# US 7,744,164 B2 · Shield of a degradation assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,164 B2 - Document ID: US7744164B2 - Status: Granted - Kind: B2 - Application number: 12/177,599 - Filed: 2008-07-22 - Published: 2008-12-18 - Granted: 2010-06-29 - Earliest claimed: 2006-08-11 - Assignees: Schluimberger Technology Corporation - Inventors: David R. Hall; Ronald Crockett; Scott Dahlgren - Web page: https://patentgrep.com/patent/US7744164B2 ## CPC - E21C 35/183: with inserts or layers of wear-resisting material {(drill bits with wear-resistant parts E21B10/46)} - A47C 3/00: Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats (A47C1/00, A47C4/00 take precedence) - B28D 1/186: {Tools therefor, e.g. having exchangeable cutter bits (B28D1/181 takes precedence; bits for picks or pick-holders for mining or quarrying E21C35/18)} - E21B 10/16: characterised by tooth form or arrangement - E21B 10/36: Percussion drill bits ({with helical conveying portion E21B10/445;} characterised by wear resisting parts E21B10/46) - E21C 35/18: Mining picks; Holders therefor (planing knives E21C27/44) - E21C 35/197: using sleeves, rings or the like, as main fixing elements - E21C 35/1831: {Fixing methods or devices} - E21C 35/188: {characterised by adaptations to use an extraction tool} - E21C: MINING OR QUARRYING - A47C: CHAIRS; SOFAS; BEDS - B28D: WORKING STONE OR STONE-LIKE MATERIALS - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract In one aspect of the present invention, a degradation assembly comprises a shank with a forward end and a rearward end, the rearward end being adapted for attachment to a driving mechanism, with a shield rotatably attached to the forward end of the shank. The shield comprises an underside adapted for rotatable attachment to the shank and an impact tip disposed on an end opposing the underside. A seal is disposed intermediate the shield and the shank. ## Claims ### Claim 1 A degradation assembly comprising: a shank comprising a forward end and a rearward end, the rearward end being adapted to be retained in a holder attached to a driving mechanism; an underside of a shield rotatably connected to the forward end of the shank; and the distal most surface of the forward end is a load bearing surface; the shield also comprising a carbide bolster bonded to the impact tip at an end opposing the underside; wherein the carbide bolster is disposed axially intermediate the impact tip and a steel portion of the shield along the assembly's central axis; wherein a first and second cylindrical bearing surface on a large and smaller diameter of the forward end respectively is separated by a non-bearing, substantially conical portion of the forward end. ### Claim 2 (depends on 1) The assembly of claim 1, wherein the distal most surface comprises a flat. ### Claim 3 (depends on 1) The assembly of claim 1, wherein the distal most surface comprise a wear resistant material. ### Claim 4 (depends on 3) The assembly of claim 3, wherein the wear resistant material comprises chromium, nitride, aluminum, boron, titanium, carbide and combinations thereof. ### Claim 5 (depends on 1) The assembly of claim 1, wherein the distal most surface comprises a diamond. ### Claim 6 (depends on 1) The assembly of claim 1, wherein the distal most surface comprises ceramic with a hardness greater than tungsten carbide. ### Claim 7 (depends on 1) The assembly of claim 1, wherein the distal most surface comprise a carbide. ### Claim 8 (depends on 1) The assembly of claim 1, wherein the distal most surface is work hardened, cold hardened, or combinations thereof. ### Claim 9 (depends on 1) The assembly of claim 1, wherein the reward end is substantially cylindrical and adapted to be press fit within the holder. ### Claim 10 (depends on 1) The assembly of claim 1, wherein the shank is adapted to be rotationally stationary with respect to a driving mechanism in which the shank is secured and the shield is adapted to rotate around the shank. ### Claim 11 (depends on 1) The assembly of claim 1, wherein the forward end is tapered. ### Claim 12 (depends on 1) The assembly of claim 1, wherein the forward end comprises at least one step. ### Claim 13 (depends on 1) The assembly of claim 1, wherein the forward portion of the at least one step is also a load bearing surface. ### Claim 14 (depends on 1) The assembly of claim 1, wherein the shank comprises a radially extending flange below the shield. ### Claim 15 (depends on 14) The assembly of claim 14, wherein a gap exist between the flange and the shield, when the shield is fully connected to the forward end. ### Claim 16 (depends on 1) The assembly of claim 1, wherein a carbide bolster is attached to the shield. ### Claim 17 (depends on 16) The assembly of claim 16, wherein an impact tip is bonded to the bolster. ### Claim 18 (depends on 17) The assembly of claim 17, wherein the tip comprises a carbide substrate bonded to polycrystalline diamond. ### Claim 19 (depends on 18) The assembly of claim 18, wherein the substrate is less than 10 mm thick. ### Claim 20 (depends on 1) The assembly of claim 1, wherein the distal most surface comprises a hole.