A CUTTING TOOL AND A TOOL ASSEMBLY APPARATUS

Abstract: A cutting tool for use in lathes and screw machines which comprises a plurality of discrete cutter sections (9, 11, 12, 13, 14) fixed in side-by-side relationship so that they can all simultaneously act upon a single workpiece. The use of separate cutter sections rather than an integral cutter allows for ready replacement of damaged or worn cutter sections without scrapping the whole cutter and allows cutters having a complex form to be assembled from a small number of standardized cutter sections. An automatic tool assembly apparatus is provided for assembling such cutting tools from their component parts.

Description: A CUTTING TOOL AND A TOOL ASSEMBLY APPARATUS This invention relates to a cutting tool and to a tool assembly apparatus. The production of cutting tools having complex contours for use in conjunction with machine tools such as lathes, screw machines and numerically-controlled and other types of automatic machine tools is attended with considerable difficulties. Hitherto,- when it has been necessary to provide a cutting tool having a complex cutting edge, a slab of cutting tool material (such as high-speed cutting steel, tungsten carbide, compacted polycrystalline diamond or compacted cubic boron nitride) has been ground to produce the necessary complex cutting edge. The grinding of the complex cutting edges requires costly skilled labor to form the tool originally and to resharpen it at intervals during use. Furthermore, should even a small part of the complex cutting edge become chipped in use, the whole tool has to be sent back for lengthy regrinding, or entirely replaced. Unless spare cutting tools are kept at hand, chipping or breakage of the cutting tool may lead to lengthy down¬ time of expensive machine tools, but the provision of the necessary spare cutting tools is also expensive and wasteful since, when only a limited number of parts are to be cut by any particular cutting tool, the spare tools may never be used. There is thus a need for a cutting tool which can be produced and replaced rapidly using relatively unskilled labor and which does not need to be replaced entirely if a small part of a complex cutting edge becomes broken or chipped. This invention seeks to provide such a cutting tool and an apparatus for assembling such a cutting tooL Accordingly, this invention provides a cutting tool comprising a cutter having a cutting " edge, a holder for the cutter and means for retaining the cutter in the holder, characterized in that: the cutter comprises a plurality of separate cutter sections, each cutter section having a cutting edge; the holder has a support surface against which the cutter sections can lie; and the retaining means comprises a cutter sections retainer capable of retaining the cutter sections on the support surface in side-by-side relationship so that the cutting edges of all the cutter sections can all be applied to a single work piece, the retainer being capable of preventing relative movement between the various cutter sections and between the cutter sections and the holder. The invention also provides a tool assembly apparatus capable of assembling a cutting tool of the invention and comprising a plurality of cutter section storage sections each capable of storing at least one cutter section; a holder storage station capable of storing at least one holder; a retainer storage station capable of storing at least one retainer; and a component transfer member capable of transporting the cutter sections, the holder and the retainer from their respective storage stations and assembling them to form the cutting tooL This invention is based upon the realization that the vast majority of the complicated cutting edges provided on cutting tools in industrial practice are combinations of a relatively limited number of simple geometric shapes. According¬ ly, by providing a selection of discrete cutter sections, each having a cutting edge of simple geometric shape, a very large number of complex shapes can be rapidly and easily assembled by relatively unskilled labor by placing the cutter sections required on the support surface in side-by-sϊde relationship, adjusting their relative longitud- inal positions to provide the desired cutting edge and then locking the cutter sections in position relative to each other and to the holder by means of the retainer. To be commereiaEy useful, the cutter sections should of course be made available in a variety of widths. Providing each different shape of cutter section in widths of from about L5 mm. to 25 mm. in increments of 0.37 mm. will be sufficient for most industrial purposes. Although the cutting edge of each cutter section can of course assume an infinite variety of shapes (and obviously special shapes can be produced to order when necessary) the standard shapes which will need to be provided for most purposes are limited in number; for example, providing square, pointed, angled, rectangular, arc-shaped, knurled, circular, wavy and offset cutting edges will suffice for most purposes. OMPI In a preferred form of the cutting tool of the invention, each cutter section is provided with a pair of flat parallel contact faces on its opposed sides so that when the cutting tool is assembled with the cutter sections disposed side-by-side the contact faces of adjacent cutter sections will lie in contact with one another, and the retainer comprises a first clamp capable of exerting pressure on the cutter sections in a direction substantially perpendicular to the contact faces thereof, thereby holding the cutter sections in side-by-side relationship, and a second clamp capable of exerting pressure on the cutter sections in a direction substantially in the planes of the contact faces and substantially perpendicular to the support surface on the holder. Conveniently, the second clamp comprises a second clamp body member having a cutter section contact surface and a holder contact surface spaced from the cutter section contact surface such that when the cutter section contact surface contacts the cutter sections, the holder contact surface will contact the holder, the second clamp body member also being provided with a securing device whereby it may be releasably secured to the holder. In certain applications, it may be desirable to adjust the rake angle of the cutting edges on the cutter sections. In order to avoid having to provide a variety of cutter sections having variable rake angles, the holder may be made in two parts, namely a body section and a movable section pivotally mounted on the body section and capable of being releasably secured to the body section in any one of a plurality of differing positions. The movable section carries the support surface so that the rake angles of the cutting edges of the cutter sections can be varied by pivoting the movable member relative to the body member. Alternatively, the holder may comprise a body section having a recess therein and a removable member at least part of which can be accommodated in the recess. The support surface is carried by the removable member and the retainer, when retaining the cutter sections on the support surface, also retains the removable member fixed in position relative to the body section. By providing a variety of substantially wedge-shaped removable members, the angle of the support surface relative to the body section of the holder can be varied merely by replacing one removable member with another. In the cutting tool of the invention, it is of course essential that the cutter sections retainer be capable of retaining the cutter sections on the support surface so firmly that they do not move relative to one another or to the support surface while the cutting edges of the cutter sections are operating on the work piece. The forces exerted on the cutter sections can be very large, and there are two presently preferred methods which have been discovered which will hold even small cutter seetions against the forces exerted thereon during cutting. In the first of these two methods, the holder is provided with at least one stop surface capable of abutting a cutter section at a point remote from the cutting edge thereof, such that abutment of the stop surface against the cutter section helps to prevent movement of the cutter section away from a work piece when the cutting edge of the cutter section engages the work piece. One obvious problem in providing such a stop surface is that it will often be desired to move the various cutter sections toward and away from a work piece relative to one another so that the contour of the complex cutting edge formed by the cutting edges of the various cutter sections can be altered. Since the provision of a movable stop surfaee of conventional type is difficult in the cutting tool of the invention, preferably the cutter sections, the holder and the cutter sections retainer are shaped so that, when the cutting tool is assembled, a cavity is left adjacent the end of the cutter sections remote from their cutting edges, the cutting tool also comprising a filler material which can be inserted into this cavity in flowable (liquid, semi-solid or plastic) form and will thereafter harden to form a stop which engages the ends of the cutter sections remote from the cutting edges thereof. Further details of the preferred, types of filling material and cavity-filling techniques are described below with reference to the first cutting tool of the invention shown in Figs. 1-10. The second preferred method for preventing relative movement between the cutter sections and between the cutter sections and the support surface during cutting operations is to provide each of the cutter sections with at least one raised