the tangent through point w 3; the top surface of the inner front edge is inclined inwardly with an inner inclination angle β 3, the inner inclination angle β 3 being an angle between an intersection line n3h3 of a normal section s6-s6 passing through any point n3 on the inner pre-cutting edge with the top surface of the inner front edge and a reference line n3x6 located within the normal section s6-s6 and perpendicular to a tangent line passing through the point n 3.

In one embodiment, the first chip breaker is a through groove that penetrates in a width direction of the top surface of the outer leading edge, and the second chip breaker is a through groove that penetrates in a width direction of the top surface of the inner leading edge.

In one embodiment, the first chip breaker has a V-shape with a wide top and a narrow bottom in cross section, and the second chip breaker has a V-shape with a wide top and a narrow bottom.

In one embodiment, the first chip breaker is located on one or both sides of the axis of the outer tool bit, and the second chip breaker is located on one or both sides of the axis of the inner tool bit.

In one embodiment, the bottom surfaces of the first chip breakers are inclined outwardly with respect to a reference line perpendicular to the center line of the outer head cross-section to which they correspond, and the bottom surfaces of the second chip breakers are inclined inwardly with respect to a reference line perpendicular to the center line of the inner head cross-section to which they correspond.

In one embodiment, the top surface of the outer front edge is convex and the top surface of the inner front edge is concave and convex.

In one embodiment, the top surface of the outer front edge is an inverted "V" shape and the top surface of the inner front edge is a "V" shape.

In one embodiment, at least one of the two outer side edges includes a plurality of outer cutter teeth including a first tooth tip, two first tooth flank surfaces and a first tooth bottom surface, the first tooth flank surfaces intersecting an inner wall surface of the outer cutter head to form a first outer cutting edge; at least one of the two inner side edges comprises a plurality of inner cutter teeth, each inner cutter tooth comprises a second tooth tip, two second tooth side surfaces and a second tooth side surface, and the second tooth side surfaces are intersected with the outer wall surface of the inner cutter head to form a first inner cutting edge.

In one embodiment, the distance between the first tooth tip on the same outer edge and the axis of the outer cutter head gradually decreases from the proximal end to the distal end of the outer cutter head, and the distance between the second tooth tip on the same inner edge and the axis of the inner cutter head gradually decreases from the proximal end to the distal end of the inner cutter head.

The advantageous effects of the additional features of the present invention will be explained in the detailed description section of the present specification.

Drawings

Fig. 1 is a perspective view of a planing tool having chip breakers in an embodiment of the present invention;

FIG. 2 is a perspective view of an outer blade tube assembly of the planing tool having chip breakers shown in FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at I;

FIGS. 4 and 5 are perspective views of an outer cutter of the outer cutter assembly shown in FIG. 2, with FIG. 4 being a perspective view from the front to the rear and FIG. 5 being a perspective view from the rear to the front;

FIG. 6 is a front view of the outer blade assembly shown in FIG. 2;

FIG. 7 is a top view of an outer cutter head of the outer cutter assembly shown in FIG. 2;

FIG. 8 is a left side view of the outer blade assembly shown in FIG. 2;

FIG. 9 is a perspective view of an inner blade tube assembly of the planing tool having chip breakers shown in FIG. 1;

FIG. 10 is an enlarged partial schematic view at P of FIG. 9;

FIGS. 11 and 12 are perspective views of the inner cutter assembly shown in FIG. 9, with FIG. 11 being a perspective view from the front to the rear and FIG. 12 being a perspective view from the rear to the front;

FIG. 13 is a front view of the inner blade assembly shown in FIG. 10;

FIG. 14 is a top view of an inner cutter head of the inner cutter assembly shown in FIG. 10;

FIG. 15 is a left side view of the inner blade assembly shown in FIG. 10;

FIG. 16 is a schematic view of the engagement of the outer cutter head with the inner cutter head, shown with the inner cutter head rotated 100 degrees counterclockwise relative to the outer cutter head;

FIG. 17 is a cross-sectional view taken along line L-L of FIG. 16;

FIG. 18 is a cross-sectional view taken along line M-M of FIG. 16;

FIG. 19 is a cross-sectional view taken along line N-N of FIG. 16;

FIG. 20 is a schematic view of the engagement of the outer cutter head with the inner cutter head, shown with the inner cutter head rotated 180 degrees counterclockwise relative to the outer cutter head;

fig. 21 is a cross-sectional view taken along line O-O in fig. 20.

