US3100956A

US3100956A - Drill grinding apparatus

Info

Publication number: US3100956A
Application number: US252750A
Authority: US
Inventors: Niquet Samuel
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-01-21
Filing date: 1963-01-21
Publication date: 1963-08-20
Anticipated expiration: 1980-08-20

Description

S. NIQUET DRILL GRINDING APPARATUS Aug. 20, 1963 Filed Jan. 21, 1963 y wvszvran Samuel N/OUE T tates 3,10d,956 DRILL GRINDING APPARATUS Samuel Niquet, 172 Bates St, New Bedford, Mass.

Filed Jan. 21, 1963, Ser. No. 252,750 6 Claims. (Cl. 511-219 The present invention relates to a drill grinding apparatus and more particularly to such an apparatus capable .of grinding the cutting lips at the point of the drill.

The general object of the present invention resides in the provision of an apparatus of the character described which is capable of grinding several drills simultaneously.

Another important object of the present invention reatet sides in the provision of an apparatus of the character the provision of a machine or apparatus of the character 7 described in which drills with left hand or right hand twisted flutes may be ground.

The foregoing and other objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:

FIGURE 1 is perspective view of the apparatus in accordance with the invention; j

FIGURE 2 is a top plan view of part of the same;

FIGURE 3 is a partial elevation of a drill; and

FIGURE 4 is an end elevation of the point thereof.

Referring now more particularly to the drawings in which like references, characters indicate like elements throughout the apparatus in accordance with the invention is adapted to grind or sharpen the point of conventional twist drills provided with spirally arranged flutes 2 each defining a cutting edge 3 having a land or narrow strip 4 immediately trailing the same. i

The drill point has a generally conical point, the cutting lips 5 being at an angle a with the drill axis, this cutting angle of the drill being usually about 59 and the heel surface 6 trailing each cutting lip 5 sloping away from the cutting lips 5 at a lip clearance angle of approximately 12 to 15.

The intersection of the heel surfaces 6 results in the formation of a central chisel point or dead center 7 which extends across between the cutting lips 5.

The apparatus comprises a U-shaped support rod 8 the transverse leg 9 of which is freely pivoted within two spaced journal members 10 which are secured to a base plate 1.1. The free legs 12. of rod 8 extend at right angles to transverse leg 9 and are parallel to each other and disposed in the same plane and their free ends are provided with rest blocks 13 preferably of cylindrical shape. The blocks 13 are secured to legs 12 at the same level.

An arm 14 is secured to the central portion of transverse leg 9 and is provided at its rear outer end with an adjustment screw 15 which abuts against base plate 11.

Bracing strips 16 are secured to the rear end of arm 14 at 17 and their other ends are each provided with a hole through which passes a free leg 12 of support rod 8, said other ends being located just underneath the associated rest block 13. i

The resulting supporting assembly is disposed in a ice 2 suitable relationship with a bevelled grinding wheel 13 which is driven by a suitable electric motor 19'. The bevelled surface 20 of grinding wheel 18 is oriented in such a way, with its drive shaft 21 being horizontal that the vertical plane tangent to said bevelled surface 20 will be parallel to the line joining the corners defined by the top surfaces of the rest blocks 13 with the forward surfaces of the portion of the free legs 12 protruding upwardly from rest blocks 13. These corners act as abut ment and journal surfaces for the legs 22' of L-shaped pivot rods 23, the other legs 24 of which are secured to and rigidly interconnected at their free ends by a transverse bar 25. Legs 24 are parallel to each other and in the same plane while pivot legs 22 are co-ax-ial and spaced from each other. The legs 24 are slidable through bores made at the ends of a second bar 26 and their position may be adjustably locked within bar 26 by means of set screw 27. The center of second bar 26 is provided with a notch 28, the bottom of which is at an angle with respect to the right angular faces of bar 26 which has a rectangular cross section. Notch 28 receives the underface portion andside face portions of a slotted main bar 29 which is rigidly secured to second bar 26 by means of a bolt 31? passing through the slot 31 of main bar 29 and screwed within a threaded bore of second bar 26.

