Drill bit screw tip
AssigneeIrwin Industrial Tool Company
InventorLaverne R. Durfee
Life of this patent
Estimating the term…
Abstract
A drill bit comprises a shank having a longitudinal axis. A cutting head is formed at one end of the shank. A removable and replaceable pilot tip such as a screw tip or pilot point is formed on the cutting head. The pilot tip is designed for controlled failure. A tool is also provided for removing the broken tip. A kit comprising a dill bit adapted to receive a removable tip, a removable tip for attachment to the cutting head, and/or a removal tool for removing a broken tip from the drill bit. A method for removing a tip from a drill bit and replacing it with another tip is also provided.
Claims13
A drill bit comprising:
- a shaft;
- a cutting head formed on the shaft;
- a removable tip having a stem and a leading end, said stem threadably engaged with a threaded bore formed in the cutting head, said removable tip having a controlled break point between the stem and the leading end where the tip will break if a force above a predetermined force is applied to the tip wherein the cutting head has a cutting edge and said controlled break point is arranged from a point substantially flush with the cutting edge toward the shaft, the controlled break point comprising a narrow web that includes a flat face arranged such that a cavity is created between the flat face and the threaded bore that is dimensioned to receive a tool, said cavity being covered by said tip.
A kit comprising:
- a drill bit having a cutting head formed with a threaded bore adapted to receive a removable tip;
- a removable tip having a stem and a leading end, said stem threadably engaged with said threaded bore, said removable tip having a controlled break point between the stem and the leading end where the tip will break if a force above a predetermined force is applied to the tip wherein the cutting head has a cutting edge and said controlled break point is arranged from a point substantially flush with the cutting edge toward the shaft, the controlled break point comprising a narrow web that includes a flat face arranged such that a cavity is created between the flat face and the threaded bore that is dimensioned to receive a tool, said cavity being covered by said tip and a removal tool dimensioned to fit into said cavity for removing a broken stem from the threaded bore.
A method for removing a tip from a drill bit comprising:
- providing a cutting head having a bore on the drill bit;
- providing a removable tip having a stem extending into said bore;
- providing a controlled break point on the tip, said controlled break point comprising a narrow web that includes a flat face;
- defining a cavity arranged between the flat face and the threaded bore that is dimensioned to receive a tool;
- inserting a tool into said cavity to remove the tip from the cutting head;
- and
- inserting another tip into the cutting head.
Dependencies are inferred from the claim text.