Nov. 26,1946. T. R. GOLDSMITH 2,411,784‘ ‘ MILLING CUTTER Filed Nov. 30, 1942 s Sheets-Sheet 1 ' INVENTOR I Nov. 26, 1946. ' T. R. GOLDSMITH ' MILLING CUTTER ‘ ' 2,411,784 ' ’ ~ Filed Nov. 30, 1942 SSheets-Sheet 2 /#4 é“ "w tka _v_- ___ E» ’ 'INVENTOR 720mg: 72 62Z/sméZ/2 - Y ' ‘ ATTORNEYS Nov. 26, 1946. "r. R. GOLDSMITH MILLING CUTTE‘R 2,411,784 Filled‘ Nov; 50, 1942 3 Sheéts-Sheet 5 ATTORNEYS. 2,411,784 Patented Nov. 26, 1946 UNITED STATES PATENT OFFICE 2,411,784 MILLING; CUTTER Thomas Ralph Goldsmith, Bu?'alo, N. Y., a-s-‘ ' signor, by mesne assignments, to Super Tool Company, Macomb County, Mich., a partner ship composed of Mrs. Sophie Birgbauer, Mrs. Ruth Schreck, Mrs. Gordon Birgbauer, and Mr. Gordon Birgbauer Application November '30, 1942,,’ Serial No.’ 467,327.‘ . 3 Claims. (01. 29-103) ’ 2 1 - ‘This invention relates to tools of the milling 7' ' lowing description taken in conjunction with the accompanying drawings, wherein: cutter type, and particularly to'a built-up milling cutter having the cutting edges tipped with hard enedrcutting material in a manner to simplify the grinding .of the cutting edges. Figure 1 is an end view in elevation of a see mental cutting tool having tipped teeth which embodies a feature of the present invention; Fig. 2 is a side View of the tool illustrated in Fig. 1, as viewed from the line 2-‘—2 thereof; Fig. 3 is an exploded view of the cutter illus_ > While no particular problem is presented in tipping the cutting edges. of tools with a hard cutting material, such as tungsten vcarbide, ti trated in Fig. 2, showing the various segments tanium carbide, Stellite; and the like, nevertheless the tipping of milling cutting tools having form 10 thereof; Fig.4 is an end-view in elevation of a cutter, cutting ‘edges has not been successful because of similar to that illustrated in Fig. 1, showing a the dii?culty in sharpening the tools after the further form which the invention may assume; edges become dulled. When a dove-tail, for ex~ Fig.5 is a side view of the cutter illustrated ample,-is to be cut in a' work-piece, the‘ cutter will havea pair of offset flat cutting edges joined 15 in Fig. 4, as viewed from the line 5-5 thereof; Fig, 6 is an exploded view of the elements of by a sloping cutting edge which presents a dim the cutter illustrated in Fig. 5; cult grinding problem when the cutting edges be come dull and require sharpening. ~ ' Fig. 7 is an end view in elevation of a tipped ' cutting tool, similar to that illustrated in Fig. 1, It is substantially impossible to grind the slop ing edge without harming the spaced parallel 20 showing a still further form of the invention; Fig. 8 is a side View of the tool illustrated in edges or topreform the face of a grinding wheel Fig. '7, as viewed fromthe line 8-8 thereof; and to produce the form grinding of the edges. ' The Fig. 9 is an exploded view of the tool illus problem of grinding form cutting edges of ‘milling trated in Fig. 8. ' cutting tools is such a di?icult one that tipped milling cutterswere never, to applicant’s knowl 25 Referring to Figures 1 to 3, a cutting tool II is illustrated embodying. a central cutting seg edge, constructed for commercial application. Similarly, when an arcuate slot having ?at shoul ders adjacent thereto is to be out in a workpiece ment l2 and end segments l3 and I4. The tool , H is employed for cutting a slot I5 in a piece of being machined, it was found impossibleto grind metal It, as illustrated in Figure 2. The slot has a central arcuate portion l6 and adjacent ?at shoulder portions l1 and I8. When the entire tool was made from a hard cutting materiaLit . the arcuate and shoulder portions ofvthe tool without deforming ‘one or all of the edges. It is one object of the present invention to so construct a milling cutter that the di?iculty in grinding the cutting edges is‘ entirely overcome. . It, is a further object of the invention to divide a milling cutter for producing an irregular sur face into cutting segments having teeth of a form which are readily ground and which when assem was found that several sharpenings a day were required to retain a sharp enough edge to cut the ‘ slot l5 in continuous production. bled produce the irregular surface desired. It is a still further object of the present in vention to divide the cutter into several cutter segments and to shim the segments apart to retain the width ‘to the cutter after the sides have been ground when performing a sharpening op 40 In view of the fact that the setting up of the tool required considerable time, a material loss in production resulted therefrom. When attempting to apply a hardtip to the cutting edges it was found that it wasfsubstantially impossible to grind the arou ate and flat forms on the tool to any degree of precision "and satisfaction. It was found that the tools could be made up from segments with the teeth of each segment having a simple form which 45 could be readily ground so that the di?iculties ex perienced in sharpening the tipped tool were A still further object .of the invention is to thereby overcome. , employ a plurality of cutter segments with spaced .. .Reierringmore particularly‘ to Figure 3, it will teeth which interlock with each other and over be seen that'the central segment l2 has a body come the effect of employing a reduced number portion 2! which is recessed at 22 and 23 inward of; teeth byincreasing the speed of rotation of the ly of the width of the teeth 24. The teeth 24 have an arcuate surface 25 conforming to the-shape of Other objects and vfeatures of novelty of the eration. cutter. , ' - ~ - “ i > ‘ ' the arcuate portion N5 of the slot l5 to be out by thetool. A tip 26 which is preferably made invention will be either speci?cally pointed out or will become apparent when referring, for a' better understanding of the invention, to the fol: 55 .