US2746212A - Grinding assembly for drill bits - Google Patents

Description

3 y 2, 1956 c. K. JENSCH 2,746,212

GRINDING ASSEMBLY FOR DRILL. BITS Filed July 26, 1951 4 Sheets-Sheet 1 J770ewz0r 1 C(yde Ji Jezasck May 22, 1956 c. K. JENSCH 2,746,212

GRINDING ASSEMBLY FOR DRILL BITS Filed July 26, 1951 4 Sheets-Sheet 2 flizarrzeys May 22, 1956 c. K. JENSCH 2,746,212

GRINDING ASSEMBLY FOR DRILL BITS Filed July 26, 1951 4 Sheets-Sheet 3 May 22, 1956 c. K. JENSCH GRINDING ASSEMBLY FOR DRILL BITS 4 Sheets-Sheet 4 Filed July 26, 1951 I7? we)? 202 iiyde K Jeiasc5 ifearzzqys United States Patent GRINDING ASSEMBLY non DRILL BrrS Clyde K. Jensch, Elm Grove, Wis, assignor to Nordberg Manufacturing Company, Milwaukee, Wis., 21 corpora tion of Wisconsin Application July 26, 1951, Serial No. 238,727

1 Claim. (Cl. 51-92) My invention relates to an improvement in tool sharpeners and has for one purpose to provide an apparatus upon which tools or bits can be quickly and easily and accurately sharpened.

Another purpose is to provide a grinding assembly in which tools or elements to be faced or sharpened or surfaced are manually moved to a predetermined position or at a predetermined angle across the moving surface of one or more grinding elements.

Another purpose is to provide a grinding assembly adapted for rapid grinding or finishing of tools or bits where intersecting surfaces are to be ground.

Other purposes will appear from time to time in the course of the specification and claim.

I illustrate the invention more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a perspective view of the assembly with certain of the parts removed;

Figure 2 is a perspective view from another point of observation illustrating the parts assembly with one alternative working part or carriage in use;

Figure 3 is a partial plan view with parts in section;

Figure 4 is a plan view of a working attachment;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a section on the line 6-6 of Figure 4;

Figure 7 is a partial sectional view taken on the line 7-7 of Figure 3 illustrating the working attachment of Figure 4 in place.

Figure 8 is a plan view of another working carrier or attachment;

Figure 9 is an end view of the structure of Figure 8;

Figure 10 is a section on the line 10-10 of Figure 9; and

Figure 11 illustrates a bit or tool to be sharpened.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, I illustrate a base plate 1 which may, for example, be mounted on or carried by a pair of transversely extending tubes 2. Mounted on the base plate 1 is any suitable motor block 3, the details of which do not of themselves form part of the present invention. It will be understood that any suitable motor means may be employed, but that I illustrate generally the gasoline engine 4, which drives a pulley 5, about which passes a belt 6. Likewise supported on the base plate 1 is a support 7, from which upwardly extends a Y-shaped supporting element 8, upon which is rotatably mounted a shaft or shafts 9, with which are rotatable grinding wheels 10, 10', of which two are shown. The pulley ll, connected to the shaft or shafts 9, is driven by the belt 6 whereby, in response to normal operation of the motor 4, the grinding wheels 10, 10' are rotated at suitable speed. Each such wheel is shown as surrounded by a suitable guard 12, 12', these guards being mounted on any suitable bases or supports 13, 13'.

The Y-shaped member 8 is shown as carrying or including two spaced sleeves 14, 14 adapted to receive the two rods 16, 16' of the supporting member 15. The supporting member 15 may be held in adjusted position for assembly by set screws 17, 17 associated with the sleeves 14, 14. The member, or support, or guide 15 is shown as having an outwardly spaced wall member or side member 18 which has exteriorly mounted on it rollers 19 and 20 and carrying also the internally mounted roller 21. With the parts assembled as shown in Figure 2, the axes of the three rollers are horizontal and the rollers have their peripheries extending to the same height or plane. They are adapted and positioned to support a grooved member or tracked member, such as is indicated at 25, for horizontal movement along a path across the grinding Wheel 10.

While I do not limit the structure herein shown to work with any particular cutting tools, it is particularly adapted to sharpen or service cutters of the type illustrated, for example at 26, and shown in perspective in Figure 11, such cutter having longitudinal flanges 26a, 26b, the two flanges being aligned along opposite sides of the cutter or bit.

In order to sharpen various faces of the bit 26, I illustrate two different carriers. The carrier 25 is formed with an upper slot 25a, which receives the lower flange 26b in guiding relationship. As will be clear from Figure 4, the guiding slot is at an angle, so that the bit will be beveled at one side of its cutting end if the carrier 25 is traversed across the path to which it is constrained by the rollers. In this operation the end of the bit engages and is ground by the periphery of the grinding wheel 10, which operation is shown in Figure 2.

As will be seen in Figure 7, the carrier 25 has a bottom track channel indicated at 25b which receives the rollers 19 and 26. It has also a flat track flange 250, which rests upon the inner roller 21. Thus the operator, when he has positioned the bit 26 as shown in dotted line in Figure 7 or as shown in full line in Figure 2, can traverse the bit across the grinding wheel 10. As will be seen in Figure 7, the bit 26 does not lie in a horizontal plane, but is slightly inclined. It will be understood that after one end bevel is cut, the operator can then turn the bit up side down and cut the opposite bevel.

The bit can be adjustably positioned on the carrier 25, for example by the adjusting screw 27, which is controlled by a knurled knob 27a, and passes through any suitable split holding block 28 controlled by the locking member 28a. Thus the operator can easily adjust the screw 27 and then lock it in place by rotating the locking member 28a. Thus the tools or bits may be cut to precisely the same length, as well as to precisely the same angle, as the carrier 25 is traversed across the peripheral grinding surface of the grinding disk 10.

