US2139938A - Machine for grinding drill bits - Google Patents

Description

. 13, 1938. F, DlXON v 2,139,938

MACHINE FOR GRINDING DRILL BITS Filed Dec. 4, 1937 5 Sheetsheet 1 311/1) Wwto't/ v r 76 Fax fie Dixon Dec. 13, 19%. F N 2,139,938 I MACHINE FOR GRINDING DRILL BITS Fil ed Dec. 4, 1937 s Sheetsheet 2 T gmwm 7.11.1?

" v Fife Dixon Dec. 13, 1938. F. DIXON MACHINE FOR GRINDING DRIL L BITS 5 Sheets-Sheet 5 Filed Dec. 4, 1957 Fate Dixon Patented Dec. 13, 1938 their MACHINE FOR GRINDING DRILL BITS Fate Dixon, Durham, N. 0., assignor of one-half to Samuel A. Poole, Durham, N. 0.

Application December 4, 1937, Serial No. 178,167

Claims.

My invention relates to a machine for sharpening or grinding the ends of drill bits or the like.

An important object of the invention is to provide a machine of the above mentioned character,

5 having proper adjustments for grinding the angularly disposed faces upon the drill bit.

A further object of the invention is to provide a machine of the above mentioned character, the grinding action of which is manually controlled.

A further object of the invention is to provide a machine of the above mentioned character so constructed that the drill bit is manually rocked upon the grinding surface from the leading point to the trailing point.

A further object of the invention is to provide means for bodily raising and lowering the drill bit during the grinding action to properly distribute the wear upon the rotary grinding element or stone.

A further object of the invention is toprovide a stop to engage with the drill bit when properly set in the chuck or holding jaws for grinding one face, and adapted to engage with the bit to properly locate the same in the chuck so that the 25 other face will be ground at the same angle.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part 30 of this application and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a perspective view of a machine embodying my invention,

Figure 2 is a plan View of the same,

Figure 2a is an enlarged detailed view of the carriage movement indicating means,

Figure 3 is a side elevation of the same, showing the clamp holding the bit generally parallel 40 to the grinder and spaced therefrom,

Figure 3a is a detailed section taken on line 3a3a of Figure 3,

Figure 3b is a detailed section taken on line 3b-3b of Figure 3,

Figure 4 is a side elevation of the machine, parts in section, with the bit clamp swung to a position to hold the bit in an angular position for contact with the rotary grinder,

Figure 4a is a. detailed section taken on line 50 4a--4a of Figure 3,

Figure 5 is a plan view of the machine, showing the parts in the adjusted position as shown in Figure 3,

Figure 6 is a side elevation, parts in section,

with the bit clamp moved upwardly and inwardly with respect to the grinder,

Figure 7 is a side elevation of the bit clamp showing the gage rod,

Figure 7a is an enlarged end elevation of the bit, associated elements being shown in elevation and broken away,

Figure 8 is a transverse section taken on line 88 of Figure 7,

Figure 9 is a plan View of the grinder, with the bit contacting therewith and shown in section, and,

Figure 10 is a similar view, at right angles to ings I'l, rotatably receiving a horizontal shaft l8, driven by a pulley l9, engaged by a belt 25, in turn driven by the rotary element of any suitable prime mover.

horizontal shaft Rigidly mounted upon the IB is a rotary grinding element or stone 2|, clamped to the shaft l8 for rotation therewith, by any suitable means, and preferably in a manner whereby the grinding element may be longitudinally adjusted upon the shaft it.

A vertically swinging frame 22 is mounted upon the vertical arms I6, comprising side bars 23, the forward ends of which have openings 24 to pivotally receive a horizontal shaft 25, secured to the arms IS. The arms 23 are rigidly connected by horizontal rods 26, and these rods 26 are parallel with the rotary shaft 18.

Slidably mounted upon the guide shafts 26 of the frame 22 is 28, to receive the a carriage 21, having openings rods 26. This carriage is adapted to have rectilinear reciprocatory movement and is provided between the openings 28 with a screw-threaded opening 29, for receiving the screw-threaded portion 30 of a rotary operating shaft 3 I.

One reduced end 32 of the shaft 3! is rotatable within the opening 33; while the opposite end portion of the shaft is rotatable within an opening 34, and the shaft 3| has collars 35,

clamped thereon,

jacent side 23.

upon opposite faces of the ad- It is thus seen that the screw threaded shaft 3i can turn with respect to the sides 23 but cannot move longitudinally with relation thereto.