portion on its surface which, in the assembled tool, lies adjacent either the support surface or the second clamp, the cutting tool also comprising a shim capable of being placed between the raised portion and the adjacent portion of the support surface or the second clamp, the shim being provided with, or being capable of being deformed to form, at least one recess accommodating the raised portion of the cutter sections. In most eases, it is convenient to use a deformable shim which is simply pressed onto the raised portions of the cutter sections so that the shim will deform around the raised portions and form the appropriate recess. However, in some cases, particularly when using a double-ended cutter section (as described in more detail below with reference to Fig. 34), it may be convenient to use a shim having a preformed recess. Preferred embodiments of the cutting tool and tool assembly apparatus of the invention will now be described, though by way of illustration only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an assembled first cutting tool of the invention from in front, above and to one side; Fig. 2 is a top plan view of the support block of the cutting tool shown in Fig. is Fig. 3 is a side elevation of the support block shown in Fig. 2j Fig. 4 is a top plan view of the body section of the holder shown in Fig. 1; Fig. 5 is a front elevation of the body section shown in Fig. 4 (Fig. 5 is turned 90° counterclockwise relative to the position of the body section shown in Fig. 1); Fig. 6 is a top plan view of the second clamp body member shown in Fig. 1; Fig. 7 is a side elevation of the second clamp body member shown in Fig. 6; Fig. 8 is a top plan view of one of the cutter sections shown in Fig. 1; Fig. 9 is a side elevation of the cutter section shown in Fig. 8; Fig. 10 is a front elevation of the cutter section shown in Figs. 8 and 9; Fig. 11 is a top plan view of a second cutter section which can be substituted for that shown in Figs. 8-10; Fig. 12 is a side elevation of the second cutter section shown in Fig. 11; Fig. 13 is a top plan view of the front portion of a second cutting tool of the invention with the second clamp body member removed for ease of illustration; Fig. 14 is a side elevation of the front part of the second cutting tool shown in Fig. 13, again with the second clamp body member removed for ease of illustration; Fig. 15 is a top plan view of a third cutting tool of the invention having a cylindrical holder; Fig. 16 is a side elevation of the third cutting tool shown in Fig. 15 Fig. 17 is a top plan view of a third cutter section of the invention; Fig. 18 is a side elevation of the third cutter section shown in Fig. 17; Fig. 19 is a side elevation of an alternative second clamp body member and associated shim which may be substituted for the second clamp member shown in Fig. U Fig. 20 is a top plan view of a fourth cutting tool of the invention having a cylindrical holder; Fig. 21 is a partial front elevation of a fifth cutting tool of the invention using a different type of second clamp; Fig. 22 is a partial front elevation of a sixth cutting tool of the invention illustrating another type of second clamp; Fig. 23 is an underneath plan view of an alternative form of second clamp body means which may be substituted for that shown in Fig. 6; Fig 24 is a top plan view of an apparatus for assembling cutting tools of the invention; Fig. 25 is a side elevation of the apparatus shown in Fig. 24 looking in the direction of the arrows in that Fig.; Fig. 26 is a top plan view of a fourth cutter insert of the invention; Fig. 27 is a side elevation of the fourth cutter insert shown in Fig. 26; Fig. 28 is a side elevation of a seventh cutting tool of the invention; Fig. 29 is a top plan view of a tool assembly apparatus of the invention; Fig. 30 is a side elevation of the tool assembly apparatus shown in Fig. 29 looking in the direction of the arrows in that Fig.; Fig. 31 is a top plan view of an eighth cutting tool of the invention in which the holder is provided with a movable section; Fig. 32 is a side elevation of the eighth cutting tool shown in Fig. 31; Fig. 33 is a side elevation similar to Fig. 32 but showing the cutting tool with the movable section of the holder in a different position; Fig. 34 is a side elevation of a fifth cutter insert provided with two separate cutting edges; Fig. 35 is a side elevation of the fifth cutter insert shown in Fig. 34 together with adjacent parts of the holder and the shim used therewith; Fig. 36 is a side elevation of a sixth cutter insert; Fig. 37 is a side elevation of a seventh cutter insert together with adjacent parts of the holder and a shim used therewith; Fig. 38 is a side elevation of an eighth cutter insert and a shim used therewith; Fig. 39 is a side elevation of the front portion of a ninth cutting tool of the invention; Fig. 40 is a side elevation' of the front portion of a tenth cutting tool of the invention in which the holder is provided with a removable section; Fig. 41 is a top plan view of the holder and cutter inserts only of an eleventh cutting tool of the invention; Fig. 42 is a top plan view, similar to Fig. 41, of the holder and cutter inserts of a twelveth cutting tool of the invention; Fig. 43 is a top plan view, similar to Figs. 41 and 42, of a thirteenth cutting tool of the invention. The first cutting tool of the invention shown in Figs. 1-10 is held in position by a conventional support member 1 which can be of any convenient form and may be attached to any conventional lathe, turret lathe, threading machine or other OM automatic or numerically-controlled machine' tool. The cutting tool itself, which is supported by the support member 1, comprises five cutter sections 9, 11, 12, 13 and 14 which vary in shape but which are each provided at the upward edge of their forward end with a cutting edge, the cutter sections 9, 11, 12, 13, and 14 being 05 disposed so that their various cutting edges lie adjacent one another to form, in effect, a single cutting edge of complex form which can be applied to a single workpiece. It will readily be seen that, by forming the cutting edges of the cutter sections 9, 11, 12, 13 and 14 in various simple geometric shapes, a wide variety of complex contures can be cut by the cutting tooL 10 The cutting tool further comprises a holder formed in two sections, namely a body section 5 and a removable section or support block 7 which, as best seen in Fig. 3, has the form of a trapezoidal prism. As best seen in Figs. 4 and 5, the front part of the body section 5 has cut therein a recess 22, which is substantially cuboidal but which is provided with relieved rear vertical edges 21 for ease of manufacture. The 15 support block 7 completely fills the lower part of the recess 22 and a triangular prismatic portion of the support block 7 projects forwardly beyond the front face of the body section 5, thus giving the holder a sloping front face 17 which provides cutter clearance. If desired, the front face 17 may be hand ground to provide proper clearance to any specific tool contour. As best seen in Fig. 9, the cutters 9, 11, 12, 20 13 and 14 are also provided with sloping front faces to provide proper clearance for their cutting edges. As best seen in Figs. 2 and 3, the support block 7 is provided with two parallel bores 15 which extend horizontally therethrough, the forward end of these bores 15 being enlarged to provide counterbored sections 16 adjacent the front face 17 of the 5 block 7. The block 7 is secured in the recess 22 by means of screws (not shown) which pass through the bores 15 and engage threaded bores 20 provided in the rear face 10 of the recess 22. Obviously, if it is desired to change the support block 7 in order to adjust, for example, the rake angle of the cutter sections or to accom¬ modate cutter sections of various thicknesses, the support block 7 may readily be 0 removed from the recess 22 simply by unscrewing the screws from the bores 15 and sliding the block 7 out of the recess 22. A different support block may then be inserted into the recess 22 and secured in exactly the same manner. The cutter sections 9, 11, 12, 13 and 14 rest upon the flat, horizontal upper face of the support block 7, this face forming the support surface of the holder. As 5 best seen in Fig. 10, the cutter sections are each provided with a pair of flat contact faces along their side edges, and the contact faces of adjacent cutter sections lie OMP flat in contact with one another, so that the cutter sections are disposed in side-by- _side^ relationship. This side-by-side relationship is maintained by a first clamp in the form of two set screws 6, which are provided with external screw threads engaged with corresponding threads in bores provided in the forward end of the body portion 5. The set screws 6 are tightened by means of Allen keys engaged in hexagonal recesses in their outward ends until the cutter sections are clamped in position between the inward ends of the set screws 6 and the opposed face of the recess 22; it will be seen that the set screws 6 exert pressure on the cutter sections in a direction perpendicular to the contact faces of the cutter sections. The cutter sections are also held in position by means of a second clamp comprising a second clamp body member 4 having a cutter section contact surface 8 which contacts the upper face of the cutter sections. This surface 8 is provided with a seat of tough but deformable member such as polyurethane or copper which will conform to any slight differences in height among the upper faces of the various cutter sections. The second clamp body member 4 is also provided with a holder - contact surface 25 spaced from the cutter section contact surface 8 such that