US 12,251,811 B2
Linerbolt removal tool improvements
David Groves, Toowoomba (AU); and Peter John Rubie, Toowoomba (AU)
Assigned to Russell Mineral Equipment Pty Ltd., Toowoomba (AU)
Appl. No. 18/282,447
Filed by Russell Mineral Equipment Pty Ltd, Toowoomba (AU)
PCT Filed Mar. 15, 2022, PCT No. PCT/AU2022/050218
§ 371(c)(1), (2) Date Sep. 15, 2023,
PCT Pub. No. WO2022/192941, PCT Pub. Date Sep. 22, 2022.
Claims priority of application No. 2021900745 (AU), filed on Mar. 15, 2021.
Prior Publication US 2024/0157533 A1, May 16, 2024
Int. Cl. B25D 17/06 (2006.01); B25D 9/08 (2006.01)
CPC B25D 17/06 (2013.01) [B25D 9/08 (2013.01); B25D 2217/0023 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A linerbolt removal tool, including:
a) a housing;
b) a moil supported for reciprocating movement along a hammer axis by the housing;
c) an inertial body located within the housing;
d) a gas charged accumulator extending from the inertial body in a rearward direction away from the moil;
e) a piston moveable within the inertial body along the hammer axis between a striking position at which the piston strikes the moil and a retracted position remote from the moil at which a rear portion of the piston is retracted within the accumulator, whereby firing the piston from its retracted position to its striking position includes causing pressurised gas within the accumulator to accelerate the piston in a forward direction toward the moil, wherein the piston has a striking end for striking the moil and an opposing rear end; and
f) a piston cap that encloses the rear end of the piston, wherein during firing, the piston and the piston cap initially accelerate together and prior to the piston reaching its striking position the piston cap separates from the piston which continues to move in the forward direction until the striking end of the piston strikes the moil, whereby the piston cap isolates the piston from the accumulator, and wherein:
i) a front portion of the piston cap impacts on an impact surface inside the accumulator to cause the piston cap to separate from the piston; and
ii) the piston includes a ledge proximate to the rear end of the piston that impacts on the front portion of the piston cap when the piston moves in the rearward direction from the striking position towards the retracted position.