Before a site is chosen to be exploited for its underground resources, exploration works must be done in order to accurately define what quantity of ore is contained in the rock and where it is located. The same exploration works are performed on a mine site once it is operational. Amongst all the exploration activities done, drilling the rock to get samples represents an essential activity. This can be achieved by different model of drill rigs, each involving rods that can be assembled together by the means of male to female thread connections at their ends and that are inserted one after the other behind the perforation tool.
The same principle of driving a perforation tool down into the ground by the means of threaded rods can be found in many other fields other than mining exploration. For example, the petroleum field uses drill rigs to sample the ground in search for oil reserve or to reach them; the civil engineering field uses drill rigs to sample the ground before building structures; water well works are done with drill rigs; and, service holes in underground mines also use drill rigs.
The most common way of inserting and withdrawing the rods are by means of a worker who handles them in and out of the drill unit. The operations carried by that person are very demanding physically and are the cause of many injuries in the field. For example, due to the heavy weight of the rods and their long shape, many accidents happen when the operator becomes exhausted and trips or pinches one of its limbs. Another danger related to the manipulation of the rods is that it exposes the operator to hydraulically moving mechanisms such as the rotation head, the chuck and the mast of the drill.
With the evolution of technologies, tools to improve the speed of inserting rods one after the other into a drill head or removing them from the drill head have been developed. Those tools are commonly known as rod handlers. Current rod handlers found on the market imply whether that the rods are stacked vertically on a support attached to the drill rig or that an operator participates in moving the rods in order to lay them horizontally on the ground out of the work area. Such an intervention from the operator includes lifting the whole rods or supporting one end of the rod in order to slide it into place while the other end is held and moved by a hydraulic mechanism.
Drawbacks of current rod handling tools and methods includes the risk that the operator could pinch any of his limbs or hurt himself if the rod handler makes a move that the operator would not expect. Also, stacking rods vertically can be very dangerous when working with high velocity winds or when the ground under the drill rig isn't leveled or firm enough. In those cases, the rod stack could eventually break its support due to unaccounted forces induced to its structure and then fall down or turn the whole drill rig over because of a cantilever effect.
Rod handlers are known involving horizontal stacking, but they are required to be placed in the longitudinal axis of a drill rig to grab the rods in front of the mast and drop them in line with the mast. In some cases, that requires the layout of a much longer working surface than what is allowed to setup the drill rig on and can lead to the cancellation of the drilling works or to the use of more dangerous equipment.