°?C?1”PQ19Y.°1' other extremely. hard materials 2,411,784 4 be made by each cutting tooth than by the cut ting teeth of tools which are not tipped by the hardened material. Spacers 45, 46, and 41 sepa rate the cutter segments 33, 34, t5 and 36 from each other. It will be noted from. Figure 4 that all of the teeth [-59 of the segments haveC'arboloy sweated on the ends of the teeth 25, as illustrated more particularly in Figure l. The arcuate sur face 25 is then ground on the teeth with a desira ble relief. The tool segments It and M nest withinthe recesses 23 and 22, respectively, of the central tool segment H. The tool segments is and [4 have teeth 2'3 which are provided with the tips of Car or similar tips 5! disposed in a recess in the end thereof in position to be employed as the portion having the cutting edges. boloy 28 or other material as clearly disclosed in Figure 1. No problem is presented in sharpen 10 Referring to Figures '7 to 9, a cutter 52 is illus ing the teeth 13 and Ill since they have ?at sur trated, made up of cutting segments 53 and 54. faces at the ends and sides. After the teeth have As illustrated in Fig. 8, the cutter 52 is employed been sharpened, the segments are clamped to for cutting a dove-tail slot 55 in a piece of metal. gether, as illustrated in Figure 2, to provide an It will be noted that the parallel surfaces 56 and over-all cutting contour of a form to cut the slot 15 51 are spaced from each other and joined by a l5 in the metal I 6. sloping cutting edge 58. t Was found substan If it is found that by dressing the side faces tially impossible to grind the sloping surface 58 of the segments 53 and M that the over-all di of the hard tip material without interfering,r with mension of the slot l5 has been reduced, shims or destroying the surface on the parallel edges may be provided between segments l3 and I4 and 20 55 and 51. By separating the two segments 53 the body portion 2! of the central segment I2 to and. 54, it will be ‘seen that the‘ sloping cutting obtain the desired width. It was found that a edge 58 may be ground without interference with tool made in this manner could operate continu the end cutting edge .51 and that this can be ously throughout a 24 hour day without requiring readily done without reouiring a lengthy set-up a sharpening operation. When the cutting edges 25 or the use of a preformed grinding face. This is become dull, it is a simple operation to grind the also true of the segment 53 having the straight cutting edges. ends and sides of the teeth 21 of the cutter seg ments l3 and Hi and to grind the sides and the The teeth 59 of the segment 53 are provided arcuate surface 25 of the central segment 12. with a Carboloy tip 6! while the teeth 62 of the These may again be assembled on a key 3! on the 30 segment 54 have similar tips 63. Each segment is provided with three teeth and the fact that only arbor 23 and be retained in abutted relation by the sleeves 32 in the conventional manner. three cuts are taken during one revolution of the arbor 29 has no bearing on the speed of opera In Figures ll, 5, and 6, a bank of milling cutter tools is illustrated for cutting a plurality of slots tion of the cutter in view of increased speed of in the workpiece. Cutter segments 33, 34, 35, and 35 rotation of the arbor 29 and the depth of out which may be taken because of the extremely 3% are similar to the cutter segments 53 and Ill of Figures 1 to 3. The cutter segment 36 is of great hard tips on which the cutting edges are formed. er diameter to cut a slot Ell of greater depth than the slots 38, 39, and iii cut by the segments 35, 34, and 83, respectively. The slot 39 has a shoul der d2 cut thereon by a cutter segment 43 of smaller diameter than the segment 34 with which the cutter nests. The segments 33, 34, 35, and 36 of the cutters are undercut at M to receive other cutter seg ments when wider slots are to be cut in the ma Preferably each segment sbould'l'lave an even number of cuttinrr teeth so that they can be ac curately measured diametrically across the seg ment. When an odd number of teeth are pro vided. as illustrated in Figure '71 di?iculty is ex perienced in accurately measuring the radii of the teeth. 