(57) A geotechnical device, which among other purposes is useful for sampling soil or
rock in percussive boring or rotary drilling operations, comprises a one-piece, normally
flat member (1) of resilient material, having a continuous circular circumference
and having at least one projection extending from said circumference towards or beyond
its centre. In one preferred form the device comprises a circular disc (1) of resilient
material, having at least three radial cuts or slots (2) extending from the centre
of the disc towards its circumference and having one or more concentric ribs (5) between
the centre (3) of the disc and the radially outer limit (4) of the cuts or slots (2).
|
|
