US2119741A

US2119741A - Drill grinding tool

Info

Publication number: US2119741A
Application number: US132696A
Authority: US
Inventors: William H Fischer
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-03-24
Filing date: 1937-03-24
Publication date: 1938-06-07
Anticipated expiration: 1955-06-07

Description

June 7, 1938. w H. FISCHER DRILL GRINDING TOOL Filed March 24, 1937 Patented June 7, 1938 UNITED STATES PATENT O F 7 1 Claim.

One object of this invention is the provision of a drill grinding tool adapted to be mounted on a standard adjacent the grinding wheel, and so constructed and designed that it may be quickly and deftly manipulated to turn the drill through an arc of 180 degrees so as to have first one cutting edge of the drill against the wheel and then the opposite cutting edge with positive assurance that both edges willbe ground true.

Another object of the invention is the provision of such a device with means for feeding the drill toward the wheel and for retracting the drill from the wheel in a very fine degree of movement, so as to avoid too great an advance toward the wheel when such adjustment is desired, and thereby prevent damage to either the wheel or the drill.

The above and other objects will become apparent in the description below, in which characters of reference refer to like-named parts in the accompanying drawing.

Referring briefly to the drawing, Figure 1 is a plan view of the device mounted on a standard bearing the grinding wheel.

2 Figure 2 is a fragmentary side elevational view of Figure 1, with the tool in grinding position.

Figure 3 is a view similar to Figure 2, with the tool in elevated position prior to rotation thereof through an arc of 180 degrees.

30 Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 1.

Figure 5 is a cross-sectional view taken on the line 55 of Figure 2.

Figure 6 is a cross-sectional View taken on the 35 line 6-6 of Figure 4.

Figure 7 is a front elevational view of the device.

Referring in detail to the drawing, the numeral It indicates a standard on which a rotat- LO able grindstone, emery wheel, or the like II is mounted. A fastening screw or the like I2 is provided on the standard In for securing the grinding tool thereto.

The tool embodies a rectangular frame l3 hav- 5 ing an opening I4 passing therethrough. The lower member I5 of the frame I3 is extended angularly rearward of the frame 13 and formed into a yoke l6 by means of which the device may be secured by the screw l2 to the standard 0 Ill. Screws I! pass through the sides of the frame I3 near the top thereof, and have tapered ends l8 which serve as pivots or trunnions for a block l9 provided with complementary openings in which the trunnions l8 register, thus 5 causing the block l9 to be pivotably suspended diametrically opposite points with indentations 5 7 2|. In the corner or edge of the block l9, a

channel 22 extending substantially radially with respect to the sleeve 26, is provided through the block IS. A pin 23 is slidably mounted in the channel 22 and urged toward the sleeve 20 by 10 a spring 24. The tapering extremity of the pin 23, as well as the tapering form of the indentations 2|, permits releasable locking of the sleeve 20 against rotation when the rotating force applied to the cap is relatively light, but 15 permits the sides of the indentations 2| to force the pin 23 out of the same, with consequent rotation of the sleeve, when the rotating force is relatively strong.

The sleeve 26 is provided with an extending 0 externally threaded body 25 which threadably receives a barrel 26. open at both ends. A rigid pin 21 projects internally into the barrel at a point intermediate its length. The outer surface of the barrel 26 is knurled. A stud 28 having a 25 rigid collar 29 intermediate its length, is mounted in the rear of the barrel 26 with oneend 30 projecting outward through the rear opening 3! of the barrel. Both the forward end 32 and the rearward end 30 of the stud 28, are'threaded. 30 A reduced knob 33 whose outer surface is also knurled, is tightly screwed on the stud end 30 and locked therein by a pin 40 so that the stud 28 is locked thereon and rotates unitarily with the knob 33.

A hollow stem 34 has its rear end 35 enlarged and provided on its outer surface with a longitudinal slot 36 in which the pin 27 registers. The end 35 of the stem 36 is internally threaded and engageable on the forward end 32 of the 40 stud 38. It is to be noted that because of the engagement of the pin 21 in the slot 36, rotation of the stud 28 by the knob 33 will cause the stem 34 to moveforward or backward along 7 its axis. A spring 3'! surrounds the stem 34 be- 4 tween the body 25 of the sleeve 26 and the shoulder formed by the junction of the stem 34 with its enlarged end 35. This spring normally urges the stem 34 rearward from the sleeve 26. At the forward end of the stem '34, a chuck 33 is provided which is of standard construction and serves to receive and locktherein the drill which is to be ground. The manner of assembling the entire tool is obvious from the above. In use, the drill 39 is 5 locked in the chuck 38 after the device has been secured to the standard Ill. The relative position of the tool with respect to the wheel II is roughly adjusted by means of the screw l2 and the yoke l6. Fine adjustment in advancing or retracting the drill from the wheel is made by rotation of the knob 33.

To obtain correct results in sharpening a drill, both surfaces of the drill must be ground exactly alike from the center. Usually this is a hit-and-miss matter, especially in grinding small drills. To use the tool described, the cutting edge of the drill is placed in horizontal position, and the drill is advanced slowly to the wheel H by turning the knob 33, and one cutting edge of the drill is ground. The tool is then swung downward on its pivots 18 to carry the drill clear of the wheel. The barrel 26 is then rotated through half a turn, which is checked without any possibility of doubt by the clicking of the pin 23 as it snaps into the diametrically opposite indentation 2|. Then the tool with its opposite edge facing the wheel, is again advanced to the wheel by means of the knob 33. Thus, proper and accurate grinding of both opposite edges of the drill is assured.

Obviously, modifications in form and structure may be made without departing from the spirit and scope of the invention.

I claim:

A drill grinding tool comprising a substantially rectangular upright frame, means for securing said frame on a standard, a block pivotally suspended within said frame, said block having a circular opening therethrough in the upper portion thereof, a sleeve rotatably mounted in said opening, a barrel secured to and extending axially rearward of said sleeve, a stem slidably mounted in said sleeve and having a chuck on its forward end, a knob rotatably mounted at the rear end of said barrel, means between said stem and said knob for advancing or retarding said stem upon rotation of said knob, said sleeve having a pair of oppositely disposed cone-shaped indentations on its outer surface within said block, a tapered pin slidably mounted in said block and projecting substantially radially into said opening, a spring urging said pin toward said opening, said pin being adapted to register alternately in said indentations.

WILLIAM H. FISCHER.