45 While a dove-tail slot is illustrated in Figure 7 and an arcuate flat shouldered slot in Figure 2, terial. t will be noted that the cutter segment as Well as spaced slots in Figure 5. it is to be un 53 nests within the recess 134 of the cutter seg derstood that any combination of segmental cut ment 5:2 so as to be capable of being sharpened ters having tipped teeth may be employed to pro and being shimmed outwardly so that the width 50 duce any shape of slot or surface. This is pos of the slot 39 and shoulder 44 may be main siblewhen each of the segments has been selected tained. It is to be understood that the cutter to have teeth with cutting edges which may be segment 63 may be of the same diameter as the ground directly by a standard grinding wheel segment 3d so as to cut the same depth of slot 39 without the necessity of preforming the face thereof. Width to the slots is maintained by the slot when the two segments are shimmed shims which space the segments apart a distance apart after the side faces have been ground to equal to the amount of material ground from the produce a sharpening operation. side faces during a sharpening operation. The It will be noted that each of the segments 33, 3d, 35, 36, and 43 are provided with four teeth 60 interlocking of the segments permits the in creased spacing of the segments without a gap where at least 8, H), or l2 teeth would be pro’ appearing at the overlapped cutting edges. With vided in a normal cutter. This eliminates the this invention, tipped milling cutters may be made difficulty of presenting a Wheel to the cutting up from a plurality of cutter segments to pro edges for the grinding operation, and reduces the duce any desirable form in a slot or surface milled number of cuts being taken in the slots during by such cutters. While the number of teeth on each revolution of the supporting arbor 29. To each segment is materially reduced over that overcome this tendency of reducing the speed of normally employed to simplify the grinding and the cutting operation, the rotation of the arbor sharpen-operation, no time is lost thereby as the Ed is increased to make up for the loss of teeth in each cutter so that the same number or more 70 decrease in number of teeth is overcome by the increased speed of operation of the supporting cuts are made by the teeth in the slot in the same length of time. arbor. The hardened tips on the teeth retain their cutting edges for a considerably longer The tipped tool retains its cutting edges for a greater length of time in view of the hardness of period than the teeth of solid milling cutters the material so that a greater depth of out can 75 made from ‘tool steel and are capable of cutting while being capable of maintaining the Width of 2,411,784 ‘ 5 6 faster and at a greater depth 50 as to reduce the when the body portions are assembled together time required to machine the slot or surface. and the teeth on one'of said portions being dis It is to be understood that, where the word “Carboloy” is employed throughout the descrip placed‘ axially into overlapping position with re spect to the teeth on the other portion to provide a driving interlock between the portions. 2. A cutting tool including, in combination, a pair of like cutting elements having a body por tion and spaced circumferential teeth, the teeth tion, the invention is not to be considered as being limited to tungsten carbide tips but that titanium carbide, Stellite, and other hard mate rials may also be utilized. . It will also be noted on one element overhanging the right-hand face that the interlocking cutting elements may be constructed exactly alike and thereafter have the 10 of its body portion, the teeth of the other element overhanging the left-hand face of its-body por body relieved, one on the right side, the other on . tion, the arcuate length of the teeth being equal the left side, or, when a third cutter is to be nested with the two cutters, to have the relief to that of the space therebetween, so that, when the adjacent faces of the elements abut, the teeth cut on both sides of the body thereof. When of the elements are in overlapping and interlock‘ the cutters are nested together, the teeth thereof ing relation to each other. ' will overhang and will'interlock relative to each 3. A composite milling cutter made of two other, so that one may be driven by the other when one is threaded on an arbor, as illustrated washerlike body portions, each having cutting teeth thereon, the cutting teeth on one of said in Figs. 8 and 9. The space between the teeth and that provided by the position of the teeth to 20 portions being spaced circumferentially from those on the other a su?icient amount tov permit cut alternate sides of a slot provides large areas the teeth of one portion to be positioned between ‘ for chip clearance which prevents the tearing of the teeth of the other portion when the body the walls of the slot and damage to the cutter portions are assembled together, the teeth on one teeth. portion being axially overlapped with respect to What is claimed is: 1. A cutting tool of the milling type having a the teeth of the other portion and received in circumferentially spaced recesses in the side of pair of washer-like body portions each portion provided with peripheral cutting teeth, the teeth said other portion to forma driving interlock, ' said recesses being located radially inwardly of on one of said body portions being spaced circum ferentially from those on the other a sufficient 30 the cutting edges of the body portion in which amount to permit the teeth of one portion to be they are formed. positioned between the teeth of the other portion THOMAS RALPH GOLDSMITH.