Description of reference numerals: 10. planing a cutter; 20. an outer cutter tube assembly; 30. a base body; 40. an outer cutter bar; 41. a first connector; 50. an outer cutter head; 51. externally cutting a window; 52. an outer edge; 53. an outer cutter tooth; 531. a first tooth tip; 532. a first flank face; 533. a first tooth bottom surface; 534. externally cutting the side edge; 535. externally cutting a bottom blade; 536. the back of the tooth; 54. an inner wall surface; 55. an outer front edge; 551. a top surface of the outer front edge; 552. an outside pre-cutting edge; 553. a first chip breaker groove; 56. a first mounting hole; 57. a first welding groove; 60. an inner cutter tube assembly; 70. a connecting member; 80. an inner cutter bar; 81. a second mounting hole; 82. a second welding groove; 90. an inner cutter head; 91. internally cutting a window; 92. an inner edge; 93. inner cutter teeth; 931. a second tooth tip; 932. a second flank; 933. a second tooth bottom surface; 934. an inner cutting side edge; 935. internally cutting a bottom edge; 94. an outer wall surface; 95. an inner front edge; 951. a top surface of the inner front edge; 952. an inner pre-cutting edge; 953. a second chip breaker; 96. a second connector.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the features in the following embodiments and examples may be combined with each other without conflict.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

As shown in fig. 1, the planing tool 10 having chip breakers in one embodiment of the present invention includes an outer blade pipe assembly 20 and an inner blade pipe assembly 60, the inner blade pipe assembly 60 being disposed within the outer blade pipe assembly 20 and being circumferentially rotatable with respect to the outer blade pipe assembly 20.

Fig. 2 is a perspective view of the outer cutter tube assembly 20, and as shown in the figure, the outer cutter tube assembly 20 includes a holder body 30 and an outer cutter tube, the holder body 30 is a cylindrical structure, and a fixing hole is disposed at a front end of the holder body 30. The outer knife tube has a proximal end near the holder 30 and a distal end near the holder 30, the proximal end of the outer knife tube is inserted into the fixing hole of the holder 30, and the outer knife tube includes a tubular outer knife bar 40 and an outer knife head 50 connected to the distal end of the outer knife bar 40.

As shown in fig. 2 and 3, the outer cutter bar 40 and the outer cutter head 50 are a split structure, the distal end of the outer cutter bar 40 is provided with a stepped first connecting head 41, the proximal end of the outer cutter head 50 is provided with a stepped first mounting hole 56 which is matched with the first connecting head 41, the first connecting head 41 is inserted into the first mounting hole 56, and the two are fixed by welding. In order to enhance the welding stability of the outer cutter head 50 and the outer cutter bar 40, at least one first welding groove 57 extending along the axial direction is formed on the proximal end of the outer cutter head 50, and the end face of the proximal end of the outer cutter head 50 and the first welding groove 57 are welded with the first connecting head 41, so that the outer cutter head 50 and the outer cutter bar 40 are welded in the circumferential direction and the axial direction at the same time, and the connecting strength is increased. The exemplary first welding grooves 57 are three, and the three first welding grooves 57 are evenly distributed in the circumferential direction. Alternatively, the first connector 41 and the first mounting hole 56 are reversed, i.e. the first connector 41 is arranged at the proximal end of the outer cutter head 50 and the first mounting hole 56 is arranged at the distal end of the outer cutter bar 40.