An abutment and guiding plate 32 is secured to the upper end of slotted main bar 29, said plate is disposed in a plane at right angles to the long axis of main bar 23 and across the end thereof, being provided with a right angular flange 33 extending underneath and secured to the upper end portion of bar 29. The top abutment edge 34 of plate 32 is recessed with respect to end lugs 35.

A rectangular suppont plate 36 is positioned over main bar 29 and extends across the same. Plate 36 is secured to an underlying guiding block 37 which slidably fits within slot 31 of bar 29 such that the entire plate 36 can be slid along bar 29' while remaining parallel to itself. Guiding block 37 protrudes from the lower edge of plate 36 and a clamping strap 38 is secured thereto by means of a rivet or the like.

Clamping strap 38 overlies the top face and side faces of the main bar 29 and is provided with a set screw 40 which engages the corresponding side face of the main bar 29 to firmly lock the rectangular plate 36 in adjusted position longitudinally of the main bar 29.

A channel member 41 is secured by rivets 42 or the like to the top face of plate 36 and is disposed longi tudinally thereof- A block 43 is arranged for, guided movement over plate 36 in accordance with the double arrow 44. Block 43 has a notch 45 made at the underface thereof in which fits the protruding portion of the channel member 41. A set screw 46 is threaded through block 43 with the free end of the shank of said screw protruding through notch 45 to engage underneath lip 47 of channel member 41; when the set screw 46 is loose, the block 43 may be slide along lip 47 while being retained thereto by the protruding end, of the set screw; when the latter is screwed tight against the web of the channel member 41, the block 43 is locked in adjusted position on plate 36. p

A strip 48 rests on the top face. of the Web of the channel member 41 and passes through the notch 45 of block 43 and is provided at one end with an upstanding flange 49. When set screw 46 is tightened, strip 48 is locked in position with respect to block 43 and also with respect to main plate 36; when set screw 46 is loose, strip 48 may be adjusted transversally with respect to the plate 36 as well as block 43 so as to adjust the distance between flange 49 and one or the other of the bevelled end faces 50 of block 43. The position of strip 48 may be reversed from that shown in FIGURE 1 with the a 22 of the pivot rods 23, angular position of the cutting-lip with respect to the long axis of each drill is automatically obtained due flange 49 disposedon the right hand side instead of the left hand side of block 43.

The apparatus in accordance with the invention is used as follows:

A plurality ofdrills 1 to be sharpened are disposed on the abutment and guiding plate 32 between its end lugs 35 and on the rectangularplate 36 with their shank end abutting against channel member 41 with the outer drills of the setabutting against flange 49 of strip 48 and one or the other of bevelled end faces 50' of block 43. In this position, the drills lie in a plane substantially. parallel to main bar 29' and above the latter. One

or more drills up to 12. or:15 may be positioned inthismanner. The longitudinal position of strip- 48 is adjusted to maintain the drills inside by side contiguous relationship after the transverse position of block 43 had been adjusted laterally of plate 36 in order to adjust the inclination of the several drills in accordance with the cutting angle oz of the tips of said drills. If desired, the lip 47 of channel member 41 may be graduated in degrees to facilitate lateral adjustment of block 43 in accordance with the cutting angle of the drills.

The drills may be-inclined towards the right or left with respect to the main bar 29 in accordance whether they have lefthand-or right hand twist flutes, by positioning said drills on one side or the other of block 43 and. by reversing the position of strip 48 accordingly. The longitudinal position. of the rectangular platev 36 with respect to main bar 29 is also adjusted in accord- 1 ance with the length of the particular set of drills being sharpened or to be sharpened. The plate 36 is adjusted such that the tip end of the drills will protrude approximately Ms of an inch from the transverse alined .legs in this manner, the correct to the fact that the outtingedges 3 of the two diametrically opposed flutes 2 rest on the edge 34 of guiding plate 32. i

The bevel of the notch 28 made in bar 26 is such that the L-shaped rods 23 are disposed in a plane makes approximately-a 22 angle with the plane ofslotted bar 29.

