Retention system for retaining deck bushing of drilling machine

A drilling machine comprising:

• a frame;
• a mast system supported on the frame;
• a mast weldment coupled to the frame;
• a drill string;
• a work tool coupled to the drill string;
• a deck bushing movable relative to the drill string;
• and
• a retention system for retaining the deck bushing in a raised state to facilitate an inspection and/or a replacement of the work tool from the drill string of the drilling machine, the retention system including:
• a pipe rack coupled to the mast weldment, wherein the pipe rack is rotatable between a first pipe rack position and a second pipe rack position;
• a retention arm assembly coupled with the pipe rack, the retention arm assembly including a retention element coupled proximal to a bottom end of the drill string, wherein the retention element defines a maximum diameter that is greater than an inner diameter of the deck bushing:
• wherein the retention arm assembly is rotatable relative to the pipe rack between a first arm position and a second arm position, wherein, when the pipe rack is in the first pipe rack position and the retention arm assembly is in the first arm position, the retention arm assembly is disengaged from the deck bushing, and wherein, when the pipe rack is in the second pipe rack position and the retention arm assembly is in the second arm position, the retention arm assembly is engaged with the deck bushing to retain the deck bushing in the raised state to facilitate the inspection and/or the replacement of the work tool from the drill string of the drilling machine;
• wherein, when the pipe rack is rotated to the first pipe rack position from the second pipe rack position and the retention arm assembly is rotated to the first arm position from the second arm position, the retention element is engaged with the deck bushing to retain the deck bushing on the drill string;
• and
• a pipe positioner system coupled to the mast weldment, wherein the pipe positioner system contacts the drill string to guide and center a movement of the drill string along a vertical axis before the retention arm assembly engages with the deck bushing, and wherein the pipe positioner system includes at least one support arm that contacts with the drill string to facilitate the movement of the drill string along the vertical axis.

A method for retaining a deck bushing of a drilling machine, the deck bushing is movable relative to a drill string of the drilling machine, the method comprising:

• engaging a pipe positioner system of the drilling machine with the drill string of the drilling machine to guide and center a movement of the drill string along a vertical axis, wherein the pipe positioner system includes at least one support arm that contacts with the drill string to facilitate the movement of the drill string along the vertical axis;
• raising the drill string such that a work tool of the drilling machine is raised above a mast base plate of the drilling machine;
• rotating a pipe rack from a first pipe rack position to a second pipe rack position;
• rotating a retention arm assembly from a first arm position to a second arm position, wherein the retention arm assembly is coupled with the pipe rack of the drilling machine, and wherein, when the retention arm assembly is in the first arm position, the retention arm assembly is disengaged from the deck bushing, wherein the deck bushing defines a upper end and a lower end opposite the upper end, wherein the deck bushing includes a flange defined at the upper end and a bottom surface defined at the lower end;
• engaging the retention arm assembly with the flange of the deck bushing or the bottom surface of the deck bushing based on the rotation of the pipe rack to the second pipe rack position;
• retaining, by the retention arm assembly, the deck bushing in a raised state based on an engagement of the retention arm assembly with the deck bushing to facilitate an inspection and/or a replacement of the work tool from the drill string;
• disengaging the retention arm assembly and the pipe rack from the deck bushing after the inspection and/or the replacement of the work tool;
• reseating the deck bushing on the mast base plate;
• and
• lowering the drill string of the drilling machine to a Ready-To-Drill state or a Ready-To-Tram state.