Method of selecting a drilling bit
OwnerDavid Rees MUGELIinventor
Life of this patent
Estimating the term…
Abstract
A drill bit includes a shank having a wasted shear safety section. Each bit is color coded to different shear safety ratings. The shank is fattened at the chuck end with flats extending on both sides of the wasted section. Safety ratings relate to the risk associated with different drilling situations and user expertise.
Claims17
A method of selecting a rotary bit from a plurality of rotary bits according to a classification of risk related to the intended use of the bit, each of the plurality of bits being the same except for a predetermined shear force rating, the method comprising:
- selecting a rotary bit having a shank with an insert end and an end section extending from the insert end, the end section having at least one elongate flat which locates inside a chuck when the shank is operatively engaged in the chuck;
- selecting the rotary bit having a wasted safety section spaced from the insert end by a spacing, the spacing of the wasted safety section from the insert end being sufficient so that when the shank is operatively engaged in the chuck, the wasted safety section is outside the chuck;
- and
- selecting the bit based on a classification of risk related to the intended use of the bit, so that the shank shears at the wasted safety section if the predetermined shear torque rating is exceeded.
A method of selecting a rotary bit from a plurality of rotary bits according to a classification of risk related to the intended use of the bit, each bit being the same except for a predetermined shear torque rating, said method comprising:
- selecting a rotary bit having a wasted safety section spaced from an insert end by a spacing, the spacing of the wasted safety section from the insert end being sufficient so that when a shank of the bit is operatively engaged in a chuck, the wasted safety section is outside the chuck;
- and
- selecting the bit based on a classification of risk related to the intended use of the bit, so that the shank shears at the wasted safety section if the predetermined shear torque rating is exceeded.
A method of selecting a set of rotary bits from a plurality of sets of rotary bits according to a classification of risk related to the intended use of each set of bits, at least one bit from each of said sets being the same except for a predetermined shear torque rating, the method comprising:
- selecting a set of rotary bits each having a shank with an insert end and an end section extending from the insert end, the end section having at least one elongate flat which locates inside a chuck when the shank is operatively engaged in the chuck;
- selecting the set of rotary bits each having a wasted safety section spaced from the insert end by a spacing, the spacing of the wasted safety section from the insert end being sufficient so that when the shank is operatively engaged in the chuck, the wasted safety section is outside the chuck;
- and
- selecting said set of bits based on a respective predetermined shear torque rating for each wasted safety section according to a classification of risk related to the intended use of the bit, so that the shank shears at the wasted safety section if the predetermined shear torque rating is exceeded.
Dependencies are inferred from the claim text.