Oct 1, '1946-_ ‘D.T. E. FIELDING _- 2,408,618 - MA-QHINE FOR GRINDING‘ DRILLS AND SIMILAR TOOLS Filed Aprii 15," 1945 o m J, E\ \ .QWNM, $0 P ~ .. 4 3 Sheets-Sheet 1 A? ATI'ORNEYS ’ Oct. 1, 1946. ‘2,408,61 8 D. T. E. FlELDlNG MACHINE FOR GRINDING DRILLS AND SIMILA‘R TOOLS vFiled April 15, 1945 3 Sheets—Sheet- 2 *5. \S .I L v ‘0 W W»? non . m/(?fLIN VEQ-0 E R‘ ‘ ~ Oct. 1, 1946.f " ' ' D. T. \EQFIELDING‘ ‘ ~2,408,618 MACHINE FOR GRINDI'NvGv‘D-RILLS AND SIMILAR TOOLS Filed Api~i1 15, 1945 = ' J3‘SheetS-Sheet s A F1g'.9.1\\ ' . ,FiglO. - ' \ I . ’ L / mvENToR. \6 I a] ‘ ATTORNEYS ‘ Patented Oct. 1, 1946 2,408,618 ' UNITED STATES PATENT OFFICE ' David Thomas Edward Fielding,’ Middleton Junc- » _ > tion, England _ V a Application' April 13, ‘1945, Serial No. 588,158‘ v i In Great Britain May 15, 1944 a _ 1 Claim. ' (01. ale-1219i 1 2 . This invention relates to improvements in ma " 1 means for securing the tool in its supporting chines for grinding twist drills and similar tools _ In. the form of the invention illustrated in the of the kind in which the tool is passed across the carriers. face of the grinding wheel.‘ I r ' ~ - is mounted on a horizontal shaft so that its 1 A bracket mounted on a pivot carried by a second bracket so that it can be moved?to bring the I . V drawings the grinding wheel A is driven directly from the electric motor B being secured‘on the - According to the invention the grinding wheel grinding face is vertical and the tool is supported at a suitable angle to the grinding face by a \ end- of the shaft b thereof. , The motor B is-a?ixed to a slide C7 mounted in horizontal guides c on the frame D. The slide’ C and with it the motorB and grinding wheel A, is moved towards the tool A1 by a cam or eccentric c1_ actuated by a handle 0"! against the pressure of a return spring 03, the movement of the cam 01 beyond its maximum throw being prevented‘ by the stop 04. The cam tool into various positions relative to the grind ing face when grinding clearances on the cutting edge such as the cutting edge clearance and c1. acts on the head of a screw 05 in the end of additional clearance‘ behind the cutting edge clearance and for thinning the drill .point,.the 15 the slide Cand affixed therein by the set screw c". The forward position of the grinding wheel A second bracket being pivoted on a third bracket can be variedv by varying the distance which the so that it can pivot in a vertical. plane to move head of the screw 05 projects from the rear of the tool in an arc acrossv the grinding face and the slide C thus allowing the wheel A to be ad the third bracket being mounted on the frame of the machine so. that it can be moved verti-. 20 justed asits grinding face a becomes worn. The tool supporting‘ bracket _E is mounted on a cally to adjust the height of the tool supporting 1 vertical pivot .f carried by‘ a second bracket F. bracket to suit various sizes. of tools and bring so that it canbe moved in a vertical plane to vary the axis of the tool to be ground into the correct the ‘angle of the cutting edge of the tool A1 rela position in relation to the _arc._along which the tool is moved over the grinding face of the grind 25 tive to the wheel A for thepurpose of forming the ing wheel. ~ - . r g _ .> cutting edge clearance, the additional clearance behind the cutting edge clearance and for thin ning the point of ‘the tool i.»e. for making as carriers formed with a V or other shaped groove narrow as possible the part between the two cut slidably mounted on the tool supporting bracket. The invention is illustrated in and will be de 30 ting edges. Figs. 8, 9 and Y10 show these three positions of the bracket E relative to the bracket scribed with reference to the accompanying F. The bracket E is formed on its edge with drawings in which: . 1 ‘ The tool is preferably supported'by adjustable - Fig. 1 is a side elevation partly in section of a grinding machine constructed in accordance with the invention. -~ I . , ' three notches e1, e’B-ande3 adapted to be engaged by a screwed or spring loaded stop ,1‘1 carried by the bracket F. When the bracket E is in the 7 position shown in Fig. 8 with the notch e2 en-_ ‘ gaged by the stop ]‘1 the tool A1 islin the position removed. . ' for grinding‘ the cutting edge with the cutting . Fig. 3 is a section on line 3-—3 Fig. 1., edge clearance; when it is inithe position shown Fig. 4 is a section‘; on line 4—4‘ Fig. 1. ' in Fig. 9 with the notch e1 engaged by the'stop ‘Fig. 4 shows diagrammatically a modi?ed con 40 f1 it is in the position for grinding the extra struction of tool carrier particularlyv for tools of clearance behind the cutting edgeuclearance of small diameter. g , ~ ‘ the tool A1; and when it is in the position shown Fig. 6'is a section on line 6-6 Fig. 5. in Fig. 10 with the notch e3 engaged by the stop Fig. 7, 7a, 7b and 7°v areiviews-iof the ‘tool car 45 I1 it: isiin the position for thinning the point'of rier illustrated in Fig. 5 and 6 showing means for the tool A. By varying the various stop posi tions the cutting edges of the tool can be ground setting and centering the tool in the carrier. Fig. 2 is a plan ofsame with thedriving motor Fig. 8 is a section taken on the line 8—8 in Fig, l, and - Figs. 9 and 10 are sections taken on said sec to any desired angle and if necessary where a relatively large clearance to the cutting edge is 50 desired, this may be obtained by moving the tion line, illustrating the different angular posi bracket E so that the notch e1 is beyond the tions of the tool when grinding the cutting edges thereof. stop 1*‘. Figs. 11 and 12 are a plan and transverse sec tion respectively and drawn to a larger scale, of . The tool A1 is carried on the bracket E by supports E1 and E2 the bearing surface of each being in the form of a y groove. The Support 2,408,618 