Shank adaptor with reinforced flushing slot

Patent metadata

Field	Value
Publication number	US-2017145756-A1
Application number	US-201515310202-A
Country	US
Kind code	A1
Filing date	May 4, 2015
Priority date	May 13, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

A rock drilling shank adaptor includes an elongate body having an internal flushing bore and an entry hole through the sidewall of the adaptor in fluid communication with the internal bore. The adaptor wall at the region of the entry hole is reinforced such that an internal diameter of the flushing bore at the reinforced region is less than an internal diameter of the bore at a position axially beyond the reinforced region.

First claim

1 . A rock drilling shank adaptor comprising:
an elongate body having a first end arranged to be positioned towards a piston and a second end arranged to be positioned towards a drill string; the body having an axially extending internal bore to allow passage of a flushing fluid to the drill string via the second end; not more than two flush holes extending radially through the body to the internal bore; and a cross sectional area of the body at an axially reinforced region at the flush holes being equal to or greater than a cross sectional area of the body at an axial position of the internal bore axially beyond the reinforced region.

2 . The adaptor as claimed in claim 1 , wherein the reinforced region extends axially at either side or at least to one side of the flush holes such that a cross sectional area of the body to at least one axial side of the flush holes is greater than the cross sectional area of the body at the a position of the internal bore axially beyond the reinforced region.

3 . The adaptor as claimed in claim 2 , wherein a wall thickness of the body at the reinforced region is greater than a wall thickness of the body at the position axially beyond the reinforced region.

4 . The adaptor as claimed in claim 1 , wherein an axial length of the reinforced region is in the range 2% to 20% of a total axial length of the adaptor.

5 . The adaptor as claimed in claim 4 , wherein the range is 4% to 15%.

6 . The adaptor as claimed in claim 1 , wherein the cross sectional area of the body at an axial position of the flush holes is in the range 0% to 50% greater than the cross sectional area at the position axially beyond the reinforced region.

7 . The adaptor as claimed in claim 1 , wherein a cross sectional area of the body at an axial position within the reinforced region but to one axial side of the flush holes is in the range 10 to 50% greater than the cross sectional area at the position axially beyond the reinforced region.

8 . The adaptor as claimed in claim 3 , wherein the wall thickness of the body at the reinforced region is 30% to 60% greater than the wall thickness at the position axially beyond the reinforced region.

9 . The adaptor as claimed in claim 1 , wherein the cross sectional area of the body decreases in the axial direction from the reinforced region to the position axially beyond the reinforced region via a gradual tapered profile.

10 . The adaptor as claimed in claim 1 , wherein the flush holes each have a super ellipse shape profile.

11 . The adaptor as claimed in claim 1 , wherein an internal diameter of the body at the reinforced region is less than an internal diameter of the body at the position axially beyond the reinforced region.

12 . A rock drilling apparatus comprising:
an elongate piston; a drill string; and a shank adaptor including an elongate body having a first end arranged to be positioned towards the piston and a second end arranged to be positioned towards the drill string, the body having an axially extending internal bore to allow passage of a flushing fluid to the drill string via the second end, not more than two flush holes extending radially through the body to the internal bore, and a cross sectional area of the body at an axially reinforced region at the flush holes being equal to or greater than a cross sectional area of the body at an axial position of the internal bore axially beyond the reinforced region.

13 . The apparatus claimed in claim 12 , wherein the elongate piston includes a main length and an energy transmission end to contact the first end of the adaptor, drill string being formed from a plurality of coupled elongate rods wherein a rearwardmost drill rod of the string is coupled to the second end of the adaptor.

14 . The apparatus as claimed in claim 13 , wherein the reinforced region is configured such that an impedance mismatch between the adaptor and the rearwardmost drill rod is less than 5%.

15 . The apparatus as claimed in claim 13 , wherein the reinforced region is configured such that an impedance mismatch between the adaptor and the rearwardmost drill rod is less than 2%.

Assignees

• Sandvik Intellectual Property

Inventors

• Lejon Susanne
• Persson Magnus
• Jansson Tomas Sh

Classifications

• E21B10/36

  Percussion drill bits ({with helical conveying portion E21B10/445;} characterised by wear resisting parts E21B10/46) · CPC title

• E21B10/60

  characterised by conduits or nozzles for drilling fluids (for roller bits E21B10/18; for percussion drill bits E21B10/38) · CPC title

• E21B17/03 Primary

  between drilling rod or pipe and drill motor {or surface drive}, e.g. between drilling rod and hammer · CPC title

• E21B10/38 Primary

  characterised by conduits or nozzles for drilling fluids · CPC title

• E21B21/01

  Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes · CPC title