US2024268A

US2024268A - Drill grinding machine

Info

Publication number: US2024268A
Application number: US614952A
Authority: US
Inventors: Bausch Edward; William L Flad
Original assignee: Bausch and Lomb Inc
Current assignee: Bausch and Lomb Inc
Priority date: 1932-06-02
Filing date: 1932-06-02
Publication date: 1935-12-17
Anticipated expiration: 1952-12-17

Description

1935- E; B UScHE'T' AL 2,024,268

' DRILL GRINDING MACHINE Filed June 2, 1952 3 Shets-Shet I EDWARD sAUscH WILLIAM FLAD INYENTORS ATTORNEY Dec. 17, 1935. E. BAUSCH ET AL DRILL GRINDING MACHINE 3 Shee ts -Sheet 2 Filed June 2; 1932 FIG. 2-

EDWARD BAUSCH WILLIAM L. F'LAD,

Dec. 17, 1935. i=1 BAUSCH an. 2,024,268

DRILL GRINDING MACHINE I Filed June 2, 1952 S SheetS-Sheet s EDWARD BAU SCH WILLIAM L. FLAD INVENTORS ATTORNEY Patented Dec. 17, 1935 DRILL GRINDING MACHINE Edward Bausch, Rochester, and William L. Flad, Iro'ndequoit, N. Y., assignors to Bansch & Lomb Optical Company, Rochester, N. Y., a corpora-;

tion of New York' Application June 2, 1932, Serial No. 614,952

3 Claims.

This invention relates to devices for grinding the points of twist drills and the like and more particularly it has reference to means for properly locating and holding the drill in contact with the grinding element.

One of the objects of our invention is to provide a drill grinding machine which will be convenient and simple in structure yet eiiicient in operation. Another object is to provide a drill grinding mam chine having optical means for locating andpositioning the drill. A further object is to provide an improved chucking device for holding twist drills in position to be ground. These and other objects and advantages reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully described and pointed out in the appended claims. v 1

Referring to the drawings:

Fig. l is a side elevation of a drill grinding machine embodying our invention, with parts broken away.

Fig. 2 is an enlarged top plan view of same.

Fig. 3 is an enlarged sectional view through the drill holding means and support.

Fig. 4 is an enlarged view of a detail ofthe drill holding means.

Fig. 5 is a fragmentary view showing the angularly adjustable support for the drill holding means.

Fig. 6 is a sectional view on line 66 of Fig. 5.

Fig. '7 is a view showing the bushing on a drill in separated relation to the collet.

Fig. 8 is a side view of the bushing.

A preierredembodiment of our invention is shown on the drawings wherein l0 indicates a base which carries the vertical column I having a threaded portion l2. slidably and swingably mounted on column H is the arm l3 having a clamping member I4 for holding it in adjusted position. A nut I55 cooperating with the threaded portion l2 serves as an adjustable limiting stop for the arm l3. Mounted on arm I3 is a motor M which is supplied with electric current by means of connecting cord IS. The motor M has a vertically positioned shaft H on which is mounted the diskshaped grinding element 8 having aflat. annular grinding surface IS on its upper surface. A suitable guard member 20, attached to the frame of motor M serves to enclose the grinding element l8 except on the top side.

Fixedly mounted on column II is a. bracket member 2| having an integral boss 22 provided with a curved slide portion 23. An arm 24, provided with an arcuate slot 25, is adapted to be.

adjusted along the slide portion 23'and held in adjusted position by means of screw 26 which passes through the slot. Threadedly mounted on the end of arm 24 is a screw 21 having oppositely disposed bearing recesses 23 and 23' in which are mounted the pivot members 29 and v 30 for supporting the tubular bearing member 3|. Slidably and rotatably mounted within bearing member 3| is the sleeve 32 having an enlargedend portion 33 provided with a tapered inner wall 34. 1O Rotatably mounted within the sleeve 32 is the tube 35 having an integralhead portion 36 and av threaded portion 31 which cooperates with' the threaded portion on collet chuck 38. A bushing 39, which is split asat 40, is slipped over the end of the'drill D to be ground, as shown in Fig. 7. The bushing fits snugly overthe' end of the drill and a separate, individual bushing ispreferably supplied for each drill'size. The bushing and drill are positioned within the

collet chuck

38 and 20 the threaded tube 35 is turned so as to draw the tapered wall of the collet into engagement with the tapered wall 34 of the'sleeve 32'thereby clamping the bushing and drill firmly in position, as shown in Fig. 3. r Secured to sleeve 32, adjacent its top,'is a collar 4| having a clamping screw '42 for releasably clamping the collar so as to engage sleeve 32. The collar 4| has two'projecting lugs 43 which are 180 degrees apart and adapted to enter two cor- 30 respondingly spaced notches 44 formed on bearing member 3|. The sleeve 32 and its'associated parts may thus be slid axially in bearing member 3| against the action of coil spring 45 and rotated 180 degrees for a purpose to be hereinafter described. A rod 46 is slidably mounted within tube 35 and is used for ejecting and posie tioning the drill.