In order to cut or form edges or cuts to complete the cutting edge of the tool, I provide a second carrier 30. It has at one side a channeled track 30a which rides on and is guided by the rollers 19 and 20, it being understood that an additional fiat track or bearing surface 30b is provided, as shown in Figure 9, to ride on the roller 21. In other words, both carriers can readily manually be traversed through a predetermined uniform path, whereby the bit or tool is always presented to the grinding wheel at a predetermined controlled angle.

The carrier 39 is shown as including the guide flange 31 with a plane guiding surface 31a broken by a channel 31!). The parts are so proportioned that the channel 311) receives either of the ridges 26a or 26b of the bit 26, to be sharpened. It is shown in Figures 8, 9 and 10 as clamped by a clamping lever 32 which may be pivoted, as at 33, to or between webs 34 of the carrier 30. It may be urged toward locking position, for example, by the bolt 35, the head of which is received between flanges 36 extending rearwardly from the lever 32. Any suitable means, such as the thumb nut 37, may be employed for locking the 3 bolt 35 with the parts in locking position, the bolt passing through any suitable aperture 38 in the guiding flange 31. 40 indicates a stop having an inclined face 41 to receive the end ofthe bit 26. Thus the bit may readily be clamped inposition in a predetermined relationship between the end, of the bit and the grinding wheel 10, as shown in Figure9. In this position it may then be urged against the side of the grinding Wheel 10 in order to cut the lateral indentation 260 or 26d which completes the cutting-edge of the tool: or bit, as shown in Figure 11.

Itwillbe realized that whereas I have described and shown a practical and operative device, nevertheless many changes may be madein size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish, my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than. as limiting me to my specific disclosure herein. It will be understood, for example, that v whereas I illustrate a structure adapted for a predetermined sharpening or forming of a particular tool or bit, my structure may by slight changes be adapted to-operate for the sharpening surfaces or grinding of a variety of bits or tools.

The use and operation of my invention are as follows:

I provide a readily portable, easily handled unit, which includes a small motor and at least one grinding disk or wheel driven thereby. The supports 15 and 18, as shown in Figures 1 and 2, can be adjusted toward and away from the cutting path of the grinder. Thus grinder wear or changes in size of grinding disks can be compensated for.

The three rollers or wheels 19, 20 and 21 constitute a three-point support for a carrier. I illustrate two carriers, each designed and formed to present a bit or tool for movement along a predetermined path toward the cutter. The carrier is traversed along a predetermined path guided or controlled by the three rollers. Taking first the use of the carrier 25, the screw 27 constitutes an outward positioning abutment which. may be adjusted, at the desire of the operator, toreceive the outer end of the bit. Assuming that the tools or bits as they come from stock are all of a uniform length, the abutment or positioning screw 27 would be located in a relatively Withdrawn position. But if used tools or bits are being resharpened, the abutment can be adjusted to any desired position to take the initially shorter bits. Since the bit or tool itself has positioning ribs, it is readily guided by corresponding guiding channels in the carrier.

Where it is desired to present the bit to the grinder from a difierent angle, to side-grind the surfaces 26c and 26d, I employ the carrier 30. Here again the bit is positioned by a channel 31b which guides or controls the position or angle of the bit in relation to the grinder. In the use of the carrier 30, as shown for example in Figure 9, the bit is fed against the forward abutment or stop 40, 41,

which limits the movement of the bit into the path of the cutting wheel 10. The bit is then moved laterally against the cutting wheel, by traversing the carrier, to cut the surface 260 or 26d. The rollers 19, 20 and 21 are preferably provided with any suitable anti-frictional bearings, so that a minimum of force is required to traverse the carriers. This is done manually and can be done very quickly. A substantial number of bits can be sharpened or ground in sequence.

I claim:

In a grinding assembly for drill bits and the like, a base and a grinding wheel mounted on said base for rotation about a predetermined axis, motor means on said base for rotating said grinding wheel, said base including spaced sleeves extending generally perpendicularly to the axis of said grinding wheel, a pair of rods inserted in said sleeves and means for holding said rods within said sleeves, a guiding support joined to said rods. andextending in front of said grinding wheel, said guiding support including spaced roller elements journaled for rotation about axes generally parallel to the axes of said sleeves, a bit carriage having downwardly extending guide track means engageable with said rollers for movement of the carriage along a line generally parallel to the axis of said wheel, said carriage being removable from said rollers upon upward movement therefrom, said carriage including an upstanding portion with, a substantially plane guiding surface, the plane of said surface extending generally parallel to the axes of said rods, said guiding surface having a channel formed therein. for receiving the ridge of abit positioned against said surface, an adjustable clamping lever on the carriage and cooperable with said surface for clamping a bit therebetween, and a, stop on said car,- riage between said wheel and said carriage, said stop being in the path of a bit positioned against said surface but spaced from the axis of said channel, movement of said carriage along said rollers being efiective. to force said bit against the side of said wheel.

References Cited in the file of this patent UNITED STATES PATENTS 523,897 Kenyon July 31, 1894 981,810 Sterling Jan. 17, 1911 1,101,593 Wagner June 30, 1914 1,110,366 Wincrantz Sept. 15, 1914 1,522,465 Kimmel Jan. 6, 1925 1,539,829 Cole June 2, 1925 1,915,247 Holloway et al June 20, 1 933 2,083,682 Balsiger et al June 15, 1 937 2,087,304 Sawyer July 20, 1937 2,460,491 Cooke Feb. 1, 1949 2,536,823 Smith Jan. 2, 1951 2,619,779 Kristenson Dec. 2, 1952

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