Film fitting head
Disclosed herein is a film fitting head which holds a tubular film fitted on a mandrel in a stable position and can prevent the film from rotating and being displaced in a peripheral direction. The film fitting head ( 40 ) includes a mandrel (M) for receiving a tubular film (L) in a fitted state in a film supply position, feeding the tubular film in a film fitting position, and fitting the tubular film onto a body portion of a container. The mandrel (M) includes a film holding portion ( 85 ) provided above a lifting member ( 88 ) located in a standby position. An outer peripheral surface of the film holding portion ( 85 ) has a tapered surface that is tapered down toward a top, and an outer peripheral length of a lower end ( 85 a ) of the film holding portion ( 85 ) is set to be approximately equal to a peripheral length of the tubular film (L) in an open state.
1. A film fitting head for fitting a tubular film on a body portion of a container from below the container, the film fitting head comprising:
a mandrel comprising an outer peripheral surface providing a film holding portion, and a tapered tip portion comprising a frustum form and arranged between the film holding portion and a top of the mandrel, wherein the mandrel is configured to:
circulate through a film supply position and a film fitting position,
receive the tubular film in an open state in the film supply position,
hold the tubular film on the film holding portion below the tapered tip portion,
move to the film fitting position, and
guide and to feed the tubular film to the body portion of the container when the tubular film is lifted in the film fitting position and fitting the tubular film on the body portion of the container; and
a lifting member configured to move up from a standby position to a film lifting position in the film fitting position to lift the tubular film held on the film holding portion of the mandrel toward the body portion of the container, wherein
the mandrel includes the film holding portion disposed above the lifting member located in the standby position,
the film holding portion has a tapered surface that is tapered down toward the tapered tip portion, and
an outer peripheral length of a lower end of the film holding portion is set to be approximately equal to a peripheral length of the tubular film in an open state.
2. The film fitting head according to claim 1 , wherein
the mandrel comprises
a mandrel shaft having an outer peripheral surface having a plurality of guide grooves formed in a shaft axial direction; and
a plurality of film feeding guides movable in a vertical direction along the guide grooves between
a film receiving position in which an upper end of each of the film feeding guides respectively arranged in the guide grooves of the mandrel shaft is retreated below the tapered tip portion and
a film feeding position in which the upper end projects around the tapered tip portion to allow the tubular film to be fed in an open state to be approximately the same size as an outer circumferential shape of the body portion of the container, and
the film holding portion composed of the tapered surface in the mandrel is comprised of external surfaces of the mandrel shaft and the film feeding guides.
3. The film fitting head according to claim 2 , wherein
the guide grooves of the mandrel shaft and the film feeding guides are, when viewed from the vertical direction, arranged in positions respectively corresponding to corners of the body portion having an approximately rectangular shape with rounded corner portions.
4. The film fitting head according to claim 1 , wherein the lifting member comprises a through hole for receiving the mandrel.
5. The film fitting head according to claim 4 , wherein the through hole comprises at least one projecting portion for engaging with a corresponding at least one groove of the mandrel.
6. The film fitting head according to claim 1 , further comprising a vertical guide component arranged parallel to the mandrel, and wherein the lifting member extends from the guide component.
7. The film fitting head according to claim 1 , wherein the tapered surface of the film holding portion comprises an angle with respect to an axial direction of the mandrel of between 2 degrees and 10 degrees.