As shown in fig. 4 and 5, an outer cutting window 51 is formed in the tube wall of the outer cutter head 50 near the distal end, the outer cutting window 51 includes two outer side edges 52 located on the circumferential direction of the outer cutter head 50 and an outer front edge 55 connected between the distal ends of the outer side edges 52, at least one outer side edge 52 of the two outer side edges 52 is a saw-toothed structure, the outer side edge 52 includes a plurality of outer cutter teeth 53 arranged along the axial direction of the outer cutter head 50, the outer cutter teeth 53 include a first tooth tip 531, two first tooth side surfaces 532 located on the two sides of the first tooth tip 531 on the axial direction of the outer cutter head 50 and a first tooth bottom surface 533 transitionally connected between the bottom ends of the first tooth side surfaces 532 of the two adjacent outer cutter teeth 53, the first tooth side surfaces 532 intersect with the inner wall surface 54 of the outer cutter head 50 to form an outer cutting side edge 534, and the first tooth bottom surface 533 intersects with the inner wall surface 54 of the outer cutter head 50 to form an outer cutting bottom edge 535. In this embodiment, the two outer edges 52 are saw-toothed, so that the inner cutting head 90 can cut in both directions.

As shown in fig. 6, the first tooth bottom surface 533 is inclined outward at a first camber angle α 1, and the first camber angle α 1 is an angle between an intersection w1g1 of a first normal section s1-s1 passing through any point w1 on the outside cutting bottom edge 535 and the first tooth bottom surface, and a first reference line w1x1 located within the first normal section s1-s1 and perpendicular to a tangent line passing through the point w 1. Since the outer cutting bottom edge 535 comprises the first camber angle α 1, thereby forming a sharp cutting edge having a sharp edge characteristic and cutting ability in a direction perpendicular to any one segment of the edge profile in addition to having cutting performance in a radial direction, the entire curved edge profile has no cutting dead space.

As shown in FIG. 6, the first flank face is inclined outwardly at a second camber angle α 2, the second camber angle α 2 being the angle between the intersection w2g2 of the third normal section s3-s3 passing through any point w2 on the outside cutting side edge 534 with the first flank face and a third reference line w2x3 located within the third normal section s3-s3 and perpendicular to the tangent passing through point w 2. Since the outer cutting side edge 534 includes the second camber angle α 2, a sharp cutting edge is formed, which has a sharp edge characteristic and cutting ability in a vertical direction of any one blade profile in addition to cutting performance in a radial direction, and there is no cutting dead angle in the entire curved edge profile. The second camber angle α 2 is the same as or different from the first camber angle α 1.

As shown in fig. 4, the outer cutter tooth 53 is a triangular tooth as an example, both side surfaces of the outer cutter tooth 53 in the axial direction of the outer cutter head 50 are first tooth flank surfaces 532, the tips of the first tooth flank surfaces 532 intersect to form a first tooth tip 531, and the first tooth tip 531 is inclined outward. The exemplary outer cutter tooth 53 further includes a tooth back surface 536 facing away from the inner wall surface 54 of the outer cutter head 50, and a top end of the tooth back surface 536 is inclined outward with respect to a bottom end, so that a relief angle is formed at the back of the outer cutter tooth 53 to increase sharpness thereof, and a tissue located outside the outer cutter tooth 53 is more easily cut by a negative pressure suction edge portion in the cutter, thereby improving a planing efficiency.

As shown in fig. 6, as an example, the distance between the first tooth tip 531 on the same outer side edge 52 and the center line a 1 of the outer cutter head 50 gradually decreases in the direction from the proximal end to the distal end of the outer cutter head 50, that is, the line L1 connecting the first tooth tip 531 on the same outer side edge 52 is inclined forward at an inclination angle γ 1 with respect to the center line a 1 of the outer cutter tube, which can effectively ensure that the strength of the outer cutter head 50 can withstand a larger torque during cutting without breaking near the trailing end, and also can form a shearing motion effect that gradually cuts into the tissue in the axial direction, thereby cutting the tissue more easily and efficiently.

Referring to fig. 4 and 5, the top surface 551 of the outer front edge, as an example, meets the inner wall surface 54 of the outer cutter head 50 to form an outer pre-cutting edge 552, and the outer pre-cutting edge 552 cooperates with the inner pre-cutting edge 952 on the inner cutter head 90 to cut tissue at the front side of the cutter.