when, as shown in Fig. 1, the cutter section contact surface 8 is in contact with the upper faces of the cutter sections, the holder contact surface 25 rests against a surface 18 on the upper face of the holder body section 5. The surfaces 18 and 25 are provided with similar ridges and grooves which interlock, thereby reducing any tendency for the body section 4 to slide over the holder body section 5 because of, for example, vibration induced in the cutting tool during a cutting operation. The body member 4 is secured to the holder body section 5 by means of a screw 2 provided with a washer 3, which passes through an elongate slot 23 cut through the body member 4 and is engaged at its lower end in a threaded bore 19 provided in the upper face of the holder body section 5. The slot -23 allows the position of the body section 4 to be adjusted relative to the holder 5. As best seen in Fig. 7, the front face 24 of the body member 4 is beveled to provide chip clearance and to promote chip curling during cutting. It will be seen that when the body member 4 is held tightly against the upper faces of the cutter sections by the screw 2, the body member 4 exerts pressure on the cutter sections in the planes of the contact faces thereof and substantially perpendicular to the support surface on the upper side of the support block 7. The combined effect of the clamping forces exerted by the set screws 6 and the body member 4 on the cutter sections prevents relative movement between the various cutter sections and between the cutter sections and the holder, so that the various cutter sections form in effect a single cutter which acts on a workpiece in precisely the same manner as a conventional, one-piece cutter. To reduce any tendency for the cutter sections to slide toward the rear face 10 of the recess 22 during cutting operations, the space between the rear ends of the cutter sections and the wall 10 is filled with a liquid material, such as liquid steel, solder or some other suitable filling material, which is allowed to solidify and harden before the tool is used. After the tool has been used and if it is desired to reuse the holder body section 5 and the support block 10, the filler material by be hand ground out. However, more conveniently, the recess between the rear ends of the cutter sections and the wall 10 may be lined with a mold lining composition or with a plastic film to prevent adhesion of the filler material to the walls of the recess and a bore (not shown) may be provided through the body section 5 below the recess and a pin inserted through this bore to knock the filler material out of the recess after use. The cutter insert 9 is shown in more details in Figs. 8-10. As already mentioned, the front face of the cutter section 9 is beveled to provide proper clearance for the cutting edge thereof, the angle of this bevel being denoted ω in Fig. 9. Also, as shown in Fig. 10, another face of the cutter section 9 is beveled at an angle γ. It is intended that cutter sections such as the cutter section 9 be formed with varying angles ω and γ. The second cutter section 26 shown in Figs. 10 and 11, which can be substituted for the cutter section 9, is provided with a raised portion 27 on its upper face. When the cutter section 26 is used in the cutting tool shown in Fig. 1, the deformable material on the cutter section contact surface 8 will deform so as to completely surround the raised portion 27, thus preventing movement of the cutter section 26 relative to the support block 7 either toward the wall 10 of the recess 22 or parallel to the axes of the set screws 6. Provided the raised portion 27 is of adequate height, this may eliminate the need to provide filler material in the recess between the cutter sections and the wall 10. The second cutting tool of the invention, which is shown in Figs. 13 and 14 without its second clamp, is generally similar to the first cutting tool shown in Fig. 1 but has cutter sections which each comprise a tip 30, 31, 32, 33 or 34 brazed or otherwise rigidly affixed to a steel shank 39. As in the first cutting tool shown in Fig. 1, the holder has a body section 28 provided with a recess 35 having a rear wall 37 and relieved rear vertical edges 21. However, in the second cutting tool the portions of the holder body section 28 lying on either side of the recess 35 (which constitute, in effect, a pair of flanges extending upwardly above the support surface on opposed sides thereof) are provided with bores, and the shanks 39 of the cutter sections are also provided with similar bores. A dowel pin 36 is inserted through the bores in the bedy-section 28 and the shanks 39, thus fixedly locating the cutter sections in position and providing resistance to cutting forces which tend to force the cutter sections toward the rear wall 37 of the recess 35. The pin 36 is soldered to the body section 28 at 29 to prevent any tendency for the pin to slide out of the Jiores _5 ___a__se of vibration during cutting. Although not shown in Figs. 13 and 14, if desired a plurality of bores can be provided in each of the cutter section shanks, thereby enabling the cutter sections to be fixed in differing positions relative to one another and to the holder and enabling a large number of different shapes to be cut by the same selection of cutter sections. The third cutting tool of the invention shown in Figs. 15 and 16 is generally similar to that shown in Fig. 1 except that the body section 38 of the holder is substantially cylindrical in form and is provided with an axial bore 40 for attaching the cutting tool to the cross slide of a machine tool. As in the first cutting tool of the invention, the support surface for the cutter sections 9, 11, 12, 13 and 14 is provided by the horizontal upper face of a support block 7 which is seated in a recess 46 and attached to the body section 38 by screws 45. The second clamp of the third cutting tool is generally similar to that of the first and comprises a body member 41 provided with a cutter section contact surface 42 which, like the surface 8 in the first cutting tool, is covered with a layer of deformable material. The shape of the rear portion of the body member 41 differs, however, from the corresponding part of the first cutting tools; the rear part of the body member 41 is provided on its lower face with a hemieylindrical projection extending parallel to the axis of the bore 40, and this projection engages a corresponding recess provided in the adjacent part of the body section 38. The body member 41 is held in position by a screw 43. A part-cylindrical recess 44 is provided in the bddy section 38 above the body member 41 to enhance chip curling. Also, a recess 57 is cut in the upper part of the body section 38 to facilitate access by an operator to the screw 43. The third cutter section 47 shown in Figs. 17 and 18 has a flat lower surface 49 which contacts the support surface of a cutting tool of the invention. However, unlike the first and second cutter sections in Figs. 8-12, the third cutter section shown in Figs. 17 and 18 has grooves 48 cut in its upper surface, for reasons explained in the following paragraph. The second clamp body member 50 shown in Fig. 19 is generally similar to the body member 41 shown in Figs. 15 and 16, having a beveled front surface 51 and a substantially hemieylindrical projection 54 extending downwardly from the rear edge O PI of its lower surface. Also, like the body member 41 shown in Figs. 15 and 16, the body member 50 is provided with a vertical bore 53 passing therethrough to accommodate a clamping screw. However, the forward portion of the lower surface 52 of the body member 50 is not flat but instead is provided with transversely extending grooves. The body member 50 is used in conjunction with a shim 55, which is formed of deformable material and which has a beveled front surface 56, and with cutter sections similar to the cutter section 47 shown in Fig. 17 and 18. When the body member 50 is clamped in position in an assembled cutting tool, the grooves on its undersurfaee 52 are mechanically pressed into the upper face of the shim 55 while the lower face of the shim 55 is simultaneously pressed into the grooves 48 on the upper face of the cutter section 47. The deformable shim 55 conforms to the grooves on the body member 50 and the cutter section 47, thus helping to prevent movement of the cutter section relative to the body member 50 and to the tool holder. The beveled surfaces 51 and 56 allow room for chip curling. The fourth cutting tool of the invention shown in Fig. 20 is generally similar to that shown in Figs. 15 and 16, having a holder body section 58 of substantially cylindrical form and provided with an axial bore (shown in broken lines in Fig. 20). The second clamp body member 60 of this cutting tool is generally similar to the corresponding body member 41 shown in Figs. 15 and 16, except that the single central screw 43 has been eliminated, and instead the body member 60 is held in position by two screws 59 which pass through lugs on opposed horizontal edges of the body member 60. The fifth cutting tool of the invention shown in Fig. 21 has a holder body section 61 and a second clamp body section 62 which is of substantially U-shaped cross section. The actual clamping section 41 is not rigidly fixed to the body member 41; instead, a threaded bore is formed in the central part of the body member 61 and a threaded shaft 63 is engaged in this bore. By rotating the shaft 63 within the bore, the undersurfaee 42 of the clamping section 41 is forced against the cutter sections, which are thus, as in the previous cutting tools described, forced against a support surface provided on one side of a support block 7. Also, as in the cutting tools previously described, the cutter sections are held against one another by means of a set screw 6. The sixth cutting tool of the invention shown in Fig. 22 has an upwardly- extending L-shaped extension 64 provided on its tool holder body portion, this extension 64 having a vertical limb which extends upwardly to one side of the cutter section 9 and a horizontal limb which extends over the rear portions of the cutter O sections. A second clamp body member 66, which serves the same function as the body member 4 in Fig. 1, is ~ τeieasably secured to the horizontal limb of the ' extension 64 by means of a screw 65 which passes through an appropriately sized countersunk bore in the horizontal limb of the extension 64 and engages a threaded surface 67 of the body member 66 is which is similar to that provided on the surface 8 of the body member 4 shown in Fig. 1 and which engages the upper surface of the cutter sections. It should be noted that the body member 66 is made of trapezoidal cross-section, so that its upper surface is inclined at a slight angle to 0 the upper surfaces of the cutter sections; this helps to provide adequate clamping pressure. As in the cutting tools previously described, the cutter sections rest upon a support surface on the upper side of a support block 7 and are retained against one another in side-by-side relationship by means of set screws 6 (only one of which is visible in Fig. 22). 