SYSTEM AND METHOD FOR LEG RETENTION ON HYBRID BITS
An earth boring drill bit comprising: one or more legs; a bit body having a blade and a slot for receiving the leg; and one or more wedge between the leg and the slot fixing the leg within the slot. The slot may have two parallel sidewalls with one of the sidewalls forming an acute angle and the other forming an obtuse angle. The wedge may be secured immediately next to the obtuse angled sidewall. The wedge may have two obtuse angled sides. One or more bolts through each wedge may secure both the wedge and the leg to the bit body. In a preferred embodiment, an obtuse angled sidewall of the wedge is preferably secured immediately next to an acute angled side of the leg.
1 . An earth boring drill bit comprising:
one or more legs;
a bit body having a slot for receiving the leg; and
one or more wedge between the leg and the slot fixing the leg within the slot.
2 . The bit of claim 1 , wherein the slot has two parallel sidewalls.
3 . The bit of claim 2 , wherein one of the sidewalls forms an acute angle and the other forms an obtuse angle.
4 . The bit of claim 2 , wherein the wedge is secured immediately next to the obtuse angled sidewall.
5 . The bit of claim 1 , wherein the wedge has two obtuse angled sides.
6 . The bit of claim 1 , further including one or more bolts through each wedge, securing both the wedge and the leg to the bit body.
7 . The bit of claim 1 , wherein the slot has two sidewalls that are not parallel to each other.
8 . The bit of claim 7 , wherein a first one of the sidewalls extends about straight outwardly from an axial center of the bit body.
9 . The bit of claim 8 , wherein the wedge is secured immediately next to the first sidewall.
10 . The bit of claim 1 , wherein an obtuse angled sidewall of the wedge is secured immediately next to an acute angled side of the leg.
11 . The bit of claim 1 , wherein a key extends from each leg into the bit body.
12 . An earth boring drill bit comprising:
one or more legs with corresponding roller cones;
a bit body having a blade and a slot for receiving the leg, wherein the slot has two parallel sidewalls, such that one of the sidewalls forms an acute angle and the other forms an obtuse angle; and
one or more wedge between the leg and the slot fixing the leg within the slot.
13 . The bit of claim 12 , wherein the wedge is secured immediately next to the obtuse angled sidewall.
14 . The bit of claim 12 , further including one or more bolts through each wedge, securing both the wedge and the leg to the bit body.
15 . The bit of claim 12 , wherein an obtuse angled sidewall of the wedge is secured immediately next to an acute angled side of the leg.
16 . The bit of claim 12 , wherein a key extends from each leg into the bit body.
17 . A method of assembling an earth boring drill bit, the method comprising the steps of:
selecting one or more legs from a plurality of pre-manufactured legs;
selecting a bit body from a plurality of pre-manufactured bit bodies, the bit body having a slot for receiving the leg;
bolting the leg within the slot; and
bolting a wedge, the wedge having at least one angled side, between the leg and a sidewall of the slot, thereby securing the leg within the slot without welding.
18 . The method of claim 17 , wherein tightening a bolt through the wedge presses the leg against the sidewall of the slot.
19 . The method of claim 17 , further including placing the wedge immediately next to an obtuse angled sidewall of the slot.
20 . The method of claim 17 , further including placing the wedge immediately next to an acute angled side of the leg.