Mandrel for stretch film rolls

摘要

An adjustable mandrel for use with cored, or coreless rolls of stretch film is disclosed. The mandrel comprises a cylindrical shaft and a sheath. The shaft and sheath each comprise slanted regions that slide against each other when the shaft is moved relative to the sheath, and this sliding movement causes the radial displacement of the sheath such that the mandrel expands to press against the inner surface of a roll of stretch film. The displaced sheath portions retract when the shaft and sheath are disengaged and can be moved from the roll and reused. The even pressure exerted by the mandrel across the roll prevents deformation of the roll and waste of the film.

主权项

1. An adjustable mandrel for securing a rolls of material from the inner surface of said roll, the adjustable mandrel having an open conformation and a closed conformation, and comprising a cylindrical shaft, a sheath surrounding said cylindrical shaft, and at least two tension means for restricting movement of the sheath,
a. said cylindrical shaft comprising
i. an outer face, an inner face, a first end, and a second end, said cylindrical shaft also comprising a longitudinal axis and a radial axis transverse to the cylindrical shaft's longitudinal axis,ii. said outer face further comprising
1. at least two raised inclined plane segments, each said inclined plane segment having a slope, b. said sheath composed of at least two sections of predominantly equal diameter circular arcs and comprising
i. an outer face, an inner face, a first end, and a second end, said sheath also comprising a longitudinal axis parallel to the cylindrical shaft's longitudinal axis and a radial axis transverse to the longitudinal axis and parallel to the cylindrical shaft's radial axis,ii. the sheath's inner face further comprising
1. at least two raised inclined plane segments, each said inclined plane segment having a slope, said slopes being complimentary to the cylindrical shaft's outer face's inclined plane slopes so that as the shaft's inclined planes slide against the cylindrical shaft's inclined planes the sheath's sections are displaced along the sheath's radial axis, c. said tension means capable of constricting the radial movement of the sheath's sections and causing these sections to retract along the sheath's radial axis towards the cylindrical shaft when the sheath's inclined plane segments are separated from the corresponding inclined plane segments located on the cylindrical shaft, thereby placing the mandrel in its closed conformation, d. the tension means further being able to stretch in response to the movement of the sheath's sections being moved away from the cylindrical shaft along the sheath's radial axis.