4 3 cam h6 and located in the horizontal position shown in Fig. 9. The face of the wheel A is then moved up to the ?rst cutting edge of the tool E1 adjacent to the wheel A is ?xed and the sup port E2 is slidably mounted on the bracket E being secured in any desired position by the clamp 64. [The tool is held against the wheel A by the cam or eccentric c1 and any ?nal ?ne ad by a screw e5 which is also slidably mounted on justment made by the screw 65 carried by the ' the bracket E and adapted to be‘ secured in1rany member E3. vThe motor B is then started and the desired position relative to the wheel A by the bracket F’ oscillated about its pivot h to cause the cutting edge of the tool to travel in an are over the face of the wheel A until suiiicient ma clamp 66. For small tools, the supports E1 and E2 may“ be replaced by an expandible chuck or holder 9 on the end of a spindle 91 carried in a housing‘. G' ‘1.0. terial has been ground off. slidabfy mounted on the bracket E as shown in Figs.5 and 6 a ‘is i - . - ' 1 .The wheel A is then moved backwards from the tool by the cam motion C, the tool reversed in the supports El and E2 and the wheel again To facilitate the correct centering of the tool‘ 7 _ brought into its operative position to grind the in the holder 9, which is difficult with verylsrnall 15 second edge so that both edges are ground for the same setting of the tool and accordingly both drills, the housing G may be removed from the edges will be alike. The extra clearances for both bracket E and placed on a centering device K_ cutting edges are next ground by moving the such as shown in Figs: '7, 7a, 7b and 7°. The de-’ bracket E to the position shown in Fig. 9, the vice K comprises twoi plates k1 and 702 having their operating faces k3 andrlr1 situated in the 20 wheel A being retracted from the tool after one clearance has been ground to allow the tool to same plane so that when the end of the tool A1 be reversed in the supports and ?nally the is placed in the device the points of the tool will bracket E is moved into the position shown in be correctly set as indicated in Figs. Tb and 7“. . Fig. 10 for thinning the point at both sides. When The bracket Fe is mounted on a horizontal pivot in this position no oscillating movement is given 25 it carried by a bracket H. The bracket F can be to the bracket F. oscillated in a vertical plane to traverse the cut As the tool A1 passes in an arc across the face ting edge a1 of the tool A1 in an are‘ over the face of the grinding wheel A it tends to keep the face of the grinding wheel A. ' true and prevents the formation of grooves The bracket H is mounted in vertical guides at therein. carried by the frame D for adjusting the-height I claim: of the tool A1 relative to the wheel A for the cor In a machine for grinding twist drills and sim rect setting of the tool according to its diameter. ilar tools of the kind referred to, the combina The height of the bracket His controlled by the tion of a grinding wheel mounted on a horizon cam 726 on the sleeve h1 which is operated by the hand wheel hr‘. The wheel h2 is preferably pro 35 tal shaft so that its grinding face is vertical and a frame carrying the said shaft, a bracket sup vided with a graduated scale It3 (see Fig. 3) work porting the tool at a'suitable angle to the grind ing over a fixed. indicator It4 so that the correct ing-face of the wheel; a second bracket on which setting of the bracket H for-any given ‘diameter the tool supporting bracket is pivotally mount~ of tool A1 ‘within the limits depending on the ' 40 ed so that the latter can be moved to bring the . . cam it can be readily obtained; As it is desirable that the tool A1 should not be moved over theiface of the-wheel A when thinning- the point of the'tooL/a stopcl1 (see Figs. 3, 8, 9 and i0) 'i's‘v-provided on the‘ frame D to pre vent movement of the bracketsE and F across the face of the wheel when the bracket E is in the position shown in Fig. 10 for thinning the point of the tool but which will allow the brack ets to move over the face of the wheel when grind ing the cutting edge clearance and the extra ' clearance behind the cutting edge clearance. When grinding a large drill‘ it may be desir able to secure the drill in thercarrier E1 and means for so doing are illustrated in Figs. '11 . and 12. The‘means illustrated comprise a peg e7 at the bottom of the V groove in the carrier E1 which engages one radial face of the. drill and/ or a clamp 68 adjustable mounted on¢a rod e9 tool into‘ various positions relative to the grind ing face when grinding clearances on the cut tingedge such as the cutting edge clearance and additional clearance behind the cutting edge clearance and for thinning the drill point, a third bracket on which the'second bracket is mounted to pivot in‘ a vertical plane to move the tool in an arc across the grinding face of the wheel and guides carried by the frame on which the third bracket is mounted so that it can be moved ver tically to adjust the height of the tool support ing bracket to suit Various sizes of tools and bring the axis of the tool to be ground into the correct position in relation to the are along which the‘ tool is moved over the grinding face of the grinding wheel, a slide or the frame on which the grinding wheel is mounted so that its grind ing face can be moved to and away from the tool, carried by an extension of ‘the carrier E1 and a spring tending to move the wheel in a back 60 adapted to' be secured against the circumferen tial face of the drill. . . In operation the tool A1 is placed on the sup ports E1 and E2 ‘and the bracket E raised to the correct height for the diameter of the tool by the l ward direction and a cam for moving itina for ward direction against the pressure of the spring. DAVID THOMAS EDWARD FIELDING.