US3452625A

US3452625A - Drill

Info

Publication number: US3452625A
Application number: US595919A
Authority: US
Inventors: Peter Russo
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-11-21
Filing date: 1966-11-21
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01

Description

July 1, 1969 Y P. usso 7 3,452,625

DRILL Filed Nov. 21. 1966 INVENTOR PETER Russo ATTORNEY St. Louis, Mo. 63113 Filed Nov. 21, 1966, Ser. No. 595,919

Int. Cl. B23b 51/02 US. CI. 77-70 3 Clauns This invention relates in general to cutting tools, and more particularly, to a drill of the so-called twist type having a novel cutting portion.

It is an object of the present invention to provide a drill having twin cutting edges which are aligned transversely of the drill with an intervening U-shaped recess therebetween, providing a cutting portion which is relatively free of clogging during drilling operation.

It is another object of the present invention to provide a drill of the character stated which is relatively easily ground; which is designed to prevent hanging up of the cut metal; and which, during usage, substantially prevents over-heating.

It is further object of the present invention to provide a drill of the character stated, having a novel tip portion which efiects the drilling of frusto-conical holes in metallic sheet metal; which does not require the application of relatively great pressure for operation; and which substantially eliminates burring.

It is an additional object of the present invention to provide a drill of the character stated which is strong and durable in usage; which by reason of its unique configuration is capable of usage for relatively long periods of time without the necessity of sharpening; and which cuts relatively rapidly.

Other objects and details of the invention will be apparent from the following description, when read in connection with the accompanying drawings (1 sheet), wherein- FIGURE 1 is an end view of a drill constructed in accordance with and embodying the present invention.

FIGURE 2 is a side elevational view of the tip portion of the drill.

FIGURE 3 is a vertical transverse sectional view taken on the line 3-3 of FIGURE 2.

FIGURE 4 is an elevational view of the tip portion of the drill taken at an angle of 90 to the view thereof in FIGURE 2.

Referring now by reference characters to the drawing which illustrates the preferred embodiment of the present invention, A generally designates a drill of the twist type incorporating a cylindrical body 1, having a tip portion 2 formed on one end thereof. Body 1 is provided with at least 2 diametrally opposed

flutes

3, 4 with a corresponding number of intervening

lands

5, 6, the said flutes and lands being in conventional helical formation. The vallies of the

flutes

3, 4 being indicated 3', 4 respectively, constitute a part of the outer surface of the body portion. Body 1 may incorporate a smooth surface shank (not shown) in accordance with customary practice.

It is to be understood that drills having more than two flutes and two lands may be utilized in accordance with this invention, but two of each have been found preferable.

For orientation purposes, the term upwardly as used hereinbelow indicates the longitudinal direction toward tip portion 2 of drill A, while the term downwardly will be used to express the opposite longitudinal direction, that away from said tip portion 2. The term outwardly is used hereinbelow to indicate the direction radially outwardly or away from the longitudinal axis of drill A, with the term inwardly used to designate the reverse direction, that being radially toward the longitudinal axis of said drill A.

United States Patent 3,452,625 Patented July 1, 1969 Tip portion 2 of drill A is of symmetrical configuration about a transverse line indicated at XX, passing through the vallies 3', 4 of flutes 3, 4 (FIGURE 1); it being understood that a plane passing through said vallies would thus bi-sect drill A into two equal identical parts. Since the configuration of tip portion A on one side of line X-X is the same as on the other side thereof, for purposes of simplification, the structure on any one side thereof will be described, but with the understanding such description is equally applicable to such other side. In its upper terminal portion, land 5 is provided with a clearing surface 7 of generally triangular character defined by a leading or cutting edge 8, an inner or trailing edge 9 substantially normal to said cutting edge 8, and an outer arcuate peripheral edge 10. The point of juncture between cutting edge 8 and trailing edge 9 constitutes cutting point or corner 11, with said cutting point 11 and cutting edge 8, being in transverse alignment with the cutting point and cutting edge formed on land 6 as indicated respectively at 11' and 8'. Said cutting edges 8, 8' together with the