5 Fig. 23 is an underneath plan view of a second clamp body member 68 which is generally similar to the body member 50 shown in Fig. 19. However, the body member 68 has two elongate, plane surfaces 70 formed on the forward part of its lateral edges, these surfaces 70 lying above ridges 71 formed in the central part of the forward section of the body member 68. Like the body member 50 in Fig. 19, the 0 body member 68 is used with a shim of deformable material which in the assembled tool is clamped between the body member 68 and the upper surfaces of the cutter sections. The shim deforms to the shapes of the ridges 71 and the surfaces 70; this deformation of the shim helps to prevent any tendency for the shim material to move parallel to the ridges 71 under the forces experienced during cutting 5 operations. The body member 68 is provided with an elongate slot 72 similar to the slot 23 of the body member 4 shown in Fig. 6 and 7, and is also provided with a ridged heel 69 similar to the surface 25 on " the body member 4. Fig. 24 is a top plan view and Fig. 25 a side elevation of an apparatus for assembling cutting tools of the invention. This apparatus comprises a base plate 74 0 provided with counterbored apertures 75 through which pass cap screws 76, these screws 76 serving to secure the base plate 74 to a workbench or some other suitable, rigid support. On the flat upper surface of the base plate 74 rests a gauging apparatus 77 and a cutting tool support block 102. The support block 102 is provided with an adjusting wheel 95 by means of which it may be' moved transversely (i.e. 5 parallel to the axis of the wheel 95) across the base plate 74. A tool support block 94 is detachably secured, in any convenient manner, on top of the support block 102; the tool support block 94 shown is adapted to support cutting tools, such as that shown in Fig. _, having substantially cuboidal holder body sections, but the support block 94 can easily be replaced with one adapted to support 05 cutting tools, such as that shown in Figs. 15 and 16, which have cylindrical holders. The holder body section 96 of a cutting tool is secured to the upper face of the block 94 by means of a clamp 97. The cutting tool which is shown being assembled in Figs. 24 and 25 comprises, in addition to the holder body section 96, set screws 6, a support block 7 and cutter sections 9, 11, 12, 13 and 14 all of which are identical to 10 the similarly-numbered parts shown in Fig. 1, except that the front portions of the cutter sections extend upwardly in front of the forward edge of a shim 92. This shim 92 is identical in shape to the shim 55 shown in Fig. 19, while the second clamp body member 68 of the cutting tool has the form shown in Fig. 23. The second clamp body member 68 is retained in position by a screw 98 provided with a washer, 15 this screw and washer being identical in form to the screw 2 and washer 3 shown in Fig. L The gauging apparatus 77 is an electronic gauging apparatus provided with adjusting wheels 82, 85 and 88 which allow a prong 91 to be moved in three mutually perpendicular directions. The distance moved by the prong 91 as a result of 20 movement of the adjusting wheel 82 is electronically displayed in digital form, on a read-out screen 83 provided with a zero button 84. When the button 84 is pressed, the screen 83 is reset to 0, thus establishing an origin of movement along the axis controlled by the adjusting wheel 82. For obvious reasons, movement in one direction from this origin is thereafter indicated by a positive number on the screen 25 83, while movement in the opposed direction is indicated by a negative number. Similarly, the adjusting wheel 85 is provided with a screen 86 and zero button 87, while the adjusting wheel 88 is provided with a screen 89 and a zero button 90. In order that pressure may be imposed vertically on the cutter sections 9, 11, 12, 13 and 14, a ram support arm is provided having a vertical limb 101 extending 30 vertically upwardly from the base plate 74 and a horizontal limb 73 extending horizontally parallel to the upper surface of the base plate 74 above the cutting tool (the horizontal limb 73 of the arm is partially broken away in Fig. 24 and the vertical limb 101 is partially broken away in Fig. 25, in both cases for the sake of clarity). A hydraulic ram cylinder 99 extends downwardly from the horizontal limb 35 73 and is provided with a ram 100 having an end portion 93 which, as shown in broken lines in Fig. 24 is, rectangular in horizontal cross-section and extends across the hole of the cutting tooL The pressure exerted by the ram end section 93 on the cutting tool can be adjusted by an adjusting wheel 80 provided on the_gauging apparatus 77 adjacent the adjusting wheel- 82. A chart 81 listing recommended ram pressures for various shim materials is provided on the gauging apparatus adjacent the wheel 80. Once the ram pressure has be set by the adjusting wheel 80, the ream can be actuated by means of a thumb screw- 8= Fig-_ ).p__c ____loπ ~ the gauging apparatus 77. The tool assembly apparatus shown in Figs. 24 and 25 is used in the following manner. The second clamp body portion 96, with the support block 7 already fixed in position thereon, is clamped to the block 94 by means of the clamp 97. The cutter sections 9, 11, 12, 13 and 14 are placed on the support surface on the upper face of the support block 7 and the set screws 6 are tightened until the cutter sections are held loosely in side-by-side relationship but are still free to slide relative to one another. The relative positions of the various cutter sections are then adjusted by abutting the forward edge of each cutter section in turn against the prong 91, the position of the prong being adjusted by means of the adjusting wheels 82, 85 and 88 to produce the desired relative positions of the various cutter sections. (The apparatus shown in Figs. 24 and 25 have only a single prong 91, but obviously assembly of the cutting tools can be made more rapid by providing the apparatus with a plurality of prongs 91 movable relative to one another, so that the correct relative positions of all the cutter sections can be set in a single operation.) Once the cutter sections are in the correct relative positions, the set screws 6 are tightened to prevent further relative movement between the cutter sections. The shim 92 is then placed on top of the ridged section of the upper surface of the cutter sections and the second clamp body member 68 placed on top of the shim 92. The desired ram pressure is set by means of the adjusting wheel 80 and the thumb screw 78 operated to cause a downward stroke of the ram 100, thus pressing the ridges 71 on the body member 68 downwardly into the shim 92 and the shim 92 downwardly into the ridges provided on the upper faces of the cutter sections. The screw 98 is then inserted through the slot in the body member 68 into a threaded bore (not shown) provided in the holder body section 96 and tightened to secure the body member 68 in position. Together, the set screw 6, the shim 92 and the body member 68 prevent relative movement in any direction between the various cutter sections and the remaining parts of the cutting tooL The material used for the shim 94 will vary depending upon the forces exerted upon the cutting tool during the cutting operations. For light cuts in nonferrous materials, a copper or polyurethane shim is sufficient, but for heavy cuts in stainless steel a steel shim is recommended. Those skilled in the art of machine tooling can easily determine an appropriate shim material from their general knowledge of the relevant field or, in doubtful cases, by routine empirical tests. The fourth cutter inset shown in Figs. 26 and 27 is the presently preferred form of cutter insert to be used in the cutting tool of the invention. This cutting tool has transverse ridges 103 cut in the rear portion of its upper face and narrow, elongate flat surfaces 104 extending along either transverse edge of the cutter insert at either end of the ridges 103. The forward portion of the upper surface of the • insert extends above the surfaces 104 and is level with the top of ridges 103. When, as illustrated in Fig. 25, the cutter inset shown in Figs. 26 and 27 is assembled into a cutting tool incorporating a shim such as the shim 92 