Portable drilling rig with manual and automatic reversing switches

摘要

A drilling apparatus, the drill head (16) of which can be connected either to a drill (10) or a casing string (28), is also fitted with an automatic direction reversing mechanism (64) which is designed so that the driven part (14) of the drill head executes backward and forward movements of less than 90{, but preferably 20{ to 30{. In this way the drill head can also strike the casing string when sinking it. Activation of the first direction change-over switch (60) corresponds to the normal drilling mode in which the operators control the drill under manual directional control. The second direction change-over switch (62) is activated when earth is ejected by the twist drill. The drill is accelerated to full speed and the earth is ejected by the rapid reversal of direction. Activating the third direction change-over switch (64) causes the hydraulic motor (26) to be set in motion for only short time intervals in clockwise and anticlockwise directions.