As shown in fig. 7, the top surface 551 of the outer front edge slopes outwardly at a third camber angle α 3, the third camber angle α 3 being the angle between the intersection w3g3 of the fifth normal section s5-s5 passing through any point w3 on the outer pre-cutting edge 552 and the top surface 551 of the outer front edge, and a fifth reference line w3x5 located within the fifth normal section s5-s5 and perpendicular to the tangent passing through the point w 3. Since the outside pre-cutting edge 552 includes the third camber angle α 3, a sharp cutting edge is formed, which has cutting performance in the radial direction, and has sharp cutting edge characteristics and cutting ability in the vertical direction of any section of blade profile, and the entire curved edge profile has no cutting dead angle. The third camber angle α 3 is the same as or different from the first camber angle α 1.

With further reference to fig. 4, 5 and 8, the exemplary outer front edge top surface 551 is convex and convex, and in this embodiment, the outer front edge top surface 551 is inverted "V" shape, so that the outer pre-cutting edge 552 forms a height difference at the end of the outer cutter head 50, forming a shearing effect at the end, and facilitating the cutting of the end pre-cut segment. Preferably, the top surface 551 of the outer front edge is provided with at least one first chip breaker 553, the first chip breaker 553 serving to divide the outer pre-cutting edge 552 into at least two segments, so that the tissue at the front side of the cutter can be cut into multiple segments, reducing the tissue volume, to facilitate suction into the inner cutting window 91. As an example, the first chip breakers 553 are four, and the four first chip breakers 553 are symmetrically disposed at both sides of the axis of the outer cutter 50. As an example, the first chip breaker 553 is a through groove that penetrates in the width direction of the top surface 551 of the outer front edge, and the cross section of the first chip breaker 553 is "V" shaped wide at the top and narrow at the bottom. The outer end of the bottom surface of the first chip breaker 553 as an example is inclined to the outside with respect to the inner end.

As shown in fig. 9, the exemplary inner knife tube assembly 60 includes an inner knife tube and a connector 70, wherein one end of the inner knife tube close to the holder body 30 is a proximal end, the other end is a distal end, the proximal end of the inner knife tube is connected to the connector 70, the connector 70 is used for connecting to a knife driving device (not shown), and the knife driving device drives the inner knife tube to rotate through the connector 70. The inner blade tube includes a hollow inner blade bar 80 and an inner blade head 90 connected to the distal end of the inner blade bar 80.

As shown in fig. 9 and 10, the inner cutter bar 80 and the inner cutter head 90 are in a split structure, a stepped second mounting hole 81 is provided at the distal end of the inner cutter bar 80, a second connector 96 engaged with the second mounting hole 81 is provided at the proximal end of the inner cutter head 90, the second connector 96 is inserted into the second mounting hole 81, and the two are fixed by welding. In order to enhance the welding stability of the inner cutter head 90 and the inner cutter rod 80, at least one second welding groove 82 extending along the axial direction is formed in the far end of the inner cutter rod 80, and the end face of the far end of the inner cutter rod 80 and the second welding groove 82 are welded with the second connector 96, so that the inner cutter rod 80 and the inner cutter head 90 are welded in the circumferential direction and the axial direction simultaneously, and the connecting strength is increased. The exemplary second welding grooves 82 are three, and the three second welding grooves 82 are evenly distributed in the circumferential direction. In order to increase the overall strength of the cutter, the end faces of the distal end of the inner blade 80 and the proximal end of the outer blade 50 are axially displaced from each other, and the positions of the second welding groove 82 and the first welding groove 57 are circumferentially displaced from each other. Alternatively, the second connector 96 and the second mounting hole 81 are reversed, i.e., the second connector 96 is disposed at the distal end of the inner cutter bar 80 and the second mounting hole 81 is disposed at the proximal end of the inner cutter head 90.

As shown in fig. 11 and 12, an inner cutting window 91 is formed in a pipe wall of the inner cutter head 90 near the distal end, the inner cutting window 91 includes two inner side edges 92 located on the circumferential direction of the inner cutter head 90 and an inner front edge 95 connected between the distal ends of the inner side edges 92, at least one inner side edge 92 of the two inner side edges 92 is of a sawtooth structure, the inner side edge 92 includes a plurality of inner cutter teeth 93 arranged along the axial direction of the inner cutter head 90, each inner cutter tooth 93 includes a second tooth tip 931, two second tooth side surfaces 932 located on two axial sides of the inner cutter head 90 and a second tooth bottom surface 933 transitionally connected between bottom ends of the second tooth side surfaces 932 of two adjacent inner cutter teeth 93, the second tooth side surfaces intersect with an outer wall surface 94 of the inner cutter head 90 to form inner cutting side edges 934, and the second tooth bottom surface 933 intersects with the outer wall surface 94 of the inner cutter head 90 to form an inner cutting bottom edge 935. In this embodiment, the inner edges 92 are serrated, so that the inner cutting head 90 can cut in both forward and reverse directions.

