GB1566927A - Cutting tool - Google Patents

Description

(54) CUTTING TOOL (71) We, SANDVIK AKTIEBOLAG, of Fack, S-811 01, Sandviken 1, Sweden, a Joint Stock Company, organised in accordance with the laws of Sweden, do hereby declare the invention, for which we Pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the follow mg statement: The present invention relates to a cutting tool comprising a tool body and an insertprovided support body, said support body being mechanically secured into a recess in the tool body.

Various milling cutters exist in which the cutting inserts are exchangeable and indexable. A common type of insert used in milling cutters is centrally apertured for the reception of a locking screw thereinto.

When indexing the insert to provide a new cutting edge it is necessary to loosen the screw to such extent that the edge supporting surface or surfaces of the insert are free from engagement. The procedure of having all inserts of a milling cutter loosened and tightened for every change of insert is time consuming and, hence, causes loss of production, in particular when a change of cutting edge must be effected without being able to loosen the milling cutter from its machine spindle. Further, with large diameter milling cutters the accessibility is limited to such extent that it is often very difficult to get an Allen key engaged with the locking screws of the centrally apertured inserts.

For the above reasons it is a requirement to provide a cutting tool having an insert and its support body easily detachable and exchangeable as one unit. Such a solution is also needed from another aspect. With certain inserts, particularly round inserts it is always very time consuming to adjust the insert to be accurately indexed so as to provide a new cutting edge, an adjustment which causes problems to the operator since the inserts have usually an appreciable temperature after cutting work. A technical solution providing for detachment of insert and support body as one unit should eliminate such problem.

A cutting tool according to the present invention comprises a tool body, a recess in the tool body providing support surfaces, a support body for a cutting insert fitting into the recess, abutment surfaces on the support body complementary to the support surfaces on the tool body and holding means for holding the support body on the tool body, the holding means comprising a locking member having a screw-threaded shank connecting the support body and the tool body, and a slot located in, and opening out into, one face of the tool body or the support body, the slot being capable of accepting part of the said shank if it is passed through the opening in the said face in a direction transverse to its axis so that by screwing the locking member in one direction the support body can be loosened and removed from the tool body (the shank then passing through the said opening of the slot), or replaced on the tool body, and by screwing the locking member in the other direction whilst abutment surfaces of the support body are against support surfaces of the tool body, the two bodies are locked firmly in operative position.

The invention will now be described more specifically below, with reference to the accompanying drawings showing some embodiments of the invention, in which Figure 1 is a sectional view of a milling cutter embodiment of the invention, taken on line I-I in Figure 2; Figure 2 is a view from the underneath side of the milling cutter shown in Figure 1; Figure 3 is a perspective view of an insert-provided support body engageable with a cutting tool body as shown in Figures 1 and 2; Figure 4 is a front view of a cutting tool body according to one embodiment of the invention; Figure 5 is a sectional view similar to Figure 1 of an alternative milling cutter embodiment of the invention; Figure 6 is a view from the underneath side of the milling cutter shown in Figure 5;; Figure 7 is a perspective view of a support body to be secured to a cutting tool body in the invention; and Figure 8 is a perspective view of another support body to be secured to a cutting tool body in the present invention.

Referring to Figures 1 to 3 a milling cutter tool body 10 is provided with equally spaced recesses around its circumference for the receipt of support bodies 12 upon which cutting inserts 11 are located, only one of which is shown in the drawings. Each insert 11 is centrally apertured to receive a locking screw 13 which can be screwed into said support body 12. Other kinds of locking means for the insert may alternatively be applied. The embodiment shown in the drawings comprises inserts of round shape but it is to be understood that the invention is also useful with other conventional types of inserts.

The support body 12 shown comprises two sides meeting at right angles, only one of which is visible in Figure 3 where it is indicated at 14. The said two sides have abutment surfaces which rest against two complementary support surfaces, indicated 15 and 16 in Figure 2. The support body 12 is adapted to rest additionally against an axial support surface 17 in the milling cutter tool body 10.

