The take-off needle comprises a main hollow lance having a distal end
adapted to perform a pricking operation, said hollow lance being
connected to two pipes each provided with a spigot for it to be connected
to a tube, said needle further comprising a body for holding the main
hollow lance, said holding body defining two internal cylindrical
surfaces forming said pipes, the main hollow lance comprising, at its
proximal end, a sleeve having an internal channel of which the distal end
is connected to the proximal end of the main hollow lance, and of which
the proximal end opens into the holding body, said sleeve comprising at
its proximal end two crescent-shaped surfaces inclined towards the
interior of the internal channel and towards the distal end of the
sleeve, each of said crescent-shaped surfaces being disposed so as to
extend in line with one of the internal cylindrical surfaces of the
holding body.