US 12,291,925 B1
Underreamer drill hammer
Warren Thomas Lay, Catawba, VA (US); and Austin C. Hine, New Florence, PA (US)
Assigned to Center Rock Inc., Berlin, PA (US)
Filed by Center Rock Inc., Berlin, PA (US)
Filed on Oct. 20, 2023, as Appl. No. 18/491,085.
Int. Cl. E21B 10/36 (2006.01)
CPC E21B 10/36 (2013.01) 21 Claims
OG exemplary drawing
 
1. An underreamer drill hammer comprising:
a canister having:
a housing having an outer diameter,
a proximal end configured for attachment to a drill string,
a plurality of percussive drill hammers housed within the housing, each percussive drill hammer having a single drill bit movable between a radially retracted position and a radially extended position; and
a stop about a distal end of the canister for engaging the drill bit.