(57) The invention concerns an control mechanism, particularly for information displayers
with interchangeable boards, provided with a higher board supporting loader (2) and
a lower board supporting loader (3), each board supporting loader being provided with
a respective control mechanism, said control mechanism comprising a hooking element
(5), operated by first operation means (6), for the dragging of a board (4) while
is wound and of a board (4) while is unwound, at least a first microswitch (8) provided
along the vertical path of said hooking element (6), controlling the stop of said
first operation means (6), a wheel (10), rotating by said operation means, provided
with a number of eccentric peripheral surfaces (11), substantially equidistant, and
in number corresponding to the number of boards (4) provided on the respective board
supporting loader (2, 3), at least a second microswitch (12) interacting with said
eccentric surfaces (11), pre-programmed control means being provided determining the
motion of a pitch of said wheel (10) having the eccentric surfaces in a direction
to release the wound board (4), up to bring the first eccentric surface (11) in engagement
with said second microswitch (12), the motion of said wheel (10) in the opposite direction
of a number of pitches sufficient to bring the same in engagement with said second
microswitch (12) the eccentric surface (11) corresponding to the following board (4)
to be brought shown, the stop of said second operation means and the start of the
first operation means (6) in the opposite direction with respect to the preceding.
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