PDC bit element with retention feature
A drill bit includes a bit body, one or more blades forming part of the bit body, a plurality of cutter pockets defined in the one or more blades, each cutter pocket providing a floor and an orifice defined in the floor, and a plurality of cutters secured to the one or more blades at the plurality of cutter pockets. Each cutter includes a substrate, a diamond table secured to the substrate at an interface, and a retention feature extending from a bottom surface of the substrate and sized to be received within the orifice of a corresponding one of the plurality of cutter pockets.
1 . A drill bit, comprising:
a bit body;
one or more blades forming part of the bit body;
a plurality of cutter pockets defined in the one or more blades, each cutter pocket providing a floor and an orifice defined in the floor; and
a plurality of cutters secured with braze to the one or more blades at the plurality of cutter pockets, each cutter including:
a substrate;
a diamond table secured to the substrate at an interface; and
a retention feature extending from a bottom surface of the substrate and providing a cylindrical sidewall parallel to a sidewall of the substrate, the retention feature being sized to be received within the orifice of a corresponding one of the plurality of cutter pockets,
wherein the cylindrical sidewall extends at a constant first diameter between the bottom surface of the substrate and a bottom face of the retention feature, the bottom face being perpendicular to the cylindrical sidewall, and
wherein the constant first diameter is smaller than a diameter of the sidewall of the substrate.
2 . The drill bit of claim 1 , wherein the retention feature comprises a cylindrical body extending concentric with a central axis of the cutter.
3 . The drill bit of claim 1 , wherein the retention feature comprises an integral extension of the substrate.
4 . The drill bit of claim 1 , wherein a diameter of the retention feature is 80% or less than a diameter of the substrate.
5 . The drill bit of claim 1 , wherein the bottom face of the retention feature extends in a plane substantially parallel with a plane extending through the bottom surface of the substrate.
6 . The drill bit of claim 1 , wherein the retention feature is received within the orifice via an interference fit.
7 . The drill bit of claim 1 , wherein the retention feature is loosely received within the orifice.
8 . The drill bit of claim 1 , wherein each cutter is received within a corresponding one of the plurality of cutter pockets such that the bottom face abuts against at least a portion of a distal end of the orifice.
9 . The drill bit of claim 1 , wherein a portion of the sidewall of the substrate extends above a top face of the blade, and wherein the orifice is entirely defined in the floor below the top face of the blade.
10 . A method of securing a cutter to a cutter pocket of a drill bit, comprising
receiving the cutter in the cutter pocket, the cutter including:
a substrate;
a diamond table secured to the substrate at an interface; and
a retention feature extending from a bottom surface of the substrate and providing a cylindrical sidewall parallel to a sidewall of the substrate;
centering the cutter within the cutter pocket by receiving the retention feature in an orifice defined in a floor of the cutter pocket; and
attaching the cutter in the cutter pocket with braze while the retention feature is received within the orifice,
wherein the cylindrical sidewall of the retention feature extends at a constant first diameter between the bottom surface of the substrate and a bottom face of the retention feature, the bottom face being perpendicular to the cylindrical sidewall of the retention feature, and
wherein the constant first diameter is smaller than a diameter of the sidewall of the substrate.
11 . The method of claim 10 , further comprising holding the cutter in place during attaching with the retention feature received within the orifice.
12 . The method of claim 10 , further comprising preventing floating of the cutter within the cutter pocket during attaching with the retention feature received within the orifice.
13 . The method of claim 10 , wherein receiving the cutter in the cutter pocket is preceded by milling the orifice into the floor of the cutter pocket.
14 . A method of manufacturing a cutter for a drill bit, comprising:
securing a diamond table to a first end of a substrate; and
providing a retention feature on a second end of the substrate opposite the first end,
wherein the retention feature comprises a body and a sidewall parallel to a sidewall of the substrate and extends at a constant first diameter between the bottom surface of the substrate and a bottom face of the retention feature, the bottom face being perpendicular to the sidewall of the retention feature,
wherein the constant first diameter is smaller than a diameter of the sidewall of the substrate, the retention feature being sized to be received within an orifice defined in a floor of a cutter pocket of the drill bit,
wherein the cutter is configured to be secured with braze to the cutter pocket along at least a portion of the sidewall of the substrate.
15 . The method of claim 14 , wherein the body exhibits a cross-sectional shape selected from the group consisting of circular, oval, ovoid, polygonal, gear-toothed, and any combination thereof.
16 . The method of claim 14 , wherein providing the retention feature on the second end comprises aligning the body concentric with a central axis of the cutter.
17 . The method of claim 14 , wherein providing the retention feature on the second end comprises forming the retention feature on the second end as integral extension of the substrate.
18 . The drill bit of claim 14 , wherein the cutter pocket is defined in a blade of the drill bit, and wherein the portion of the sidewall of the substrate extends above a top face of the blade, and wherein the orifice is entirely defined in the floor below the top face of the blade.
19 . The drill bit of claim 14 , wherein the portion of the sidewall of the substrate is located above a top of the orifice.
20 . A method of retrofitting a drill bit, comprising
forming an orifice defined in a floor of a cutter pocket;
receiving a cutter in the cutter pocket, the cutter including:
a substrate;
a diamond table secured to the substrate at an interface; and
a retention feature extending from a bottom surface of the substrate and providing a cylindrical sidewall parallel to a sidewall of the substrate,
wherein the cylindrical sidewall of the retention feature exhibits a constant first diameter between the bottom surface of the substrate and a bottom face of the retention feature, the bottom face being perpendicular to the cylindrical sidewall,
wherein the constant first diameter is smaller than a diameter of the sidewall of the substrate;
centering the cutter within the cutter pocket by receiving the retention feature in the orifice, wherein the bottom surface contacts the floor when the retention feature is received within the orifice; and
attaching the cutter in the cutter pocket with braze while the retention feature is received within the orifice.