Combination rotary and percussion drill bit

Claim 2

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally frustoconical sidewall section extending between the narrow point of the body and the larger cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the frustoconical surface thereof, said inserts being arranged substantially symmetrically in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof, and the spacing between adjacent inserts being less than the width of said inserts; and e. hardened means on the point for fracturing such brittle material as may be encountered during drilling.

Claim 3

The drill bit as claimed in claim 1 wherein the hardened means on the point comprises a plurality of hardened inserts which are mounted so as to form effective extensions of the helical rows of hardened inserts on the frustoconical section.

Claim 4

The drill bit as claimed in claim 1 wherein the ratio of base diameter to point diameter lies within a range of about 2 to about 7, and wherein the included angle of the generally frustoconical section is within the range of about 20* to 80*.

Claim 5

The drill bit as claimed in claim 1 wherein the included angle of the generally conical section is approximately 34*.

Claim 6

The drill bit as claimed in claim 1 wherein each of the hardened inserts comprise metallic carbide inserts having a generally cylindrical body which is pressed into respective apertures in the bit body, and the distance between adjacent hardened inserts is at least one sixteenth inch but less than the diameter of the inserts.

Claim 7

The drill bit as claimed in claim 1 wherein a helical groove is provided in the surface between each two adjacent rows of hardened inserts, with the groove beginning at a point along the cylindrical base and terminating at a point at least half way from the base toward the point, with said grooves being adapted to cooperate with the hardened inserts to force cuttings around and past the bit during rotary movement thereof.

Claim 8

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof; e. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and f. a transition surface extending between the relatively flat point and the generally conical section, said transition surface comprising a generally frustoconical surface with an included angle of about 120*.

Claim 9

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof; e. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and f. a transition surface extending between the relatively flat point and the generally conical section, said transition surface comprising a generally frustoconical surface with an included angle of about 120*.

Claim 10

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof; e. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and f. there being three surface grooves winding around the bit between three helical rows of hardened inserts mounted on the bit, and the plurality of hardened inserts on the point comprise fOur inserts which are arranged with three at the corners of an isosceles triangle and the fourth is at the center of the triangle.

Claim 11

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof; e. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and f. there being three surface grooves winding around the bit between three helical rows of hardened inserts mounted on the bit, and the plurality of hardened inserts on the point comprise fOur inserts which are arranged with three at the corners of an isosceles triangle and the fourth is at the center of the triangle.

Claim 12

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof, and wherein the hardened inserts are spaced on the conical section in such a way that the quantity of inserts is greater as the diameter of the conical section increases, as measured from the point to the base; and e. hardened means on the point for fracturing such brittle material as may be encountered during drilling.

Claim 13

A combination rotary and percussion drill bit, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated; b. a substantially cylindrical base having one or more hardened inserts protruding radially therefrom, said base and its inserts being adapted to serve as a gauging member, and said base having both means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward; c. a generally conical section extending between the point of the body and the cylindrical base thereof; d. a plurality of hardened inserts mounted on the bit and protruding outwardly from the conical surface thereof, said inserts being arranged in helical rows extending from the point to the base, and each row winding at least 120* around the bit as it traverses the distance from the point to the cylindrical base, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to urge cuttings around and past the bit during rotary movement thereof, and wherein the hardened inserts are spaced on the conical section in such a way that the quantity of inserts is greater as the diameter of the conical section increases, as measured from the point to the base; and e. hardened means on the point for fracturing such brittle material as may be encountered during drilling.

Claim 14

A drill bit adapted for use in percussion drilling apparatus, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated, and a substantially cylindrical base having means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward, and a relatively narrow and generally frustoconical sidewall section extending between the point and the cylindrical base, with the ratio of the base diameter to the point diameter being within the range of about 7 to 2, and further including a frustoconical transition surface lying between the relatively flat point and the frustoconical sidewall section, and the included angle of said frustoconical transition surface being about 120*; b. a plurality of hardened inserts mounted on the bit and protruding outwardly from the frustoconical sidewall section, said inserts being arranged in helical rows of a substantially uniform pitch extending from the point to the base, and each row winding partially around the bit as it traverses the distance from the point to the cylindrical base, with the arrangement of inserts in the rows being substantially the same, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to guide cuttings around and past the bit during rotary movement thereof; c. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and d. a hard metallic coating on the body which at least covers the juncture of the hardened inserts and the body, whereby the body is protected from excessive wear at the sensitive locations where the hardened inserts are mounted.

Claim 15

A drill bit adapted for use in percussion drilling apparatus, comprising: a. a substantially solid body having a relatively narrow and flat point which is adapted to make initial contact with the matter to be penetrated, and a substantially cylindrical base having means against which torque forces may be applied and means against which axial forces may be applied, whereby the bit may be both rotated and driven axially forward, and a relatively narrow and generally frustoconical sidewall section extending between the point and the cylindrical base, with the ratio of the base diameter to the point diameter being within the range of about 7 to 2, and further including a frustoconical transition surface lying between the relatively flat point and the frustoconical sidewall section, and the included angle of said frustoconical transition surface being about 120*; b. a plurality of hardened inserts mounted on the bit and protruding outwardly from the frustoconical sidewall section, said inserts being arranged in helical rows of a substantially uniform pitch extending from the point to the base, and each row winding partially around the bit as it traverses the distance from the point to the cylindrical base, with the arrangement of inserts in the rows being substantially the same, and the protruding inserts in a given row being closely spaced to effectively establish an elevated ridge which is adapted to guide cuttings around and past the bit during rotary movement thereof; c. hardened means on the point for fracturing such brittle material as may be encountered during drilling; and d. a hard metallic coating on the body which at least covers the juncture of the hardened inserts and the body, whereby the body is protected from excessive wear at the sensitive locations where the hardened inserts are mounted.