Pivotallymounted on bracket 2| is a rod 41 adapted to swing upward about a horizontal axis, 40 the downward movement/of said rod 41 being limited by the adjustable stop screw 43 carried by bracket 2|. Adjustably mounted on the free end of rod "is the tube 49 within which the microscope 50 is slidably mounted to provide for 5 focusing adjustments. The microscope i0 is provided with a suitable cross hair or flduclal line, not shown, to enable the operator to properly position a twist drill in the chuck.

In grinding a twist drill properly it is neces- 0 sary to have the sharp edge or dead center in the axial plane of the drill. The web of the drill should be symmetrically positioned with respect to the axial plane and the two cutting lips should make equal angles with the drill axis.

Corresponding points on the two cutting edges are therefore 180 degrees apart.

In operation of our device, the drill D is clamped in the chuck and positioned in alignment with the microscope 50 as shown in Fig. 2. The operator then loosens clamping screw 42 on collar ll thereby permitting the sleeve and drill D to be rotated with respect to member 3| until one of the cutting lips is aligned with a cross hair when viewed through the microscope 5 0. The sleeve and drill are then moved up against'the action of spring 45 and rotated until the lug 44 cooperates with the notch on the opposite side member 31. The other cutting lip is then viewed through the microscope and if it coincides with the cross hair, the drill is properly located in the chuck. If not, the screw 42' is again loosened and the sleeve turned with respect to the collar 4| and adjustments made so that upon rotating the drill and sleeve 180 degrees corresponding points on the two cutting lips will coincide with the cross hair. When this condition is reached the drill is properly located in the chuck.

- The chuck is held in the hand and rocked back and forth to the right of the vertical plane pass ing through the

pivots

29 and 30 as the drill contacts with the grinding surface. This provides for a suitable clearance for the cutting lips. For

most purposes an angle of 59 degrees between the cutting lip and the axis provides an efllciently operating drill. For certain purposes, however, it is desirable to utilize a difierent angle and so means is provided for adjusting this angle by loosening screw 26 and angularly adjusting the bracket arm 24, the angle being indicated on a scale 5| carried by boss 22. After one lip has been ground, the sleeve is pulled out to disengage li'ig 43 and turned 180 degrees to permit the lug to engage the notch 44 on-the opposite side. This action turns the drill 180 degrees and solocates the drill in proper position to grind the other lip.

It the drill has been broken oil so there is considerable grinding to be done, the drill may be raised up from the wheel I! by means 0! screw 21 so that small increments can be fed gradually down toward the stone. In the finishing position, however, the screw 21,must be positioned with its head engaging the top of bracket 24 as shown in Fig. 3,

To prevent undue wearing in one path on the wheel, the motor and wheel may be laterally ad- Justed by loosening screw l4 and swinging the arm I3 together with the motor and grinding wheel. A bracket 52, projecting outwardly from member 2|, carries a rotatably mounted block 53 in which a diamond 54 is eccentrically mounted so that the diamond can be moved over the grinding surface I! for the purpose of truingit.

From the foregoing it will be apparent that we have provided an improved means for accurately and conveniently grinding twist drills. Our device is especially adapted for sharpening twist drills of relatively small sizes. The drills can 5 be inspected and sharpened without removing them from the chuck. The indexing lugs on collar 42 provide an accurate and convenient means for locating the drill in the chuck' so that both cutting lips can be ground quickly. The optical device provides an especially accurate means for locating the drills in the chuck and its advantage in connection with the smaller drills is readily apparent. The use of the bushing 39 at the end of the drill affords a firm holding .device which keeps the drill from being bent or ,a sleeve slidably and rotatably mounted within said member, a collet and cooperating threaded tube for holding a drill within said sleeve, a collar adjustably mounted on said sleeve, means for clamping said collar in adjusted position, and cooperating indexing means on said collar and member for locating the drill with respect to said member.

2. A drill grinding machine comprising a vertical support, an arm mounted to turn about said support in a horizontal plane, a grinding element mounted on said arm to rotate about a 40 vertical axis, a bracket carried by said support, an arm pivotally carried by said bracket, drill holding means for holding a drill in contact with said element, said holding means being longitudinally movable and pivotally mounted on said arm to turn about an inclined axis, a rod movably mounted on said bracket and a microscope mounted on'said rod, said microscope having fiducial means for locating the drill relativeto said element. l

3. A drill grinding machine having in combination drill holding means comprising a bearing member adjustably mounted to turn about an inclined axis; means for adjusting said bearing member along said axis, a sleeve slidably and rotatably mounted within said member, a collet and cooperating threaded tube for holding a drill within said sleeve, a collar adjustably mounted on said sleeve, means for clamping said collar in adjusted position, and cooperating index means on saidv collar and member for locating the drill with respect to said member.

. EDWARD BAUSCH.

WILLIAM L. FLAD.