As shown in fig. 13, the second tooth bottom surface 933 is inclined inward at a first inclination angle β 1, where the first inclination angle β 1 is an angle between an intersection line n1h1 of a second normal section s2-s2 passing through any point n1 on the inner cutting bottom edge 935 and the second tooth bottom surface and a second reference line n1x2 located within the second normal section s2-s2 and perpendicular to a tangent line passing through the point n 1. Since the second tooth bottom surface 933 is inclined inward at the first inclination angle β 1, a sharp cutting edge is formed, which has cutting performance in the radial direction and has sharp edge characteristics and cutting ability in the vertical direction of any blade profile, and the entire curved edge profile has no cutting dead angle.

As shown in fig. 13, the second flank surface 932 is inclined inwardly at a second inclination angle β 2, where the second inclination angle β 2 is an angle between an intersection line n2h2 of a fourth normal section s4-s4 passing through any point n2 on the inner cutting side edge 934 and the second flank surface 932 and a fourth reference line n2x4 located within the fourth normal section s4-s4 and perpendicular to a tangent line passing through the point n 2. The second flank surface inclines inwards at a second inclination angle beta 2, so that a sharp cutting edge is formed, the cutting edge has cutting performance in the radial direction, and has sharp cutting edge characteristics and cutting capacity in the vertical direction of any section of blade-shaped profile, and the whole curve cutting edge profile has no cutting dead angle. Beta 2 is the same as or different from beta 1.

As shown in fig. 11 and 12, the inner cutter tooth 93 in the present embodiment is a triangular tooth, two side surfaces of the inner cutter tooth 93 in the axial direction of the inner cutter head 90 are second side surfaces 932, the top ends of the second side surfaces 932 intersect to form a second tip 931, and the second tip 931 inclines outward.

As shown in fig. 13, as an example, the distance between the second tooth tip 931 on the same inside edge 92 and the center line a2 of the inner cutter head 90 gradually decreases from the proximal end to the distal end of the inner cutter head 90, that is, the connecting line L2 of the second tooth tip 931 on the same inside edge 92 is inclined forward relative to the center line a2 of the inner cutter tube at an inclination angle γ 2, which can effectively ensure that the strength of the inner cutter head 90 can bear larger torque during cutting without breaking near the trailing end, and also form a shearing motion effect that gradually cuts into tissue along the axial direction, so that the tissue can be cut more easily and the cutting efficiency is higher.

Referring to fig. 11 and 12, the top surface 951 of the exemplary inner leading edge intersects the outer wall surface 94 of the inner blade 90 to form an inner pre-cutting edge 952, which cooperates with the outer pre-cutting edge 552 on the outer blade 50 to sever tissue located on the leading side of the blade.

As shown in fig. 14, the top surface 951 of the inner front edge is inclined inwardly at a third inclination angle β 3, the third inclination angle β 3 being an angle between an intersection line n3h3 of a sixth normal section s6-s6 passing through any point n3 on the inner pre-cutting edge 952 and the top surface of the inner front edge and a sixth reference line n3x6 located within the sixth normal section s6-s6 and perpendicular to a tangent line passing through the point n 3. The top surface of the inner front edge inclines inwards at a third inner inclination angle beta 3, so that a sharp cutting edge is formed, the cutting edge has cutting performance in the radial direction, the sharp cutting edge has sharp cutting edge characteristics and cutting capability in the vertical direction of any section of blade-shaped profile, and the whole curve cutting edge profile has no cutting dead angle. Beta.3 is the same as or different from beta.1.