The shaft 3! is turned by a knurled head 35 or the like. It is thus seen that by turning the shaft 3|, the carriage may be moved in a direction longitudinally of the shaft IS. The extent of movement of the carriage may be indicated by a scale 36 formed upon the sleeve 35, with a pointer 3'! formed upon the adjacent arm 23. The scale 36 is preferably calibrated in one-thirty-second of an inch, starting from zero and extending in opposite directions. The scale 33 will indicate when the carriage 21 has been shifted longitudinally with respect to the grinding element 2| for one-thirty-second of an inch or any multiple thereof. Any other suitable form of calibration may be used, if desired.

The carriage 21 is provided near its rear end with a vertical cylindrical opening 38, to rotatably receive a sleeve 39, projecting above the carriage and having a disc 49' preferably formed integral therewith, This disc is providedwith a pointer 4! to coact with a scale 42, formed upon the rear end of the carriage 21, as shown. This scale is graduated in degrees for denoting the angular disposition of the edge of the cutting end of the bit, with respect to the end face of the rotary grinder. The end face of the bit is ordinarily beveled at about 45 with respect to its longitudinal axis and when this bevel is desired, pointer 4! registers with the degree designated 45 in the scale 42. To decrease the angle of bevel on the bit, the disc 40 would be turned counterclockwise, while to increase the same the disc 46 would be turned clockwise. Means are provided to lock the sleeve 39 to the carriage 2'!- in the selected adjusted position, comprising a set screw 43, having a knurled head 44 or the like. Rotatably mounted within the adjustable sleeve 33 is a vertical post 45, carrying a stop element 43, operating within a segmental slot 41, formed in the sleeve 39, to engage an end wall 48, to limit the turning movement of the vertical post 45 in a counterclockwise direction, Figure l, to bri'ngth'e bevel face of the bit into contact with the end face of the rotary grinder. When the stop element 45 engages the end wall 48, the selected angle for the edge 49 of the face of the bit is determined. This angle is ordinarily 45 with respect to the longitudinal axis of the bit although it may be increased or decreased.

Rigidly secured to the upper end of the post 45 is a head 50, having a horizontal opening M, to pivotally receive a generally horizontal shaft 52, having a handle 53 rigid-1y secured thereto. Mounted upon the shaft 52 is a collar 54, adapted to be clamped to the shaft by a set screw'5 5 or the like. This collar carries a stop finger 56, operating above the head 59 and to contact with the top of the head when the shaft 52 is turned clockwise, Figure 5, to the limit of its clockwise movement. When the stop finger 56 engages the head 53, the bit preferably has its longitudinal axis disposed at about 45 from the vertical. This prevents any possibility of the rotary grinder swinging the bit downwardly during the grinding! action. The angular position occupied by the bit with respect to its longitudinal axis may be varied by turning the collar 54 upon the shaft 52 and again clamping the same to the shaft.

The work or bit holding device or chuck comprises a stationary jaw 51, rigidly secured to the shaft 52 and this stationary jaw coacts with an opposed movable jaw 58, rigidly secured to a pair of rods 59, slidable within openings 63'- formed in the jaw 51. The rods 59 are rigidly secured to a cross head 6!, having a screw-threaded opening 32, for receiving a screw-threaded rod 63, turned by a milled head 64. The inner end of this screwthreaded rod is arranged to contact with the stationary head 60 and thereby draw the movable jaw 58 toward the stationary jaw. The stationary jaw is provided with a V-shaped notch to receive the side of the bit 96, to cause the same to be centered, as shown. It is thus seen that the jaws 51 and 58 will clamp the bit 63 between them and properly hold the bit during the grinding action. Rigidly attached to the stationary jaw 51 is a guide rod 6?, which is preferably square in cross-section and slidably receives thereon a carriage 68, which is clamped in adjustment at a selected longitudinal position upon the rod 61 by a set screw 69 or the like. The carriage 38 has outwardly diverging jaws l8, affording a V-shaped recess H, receiving the rear end of the bit 66. The guide rod 6? has a handle 12, as shown.

The stationary jaw 51 is provided upon its forward face with a housing 13, rigidly secured thereto, having a V-shaped groove 74, to receive a gage rod 75. The gage rod is clamped in position by a set screw 16, turned by a handle Ti. The gage rod is set to engage with the face( 78 of the bit when the major portion of its edge i9 is vertical, when looking down upon the bit when in a generally horizontal position. After one face or bevel at the end of the bit has been ground, the bit is turned around in the work clamp, by proper manipulation of the parts thereof and the gage rod 75 will then engage the face 39', so that the edge 8! of the bit will be vertically arranged, This renders it possible to quickly adjust the bit within the holder or clamp and render it certain that the two bevel faces will be ground at precisely the same angle.