The support body 12 is clamped into the tool body 10 by means of a locking member consisting of a screw 18 exteriorly provided with two threads, one left-hand and one right-hand, said screw 18 being threaded on the one hand into a transverse hole 19 through the support body and on the other hand into an abutment member 20. The arrangement is such that the shank of the screw 18 passes through an axial slot 21 provided in the tool body lying between the recess which receives the support body 12, and a cylindrical bore 22 that extends parallel with support surfaces 15, 16 to receive the abutment member 20 so that this is axially slidable in the bore 22.

The cylindrical bore 22 and the slot 21 terminate at the outside of the cutter body, thus enabling the support body 12 with the screw 18 and the locking member 20 to be easily detached as one unit by axial displacement of the member 20 out of the end of the bore and of the shank of the screw out of the opening of the slot 21, upon loosening the screw 18. The abutment member 20 is preferably in the shape of a cylindrical swivelling nut but could alternatively be of another configuration, The abutment member 20, when clamped by the screw 18, is received in cylindrical bore 22 and also partially received in a recess 23 in the support body 12.

As is best shown in Figure 3, the side surface 14 of support body 12 is provided with two spaced projecting pads 24 and 25 with plane outer surfaces forming the abutment surfaces which are adapted to rest against support surface 16 of the recess receiving said support body in the milling cutter body. An additional pad 26 is provided to rest against the axial support surface 17 of said recess. This arrangement creates good and adequate support of body 12. It is to be understood, however, that other configurations of support body 12 are possible.

With the embodiment of milling cutter shown in Figures 1 and 2 both the recess adapted to receive support body 12 as well as cylindrical bore 22 extend in the axial direction of the cutter body. The invention is also useful if said recess and cylindrical bore extend at an angle relative to the central axis of the milling cutter body.

With the embodiment shown in Figure 4 the invention is applied to an oblong tool holder where the recess adapted to receive support body 12 and the adjacent cylindrical bore 22 extend substantially in the direction of the tool holder shaft 10.

In Figures 5 to 8 there are shown some alternative embodiments of the invention in which the slot 21 is provided directly in the support body 12. The slot 21 extends more or less diagonally and emerges at that end surface bearing the pad 26 which is adapted to function as axial abutment surface against the tool body 10. The support body 12 is suitably of parallelepipedic shape. In the embodiment of Figures 5 to 7 one edge of the parallelepiped is cut away to form a face 28 at right angles to, and slightly longer than, the slot 21, and the screw 18, which is threaded into a hole in the tool body, has an enlarged head which bears against the face 28.

With the embodiment shown in Figure 8 the slot 21 is provided with an intermediate cylindrically widened portion 27 adapted to receive cylindrical swivelling nut 20 with which the clamping screw 18 is threadably engageable. As with the embodiment of Figures 1 to 3 or that in Figure 4, the two threads are in opposite senses, though it would be conceivable to have them of the same sense but with different pitches.

With the embodiment of Figures 5 to 8 the screw 18 can remain in the tool body when the support body is removed therefrom, the part of its shank which lies in the slot passing through the opening of the slot 21 as the support body comes free of the tool body and entering into it as the support body is first offered to the tool body with its screw.

WHAT WE CLAIM IS: 1. A cutting tool comprising a tool body, a recess in the tool body providing support surfaces, a support body for a cutting insert fitting into the recess, abutment surfaces on the support body complementary to the support surfaces on the tool body and holding means for holding the support body on the tool body, the holding means comprising a locking member having a screw-threaded shank connecting the support body and the tool body, and a slot located in, and opening out into, one face of the tool body or the support body, the slot being capable of accepting part of the shank if it is passed through the opening in a direction transverse to its axis, so that by screwing the locking member in one direction the support body can be loosened and removed from the tool body (the shank then passing through the said opening of the slot), or replaced on the tool body, and by screwing the locking member in the other direction whilst abutment surfaces of the support body are against support surfaces of the tool body, the two bodies are locked firmly in operative position.

2. A cutting tool according to claim 1, wherein the slot is located in the tool body between the recess and a cylindrical bore lying adjacent and parallel with a side of the recess, the locking member being threadably engaged with an abutment member displaceable in said bore such that the support body and the locking member are jointly detachable from the tool body.