With further reference to fig. 11, 12 and 15, the exemplary inner front edge top surface 951 is concave and inwardly concave, and in this embodiment the inner front edge top surface 951 is "V" shaped, so that the inner pre-cutting edge 952 creates a step at the end of the inner cutter head 90, creating a shearing effect at the end, facilitating end pre-cut segment cutting. Preferably, the top surface 951 of the inner front edge is provided with at least one second chip breaker 953, the second chip breaker 953 being adapted to divide the inner pre-cutting edge 952 into at least two segments, so that tissue at the front side of the tool can be cut into multiple segments, reducing the tissue volume for easy suction into the inner cutting window 91. As an example, the second chip breakers 953 are two, and the two second chip breakers 953 are symmetrically arranged on both sides of the axis of the inner cutter 90. As an example, the second chip breaker 953 is a through groove penetrating in the width direction of the top face 951 of the inner front edge, and the cross section of the second chip breaker 953 is V-shaped with a wide top and a narrow bottom. The inner end of the bottom surface of the second chip breaker 953 is inclined inward with respect to the outer end.

In operation, the knife drive drives the inner knife tube assembly 60 to rotate clockwise or counterclockwise relative to the outer knife tube assembly 20. Fig. 16-19 illustrate the schematic cutting view of the inner blade assembly 60 rotated 100 degrees counterclockwise relative to the outer blade assembly 20, and as shown, the outer blade teeth 53 are axially offset from the inner blade teeth 93, i.e., the first tooth tip 531 of the outer blade teeth 53 is opposite to the second tooth bottom surface 933 of the inner blade teeth 93, and the first tooth bottom surface 533 of the outer blade teeth 53 is opposite to the second tooth tip 931 of the inner blade teeth 93. Because the first tooth tip 531, the first tooth flank 532 and the first tooth bottom surface 533 are outwards inclined and the second tooth tip 931, the second tooth flank 932 and the second tooth bottom surface 933 are inwards inclined, the inner cutter head 90 forms a sharp cutting edge when the outer cutter teeth 53 and the inner cutter teeth 93 are staggered in the reciprocating planing process, namely a scissor-like cutting structure is formed at the matching positions of the inner cutter teeth 93 and the outer cutter teeth 53, so that the tissue can be cut efficiently. Moreover, since the first tooth bottom surface 533 is inclined outward to form the sharp outer cutting bottom edge 535 with the first outer inclination angle α 1, and the second tooth bottom surface 933 is inclined inward to form the sharp inner cutting bottom edge 935 with the first inner inclination angle β 1, when cutting high elastic tissue such as fascia, the first tooth tip of the inner cutter tooth 93 starts to cut and grab tissue, the grabbed tissue is pressed between the two cutter teeth while continuing to rotate, and when rotating to the tooth bottom, the outer cutting bottom edge 535 and the inner cutting bottom edge 935 complete final cutting and separate tissue, so that the tissue is easier to be cut by the negative pressure suction edge part in the cutter, thereby improving the planing efficiency.

As shown in fig. 16, since all the first tips 531 are inclined forward at the inclination angle γ 1 with respect to the center line a 1 of the outer blade tube and the connecting line L2 of all the second tips 931 is inclined forward at the inclination angle γ 2 with respect to the center line a2 of the inner blade tube, shear is formed in the axial direction in addition to the shear formed in the rotational direction of the inner blade 90, that is, a double shear effect like scissors is formed, so that the cut tissue is made more labor-saving and the cutting efficiency is made higher.

As shown in fig. 20 and 21, since the top surface 551 of the outer front edge intersects with the inner wall surface 54 of the outer tool bit 50 to form the outer pre-cutting edge 552 with the third outer inclination angle α 3, and the top surface 951 of the inner front edge intersects with the outer wall surface 94 of the inner tool bit 90 to form the inner pre-cutting edge 952 with the third inner inclination angle β 3, the sharpness of the outer pre-cutting edge 552 and the inner pre-cutting edge 952 is increased, and the cutting efficiency is improved. The tissue at the front side of the cutter is cut and sucked into the inner cutting window 91 by the outer pre-cutting edge 552 and the inner pre-cutting edge 952. Moreover, since the top surface 551 of the outer front edge is provided with the first chip breaker 553 and the top surface 951 of the inner front edge is provided with the at least one second chip breaker 953, the tissue can be cut into multiple sections, the volume of the tissue is reduced, the load of the inner cutter head is reduced, and the cutting efficiency is improved.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims (10)

