Cone mouth debris exclusion shield
AssigneeDresser Industries, Inc.
InventorTheodore R. Dysart
Life of this patent
Estimating the term…
Abstract
A rotary drill bit having a body with a projecting journal and a conical cutter having an axially recessed open end for receiving the journal wherein only the upper portion of the open cone mouth in the cavity formed between the cone and the body is shielded from drilled debris intrusion and the circulating air is channeled in the bearing to the bottom portion of the open cone mouth for improved flow pattern through the various bearing segments whereby the incidence of plugging of the bit due to excess formation being forced into the bearing at the gaping open portion of the upper cone mouth is reduced.
Claims14
In a rotating drill bit having a body with a projecting journal, a conical cutter having an axially extending recess open at one end for receiving said journal, interior anti-friction bearings in said cutter for rotatably mounting said cutter on said journal in spaced relationship with said journal, and a plurality of fluid carrying passages in said journal extending to said bearings, said fluid exiting said recess through said open end, the improvement comprising:
- a. a shoulder on said cutter in spaced relationship with said body, and
- b. blocking means in resilient abutting relationship between said cutter and said body for closing an arcuate portion of said space between said body and said shoulder on the upper side of said journal to prevent debris from entering the open end of said cutter through said space between said shoulder and said body on the upper side of said journal and said fluid is forced to exit the open end from the remaining open space between said body and said shoulder not closed by said blocking means thereby preventing debris from entering said open space.
A method of reducing bearing wear in a rotary drill bit having a body with a projecting journal, a conical cutter having an axially extending recess open at one end for receiving said journal, interior anti-friction bearings in said cutter for rotatably mounting said cutter in spaced relationship with said journal, forming a cavity between one portion of said body and said conical cutter on the upper side of said journal by mounting said cutter on said journal and a plurality of fluid carrying passages in said journal extending to said bearings, said fluid exiting said recess through said open end, said method comprising the steps of:
- a. forming a shoulder on said cutter in spaced relationship with said body, and
- b. locating blocking means in resilient abutting relationship between said cutter and said body for closing an arcuate portion of said space between said body and said shoulder on the upper side of said journal to prevent debris from entering the open end of said cutter through said space between said shoulder and said body on the upper side of said journal and said fluid is forced to exit the open end from the remaining open space between said body and said cutter shoulder not closed by said blocking means thereby preventing debris from entering said open end through said remaining open space.
Dependencies are inferred from the claim text.