respective points

11, 11 are presented outwardly of the longitudinal axis of drill A or are laterally offset from dead center 12 of drill A. Trailing edges 9 of

said lands

5, 6 constitute the upper limits of an upwardly opening recess 13 of general U-shaped configuration in cross-section (see FIGURE 2), with said dead center 12, being located at the base of said U-form. Said recess 13, which may be readily formed by conventional grinding equipment incorporates downwardly and outwardly

inclined portions

14, 14 formed in the upper portions of said

lands

5, 6, respectively, adjacent the related trailing edge 9 to present secondary flutes. From the foregoing it will be seen that tip portion 2 is of symmetrical nature having twin cutting edges 8, 8' in transverse alignment which have trailing edges 9 which are presented outwardly of dead center 12 of drill A, being separated by a U-shaped recess 13; said edges 9 incline outwardly, in opposite directions, away from the center of drill A being in non-parallel relationship. It will be seen that the clearing surfaces 7 are inclined downwardly in opposite directions.

In operation, drill A is suited for drilling upon both sheet metal and relatively thick metal stock; being supported by a guide, as customary with jigs, to provide stability during usage. With drill A rotating in the direction of the arr-ow as shown in FIGURE 1, the said drill is lowered to the work with cutting points 11, 11', thus simultaneously making initial contact with the surface of the work at two spaced sites. As drill A is rotated, the said cutting points 11, 11' will bite or otherwise cut into the work for introduction thereinto of

cutting edges

8, 8. The angle of slope of said

cutting edges

8, 8 from their respective cutting points 11, 11' will cause a generally frustoconical opening to be developed in the work by the drilling or cutting action of said edges 8, 8', with the ultimate creation of an opening having its side walls perpendicular to the plane of the surfaces of the work. By reason of the unique generally U-shaped recess 13, cutting edges 8, 8' will effect, in sheet metal, the development of an integral Work fragment or plug, as it were, which may be bodily removed from the work, thereby preventing any clogging during the cutting action. With relative thin work pieces, there will, by reason of the unique, configuration of tip portion 2, be obviated the development of the customary chips and shavings as formed with drills known heretofore. Additionally, the provision of the twin cutting edges will militate against the development of heat so that the drill may operate for relatively extensive periods of time in a fully effective manner. With the two sharp cutting edges, 8, 8', the onset of dullness is relatively delayed so that said edges retain their cutting capability for relatively long periods. The unique nature of said tip portion 2 eliminates the need for applying substantial pressure during the cutting action as the said twin cutting edges 8, 8' act in the manner of a double drill bit. With the present invention, each cutting edge cuts relatively less metal but yet effects the total drilling procedure in a relatively rapid manner.

Drills formed in accordance with the present invention conduce to marked simplicity in the grinding operation thereby assuring that the desired configuration may be easily formed. It has been found that drills of the type herein set forth have marked durability so as to obviate the need for the frequency of grinding which has been encountered with drills heretofore utilized. The slope of the sides of the U-shaped recess 13 contributes substantially to the unusual properties of the present drill, rendering the same durable and resistant to dullness, as well as preventive of early over-heaving.

The said cutting edges 8, 8', together with the intervening recess 13, may be formed on tip portion 2 by the usual stone grinding wheel, the transverse extent of its peripheral face being slightly narrower than said recess 13.

