Published in the May 2007 American Longwall Magazine
The Super Turbo Bolter is a compressed air operated, telescopic-leg type drilling and bolting machine used for the installation of resin bonded rock bolts in underground roadways.
The machine is lightweight, portable and offers a large degree of flexibility in terms of the bolting pattern and operating height.
The Super Turbo Bolter consists of an air motor and a drill unit mounted on a telescopic leg which usually has two or three extending sections. The operations of the machine, which include drill rotation, leg thrust and water feed, are all via a centralized rigid control handle, which is connected to the head unit by means of a distribution pin.
The telescopic leg provides the thrust to the four-piston motor, which rotates the drill chuck through a crankshaft and gearbox. In this way the drill rod and drill bit can be rotated and thrust through the roof strata to drill the hole.
Similarly, with the use of an adaptor, the roof bolt can be spun and thrust through resin capsules, mixing the resin and installing the bolt. Finally, the torque from the motor can be used to “break out” the shear pin on the nut end of the bolt, allowing a washer plate to be tightened up to the strata if required.
The Super Turbo Bolter is designed to be moved and located in position by hand and is fitted with a lifting handle attached to the base and carrying handles on either side of the head unit. By the use of these handles one man can easily lift and move the machine to the next bolting position. The handles on either side of the head unit are also used by the operator to support the machine whilst preparing to start drilling.
The Super Turbo Bolter has also been designed and constructed with the aim of reducing vibration produced by the machine to the lowest possible level.
Due to the reduced fixed height achieved by side mounting the motor, rather than a top mounting, the design of the Super Turbo Bolter enables it to achieve greater leg extension on two leg stages. This allows almost 50% more thrust to be developed. This design has the further benefits of faster drilling rates and fewer drill rod changes.
The drive head comprising the air motor and drill unit is a cast nylon component, which is subsequently machined and fitted with pistons, crankshaft, gears, bearings and seals.
On retraction of the legs, an integral dump valve directs the used air not directly to atmosphere but through the transmission, therefore providing constant lubrication to the moving parts. This reduces wear, whilst at the same time reducing the noise emission from the dump valve.
The machine works at its peak performance with 6 bar dynamic air pressure and 3.4cu.m/min airflow. Even at 4 bar however, the Super Turbo will drill and bolt satisfactorily.
Super Turbo bolters can be supplied for either water flushed or air flushed drilling.
Five standard leg sizes cover every option from a closed height of 1m to an open height of 4.6m.
The standard chuck option is the 19mm hexagonal chuck. The chuck allows rapid drill rod changes and provides good alignment. A high degree of sealing occurs between the drill rod and the base of the chuck whilst drilling. Rods with or without an O-ring water seal can be used. The chuck is also fitted with a long life, high pressure water seal which prevents the ingress of water into the gearbox.
Alternatively the machines can be supplied with an externally threaded chuck. A drill rod captivation system can then be employed or, in conjunction with a threaded “E” type adaptor, various chuck extensions can be fitted or the “E” type tubular male/female extension drill rods can be used. This type of drill rod system is particularly suited to the higher thrusts associated with cable bolting.
