US 12,345,103 B2
Drill bit assembly comprising an expandable retaining sleeve
Jouni Koskinen, Tampere (FI); and Olivier Bruandet, Tampere (FI)
Assigned to SANDVIK MINING AND CONSTRUCTION TOOLS AB, Sandviken (SE); and SANDVIK MINING AND CONSTRUCTION OY, Tampere (FI)
Appl. No. 18/283,389
Filed by SANDVIK MINING AND CONSTRUCTION OY, Tampere (FI); and SANDVIK MINING AND CONSTRUCTION TOOLS AB, Sandviken (SE)
PCT Filed Mar. 22, 2022, PCT No. PCT/EP2022/057475
§ 371(c)(1), (2) Date Sep. 21, 2023,
PCT Pub. No. WO2022/200342, PCT Pub. Date Sep. 29, 2022.
Claims priority of application No. 21164079 (EP), filed on Mar. 22, 2021.
Prior Publication US 2024/0167343 A1, May 23, 2024
Int. Cl. E21B 17/046 (2006.01); E21B 10/36 (2006.01); E21B 19/18 (2006.01)
CPC E21B 17/046 (2013.01) [E21B 10/36 (2013.01); E21B 19/18 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A hammer drill assembly for coupling to a drill string having an axially forward end and an axially rearward end and a longitudinal axis, the assembly comprising:
a drill bit positioned at the forward end having a drill head and a bit shaft; and
an annular driver sub provided axially rearward of the drill bit, wherein the bit shaft is accommodated at least partially inside the driver sub, wherein the drill bit is releasably attached to the driver sub via a retaining sleeve, the retaining sleeve being elastically deformable, and wherein the retaining sleeve is radially positioned at least partially between the driver sub and the drill bit, the retaining sleeve comprising:
a plurality of tips positioned inside the driver sub;
a ring positioned axially forward of the tips; and
a body that extends between the ring and the plurality of tips at its rearward end, wherein each tip of the plurality of tips has a radially inwardly projecting inner retaining shoulder and a radially outwardly projecting outer retaining shoulder, and wherein there is an inner retaining face on the inner retaining shoulder and an outer retaining face on the outer retaining shoulder.