It should be understood that changes and modifications in the formation, construction, arrangement, and combination of the several parts of the drill may be made and substituted for these herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A drill comprising a cylindrical body having at least two flutes in diametrically opposed relationship and two intervening lands, said flutes and lands being in helical formation, a tip portion provided on one end of said body, first and second cutting edges provided on said tip portion and being in transverse alignment, first and second trailing edges, each trailing edge being substantially normal to the adjacent cutting edge and being in nonparallel relationship with each other, said tip portion being symmetrically disposed about a plane passing transversely therethrough between said cutting edges bisecting said tip portion into two identical components, each such component having a clearing surface formed at the end of the related land, said first and second cutting edges defining one margin of the related clearing surface, said first and second trailing edges defining another margin of the related clearing surface, said clearing surfaces declining downwardly and outwardly from the junction between the related cutting edge and trailing edge, said junction defining a cutting point, said first second cutting edges being laterally offset with respect to the longitudinal axis of said body, there being a U-shaped recess between said cutting edges and transversely aligned therewith, said cutting points defining the upper limit of said U-shaped recess, means defining relatively short secondary flutes provided in the upper portion of each of said lands adjacent the related trailing edge and constituting inner lateral portions of said U-shaped recess, said recess having a base between said secondary flutes extending linearly transversely of said body.

2. A drill as defined in claim 1 and further characterized by said secondary flutes having inclined portions extending radially downwardly and outwardly of sad base.

3. A drill as defined in claim 2 and further characterized by said base being coincident with the dead center of said U-shaped portion.

References Cited UNITED STATES PATENTS 3,028,773 4/ 1962 Borneman 7770 2,334,089 1l/ 1943 Hallden 77-70 989,379 4/1911 Mather 77-70 FRANCIS S. HUSAR, Primary Examiner.

US. Cl. X.R. 117

Claims

1. A DRILL COMPRISING CYLINDRICAL BODY HAVING AT LEAST TWO FLUTES IN DIAMETRICALLY OPPOSED RELATIONSHIP AND TWO INTERVENING LANDS, SAID FLUTED AND LANDS BEING IN HELICAL FORMATION, A TIP PORTION PROVIDED ON ONE END OF SAID BODY, FIRST AND SECOND CUTTING EDGES PROVIDED ON SAID TIP PORTION AND BEING IN TRANSVERSE ALINGMENT, FIRST AND SECOND TRAILING EDGES, EACH TRAILING EDGE BEING IN NONNORMAL TO THE ADJACENT CUTTING EDGE AND BEING IN NONPARALLEL RELATIONSHIP WITH EACH OTHER, SAID TIP PORTION BEING SYMMETRICALLY DISPOSED ABOUT A PLANE PASSING TRANSVERSELY THERETHROUGH BETWEEN SAID CUTTING EDGES BISECTING SAID TIP PORTION INTO TWO IDENTICAL COMPONENTS, EACH SUCH COMPONENT HAVING A CLEARING SURFACE FORMED AT THE END OF THE RELATED LAND, SAID FIRST AND SECOND CUTTING EDGES DEFINING ONE MARGIN OF THE RELATED CLEARING SURFACE, SAID FIRST AND SECOND TRAILING EDGES DEFINING ANOTHER MARGIN OF THE RALATED CLEARING SURFACE, SAID CLEARING SURFACES DECLINING DOWNWARDLY AND OUTWARDLY FROM THE JUNCTION BETWEEN THE RELATED CUTTING EDGE AND TRAILING EDGE, SAID JUNCTION DEFINING A CUTTING POINT, SAID FIRST SECOND CUTTING EDGES BEING LATERALLY OFFSET WITH RESPECT TO THE LONGITUDINAL AXIS OF SAID BODY, THERE BEING A U-SHAPED RECESS BETWEEN SAID CUTTING EDGES AND TRANSVERSELY ALINGED THEREWITH, SAID CUTTING POINTS DEFINING THE UPPER LIMIT OF SAID U-SHAPED SRECESS, MEANS DEFINING RELATIVELY SHORT SECONDARY FLUTES PROVIDED IN THE UPPER PORTION OF EACH OF SAID LANDS ADJACENT THE RELATED TRAILING EDGE AND CONSTITUTING INNERLATERAL PORTIONS OF SAID U-SHAPED RECESS, SAID RECESS HAVING A BASE BETWEEN SAID SECONDARY FLUTES EXTENDING LINEARLY TRANSVERSELY OF SAID BODY.