US 7,320,560 B2
Controlled expansion of rock bolt
Tommy Persson, Dylta-Bruk (Sweden); Morgan Kanflod, Örebro (Sweden); Fredrik Öberg, Örebro (Sweden); Tapio Toivonen, Örebro (Sweden); Niclas Örjas, Örebro (Sweden); Hans Gustavsson, Örebro (Sweden); and Göran Sjöstedt, Örebro (Sweden)
Assigned to Atlas Copco Rock Drills AB, Orebro (Sweden)
Appl. No. 10/555,026
PCT Filed May 12, 2004, PCT No. PCT/SE2004/000733
§ 371(c)(1), (2), (4) Date Oct. 27, 2005,
PCT Pub. No. WO2004/099570, PCT Pub. Date Nov. 18, 2004.
Claims priority of application No. 0301377 (SE), filed on May 12, 2003.
Prior Publication US 2007/0036614 A1, Feb. 15, 2007
Int. Cl. E21D 21/00 (2006.01); E21D 20/00 (2006.01)
U.S. Cl. 405—259.3  [405/259.1] 20 Claims
OG exemplary drawing
 
1. A method for manual installation of expandable rock bolts by pressurisation, including manual connection of a pressure source to a rock bolt to be expanded, characterised in that the method comprises the steps of:
an operator starting a sequence whereby the rock bolt is pressurised to a predetermined pressure, and
ensuring by means of said sequence, and by an apparatus comprising a control system comprising means for ensuring that said predetermined pressure is held during a predetermined period of time, that the predetermined pressure is kept for a predetermined period of time.