The operation of the machine is as follows:

The sleeve 39 may be adjusted to define the angle of bevel 49, Figure 9, and if this is to be 45 with respect to the longitudinal axis of the bit, the pointer 4| registers with 45 in the scale 42, and the sleeve 39 is clamped to the carriage in this selected adjusted position. The movable jaw 58 is now moved from the stationary jaw 5'! so that the bit 66 may be inserted between the jaws, and the rear end of the bit will engage within the V-shaped notch H. The rod 52 and the rod 5'! are now raised, the stop finger 56 engaging the top of the head 5!, and the vertical post 45 is turned until stop pin 43 engages the end wall 48. In this adjusted position, the bevel end 49 of the bit should substantially contact the end face of the rotary grinder, but if it does not, the carriage 38 is moved forwardly from the rod 61, until this occurs, after which the carriage 68 is clamped to the rod and the inner jaw 58 is moved toward the stationary jaw 51 to securely clamp the bit 63 between these jaws. Before the final clamping adjustment of the movable jaw 58, care is taken that the edge 79 of the bit is vertically disposed, which will position the bevel face 83 of the bit, next to the rotary grinder, in the proper position to contact with the end face of the grinder and be ground thereby. The gage rod 15 is sent to contact with the face l8, and is clamped in this positionQso that it may readily engage the face 88, so that the edge 8| of the bit will be vertical when the bit is reversed, for grinding the bevel face 82. With the parts thus adjusted, and the rotary grinder rotating toward the operator, the operator engages the handles 53 and i2 thereby raising the frame 22 and the elements carried thereby. The bevel face 83 of the bit is thereby brought into contact with the end face of the grinder, and at the instant of contact the handle 12 is swung downwardly, while the handle 53 is moved upwardly and inwardly. Particular attention is called to the fact that the bit is held to one side of the shaft 53 and is therefore eccentric with respect to the shaft and the downwardly swinging movement of the handle 72 causes the face 83 to be ground into a slightly convex surface, Figure 10. The leading end of edge 69 is thus shifted from the end face of the grinder while the trailing end of this face is moved in contact with the grinding face. The inward movement of the bit with respect to the rotary grinding element distributes the Wear upon the grinding element. When it is desired to increase the extent of grinding action, the bit is shifted bodily longitudinally toward the grinding wheel by advancing the carriage 21, by turning the operating shaft 3|. It is thus seen that the bit holder is capable of swinging in a horizontal plane toward the rotary grinder and also in a vertical plane, and the work holder may be also bodily raised and lowered with respect to the rotary grinder by' raising and lowering the swinging frame carrying the vertical post and the work holder may also partake of rectilinear reciprocatory movement by sliding the carriage supporting the post longitudinally of its rods.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, what I claim is:

1. In a machine for grinding the beveled end of a bit or the like, a substantially vertical rotary grinder, a relatively stationary support, a vertically swinging generally horizontal support arranged upon one side of and spaced from the rotary grinder and pivotally connected with the relatively stationary support to turn upon an axis extending longitudinally of the axis of rotation of the grinder, a carriage mounted upon the vertically swinging support, means to bodily move the carriage in a straight line with relation to the vertically swinging support in a direction longitudinally of the axis of rotation of the grinder, a generally vertical supporting device mounted upon the carriage and providing a turning axis arranged at generally a right angle to the plane of the carriage, a member mounted upon the generally vertical supporting device and permanently free to turn about the turning axis of the same within limits, a clamp disposed opposite the end of the rotary grinder and having means for holding a bit so that the longitudinal axis of the bit is arranged generally at a right angle to the end of the rotary grinder to present the end of a bit to the end of the grinder, and means to pivotally mount the clamping device upon the member so that the clamp is permalently free to be swung in a generally vertical plane while the edge of the bit engages the end of the grinder.

