Patent ID: 8636265

Claim:
An improved motorized winch for raising and lowering objects by means of cables with respect to a facility, comprising: an elongated tubular support enclosure having a longitudinal direction and having means for mounting in a fixed position with respect to the facility, the tubular support enclosure having top, bottom, and side walls extending in the longitudinal direction, cable guiding means for receiving and guiding cables and mounted in a fixed position with respect to and supported by the tubular support enclosure on the top or bottom wall of the tubular support enclosure, the supporting top or bottom wall having access openings for passage of cables, a winch unit mounted inside, to, and supported by the tubular support enclosure, the winch unit comprising: an elongated drum having a longitudinal axis extending in the longitudinal direction and having on its outside a helical groove configured to receive adjacent strands of a cable and mounted for rotation about and translation relative to its longitudinal axis on supports inside the tubular support enclosure and with respect to the tubular support enclosure, one or more cables engaging the drum grooves and passing from the outside of the drum through the access openings in the supporting top or bottom wall to and over the cable guiding means to the object, each cable when wound up on the drum occupying an axially-extending section having a given length of the drum grooves, drive means for rotating the drum, the top, bottom, and side walls of the tubular support enclosure extending at least over the drum in the longitudinal direction, said drum, and cables being connected to the cable guiding means such that rotation of the drum causes each cable to wind or unwind on or off the drum grooves to move the object up or down with respect to the facility while simultaneously translating back and forth, parallel to its longitudinal axis, relative to the tubular support enclosure in synchronization with the rotation of the drum controlling the cable runs to their respective cable guiding means to achieve zero fleet angle while the drum is translated over the given length of the axially-extending section, the mounting of the winch unit inside the tubular support enclosure and the mounting of the cable guiding means being such that access for maintenance and repairs can be had to the cables, drive means and cable guiding means without removing the tubular support enclosure from its fixed mounting to the facility.