Flow control valve for rock bits

• US 4,154,313 A
• Filed: 04/28/1978
• Issued: 05/15/1979
• Est. Priority Date: 04/28/1978
• Status: Expired due to Term

• Current Assignee: Dresser Industries Incorporated (Halliburton Company)
• Original Assignee: Dresser Industries Incorporated (Halliburton Company)
• Inventors: Dysart, Theodore R., McKay, Don C.
• Primary Examiner(s): Leppink, James A.
• Application Number:
  US05/901,057
• Time in Patent Office: 382 Days
• Field of Search: 175/227, 175/318, 175/337, 308/8.2
• US Class Current: 175/318
• CPC Class Codes: E21B 10/18 characterised by conduits or nozzles for drilling fluids
• CPC Class Codes: E21B 21/002 Down-hole drilling fluid separation systems containers comprising collecting means with a strainer E21B27/005; subsoil filtering E21B43/02; down-hole production separators E21B43/38
• CPC Class Codes: E21B 21/10 Valve arrangements in drilling-fluid circulation systems

Abstract

A rotary rock bit with passageways for conducting air or other gaseous fluid to cool the bearings and flush cuttings from the borehole includes valve means for controlling the entry of water into the bearings. The stream of air or other gaseous fluid is directed through a valve system that prevents water from reaching the bearings. In one embodiment a truly positive backflow shutoff valving arrangement through both the nozzle and bearing passageways provides a means for more effectively preventing water and cuttings from entering the bearings and bearing passageways of the bit.

Claims

1. A drill bit for air drilling, comprising:

a body;

a plurality of cutter means journaled on said body;

a recess in said body forming a chamber;

a plurality of jet passageways intersecting said chamber and oriented to direct a jet of air between adjacent cutter means;

a cooling passageway for each of said cutter means intersecting said chamber and arranged to discharge air into the journals for said cutter means;

a hollow member disposed substantially coaxially in said recess and having an open lower end in substantial sealing engagement with said body providing communication between the interior of said recess and said cooling passageways, said hollow member having its upper end perforated forming a screen;

a resilient member disposed within said hollow member in juxtaposition with said screen and being movable away from said screen to permit flow therethrough into said cooling passageways and movable toward said screen to substantially prevent flow from said cooling passageway therethrough;

a conical cover connected to said hollow member and positioned over said perforated upper end of said hollow member for causing air to change direction before it enters the perforated upper end of said hollow member; and

a perforate member of frusto-conical configuration located in said upper chamber encircling said hollow member, said perforate member having its inner periphery connected with said hollow member relatively below said screen and having its outer periphery disposed relatively above said inner periphery in engagement with said body in the upper chamber and above the intersections of said jet passageways with said upper chamber.

2. A drill bit for air drilling, comprising:

a body;

a plurality of cutter means journaled on said body;

a recess in said body forming upper and lower chambers;

a plurality of jet passageways extending therethrough intersecting said upper chamber and oriented to direct a jet of air between adjacent cutter means;

a cooling passageway extending therethrough for each of said cutter means intersecting said lower chamber and arranged to discharge air into the journals for said cutter means;

a hollow member disposed substantially coaxially in said recess and having an open lower end located in said lower chamber in substantial sealing engagement with said body providing communication between the interior of said hollow member and said cooling passageways, said hollow member having its upper end perforated forming a screen;

a first resilient member disposed within said hollow member in juxtaposition with said screen and being movable away from said screen to permit flow therethrough into said cooling passageways and movable toward said screen to substantially prevent flow from said cooling passageway therethrough;

a perforate member of frusto-conical configuration located in said upper chamber encircling said hollow member, said perforate member having its inner periphery connected with said hollow member relatively below said screen and having its outer periphery disposed relatively above said inner periphery in engagement with said body in the upper chamber and above the intersections of said jet passageways with said upper chamber; and

a conical cover disposed in contact with said hollow member and positioned over said perforate upper end of said hollow member for causing air to change direction before it enters the perforated upper end of said hollow member.