2. In a machine for grinding the beveled end of a bit or the like, a substantially vertical rotary grinder, arelatively stationary generally horizontal support, a vertically swinging support arranged upon one side of the grinder and pivotally connected with the relatively stationary support to turn upon an axis extending longitudinally of: the axis of rotation of the grinder, a carriage mounted upon the vertically swinging support, means to bodily move the carriage in a straight, line with relation to the vertically swinging support in a direction longitudinally of the axis of rotation of the grinder, a sleeve pivotally mounted upon the carriage and having its turning axis arranged generally vertically at generally a right angle to the plane of the carriage, means to clamp the sleeve in the selected adjusted position against turning movement, a generally vertical post having limited turning movement in the sleeve, a clamp projecting to a position generally opposite the end of the rotary grinder and presenting the bit held therein to such end, a head carried by the post and having an opening arranged at substantially a right angle to the longitudinal axis of the post, and a shaft pivotally mounted within such opening and carrying the clamp so that the clamp may be swung in a generally vertical direction and a handle secured to the shaft to turn the same upon its longitudinal. axis.

3. In a machine for' grinding the beveled end of a bit or the like, a substantially vertical rotary grinder, a generally horizontal frame arranged beneath the grinder in spaced relation thereto, means to pivotally support the frame so that it may be swung vertically toward and from the periphery of the grinder, a carriage slidably mounted upon the generally horizontal frame to move in a straight line which is substantially parallel with the axis of rotation of the grinder, an operating shaft secured to the frame and having screw threaded engagement with the carriage to move the same in the said straight line, a generally vertical sleeve mounted to turn upon the carriage, the sleeve and carriage having means to indicate the extent of turning movement, means to clamp the sleeve to the carriage against turning movement, a generally vertical post permanently freely pivotally mounted within the sleeve for turning movements within limits, a block rigidly secured to the generally vertical post and having a generally horizontal opening, a generally horizontal shaft permanently freely pivotally mounted within the opening and having its forward end extending opposite the end of the grinder, a stop having a turning adjustment upon the shaft and a part to engage the block to limit the turning movement of the shaft, a handle secured to the shaft to turn the same upon its longitudinal axis, a clamp mounted upon that end of the shaft opposite the end of the grinder and having means to hold the bit so that the longitudinal axis of the bit will be arranged generally at a right angle to the shaft and the end of the grinder, and a handle secured to the clamp and projecting laterally outwardly from the same and disposed at generally a right angle to the first named handle.

4. In a machine for grinding the beveled end of a bit or the like, a substantially vertical rotary grinder, a relatively stationary support, a generally horizontal support arranged beneath and spaced from the rotary grinder, means to pivotally mount the generally horizontal support upon the stationary support so that it may be swung vertically toward and from the grinder, a guide device mounted upon the generally hori zontal support and extending longitudinally thereof and projecting beyond one end of the rotary grinder, a carriage mounted upon the guide device, an adjusting screw to move the .carr-iage longitudinally of the guide device, a generally vertical post mounted upon the carriage and having a turning axis, the post projecting upwardly beyond the carriage, a generally horizontal shaft arranged above the carriage and mounted upon the upper end of the post and turning about the axis of the post and adapted to turn upon its longitudinal axis,,a clamp disposed opposite the end of the rotary grinder and mounted upon the generally horizontal shaft and having means to receive and hold the bit so that the longitudinal axis of the bit Will be arranged generally at a right angle to the surface of the end of the rotary grinder, and means for raising the generally horizontal support and for turning the generally horizontal shaft to present the end of the bit to the end of the grinder at varying distances from the periphery of the grinder.

5. In a machine for grinding the beveled end of a bit or the like, a substantially vertical rotary grinder, a relatively stationary support, a generally horizontal support arranged beneath and spaced from the rotary grinder, means to pivotally mount the generally horizontal support upon the stationary support so that the generally horizontal support may be swung vertically toward and from the grinder, a guide device mounted upon the generally horizontal support and extending longitudinally thereof and projecting beyond one end of the rotary grinder, a carriage mounted upon the guide device, an adjusting .screW to move the carriage longitudinally of the guide device, a generally vertical post mounted upon the carriage and having a turning axis and projecting upwardly beyond the carriage, a head mounted upon the post to turn generally horizontally about the turning axis of the post, said head having a generally horizontal opening, a rock shaft extending through the generally horizontal opening, an adjustable stop mounted upon the rock shaft and having a part to engage with the head to limit the turning movement of the rock shaft, a handle mounted upon the outer end of the rock shaft, a clamp arranged opposite one end of the rotary grinder and mounted upon the rock shaft and having means for receiving and holding the bit so that the longitudinal axis of the bit is arranged generally at a right angle to the face of the end of 1

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