GB290726A - Improvements in or relating to extracting or separating machines for withdrawing pins from hollow rock drill steels or like tools - Google Patents

Abstract

290,726. Holman, A. T., and Holman, P. M. Feb. 17, 1927. Forging rock drills; mandrels.-A machine for withdrawing the pin inserted in the end of a rock drill bit to maintain the hollow form during forging or sharpening and which may be constructed as a separate machine or form part of a power actuated forging or sharpening machine for rock drill steels or like tools comprises an abutment or other member to hold the tool against endwise movement and a device operatively connected to power actuated means so as to be pivot actuated thereby to engage the pin and then to withdraw it from the tool. In the forging or sharpening machine shown the anvil member 11 is fitted with brackets 12. 13 supporting a guide bar 14 on which a gripping jaw 16 is adapted to slide against the action of a coil spring 17. The other gripping jaw 20 is mounted on a stud 21 carried by arms 19 pivoted on pins 18 on the sides of the jaw 16, the arms 19 being connected by a link 25 to an arm 26 on a shaft 22 having a crank 27 pivoted to a loose arm 28 forked at 19 to engage a lip 31 on the hammer member 30. With the arm 28 in the position shown, a downward stroke of the hammer member first swings over the jaw 20 so as to grip the pin 33 against the jaw 16 and then moves both jaws to the right, resulting in the withdrawal of the pin from the drill bit 32 which abuts against a rest 15 on the bracket 13. The jaw 16 is toothed on both faces for reversibility when one face is worn, and a stop pin 35 between the arms 19 normally maintains the jaws at their widest distance apart.