Y Bar 26 is longitudinally adjusted in a permanent manher by means of bolt 30 along main bar 29 in such position that the axes of legs 22 of rods 23 will be connected by a line passing through the abutment edge 34 of plate 32] The degreeof clearance desired for the heel surfaces 6, that is the lip clearance angle, is obtained by adjusting 24 in accordance with the lip clearance angle. obtainable.

and also for various diameters of drills.

Once the drill holding apparatus has been adjusted as above described, the position of the rest blocks 13 and therefore of the pivot legs 22 of rods 23 towards or away from the surface 20 of the grinding wheel is adjusted by screwing or unscrewing the adjustment screw 15 to thereby pivot leg'9 Within journal members with this adjustment the tips of the drills 1 are brought into grinding contact with the abrading surface 20 of the grinding wheel 18.

Once the apparatus has been adjusted, the drills are pressed in position against the edge 34 of plate 32 and against rectangular plate 36 with one hand while the other hand grasps the outer end of main bar 29 and moves the entire assembly in .a swinging vertical movement about the p ivotsconstituted by legs 22 of rods 23. The entire arouses assembly is also simultaneously transversally displaced by sliding legs 22 on the rest blocks 13 so as to vary the lateral zone of engagement of the drill tips with the grinding surface of wheel 18.

Once one lip 5 of the drills has been sharpened together with the associated heel surface 6 the drills of the entire set are turned through half a turn so as to be able to sharpen the other lip and associated heel surface.

From the foregoing, it is apparent that several drills may be sharpened simultaneously and that the apparatus is highly flexible because it can sharpen drills of different diameters and lengths and also with different cutting angles and lip clearance angles.

It will also be noted that the grinding streaks or ridges formed onthe heel surface 6 extend back away from the cutting lip 5 rather than transversely thereacross. Thus, the heel surface has a minimum binding friction with a Work piece and the drill operates more smoothly.

Drills sharpened with the. apparatus of the invention. have been found to last much longer before a subsequent resharpening is required.

While a preferred embodiment in accordance with the invention has been illustrated and described, it is understood that various modifications may be resorted to without'departing from the spirit and scope of the appended claims.

What I claim is:

1. Multiple drill grinding apparatus comprising rotatable abrasive inea-ns having agrinding surface presenting a substantially flat transverse operative portion, and drill holding means associated with said abrasive means, said holding means comprising spaced support and pivot means disposed at the level of said operative portion of said grinding surface and on each side thereof, the line connecting said spaced support and pivot means being substantially parallel to said operative portion, a U-shaped support frame including a transverse member, spaced parallel legs and spaced axially aligned pivot members depending from said legs at an angle thereto, said pivot members engaging said support and pivot means for swinging movement with respect to said support and pivot means, a bar carried by said frame and disposed between said legs and longitudinal ly thereof, multiple drill support means carried by said bar to hold a plurality of drills side by side and in contiguous relationship with the longitudinal axes of said drills inclined to said operative portion of said grinding surface at an angle equal to the cuttug angle of the drill tips and with the tips of said drills in the vicinity of a l ne joining the axes of'saicl pivot members and offset from said line, whereby, with a cutting lip and associated heel surface of said several drills held in contact with said operative portion of said grinding surface, swinging movement of said frame about said support and pivot means will produce sharpening of said cutting lip and grinding of said heel surface of each of said several drills.

2 Multiple drill grinding apparatus as claimed in claim 1 wherein said pivot members are also supported on said support and pivot means for transverse displacement of said frame with respect to, said support and pivot means so as to laterally displace the portion of said drill tips in engagement with said operative portion of said grinding surface laterally of the latter.

3. Multiple grinding apparatus as claimed in claim 1, wherein said drill support means support said drills in a plane substantially parallel to that of said frame and said frame is mounted at an angle to the plane of said legs,

and further including means to vary the position of said pivot members With respect. to the adjacent end of said frame longitudinally of said drill tips from the line joining the axes of said pivot members.