in Fig. 25, and pressure is applied to the shim, the shim with plastically deform around the ridges 103 and will seat against the flat surfaces 104, thus resisting movement of the cutter section in any direction. The seventh cutting tool of the invention shown in Fig. 28 has a holder body section 106 having a recess formed at the front end thereof, this recess being generally similar to the recess 22 of the holder body portion 5 shown in Fig. L A second clamp body member 105, which is generally similar to the body member 50 shown in Fig. 19 but lacks the ridges 52 thereof, is held in position by a screw 98 and clamps cutter sections 107. The cutter sections 107 are also held in position by set screws 6. However, unlike the cutter section shown in Figs. 26 and 27, the cutter sections 107 shown in Fig. 28 have a flat upper surface which mates with the flat under surface of the body member 105 and have ridges U0 on their lower surfaces. A shim 108 is positioned between the cutter sections 107 and a support block 109, which is generally similar to the support block 7 shown in Fig. 1 of somewhat reduced height. The support block 109 is held against the rear face 111 of the recess in the body section 106 by screws (not shown). The cutting tool shown in Fig. 28 may be assembled using the apparatus shown in Figs. 24 and 25 in the following manner. The support block 109 is secured within the recess in the body section 106 in the usual manner. The shim 108 is then placed on the support block and slid rearwardly within the recess until its rear face contacts the rear face 111 of the recess. In the cutting tool shown in Fig. 28, it is advisable to hold the shim 108 in position on the block 109 with adhesive during assembly of the apparatus; alternatively, the shim 108 could be secured in position with set screws similar to the set screws 6. The shim 108 should fit slideably within the recess. The cutter sections 107 are now. placed upon the shim 108, the set screws 106 loosely tightened, and the various cutter sections 107 adjusted to their correct relative positions using the prong 91. The set screws 6 are the rtϊghtened to prevent further relative movement between the cutter section 107, and the body member 105 pressed against the cutter sections 107 by the ram end portion 93. The screw 98 is 05 then tightened to hold the cutter sections inposition. Fig. 29 is a top plan viev ahtfFigr30 a-sϊde-elevat-on-αf a computer-controlled tool assembly apparatus of the invention. This apparatus comprises a housing 175 » supported on legs 174 (Fig. 30). A shaft 157 is mounted within the housing 175 for rotation about a vertical axis by a rotator 172, which can be a pneumatic, hydraulic, 10 electric or any other convenient type of rotator. The rotator 172 is provided with a measuring device (not shown) to measure its rotation and a locking means also not shown) whereby it may be locked in any desired position by a computer (not shown) which controls the operation of the rotator 172. The vertical shaft 157 carries four vertically-spaced tables 134, 135, 160 and 15 169, which rotate with the shaft 157. The upper two tables 135 and 160 are each provided with a plurality of cutter section storage stations 130, each of these stations storing a plurality of similar cutter sections. For example, one of the stations 130 stores cutter sections 127 having angled cutting edges, ' a second station stores cutter sections 128 having radiused cutting edges, a third station stores cutter 20 sections 129 having square cutting edges and a fourth station stores cutter sections 152 having stepped cutting edges. Each cutter section storage station 130 consists of a pocket having a rear stop surface, a side stop surface and a cutter section retainer in the ^ form of a plurality of small orifices located in the stop surfaces and connected to a vacuum line (not shown) which serves to hold the cutter sections in a 25 predetermined position in the pocket. It will be apparent to those skilled in the art that other methods of retaining the cutter sections in the pockets of the storage sections could be employed. The lower two tables 134 and 169 are provided with a plurality of holder body section storage stations 125 and 144 at which are stored tool holder body sections 118 30 and 14L The storage station 144, provided to store a cylindrical holder body portion 141 generally similar to that shown in Figs. 15 and 16, holds the body section 141 positioned on two dowel pins 143 and is also provided with a vacuum retaining means similar to that of the storage 130 previously described. The homing station 144 with the cylindrical body section 141 thereon can be slid radially outwardly, under the 35 control of the aforementioned computer, to an extended position in broken lines in Fig. 29 to deliver an assembled cutting tool including the body section 141 to the O PI window 162. Grinding wheel dressing tools 126 are also stored on the table 134. The storage stations 125 on the tables 134 and 169 are similar to the cutter section storage stations 130 on the tables 135 and 160 and are provided with a similar type of vacuum retaining means. The table 134 is also provided with second clamp body member and shim storage stations 131 and 132 respectively which house second clamp body members 119 and 142, together withthe shims 120. These stations are similar to the cutter section storage stations 130 previously described and are provided with the same type of vacuum retaining means. However, screw storage stations 133, provided on table 134 which store the screws 121 and 148, do not require a vacuum retaining means, since these storage stations are shaped to accurately retain the screws, which are simply held therein by gravity. The table 134 is also provided with a tool delivery and retrieval assembly which is capable of delivering an assembled tool at a window 162 (Fig. 30) or retrieving a tool which is inserted into the apparatus through this window. The delivery and retrieval assembly may be powered by any convenient pneumatic, hydraulic, electric or other drive means and is controlled by the aforementioned computer. Because of space limitations, the retaining means for retaining the various parts of the cutting tools at their storage stations is preferably the aforementioned vacuum system or a magnetic system; a magnetic retaining means can be used even though the cutting inserts themselves are not magnetic because the tool holder body sections, second clamp body members, shims and screws are normally made of magnetic material. The window 162, which is formed of a transparent material such as plexiglas, is mounted on 161 and is provided with a locking means (not shown) which locks the window closed to prevent tampering. The locking means is released by the computer when it is necessary to open the window to deliver or retrieve a tool. Positioned directly below the window 162 on the outside of the housing 175 is a shelf 146 supported by gussets 166. The shelf 146 is provided with a plurality of screw and dowel holes 147 into which can be inserted special purpose cutters which can be retrieved by the apparatus when they are needed for its operation. Although the apparatus shown in Figs. 29 and 30 has only one window 162 and one shelf 146, it may be advantageous to provide a plurality of such windows and associated shelves to facilitate entry of special purpose cutters into the apparatus. The tool assembly apparatus is provided with component transfer members in the form of automatic manipulators 117 mounted on supports 116. Each of the two manipulators 117 has a horizontal rotatable head 122, a vertical rotatable head 123 and grasping fingers 124. The manipulators 117 can travel along their supports 116 vertically and horizontally and can reach to all areas of the tables 134, 135, 160 and 169. Thus, by rotating the tables by means of the shaft 157 and moving the manipulators 117 on their supports 116, the fingers 124 of the manipulators can remove parts from, or return parts to, any of the storage stations on the tables. Each manipulator 117 is provided with a compressed air jet (not shown) for delivering a blast of compressed air, which is used in the manner described below. Within the housing 175 is also mounted a hydraulic ram assembly comprising a support member 138 having a vertical section and a horizontal section, a hydraulic cylinder 158 and ram having an end section 137 which can operate on a tool in exactly the same manner as the end section 93 shown in Fig. 25. Adjacent the ram assembly is a gauging apparatus 139 provided with a plurality of prongs 140; this gauging apparatus and prongs are generally similar to the apparatus 77 and prong 91 shown in Figs. 24 and 25 but are adapted for computer rather than manual operation. The support member 138 of the ram assembly and the gauging apparatus 139 are both supported on a structural member 163. This member 163 extends inwardly from one of the vertical walls of the housing 175, is supported by a gusset 167 and carries at its inward end a lateral support member 164 and a vertical support member 165, both these support members helping to support the periphery of the table 134. The lateral support member 165 provides resistence to the force imposed upon the table 134 when the hydraulic ram is operating. The tables " 134 and 169 are also provided with additional support members 168 extending inwardly from the vertical walls of the housing 175. In one corner of the housing 175 is mounted a grinding station which is controlled by the computer. This grinding station comprises a grinding wheel 115, a support member 112, a computer controlled manipulator arm 114, a coolant supply pipe 113 and an exhaust system 152. The manipulator arm 114 