FIELD: mining industry. SUBSTANCE: each concave 5 and convex 6 side face of rotary cutting bit of three-cone drill bit is manufactured in the form of surface of second order. Generating line of curve of second order has shape of curve. Center of rounding of top of cutting edge is displaced from axis of cutting bit towards concave face 5. Rounding radius of cutting edge in central part is made bigger than that at periphery. Concave 5 and convex 6 faces may be formed by spherical surfaces. Radius of spherical surface forming concave face 5 is greater than radius of spherical surface forming convex face 6 by 1.5-1.8 times and is equal to 1.8-2.2 of diameter of shank. EFFECT: improved operational characteristics. 2 cl, 9 dwg
| Title | Year | Author | Number |
|---|---|---|---|
| TIPS OF ROLLING CUTTER OF DRILL BIT | 1994 |
|
RU2057889C1 |
| CONE DRILL BIT | 1994 |
|
RU2057890C1 |
| DRILLING CUTTER BLOCK | 1992 |
|
RU2046176C1 |
| EXTENDED BIT JET NOZZLE | 1992 |
|
RU2012763C1 |
| ROLLER CUTTER OF DRILLING BIT | 2000 |
|
RU2185490C2 |
| BORE CONE BIT | 2007 |
|
RU2355863C2 |
| BORE CONE BIT | 2007 |
|
RU2355864C2 |
| ONE-CUTTER DRILLING BIT | 2011 |
|
RU2470134C1 |
| DRILL BIT | 2000 |
|
RU2179619C2 |
| SUPPORT OF DRILLING BIT | 1996 |
|
RU2107800C1 |