3. A cutting tool according to claim 2 wherein the abutment member is a cylindrical nut.

4. A cutting tool according to claim 2 or claim 3 wherein the locking member is also threaded into a hole passing through the support body, the threads having different pitches or being in different senses.

5. A cutting tool according to claim 1 wherein the locking member screws into a threaded hole in the tool body, the slot being located in the support body.

6. A cutting tool according to claim 1 or claim 5 wherein the support body is of generally parallelepipedic shape with the slot generally diagonally therethrough.

7. A cutting tool according to claim 6 wherein the locking member has an enlarged head to abut a face on the support body through which the slot emerges at right angles to the said face.

8. A cutting tool according to any one of claims 5 to 7 wherein the locking member is threadably engaged with a cylindrical nut received in the support body in a cylindrically widened intermediate portion of the slot, the threads having different pitches or being in different senses.

9. A cutting tool according to any one of the preceding claims, wherein the tool body is that of a rotary milling cutter having equally spaced recesses around its circumference for the receipt of insert-provided support bodies, the recesses extending in the axial direction of the milling cutter.

10. A cutting tool according to any one of claims 1 to 8, wherein the tool body is in the shape of an oblong cutting tool holder having a recess at one end portion thereof for the receipt of an insert-provided support body, said recess extendmg in the axial direction of the shaft of the tool holder.

11. A cutting tool substantially as shown in Figures 1 to 3, or Figure 4, or Figures 5 to 7 or Figure 8 of the accompanying drawings and described herein with reference thereto.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. slot passing through the opening of the slot 21 as the support body comes free of the tool body and entering into it as the support body is first offered to the tool body with its screw. WHAT WE CLAIM IS:

1. A cutting tool comprising a tool body, a recess in the tool body providing support surfaces, a support body for a cutting insert fitting into the recess, abutment surfaces on the support body complementary to the support surfaces on the tool body and holding means for holding the support body on the tool body, the holding means comprising a locking member having a screw-threaded shank connecting the support body and the tool body, and a slot located in, and opening out into, one face of the tool body or the support body, the slot being capable of accepting part of the shank if it is passed through the opening in a direction transverse to its axis, so that by screwing the locking member in one direction the support body can be loosened and removed from the tool body (the shank then passing through the said opening of the slot), or replaced on the tool body, and by screwing the locking member in the other direction whilst abutment surfaces of the support body are against support surfaces of the tool body, the two bodies are locked firmly in operative position.

2. A cutting tool according to claim 1, wherein the slot is located in the tool body between the recess and a cylindrical bore lying adjacent and parallel with a side of the recess, the locking member being threadably engaged with an abutment member displaceable in said bore such that the support body and the locking member are jointly detachable from the tool body.

3. A cutting tool according to claim 2 wherein the abutment member is a cylindrical nut.

4. A cutting tool according to claim 2 or claim 3 wherein the locking member is also threaded into a hole passing through the support body, the threads having different pitches or being in different senses.

5. A cutting tool according to claim 1 wherein the locking member screws into a threaded hole in the tool body, the slot being located in the support body.

6. A cutting tool according to claim 1 or claim 5 wherein the support body is of generally parallelepipedic shape with the slot generally diagonally therethrough.

7. A cutting tool according to claim 6 wherein the locking member has an enlarged head to abut a face on the support body through which the slot emerges at right angles to the said face.

8. A cutting tool according to any one of claims 5 to 7 wherein the locking member is threadably engaged with a cylindrical nut received in the support body in a cylindrically widened intermediate portion of the slot, the threads having different pitches or being in different senses.

9. A cutting tool according to any one of the preceding claims, wherein the tool body is that of a rotary milling cutter having equally spaced recesses around its circumference for the receipt of insert-provided support bodies, the recesses extending in the axial direction of the milling cutter.

10. A cutting tool according to any one of claims 1 to 8, wherein the tool body is in the shape of an oblong cutting tool holder having a recess at one end portion thereof for the receipt of an insert-provided support body, said recess extendmg in the axial direction of the shaft of the tool holder.

11. A cutting tool substantially as shown in Figures 1 to 3, or Figure 4, or Figures 5 to 7 or Figure 8 of the accompanying drawings and described herein with reference thereto.