can, under the control of the computer, make all movements necessary to shape any form of cutting tools. A removable panel (not shown) is provided in the housing 175 adjacent the grinding station to facilitate access to the grinding wheel 115 so that grinding wheels of various forms can conveniently be installed at the grinding station. The exhaust system 152 removes from the housing 175 the dust particles inevitably generated during grinding operations. Coolant is supplied to the pipe 113 by means of a coolant reservoir 170 and coolant pump 171 which are shown only shematieally in Fig. 30. The grinding station is accessible to one of the manipulators 117 and also to a dressing tool 126 mounted on the table 134. A computer console 145 is disposed at the upper end of the housing 175. This console 145 includes a display screen 153 and various controls 154 for the computer. The provision of the necessary computer and software is believed well within the skill of those accustomed to working with numerically-controlled machine tools. Apart from the area covered by the console 145, the upper end of the housing 175 is closed by a removable transparent cover 155 made of a material such as plexiglass, the lower edge 156 of the cover 155 being attached to the housing 175 at a plurality of positions. The cover 155 allows the operator to check the operation of the tool assembly apparatus visually and also improves the aesthetic appearance of the apparatus. The tool assembly apparatus shown in Figs. 29 and 30 assembles a cutting tool of the invention in substantially the same manner as already described using the assembly apparatus shown in Figs. 24 and 25, except of course that the operation of the apparatus shown in Figs. 29 and 30 is controlled by the built-in computer and not manually. Each component required for assembly of the cutting tool is selected in turn from the storage station on the tables 134, 135, 160 and 169 by the manipulators 117 and is transferred to the assembly station 149 adjacent the hydraulic ram 158 and the guaging 139. As the manipulators 117 place each cutter section 136 in position on the support surface of the tool holder 118, a blast of compressed air from the air jet provided on the manipulator 117 urges the cutter section radially outwardly of the table 134 into engagement with the appropriate prong 140 on the guaging apparatus 139. When all the cutter sections have thus been assembled in their correct relative positions, the manipulators 117 tighten the set screws to retain the cutter sections in their correct relative positions. A shim 120 and a second clamp body member 119 are then placed on top of the cutter sections and the hydraulic cylinder 158 is operated to press the ram end section 137 downwardly onto the body member 119 to press the body member downwardly onto the shim 120 and the shim 120 downwardly onto the cutter sections 136. While the ram end portion 137 is still pressing down upon the body member, shim and cutter sections, a manipulator .117 retrieves a screw 121, positions it above the body member 119 and screws it into position, thus completing assembly of the tool. The ram is then retracted, as are the prongs 140, and the table 134 is rotated 90 degrees clockwise (in Fig. 29) by the shaft 157 until the assembled tool is adjacent the window 162. The tool is then slid radially outwardly of the table 134 and delivered at the window 162, which is automatically unlocked so that the operator can retrieve a tool from the window. O PI Should non-standard components be required for assembly of a particular tool, these non-standard components are placed on the shelf 146 by the operator and picked up from this shelf at the appropriate time by one of the manipulators 117. The tool assembly apparatus is also capable of disassembling tools inserted through the window 162 by the operator, the disassembling operation being substantially the reverse of the assembly operation except that, of course, it is not necessary to use the prongs 140. Should a tool need resharpening after use, the operator places the tool on the shelf 164 and the assembly will then pick up the worn tool, transfer it to the grinding station, perform the necessary grinding operations thereon, and redeliver the sharpened tool to the window 162. It will be seen that the automatic tool assembly apparatus shown in Figs. 29 and 30 has several advantages: L Since a cutter section can be used in a plurality of different grinding tools, the quantity of expensive tool materials which must be kept in stock is reduced; 2. Similarly, since the tool holders can be retrieved from tools when the tools are dismantled after use, separate tool holders are not required for each tool, and the number of tool holders which must be kept in stock is reduced; 3. Where one cutter section wears more rapidly than the others during cutting operations, the tool can be made ready for further use by simply replacing the worn tool section, whereas in a conventional integral cutting tool the whole tool must be replaced; 4. Since the cutter sections are fastened in position by clamping, the costly brazing operations hitherto necessary to fix tools in holders are e- liminated; 5. Since the cutting edges of the cutter sections are accurately positioned by the prongs 140 each time a new cutting tool is assembled, wear on the cutter sections which may have occurred as a result of previous use is automatically compensated for; 6. If a particular cutting tool becomes obsolete or needs to be redesigned, the expensive tool material therein can be reused in other cutting tools, whereas when a conventional integral cutting tool becomes obsolete it must be completely scrapped; 7. The computer of the tool assembly system can be used to keep track of the number of machine hours for which a particular cutting tool is used, O PI and to indicate to the operator when the tool should be returned to the assembly apparatus for sharpening; 8. Since the configurations and each step necessary to produce each completed tool can be stored in the memory of the computer, drawings 05 of each tool are not required and changes, revisions, deletions or additions to a stock of standard cutting tools can be rapidly achieved simply by reprogramming of the computer; 9. The tool assembly apparatus requires less inventory space and provides better tool control than prior art systems, since all tools are produced - 10 and disassembled at one location, and in addition tools can be assembled more quickly than they could be pulled from storage manually, thus eliminating problems caused by misplaced tools. The eighth cutting tool of the invention shown in Figs. 31-33 is generally similar to that shown in Fig. 28 and has a tool holder formed in two sections, namely 15 a body section 176 and a support block 189. However, in the eighth cutting tool shown in Figs. 31-33 the support block 189 is substantially hemieylindrical in form and is accommodated within a part cylindrical recess in the front end of the body section 176. A clamp pin 180 passes through oversized bores in the body section 176 and through a closely fitting bore in the support block 189, thus allowing the support 20 block 189 to pivot relative to the body section 176 about the axis of the pin 180. The support block 189 may be locked in position relative to the body section 176 by inserting two clamping screws 179 through counterbored apertures provided in the body section 176 adjacent the recess therein and engaging these screws with threaded bores extending half way through the pin 180. When the screws 179 are 25 loosened, the oversized hole in the body section 176 which accommodates the pin 180 allows the support block 189 to be adjusted to a positive or negative rake angle. To inhibit relative rotation between the support block 189 and the body section 176, ridges 190 are provided on the cylindrical surface of the support block 189 and these engage similar ridges provided on the cylindrical portion of the surface of he recess 30 in the body section 176. The upper surface of the support block 189 is provided with ridges 191 and with two parallel vertical lugs 184 arranged on opposite sides of the support block 189. A pivot 185 passes through horizontal bores provided in the lugs 184 and through a bore passing transversely through a second clamp body member 178, which is thus 35 pivotally mounted on the support block 189. The body member 178 is provided at its rearward end with a clamping screw 176 equipped with a lock nut 187. In this cutting tool, clamping of cutter sections 181 and a shim 182 lying beneath the cutter sections 181 against the support block 189 is effected by screwing the clamping screw 189 downwardly until the lower end thereof engages the bottom surface of a rearward extension 177 of the recess in the body section 176. When the clamping screw 186 has been turned to the proper clamping position, it is then locked in position with the lock nut 187. To secure the cutter sections 181 in position before they are clamped, set screws 183 are provided engaged in threaded bores in the body section 176. Fig. 33 shows the eighth cutting tool of the invention at a 5 β positive back rake angle. Commercially available tool holders with wedge arrangements or shims can be used if desired to maintain the center line of the tooL The fifth cutter section 193 shown in Fig. 34 has two cutting edges 194 at opposed ends thereof. The upper surface of the cutter section 193 is provided with a central raised portion 192, the distance (designated "A" in Fig. 34) from the raised section 192 to each cutting edge 194 being the same. The cutter inset 193 is used in a cutting tool with a shim engaging the raised portion 192, which thus has the same function as