(57) Retractable mast (1) for barriers, comprising:
- at least one fixed element (2) having an upper end (2s) and a lower end (2i), said
fixed element (2) extending along a longitudinal axis (a) for a total extension (E);
- at least one sliding element (3), having an upper part (3s) and a lower part (3i),
said sliding element (3) extending along said longitudinal axis (a) for a total extension
(L);
- at least one gap (I) between the fixed element (2) and the sliding element (3);
said gap (I) being defined from a radial distance (R), measured perpendicular with
respect to said longitudinal axis (a),
the fixed element (2) and the sliding element (3) being coupled in such a way that
the sliding element (3) can translate inside the fixed element (2) along said longitudinal
axis (a), from a first position (p1), in which it is housed in the fixed element (2)
of portion of at least 70% of its total extension (E) to a second position (p2), in
which it is extracted from the fixed element (2) of a portion of at least 50% of its
total extension (E).
The fixed element (2) has at least one groove (5) and said sliding element (3) has
at least one guide pin (7) cooperating with said groove (5), wherein the groove (5)
has at least two branches (D1, D2), one branch (D2) of the two (D1, D2) being shorter
than the other branch (D1).
The retractable mast (1) also has at least one sealing device (15),interposed between
the fixed element (2) and the sliding element (3); and the average radial distance
(R) is less than 5 mm.
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