4. Multiple drill grinding apparatus as claimed in claim 1, wherein said multiple drill support means include a support member secured to the end of said frame adjacent said pivot members and defining a drill engaging support edge, lugs upstanding from said edge at both ends thereof,

and a support plate mounted on said frame in an area spaced from said support edge and having means forengaging the shank ends of said drills, said support plwe adjustable longitudinally on said frame to thereby adjust the length of the tip portion of said drills protruding from said support edge, said last named means adjustably movable transversely of said frame to thereby vary the inclination of said drills with respect to the long axis of said frame.

5. Multiple drill grinding apparatus as claimed in claim 4, wherein said frame is mounted at an angle with respect to the plane passing through said legs, and said drill support edge is disposed on a line intercepting the long axes of said legs, and means to vary the position of said pivot members with respect to said support edge longitudinally of said frame to thereby vary the degree of offset of the drill tips With respect to a line joining the axes of said pivot members.

6. A multiple drill grinding apparatus as claimed in claim 1, further including means to adjust the position of said support and pivot means towards and away from said operative portion of said grinding surface.

References Cited in the file of this patent UNITED STATES PATENTS 3,089,290 Wurm-Reithmayer May 14, 1963

Claims

1. MULTIPLE DRILL GRINDING APPARATUS COMPRISING ROTATABLE ABRASIVE MEANS HAVING A GRINDING SURFACE PRESENTING A SUBSTANTIALLY FLAT TRANSVERSE OPERATIVE PORTION, AND DRILL HOLDING MEANS ASSOCIATED WITH SAID ABRASIVE MEANS, SAID HOLDING MEANS COMPRISING SPACED SUPPORT AND PIVOT MEANS DISPOSED AT THE LEVEL OF SAID OPERATIVE PORTION OF SAID GRINDING SURFACE AND ON EACH SIDE THEREOF, THE LINE CONNECTING SAID SPACED SUPPORT AND PIVOT MEANS BEING SUBSTANTIALLY PARALLEL TO SAID OPERATIVE PORTION, A U-SHAPED SUPPORT FRAME INCLUDING A TRANSVERSE MEMBER, SPACED PARALLEL LEGS AND SPACED AXIALLY ALIGNED PIVOT MEMBERS DEPENDING FROM SAID LEGS AT AN ANGLE THERETO, SAID PIVOT MEMBERS ENGAGING SAID SUPPORT AND PIVOT MEANS FOR SWINGING MOVEMENT WITH RESPECT TO SAID SUPPORT AND PIVOT MEANS, A BAR CARRIED BY SAID FRAME AND DISPOSED BETWEEN SAID LEGS AND LONGITUDINALLY THEREOF, MULTIPLE DRILL SUPPORT MEANS CARRIED BY SAID BAR TO HOLD A PLURALITY OF DRILLS SIDE BY SIDE AND IN CONTIGUOUS RELATIONSHIP WITH THE LONGITUDINAL AXES OF SAID DRILLS INCLINED TO SAID OPERATIVE PORTION OF SAID GRINDING SURFACE AT AN ANGLE EQUAL TO THE CUTTING ANGLE OF THE DRILL TIPS AND WITH THE TIPS OF SAID DRILLS IN THE VICINITY OF A LINE JOINING THE AXES OF SAID PIVOT MEMBERS AND OFFSET FROM SAID LINE, WHEREBY, WITH A CUTTING LIP AND ASSOCIATED HEEL SURFACE OF SAID SEVERAL DRILLS HELD IN CONTACT WITH SAID OPERATIVE PORTION OF SAID GRINDING SURFACE, SWINGING MOVEMENT OF SAID FRAME ABOUT SAID SUPPORT AND PIVOT MEANS WILL PRODUCE SHARPENING OF SAID CUTTING LIP AND GRINDING OF SAID HEEL SURFACE OF EACH OF SAID SEVERAL DRILLS.