the ridges 103 provided on the cutter section shown in Figs. 26 and 27, namely preventing relative movement between the various cutter sections in the tool and between the cutter sections and the tool holder. Should one cutting edge 194 of the cutter section 193 become chipped or otherwise damaged in use, the operator can quickly disassemble the tool, turn the cutter section 193 around so that the other cutting edge is presented to the work piece and reassemble the tool, whereupon the raised portion 192 will re-enter the pocket already formed in the shim, thus setting the new cutting edge 194 accurately in position relative to the remaining cutter sections. Fig. 35 shows part of a cutting tool of the invention in which a cutter section 197 rests upon a support surface within a recess in a tool holder 200, this recess having a rear wall 199, and a shim 195 is being lowered onto the cutter section 197 to clamp it in position. The cutter section 197 has a "raised portion" 196 on its upper surface, this "raised portion" 196 actually being formed by cutting two parallel grooves 198 in the upper surface of the cutter section 197. The shim 195 has a downwardly extending projection thereon which fits between the vertical walls of the grooves 198 remote from the raised portion 196, the depth of the projection on the shim 195 being equal to the depth of the grooves 198. Thus, the shim 195 conforms to the raised portion 196 in the same manner that a shim conforms to the raised portion 192 of the cutter section shown in Fig. 34. When the shim 195 is clamping the cutter section 197, the rear vertical face of the shim 195 abuts the rear wall 199 of the recess in the tool holder 200; this helps to prevent movement of the cutter section 197 toward the wall 199 during cutting operations. The cutter section 197 shown in Fig. 35 has the advantage over the cutter section 193 shown in Fig. 34 that less grinding is required to cut.the grooves 198 than is required to cut away the upper face of the cutter insert 193 to produce the raised portion 192. Also, during use, the front end of the shim 195 lies below the plane of the cutting edge of the cutter insert 197, thus eliminating chip clogging between the shim 195 and the cutter section 197. The cutter section 203 shown in Fig. 36 is generally similar to the cutter section 193 shown in Fig. 34 and has a raised portion 201 on its upper surface. However, the cutter section 203 has a sloping surface 202 cut therein to provide a rake angle. It will be apparent to those skilled in the art that a positive, negative or neutral rake angle can be ground at either end of the cutter section 203 and that the angles at the two ends of this cutter section can be the same or different. Fig. 37 is a partial side elevation of a cutting tool of the invention. This cutting tool has a tool holder 206, a cutter section 205, which is generally similar to the cutter section 193 shown in Fig. 34 but which lacks a raised portion on its upper surface. A shim 204 rests on the upper surface of the cutter section 205 with its rear vertical face abutting the rear wall 208 of the recess in the tool holder 206. During assembly of the cutting tool, the shim 204 is forceably pressed downward upon the cutter section 205 and the deformable material from which the shim 204 is made will deform downwardly into the cavity 207 to the rear of the cutter section 205. This deformation of the shim 204 into the cavity 207 provides an extension of the shim 204 extending downwardly behind the cutter section 205, and this downward extension resists any tendency for the cutter section 205 to move rearwardly toward the wall 208 during cutting operations. As discussed above with reference to Fig. 1, the cavity 207 may be filled with liquid steel or other filler material which is allowed to solidify before the tool is used, the filling of the cavity 207 providing additional protection against movement of the cutter section 205 toward the wall 208 during cutting operations. When the cavity 207 is to be thus filled, it is advantageous to slope the walls of the tool holder 206 surrounding the recess so that the recess narrows downwardly and to provide the tool holder 206 with a knockout pin extending upwardly through the tool holder to the base of cavity 207 so that the filler material may be knocked out after use of the cutting tool has terminated, thereby allowing reuse of the cutting tool components. Also, as discussed above with reference to Fig. 1, to facilitate removal of the filler material from the cavity 207 it is advantageous to line this cavity with a plastic film such as polyethylene or with a commercial mold lining compound to prevent the filler material sticking to the walls of the cavity 207. Fig. 38 shows a cutter section 211 having a raised portion on its upper surface, 05 and a shim 209 which is used in conjunction with the cutter section 211. The lower face 210 of the shim 209 is covered with an adhesive coating so that the cutter section 211 will not fall away from the shim 209 when the shim is removed from a tool holder during disassembly of a tooL This allows replacement cutter sections to be more readily installed and generally facilitates handling of cutter sections, 10 espeeially small or narrow cutter sections. The arrow in Fig. 38 indicates the direction in which the shim 209 should be pressed against the upper face of the cutter section 211 in order that the shim will conform to the shape of the raised portion on the upper face of the cutter section 211. The cutting tool of the invention shown in Fig. 39 comprises a tool holder body 15 portion 216, the front end of which is provided with a recess having a sloping lower surface 217. Cutter sections 215, which are identical in form to the cutter section 193 shown in Fig. 34, rest upon the surface 217 and are retained in position by a shim 214, a second clamp body member 213 and a clamping screw 212. The slope of the surface 217 provides a rake angle on the cutter section 215 without the need to grind 20 the rake angle on the cutter section itself. The shim 214 extends parallel to the sloping surface 217 and the rear wall thereof is cut to match the rear wall of the recess to provide a seat to resist movement of the cutter inset 215 toward the rear wall of the recess. The surface of the body member 213 in contact with the shim 214 slopes to match the inclination of the shim 214. Obviously, the surface 217 can be 25 sloped to provide a positive, negative or neutral rake angle on the cutter sections 215. The cutting tool shown in Fig. 40 provides a rake angle without cutting a sloping surface at the base of the recess. In the cutting tool shown in Fig. 40, the tool holder is in two sections, namely a body section 222 and a removable member 30 221 which although not shown in Fig. 40) is releasably secured to the body section 222 in any convenient manner. The removable member 221 is wedge-shaped, having a horizontal lower surface in contact with the body section 222 but a sloping upper surface in contact with cutter sections 220. The cutter sections 220 are retained in position by a shim 219 and a second clamp body member 218. The use of a removable 35 member 221 rather than the sloping surface 217 shown in Fig. 39 has the advantage that the rake angle of the cutter sections 220 can readily be changed by replacing the removable member 221 with another removable member having a different angle of inclination of its upper surface. In the cutting tools so far described, the tool holder has always extended in a straight line from the cutter sections. However, to meet special cleaι_ance requirements where the nature of the workpieee does not permit the use of a straight holder, the tool holder may be offset or angled. For example, Fig. 41 shows cutter sections 223 mounted on a laterally offset tool holder 225. Obviously, the tool holder may be offset either to the right or to the left depending upon the nature of the workpieee being operated upon. Fig. 42 shows cutter sections 224 mounted on a tool holder 226 extending at an angle to the length of the cutter sections 224. Again, obviously the tool holder 226 may be angled either to the right or to the left; angled tool holders have a variety of advantages especially when used in conjunction with computer numerically-controlled turning centers. In addition to offsetting or angling the tool holder, the size and shape of the tool holder may be varied to meet the requirements of various machine tools. A tool holder of round cross-section is useful in machine turrets for facing and grooving operations. The cutting tool of the invention shown in Fig. 43 has removable side pieces 230 retained in position by screws 229. The cutting tool also comprises cutter sections 227 held in position by a set screw 228. The cutter sections 227 are assembled with the side pieces 230 in position as shown in Fig. 43 and the set screw 228 is tightened. A shim is then placed on top of the cutter sections 227 and pressed downwardly thereon as previously described. Thereafter a second clamp body portion is placed on top of the shim and tightened to clamp the shim downwardly upon the cutter sections 227. The side pieces 230 may now be removed after unscrewing the screws 229 leaving the cutter sections 227 held in position by the clamp body member and shim alone. This enables the cutting tool to be used in areas where only a very small clearance is available. Instead of pressing a shim down onto a cutter section as shown in Fig. 38 a shim may be molded around raised portions on the cutter sections, such as the raised portion 192 shown in . Fig. 34. When the shim is allowed to harden, it acts in the same manner as a shim that has been pressed down upon the cutter sections.