1. A planing tool having chip breakers, comprising:

the outer cutter head is provided with an outer cutting window, and the outer cutting window comprises two outer edges in the circumferential direction and an outer front edge connected between the far ends of the two outer edges;

the inner cutter head is arranged in the outer cutter head and can rotate relative to the outer cutter head in the circumferential direction, the front end of the inner cutter head is provided with an inner cutting window, and the inner cutting window comprises two inner side edges in the circumferential direction and an inner front edge connected between the far ends of the two inner side edges;

the cutting tool is characterized in that the top surface of the outer front edge is intersected with the inner wall surface of the outer tool bit to form an outer pre-cutting edge, and the top surface of the outer front edge is provided with at least one first chip breaker groove to divide the outer pre-cutting edge into at least two sections; the top surface of the inner front edge and the outer wall surface of the inner cutter head are intersected to form an inner pre-cutting blade, at least one second chip breaker groove is formed in the top surface of the inner front edge to divide the inner pre-cutting blade into at least two sections, and the first chip breaker groove and the second chip breaker groove are staggered mutually.

2. The planing tool with chip breakers according to claim 1, wherein the top surface of said outer front edge is inclined towards the outside with an outer inclination angle α 3, said outer inclination angle α 3 being the angle between the intersection w3g3 of a normal section s5-s5 through any point w3 on said outer pre-cutting edge with the top surface of said outer front edge and a reference line w3x5 located within said normal section s5-s5 and perpendicular to a tangent line through a point w 3; the top surface of the inner front edge is inclined inwardly with an inner inclination angle β 3, the inner inclination angle β 3 being an angle between an intersection line n3h3 of a normal section s6-s6 passing through any point n3 on the inner pre-cutting edge with the top surface of the inner front edge and a reference line n3x6 located within the normal section s6-s6 and perpendicular to a tangent line passing through the point n 3.

3. The planing tool having chip breakers according to claim 1 wherein said first chip breakers are through slots running through in the width direction of the top surface of said outer front edge and said second chip breakers are through slots running through in the width direction of the top surface of said inner front edge.

4. The planing tool with chip breakers of claim 1 wherein said first chip breakers have a "V" shape with a wide top and a narrow bottom in cross section and said second chip breakers have a "V" shape with a wide top and a narrow bottom.

5. The planing tool having chip breakers according to claim 1 wherein said first chip breakers are located on one or both sides of the axis of said outer cutter head and said second chip breakers are located on one or both sides of the axis of said inner cutter head.

6. The planing tool with chip breakers of claim 1 wherein the bottom surfaces of said first chip breakers are inclined outwardly and the bottom surfaces of said second chip breakers are inclined inwardly.

7. The planing tool with chip breakers according to claim 1 wherein the top surface of said outer front edge is convex outwardly convex and the top surface of said inner front edge is concave inwardly concave.

8. The planing tool with chip breakers according to claim 7 wherein the top surface of said outer front edge is inverted "V" shaped and the top surface of said inner front edge is "V" shaped.

9. The planing tool having a chip breaker as defined in any one of claims 1 to 8 wherein at least one of said two outer side edges includes a plurality of outer cutter teeth, said outer cutter teeth including a first tip, two first flanks and a first bottom flank, said first flanks intersecting an inner wall surface of said outer cutter head to form a first outer cutting edge; at least one of the two inner side edges comprises a plurality of inner cutter teeth, each inner cutter tooth comprises a second tooth tip, two second tooth side surfaces and a second tooth side surface, and the second tooth side surfaces are intersected with the outer wall surface of the inner cutter head to form a first inner cutting edge.

10. The planing tool having chip breakers of claim 9 wherein said first tooth point on the same said outer edge is progressively less distant from the axis of said outer bit in the direction from the proximal end to the distal end of said outer bit and said second tooth point on the same said inner edge is progressively less distant from the axis of said inner bit in the direction from the proximal end to the distal end of said inner bit.

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