Claims: CLAIMS 1. A cutting tool comprising a cutter having a cutting edge, a holder (5, 7; 28; 38; 58; 61; 64; 96; 106; 149; 176, 189; 200; 206; 216; 221, 222; 225; 226; 230, 23l)for the cutter and a means (2, 3, 6; 36; 41, 43; 50; 62, 63; 65, 66j 68; 98; 105; 178, J.86, 187; 212, 213; 218) for retaining the cutter in the holder, characterized in that: 05 the cutter comprises a plurality of separate cutter sections 9, 11, 12, 13, 14; 26; 30, 31, 32, 33, 34, 39; -49; 107; 181, 182; 193; 197; 203; 205; 211; 215; 220; 223; 224; 227) each cutter section having a cutting edge (194; 197); the holder has a support surface (188; 217) against which the cutter sections can lie; and 10 the retaining means comprises a cutter sections retainer (2, 3, 4, 6; 36; 41, 43; 50; 62, 63; 65, 66; 68; 98; 105; 178, 186, 187; 212, 213; 218) capable of retaining the cutter sections on the support surface in side-by-side relationship so that the cutting edges of all the cutter sections can all be applied to a single workpieee, the retainer being capable of preventing relative movement between the various cutter 15 sections and between the cutter sections and the holder. 2. A cutting tool as claimed in claim I, characterized in that each cutter section is provided with a pair of flat parallel contact faces on opposed sides of the cutter section, such that, when the cutting tool is assembled with the cutter sections disposed side-by-side the contact faces of adjacent cutter sections lie in 20 contact with one another, and in that the retainer comprises a first clamp (6; 183; 229) capable of exerting pressure on the cutter sections in a direction substantially perpendicular to the contact faces thereof, thereby holding the cutter sections in side-by-side relationship, and a second clamp (2, 3, 4; 41, 43; 50; 60, 41, 62, 63; 65, 66; 68; 98; 105; 25 119; 178, 186, 187; 212, 213; 218) capable of exerting pressure on the cutter sections in a direction substantially in the planes of the contact faces and substantially per¬ pendicular to the support surface. 3. A cutting tool as claimed in claim 2, characterized in that the second clamp comprises a second clamp body member (4; 41; 50; 60; 66; 68; 105; 119; 213; 218) 30 having a cutter section contact surface (8; 42; 67; 70, 71) and a holder contact surface (25; 54; 69) spaced from the cutter section contact surface such that when the cutter section contact surface contacts the cutter sections, the holder contact surface contacts the holder, the second clamp body member being provided with a securing device (2; 43; 59; 63; 65; 98; 212) whereby it may be releasably secured to the holder. 4. A cutting tool as claimed in claim 2 characterized by a shim (55; 181; 195; 05 204; 209; 214; 219) of deformable material capable of being interposed between the cutter sections and the surface of the second clamp in contact therewith. 5. A cutting tool as claimed in claim 1 characterized in that the holder is provided with at least one stop surface (10; 37; HI) capable of abutting a cutter section at a point remote from the cutting edge thereof, such that the abutment of 0 the stop surface against the cutter section helps to prevent movement of the cutter section away from a workpieee when the cutting edge of the cutter section engages the workpieee. 6. A cutting tool as claimed in claim 1 characterized in that the holder comprises a body section (176) and a movable section (189) pivo tally mounted on the 5 body section and capable- of being reasonably secured to the body section in any one of a plurality of differing positions, and in that the movable section carries the support surface so that the rake angle of the cutting edges of the cutter sections (181) can be varied by pivoting the movable member relative to the body member. 7. A- cutting tool as claimed in claim 1 characterized in that the holder 0 comprises a body section (5; 38; 96; 106; 222) having a recess (22; 46) therein and a removable member (7; 109; 221) at least part of which can be accommodated in the recess, in that the support surface is carried by the removable member, and in that the retainer, when retaining the cutter sections on the support surface, also retains the removable member fixed in position relative to the body section. 5 8. A cutting tool as claimed in claim 1 characterized in that the holder is provided with a pair of flanges extending upwardly above the support surface on opposed sides thereof, in that apertures are provided passing through these flanges and through the cutter sections, and in that a pin (36) is provided capable of being inserted through the apertures in the flanges and the cutter, sections so as to prevent or at least restrict relative movement between the cutter sections and the holder. CMPI -28- 9. A cutting tool as claimed in claim 1 characterized in that the cutter sections, the holder and the cutter sections retainer are shaped so that, when the cutting tool is assembled, a cavity is left adjacent the end of the cutter sections remote from the cutting edges thereof, the cutting tool also being characterized in 05 that it comprises a filler material which can be inserted into the cavity in flowable form and wiE thereafter harden to form a stop which engages the ends of the cutter sections remote from the cutting edges thereof. 10. A cutting tool as claimed in claim 2 characterized in that each of the cutter sections bears at least one raised portion (27; 48; 103; 110; 192; 196; 201), which in 10 the assembled tool, lies adjacent either the support surface or the second clamp, the cutting tool also being characterized by a shim (55; 92; 108; 188; 195; 209; 214; 219) capable of being placed between the raised portion and the adjacent portion of the support surface or the second clamp, the shim being provided with, or being capable of being deformed to form, at least one recess accommodating the raised portions of 15 the cutter sections. 1L A tool assembly apparatus characterized by being capable of assembling a cutting tool as claimed in any one of the preceding claims and by comprising: a plurality of cutter section storage stations (130) each capable of storing at least one cutter section; 20 a holder storage station (125, 144) capable of storing at least one holder; a retainer storage station (131, 132, 133) capable of storing at least one retainer; and a component transfer member (117) capable of transporting the cutter sections, the holder and the retainer from their respective storage stations and 25 assembling them to form the cutting tooL 12. A tool assembly apparatus as claimed in claim 11 characterized by a grinder (115) capable of sharpening the cutter sections, the component transfer member being capable of transporting cutter sections to the grinder for sharpening.

Inventors: GARDNER JAMES JOSEPH, GARDNER, JAMES, JOSEPH
Applicants: GARDNER JAMES JOSEPH, GARDNER, JAMES, JOSEPH
Application year: 1982
Main classification: B23P21
IPC codes: B23B27, B23P11